/* ========================================================
   UNIFY QBANK — LIQUID GLASS DESIGN SYSTEM
   Monochrome Black & White • Frosted Glass Surfaces
   ======================================================== */

/* ── Theme Variables ── */
:root {
    /* Background layers */
    --bg-app: #060606;
    --bg-sidebar: rgba(12, 12, 12, 0.92);
    --bg-header: rgba(10, 10, 10, 0.65);
    --bg-card: rgba(255, 255, 255, 0.035);
    --bg-card-hover: rgba(255, 255, 255, 0.06);
    --bg-input: rgba(255, 255, 255, 0.04);

    /* Borders */
    --border-card: rgba(255, 255, 255, 0.08);
    --border-input: rgba(255, 255, 255, 0.1);
    --border-glass: rgba(255, 255, 255, 0.12);

    /* Text */
    --text-primary: #f0f0f0;
    --text-secondary: #a0a0a0;
    --text-muted: #606060;

    /* Monochrome accent (replacing purple) */
    --primary: #ffffff;
    --primary-glow: rgba(255, 255, 255, 0.06);
    --accent: #d4d4d4;
    --accent-glow: rgba(255, 255, 255, 0.04);

    /* Semantic colors — only place color is used */
    --success: #34d399;
    --success-bg: rgba(52, 211, 153, 0.1);
    --success-border: rgba(52, 211, 153, 0.25);

    --danger: #f87171;
    --danger-bg: rgba(248, 113, 113, 0.1);
    --danger-border: rgba(248, 113, 113, 0.25);

    --warning: #fbbf24;
    --warning-bg: rgba(251, 191, 36, 0.1);
    --warning-border: rgba(251, 191, 36, 0.25);

    /* Layout */
    --sidebar-width: 280px;

    /* Typography */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Plus Jakarta Sans', sans-serif;

    /* Glass effect */
    --glass-blur: 20px;
    --glass-highlight: inset 0 1px 0 rgba(255, 255, 255, 0.08);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --card-shadow: 0 4px 24px -8px rgba(0, 0, 0, 0.5);
    --transition-speed: 0.3s;
    --ease-glass: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Light Theme ── */
.light-theme {
    --bg-app: #f4f4f5;
    --bg-sidebar: rgba(255, 255, 255, 0.88);
    --bg-header: rgba(255, 255, 255, 0.7);
    --bg-card: rgba(255, 255, 255, 0.6);
    --bg-card-hover: rgba(255, 255, 255, 0.8);
    --bg-input: rgba(0, 0, 0, 0.03);

    --border-card: rgba(0, 0, 0, 0.07);
    --border-input: rgba(0, 0, 0, 0.1);
    --border-glass: rgba(0, 0, 0, 0.1);

    --text-primary: #111111;
    --text-secondary: #555555;
    --text-muted: #999999;

    --primary: #111111;
    --primary-glow: rgba(0, 0, 0, 0.05);
    --accent: #333333;
    --accent-glow: rgba(0, 0, 0, 0.03);

    --success: #059669;
    --success-bg: rgba(5, 150, 105, 0.08);
    --success-border: rgba(5, 150, 105, 0.2);

    --danger: #dc2626;
    --danger-bg: rgba(220, 38, 38, 0.08);
    --danger-border: rgba(220, 38, 38, 0.2);

    --warning: #d97706;
    --warning-bg: rgba(217, 119, 6, 0.08);
    --warning-border: rgba(217, 119, 6, 0.2);

    --glass-highlight: inset 0 1px 0 rgba(255, 255, 255, 0.5);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    --card-shadow: 0 4px 24px -8px rgba(0, 0, 0, 0.06);
}

/* ── Reset & Base ── */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--bg-app);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 15px;
    line-height: 1.6;
    overflow: hidden;
    transition: background-color var(--transition-speed), color var(--transition-speed);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    letter-spacing: -0.02em;
}

/* ========================================================
   LAYOUT CONTAINER
   ======================================================== */
.app-container {
    display: flex;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

/* ========================================================
   SIDEBAR — Liquid Glass Panel
   ======================================================== */
.app-sidebar {
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border-right: 1px solid var(--border-glass);
    display: flex;
    flex-direction: column;
    padding: 1.5rem 1.2rem;
    height: 100%;
    z-index: 100;
    transition: transform var(--transition-speed) var(--ease-glass), background-color var(--transition-speed);
    box-shadow: var(--glass-highlight);
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.brand-icon {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    box-shadow: var(--glass-highlight), 0 0 20px rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.brand-text h1 {
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1.1;
    color: var(--text-primary);
}

.brand-text h1 span {
    color: var(--text-secondary);
    -webkit-text-fill-color: unset;
    background: none;
    -webkit-background-clip: unset;
}

.version-tag {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

/* Sidebar Navigation */
.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.7rem 1rem;
    border-radius: 10px;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.2s var(--ease-glass);
    border: 1px solid transparent;
}

.nav-item i {
    width: 20px;
    height: 20px;
    transition: transform 0.2s var(--ease-glass);
}

.nav-item:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.06);
}

.nav-item:hover i {
    transform: translateX(2px);
}

.nav-item.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.15);
    box-shadow: var(--glass-highlight), 0 2px 12px rgba(255, 255, 255, 0.04);
    font-weight: 600;
}

.sidebar-separator {
    font-family: var(--font-heading);
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin: 2rem 0 0.75rem 0.5rem;
}

/* Database Selector */
.db-selector-list {
    flex: 1;
    overflow-y: auto;
    margin-right: -0.5rem;
    padding-right: 0.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}

/* Scrollbars — thin glass */
.db-selector-list::-webkit-scrollbar,
.subject-topics-list::-webkit-scrollbar,
.questions-stream::-webkit-scrollbar,
.explorer-main::-webkit-scrollbar,
.bookmarks-list-container::-webkit-scrollbar,
.right-sidebar-content::-webkit-scrollbar,
.palette-grid::-webkit-scrollbar {
    width: 4px;
}
.db-selector-list::-webkit-scrollbar-track,
.subject-topics-list::-webkit-scrollbar-track,
.questions-stream::-webkit-scrollbar-track,
.explorer-main::-webkit-scrollbar-track,
.bookmarks-list-container::-webkit-scrollbar-track,
.right-sidebar-content::-webkit-scrollbar-track,
.palette-grid::-webkit-scrollbar-track {
    background: transparent;
}
.db-selector-list::-webkit-scrollbar-thumb,
.subject-topics-list::-webkit-scrollbar-thumb,
.questions-stream::-webkit-scrollbar-thumb,
.explorer-main::-webkit-scrollbar-thumb,
.bookmarks-list-container::-webkit-scrollbar-thumb,
.right-sidebar-content::-webkit-scrollbar-thumb,
.palette-grid::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.08);
    border-radius: 4px;
}
.db-selector-list::-webkit-scrollbar-thumb:hover,
.subject-topics-list::-webkit-scrollbar-thumb:hover,
.questions-stream::-webkit-scrollbar-thumb:hover,
.explorer-main::-webkit-scrollbar-thumb:hover,
.bookmarks-list-container::-webkit-scrollbar-thumb:hover,
.right-sidebar-content::-webkit-scrollbar-thumb:hover,
.palette-grid::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.15);
}

.db-selector-item {
    display: flex;
    flex-direction: column;
    padding: 0.65rem 0.85rem;
    border-radius: 8px;
    border: 1px solid transparent;
    cursor: pointer;
    background: transparent;
    transition: all 0.2s var(--ease-glass);
}

.db-selector-item:hover {
    border-color: var(--border-card);
    background: rgba(255, 255, 255, 0.03);
}

.db-selector-item.active {
    border-color: rgba(255, 255, 255, 0.18);
    background: rgba(255, 255, 255, 0.06);
    box-shadow: var(--glass-highlight);
}

.db-selector-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.15rem;
}

.db-title {
    font-weight: 600;
    font-size: 0.83rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.db-badge {
    font-size: 0.6rem;
    padding: 0.12rem 0.4rem;
    border-radius: 12px;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

/* Badge variants — subtle monochrome tints */
.badge-marrow { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-cerebellum { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-dams { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-prep { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-reflex { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-egurukul { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-anki { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-medicine { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-corebtr { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-mrcp { background: rgba(255,255,255,0.08); color: var(--text-secondary); }
.badge-plab { background: rgba(255,255,255,0.08); color: var(--text-secondary); }

.db-size {
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* Active DB Status Card */
.active-db-card {
    margin-top: 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 12px;
    padding: 0.85rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    position: relative;
    overflow: hidden;
    box-shadow: var(--glass-highlight);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.active-db-info {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.active-db-info i {
    color: var(--text-secondary);
    width: 18px;
    height: 18px;
}

.active-db-details {
    flex: 1;
    overflow: hidden;
}

.active-db-name {
    font-size: 0.8rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.active-db-meta {
    font-size: 0.7rem;
    color: var(--text-muted);
}

.loader-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 2px;
    width: 0%;
    background: linear-gradient(to right, rgba(255,255,255,0.3), rgba(255,255,255,0.6));
    transition: width 0.3s ease;
}

.loader-bar.loading {
    width: 100%;
    animation: loader-pulse 1.5s infinite;
}

@keyframes loader-pulse {
    0% { opacity: 0.5; }
    50% { opacity: 1; }
    100% { opacity: 0.5; }
}

/* ========================================================
   MAIN CONTENT AREA
   ======================================================== */
.app-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
    min-height: 0;
}

/* ========================================================
   HEADER — Liquid Glass Bar
   ======================================================== */
.app-header {
    height: 64px;
    min-height: 64px;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--bg-header);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border-bottom: 1px solid var(--border-glass);
    z-index: 90;
    transition: background-color var(--transition-speed);
    box-shadow: var(--glass-highlight);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
}

.header-breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted);
}

.breadcrumb-arrow {
    width: 14px;
    height: 14px;
}

.active-crumb {
    color: var(--text-primary);
    font-weight: 600;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1.25rem;
}

/* Search Bar — Frosted pill */
.search-bar-container {
    position: relative;
    width: 300px;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 0.85rem;
    width: 16px;
    height: 16px;
    color: var(--text-muted);
}

.search-bar-container input {
    width: 100%;
    background: var(--bg-input);
    border: 1px solid var(--border-input);
    border-radius: 20px;
    padding: 0.5rem 2.5rem 0.5rem 2.2rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.85rem;
    transition: all 0.25s var(--ease-glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.search-bar-container input:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.25);
    background: rgba(255, 255, 255, 0.07);
    box-shadow: 0 0 16px rgba(255, 255, 255, 0.04);
}

.search-bar-container input:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

#searchKeyHint {
    position: absolute;
    right: 0.85rem;
    font-size: 0.65rem;
    background: var(--border-input);
    color: var(--text-muted);
    padding: 0.12rem 0.4rem;
    border-radius: 4px;
    font-weight: bold;
    pointer-events: none;
}

/* Theme Toggle */
.theme-toggle-btn {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    width: 38px;
    height: 38px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all 0.25s var(--ease-glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.theme-toggle-btn:hover {
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 0 12px rgba(255, 255, 255, 0.05);
}

.theme-toggle-btn .sun-icon { display: none; }
.light-theme .theme-toggle-btn .moon-icon { display: none; }
.light-theme .theme-toggle-btn .sun-icon { display: block; }

/* ========================================================
   VIEWPORTS SYSTEM
   ======================================================== */
.viewports-container {
    flex: 1;
    min-height: 0;
    overflow: hidden;
    position: relative;
}

.viewport-section {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    visibility: hidden;
    overflow-y: auto;
    padding: 2rem;
    transition: opacity 0.3s var(--ease-glass), visibility 0.3s var(--ease-glass);
    z-index: 10;
}

.viewport-section.active {
    opacity: 1;
    visibility: visible;
    z-index: 20;
}

#viewportExplorer {
    height: 100%;
    min-height: 0;
    overflow: hidden;
    padding: 0;
}

#viewportTestMode:has(#activeTestContainer:not(.hidden)) {
    height: 100%;
    min-height: 0;
    overflow: hidden;
    padding: 0;
}

/* ========================================================
   DASHBOARD VIEWPORT
   ======================================================== */

/* Welcome Banner */
.welcome-banner {
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    border-radius: 20px;
    padding: 2rem 2.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: var(--glass-highlight), var(--glass-shadow);
}

.welcome-text h2 {
    font-size: 1.7rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.welcome-text p {
    color: var(--text-secondary);
    max-width: 560px;
    font-size: 0.92rem;
}

.welcome-artwork {
    font-size: 4rem;
    color: var(--text-muted);
    opacity: 0.1;
    transform: rotate(15deg);
}

.floating-badge {
    width: 80px;
    height: 80px;
    animation: float 5s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(15deg); }
    50% { transform: translateY(-10px) rotate(10deg); }
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stats-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    box-shadow: var(--glass-highlight), var(--card-shadow);
    border-radius: 16px;
    padding: 1.2rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: all 0.25s var(--ease-glass);
}

.stats-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-glass);
    transform: translateY(-1px);
}

.stats-icon {
    width: 46px;
    height: 46px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.stats-icon i {
    width: 22px;
    height: 22px;
}

/* Monochrome icon backgrounds */
.icon-blue { background: rgba(255, 255, 255, 0.06); color: var(--text-secondary); }
.icon-yellow { background: rgba(255, 255, 255, 0.06); color: var(--text-secondary); }
.icon-green { background: rgba(255, 255, 255, 0.06); color: var(--success); }
.icon-red { background: rgba(255, 255, 255, 0.06); color: var(--danger); }
.icon-purple { background: rgba(255, 255, 255, 0.06); color: var(--text-secondary); }

.stats-data {
    display: flex;
    flex-direction: column;
}

.stats-label {
    font-size: 0.72rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.stats-value {
    font-size: 1.4rem;
    font-weight: 700;
    font-family: var(--font-heading);
}

/* Dashboard Split */
.dashboard-split {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1.5rem;
}

/* Content Card — Glass Surface */
.content-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 20px;
    padding: 1.5rem;
    box-shadow: var(--glass-highlight), var(--card-shadow);
    display: flex;
    flex-direction: column;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.card-header {
    margin-bottom: 1.25rem;
}

.card-header h3 {
    font-size: 1.15rem;
    font-weight: 600;
}

.card-subtitle {
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* Sources Grid */
.sources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
    gap: 0.8rem;
}

.source-card-btn {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-card);
    border-radius: 14px;
    padding: 1rem;
    text-align: left;
    cursor: pointer;
    transition: all 0.25s var(--ease-glass);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 105px;
}

.source-card-btn:hover {
    transform: translateY(-2px);
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.05);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3), var(--glass-highlight);
}

.source-card-name {
    font-weight: 600;
    font-size: 0.83rem;
    line-height: 1.3;
    color: var(--text-primary);
}

.source-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
}

.source-card-questions {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* Progress Details */
.progress-details-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.progress-item {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.progress-item-header {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    font-weight: 600;
}

.progress-item-bar-outer {
    height: 6px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 3px;
    overflow: hidden;
}

.progress-item-bar-inner {
    height: 100%;
    background: linear-gradient(to right, rgba(255,255,255,0.25), rgba(255,255,255,0.5));
    border-radius: 3px;
    transition: width 0.5s var(--ease-glass);
}

.stats-summary-box {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-card);
    border-radius: 12px;
    padding: 1rem;
}

.stats-summary-box h4 {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.03em;
}

.quick-summary-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
    text-align: center;
}

.summary-stat-box {
    display: flex;
    flex-direction: column;
}

.summary-val {
    font-size: 1.2rem;
    font-weight: 700;
    font-family: var(--font-heading);
}

.summary-lbl {
    font-size: 0.68rem;
    color: var(--text-muted);
    font-weight: 500;
}

.quick-summary-grid .summary-stat-box:nth-child(1) .summary-val { color: var(--success); }
.quick-summary-grid .summary-stat-box:nth-child(2) .summary-val { color: var(--danger); }
.quick-summary-grid .summary-stat-box:nth-child(3) .summary-val { color: var(--text-muted); }

/* ========================================================
   BUTTONS — Frosted Glass
   ======================================================== */
.danger-btn-outline {
    background: transparent;
    border: 1px solid var(--danger-border);
    color: var(--danger);
    padding: 0.7rem 1rem;
    border-radius: 10px;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all 0.2s var(--ease-glass);
}

.danger-btn-outline:hover {
    background: var(--danger-bg);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-card);
    color: var(--text-secondary);
    padding: 0.6rem 1.15rem;
    border-radius: 10px;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all 0.2s var(--ease-glass);
}

.btn-outline:hover {
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.04);
}

.primary-btn-glowing {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    box-shadow: var(--glass-highlight), 0 4px 16px rgba(255, 255, 255, 0.04);
    transition: all 0.25s var(--ease-glass);
}

.primary-btn-glowing:hover:not(:disabled) {
    transform: translateY(-1px);
    background: rgba(255, 255, 255, 0.18);
    box-shadow: var(--glass-highlight), 0 6px 24px rgba(255, 255, 255, 0.06);
}

.primary-btn-glowing:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    box-shadow: none;
}

.danger-btn-glowing {
    background: rgba(248, 113, 113, 0.15);
    color: var(--danger);
    border: 1px solid var(--danger-border);
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all 0.25s var(--ease-glass);
}

.danger-btn-glowing:hover {
    transform: translateY(-1px);
    background: rgba(248, 113, 113, 0.25);
    box-shadow: 0 6px 20px rgba(248, 113, 113, 0.15);
}

.warning-btn-outline {
    background: transparent;
    border: 1px solid var(--warning-border);
    color: var(--warning);
    padding: 0.6rem 1.15rem;
    border-radius: 10px;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all 0.2s var(--ease-glass);
}

.warning-btn-outline:hover {
    background: var(--warning-bg);
}

.warning-btn-outline.flagged-active {
    background: var(--warning);
    color: #000;
    border-color: var(--warning);
}

/* ========================================================
   QBANK EXPLORER — 3-Column Glass Grid
   ======================================================== */
.explorer-layout {
    display: grid;
    grid-template-columns: var(--explorer-left-width, 300px) minmax(0, 1fr) var(--explorer-right-width, 0px);
    gap: 0;
    height: 100%;
    min-height: 0;
    overflow: hidden;
    margin: 0;
    transition: grid-template-columns 0.35s var(--ease-glass);
}

/* Explorer Left Sidebar */
.explorer-sidebar {
    background: rgba(12, 12, 12, 0.5);
    border-right: 1px solid var(--border-card);
    display: flex;
    flex-direction: column;
    height: 100%;
    min-height: 0;
    overflow: hidden;
    transition: opacity 0.3s var(--ease-glass), border-right-color 0.3s;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.explorer-sidebar.collapsed {
    border-right-color: transparent;
    opacity: 0;
    pointer-events: none;
}

.explorer-sidebar-title {
    padding: 1.1rem 1.25rem;
    border-bottom: 1px solid var(--border-card);
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}

.subject-topics-list {
    flex: 1;
    overflow-y: auto;
    padding: 0.6rem;
}

/* Subject Tree */
.subject-node {
    margin-bottom: 0.35rem;
}

.subject-node-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.55rem 0.75rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.83rem;
    transition: background-color 0.2s var(--ease-glass);
    color: var(--text-secondary);
}

.subject-node-header:hover {
    background: rgba(255, 255, 255, 0.04);
    color: var(--text-primary);
}

.subject-node-header.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.08);
}

.subject-name-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    overflow: hidden;
}

.subject-name-text {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.subject-node-header i.chevron {
    width: 14px;
    height: 14px;
    transition: transform 0.2s var(--ease-glass);
    color: var(--text-muted);
}

.subject-node.expanded i.chevron {
    transform: rotate(90deg);
}

.topic-list-container {
    display: none;
    flex-direction: column;
    gap: 0.15rem;
    margin-left: 1rem;
    padding-left: 0.6rem;
    border-left: 1px solid var(--border-card);
    margin-top: 0.15rem;
}

.subject-node.expanded .topic-list-container {
    display: flex;
}

.topic-node-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.45rem 0.7rem;
    border-radius: 6px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s var(--ease-glass);
}

.topic-node-item:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.04);
}

.topic-node-item.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.12);
    font-weight: 600;
    box-shadow: var(--glass-highlight);
}

.topic-item-name {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-right: 0.5rem;
}

.topic-item-count {
    font-size: 0.68rem;
    background: rgba(255, 255, 255, 0.06);
    padding: 0.08rem 0.35rem;
    border-radius: 10px;
    color: var(--text-muted);
    font-weight: 500;
}

.topic-node-item.active .topic-item-count {
    background: rgba(255, 255, 255, 0.2);
    color: var(--text-primary);
}

/* Explorer Main Content Stream */
.explorer-main {
    display: flex;
    flex-direction: column;
    height: 100%;
    min-height: 0;
    min-width: 0;
    padding: 1.25rem 1.5rem;
    overflow-y: auto;
}

/* Stream Toolbar */
.stream-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.85rem;
    border-bottom: 1px solid var(--border-card);
    flex-wrap: wrap;
    gap: 0.75rem;
}

.stream-breadcrumb-bar h2 {
    font-size: 1.3rem;
    font-weight: 700;
}

.topic-tag {
    font-size: 0.72rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-card);
    padding: 0.18rem 0.55rem;
    border-radius: 20px;
    color: var(--text-secondary);
    font-weight: 500;
    display: inline-block;
    margin-top: 0.2rem;
}

.toolbar-controls {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    flex-wrap: wrap;
}

.toolbar-filters select {
    background: var(--bg-input);
    border: 1px solid var(--border-input);
    border-radius: 8px;
    padding: 0.45rem 0.85rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.83rem;
    cursor: pointer;
    transition: border-color 0.2s;
}

.toolbar-filters select:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.25);
}

/* Pagination */
.pagination-container {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.pag-btn {
    width: 30px;
    height: 30px;
    border-radius: 8px;
    background: var(--bg-input);
    border: 1px solid var(--border-input);
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s var(--ease-glass);
}

.pag-btn:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
}

.pag-btn:disabled {
    opacity: 0.25;
    cursor: not-allowed;
}

.pag-btn i {
    width: 16px;
    height: 16px;
}

.pag-text {
    font-size: 0.78rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Sub-toolbar */
.stream-sub-toolbar {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    margin-bottom: 1rem;
    padding: 0.6rem 0.85rem;
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 12px;
    flex-wrap: wrap;
    box-shadow: var(--glass-highlight);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.sub-toolbar-group {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.sub-toolbar-label {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    font-weight: 600;
}

.sub-toolbar-select {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-input);
    border-radius: 6px;
    padding: 0.35rem 0.65rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.78rem;
    cursor: pointer;
    transition: all 0.2s;
}

.sub-toolbar-select:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.2);
}

.view-mode-group {
    display: flex;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-input);
    border-radius: 8px;
    padding: 2px;
}

.view-mode-btn {
    background: none;
    border: none;
    padding: 0.3rem 0.7rem;
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--text-muted);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s var(--ease-glass);
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.view-mode-btn i {
    width: 14px;
    height: 14px;
}

.view-mode-btn:hover {
    color: var(--text-primary);
}

.view-mode-btn.active {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    box-shadow: var(--glass-highlight);
}

.light-theme .view-mode-btn.active {
    background: rgba(0, 0, 0, 0.08);
    color: var(--text-primary);
}

/* PDF Notes Grid */
.notes-explorer-section { /* handled by .hidden utility */ }

.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.note-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 14px;
    padding: 1.15rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 0.85rem;
    transition: all 0.25s var(--ease-glass);
    box-shadow: var(--glass-highlight);
}

.note-card:hover {
    transform: translateY(-2px);
    border-color: rgba(255, 255, 255, 0.2);
    background: var(--bg-card-hover);
}

.note-details {
    display: flex;
    gap: 0.75rem;
}

.note-icon {
    width: 34px;
    height: 34px;
    min-width: 34px;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.note-info {
    overflow: hidden;
}

.note-title {
    font-weight: 600;
    font-size: 0.83rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.note-lock-status {
    font-size: 0.7rem;
    color: var(--text-muted);
}

.note-download-btn {
    text-decoration: none;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-card);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.78rem;
    font-weight: 600;
    padding: 0.35rem 0.7rem;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    transition: all 0.2s var(--ease-glass);
}

.note-download-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: 0 4px 12px rgba(255, 255, 255, 0.04);
}

/* ========================================================
   QUESTIONS STREAM & CARDS
   ======================================================== */
.questions-stream {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    padding-right: 0.5rem;
}

/* Question Card — Liquid Glass */
.question-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 20px;
    padding: 1.5rem;
    box-shadow: var(--glass-highlight), var(--card-shadow);
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    transition: all 0.25s var(--ease-glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.question-card:hover {
    box-shadow: var(--glass-highlight), 0 12px 36px -10px rgba(0, 0, 0, 0.6);
    border-color: var(--border-glass);
}

.question-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding-bottom: 0.7rem;
}

.question-number-badge {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-secondary);
    padding: 0.18rem 0.6rem;
    border-radius: 6px;
    font-size: 0.73rem;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.question-actions-row {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.btn-icon-action {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.35rem;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s var(--ease-glass);
}

.btn-icon-action:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.06);
}

.btn-icon-action.starred-active {
    color: var(--warning);
}

.btn-icon-action.starred-active i {
    fill: var(--warning);
}

/* Question Body */
.question-body {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.question-text {
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.7;
    color: var(--text-primary);
}

.question-text p { margin-bottom: 0.7rem; }
.question-text ol, .question-text ul { margin-left: 1.5rem; margin-bottom: 0.7rem; }
.question-text li { margin-bottom: 0.3rem; }

.question-media-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin: 0.5rem 0;
    max-width: 100%;
}

.question-image {
    max-width: 100%;
    min-width: 0;
    max-height: 180px;
    object-fit: contain;
    border-radius: 10px;
    border: 1px solid var(--border-card);
    cursor: zoom-in;
    transition: transform 0.25s var(--ease-glass), box-shadow 0.25s;
}

.question-image:hover {
    transform: scale(1.02);
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.4);
}

/* Options — Frosted Glass Pills */
.options-list {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.option-item {
    display: flex;
    align-items: center;
    width: 100%;
    padding: 0.85rem 1.15rem;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.025);
    border: 1px solid var(--border-input);
    color: var(--text-primary);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    text-align: left;
    transition: all 0.2s var(--ease-glass);
}

.option-item:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.18);
    box-shadow: var(--glass-highlight);
}

.option-letter {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    min-width: 26px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border-card);
    margin-right: 0.75rem;
    font-weight: 700;
    font-size: 0.73rem;
    color: var(--text-secondary);
    transition: all 0.2s var(--ease-glass);
}

.option-text {
    flex: 1;
}

/* Option Feedback States */
.option-item.selected-wrong {
    background: var(--danger-bg);
    border-color: var(--danger-border);
    color: var(--danger);
}
.option-item.selected-wrong .option-letter {
    background: var(--danger);
    color: #fff;
    border-color: var(--danger);
}

.option-item.correct-reveal {
    background: var(--success-bg);
    border-color: var(--success-border);
    color: var(--success);
}
.option-item.correct-reveal .option-letter {
    background: var(--success);
    color: #fff;
    border-color: var(--success);
}

/* Explanation Panel */
.explanation-container {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-card);
    border-radius: 14px;
    overflow: hidden;
    margin-top: 0.4rem;
    transition: all 0.3s var(--ease-glass);
    box-shadow: var(--glass-highlight);
}

.explanation-header {
    background: rgba(255, 255, 255, 0.03);
    padding: 0.7rem 1.2rem;
    font-weight: 600;
    font-size: 0.83rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-card);
}

.explanation-header span.correct-ans {
    color: var(--success);
    font-family: var(--font-heading);
}

.explanation-body {
    padding: 1.2rem;
    font-size: 0.9rem;
    line-height: 1.65;
    color: var(--text-secondary);
    word-wrap: break-word;
    overflow-wrap: break-word;
    word-break: break-word;
    max-width: 100%;
}

.explanation-body img {
    max-width: 100% !important;
    height: auto !important;
    border-radius: 8px;
    margin: 0.5rem 0;
}

.explanation-body table {
    max-width: 100% !important;
    width: 100% !important;
    border-collapse: collapse;
    margin: 1rem 0;
    display: block;
    overflow-x: auto;
}

.explanation-body pre {
    white-space: pre-wrap !important;
    word-break: break-word !important;
    max-width: 100% !important;
    overflow-x: auto !important;
}

.explanation-body p { margin-bottom: 0.7rem; }
.explanation-body p:last-child { margin-bottom: 0; }
.explanation-body ul { margin-left: 1.5rem; margin-bottom: 0.7rem; }
.explanation-body li { margin-bottom: 0.2rem; }

/* Tags Footer */
.question-footer-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
    margin-top: 0.4rem;
}

.q-tag {
    font-size: 0.65rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-card);
    color: var(--text-muted);
    padding: 0.12rem 0.42rem;
    border-radius: 4px;
    font-weight: 500;
}

/* Empty States */
.empty-state-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 3rem 2rem;
    color: var(--text-muted);
}

.large-icon {
    width: 48px;
    height: 48px;
}

/* Skeleton Shimmer */
.skeleton {
    background: linear-gradient(90deg, rgba(255,255,255,0.02) 25%, rgba(255,255,255,0.06) 50%, rgba(255,255,255,0.02) 75%);
    background-size: 200% 100%;
    animation: loading-shimmer 1.5s infinite;
}

.skeleton-item {
    height: 38px;
    border-radius: 8px;
    margin-bottom: 0.45rem;
}

@keyframes loading-shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ========================================================
   BOOKMARKS
   ======================================================== */
.bookmarks-header {
    margin-bottom: 2rem;
}

.bookmarks-header h2 {
    font-size: 1.7rem;
    font-weight: 700;
}

.bookmarks-header p {
    color: var(--text-secondary);
}

.bookmarks-list-container {
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
}

.bookmark-list-item {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 14px;
    padding: 1.15rem;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1.5rem;
    cursor: pointer;
    transition: all 0.25s var(--ease-glass);
    box-shadow: var(--glass-highlight);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.bookmark-list-item:hover {
    border-color: rgba(255, 255, 255, 0.18);
    transform: translateX(3px);
    background: var(--bg-card-hover);
}

.bookmark-main-info { flex: 1; overflow: hidden; }

.bookmark-db-source {
    font-size: 0.68rem;
    color: var(--text-muted);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 0.2rem;
}

.bookmark-subject-topic {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.4rem;
}

.bookmark-question-snippet {
    font-size: 0.92rem;
    line-height: 1.4;
    color: var(--text-primary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ========================================================
   PRACTICE TEST MODE
   ======================================================== */
.max-width-md { max-width: 550px; }
.mx-auto { margin-left: auto; margin-right: auto; }
.text-center { text-align: center; }
.p-4 { padding: 1rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-auto { margin-top: auto; }
.w-full { width: 100%; }
.col-6 { width: calc(50% - 0.5rem); }
.hidden { display: none !important; }

.glow-color-purple {
    color: var(--text-secondary);
    filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.08));
}
.glow-color-green {
    color: var(--success);
    filter: drop-shadow(0 0 8px var(--success-bg));
}

.test-config-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin-top: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.form-group label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.form-group select,
.form-group input {
    background: var(--bg-input);
    border: 1px solid var(--border-input);
    border-radius: 10px;
    padding: 0.65rem 1rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.88rem;
    transition: border-color 0.2s;
}

.form-group select:focus,
.form-group input:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.25);
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.04);
}

.form-row {
    display: flex;
    gap: 1rem;
}

/* Test Running Layout */
.test-layout {
    display: grid;
    grid-template-columns: 1fr 260px;
    gap: 0;
    height: 100%;
    min-height: 0;
    overflow: hidden;
    margin: 0;
}

.test-main {
    flex: 1;
    overflow: hidden;
    min-height: 0;
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.test-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-card);
    padding-bottom: 0.85rem;
}

.test-timer {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.45rem 0.9rem;
    background: var(--warning-bg);
    border: 1px solid var(--warning-border);
    color: var(--warning);
    border-radius: 24px;
    font-weight: 700;
    font-size: 0.9rem;
    font-family: var(--font-heading);
}

.test-timer i {
    width: 16px;
    height: 16px;
}

.test-timer.time-warning {
    background: var(--danger-bg);
    border-color: var(--danger-border);
    color: var(--danger);
    animation: flash 1s infinite alternate;
}

@keyframes flash {
    0% { opacity: 0.7; }
    100% { opacity: 1; }
}

.test-question-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 20px;
    padding: 1.75rem;
    box-shadow: var(--glass-highlight), var(--card-shadow);
    flex: 1;
    overflow-y: auto;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.test-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Test Palette Sidebar */
.test-palette-sidebar {
    background: rgba(12, 12, 12, 0.5);
    border-left: 1px solid var(--border-card);
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    height: 100%;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.test-palette-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.close-palette-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
    border-radius: 50%;
    transition: all 0.2s ease;
}

.close-palette-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.1);
}

.close-palette-btn i {
    width: 18px;
    height: 18px;
}

.sidebar-backdrop {
    display: none;
}

.mobile-test-palette-toggle-btn {
    display: none;
}

.test-palette-sidebar h3 {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}

.palette-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 0.4rem;
    overflow-y: auto;
    max-height: calc(100vh - 340px);
}

.palette-chip {
    position: relative;
    aspect-ratio: 1;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-input);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s var(--ease-glass);
}

.palette-chip:hover {
    border-color: rgba(255, 255, 255, 0.25);
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.06);
}

.palette-chip.active {
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.3);
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.1);
}

/* Palette Chip States */
.palette-chip.answered {
    background: var(--success-bg);
    border-color: var(--success-border);
    color: var(--success);
}

.palette-chip.flagged {
    background: var(--warning-bg);
    border-color: var(--warning-border);
    color: var(--warning);
}

.palette-chip.correct {
    background: var(--success-bg);
    border-color: var(--success-border);
    color: var(--success);
}
.palette-chip.correct:hover {
    border-color: var(--success);
}

.palette-chip.incorrect {
    background: var(--danger-bg);
    border-color: var(--danger-border);
    color: var(--danger);
}
.palette-chip.incorrect:hover {
    border-color: var(--danger);
}

.palette-chip.unattempted {
    background: rgba(255, 255, 255, 0.02);
    border-color: var(--border-input);
    color: var(--text-muted);
}

.chip-bookmark-dot {
    position: absolute;
    top: 2px;
    right: 2px;
    font-size: 8px;
    color: var(--warning);
    line-height: 1;
}

/* Palette Legend */
.palette-legend {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
    font-size: 0.78rem;
    color: var(--text-secondary);
    border-top: 1px solid var(--border-card);
    padding-top: 0.85rem;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.chip-legend {
    width: 12px;
    height: 12px;
    border-radius: 3px;
    display: inline-block;
}

.legend-answered { background: var(--success-bg); border: 1px solid var(--success-border); }
.legend-flagged { background: var(--warning-bg); border: 1px solid var(--warning-border); }
.legend-unvisited { background: rgba(255,255,255,0.03); border: 1px solid var(--border-input); }
.legend-correct { background: var(--success-bg); border: 1px solid var(--success-border); }
.legend-incorrect { background: var(--danger-bg); border: 1px solid var(--danger-border); }
.legend-unattempted { background: rgba(255,255,255,0.03); border: 1px solid var(--border-input); }

/* Scorecard */
.results-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin: 1.5rem 0;
}

.results-stat-box {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 14px;
    padding: 1.2rem;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    box-shadow: var(--glass-highlight);
}

.results-stat-value {
    font-size: 1.7rem;
    font-weight: 700;
    font-family: var(--font-heading);
    color: var(--text-primary);
}

.results-stat-label {
    font-size: 0.72rem;
    color: var(--text-muted);
    font-weight: 500;
}

.results-action-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.results-action-buttons button {
    flex: 1;
}

/* ========================================================
   LIGHTBOX OVERLAY
   ======================================================== */
.lightbox-modal {
    display: none;
    position: fixed;
    z-index: 2000;
    padding-top: 50px;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background: rgba(0, 0, 0, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.lightbox-content {
    margin: auto;
    display: block;
    max-width: 90%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: 12px;
    box-shadow: 0 0 60px rgba(0, 0, 0, 0.5);
    animation: zoom 0.3s var(--ease-glass);
    cursor: zoom-in;
    transition: transform 0.25s ease, max-width 0.25s ease, max-height 0.25s ease;
}

.lightbox-content.zoomed {
    max-width: 180%;
    max-height: none;
    cursor: zoom-out;
    transform: scale(1.05);
}

@keyframes zoom {
    from { transform: scale(0.9); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.lightbox-close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: rgba(255, 255, 255, 0.6);
    font-size: 40px;
    font-weight: bold;
    transition: color 0.2s;
    cursor: pointer;
}

.lightbox-close:hover {
    color: #fff;
}

.lightbox-caption {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 700px;
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
    padding: 10px 0;
    font-size: 0.83rem;
    font-weight: 500;
}

/* ========================================================
   STREAK, EXPORT/IMPORT, ANALYTICS, NOTES
   ======================================================== */

/* Daily Streak Badge */
.streak-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--text-primary);
    padding: 0.3rem 0.85rem;
    border-radius: 20px;
    font-size: 0.78rem;
    font-weight: 600;
    margin-top: 0.6rem;
    letter-spacing: 0.02em;
    box-shadow: var(--glass-highlight);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    animation: pulseStreak 3s ease-in-out infinite;
}

@keyframes pulseStreak {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.03); }
}

/* Export / Import Buttons */
.export-import-row {
    display: flex;
    gap: 0.75rem;
    margin-top: 0.75rem;
}

.export-import-row .btn-outline {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    font-size: 0.8rem;
    padding: 0.5rem 0.75rem;
}

/* Subject Analytics */
.subject-analytics-grid {
    display: flex;
    flex-direction: column;
    gap: 0;
    padding: 0.5rem 1.25rem 1.25rem;
    max-height: 400px;
    overflow-y: auto;
}

.subject-analytics-row {
    display: grid;
    grid-template-columns: 1fr auto 120px;
    align-items: center;
    gap: 1rem;
    padding: 0.6rem 0;
    border-bottom: 1px solid var(--border-card);
    transition: background 0.2s;
}

.subject-analytics-row:hover {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 6px;
}

.subject-analytics-row:last-child {
    border-bottom: none;
}

.subject-analytics-name {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.subject-analytics-stats {
    display: flex;
    gap: 0.85rem;
    font-size: 0.75rem;
    font-weight: 500;
}

.analytics-stat {
    color: var(--text-secondary);
}

.subject-analytics-bar-outer {
    height: 5px;
    background: var(--border-input);
    border-radius: 3px;
    overflow: hidden;
}

.subject-analytics-bar-inner {
    height: 100%;
    background: linear-gradient(90deg, rgba(255,255,255,0.2), rgba(255,255,255,0.5));
    border-radius: 3px;
    transition: width 0.6s var(--ease-glass);
}

/* Question Notes */
.question-notes-section {
    border-top: 1px solid var(--border-card);
    padding: 0.55rem 1.2rem;
}

.notes-toggle {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    cursor: pointer;
    font-size: 0.78rem;
    color: var(--text-muted);
    transition: color 0.2s;
    padding: 0.2rem 0;
    user-select: none;
}

.notes-toggle i {
    width: 14px;
    height: 14px;
}

.notes-toggle:hover {
    color: var(--text-primary);
}

.notes-input-container {
    margin-top: 0.5rem;
}

.notes-input-container.hidden {
    display: none;
}

.notes-textarea {
    width: 100%;
    min-height: 55px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-input);
    border-radius: 10px;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.8rem;
    padding: 0.65rem;
    resize: vertical;
    margin-bottom: 0.4rem;
    line-height: 1.5;
    transition: border-color 0.2s;
}

.notes-textarea:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.03);
}

.notes-save-btn {
    font-size: 0.76rem !important;
    padding: 0.3rem 0.65rem !important;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.notes-save-btn i {
    width: 13px;
    height: 13px;
}

/* Keyboard Shortcuts Modal — Frosted Glass */
.shortcuts-modal {
    position: fixed;
    inset: 0;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    animation: fadeInModal 0.25s var(--ease-glass);
}

@keyframes fadeInModal {
    from { opacity: 0; }
    to { opacity: 1; }
}

.shortcuts-modal.hidden {
    display: none;
}

.shortcuts-modal-content {
    background: var(--bg-sidebar);
    border: 1px solid var(--border-glass);
    border-radius: 20px;
    padding: 2rem;
    max-width: 420px;
    width: 92%;
    box-shadow: var(--glass-highlight), 0 25px 60px -15px rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
}

.shortcuts-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.shortcuts-header h3 {
    font-family: var(--font-heading);
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
}

.shortcuts-close-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0 0.25rem;
    line-height: 1;
    transition: color 0.2s;
}

.shortcuts-close-btn:hover {
    color: var(--danger);
}

.shortcuts-grid {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.shortcut-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.shortcut-item kbd {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-input);
    border-radius: 6px;
    padding: 0.18rem 0.5rem;
    font-family: 'SF Mono', 'Monaco', 'Cascadia Mono', 'Courier New', monospace;
    font-size: 0.8rem;
    color: var(--text-primary);
    min-width: 30px;
    text-align: center;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

/* ========================================================
   MARROW SIDEBAR COLLAPSE & PALETTE
   ======================================================== */
.collapse-sidebar-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.25rem;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s var(--ease-glass);
}

.collapse-sidebar-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.06);
}

/* Explorer Right Sidebar */
.explorer-right-sidebar {
    background: rgba(12, 12, 12, 0.5);
    border-left: 1px solid var(--border-card);
    display: flex;
    flex-direction: column;
    height: 100%;
    min-height: 0;
    overflow: hidden;
    transition: opacity 0.3s var(--ease-glass), border-left-color 0.3s;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.explorer-right-sidebar.collapsed {
    border-left-color: transparent;
    opacity: 0;
    pointer-events: none;
}

.right-sidebar-title {
    padding: 1.1rem 1.25rem;
    border-bottom: 1px solid var(--border-card);
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}

.right-sidebar-title span {
    margin-right: auto;
    margin-left: 0.5rem;
}

.right-sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding: 1.1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.explorer-palette-legend {
    border-top: none;
    padding-top: 0;
    border-bottom: 1px solid var(--border-card);
    padding-bottom: 0.85rem;
}

.collapsed-active {
    color: var(--text-primary) !important;
    background: rgba(255, 255, 255, 0.08) !important;
}

/* Single Question Navigation */
.single-q-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.25rem;
    padding-top: 1.25rem;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    gap: 1rem;
}

.single-q-counter {
    font-size: 0.83rem;
    color: var(--text-muted);
    font-weight: 500;
}

.btn-outline-glow {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-input);
    color: var(--text-primary);
    padding: 0.55rem 1.1rem;
    border-radius: 10px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.25s var(--ease-glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.btn-outline-glow:hover:not(:disabled) {
    border-color: rgba(255, 255, 255, 0.25);
    box-shadow: 0 0 14px rgba(255, 255, 255, 0.06);
    background: rgba(255, 255, 255, 0.08);
}

.btn-outline-glow:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* ========================================================
   STUDY MODE (Fullscreen Practice)
   ======================================================== */
.app-container.study-mode-active .app-sidebar {
    display: none !important;
}

.study-mode-active .questions-stream {
    align-items: center;
    padding: 0 1rem;
}

.study-mode-active .question-card {
    width: 100%;
    max-width: 880px;
    margin: 0 auto;
    box-shadow: var(--glass-highlight), 0 20px 50px -15px rgba(0, 0, 0, 0.5);
}

.study-mode-active .single-q-navigation {
    width: 100%;
    max-width: 880px;
    margin: 1.25rem auto 0 auto;
}

.exit-study-btn {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-secondary);
    padding: 0.35rem 0.75rem;
    border-radius: 8px;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    display: none;
    align-items: center;
    gap: 0.4rem;
    margin-right: 0.75rem;
    transition: all 0.2s var(--ease-glass);
}

.exit-study-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    box-shadow: 0 0 12px rgba(255, 255, 255, 0.04);
}

.exit-study-btn i {
    width: 14px;
    height: 14px;
}

/* ========================================================
   RESPONSIVE BREAKPOINTS
   ======================================================== */

/* Tablets & narrow desktops */
@media (max-width: 1024px) {
    .dashboard-split {
        grid-template-columns: 1fr;
    }
    .explorer-layout {
        grid-template-columns: 220px minmax(0, 1fr);
    }
    .test-layout {
        grid-template-columns: 1fr;
    }
    .test-palette-sidebar {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        height: auto;
        max-height: 75vh;
        z-index: 500;
        background: var(--bg-sidebar);
        border-top: 1px solid var(--border-glass);
        border-left: none;
        border-right: none;
        border-radius: 24px 24px 0 0;
        box-shadow: 0 -15px 35px rgba(0, 0, 0, 0.6);
        transform: translateY(100%);
        transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        padding: 1.5rem;
    }
    .test-palette-sidebar.mobile-open {
        transform: translateY(0);
    }
    .close-palette-btn {
        display: block;
    }
    .mobile-test-palette-toggle-btn {
        display: flex;
        align-items: center;
        justify-content: center;
        position: fixed;
        bottom: 24px;
        right: 24px;
        width: 56px;
        height: 56px;
        border-radius: 50%;
        background: var(--bg-card);
        border: 1px solid var(--border-glass);
        color: var(--text-primary);
        box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5), 0 0 15px rgba(255, 255, 255, 0.05);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        z-index: 400;
        cursor: pointer;
        transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .mobile-test-palette-toggle-btn.hidden {
        display: none !important;
    }
    .mobile-test-palette-toggle-btn:hover {
        transform: translateY(-2px);
        border-color: rgba(255, 255, 255, 0.3);
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.6), 0 0 20px rgba(255, 255, 255, 0.1);
    }
    .mobile-test-palette-toggle-btn i {
        width: 24px;
        height: 24px;
    }
    .palette-grid {
        max-height: 35vh;
    }
    .search-bar-container {
        width: 220px;
    }
    .stream-toolbar {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    .explorer-right-sidebar {
        display: flex !important;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        height: auto;
        max-height: 75vh;
        z-index: 500;
        background: var(--bg-sidebar);
        border-top: 1px solid var(--border-glass);
        border-left: none;
        border-right: none;
        border-radius: 24px 24px 0 0;
        box-shadow: 0 -15px 35px rgba(0, 0, 0, 0.6);
        transform: translateY(100%);
        transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        padding: 1.5rem;
    }
    .explorer-right-sidebar.collapsed {
        opacity: 1 !important;
        pointer-events: auto !important;
        border-left-color: transparent !important;
    }
    .explorer-right-sidebar.mobile-open {
        transform: translateY(0);
    }
    .explorer-right-sidebar .collapse-sidebar-btn {
        transform: rotate(-90deg);
    }
}

/* Mobile */
@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
    }
    .app-sidebar {
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        transform: translateX(-100%);
        box-shadow: 20px 0 40px rgba(0, 0, 0, 0.5);
    }
    .app-sidebar.mobile-open {
        transform: translateX(0);
    }
    .mobile-toggle {
        display: block;
    }
    .explorer-layout {
        grid-template-columns: 1fr;
    }
    .explorer-sidebar {
        display: block !important;
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        width: 290px;
        background: var(--bg-sidebar);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        border-right: 1px solid var(--border-glass);
        z-index: 500;
        transform: translateX(-100%);
        transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        box-shadow: 20px 0 40px rgba(0, 0, 0, 0.5);
    }
    .explorer-sidebar.mobile-open {
        transform: translateX(0) !important;
    }
    .search-bar-container {
        width: 160px;
        transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .search-bar-container:focus-within {
        width: 200px;
    }
    .global-search-results {
        position: fixed;
        left: 1rem;
        right: 1rem;
        width: auto;
        max-width: none;
        top: 60px;
        box-shadow: 0 15px 35px rgba(0, 0, 0, 0.6);
    }
    #searchKeyHint {
        display: none;
    }
    .app-header {
        padding: 0 1rem;
        height: 56px;
        min-height: 56px;
    }
    .viewport-section {
        padding: 1.25rem;
    }
    .welcome-banner {
        padding: 1.5rem;
        border-radius: 16px;
    }
    .welcome-text h2 {
        font-size: 1.3rem;
    }
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .results-grid {
        grid-template-columns: 1fr;
    }
    .explorer-main {
        padding: 1rem;
    }
    .question-card {
        padding: 1.15rem;
        border-radius: 16px;
    }
    .stream-sub-toolbar {
        gap: 0.75rem;
        padding: 0.5rem 0.65rem;
    }
    .subject-analytics-row {
        grid-template-columns: 1fr auto 80px;
        gap: 0.5rem;
    }
    .subject-analytics-name {
        font-size: 0.73rem;
    }
    .export-import-row {
        flex-direction: column;
        gap: 0.5rem;
    }
    .shortcuts-modal-content {
        padding: 1.5rem;
        width: 95%;
    }
    .sidebar-backdrop {
        display: block;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        backdrop-filter: blur(4px);
        -webkit-backdrop-filter: blur(4px);
        z-index: 450;
        transition: opacity 0.3s ease;
    }
    .sidebar-backdrop.hidden {
        display: none !important;
    }
    .tag-cloud-bar {
        flex-wrap: nowrap;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        scroll-snap-type: x mandatory;
        padding: 0.75rem 1rem;
    }
    .tag-cloud-bar::-webkit-scrollbar {
        display: none;
    }
    .tag-pill {
        flex-shrink: 0;
        scroll-snap-align: start;
    }
    .breadcrumb-arrow, .active-crumb {
        display: none !important;
    }
    .stream-breadcrumb-bar h2 {
        font-size: 1.05rem !important;
        font-weight: 600;
        line-height: 1.3;
        margin-top: 0.25rem;
    }
}

/* Tiny phones */
@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    .sources-grid {
        grid-template-columns: 1fr;
    }
    .stream-sub-toolbar {
        flex-direction: column;
        align-items: flex-start;
    }
    .toolbar-controls {
        width: 100%;
        justify-content: space-between;
    }
}

/* Stream breadcrumb row adjustments */
.stream-breadcrumb-title-row {
    display: flex;
    align-items: center;
}

.toggle-sidebar-btn {
    margin-right: 0.5rem;
}

/* ========================================================
   GLOBAL SEARCH NEW UI COMPONENTS
   ======================================================== */
.search-mode-toggle {
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.4rem;
    border-radius: 50%;
    margin-right: 0.5rem;
    transition: all 0.2s ease;
}
.search-mode-toggle:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}
.search-mode-toggle.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.15);
    box-shadow: 0 0 8px rgba(255, 255, 255, 0.1);
}
.global-search-results {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    border-radius: 12px;
    max-height: 320px;
    overflow-y: auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    z-index: 1000;
}
.global-search-result-item {
    padding: 0.75rem 1rem;
    cursor: pointer;
    border-bottom: 1px solid rgba(255, 255, 255, 0.03);
    transition: background 0.15s ease;
}
.global-search-result-item:last-child {
    border-bottom: none;
}
.global-search-result-item:hover {
    background: rgba(255, 255, 255, 0.05);
}
.result-topic-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.15rem;
}
.result-topic {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-primary);
}
.result-badge {
    font-size: 0.65rem;
    padding: 0.1rem 0.35rem;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-secondary);
}
.result-meta {
    font-size: 0.72rem;
    color: var(--text-muted);
}
.global-search-no-results {
    padding: 1.5rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ========================================================
   SPACED REPETITION REVISION QUEUE (FEATURE B)
   ======================================================== */
.revision-header {
    margin-bottom: 1.5rem;
}
.revision-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}
.revision-score-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 16px;
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--glass-highlight);
}
.revision-score-val {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1;
    margin-bottom: 0.25rem;
}
.revision-score-lbl {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.04em;
}
.revision-container {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 20px;
    padding: 1.5rem;
    box-shadow: var(--glass-highlight);
    max-width: 800px;
    margin: 0 auto;
}
.revision-empty {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}
.revision-q-card-wrapper {
    margin-bottom: 1.5rem;
}
.revision-meta-info {
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    display: flex;
    gap: 0.5rem;
    align-items: center;
}
.revision-q-source {
    background: rgba(255, 255, 255, 0.08);
    padding: 0.1rem 0.4rem;
    border-radius: 6px;
    font-weight: 600;
}

/* ========================================================
   HIGH-YIELD TAG CLOUD & SMART FILTERS (FEATURE C)
   ======================================================== */
.tag-cloud-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-bottom: 1px solid var(--border-glass);
    background: rgba(255, 255, 255, 0.01);
}
.tag-pill {
    font-size: 0.72rem;
    font-weight: 550;
    padding: 0.25rem 0.65rem;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-secondary);
    border: 1px solid rgba(255, 255, 255, 0.06);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 0.3rem;
}
.tag-pill:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-1px);
}
.tag-pill.active {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.3);
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.05);
}
.tag-pill-count {
    opacity: 0.5;
    font-size: 0.65rem;
}


/* ============================================================
   GAMIFICATION + FSRS ANALYTICS (OpenMedQ-style features)
   ============================================================ */

/* --- Gamification XP / Level panel --- */
.gamification-panel {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    margin-top: 0.9rem;
    padding: 0.7rem 0.9rem;
    max-width: 420px;
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: 14px;
    box-shadow: var(--card-shadow);
}
.gamification-panel:empty { display: none; }
.gami-level-badge {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    min-width: 54px;
    height: 54px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    box-shadow: 0 4px 14px var(--primary-glow);
}
.gami-level-badge i { width: 20px; height: 20px; }
.gami-level-num { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.02em; }
.gami-body { flex: 1; min-width: 0; }
.gami-top {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 0.35rem;
}
.gami-tier { font-weight: 700; color: var(--text-primary); font-size: 0.92rem; }
.gami-xp { font-size: 0.8rem; color: var(--text-secondary); font-variant-numeric: tabular-nums; }
.gami-bar-outer {
    height: 8px;
    border-radius: 6px;
    background: var(--bg-input);
    overflow: hidden;
}
.gami-bar-inner {
    height: 100%;
    border-radius: 6px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transition: width 0.5s ease;
}
.gami-next { margin-top: 0.3rem; font-size: 0.72rem; color: var(--text-muted); }

/* --- FSRS summary boxes --- */
.fsrs-summary-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.75rem;
    margin-bottom: 1.25rem;
}
.fsrs-summary-box {
    text-align: center;
    padding: 0.9rem 0.5rem;
    background: var(--bg-input);
    border: 1px solid var(--border-card);
    border-radius: 12px;
}
.fsrs-summary-val { font-size: 1.5rem; font-weight: 800; color: var(--text-primary); font-variant-numeric: tabular-nums; }
.fsrs-summary-lbl { margin-top: 0.2rem; font-size: 0.72rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.04em; }
.accent-red { color: var(--danger); }
.accent-yellow { color: var(--warning); }
.accent-green { color: var(--success); }

/* --- Activity heatmap --- */
.heatmap-wrap { margin-top: 0.5rem; }
.heatmap-head {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 0.55rem;
    font-size: 0.82rem;
    color: var(--text-secondary);
}
.heatmap-total { color: var(--text-muted); font-size: 0.76rem; }
.activity-heatmap {
    display: grid;
    grid-auto-flow: column;
    grid-template-rows: repeat(7, 1fr);
    grid-auto-columns: 1fr;
    gap: 3px;
    width: 100%;
}
.heat-cell {
    display: inline-block;
    width: 100%;
    aspect-ratio: 1 / 1;
    min-width: 9px;
    border-radius: 2px;
    background: var(--bg-input);
}
.heat-l0 { background: var(--bg-input); }
.heat-l1 { background: color-mix(in srgb, var(--success) 30%, var(--bg-input)); }
.heat-l2 { background: color-mix(in srgb, var(--success) 50%, var(--bg-input)); }
.heat-l3 { background: color-mix(in srgb, var(--success) 75%, var(--bg-input)); }
.heat-l4 { background: var(--success); }
.heatmap-legend {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 4px;
    margin-top: 0.55rem;
    font-size: 0.72rem;
    color: var(--text-muted);
}
.heatmap-legend .heat-cell { width: 11px; height: 11px; aspect-ratio: auto; }

/* --- Nav badge for due cards --- */
.nav-badge {
    margin-left: auto;
    min-width: 20px;
    height: 20px;
    padding: 0 6px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    background: var(--danger);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

/* --- FSRS chips + grade bar in revision queue --- */
.fsrs-chip {
    display: inline-flex;
    align-items: center;
    padding: 1px 8px;
    border-radius: 999px;
    background: var(--bg-input);
    border: 1px solid var(--border-card);
    font-size: 0.7rem;
    color: var(--text-secondary);
}
.fsrs-grade-bar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.75rem;
    padding-top: 0.85rem;
    border-top: 1px dashed var(--border-card);
}
.fsrs-grade-hint { font-size: 0.78rem; color: var(--text-muted); margin-right: 0.25rem; }
.fsrs-grade-btn {
    flex: 1 1 0;
    min-width: 84px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 0.5rem 0.6rem;
    border-radius: 10px;
    border: 1px solid var(--border-card);
    background: var(--bg-card);
    color: var(--text-primary);
    cursor: pointer;
    transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
}
.fsrs-grade-btn:hover { transform: translateY(-1px); box-shadow: var(--card-shadow); }
.fsrs-grade-label { font-weight: 700; font-size: 0.85rem; }
.fsrs-grade-iv { font-size: 0.72rem; color: var(--text-muted); font-variant-numeric: tabular-nums; }
.fsrs-again { border-color: var(--danger-border); }
.fsrs-again .fsrs-grade-label { color: var(--danger); }
.fsrs-hard .fsrs-grade-label { color: var(--warning); }
.fsrs-good .fsrs-grade-label { color: var(--primary); }
.fsrs-easy { border-color: var(--success-border); }
.fsrs-easy .fsrs-grade-label { color: var(--success); }

.revision-q-card-wrapper { transition: opacity 0.26s ease, transform 0.26s ease; }
.revision-q-card-wrapper.card-graded-out { opacity: 0; transform: translateX(24px); }

@media (max-width: 640px) {
    .fsrs-summary-grid { grid-template-columns: repeat(2, 1fr); }
    .gamification-panel { max-width: none; }
}

/* ============================================================
   DRILL-DOWN NAVIGATION (Database -> Subjects -> Sets -> Reader)
   Standard-QBank style focused full-width screens.
   ============================================================ */

/* Explorer is now a single full-width column; the old left tree is
   replaced by the Subjects/Topics grid screens, and the questions
   palette is an overlay drawer (see below) rather than a column. */
.explorer-sidebar { display: none !important; }
.explorer-layout { grid-template-columns: 1fr !important; }

/* Drill-down screens live inside .explorer-main */
.explorer-screen { display: none; }
.explorer-main.on-subjects, .explorer-main.on-topics { padding-top: 1.25rem; }

.screen-head {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    max-width: 1100px;
}
.screen-head-titles h2 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.15;
}
.screen-head-titles p {
    margin: 0.2rem 0 0;
    font-size: 0.85rem;
    color: var(--text-muted);
}
.screen-back-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.85rem;
    border-radius: 10px;
    border: 1px solid var(--border-card);
    background: var(--bg-card);
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    white-space: nowrap;
    transition: background 0.15s ease, color 0.15s ease, transform 0.12s ease;
}
.screen-back-btn:hover { background: var(--bg-card-hover); color: var(--text-primary); transform: translateX(-2px); }
.screen-back-btn i { width: 16px; height: 16px; }
.reader-back-btn { margin-right: 0.25rem; }

/* Responsive card grid */
.drill-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
    max-width: 1100px;
    padding-bottom: 2rem;
}
.drill-card {
    display: flex;
    align-items: center;
    gap: 0.9rem;
    text-align: left;
    padding: 1.1rem 1.2rem;
    border-radius: 16px;
    border: 1px solid var(--border-card);
    background: var(--bg-card);
    box-shadow: var(--card-shadow);
    cursor: pointer;
    transition: transform 0.15s var(--ease-glass, ease), border-color 0.15s ease, box-shadow 0.15s ease;
}
.drill-card:hover {
    transform: translateY(-3px);
    border-color: var(--primary);
    box-shadow: var(--glass-highlight, none), 0 12px 30px -12px var(--primary-glow, rgba(0,0,0,0.4));
}
.drill-card-icon {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    background: color-mix(in srgb, var(--primary) 16%, var(--bg-input));
    color: var(--primary);
}
.drill-card-icon.done { background: var(--success-bg, color-mix(in srgb, var(--success) 18%, var(--bg-input))); color: var(--success); }
.drill-card-icon i { width: 22px; height: 22px; }
.drill-card-accent .drill-card-icon { background: color-mix(in srgb, #ec4899 18%, var(--bg-input)); color: #ec4899; }
.drill-card-body { flex: 1; min-width: 0; }
.drill-card-title {
    font-weight: 700;
    color: var(--text-primary);
    font-size: 0.98rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.drill-card-meta { margin-top: 0.15rem; font-size: 0.78rem; color: var(--text-muted); }
.drill-progress {
    margin-top: 0.55rem;
    height: 6px;
    border-radius: 4px;
    background: var(--bg-input);
    overflow: hidden;
}
.drill-progress-bar {
    height: 100%;
    border-radius: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transition: width 0.4s ease;
}
.drill-card-pct {
    flex-shrink: 0;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-secondary);
    font-variant-numeric: tabular-nums;
}
.drill-card-arrow { flex-shrink: 0; width: 18px; height: 18px; color: var(--text-muted); }

/* Full-width reader: cap line length for readability but never squeeze */
.questions-stream { max-width: 1000px; margin: 0 auto; width: 100%; }

/* Questions palette as a right-side overlay drawer on desktop */
@media (min-width: 1025px) {
    .explorer-right-sidebar {
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        width: 340px;
        max-width: 85vw;
        z-index: 600;
        border-left: 1px solid var(--border-glass, var(--border-card));
        box-shadow: -16px 0 40px -20px rgba(0,0,0,0.6);
        transform: translateX(100%);
        transition: transform 0.32s var(--ease-glass, ease);
    }
    .explorer-right-sidebar.mobile-open { transform: translateX(0); }
}

@media (max-width: 700px) {
    .drill-grid { grid-template-columns: 1fr; }
    .screen-head-titles h2 { font-size: 1.25rem; }
}

/* ========================================================
   MISTAKE-HISTORY NOTE + HIDE-ANSWER TOGGLE
   ======================================================== */
.fsrs-chip-ok { color: var(--success); border-color: var(--success); }
.fsrs-chip-warn { color: var(--danger); border-color: var(--danger); }
.history-note {
    margin-top: 0.85rem;
    gap: 0.4rem;
    font-weight: 600;
}
.history-note-icon { font-size: 0.85em; }
.hide-answer-btn { order: -1; }

/* ========================================================
   SHAREABLE MODULES: select mode, floating bar, modals
   ======================================================== */
.question-card.select-mode-active { cursor: default; }
.question-card.selected-for-module {
    border-color: var(--primary);
    box-shadow: 0 0 0 2px var(--primary), var(--card-shadow);
}
.question-select-checkbox {
    display: inline-flex;
    align-items: center;
    margin-right: 0.6rem;
    cursor: pointer;
}
.question-select-checkbox input[type="checkbox"] {
    width: 19px;
    height: 19px;
    accent-color: var(--primary);
    cursor: pointer;
}

.module-select-bar {
    position: fixed;
    left: 50%;
    bottom: 1.5rem;
    transform: translateX(-50%);
    z-index: 850;
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.7rem 0.9rem 0.7rem 1.2rem;
    border-radius: 999px;
    background: var(--bg-sidebar, var(--bg-card));
    border: 1px solid var(--border-glass, var(--border-card));
    box-shadow: var(--glass-highlight, none), 0 20px 50px -15px rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(var(--glass-blur, 16px));
    -webkit-backdrop-filter: blur(var(--glass-blur, 16px));
    color: var(--text-primary);
    font-size: 0.88rem;
    font-weight: 600;
}
.module-select-bar.hidden { display: none; }
.module-select-actions { display: flex; align-items: center; gap: 0.5rem; }

.module-link-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.module-link-row input {
    flex: 1 1 auto;
    padding: 0.6rem 0.75rem;
    border-radius: 10px;
    border: 1px solid var(--border-input, var(--border-card));
    background: var(--bg-input);
    color: var(--text-primary);
    font-size: 0.82rem;
}

.module-list {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}
.module-list-empty { font-size: 0.85rem; color: var(--text-muted); }
.module-list-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    padding: 0.75rem 0.9rem;
    border-radius: 12px;
    background: var(--bg-input);
    border: 1px solid var(--border-card);
    flex-wrap: wrap;
}
.module-list-item-info { display: flex; flex-direction: column; gap: 0.2rem; min-width: 0; }
.module-list-item-name { font-weight: 700; color: var(--text-primary); }
.module-list-item-meta { font-size: 0.75rem; color: var(--text-muted); }
.module-list-item-actions { display: flex; gap: 0.4rem; flex-shrink: 0; }

@media (max-width: 700px) {
    .module-select-bar { left: 1rem; right: 1rem; transform: none; justify-content: space-between; }
}