/* CSS Design System for Data Science Level 2 Practice Portal */

:root {
    /* Dark Theme Variables (Default) */
    --bg-primary: #0a0e17;
    --bg-secondary: #0f1524;
    --bg-tertiary: #161f38;
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    
    --accent-blue: #3b82f6;
    --accent-blue-hover: #2563eb;
    --accent-blue-glow: rgba(59, 130, 246, 0.25);
    
    --accent-purple: #8b5cf6;
    --accent-purple-hover: #7c3aed;
    --accent-purple-glow: rgba(139, 92, 246, 0.25);
    
    --accent-cyan: #06b6d4;
    --accent-cyan-hover: #0891b2;
    --accent-cyan-glow: rgba(6, 182, 212, 0.25);
    
    --accent-green: #10b981;
    --accent-green-hover: #059669;
    --accent-green-glow: rgba(16, 185, 129, 0.25);
    
    --accent-red: #ef4444;
    --accent-red-hover: #dc2626;
    --accent-red-glow: rgba(239, 68, 68, 0.25);
    
    --card-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
    --sidebar-shadow: 4px 0 24px rgba(0, 0, 0, 0.3);
    
    --terminal-bg: #05070c;
    --code-bg: #0c101b;
}

/* Light Theme Variables */
.light-theme {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --border-color: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 0, 0, 0.15);
    
    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    
    --accent-blue: #2563eb;
    --accent-blue-hover: #1d4ed8;
    --accent-blue-glow: rgba(37, 99, 235, 0.15);
    
    --accent-purple: #7c3aed;
    --accent-purple-hover: #6d28d9;
    --accent-purple-glow: rgba(124, 58, 237, 0.15);
    
    --accent-cyan: #0891b2;
    --accent-cyan-hover: #0e7490;
    --accent-cyan-glow: rgba(8, 145, 178, 0.15);
    
    --accent-green: #059669;
    --accent-green-hover: #047857;
    --accent-green-glow: rgba(5, 150, 105, 0.15);
    
    --accent-red: #dc2626;
    --accent-red-hover: #b91c1c;
    --accent-red-glow: rgba(220, 38, 38, 0.15);
    
    --card-shadow: 0 10px 30px -15px rgba(0, 0, 0, 0.1);
    --sidebar-shadow: 4px 0 24px rgba(0, 0, 0, 0.05);
    
    --terminal-bg: #0f172a;
    --code-bg: #f8fafc;
}

/* General Resets */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
    transition: background-color 0.3s ease, border-color 0.3s ease, color 0.15s ease;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
}

img,
svg,
canvas,
video {
    max-width: 100%;
}

h1, h2, h3, h4 {
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    color: var(--text-primary);
}

p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Layout Container */
.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Sidebar Navigation */
.sidebar {
    width: 260px;
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    box-shadow: var(--sidebar-shadow);
    z-index: 10;
    flex-shrink: 0;
}

.sidebar-header {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    flex-direction: column;
}

.logo-samsung {
    font-family: 'Outfit', sans-serif;
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: 2px;
    color: var(--accent-blue);
    text-shadow: 0 0 10px var(--accent-blue-glow);
}

.logo-dx {
    font-family: 'Outfit', sans-serif;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted);
    letter-spacing: 1px;
}

.user-profile {
    display: flex;
    align-items: center;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    gap: 12px;
}

.avatar {
    width: 42px;
    height: 42px;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.user-info {
    display: flex;
    flex-direction: column;
    min-width: 0;
    flex: 1;
}

.username {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.badge {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.profile-auth-btn {
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 6px 8px;
    font-size: 0.72rem;
    font-weight: 700;
    cursor: pointer;
    flex-shrink: 0;
}

.profile-auth-btn:hover {
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

.nav-menu {
    flex-grow: 1;
    padding: 24px 16px;
}

.nav-menu ul {
    list-style: none;
}

.nav-item {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 8px;
    cursor: pointer;
    gap: 12px;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
}

.nav-item i {
    font-size: 1.1rem;
    width: 20px;
    text-align: center;
}

.nav-item:hover {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

.nav-item.active {
    background: linear-gradient(90deg, var(--accent-blue-glow), transparent);
    border-left: 3px solid var(--accent-blue);
    color: var(--text-primary);
    font-weight: 600;
}

.sidebar-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.theme-toggle {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

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

.env-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.status-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: #e2e8f0;
}

.status-indicator.ready {
    background-color: var(--accent-green);
    box-shadow: 0 0 8px var(--accent-green);
}

.status-indicator.loading {
    background-color: #fbbf24;
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0% { opacity: 0.4; }
    50% { opacity: 1; }
    100% { opacity: 0.4; }
}

/* Main Content Wrapper */
.main-content {
    flex-grow: 1;
    min-width: 0;
    overflow-y: auto;
    position: relative;
    display: flex;
    flex-direction: column;
}

.mobile-header,
.sidebar-overlay {
    display: none;
}

/* Page transitions */
.content-screen {
    display: none;
    flex-grow: 1;
    flex-direction: column;
    padding: 30px;
    min-width: 0;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.content-screen.active {
    display: flex;
    opacity: 1;
    transform: translateY(0);
}

body.auth-locked .sidebar,
body.auth-locked .main-content {
    filter: blur(2px);
    pointer-events: none;
    user-select: none;
}

body.auth-locked .modal-close-btn {
    display: none;
}

/* Headers */
.content-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
}

.content-header h1 {
    font-size: 1.8rem;
    margin-bottom: 6px;
    letter-spacing: -0.5px;
}

.subtitle {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.date-badge {
    background-color: var(--bg-secondary);
    padding: 6px 12px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    font-size: 0.8rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

/* Stats Cards Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
    gap: 20px;
    margin-bottom: 24px;
}

.stat-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 20px;
    box-shadow: var(--card-shadow);
}

.stat-icon {
    width: 50px;
    height: 50px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
}

.stats-blue {
    background-color: var(--accent-blue-glow);
    color: var(--accent-blue);
}

.stats-purple {
    background-color: var(--accent-purple-glow);
    color: var(--accent-purple);
}

.stats-green {
    background-color: var(--accent-green-glow);
    color: var(--accent-green);
}

.stat-details h3 {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
    margin-bottom: 4px;
}

.stat-value {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-primary);
    font-family: 'Outfit', sans-serif;
}

.stat-value .unit {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 400;
}

.stat-meta {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 4px;
}

/* General Layout Grids */
.dashboard-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
    align-items: start;
    min-width: 0;
}

@media (max-width: 1024px) {
    .dashboard-layout {
        grid-template-columns: 1fr;
    }
}

.dashboard-panel {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--card-shadow);
    margin-bottom: 24px;
    min-width: 0;
}

.dashboard-panel h2 {
    font-size: 1.15rem;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 12px;
}

.icon-accent {
    color: var(--accent-blue);
}

/* Guideline Cards */
.guidelines-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.guideline-card {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 18px;
    position: relative;
    overflow: hidden;
}

.badge-tag {
    position: absolute;
    top: 18px;
    right: 18px;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}

.tag-blue {
    background-color: var(--accent-blue-glow);
    color: var(--accent-blue);
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.tag-purple {
    background-color: var(--accent-purple-glow);
    color: var(--accent-purple);
    border: 1px solid rgba(139, 92, 246, 0.3);
}

.tag-cyan {
    background-color: var(--accent-cyan-glow);
    color: var(--accent-cyan);
    border: 1px solid rgba(6, 182, 212, 0.3);
}

.tag-green {
    background-color: var(--accent-green-glow);
    color: var(--accent-green);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.guideline-card h3 {
    font-size: 1rem;
    margin-bottom: 8px;
    padding-right: 80px;
}

.guideline-card p {
    font-size: 0.85rem;
    margin-bottom: 14px;
}

.guideline-card ul {
    list-style: none;
}

.guideline-card li {
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 6px;
    color: var(--text-secondary);
}

.text-blue { color: var(--accent-blue); }
.text-purple { color: var(--accent-purple); }

/* Quick Buttons */
.quick-start-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.quick-btn {
    width: 100%;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-hover);
    border-radius: 10px;
    padding: 16px;
    display: flex;
    align-items: center;
    text-align: left;
    cursor: pointer;
    gap: 16px;
    color: var(--text-primary);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.02);
}

.quick-btn:hover {
    border-color: var(--text-muted);
    transform: translateX(4px);
}

.quick-btn.btn-blue,
.quick-btn.btn-purple,
.quick-btn.btn-cyan {
    color: var(--text-primary);
}

.quick-btn.btn-blue {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.18), var(--bg-tertiary));
}

.quick-btn.btn-purple {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.18), var(--bg-tertiary));
}

.quick-btn.btn-cyan {
    background: linear-gradient(135deg, rgba(6, 182, 212, 0.18), var(--bg-tertiary));
}

.quick-btn-icon {
    width: 42px;
    height: 42px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.15rem;
    flex-shrink: 0;
    border: 1px solid rgba(255, 255, 255, 0.16);
    box-shadow: 0 8px 18px rgba(0, 0, 0, 0.18);
}

.btn-blue .quick-btn-icon { background-color: var(--accent-blue); color: white; }
.btn-purple .quick-btn-icon { background-color: var(--accent-purple); color: white; }
.btn-cyan .quick-btn-icon { background-color: var(--accent-cyan); color: white; }

.quick-btn-text {
    flex-grow: 1;
    min-width: 0;
}

.quick-btn-text h4 {
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.quick-btn-text p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.45;
}

.quick-btn .arrow {
    font-size: 0.9rem;
    color: var(--text-primary);
    opacity: 0.85;
    flex-shrink: 0;
}

.tip-card {
    background: linear-gradient(135deg, var(--bg-tertiary), rgba(59, 130, 246, 0.05));
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 16px;
    margin-top: 20px;
}

.tip-header {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #fbbf24;
    font-weight: 600;
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.tip-card p {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Actions and Buttons */
.action-btn {
    padding: 10px 16px;
    border-radius: 8px;
    border: none;
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-blue {
    background-color: var(--accent-blue);
    color: white;
}
.btn-blue:hover { background-color: var(--accent-blue-hover); }

.btn-purple {
    background-color: var(--accent-purple);
    color: white;
}
.btn-purple:hover { background-color: var(--accent-purple-hover); }

.btn-cyan {
    background-color: var(--accent-cyan);
    color: white;
}
.btn-cyan:hover { background-color: var(--accent-cyan-hover); }

.btn-red {
    background-color: var(--accent-red);
    color: white;
}
.btn-red:hover { background-color: var(--accent-red-hover); }

.btn-secondary {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}
.btn-secondary:hover { background-color: var(--border-color); }

/* Landing Views / Mode Selection */
.screen-view {
    display: none;
    flex-grow: 1;
    flex-direction: column;
}

.screen-view.active {
    display: flex;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to { opacity: 1; transform: translateY(0); }
}

.mode-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
}

.mode-card {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
}

.mode-card:hover {
    border-color: var(--accent-blue);
    box-shadow: 0 4px 20px var(--accent-blue-glow);
}

.mode-icon {
    font-size: 2.2rem;
    color: var(--accent-blue);
}

.mode-card h3 {
    font-size: 1.1rem;
}

.mode-card p {
    font-size: 0.85rem;
}

.exam-set-status {
    display: flex;
    flex-direction: column;
    gap: 7px;
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: rgba(59, 130, 246, 0.06);
    color: var(--text-secondary);
    font-size: 0.78rem;
    line-height: 1.45;
}

.exam-set-status span {
    display: flex;
    align-items: center;
    gap: 8px;
}

.exam-set-status i {
    color: var(--accent-blue);
    width: 14px;
    text-align: center;
}

.category-buttons {
    display: flex;
    flex-direction: column;
    gap: 8px;
    width: 100%;
}

.cat-select-btn {
    width: 100%;
    text-align: left;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.cat-select-btn:hover {
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

/* History lists */
.history-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.empty-history {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 20px;
    color: var(--text-muted);
    gap: 10px;
}

.empty-history i {
    font-size: 1.8rem;
}

.empty-history p {
    font-size: 0.8rem;
    text-align: center;
}

.history-item {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 12px 16px;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.history-item.reviewable {
    cursor: pointer;
}

.history-item.reviewable:hover,
.history-item.reviewable:focus {
    border-color: var(--accent-blue);
    background-color: var(--accent-blue-glow);
    outline: none;
}

.history-item.not-reviewable {
    opacity: 0.72;
}

.history-item-info h4 {
    font-size: 0.85rem;
}

.history-item-info span {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.history-item-score {
    font-size: 1.05rem;
    font-weight: 700;
}

.score-pass { color: var(--accent-green); }
.score-fail { color: var(--accent-red); }

/* Written Quiz Interface */
.quiz-container {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--card-shadow);
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 16px;
    margin-bottom: 20px;
}

.quiz-progress-section {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-grow: 1;
    max-width: 70%;
}

.quiz-q-num {
    font-weight: 700;
    font-size: 1.05rem;
    min-width: 80px;
}

.progress-bar-bg {
    flex-grow: 1;
    height: 8px;
    background-color: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background-color: var(--accent-blue);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.progress-bar-fill.animated-stripes {
    background-image: linear-gradient(45deg, rgba(255, 255, 255, 0.15) 25%, transparent 25%, transparent 50%, rgba(255, 255, 255, 0.15) 50%, rgba(255, 255, 255, 0.15) 75%, transparent 75%, transparent);
    background-size: 1rem 1rem;
    animation: progress-stripes 1s linear infinite;
}

@keyframes progress-stripes {
    from { background-position: 1rem 0; }
    to { background-position: 0 0; }
}

.quiz-timer {
    display: flex;
    align-items: center;
    gap: 8px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 20px;
    font-weight: 700;
    font-family: 'Fira Code', monospace;
    font-size: 0.95rem;
}

.quiz-set-label {
    background-color: var(--accent-blue-glow);
    border: 1px solid rgba(59, 130, 246, 0.35);
    border-radius: 20px;
    color: var(--text-primary);
    padding: 6px 12px;
    font-size: 0.82rem;
    font-weight: 700;
}

.quiz-body-layout {
    display: grid;
    grid-template-columns: 1fr 260px;
    gap: 24px;
}

@media (max-width: 800px) {
    .quiz-body-layout {
        grid-template-columns: 1fr;
    }
}

.quiz-main-area {
    display: flex;
    flex-direction: column;
}

.question-box {
    margin-bottom: 24px;
}

.question-category {
    font-size: 0.75rem;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 4px 8px;
    border-radius: 4px;
    font-weight: 600;
    color: var(--accent-blue);
}

.question-text {
    font-size: 1.05rem;
    font-weight: 500;
    margin-top: 12px;
    line-height: 1.6;
}

.question-code {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 6px;
    margin-top: 16px;
    font-family: 'Fira Code', monospace;
    font-size: 0.85rem;
    overflow-x: auto;
    color: var(--text-secondary);
}

.options-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 24px;
}

.option-item {
    display: flex;
    align-items: center;
    border: 1px solid var(--border-color);
    padding: 14px 18px;
    border-radius: 8px;
    cursor: pointer;
    gap: 14px;
}

.option-item:hover {
    border-color: var(--border-hover);
    background-color: var(--bg-tertiary);
}

.option-item.selected {
    border-color: var(--accent-blue);
    background-color: var(--accent-blue-glow);
}

.option-radio {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    flex-shrink: 0;
}

.option-item.selected .option-radio {
    border-color: var(--accent-blue);
    background-color: var(--accent-blue);
    color: white;
}

.option-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.option-item.selected .option-label {
    color: var(--text-primary);
    font-weight: 500;
}

.quiz-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}

.nav-control-btn {
    padding: 10px 20px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    border: 1px solid var(--border-color);
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

.nav-control-btn:hover {
    background-color: var(--border-color);
}

.nav-control-btn.btn-blue {
    background-color: var(--accent-blue);
    color: white;
    border: none;
}
.nav-control-btn.btn-blue:hover { background-color: var(--accent-blue-hover); }

.nav-control-btn.btn-red {
    background-color: var(--accent-red);
    color: white;
    border: none;
}
.nav-control-btn.btn-red:hover { background-color: var(--accent-red-hover); }

/* Quiz Map Area */
.quiz-map-area {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 18px;
}

.quiz-map-area h3 {
    font-size: 0.95rem;
    margin-bottom: 14px;
}

.question-grid-map {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
    margin-bottom: 16px;
}

.map-btn {
    aspect-ratio: 1;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
}

.map-btn:hover {
    border-color: var(--text-muted);
}

.map-btn.answered {
    background-color: rgba(59, 130, 246, 0.15);
    border-color: rgba(59, 130, 246, 0.4);
    color: var(--accent-blue);
}

.map-btn.current {
    background-color: var(--accent-blue);
    border-color: var(--accent-blue);
    color: white;
    box-shadow: 0 0 10px var(--accent-blue-glow);
}

.quiz-map-legend {
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-size: 0.75rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    padding-top: 12px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
}

.legend-item .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--border-color);
    border: 1px solid var(--text-muted);
}

.legend-item .dot.answered {
    background-color: var(--accent-blue-glow);
    border-color: var(--accent-blue);
}

.legend-item .dot.active {
    background-color: var(--accent-blue);
    border-color: var(--accent-blue);
}

/* Results view */
.result-container {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.result-summary-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
    text-align: center;
    box-shadow: var(--card-shadow);
}

.result-badge {
    display: inline-block;
    padding: 6px 16px;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.95rem;
    background-color: var(--accent-green-glow);
    color: var(--accent-green);
    border: 1px solid rgba(16, 185, 129, 0.4);
    margin-bottom: 16px;
}

.result-badge.fail {
    background-color: var(--accent-red-glow);
    color: var(--accent-red);
    border: 1px solid rgba(239, 68, 68, 0.4);
}

.result-score-text {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 8px;
}

.result-summary-card p {
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.category-breakdown {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--card-shadow);
}

.category-stat-row {
    margin-bottom: 16px;
}

.category-stat-row:last-child {
    margin-bottom: 0;
}

.cat-stat-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 6px;
    font-size: 0.85rem;
}

.cat-stat-label {
    font-weight: 600;
}

.cat-stat-pct {
    color: var(--text-muted);
}

.explanations-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.explanation-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    box-shadow: var(--card-shadow);
}

.explanation-card.correct { border-left: 4px solid var(--accent-green); }
.explanation-card.incorrect { border-left: 4px solid var(--accent-red); }

.explanation-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 12px;
    margin-bottom: 12px;
}

.explanation-title {
    font-size: 0.95rem;
    font-weight: 700;
}

.explanation-tag {
    font-size: 0.75rem;
    padding: 4px 8px;
    border-radius: 4px;
    font-weight: 600;
}

.correct .explanation-tag { background-color: var(--accent-green-glow); color: var(--accent-green); }
.incorrect .explanation-tag { background-color: var(--accent-red-glow); color: var(--accent-red); }

.explanation-body {
    font-size: 0.9rem;
    line-height: 1.6;
}

.explanation-choices-review {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin: 16px 0;
}

.choice-review-item {
    padding: 10px;
    border-radius: 6px;
    font-size: 0.85rem;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

.choice-review-item.user-select {
    border-color: var(--accent-red);
    background-color: var(--accent-red-glow);
}

.choice-review-item.correct-choice {
    border-color: var(--accent-green);
    background-color: var(--accent-green-glow);
}

.explanation-text-box {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 14px;
    border-radius: 6px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.explanation-text-box strong {
    color: var(--text-primary);
}

/* Practical Lab List */
.labs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(320px, 100%), 1fr));
    gap: 20px;
    margin-top: 20px;
}

.lab-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--card-shadow);
    gap: 12px;
}

.lab-card:hover {
    border-color: var(--accent-purple);
    transform: translateY(-2px);
}

.lab-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.lab-meta-row {
    display: flex;
    gap: 8px;
}

.lab-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
}

.lab-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: auto;
}

.lab-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--border-color);
    padding-top: 14px;
    margin-top: 10px;
}

.lab-status-tag {
    font-size: 0.75rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 4px;
}

.lab-status-tag.solved { color: var(--accent-green); }
.lab-status-tag.unsolved { color: var(--text-muted); }

/* Practical Blank Quiz */
.practical-mode-tabs.is-hidden {
    display: none;
}

.blank-practice-shell {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.blank-practice-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 18px;
}

.blank-practice-header h2 {
    font-size: 1.18rem;
    margin-bottom: 6px;
}

.blank-practice-stats {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 8px;
    flex: 0 0 auto;
}

.blank-practice-stats span {
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 6px 10px;
    font-size: 0.8rem;
    font-weight: 700;
}

.blank-practice-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.blank-practice-controls > div,
.blank-practice-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: var(--card-shadow);
}

.blank-practice-controls > div {
    padding: 16px;
}

.blank-practice-controls h3 {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.blank-filter-row,
.blank-practice-actions,
.blank-card-actions,
.blank-hint-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.blank-filter-btn {
    min-height: 38px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 8px 12px;
    font-size: 0.82rem;
    font-weight: 700;
    cursor: pointer;
}

.blank-filter-btn:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
}

.blank-filter-btn.active {
    border-color: var(--accent-purple);
    background-color: var(--accent-purple-glow);
    color: var(--text-primary);
}

#blank-wrong-only-btn.active {
    border-color: var(--accent-red);
    color: var(--accent-red);
}

.blank-practice-card {
    padding: 22px;
    display: flex;
    flex-direction: column;
    gap: 14px;
    min-width: 0;
}

.blank-empty-state {
    min-height: 260px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    text-align: center;
    color: var(--text-secondary);
}

.blank-empty-state i {
    color: var(--accent-purple);
    font-size: 1.8rem;
}

.blank-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 10px;
}

.blank-progress {
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 5px 10px;
    font-size: 0.78rem;
    font-weight: 800;
    white-space: nowrap;
}

.blank-practice-card h3 {
    font-size: 1.16rem;
}

.blank-prompt {
    color: var(--text-secondary);
    line-height: 1.55;
}

.blank-code-block {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: #e2e8f0;
    font-family: 'Fira Code', monospace;
    font-size: 0.82rem;
    line-height: 2.1;
    overflow-x: auto;
    padding: 16px;
    white-space: pre;
}

.blank-code-block code {
    font-family: inherit;
}

.blank-answer-input {
    min-width: 130px;
    max-width: 230px;
    border: 1px solid var(--accent-blue);
    border-radius: 6px;
    background-color: rgba(59, 130, 246, 0.12);
    color: var(--text-primary);
    font-family: 'Fira Code', monospace;
    font-size: 0.82rem;
    outline: none;
    padding: 6px 8px;
}

.blank-answer-input:focus {
    box-shadow: 0 0 0 2px var(--accent-blue-glow);
}

.blank-answer-input::placeholder {
    color: var(--text-muted);
}

.blank-answer-input:disabled {
    opacity: 0.85;
    cursor: default;
}

body.light-theme .blank-code-block {
    background-color: #f8fafc !important;
    color: #0f172a !important;
    border-color: rgba(15, 23, 42, 0.16) !important;
}

body.light-theme .blank-answer-input {
    background-color: #eff6ff !important;
    color: #0f172a !important;
    border-color: #2563eb !important;
}

body.light-theme .blank-answer-input::placeholder {
    color: #64748b !important;
}

.blank-hint-list span {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 7px 9px;
    font-size: 0.8rem;
}

.blank-hint-list strong {
    color: var(--text-primary);
}

.blank-result-panel {
    border-radius: 10px;
    border: 1px solid var(--border-color);
    padding: 14px;
}

.blank-result-panel.correct {
    border-color: rgba(16, 185, 129, 0.45);
    background-color: rgba(16, 185, 129, 0.08);
}

.blank-result-panel.wrong {
    border-color: rgba(239, 68, 68, 0.45);
    background-color: rgba(239, 68, 68, 0.08);
}

.blank-result-panel h4 {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
}

.blank-result-panel ul {
    list-style: none;
    display: grid;
    gap: 6px;
    margin-bottom: 12px;
}

.blank-result-panel li {
    font-family: 'Fira Code', monospace;
    font-size: 0.8rem;
}

.blank-result-panel li.correct {
    color: var(--accent-green);
}

.blank-result-panel li.wrong {
    color: var(--accent-red);
}

.blank-result-explanation {
    color: var(--text-secondary);
    line-height: 1.55;
}

.blank-result-explanation strong {
    color: var(--text-primary);
}

.blank-result-explanation span {
    display: inline-flex;
    margin-top: 8px;
    border-radius: 20px;
    background-color: var(--bg-tertiary);
    padding: 5px 9px;
    font-size: 0.78rem;
    font-weight: 800;
    color: var(--accent-cyan);
}

/* Function Cheatsheet */
.function-cheatsheet-toolbar {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 18px;
}

.function-search {
    flex: 1 1 360px;
    margin-bottom: 0;
}

.function-filter-block {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 18px;
}

.function-filter-block > div {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    box-shadow: var(--card-shadow);
}

.function-filter-block h3 {
    font-size: 0.9rem;
    margin-bottom: 10px;
    color: var(--text-secondary);
}

.function-filter-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.function-filter-btn {
    min-height: 38px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 8px 12px;
    font-size: 0.82rem;
    font-weight: 700;
    cursor: pointer;
}

.function-filter-btn:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
}

.function-filter-btn.active {
    border-color: var(--accent-purple);
    background-color: var(--accent-purple-glow);
    color: var(--text-primary);
}

.function-result-summary {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-bottom: 14px;
    color: var(--text-muted);
    font-size: 0.82rem;
}

.function-result-summary span {
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background-color: var(--bg-secondary);
    padding: 6px 10px;
}

.function-cheatsheet-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(360px, 100%), 1fr));
    gap: 18px;
}

.function-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--card-shadow);
    display: flex;
    flex-direction: column;
    gap: 14px;
    min-width: 0;
}

.function-card:hover {
    border-color: var(--accent-purple);
}

.function-card-header {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    align-items: flex-start;
}

.function-library-badge,
.function-category-badge {
    display: inline-flex;
    align-items: center;
    min-height: 26px;
    border-radius: 999px;
    padding: 4px 9px;
    font-size: 0.72rem;
    font-weight: 800;
}

.function-library-badge {
    background-color: var(--accent-blue-glow);
    color: var(--accent-blue);
}

.function-category-badge {
    background-color: var(--accent-cyan-glow);
    color: var(--accent-cyan);
}

.function-copy-btn {
    min-height: 34px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 7px 10px;
    font-size: 0.78rem;
    font-weight: 800;
    cursor: pointer;
    flex: 0 0 auto;
}

.function-copy-btn:hover {
    color: var(--text-primary);
    border-color: var(--accent-blue);
}

.function-card h3 {
    font-family: 'Fira Code', monospace;
    font-size: 1.12rem;
    color: var(--text-primary);
}

.function-meta-list {
    display: grid;
    gap: 7px 12px;
}

.function-meta-list dt {
    color: var(--text-muted);
    font-size: 0.76rem;
    font-weight: 800;
}

.function-meta-list dd {
    color: var(--text-secondary);
    font-size: 0.84rem;
    line-height: 1.55;
    margin-bottom: 4px;
}

.function-meta-list code {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 2px 5px;
    color: var(--accent-cyan);
}

.function-code-block {
    margin-top: auto;
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 14px;
    overflow-x: auto;
    color: #e2e8f0;
    font-family: 'Fira Code', monospace;
    font-size: 0.78rem;
    line-height: 1.55;
}

.function-empty-state {
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    min-height: 260px;
    border: 1px dashed var(--border-hover);
    border-radius: 12px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    text-align: center;
    padding: 28px;
}

.function-empty-state i {
    color: var(--accent-purple);
    font-size: 1.6rem;
}

/* Practical IDE Layout */
.workspace-layout {
    display: grid;
    grid-template-columns: 380px 1fr;
    height: calc(100vh - 140px);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
}

@media (max-width: 900px) {
    .workspace-layout {
        grid-template-columns: 1fr;
        height: auto;
    }
}

.workspace-pane {
    background-color: var(--bg-secondary);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.pane-instructions {
    border-right: 1px solid var(--border-color);
}

.pane-header {
    background-color: var(--bg-tertiary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
}

.tab-item {
    padding: 12px 20px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    border-bottom: 2px solid transparent;
}

.tab-item:hover {
    color: var(--text-primary);
}

.tab-item.active {
    color: var(--accent-purple);
    border-bottom-color: var(--accent-purple);
    background-color: var(--bg-secondary);
}

.pane-body {
    flex-grow: 1;
    overflow-y: auto;
    padding: 20px;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

#lab-workspace-title {
    font-size: 1.15rem;
    margin-bottom: 4px;
}

.lab-difficulty {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.instructions-rich-text {
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

.instructions-rich-text h3 {
    font-size: 0.95rem;
    margin-top: 18px;
    margin-bottom: 8px;
    color: var(--text-primary);
    border-left: 3px solid var(--accent-purple);
    padding-left: 8px;
}

.instructions-rich-text ol, .instructions-rich-text ul {
    margin-left: 20px;
    margin-top: 8px;
}

.instructions-rich-text li {
    margin-bottom: 6px;
}

.instructions-rich-text code {
    background-color: var(--code-bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Fira Code', monospace;
    font-size: 0.75rem;
    color: var(--accent-purple);
}

.data-dict-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.8rem;
    margin-top: 10px;
}

.data-dict-table th, .data-dict-table td {
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    text-align: left;
}

.data-dict-table th {
    background-color: var(--bg-tertiary);
    font-weight: 600;
}

.pane-footer-buttons {
    padding: 12px 20px;
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-tertiary);
}

/* IDE coding panes */
.pane-coding {
    display: flex;
    flex-direction: column;
}

.editor-window {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    min-height: 250px;
    border-bottom: 1px solid var(--border-color);
}

.editor-header {
    background-color: var(--bg-tertiary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 16px;
}

.editor-title-file {
    font-size: 0.8rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
}

.text-yellow { color: #f59e0b; }

.editor-actions {
    display: flex;
    gap: 8px;
}

.editor-btn {
    border: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    padding: 6px 12px;
    border-radius: 4px;
    font-size: 0.75rem;
    cursor: pointer;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 4px;
}

.editor-btn:hover {
    background-color: var(--border-color);
}

.editor-btn.btn-blue {
    background-color: var(--accent-blue);
    color: white;
    border: none;
}
.editor-btn.btn-blue:hover { background-color: var(--accent-blue-hover); }

.editor-btn.btn-red {
    background-color: var(--accent-red);
    color: white;
    border: none;
}
.editor-btn.btn-red:hover { background-color: var(--accent-red-hover); }

.editor-editor-area {
    flex-grow: 1;
    position: relative;
    display: flex;
    background-color: var(--code-bg);
}

.line-numbers {
    width: 40px;
    padding: 16px 0;
    border-right: 1px solid var(--border-color);
    background-color: rgba(0, 0, 0, 0.15);
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: 'Fira Code', monospace;
    font-size: 0.8rem;
    color: var(--text-muted);
    user-select: none;
    line-height: 1.5;
}

.code-textarea {
    flex-grow: 1;
    border: none;
    background: transparent;
    color: #e2e8f0;
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 0.85rem;
    padding: 16px;
    resize: none;
    outline: none;
    line-height: 1.5;
    white-space: pre;
    overflow: auto;
}

/* Console window styles */
.console-window {
    height: 180px;
    background-color: var(--terminal-bg);
    display: flex;
    flex-direction: column;
}

.console-header {
    background-color: rgba(0,0,0,0.2);
    border-bottom: 1px solid var(--border-color);
    padding: 8px 16px;
    font-size: 0.75rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-secondary);
}

.console-clear-btn {
    border: none;
    background: transparent;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 0.75rem;
}

.console-clear-btn:hover {
    color: var(--text-primary);
}

.console-terminal {
    flex-grow: 1;
    overflow-y: auto;
    padding: 12px 16px;
    font-family: 'Fira Code', monospace;
    font-size: 0.8rem;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.console-line {
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-all;
    color: #cbd5e1;
}

.console-line.system-line { color: var(--text-muted); }
.console-line.error-line { color: var(--accent-red); }
.console-line.success-line { color: var(--accent-green); }
.console-line.output-line { color: #facc15; }

/* Cheat Sheet Layout */
.cheat-tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 24px;
    gap: 8px;
}

.cheat-tab-btn,
.flash-tab-btn,
.practical-tab-btn {
    background: transparent;
    border: none;
    padding: 10px 16px;
    min-height: 40px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    border-bottom: 2px solid transparent;
}

.cheat-tab-btn:hover,
.flash-tab-btn:hover,
.practical-tab-btn:hover {
    color: var(--text-primary);
}

.cheat-tab-btn.active,
.flash-tab-btn.active,
.practical-tab-btn.active {
    color: var(--accent-blue);
    border-bottom-color: var(--accent-blue);
}

.cheat-tab-content {
    display: none;
}

.cheat-tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

.search-container {
    position: relative;
    margin-bottom: 24px;
}

.search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1rem;
}

#cheat-search-input,
#theory-search-input,
#function-search-input {
    width: 100%;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 12px 16px 12px 44px;
    color: var(--text-primary);
    font-size: 0.9rem;
    outline: none;
}

#cheat-search-input:focus,
#theory-search-input:focus,
#function-search-input:focus {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 2px var(--accent-blue-glow);
}

.theory-toolbar {
    display: flex;
    align-items: stretch;
    gap: 12px;
    margin-bottom: 18px;
}

.theory-search {
    flex: 1;
    margin-bottom: 0;
}

.theory-source-link {
    flex-shrink: 0;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-width: 128px;
}

.theory-status {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    padding: 14px 16px;
    margin-bottom: 16px;
}

.theory-status.error {
    border-color: rgba(239, 68, 68, 0.35);
    color: var(--accent-red);
}

.theory-document {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 28px;
    box-shadow: var(--card-shadow);
    max-width: 1100px;
}

.theory-document h1,
.theory-document h2,
.theory-document h3 {
    scroll-margin-top: 24px;
}

.theory-document h1 {
    font-size: 1.65rem;
    margin-bottom: 18px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.theory-document h2 {
    font-size: 1.25rem;
    margin: 30px 0 12px;
    border-left: 4px solid var(--accent-blue);
    padding-left: 10px;
}

.theory-document h3 {
    font-size: 1.05rem;
    margin: 22px 0 10px;
    color: var(--accent-cyan);
}

.theory-document p,
.theory-document li {
    font-size: 0.94rem;
    line-height: 1.75;
    color: var(--text-secondary);
}

.theory-document p {
    margin: 10px 0;
}

.theory-document ul,
.theory-document ol {
    margin: 10px 0 14px 22px;
}

.theory-document li + li {
    margin-top: 5px;
}

.theory-document strong {
    color: var(--text-primary);
}

.theory-document code {
    font-family: 'Fira Code', monospace;
    font-size: 0.85em;
    color: #38bdf8;
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 2px 5px;
}

.theory-document pre {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 14px;
    overflow-x: auto;
    margin: 14px 0;
}

.theory-document pre code {
    background: transparent;
    border: 0;
    padding: 0;
}

.theory-document table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    overflow: hidden;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.theory-document th,
.theory-document td {
    border: 1px solid var(--border-color);
    padding: 10px 12px;
    text-align: left;
    color: var(--text-secondary);
    vertical-align: top;
    font-size: 0.9rem;
}

.theory-document th {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    font-weight: 700;
}

.theory-document blockquote {
    border-left: 4px solid var(--accent-purple);
    background-color: var(--bg-tertiary);
    border-radius: 0 8px 8px 0;
    margin: 14px 0;
    padding: 10px 14px;
}

.theory-document hr {
    border: 0;
    border-top: 1px solid var(--border-color);
    margin: 26px 0;
}

.theory-document .math-display {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 12px;
    margin: 14px 0;
    overflow-x: auto;
}

.theory-document mark {
    background-color: rgba(250, 204, 21, 0.24);
    color: var(--text-primary);
    border-radius: 3px;
    padding: 0 2px;
}

.formulas-container {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.formula-category-section h2 {
    font-size: 1.2rem;
    margin-bottom: 16px;
    border-left: 4px solid var(--accent-blue);
    padding-left: 10px;
}

.formula-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(360px, 100%), 1fr));
    gap: 20px;
}

.formula-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    box-shadow: var(--card-shadow);
}

.formula-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 10px;
}

.formula-card h3 {
    font-size: 1rem;
    font-weight: 700;
}

.formula-tag {
    font-size: 0.7rem;
    font-weight: 600;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--accent-blue);
}

.formula-desc {
    font-size: 0.85rem;
    margin-bottom: 14px;
}

.formula-math {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 14px;
    text-align: center;
    font-size: 1rem;
    font-family: 'Outfit', sans-serif;
    color: var(--text-primary);
    overflow-x: auto;
    margin-bottom: 14px;
}

.formula-code-sample {
    border-radius: 6px;
    overflow: hidden;
}

.code-title {
    display: block;
    background-color: rgba(0,0,0,0.15);
    padding: 6px 12px;
    font-size: 0.75rem;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
    border-bottom: none;
    font-weight: 500;
}

.formula-code-sample pre {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    padding: 12px;
    margin: 0;
    overflow-x: auto;
    max-width: 100%;
}

.formula-code-sample code {
    display: block;
    max-width: 100%;
    font-family: 'Fira Code', monospace;
    font-size: 0.75rem;
    color: #38bdf8;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    word-break: break-word;
}

/* Stat Calculators */
.calculator-layout {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 24px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--card-shadow);
}

@media (max-width: 800px) {
    .calculator-layout {
        grid-template-columns: 1fr;
    }
}

.calc-inputs h3, .calc-results h3 {
    font-size: 1.05rem;
    margin-bottom: 8px;
}

.desc-text {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.input-group-dual {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.group-side {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 8px;
}

.group-side h4 {
    font-size: 0.85rem;
    margin-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 6px;
}

.input-field {
    margin-bottom: 12px;
}

.input-field:last-child {
    margin-bottom: 0;
}

.input-field label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.input-field input, .input-field select {
    width: 100%;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 8px;
    color: var(--text-primary);
    font-size: 0.85rem;
    outline: none;
}

.input-field input:focus, .input-field select:focus {
    border-color: var(--accent-blue);
}

.margin-top-med { margin-top: 16px; }
.margin-top-large { margin-top: 24px; }

.calculator-results-box {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
}

.result-row {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.85rem;
}

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

.result-row.highlight-blue {
    color: var(--accent-blue);
    font-weight: 700;
}

.result-row.highlight-purple {
    color: var(--accent-purple);
    font-weight: 700;
}

.result-row.highlight-green {
    color: var(--accent-green);
    font-weight: 700;
}

.result-row .value {
    font-family: 'Fira Code', monospace;
    font-weight: 600;
}

.decision-card {
    background-color: rgba(16, 185, 129, 0.05);
    border: 1px solid rgba(16, 185, 129, 0.2);
    border-radius: 8px;
    padding: 16px;
    margin-top: 16px;
}

.decision-card.reject {
    background-color: rgba(239, 68, 68, 0.05);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.decision-title {
    font-size: 0.85rem;
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--text-primary);
}

.decision-text {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Confusion Matrix Interactive Grid */
.confusion-matrix-input-table {
    display: grid;
    grid-template-columns: 120px 1fr 1fr;
    gap: 10px;
    margin-bottom: 16px;
}

.cm-cell {
    display: flex;
    flex-direction: column;
    justify-content: center;
    border-radius: 6px;
    padding: 10px;
    border: 1px solid var(--border-color);
}

.cm-cell.header-cell {
    background-color: var(--bg-tertiary);
    font-size: 0.75rem;
    font-weight: 600;
    text-align: center;
    align-items: center;
}

.cm-cell.label-cell {
    background-color: var(--bg-tertiary);
    font-size: 0.75rem;
    font-weight: 600;
    align-items: flex-start;
}

.cm-cell.input-cell {
    background-color: var(--bg-secondary);
}

.cell-title {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 4px;
}

.cm-cell input {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
    font-family: 'Fira Code', monospace;
    font-size: 0.95rem;
    font-weight: 700;
    outline: none;
}

.cm-cell input:focus {
    border-bottom-color: var(--accent-blue);
}

.bg-tp { background-color: rgba(16, 185, 129, 0.05); border-color: rgba(16, 185, 129, 0.2); }
.bg-tn { background-color: rgba(16, 185, 129, 0.03); border-color: rgba(16, 185, 129, 0.1); }
.bg-fp { background-color: rgba(239, 68, 68, 0.05); border-color: rgba(239, 68, 68, 0.2); }
.bg-fn { background-color: rgba(239, 68, 68, 0.03); border-color: rgba(239, 68, 68, 0.1); }

.calc-tips {
    margin-top: 14px;
    font-size: 0.75rem;
    color: var(--text-muted);
    display: flex;
    flex-direction: column;
    gap: 6px;
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    z-index: 100;
    display: none;
    align-items: center;
    justify-content: center;
    overflow-y: auto;
    padding: 16px;
}

.modal-overlay.active {
    display: flex;
}

.modal-content {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 28px;
    max-width: 500px;
    width: 90%;
    max-height: calc(100vh - 32px);
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: modalSlide 0.3s ease;
}

@keyframes modalSlide {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

.modal-content h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.modal-content p {
    font-size: 0.85rem;
    margin-bottom: 20px;
}

.modal-btn-row {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
}

.auth-modal-content {
    max-width: 420px;
}

.auth-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    margin-bottom: 10px;
}

.auth-modal-header h3 {
    margin-bottom: 0;
}

.modal-close-btn {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    cursor: pointer;
}

.modal-close-btn:hover {
    color: var(--text-primary);
    border-color: var(--border-hover);
}

.auth-mode-toggle {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin: 18px 0;
}

.auth-mode-btn {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 9px 12px;
    font-weight: 700;
    cursor: pointer;
}

.auth-mode-btn.active {
    background-color: var(--accent-blue);
    border-color: var(--accent-blue);
    color: white;
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.auth-field {
    display: flex;
    flex-direction: column;
    gap: 7px;
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 700;
}

.auth-field input {
    width: 100%;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 11px 12px;
    outline: none;
}

.auth-field input:focus {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 2px var(--accent-blue-glow);
}

.auth-submit-btn {
    justify-content: center;
    margin-top: 4px;
}

.auth-submit-btn:disabled {
    cursor: wait;
    opacity: 0.72;
}

.auth-message {
    min-height: 18px;
    color: var(--accent-red);
    font-size: 0.78rem;
}

.auth-message.success {
    color: var(--accent-green);
}

.auth-note {
    margin-top: 14px;
    margin-bottom: 0 !important;
    color: var(--text-muted);
    font-size: 0.76rem;
}

.text-center { text-align: center; }

/* Loading Spinner */
.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--accent-purple);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Cursor pointers */
.cursor-pointer { cursor: pointer; }
.margin-top-large { margin-top: 24px; }
.margin-top-med { margin-top: 16px; }

/* -------------------------------------------------------------
   Flashcard Screen Specific Styles
   ------------------------------------------------------------- */
.flash-tab-content {
    display: none;
}
.flash-tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

.flashcard-control-panel {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 12px;
    margin-bottom: 24px;
    gap: 16px;
    flex-wrap: wrap;
}

.category-filters {
    display: flex;
    flex: 1 1 520px;
    flex-wrap: wrap;
    gap: 8px;
    min-width: 0;
}

.cat-filter-btn {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    line-height: 1.25;
    min-height: 34px;
    white-space: nowrap;
}

.cat-filter-btn:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
}

.cat-filter-btn.active {
    background-color: var(--accent-blue);
    border-color: var(--accent-blue);
    color: white;
}

.leitner-status-box {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    flex: 0 1 340px;
    min-width: 260px;
    font-size: 0.85rem;
}

.status-title {
    color: var(--text-muted);
    font-weight: 500;
}

.status-progress-text {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    margin-left: 6px;
}

/* Flashcard 3D Card Area */
.flashcard-arena {
    display: flex;
    justify-content: center;
    margin: 20px 0;
    perspective: 1000px;
}

.flashcard-container {
    width: 100%;
    max-width: 660px;
    height: 460px;
    cursor: pointer;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.flashcard-container.flipped .flashcard-inner {
    transform: rotateY(180deg);
}

.card-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 16px;
    padding: 30px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-width: 0;
    overflow: hidden;
}

.card-front {
    background-color: var(--bg-secondary);
    border-top: 5px solid var(--accent-blue);
}

.card-back {
    background-color: var(--bg-tertiary);
    border-top: 5px solid var(--accent-purple);
    transform: rotateY(180deg);
    align-items: flex-start;
    justify-content: flex-start;
    gap: 12px;
    overflow-y: auto;
    overscroll-behavior: contain;
}

.card-category {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    background-color: rgba(255, 255, 255, 0.05);
    padding: 4px 10px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    margin-bottom: 20px;
}

.card-front .card-category {
    color: var(--accent-blue);
}

.card-back .card-category {
    color: var(--accent-purple);
}

.card-main-question {
    font-size: 1.4rem;
    font-weight: 600;
    text-align: center;
    line-height: 1.5;
    color: var(--text-primary);
    padding: 0 10px;
}

.card-back h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.card-back-answer-box {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary);
    flex: 0 0 auto;
    width: 100%;
    min-height: auto;
    overflow-y: visible;
    padding-right: 4px;
}

.mnemonic-box {
    background: rgba(245, 158, 11, 0.05);
    border: 1px solid rgba(245, 158, 11, 0.2);
    border-radius: 8px;
    padding: 12px 16px;
    width: 100%;
    margin-top: 14px;
    flex-shrink: 0;
}

.mnemonic-badge {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.75rem;
    font-weight: 700;
    color: #f59e0b;
    margin-bottom: 6px;
}

.mnemonic-box p {
    font-size: 0.85rem;
    color: var(--text-primary);
    line-height: 1.4;
}

.card-flip-prompt {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 6px;
    margin-top: 20px;
    align-self: center;
}

/* Flashcard control buttons */
.flashcard-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-top: 20px;
    margin-bottom: 24px;
}

.leitner-action-btn {
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
}

.leitner-action-btn.btn-red {
    background-color: var(--accent-red-glow);
    color: var(--accent-red);
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.leitner-action-btn.btn-red:hover {
    background-color: var(--accent-red);
    color: white;
}

.leitner-action-btn.btn-green {
    background-color: var(--accent-green-glow);
    color: var(--accent-green);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.leitner-action-btn.btn-green:hover {
    background-color: var(--accent-green);
    color: white;
}

.flashcard-navigation {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    margin-top: 10px;
}

.card-index-indicator {
    font-family: 'Outfit', sans-serif;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
}

/* Mnemonic Layouts */
.mnemonic-intro-card {
    background: linear-gradient(135deg, var(--bg-secondary), rgba(59, 130, 246, 0.03));
    border: 1px solid var(--border-color);
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 24px;
}

.mnemonic-intro-card h3 {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.05rem;
    margin-bottom: 6px;
}

.mnemonic-intro-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.mnemonic-list-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 20px;
}

.mnemonic-note-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    box-shadow: var(--card-shadow);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.mnemonic-note-card:hover {
    border-color: rgba(245, 158, 11, 0.3);
}

.mnemonic-note-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

.mnemonic-note-header h4 {
    font-size: 0.95rem;
    font-weight: 700;
}

.mnemonic-note-body p {
    font-size: 0.85rem;
    margin-bottom: 12px;
}

.mnemonic-formula-display {
    background-color: var(--bg-tertiary);
    padding: 10px;
    border-radius: 6px;
    text-align: center;
    font-family: 'Outfit', sans-serif;
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 10px;
    border: 1px solid var(--border-color);
}

.mnemonic-tip-bubble {
    background-color: rgba(245, 158, 11, 0.05);
    border: 1px dashed rgba(245, 158, 11, 0.25);
    border-radius: 6px;
    padding: 10px 14px;
    font-size: 0.85rem;
    line-height: 1.5;
}

.mnemonic-acronym {
    font-size: 1.1rem;
    font-weight: 800;
    color: #f59e0b;
    letter-spacing: 2px;
}

/* Blank fill active recall box */
.blank-fill {
    display: inline-block;
    background-color: var(--accent-blue-glow);
    border-bottom: 2px solid var(--accent-blue);
    padding: 0 6px;
    border-radius: 3px;
    font-weight: 700;
    color: var(--accent-blue);
    cursor: pointer;
    transition: all 0.2s ease;
}

.blank-fill.hidden-blank {
    color: transparent !important;
    background-color: var(--bg-tertiary);
    border-bottom-color: var(--text-muted);
    user-select: none;
    min-width: 40px;
    text-shadow: none;
}

.blank-fill.hidden-blank:hover {
    background-color: var(--border-color);
}

/* -------------------------------------------------------------
   Responsive polish
   ------------------------------------------------------------- */
@media (max-width: 800px) {
    body {
        overflow: hidden;
    }

    .app-container {
        display: block;
    }

    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: min(82vw, 300px);
        transform: translateX(-105%);
        transition: transform 0.25s ease;
        z-index: 50;
    }

    .sidebar.active {
        transform: translateX(0);
    }

    .sidebar-overlay {
        display: none;
        position: fixed;
        inset: 0;
        background-color: rgba(2, 6, 23, 0.62);
        z-index: 40;
    }

    .sidebar-overlay.active {
        display: block;
    }

    .main-content {
        width: 100vw;
        height: 100vh;
    }

    .mobile-header {
        position: sticky;
        top: 0;
        z-index: 30;
        display: flex;
        align-items: center;
        justify-content: space-between;
        min-height: 56px;
        padding: 10px 16px;
        background-color: var(--bg-secondary);
        border-bottom: 1px solid var(--border-color);
    }

    .mobile-menu-trigger,
    .theme-toggle-mobile {
        width: 38px;
        height: 38px;
        border-radius: 8px;
        border: 1px solid var(--border-color);
        background-color: var(--bg-tertiary);
        color: var(--text-primary);
        display: inline-flex;
        align-items: center;
        justify-content: center;
        cursor: pointer;
    }

    .mobile-logo {
        min-width: 0;
        padding: 0 10px;
        color: var(--text-primary);
        font-family: 'Outfit', sans-serif;
        font-size: 0.98rem;
        font-weight: 700;
        text-align: center;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }

    .content-screen {
        padding: 18px 16px 26px;
    }

    .content-header {
        flex-direction: column;
        align-items: stretch;
    }

    .content-header h1 {
        font-size: 1.45rem;
    }

    .modal-overlay {
        align-items: flex-start;
        padding: 14px;
    }

    .modal-content {
        width: 100%;
        padding: 22px;
    }

    .auth-mode-toggle {
        margin: 14px 0;
    }

    .auth-note {
        line-height: 1.45;
    }

    .header-actions,
    .date-badge {
        align-self: flex-start;
    }

    .stat-card {
        padding: 16px;
        gap: 14px;
        align-items: flex-start;
    }

    .stat-icon {
        width: 42px;
        height: 42px;
        flex: 0 0 auto;
    }

    .dashboard-panel,
    .formula-card,
    .lab-card,
    .calculator-layout,
    .theory-document {
        padding: 18px;
        border-radius: 10px;
    }

    .cheat-tabs {
        flex-wrap: wrap;
        gap: 6px 10px;
        border-bottom: 0;
    }

    .cheat-tab-btn,
    .flash-tab-btn,
    .practical-tab-btn {
        flex: 1 1 calc(50% - 10px);
        min-width: 0;
        border: 1px solid var(--border-color);
        border-radius: 8px;
        background-color: var(--bg-secondary);
        padding: 9px 10px;
        line-height: 1.25;
        text-align: center;
    }

    .cheat-tab-btn.active,
    .flash-tab-btn.active,
    .practical-tab-btn.active {
        border-color: var(--accent-blue);
        background-color: var(--accent-blue-glow);
    }

    .theory-toolbar {
        flex-direction: column;
    }

    .theory-source-link {
        width: 100%;
    }

    .theory-document {
        max-width: 100%;
        overflow-x: auto;
    }

    .theory-document h1 {
        font-size: 1.32rem;
    }

    .theory-document h2 {
        font-size: 1.08rem;
    }

    .formula-math,
    .theory-document .math-display {
        text-align: left;
    }

    .formula-math mjx-container,
    .theory-document mjx-container {
        max-width: 100%;
        overflow-x: auto;
        overflow-y: hidden;
    }

    .quiz-header {
        align-items: stretch;
    }

    .quiz-progress-section {
        width: 100%;
        max-width: 100%;
    }

    .quiz-timer,
    .quiz-set-label {
        flex: 1 1 calc(50% - 6px);
        justify-content: center;
        min-height: 40px;
        text-align: center;
    }

    .cat-select-btn,
    .cat-filter-btn {
        min-height: 40px;
    }

    .input-group-dual {
        grid-template-columns: 1fr;
    }

    .result-row,
    .lab-card-footer,
    .function-cheatsheet-toolbar,
    .function-card-header,
    .mnemonic-note-header {
        flex-wrap: wrap;
        gap: 8px;
    }

    .function-cheatsheet-toolbar .action-btn {
        width: 100%;
        justify-content: center;
    }

    .function-filter-block {
        grid-template-columns: 1fr;
    }

    .function-filter-btn {
        flex: 1 1 calc(33.333% - 8px);
        min-height: 40px;
    }

    .blank-practice-header,
    .blank-card-header {
        flex-wrap: wrap;
    }

    .blank-practice-stats {
        justify-content: flex-start;
    }

    .blank-practice-controls {
        grid-template-columns: 1fr;
    }

    .blank-filter-btn {
        flex: 1 1 calc(33.333% - 8px);
        min-height: 40px;
    }

    .blank-practice-actions .action-btn,
    .blank-card-actions .action-btn {
        flex: 1 1 150px;
        justify-content: center;
        min-height: 40px;
    }

    .blank-practice-card {
        padding: 18px;
    }

    .blank-code-block {
        max-width: 100%;
    }

    .blank-answer-input {
        max-width: 100%;
    }

    .function-card {
        padding: 18px;
    }

    .function-copy-btn {
        min-height: 40px;
    }

    .function-code-block {
        max-width: 100%;
    }

    .lab-card-footer .action-btn {
        width: 100%;
    }

    .flashcard-control-panel {
        align-items: stretch;
    }

    .category-filters {
        flex-wrap: wrap;
    }

    .cat-filter-btn {
        flex: 1 1 calc(33.333% - 8px);
        padding: 9px 10px;
        white-space: normal;
    }

    .leitner-status-box {
        flex-wrap: wrap;
        min-width: 0;
        justify-content: flex-start;
        gap: 8px;
    }

    .leitner-status-box .progress-bar-bg {
        width: 100% !important;
        margin-left: 0 !important;
    }

    .flashcard-container {
        height: 500px;
    }

    .card-face {
        padding: 24px 22px;
    }

    .flashcard-actions,
    .flashcard-navigation {
        flex-wrap: wrap;
        gap: 10px;
    }

    .leitner-action-btn,
    .flashcard-navigation .nav-control-btn {
        flex: 1 1 140px;
        min-width: 0;
    }

    .card-index-indicator {
        order: -1;
        width: 100%;
        text-align: center;
    }

    .mnemonic-list-grid {
        grid-template-columns: 1fr;
    }

    .workspace-layout {
        max-width: 100%;
    }

    .pane-header {
        overflow-x: auto;
    }

    .editor-header {
        flex-wrap: wrap;
    }

    .editor-actions {
        width: 100%;
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
    }

    .editor-btn {
        flex: 1 1 120px;
    }
}

@media (max-width: 420px) {
    .content-screen {
        padding-left: 14px;
        padding-right: 14px;
    }

    .stat-card {
        flex-direction: column;
    }

    .formula-card-header {
        flex-direction: column;
    }

    .cheat-tab-btn,
    .flash-tab-btn,
    .practical-tab-btn {
        flex-basis: 100%;
    }

    .flashcard-container {
        height: 540px;
    }

    .cat-filter-btn {
        flex-basis: calc(50% - 8px);
    }

    .function-filter-btn {
        flex-basis: calc(50% - 8px);
    }

    .blank-filter-btn {
        flex-basis: calc(50% - 8px);
    }

    .blank-practice-actions .action-btn,
    .blank-card-actions .action-btn {
        flex-basis: 100%;
    }

    .quiz-timer,
    .quiz-set-label {
        flex-basis: 100%;
    }

    .quick-btn {
        align-items: flex-start;
        gap: 12px;
    }

    .quick-btn .arrow {
        margin-top: 8px;
    }

    .card-main-question {
        font-size: 1.2rem;
    }

    .card-back h3 {
        font-size: 1.1rem;
    }
}