/* ============================================
   USMLE QBANK — Complete Stylesheet
   ============================================ */

:root {
    --primary: #05BBC9;
    --primary-dark: #049DA9;
    --primary-light: #DFF6F8;
    --success: #8BC34A;
    --success-light: #EDF7E1;
    --error: #FF4343;
    --error-light: #FCE8E6;
    --warning: #F0D020;
    --warning-light: #FEF7E0;
    --accent-blue: #3852A4;
    --bg: #F5F6F9;
    --card: #ffffff;
    --sidebar-bg: #252D3E;
    --sidebar-hover: #2E3A50;
    --sidebar-active: rgba(5,187,201,0.18);
    --text: #333333;
    --text-secondary: #535F6B;
    --text-light: #80868b;
    --border: #D8D8D8;
    --border-light: #EAEBEE;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1), 0 6px 10px rgba(0,0,0,0.08);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --sidebar-width: 260px;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; }
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    display: flex;
    min-height: 100vh;
    min-height: 100dvh;
    overflow: hidden;
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #c1c1c1; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #a0a0a0; }

/* ===== SIDEBAR ===== */
#sidebar {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    background: var(--sidebar-bg);
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
    position: fixed;
    left: 0;
    top: 0;
    z-index: 100;
    transition: transform var(--transition);
}
.sidebar-logo {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 24px 20px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.logo-icon {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, #8BC34A, #7CB342);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    font-size: 22px;
    color: #fff;
    flex-shrink: 0;
}
.logo-text { display: flex; flex-direction: column; }
.logo-title { color: #fff; font-weight: 800; font-size: 18px; letter-spacing: 1px; }
.logo-subtitle { color: rgba(255,255,255,0.5); font-size: 12px; font-weight: 500; }

.sidebar-menu {
    flex: 1;
    padding: 16px 12px;
    overflow-y: auto;
}
.menu-item {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 12px 16px;
    color: rgba(255,255,255,0.65);
    text-decoration: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition);
    font-weight: 500;
    font-size: 14px;
    margin-bottom: 4px;
    user-select: none;
}
.menu-item:hover {
    background: var(--sidebar-hover);
    color: rgba(255,255,255,0.9);
}
.menu-item.active {
    background: var(--sidebar-active);
    color: #05BBC9;
    font-weight: 600;
    border-left: 3px solid #05BBC9;
}
.menu-item svg { opacity: 0.8; flex-shrink: 0; }
.menu-item.active svg { opacity: 1; }

.sidebar-footer {
    padding: 16px 20px;
    border-top: 1px solid rgba(255,255,255,0.08);
}
.sidebar-stats { display: flex; gap: 16px; }
.stat-mini {
    color: rgba(255,255,255,0.4);
    font-size: 12px;
    font-weight: 500;
}
.stat-mini span { color: rgba(255,255,255,0.8); font-weight: 700; }

/* ===== MAIN CONTENT ===== */
#main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    height: 100vh;
    height: 100dvh;
    overflow-y: auto;
    overflow-x: hidden;
}
.screen { display: none; padding: 32px; padding-bottom: 80px; min-height: 100vh; min-height: 100dvh; }
.screen.active { display: block; }

/* ===== COMMON COMPONENTS ===== */
.page-header {
    margin-bottom: 28px;
}
.page-header h1 {
    font-size: 28px;
    font-weight: 800;
    color: var(--text);
    margin-bottom: 4px;
}
.page-header p {
    color: var(--text-secondary);
    font-size: 15px;
}

.card {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 20px;
    border: 1px solid var(--border-light);
    transition: box-shadow var(--transition);
}
.card:hover { box-shadow: var(--shadow-md); }
.card-title {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    border-radius: var(--radius-sm);
    font-family: var(--font);
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all var(--transition);
    text-decoration: none;
    user-select: none;
}
.btn-primary {
    background: #05BBC9;
    color: #fff;
}
.btn-primary:hover {
    background: #049DA9;
    box-shadow: 0 4px 12px rgba(5,187,201,0.35);
    transform: translateY(-1px);
}
.btn-secondary {
    background: transparent;
    color: #05BBC9;
    border-color: #05BBC9;
}
.btn-secondary:hover {
    background: #DFF6F8;
}
.btn-success {
    background: #8BC34A;
    color: #fff;
}
.btn-success:hover {
    background: #7CB342;
    box-shadow: 0 4px 12px rgba(139,195,74,0.35);
}
.btn-danger {
    background: var(--error);
    color: #fff;
}
.btn-danger:hover { background: #c5221f; }
.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}
.btn-ghost:hover { background: #f5f5f5; color: var(--text); }
.btn-sm { padding: 6px 14px; font-size: 13px; }
.btn-lg { padding: 14px 32px; font-size: 16px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }

/* Grid */
.grid { display: grid; gap: 20px; }
.grid-2 { grid-template-columns: 1fr 1fr; }
.grid-3 { grid-template-columns: 1fr 1fr 1fr; }
.grid-4 { grid-template-columns: 1fr 1fr 1fr 1fr; }

/* ===== DASHBOARD ===== */
.stats-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 28px;
}
.stat-card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}
.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
}
.stat-card:nth-child(1)::before { background: var(--accent-blue); }
.stat-card:nth-child(2)::before { background: var(--success); }
.stat-card:nth-child(3)::before { background: var(--primary); }
.stat-card:nth-child(4)::before { background: var(--error); }
.stat-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.stat-label {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}
.stat-value {
    font-size: 32px;
    font-weight: 800;
    color: var(--text);
    line-height: 1.2;
}
.stat-sub {
    font-size: 13px;
    color: var(--text-light);
    margin-top: 4px;
}

/* Progress ring (dashboard) */
.progress-ring-container {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}
.progress-ring { position: relative; width: 160px; height: 160px; }
.progress-ring svg { transform: rotate(-90deg); }
.progress-ring circle {
    fill: none;
    stroke-width: 10;
    stroke-linecap: round;
}
.progress-ring .bg { stroke: #e8eaed; }
.progress-ring .fg { stroke: var(--success); transition: stroke-dashoffset 1s ease; }
.progress-ring .center-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}
.progress-ring .pct { font-size: 28px; font-weight: 800; color: var(--text); display: block; }
.progress-ring .pct-label { font-size: 12px; color: var(--text-secondary); }

/* ===== CREATE TEST ===== */
.create-container {
    max-width: 900px;
    margin: 0 auto;
}
.topic-selector {
    max-height: 500px;
    overflow-y: auto;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}
.topic-group {
    border-bottom: 1px solid var(--border-light);
}
.topic-group:last-child { border-bottom: none; }
.topic-group-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    cursor: pointer;
    background: #fafbfc;
    font-weight: 700;
    font-size: 14px;
    color: var(--text);
    user-select: none;
    transition: background var(--transition);
    border: none;
    width: 100%;
    text-align: left;
    font-family: var(--font);
}
.topic-group-header:hover { background: var(--primary-light); }
.topic-group-header .chevron {
    transition: transform var(--transition);
    color: var(--text-light);
    margin-left: auto;
}
.topic-group-header.expanded .chevron { transform: rotate(90deg); }
.topic-group-count {
    background: #DFF6F8;
    color: #05BBC9;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 700;
}
.topic-subtopics {
    display: none;
    padding: 4px 18px 12px 48px;
}
.topic-subtopics.open { display: block; }
.subtopic-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    transition: background var(--transition);
    font-size: 13px;
}
.subtopic-item:hover { background: #f5f5f5; }
.subtopic-item label { cursor: pointer; flex: 1; }
.subtopic-count {
    color: var(--text-light);
    font-size: 12px;
    font-weight: 600;
}

/* Checkbox custom */
.custom-check {
    width: 20px;
    height: 20px;
    border: 2px solid #c4c4c4;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition);
    flex-shrink: 0;
}
.custom-check.checked {
    background: #05BBC9;
    border-color: #05BBC9;
}
.custom-check.partial {
    background: #05BBC9;
    border-color: #05BBC9;
    opacity: 0.6;
}
.custom-check svg { display: none; }
.custom-check.checked svg,
.custom-check.partial svg { display: block; }

/* Mode selector (legacy) */
.mode-selector {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin: 16px 0;
}
.mode-card {
    border: 2px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition);
    background: var(--card);
}
.mode-card:hover { border-color: var(--primary); background: var(--primary-light); }
.mode-card.selected {
    border-color: var(--primary);
    background: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(26,115,232,0.15);
}
.mode-card .mode-icon { font-size: 32px; margin-bottom: 10px; }
.mode-card .mode-name { font-weight: 700; font-size: 15px; margin-bottom: 4px; }
.mode-card .mode-desc { font-size: 12px; color: var(--text-secondary); }

/* Mode toggle switches */
.mode-toggles {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin: 16px 0;
}
.mode-toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    background: var(--card);
    transition: border-color var(--transition), background var(--transition);
}
.mode-toggle-row:has(input:checked) {
    border-color: var(--primary);
    background: var(--primary-light);
}
.mode-toggle-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
}
.mode-toggle-label {
    font-weight: 700;
    font-size: 15px;
    color: var(--text);
}
.mode-toggle-desc {
    font-size: 12px;
    color: var(--text-secondary);
}
.toggle-switch {
    position: relative;
    display: inline-block;
    width: 52px;
    height: 28px;
    flex-shrink: 0;
}
.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}
.toggle-slider {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background: #ccc;
    border-radius: 28px;
    transition: 0.3s;
}
.toggle-slider::before {
    content: "";
    position: absolute;
    height: 22px;
    width: 22px;
    left: 3px;
    bottom: 3px;
    background: white;
    border-radius: 50%;
    transition: 0.3s;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.toggle-switch input:checked + .toggle-slider {
    background: #05BBC9;
}
.toggle-switch input:checked + .toggle-slider::before {
    transform: translateX(24px);
}
.toggle-switch input:focus + .toggle-slider {
    box-shadow: 0 0 0 3px rgba(5,187,201,0.15);
}

/* Question count input */
.q-count-section {
    display: flex;
    align-items: center;
    gap: 20px;
    margin: 20px 0;
}
.q-count-input {
    width: 100px;
    padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font);
    font-size: 18px;
    font-weight: 700;
    text-align: center;
    color: var(--text);
    transition: border-color var(--transition);
}
.q-count-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(26,115,232,0.1);
}
.q-count-slider {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 6px;
    border-radius: 3px;
    background: #e0e0e0;
    outline: none;
}
.q-count-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

/* Filter options */
.filter-row {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin: 16px 0;
}
.filter-chip {
    padding: 8px 18px;
    border-radius: 20px;
    border: 2px solid var(--border);
    font-family: var(--font);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
    background: var(--card);
    color: var(--text-secondary);
    user-select: none;
}
.filter-chip:hover { border-color: #05BBC9; color: #05BBC9; }
.filter-chip.active {
    background: #05BBC9;
    border-color: #05BBC9;
    color: #fff;
}

/* ===== TEST INTERFACE ===== */
#screen-test { padding: 0; padding-bottom: 0; }
#screen-test.active { display: flex; flex-direction: column; height: 100vh; height: 100dvh; min-height: 0; overflow: hidden; }

/* When test is active, prevent parent scroll */
#main-content:has(#screen-test.active) {
    overflow: hidden;
}

.test-top-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 24px;
    background: var(--card);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    z-index: 50;
    gap: 16px;
}
.test-top-left { display: flex; align-items: center; gap: 16px; }
.test-top-center { display: flex; align-items: center; gap: 12px; flex: 1; justify-content: center; }
.test-top-right { display: flex; align-items: center; gap: 10px; }

.test-timer {
    font-size: 20px;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    color: var(--text);
    background: #f5f5f5;
    padding: 6px 16px;
    border-radius: var(--radius-sm);
    min-width: 100px;
    text-align: center;
}
.test-timer.timed-active {
    background: #05BBC9;
    color: #fff;
    font-size: 22px;
    padding: 8px 20px;
}
.test-timer.warning { color: #333; background: var(--warning); }
.test-timer.danger { color: #fff; background: var(--error); animation: pulse 1s infinite; }

.test-progress-bar {
    height: 4px;
    background: #e8eaed;
    position: relative;
    flex: 1;
    max-width: 300px;
    border-radius: 2px;
}
.test-progress-bar .fill {
    height: 100%;
    background: #05BBC9;
    border-radius: 2px;
    transition: width 0.5s ease;
}
.test-question-counter {
    font-weight: 700;
    font-size: 14px;
    color: var(--text);
    white-space: nowrap;
}

.tool-btn {
    width: 38px;
    height: 38px;
    border: none;
    background: #f5f5f5;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    color: var(--text-secondary);
    font-size: 18px;
}
.tool-btn:hover { background: #e8eaed; color: var(--text); }
.tool-btn.active { background: var(--primary-light); color: var(--primary); }
.tool-btn.flagged { background: var(--warning-light); color: var(--warning); }

/* Question content area */
.test-body {
    display: flex;
    flex: 1;
    overflow: hidden;
    min-height: 0;
}
.question-panel {
    flex: 1;
    padding: 32px 40px;
    overflow-y: auto;
}
.question-stem {
    font-size: 16px;
    line-height: 1.85;
    color: var(--text);
    margin-bottom: 28px;
}
.question-id-badge {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    color: #6b7685;
    background: #f0f2f5;
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: 12px;
    letter-spacing: 0.3px;
    border: 1px solid #e0e4ea;
}
.question-stem p { margin-bottom: 16px; }
.question-stem table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    font-size: 14px;
}
.question-stem table td {
    padding: 10px 16px;
    border-bottom: 1px solid var(--border-light);
}
.question-stem table tr:nth-child(odd) { background: #fafbfc; }
.question-stem img {
    max-width: 100%;
    border-radius: var(--radius-sm);
    margin: 16px 0;
}
.question-stem .exhibit-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--primary-light);
    color: var(--primary);
    border: 1px solid var(--primary);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 600;
    font-size: 13px;
    margin: 12px 0;
    font-family: var(--font);
    transition: all var(--transition);
}
.question-stem .exhibit-btn:hover { background: var(--primary); color: #fff; }

/* Answer choices */
.choices-container { margin-bottom: 24px; }
.choice-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 18px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 10px;
    cursor: default;
    transition: all var(--transition);
    background: var(--card);
    position: relative;
}
.choice-item:hover {
    border-color: #ccd;
    background: #f7f9fb;
}
.choice-item.selected {
    border-color: #2196F3;
    background: #e8f0fe;
}
.choice-item.correct {
    border-color: var(--success) !important;
    background: var(--success-light) !important;
}
.choice-item.incorrect {
    border-color: var(--error) !important;
    background: var(--error-light) !important;
}
.choice-item.strikethrough .choice-text {
    text-decoration: line-through;
    color: var(--text-light);
}
.choice-item.strikethrough {
    opacity: 0.55;
}
.choice-item.disabled { pointer-events: none; }

/* Radio circle */
.choice-radio {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 2px solid #bbb;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    cursor: pointer;
    transition: all 0.15s ease;
    margin-top: 2px;
}
.choice-radio:hover {
    border-color: #2196F3;
}
.choice-radio-inner {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: transparent;
    transition: all 0.15s ease;
}
.choice-item.selected .choice-radio {
    border-color: #2196F3;
}
.choice-item.selected .choice-radio-inner {
    background: #2196F3;
}
.choice-item.correct .choice-radio {
    border-color: var(--success);
}
.choice-item.correct .choice-radio-inner {
    background: var(--success);
}
.choice-item.incorrect .choice-radio {
    border-color: var(--error);
}
.choice-item.incorrect .choice-radio-inner {
    background: var(--error);
}

.choice-letter {
    font-weight: 700;
    font-size: 15px;
    color: var(--text-secondary);
    flex-shrink: 0;
    padding-top: 2px;
    min-width: 22px;
}
.choice-item.selected .choice-letter {
    color: #2196F3;
    font-weight: 800;
}
.choice-item.correct .choice-letter {
    color: var(--success);
}
.choice-item.incorrect .choice-letter {
    color: var(--error);
}
.choice-text { flex: 1; font-size: 15px; line-height: 1.6; padding-top: 2px; cursor: pointer; }
.choice-text:hover { color: var(--text-light); }
.choice-percent {
    font-size: 13px;
    font-weight: 700;
    color: var(--text-light);
    padding-top: 8px;
    min-width: 40px;
    text-align: right;
    display: none;
}
.choice-item.show-stats .choice-percent { display: block; }

.choice-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 3px;
    background: #05BBC9;
    border-radius: 0 0 var(--radius) var(--radius);
    transition: width 0.6s ease;
    opacity: 0;
}
.choice-item.show-stats .choice-bar { opacity: 1; }

/* Explanation panel */
.explanation-panel {
    margin-top: 24px;
    padding: 28px;
    background: linear-gradient(135deg, #f8f9fa, #fff);
    border-radius: var(--radius);
    border-left: 4px solid #05BBC9;
    animation: slideUp 0.3s ease;
}
.explanation-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-light);
}
.explanation-result {
    font-weight: 800;
    font-size: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.explanation-result.correct-result { color: #8BC34A; }
.explanation-result.incorrect-result { color: #FF4343; }
.explanation-stats {
    display: flex;
    gap: 20px;
    margin-left: auto;
    font-size: 13px;
    color: var(--text-secondary);
}
.explanation-stats span { font-weight: 700; }
.explanation-content {
    font-size: 15px;
    line-height: 1.85;
    color: var(--text);
}
.explanation-content p { margin-bottom: 14px; }
.explanation-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
}
.explanation-content table td {
    padding: 10px 16px;
    border-bottom: 1px solid var(--border-light);
    font-size: 14px;
    vertical-align: top;
}
.explanation-content table tr:nth-child(odd) { background: #fafbfc; }
.explanation-content img {
    max-width: 100%;
    border-radius: var(--radius-sm);
    margin: 16px 0;
}
.explanation-content .edu-objective {
    background: #DFF6F8;
    padding: 16px 20px;
    border-radius: var(--radius-sm);
    margin-top: 16px;
    border-left: 3px solid #05BBC9;
}
.explanation-content .edu-objective strong {
    display: block;
    margin-bottom: 6px;
    color: #05BBC9;
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Bottom navigation bar */
.test-bottom-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 24px;
    background: var(--card);
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}
.test-bottom-left,
.test-bottom-center,
.test-bottom-right { display: flex; align-items: center; gap: 10px; }
.test-bottom-center { flex: 1; justify-content: center; }

/* Bottom bar action buttons (End Block, Suspend) */
.btn-end-block {
    background: var(--error);
    color: #fff;
    padding: 8px 18px;
    border-radius: var(--radius-sm);
    font-family: var(--font);
    font-weight: 600;
    font-size: 13px;
    border: none;
    cursor: pointer;
    transition: all var(--transition);
}
.btn-end-block:hover { background: #E03030; }
.btn-suspend {
    background: var(--warning);
    color: #333;
    padding: 8px 18px;
    border-radius: var(--radius-sm);
    font-family: var(--font);
    font-weight: 600;
    font-size: 13px;
    border: none;
    cursor: pointer;
    transition: all var(--transition);
}
.btn-suspend:hover { background: #D9BC1C; }

/* Question navigator drawer */
/* Navigator overlay backdrop */
.q-navigator-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.45);
    z-index: 199;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}
.q-navigator-overlay.open {
    opacity: 1;
    pointer-events: auto;
}

/* Navigator drawer */
.q-navigator {
    position: fixed;
    right: 0;
    top: 0;
    width: 340px;
    height: 100vh;
    background: var(--card);
    box-shadow: -4px 0 24px rgba(0,0,0,0.2);
    z-index: 200;
    display: flex;
    flex-direction: column;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.q-navigator.open { transform: translateX(0); }
.q-navigator-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.q-navigator-header h3 { font-size: 16px; font-weight: 700; }
.q-navigator-body {
    flex: 1;
    padding: 20px 24px;
    overflow-y: auto;
}
.q-navigator-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}
.q-nav-item {
    width: 100%;
    aspect-ratio: 1;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 13px;
    cursor: pointer;
    transition: all var(--transition);
    background: var(--card);
    font-family: var(--font);
}
.q-nav-item:hover { border-color: #05BBC9; }
.q-nav-item.current { border-color: #05BBC9; background: #DFF6F8; color: #05BBC9; }
.q-nav-item.answered { background: #e8eaed; }
.q-nav-item.correct-nav { background: #EDF7E1; border-color: #8BC34A; color: #7CB342; }
.q-nav-item.incorrect-nav { background: var(--error-light); border-color: var(--error); color: var(--error); }
.q-nav-item.flagged-nav { position: relative; }
.q-nav-item.flagged-nav::after {
    content: '⚑';
    position: absolute;
    top: -2px;
    right: -2px;
    font-size: 10px;
    color: var(--warning);
}

.q-navigator-legend {
    padding: 16px 24px;
    border-top: 1px solid var(--border);
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    font-size: 12px;
    color: var(--text-secondary);
}
.legend-item { display: flex; align-items: center; gap: 6px; }
.legend-dot {
    width: 14px;
    height: 14px;
    border-radius: 4px;
    border: 2px solid;
}

/* ===== RESULTS SCREEN ===== */
.results-container { max-width: 960px; margin: 0 auto; }

/* Hero section with donut chart */
.results-hero {
    display: flex;
    align-items: center;
    gap: 40px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 40px;
    margin-bottom: 24px;
}
.results-hero-left {
    flex-shrink: 0;
}
.results-donut {
    width: 200px;
    height: 200px;
}
.results-donut .donut-pct {
    font-size: 36px;
    font-weight: 900;
    fill: var(--text);
}
.results-donut .donut-label {
    font-size: 14px;
    font-weight: 600;
    fill: var(--text-secondary);
}
.results-donut circle {
    transition: stroke-dasharray 1s ease, stroke-dashoffset 1s ease;
}
.results-hero-right {
    flex: 1;
    min-width: 0;
}
.results-title {
    font-size: 26px;
    font-weight: 800;
    color: var(--text);
    margin-bottom: 4px;
}
.results-mode {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 20px;
}
.results-stats-row {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 24px;
}
.results-mini-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 12px 18px;
    border-radius: var(--radius-sm);
    min-width: 80px;
}
.results-mini-stat .stat-num {
    font-size: 22px;
    font-weight: 800;
    line-height: 1.2;
}
.results-mini-stat .stat-txt {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    margin-top: 2px;
}
.correct-stat { background: var(--success-light); }
.correct-stat .stat-num { color: var(--success); }
.incorrect-stat { background: var(--error-light); }
.incorrect-stat .stat-num { color: var(--error); }
.omitted-stat { background: #f0f2f5; }
.omitted-stat .stat-num { color: var(--text-light); }
.time-stat { background: var(--primary-light); }
.time-stat .stat-num { color: var(--primary); }

.results-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}
.results-actions .btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

/* Questions card */
.results-questions-card {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}
.results-questions-header {
    padding: 20px 24px 0;
}
.results-questions-header h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
}
.results-tabs {
    margin-bottom: 0;
}

.results-subtitle { color: var(--text-secondary); font-size: 16px; }

.results-summary-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin: 24px 0;
}
.result-stat-card {
    text-align: center;
    padding: 20px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.result-stat-card .val {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 4px;
}
.result-stat-card .lbl { font-size: 13px; color: var(--text-secondary); }
.result-stat-card.green .val { color: var(--success); }
.result-stat-card.red .val { color: var(--error); }
.result-stat-card.blue .val { color: var(--primary); }

/* Results question list */
.results-question-list { margin-top: 24px; }
.results-q-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 20px;
    border-bottom: 1px solid var(--border-light);
    cursor: pointer;
    transition: background var(--transition);
}
.results-q-item:hover { background: #fafbfc; }
.results-q-icon {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    flex-shrink: 0;
}
.results-q-icon.correct-icon { background: var(--success-light); color: var(--success); }
.results-q-icon.incorrect-icon { background: var(--error-light); color: var(--error); }
.results-q-icon.skipped-icon { background: #f5f5f5; color: var(--text-light); }
.results-q-info { flex: 1; }
.results-q-info .q-num { font-weight: 700; font-size: 14px; }
.results-q-info .q-topic { font-size: 12px; color: var(--text-secondary); }
.results-q-answer { font-size: 13px; font-weight: 600; }
.results-q-time { font-size: 13px; color: var(--text-light); min-width: 60px; text-align: right; }

/* ===== PERFORMANCE ===== */
.perf-chart-container {
    background: var(--card);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
}
.perf-bar-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 0;
    border-bottom: 1px solid var(--border-light);
}
.perf-bar-label {
    width: 250px;
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
    flex-shrink: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.perf-bar-track {
    flex: 1;
    height: 24px;
    background: #f0f0f0;
    border-radius: 12px;
    overflow: hidden;
    position: relative;
}
.perf-bar-fill {
    height: 100%;
    border-radius: 12px;
    transition: width 0.8s ease;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 10px;
    font-size: 12px;
    font-weight: 700;
    color: #fff;
    min-width: fit-content;
}
.perf-bar-fill.good { background: linear-gradient(90deg, #8BC34A, #7CB342); }
.perf-bar-fill.medium { background: linear-gradient(90deg, #fbbc05, #f9ab00); }
.perf-bar-fill.poor { background: linear-gradient(90deg, #ea4335, #d93025); }
.perf-bar-value {
    min-width: 70px;
    text-align: right;
    font-size: 13px;
    font-weight: 700;
    color: var(--text);
}

/* ===== SEARCH ===== */
.search-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--card);
    padding: 12px 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
    border: 2px solid transparent;
    transition: border-color var(--transition);
}
.search-bar:focus-within { border-color: var(--primary); }
.search-bar input {
    flex: 1;
    border: none;
    outline: none;
    font-family: var(--font);
    font-size: 15px;
    color: var(--text);
    background: transparent;
}
.search-bar svg { color: var(--text-light); }
.search-results-list { max-height: 600px; overflow-y: auto; }
.search-result-item {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-light);
    cursor: pointer;
    transition: background var(--transition);
}
.search-result-item:hover { background: #fafbfc; }

/* ===== PREVIOUS TESTS ===== */
.test-history-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 20px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 12px;
    cursor: pointer;
    transition: all var(--transition);
    border: 1px solid var(--border-light);
}
.test-history-item:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.test-history-score {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 800;
    flex-shrink: 0;
}
.test-history-info { flex: 1; }
.test-history-info .th-title { font-weight: 700; font-size: 15px; margin-bottom: 4px; }
.test-history-info .th-meta { font-size: 13px; color: var(--text-secondary); }
.test-history-actions { display: flex; gap: 8px; }\n\n/* Suspended test badge */\n.th-status-badge {\n    display: inline-flex;\n    align-items: center;\n    padding: 2px 10px;\n    border-radius: 12px;\n    font-size: 11px;\n    font-weight: 700;\n    text-transform: uppercase;\n    letter-spacing: 0.5px;\n}\n.th-status-badge.suspended {\n    background: var(--warning-light);\n    color: #B8960A;\n}\n.th-status-badge.completed {\n    background: #EDF7E1;\n    color: #7CB342;\n}

/* ===== NOTEBOOK ===== */
.notebook-card {
    padding: 20px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 12px;
    border-left: 4px solid var(--primary);
}
.notebook-card .nb-qid { font-weight: 700; color: var(--primary); margin-bottom: 6px; }
.notebook-card .nb-text { font-size: 14px; color: var(--text); white-space: pre-wrap; }
.notebook-card .nb-date { font-size: 12px; color: var(--text-light); margin-top: 8px; }

/* ===== MODALS ===== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.2s ease;
}
.modal-content {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    max-height: 85vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: slideUp 0.3s ease;
}
.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
}
.modal-header h2 { font-size: 18px; font-weight: 700; }
.modal-close {
    width: 36px;
    height: 36px;
    border: none;
    background: #f5f5f5;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    color: var(--text-secondary);
}
.modal-close:hover { background: #e8eaed; color: var(--text); }

.lab-modal-content { width: 700px; max-width: 95vw; }
.lab-body {
    padding: 24px;
    overflow-y: auto;
    max-height: 70vh;
    font-size: 14px;
    line-height: 1.7;
}
.lab-section { margin-bottom: 24px; }
.lab-section h3 {
    font-size: 15px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 10px;
    padding-bottom: 6px;
    border-bottom: 2px solid var(--primary-light);
}
.lab-section table { width: 100%; border-collapse: collapse; }
.lab-section td {
    padding: 6px 12px;
    border-bottom: 1px solid var(--border-light);
    font-size: 13px;
}
.lab-section td:first-child { font-weight: 600; width: 50%; }

.calc-modal-content { width: 320px; }
.calc-body { padding: 20px; }
#calc-display {
    width: 100%;
    padding: 14px;
    font-size: 24px;
    font-weight: 700;
    text-align: right;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font);
    margin-bottom: 12px;
    color: var(--text);
    background: #fafbfc;
}
.calc-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
}
.calc-grid button {
    padding: 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font);
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    background: var(--card);
    transition: all var(--transition);
}
.calc-grid button:hover { background: #f5f5f5; }
.calc-op { color: var(--primary); font-weight: 700; }
.calc-eq { background: var(--primary) !important; color: #fff !important; }
.calc-eq:hover { background: var(--primary-dark) !important; }
.calc-clear { background: var(--error-light) !important; color: var(--error) !important; font-size: 14px !important; }

.notes-modal-content { width: 500px; max-width: 95vw; }
.notes-body { padding: 24px; }
#notes-textarea {
    width: 100%;
    min-height: 200px;
    padding: 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font);
    font-size: 14px;
    line-height: 1.6;
    resize: vertical;
    color: var(--text);
    transition: border-color var(--transition);
}
#notes-textarea:focus {
    outline: none;
    border-color: var(--primary);
}

/* Highlighted text */
.text-highlighted {
    background-color: #ffeb3b !important;
    border-radius: 2px;
    padding: 0 1px;
}
.highlighter-mode-active {
    cursor: crosshair !important;
}

/* ===== ANIMATIONS ===== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}
@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

/* ===== EMPTY STATE ===== */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-light);
}
.empty-state .empty-icon { font-size: 48px; margin-bottom: 16px; opacity: 0.5; }
.empty-state h3 { font-size: 18px; color: var(--text-secondary); margin-bottom: 8px; }
.empty-state p { font-size: 14px; max-width: 400px; margin: 0 auto; }

/* ===== LOGIN SCREEN ===== */
.login-screen {
    display: none;
    position: fixed;
    inset: 0;
    background: linear-gradient(135deg, #1a2233 0%, #252D3E 40%, #2a3a52 100%);
    z-index: 10000;
    align-items: center;
    justify-content: center;
    padding: 20px;
}
.login-screen::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 40%, rgba(5,187,201,0.08) 0%, transparent 50%),
                radial-gradient(circle at 70% 60%, rgba(56,82,164,0.06) 0%, transparent 50%);
    pointer-events: none;
}
.login-card {
    background: #fff;
    border-radius: 20px;
    box-shadow: 0 25px 80px rgba(0,0,0,0.35), 0 0 0 1px rgba(255,255,255,0.05);
    padding: 44px 40px 36px;
    width: 100%;
    max-width: 420px;
    position: relative;
    animation: loginSlideIn 0.4s ease-out;
}
@keyframes loginSlideIn {
    from { opacity: 0; transform: translateY(20px) scale(0.98); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}
.login-logo {
    text-align: center;
    margin-bottom: 36px;
}
.logo-icon-wrap {
    display: inline-block;
    margin-bottom: 16px;
    filter: drop-shadow(0 4px 12px rgba(5,187,201,0.3));
}
.login-logo h1 {
    font-size: 26px;
    font-weight: 800;
    color: #1a2233;
    margin-bottom: 4px;
    letter-spacing: -0.3px;
}
.login-subtitle {
    color: #8b95a5;
    font-size: 15px;
    font-weight: 500;
}
.login-field {
    margin-bottom: 20px;
}
.login-field label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    font-weight: 600;
    color: #6b7685;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.login-field label svg { opacity: 0.5; }
.login-field input {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #e8ecf1;
    border-radius: 10px;
    font-family: var(--font);
    font-size: 15px;
    transition: all 0.2s ease;
    background: #f8f9fb;
    color: var(--text);
}
.login-field input:focus {
    outline: none;
    border-color: #05BBC9;
    background: #fff;
    box-shadow: 0 0 0 4px rgba(5,187,201,0.1);
}
.login-field input::placeholder { color: #b5bdc8; }
.login-error {
    color: #FF4343;
    font-size: 13px;
    font-weight: 600;
    min-height: 22px;
    margin-bottom: 6px;
    display: flex;
    align-items: center;
    gap: 4px;
}
.login-btn {
    width: 100%;
    padding: 14px;
    font-size: 15px;
    font-weight: 700;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.2s ease;
}
.login-btn:not(.login-btn-outline) {
    box-shadow: 0 4px 14px rgba(5,187,201,0.3);
}
.login-btn:not(.login-btn-outline):hover {
    box-shadow: 0 6px 20px rgba(5,187,201,0.4);
    transform: translateY(-1px);
}
.login-btn-outline {
    background: transparent;
    border: 2px solid #e0e4ea;
    color: #6b7685;
}
.login-btn-outline:hover {
    border-color: #05BBC9;
    color: #05BBC9;
    background: rgba(5,187,201,0.04);
}
.login-divider {
    text-align: center;
    margin: 18px 0;
    position: relative;
    color: #b5bdc8;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.login-divider::before,
.login-divider::after {
    content: '';
    position: absolute;
    top: 50%;
    width: calc(50% - 20px);
    height: 1px;
    background: #e8ecf1;
}
.login-divider::before { left: 0; }
.login-divider::after { right: 0; }
.login-footer-text {
    text-align: center;
    margin-top: 20px;
    font-size: 12px;
    color: #a3acb9;
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}
.login-footer-text::before {
    content: '☁';
    font-size: 14px;
}

/* Sidebar user & logout */
.sidebar-user {
    display: flex;
    align-items: center;
    gap: 8px;
    color: rgba(255,255,255,0.7);
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 10px;
    text-transform: capitalize;
}
.sidebar-user svg { opacity: 0.6; }
.sidebar-logout {
    width: 100%;
    margin-top: 10px;
    color: rgba(255,255,255,0.5);
    border-color: rgba(255,255,255,0.15);
    font-size: 12px;
    padding: 8px 12px;
}
.sidebar-logout:hover {
    color: rgba(255,255,255,0.9);
    background: rgba(255,255,255,0.08);
}

/* ===== HAMBURGER / MOBILE SIDEBAR ===== */
.hamburger-btn {
    display: none;
    position: fixed;
    top: 12px;
    left: 12px;
    z-index: 101;
    width: 44px;
    height: 44px;
    border: none;
    background: var(--sidebar-bg);
    color: #fff;
    border-radius: var(--radius-sm);
    cursor: pointer;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
}
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.45);
    z-index: 99;
    opacity: 0;
    transition: opacity 0.3s ease;
}
.sidebar-overlay.open {
    opacity: 1;
}

/* App container flex layout */
#app-container {
    display: flex;
    min-height: 100vh;
    width: 100%;
}

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

/* Tablet */
@media (max-width: 1024px) {
    .stats-row { grid-template-columns: repeat(2, 1fr); }
    .results-summary-grid { grid-template-columns: repeat(2, 1fr); }
    .results-hero { flex-direction: column; padding: 28px; gap: 24px; text-align: center; }
    .results-donut { width: 160px; height: 160px; }
    .results-stats-row { justify-content: center; }
    .results-actions { justify-content: center; }
    .grid-3, .grid-4 { grid-template-columns: 1fr 1fr; }
    .test-top-center { display: none; }
}

/* Mobile */
@media (max-width: 768px) {
    /* Sidebar as drawer */
    #sidebar {
        transform: translateX(-100%);
        z-index: 200;
    }
    #sidebar.open { transform: translateX(0); }

    .hamburger-btn { display: flex; }
    .sidebar-overlay { display: block; pointer-events: none; }
    .sidebar-overlay.open { pointer-events: auto; }

    #main-content {
        margin-left: 0;
        width: 100%;
    }

    .screen { padding: 16px; padding-top: 64px; padding-bottom: 100px; min-height: 100vh; min-height: 100dvh; }

    /* Typography */
    .page-header h1 { font-size: 22px; }
    .page-header p { font-size: 13px; }

    /* Stats */
    .stats-row { grid-template-columns: 1fr; }
    .stat-card { padding: 16px; }
    .stat-value { font-size: 28px; }

    /* Cards */
    .card { padding: 16px; margin-bottom: 14px; }
    .card-title { font-size: 15px; margin-bottom: 12px; }

    /* Create test */
    .mode-selector { grid-template-columns: 1fr; }
    .topic-group-header { padding: 12px 14px; font-size: 13px; }

    /* Test screen */
    .test-top-bar { padding: 8px 12px; gap: 8px; }
    .test-top-left { gap: 8px; }
    .test-top-right { gap: 4px; }
    .test-top-center { display: none; }
    .test-question-counter { font-size: 12px; }

    .tool-btn { width: 34px; height: 34px; font-size: 15px; }
    .font-size-controls { display: none; }

    .question-panel {
        padding: 16px;
    }
    .question-stem { font-size: 15px; line-height: 1.7; margin-bottom: 20px; }

    /* Choices */
    .choice-item { padding: 12px 14px; font-size: 14px; gap: 10px; }
    .choice-letter { width: 30px; height: 30px; font-size: 12px; min-width: 30px; }

    /* Bottom bar */
    .test-bottom-bar { padding: 8px 12px; gap: 6px; }
    .test-bottom-left .btn,
    .test-bottom-right .btn { padding: 8px 12px; font-size: 12px; }
    .test-bottom-center .btn { padding: 10px 20px; }
    .btn-end-block, .btn-suspend { padding: 6px 12px; font-size: 11px; }

    /* Navigator */
    .q-navigator { width: 280px; }
    .q-navigator-grid { grid-template-columns: repeat(5, 1fr); gap: 6px; }
    .q-nav-item { font-size: 11px; }

    /* Results */
    .results-summary-grid { grid-template-columns: 1fr; }
    .results-questions-grid { grid-template-columns: repeat(6, 1fr); }
    .results-hero { padding: 20px; gap: 16px; }
    .results-donut { width: 140px; height: 140px; }
    .results-title { font-size: 20px; }
    .results-mini-stat { padding: 8px 12px; min-width: 65px; }
    .results-mini-stat .stat-num { font-size: 18px; }
    .results-tabs { overflow-x: auto; flex-wrap: nowrap; }
    .results-tabs .tab { white-space: nowrap; padding: 10px 14px; font-size: 12px; }

    /* Previous tests */
    .test-history-item { flex-direction: column; align-items: flex-start; gap: 10px; }
    .test-history-score { align-self: flex-start; }

    /* Explanation */
    .explanation-panel { padding: 16px; }

    /* Modals */
    .modal-content { width: 95vw; max-width: 95vw; margin: 10px; }
    .lab-modal-content { width: 95vw; max-height: 85vh; }
    .confirm-box { margin: 16px; padding: 24px; max-width: calc(100vw - 32px); }

    /* Dashboard chart */
    .progress-ring-container svg { width: 120px; height: 120px; }

    /* Buttons general */
    .btn { padding: 10px 18px; font-size: 13px; }
    .btn-sm { padding: 6px 12px; font-size: 12px; }

    /* Tables */
    .topic-perf-table { font-size: 12px; }
    .topic-perf-table th, .topic-perf-table td { padding: 8px 10px; }

    /* Tabs */
    .tab { padding: 10px 16px; font-size: 13px; }

    /* Search */
    .search-input-wrap input { font-size: 14px; }
}

/* Small phones */
@media (max-width: 480px) {
    .screen { padding: 12px; padding-top: 60px; }

    .login-card { padding: 32px 24px 28px; border-radius: 16px; }
    .login-logo h1 { font-size: 22px; }
    .login-logo { margin-bottom: 28px; }
    .logo-icon-wrap svg { width: 52px; height: 52px; }

    .stats-row { gap: 10px; }
    .stat-card { padding: 14px; }
    .stat-value { font-size: 24px; }

    .results-questions-grid { grid-template-columns: repeat(5, 1fr); }

    .question-panel { padding: 12px; }
    .question-stem { font-size: 14px; }

    .choice-item { padding: 10px 12px; }

    .test-bottom-bar {
        flex-wrap: wrap;
        gap: 4px;
    }
    .test-bottom-left,
    .test-bottom-right { flex: 1; min-width: auto; }
    .test-bottom-center { flex: 0 0 100%; order: -1; }

    .q-navigator { width: 100%; }
    .q-navigator-grid { grid-template-columns: repeat(6, 1fr); }
}

/* ===== FONT SIZE CONTROL ===== */
.font-size-controls {
    display: flex;
    align-items: center;
    gap: 4px;
}
.font-btn {
    width: 30px;
    height: 30px;
    border: 1px solid var(--border);
    border-radius: 4px;
    background: var(--card);
    cursor: pointer;
    font-size: 14px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    font-family: var(--font);
    color: var(--text-secondary);
}
.font-btn:hover { background: #f5f5f5; color: var(--text); }

/* ===== EXHIBITS / Image viewer ===== */
.exhibit-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.85);
    z-index: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 16px;
}
.exhibit-overlay img {
    max-width: 90vw;
    max-height: 80vh;
    border-radius: var(--radius-sm);
    box-shadow: 0 10px 40px rgba(0,0,0,0.3);
}
.exhibit-controls {
    display: flex;
    gap: 8px;
}
.exhibit-controls button {
    padding: 8px 16px;
    border: none;
    border-radius: var(--radius-sm);
    background: rgba(255,255,255,0.2);
    color: #fff;
    cursor: pointer;
    font-family: var(--font);
    font-weight: 600;
    transition: background 0.2s;
}
.exhibit-controls button:hover { background: rgba(255,255,255,0.3); }

/* ===== CONFIRM DIALOG ===== */
.confirm-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 700;
    display: flex;
    align-items: center;
    justify-content: center;
}
.confirm-box {
    background: var(--card);
    padding: 32px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    max-width: 420px;
    text-align: center;
}
.confirm-box h3 { margin-bottom: 12px; font-size: 18px; }
.confirm-box p { margin-bottom: 24px; color: var(--text-secondary); font-size: 14px; }
.confirm-box .btn-row { display: flex; gap: 12px; justify-content: center; }

/* ===== TABS ===== */
.tabs {
    display: flex;
    gap: 0;
    border-bottom: 2px solid var(--border);
    margin-bottom: 20px;
}
.tab {
    padding: 12px 24px;
    font-family: var(--font);
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    border: none;
    background: none;
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
    transition: all var(--transition);
}
.tab:hover { color: var(--text); }
.tab.active { color: var(--primary); border-bottom-color: var(--primary); }

/* ===== LOADING ===== */
.loading-spinner {
    display: inline-block;
    width: 24px;
    height: 24px;
    border: 3px solid #e0e0e0;
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.loading-page {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 300px;
    gap: 12px;
    color: var(--text-secondary);
    font-size: 15px;
}

/* ===== TOOLTIP ===== */
[data-tooltip] {
    position: relative;
}
[data-tooltip]:hover::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: #333;
    color: #fff;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 12px;
    white-space: nowrap;
    z-index: 100;
    pointer-events: none;
}

/* ===== BADGE ===== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 700;
}
.badge-blue { background: var(--primary-light); color: var(--primary); }
.badge-green { background: var(--success-light); color: var(--success); }
.badge-red { background: var(--error-light); color: var(--error); }
.badge-yellow { background: var(--warning-light); color: var(--warning); }

/* ===== TOPIC PERFORMANCE TABLE ===== */
.topic-perf-table {
    width: 100%;
    border-collapse: collapse;
}
.topic-perf-table th {
    text-align: left;
    padding: 12px 16px;
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border);
}
.topic-perf-table td {
    padding: 12px 16px;
    font-size: 14px;
    border-bottom: 1px solid var(--border-light);
}
.topic-perf-table tr:hover td { background: #fafbfc; }

/* ===== UPGRADE BUTTON (small) ===== */
.page-header-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}
.upgrade-btn-small {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: linear-gradient(135deg, #05BBC9, #3852A4);
    color: #fff;
    border: none;
    padding: 7px 16px;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 700;
    cursor: pointer;
    white-space: nowrap;
    transition: transform 0.15s, box-shadow 0.15s;
}
.upgrade-btn-small:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(5,187,201,0.35);
}

/* ===== PAYWALL MODAL ===== */
.paywall-modal-content {
    max-width: 440px;
    text-align: center;
    padding: 40px 32px;
    border-radius: 16px;
    position: relative;
    animation: paywallSlideIn 0.3s ease;
}
@keyframes paywallSlideIn {
    from { opacity: 0; transform: translateY(20px) scale(0.95); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}
.paywall-icon {
    margin-bottom: 16px;
}
.paywall-title {
    font-size: 24px;
    font-weight: 800;
    color: var(--text-primary);
    margin: 0 0 8px;
}
.paywall-subtitle {
    font-size: 15px;
    color: var(--text-secondary);
    margin: 0 0 24px;
    line-height: 1.5;
}
.paywall-features {
    text-align: left;
    margin: 0 auto 24px;
    max-width: 320px;
}
.paywall-feature {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
    font-size: 14px;
    color: var(--text-primary);
}
.paywall-price {
    margin-bottom: 20px;
}
.paywall-amount {
    font-size: 48px;
    font-weight: 900;
    color: var(--accent);
    line-height: 1;
}
.paywall-period {
    display: block;
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 4px;
}
.paywall-btn {
    width: 100%;
    padding: 16px 24px;
    font-size: 18px;
    font-weight: 700;
    background: linear-gradient(135deg, #05BBC9, #3852A4);
    color: #fff;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: transform 0.15s, box-shadow 0.15s;
}
.paywall-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(5,187,201,0.35);
}
.paywall-btn:active {
    transform: translateY(0);
}
.paywall-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}
.paywall-secure {
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 16px;
}

/* Payment Success Toast */
.payment-toast {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: #1b5e20;
    color: #fff;
    padding: 14px 28px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 15px;
    font-weight: 600;
    z-index: 10000;
    box-shadow: 0 8px 30px rgba(0,0,0,0.3);
    animation: toastIn 0.4s ease;
}
@keyframes toastIn {
    from { opacity: 0; transform: translateX(-50%) translateY(-20px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* ===== ADMIN DASHBOARD ===== */
.menu-item-admin {
    border-top: 1px solid rgba(255,255,255,0.1);
    margin-top: 8px;
    padding-top: 12px !important;
}
.menu-item-admin svg { color: #ff9800; }
.menu-item-admin.active,
.menu-item-admin:hover {
    background: rgba(255,152,0,0.15) !important;
    color: #ff9800 !important;
}
.admin-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}
.admin-stat-card {
    background: var(--card-bg, #1e2636);
    border-radius: 12px;
    padding: 20px;
    text-align: center;
    border: 1px solid rgba(255,255,255,0.06);
}
.admin-stat-number {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary, #fff);
}
.admin-stat-label {
    font-size: 13px;
    color: var(--text-secondary, #8899aa);
    margin-top: 4px;
}
.admin-stat-active .admin-stat-number { color: #4caf50; }
.admin-stat-paid .admin-stat-number { color: #05bbc9; }
.admin-table-wrap {
    overflow-x: auto;
    background: var(--card-bg, #1e2636);
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.06);
}
.admin-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
    white-space: nowrap;
}
.admin-table th {
    background: rgba(255,255,255,0.04);
    padding: 12px 14px;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary, #8899aa);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    position: sticky;
    top: 0;
}
.admin-table td {
    padding: 10px 14px;
    border-top: 1px solid rgba(255,255,255,0.04);
    color: var(--text-primary, #fff);
}
.admin-table tbody tr:hover {
    background: rgba(255,255,255,0.03);
}
.admin-status-active {
    color: #4caf50;
    font-weight: 600;
}
.admin-status-active::before {
    content: '';
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #4caf50;
    margin-right: 6px;
}
.admin-status-inactive {
    color: var(--text-secondary, #8899aa);
}
.admin-status-inactive::before {
    content: '';
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--text-secondary, #8899aa);
    margin-right: 6px;
}
.admin-badge-paid {
    background: rgba(5,187,201,0.15);
    color: #05bbc9;
    padding: 3px 8px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 700;
}
.admin-badge-free {
    background: rgba(255,255,255,0.06);
    color: var(--text-secondary, #8899aa);
    padding: 3px 8px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 700;
}
.admin-loading, .admin-error {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary, #8899aa);
    font-size: 15px;
}
.admin-error { color: #ff4343; }

/* ===== RESET MODAL ===== */
.reset-modal-content {
    max-width: 440px;
    text-align: center;
    padding: 36px 32px;
}
.reset-modal-icon {
    margin-bottom: 16px;
}
.reset-modal-title {
    font-size: 22px;
    font-weight: 700;
    color: #FF4343;
    margin-bottom: 12px;
}
.reset-modal-text {
    font-size: 15px;
    color: var(--text-secondary, #666);
    margin-bottom: 8px;
}
.reset-modal-list {
    text-align: left;
    max-width: 260px;
    margin: 0 auto 16px;
    padding-left: 20px;
    font-size: 14px;
    color: var(--text-secondary, #666);
    line-height: 1.8;
}
.reset-modal-list li::marker {
    color: #FF4343;
}
.reset-modal-warning {
    font-size: 13px;
    font-weight: 700;
    color: #FF4343;
    margin-bottom: 24px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.reset-modal-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
}
.reset-modal-actions .btn {
    min-width: 130px;
}
.btn-danger {
    background: #FF4343 !important;
    color: #fff !important;
    border: none;
}
.btn-danger:hover {
    background: #e03030 !important;
}
.btn-danger:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}
@media (max-width: 768px) {
    .admin-stats { grid-template-columns: repeat(2, 1fr); }
    .admin-table { font-size: 12px; }
    .admin-table th, .admin-table td { padding: 8px 10px; }
}