:root {
    /* ========================================
       SEMANTIC COLOR SYSTEM - LIGHT MODE
    ======================================== */

    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --bg-elevated: #ffffff;
    --bg-overlay: rgba(0, 0, 0, 0.5);

    /* Text Colors */
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --text-inverse: #ffffff;
    --text-link: #2563eb;
    --text-link-hover: #1e40af;

    /* Border Colors */
    --border-primary: #e5e7eb;
    --border-secondary: #d1d5db;
    --border-subtle: rgba(0, 0, 0, 0.05);
    --border-focus: #c2eaff;

    /* Interactive Colors */
    --interactive-primary: #111827;
    --interactive-primary-hover: #2A2A2A;
    --interactive-secondary: #c2eaff;
    --interactive-secondary-hover: #a8dcff;
    --interactive-muted: transparent;
    --interactive-muted-hover: rgba(0, 0, 0, 0.04);

    /* Status Colors */
    --status-success: #10b981;
    --status-success-bg: #d1fae5;
    --status-success-text: #065f46;
    --status-error: #ef4444;
    --status-error-bg: #fee2e2;
    --status-error-text: #991b1b;
    --status-warning: #f59e0b;
    --status-warning-bg: #fef3c7;
    --status-warning-text: #92400e;
    --status-info: #2563eb;

    /* Shadow Colors */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 8px 24px rgba(0, 0, 0, 0.15);
    --shadow-accent: 0 4px 12px rgba(194, 234, 255, 0.4);

    /* Gradient Colors */
    --gradient-hero: linear-gradient(180deg, #ADD8E6 0%, #E6F3FF 50%, #FFFFFF 100%);
    --gradient-accent: linear-gradient(135deg, #c2eaff 0%, #a8dcff 100%);
    --gradient-progress: linear-gradient(90deg, #2563eb 0%, #10b981 100%);

    /* Navbar Specific */
    --navbar-bg: rgba(255, 255, 255, 0.8);
    --navbar-text: #111827;
    --navbar-border: rgba(0, 0, 0, 0.05);
    --navbar-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);

    /* Mobile Menu */
    --mobile-menu-bg: #ffffff;
    --mobile-nav-bg: #f3f4f6;
    --mobile-nav-hover: #e5e7eb;

    /* Special Use */
    --accent-sky: #87cefa;
    --accent-green: #ebf1c7;
    --rank-gold: #fbbf24;
    --rank-silver: #9ca3af;
    --rank-bronze: #d97706;

    /* Legacy Color Variables */
    --success-color: #10b981;
    --danger-color: #ef4444;
    --primary-color: #2563eb;

    /* Table Colors */
    --table-bg: #ffffff;
    --table-header-bg: #84ccf3;
    --table-row-hover: #e9ecef;
    --table-border: #dddddd;

    /* Input/Form */
    --input-bg: #ffffff;
    --input-border: #e5e7eb;
    --input-focus-ring: rgba(37, 99, 235, 0.1);

    /* Hover/Focus States */
    --hover-overlay: rgba(0, 0, 0, 0.04);
    --focus-ring: #c2eaff;

    /* Font Smoothing */
    --font-smoothing: antialiased;
}

/* ========================================
   DARK MODE OVERRIDES
======================================== */
[data-theme="dark"] {
    /* Background Colors */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-elevated: #1e293b;
    --bg-overlay: rgba(0, 0, 0, 0.75);

    /* Text Colors */
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    --text-inverse: #0f172a;
    --text-link: #60a5fa;
    --text-link-hover: #93c5fd;

    /* Border Colors */
    --border-primary: #334155;
    --border-secondary: #475569;
    --border-subtle: rgba(255, 255, 255, 0.05);
    --border-focus: #3b82f6;

    /* Interactive Colors */
    --interactive-primary: #3b82f6;
    --interactive-primary-hover: #60a5fa;
    --interactive-secondary: #1e40af;
    --interactive-secondary-hover: #1e3a8a;
    --interactive-muted: transparent;
    --interactive-muted-hover: rgba(255, 255, 255, 0.05);

    /* Status Colors */
    --status-success: #10b981;
    --status-success-bg: rgba(16, 185, 129, 0.15);
    --status-success-text: #34d399;
    --status-error: #ef4444;
    --status-error-bg: rgba(239, 68, 68, 0.15);
    --status-error-text: #f87171;
    --status-warning: #f59e0b;
    --status-warning-bg: rgba(245, 158, 11, 0.15);
    --status-warning-text: #fbbf24;
    --status-info: #3b82f6;

    /* Shadow Colors - Darker and more subtle */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 8px 24px rgba(0, 0, 0, 0.6);
    --shadow-accent: 0 4px 12px rgba(59, 130, 246, 0.3);

    /* Gradient Colors - Dark mode versions */
    --gradient-hero: linear-gradient(180deg, #1e3a5f 0%, #1e293b 50%, #0f172a 100%);
    --gradient-accent: linear-gradient(135deg, #1e40af 0%, #1e3a8a 100%);
    --gradient-progress: linear-gradient(90deg, #3b82f6 0%, #10b981 100%);

    /* Navbar Specific */
    --navbar-bg: rgba(15, 23, 42, 0.9);
    --navbar-text: #f1f5f9;
    --navbar-border: rgba(255, 255, 255, 0.05);
    --navbar-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);

    /* Mobile Menu */
    --mobile-menu-bg: #1e293b;
    --mobile-nav-bg: #334155;
    --mobile-nav-hover: #475569;

    /* Special Use */
    --accent-sky: #0ea5e9;
    --accent-green: #4ade80;
    --rank-gold: #fbbf24;
    --rank-silver: #cbd5e1;
    --rank-bronze: #fb923c;

    /* Table Colors */
    --table-bg: #1e293b;
    --table-header-bg: #1e40af;
    --table-row-hover: #334155;
    --table-border: #334155;

    /* Input/Form */
    --input-bg: #334155;
    --input-border: #475569;
    --input-focus-ring: rgba(59, 130, 246, 0.2);

    /* Hover/Focus States */
    --hover-overlay: rgba(255, 255, 255, 0.05);
    --focus-ring: #3b82f6;

    /* Font Smoothing - Better for dark backgrounds */
    --font-smoothing: auto;

    color-scheme: dark;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
    -webkit-font-smoothing: var(--font-smoothing);
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.navbar {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    color: var(--navbar-text);
    padding: 0;
    box-shadow: var(--navbar-shadow);
    border-bottom: 1px solid var(--navbar-border);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: all 0.3s ease;
}

.navbar-container {
    max-width: 1360px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 48px;
    height: 64px;
}

.navbar .container {
    max-width: 1360px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 48px;
    height: 64px;
}

.navbar-left {
    display: flex;
    align-items: center;
    gap: 32px;
}

.navbar-logo {
    height: 32px;
    width: auto;
    transition: filter 0.3s ease;
}

/* Dark theme navbar */
[data-theme="dark"] .navbar {
    background: #1e293b;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid #334155;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

/* Dark theme navbar logo */
[data-theme="dark"] .navbar-logo {
    filter: brightness(1) invert(1);
}

/* Change logo to footer logo on non-home pages in dark theme */
body.not-home-page[data-theme="dark"] .navbar-logo {
    content: url("/static/images/footer-logo.7266e6ac7c23.svg");
    filter: brightness(1) invert(1);
}

/* Dark theme burger menu - white for better visibility */
[data-theme="dark"] .hamburger-menu span {
    background: #f1f5f9;
}

[data-theme="dark"] .hamburger-menu:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* Dark theme navbar links - white on hover */
[data-theme="dark"] .navbar-nav a {
    color: #94a3b8;
}

[data-theme="dark"] .navbar-nav a:hover {
    color: #ffffff;
}

/* Dark theme login button - white background with black text */
[data-theme="dark"] .btn-nav-primary {
    background: #ffffff !important;
    color: #111827 !important;
}

[data-theme="dark"] .btn-nav-primary:hover {
    background: #f1f5f9 !important;
    color: #111827 !important;
}

[data-theme="dark"] .mobile-theme-toggle {
    background: rgba(51, 65, 85, 0.3);
    border-top: 1px solid #475569;
}

[data-theme="dark"] .mobile-theme-label {
    color: #e2e8f0;
}

[data-theme="dark"] .mobile-menu {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
}

[data-theme="dark"] .mobile-menu-header {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    border-bottom: 1px solid #334155;
}

[data-theme="dark"] .mobile-menu-header h3 {
    color: #f1f5f9;
}

[data-theme="dark"] .mobile-menu-close {
    color: #94a3b8;
}

[data-theme="dark"] .mobile-menu-close:hover {
    color: #f1f5f9;
    background: rgba(148, 163, 184, 0.1);
}

[data-theme="dark"] .mobile-nav-link {
    color: #e2e8f0;
}

[data-theme="dark"] .mobile-nav-link:hover {
    background: rgba(148, 163, 184, 0.1);
}

[data-theme="dark"] .mobile-menu-divider {
    border-top: 1px solid #334155;
}

[data-theme="dark"] .mobile-btn-register {
    color: #f1f5f9 !important;
    border: 1px solid #475569;
    background: rgba(51, 65, 85, 0.3);
}

[data-theme="dark"] .mobile-btn-register:hover {
    background: rgba(71, 85, 105, 0.5);
    border-color: #60a5fa;
}

[data-theme="dark"] .mobile-btn-login {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.3);
}

[data-theme="dark"] .mobile-btn-login:hover {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
}

.navbar-brand {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.2s;
    display: flex;
    align-items: center;
}

.navbar-brand:hover {
    opacity: 0.8;
}

.navbar-link {
    font-size: 0.9375rem;
    font-weight: 400;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.navbar-link:hover {
    color: var(--text-primary);
}

.navbar-nav {
    display: flex;
    list-style: none;
    gap: 24px;
    align-items: center;
    margin: 0;
    padding: 0;
}

.navbar-nav a {
    font-size: 0.9375rem;
    font-weight: var(--font-weight-normal);
    color: var(--text-soft);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.navbar-nav a:hover {
    color: var(--text-dark);
}

.btn-nav-primary {
    background: var(--interactive-primary);
    color: var(--text-inverse) !important;
    padding: 10px 20px;
    border-radius: 100px;
    font-weight: 500 !important;
    transition: all 0.2s ease;
}

.btn-nav-primary:hover {
    background: var(--interactive-primary-hover) !important;
    transform: translateY(-1px);
}

.btn-nav {
    background: transparent;
    color: var(--text-primary) !important;
    padding: 10px 20px;
    border: 1px solid var(--border-primary);
    border-radius: 6px;
    font-weight: 500 !important;
    transition: all 0.2s;
}

.btn-nav:hover {
    background: var(--hover-overlay) !important;
}

.auth-search-link {
    display: flex;
    align-items: center;
    gap: 6px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.auth-search-link:hover {
    color: var(--text-primary);
}

/* ========================================
   THEME TOGGLE BUTTON
======================================== */
.theme-toggle-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    padding: 0;
    border: none;
    background: var(--hover-overlay);
    border-radius: 8px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.theme-toggle-btn:hover {
    background: var(--interactive-muted-hover);
    color: var(--text-primary);
    transform: scale(1.05);
}

.theme-toggle-btn:active {
    transform: scale(0.95);
}

.theme-toggle-btn svg {
    width: 20px;
    height: 20px;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.theme-toggle-btn:hover svg {
    transform: rotate(20deg);
}

/* Theme toggle animations */
@keyframes rotate-in {
    from {
        transform: rotate(-180deg);
        opacity: 0;
    }
    to {
        transform: rotate(0deg);
        opacity: 1;
    }
}

.theme-toggle-btn .sun-icon,
.theme-toggle-btn .moon-icon {
    animation: rotate-in 0.3s ease-out;
}

.btn {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    border-radius: 1.275rem;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
}

.btn-primary:hover {
    background-color: var(--secondary-color);
}

.btn-secondary {
    background-color: #c2eaff;
    color: #fff;
}

.btn-secondary:hover {
    background-color: #c2eaff;
}

.btn-success {
    background-color: var(--success-color);
    color: #fff;
}

.btn-danger {
    background-color: var(--danger-color);
    color: #fff;
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: #000000;
}

.hero {
    background: var(--gradient-hero);
    color: #fff;
    padding: 4rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
}

.search-box {
    max-width: 600px;
    margin: 2rem auto;
}

.search-box input {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
}

.card {
    background-color: var(--bg-elevated);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.card-text {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    font-size: 1rem;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.alert {
    padding: 1rem;
    border-radius: 0.375rem;
    margin-bottom: 1rem;
}

.alert-success {
    background-color: var(--status-success-bg);
    color: var(--status-success-text);
    border: 1px solid var(--status-success);
}

.alert-error {
    background-color: var(--status-error-bg);
    color: var(--status-error-text);
    border: 1px solid var(--status-error);
}

.alert-warning {
    background-color: var(--status-warning-bg);
    color: var(--status-warning-text);
    border: 1px solid var(--status-warning);
}

.progress-bar {
    width: 100%;
    height: 1.5rem;
    background-color: var(--border-color);
    border-radius: 0.75rem;
    overflow: hidden;
    margin: 1rem 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--success-color) 100%);
    transition: width 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 600;
}

.question-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: 0rem 0;
}

.question-btn {
    width: 50px;
    height: 50px;
    border: 2px solid var(--border-color);
    border-radius: 0.375rem;
    background-color: var(--bg-elevated);
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s;
}

.question-btn:hover {
    border-color: var(--primary-color);
}

.question-btn.active {
    background-color: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
}

.question-btn.correct {
    background-color: var(--success-color);
    color: #fff;
    border-color: var(--success-color);
}

.question-btn.wrong {
    background-color: var(--danger-color);
    color: #fff;
    border-color: var(--danger-color);
}

.answer-option {
    display: block;
    padding: 1rem;
    margin-bottom: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s;
}

.answer-option:hover {
    border-color: var(--primary-color);
    background-color: #eff6ff;
}

.answer-option input[type="radio"] {
    margin-right: 0.75rem;
}

.timer {
    position: fixed;
    top: 80px;
    right: 20px;
    background-color: var(--dark-bg);
    color: #fff;
    padding: 1rem 1.5rem;
    border-radius: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
}

.leaderboard-table th,
.leaderboard-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.leaderboard-table th {
    background-color: var(--dark-bg);
    color: #fff;
    font-weight: 600;
}

.leaderboard-table tr:hover {
    background-color: var(--light-bg);
}

.rank-gold {
    color: var(--rank-gold);
    font-weight: 700;
}

.rank-silver {
    color: var(--rank-silver);
    font-weight: 700;
}

.rank-bronze {
    color: var(--rank-bronze);
    font-weight: 700;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: var(--bg-elevated);
    padding: 2rem;
    border-radius: 0.5rem;
    max-width: 900px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 600;
}

.close {
    font-size: 2rem;
    cursor: pointer;
    border: none;
    background: none;
}

/* .subscription-locked {
    opacity: 0.5;
    /* pointer-events: none; 
} */

.locked-badge {
    display: inline-block;
    background-color: var(--danger-color);
    color: #fff;
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.875rem;
    font-weight: 600;
    margin-left: 0.5rem;
}

.payment-icon {
    transition: opacity 0.3s ease;
    opacity: 0.9;
}

.payment-icon:hover {
    opacity: 1;
}

/* ========================================
   COURSE & TEST PAGES
======================================== */
.question-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.question-btn {
    min-width: 48px;
    height: 48px;
    border: 2px solid var(--border-color);
    background: var(--bg-elevated);
    border-radius: 0.375rem;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s;
}

.question-btn:hover {
    border-color: var(--primary-color);
}

.question-btn.active {
    background: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
}

.question-btn.answered {
    background: var(--success-color);
    color: #fff;
    border-color: var(--success-color);
}

.question-btn.incorrect {
    background: var(--danger-color);
    color: #fff;
    border-color: var(--danger-color);
}

.answer-option {
    display: block;
    padding: 1rem;
    margin-bottom: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s;
}

.answer-option:hover {
    border-color: var(--primary-color);
    background-color: #f0f7ff;
}

.answer-option input[type="radio"] {
    margin-right: 0.75rem;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.modal-content {
    background-color: var(--bg-elevated);
    margin: 5% auto;
    padding: 2rem;
    border-radius: 0.5rem;
    max-width: 800px;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 600;
}

.close {
    font-size: 2rem;
    font-weight: 300;
    color: var(--text-secondary);
    cursor: pointer;
    border: none;
    background: none;
    padding: 0;
    line-height: 1;
}

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

.alert {
    padding: 1rem 1.5rem;
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
    border-left: 4px solid;
}

.alert-warning {
    background-color: var(--status-warning-bg);
    color: var(--status-warning-text);
    border: 1px solid var(--status-warning);
}

.alert-error {
    background-color: var(--status-error-bg);
    color: var(--status-error-text);
    border: 1px solid var(--status-error);
}

.alert-success {
    background-color: var(--status-success-bg);
    color: var(--status-success-text);
    border: 1px solid var(--status-success);
}

.alert a {
    color: inherit;
    text-decoration: underline;
    font-weight: 600;
}

/* ========================================
   HAMBURGER MENU & MOBILE NAVIGATION
======================================== */
/* Hamburger Menu Button */
.hamburger-menu {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    transition: background 0.2s;
    margin-left: auto;
}

.hamburger-menu:hover {
    background: var(--hover-overlay);
}

.hamburger-menu span {
    display: block;
    width: 24px;
    height: 2px;
    background: #111827;
    margin: 3px 0;
    transition: all 0.3s;
    border-radius: 2px;
}

.hamburger-menu.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.hamburger-menu.active span:nth-child(2) {
    opacity: 0;
}

.hamburger-menu.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Mobile Menu Overlay */
.mobile-menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 998;
    opacity: 0;
    transition: opacity 0.3s;
}

.mobile-menu-overlay.active {
    display: block;
    opacity: 1;
}

/* Mobile Slide-out Menu */
.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    right: -100%;
    width: 320px;
    max-width: 85vw;
    height: 100vh;
    background: var(--mobile-menu-bg);
    box-shadow: -4px 0 12px rgba(0, 0, 0, 0.1);
    z-index: 999;
    overflow-y: auto;
    transition: right 0.3s ease;
    padding: 20px;
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding: 16px;
    border-bottom: 1px solid var(--border-primary);
}

.mobile-menu-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.mobile-menu-close {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    cursor: pointer;
    border-radius: 6px;
    transition: background 0.2s;
    font-size: 24px;
    color: var(--text-secondary);
}

.mobile-menu-close:hover {
    background: var(--hover-overlay);
}

.mobile-menu-content {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.mobile-nav-links {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.mobile-nav-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--mobile-nav-bg);
    border: 1px solid var(--border-primary);
    border-radius: 8px;
    color: var(--text-primary) !important;
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
    transition: all 0.2s;
}

.mobile-nav-link:hover {
    background: var(--mobile-nav-hover);
    border-color: #d1d5db;
}

.mobile-nav-link svg {
    flex-shrink: 0;
    color: var(--text-secondary);
}

.mobile-nav-link.logout-link {
    background: #fee2e2;
    border-color: #fecaca;
    color: #991b1b !important;
}

.mobile-nav-link.logout-link:hover {
    background: #fecaca;
    border-color: #fca5a5;
}

.mobile-nav-link.logout-link svg {
    color: #ef4444;
}

.mobile-menu-divider {
    border: none;
    border-top: 1px solid var(--border-primary);
    margin: 8px 0;
}

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

.mobile-btn-register,
.mobile-btn-login {
    display: block;
    text-align: center;
    padding: 12px 20px;
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.9375rem;
    text-decoration: none;
    transition: all 0.2s;
}

.mobile-btn-register {
    background: transparent;
    color: var(--text-primary) !important;
    border: 1px solid var(--border-primary);
}

.mobile-btn-register:hover {
    background: #f3f4f6;
    border-color: #d1d5db;
}

.mobile-btn-login {
    background: #111827;
    color: #fff !important;
    border: none;
}

.mobile-btn-login:hover {
    background: #2A2A2A;
    transform: translateY(-1px);
}

/* Mobile Theme Toggle */
.mobile-theme-toggle {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 16px;
    margin-top: 12px;
    border-top: 1px solid var(--border-primary);
    border-radius: 8px;
    background: var(--hover-overlay);
}

.mobile-theme-btn {
    flex-shrink: 0;
}

.mobile-theme-label {
    flex: 1;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
}

/* ========================================
   RESPONSIVE DESIGN - TABLET
======================================== */
@media (max-width: 1024px) {
    .container {
        padding: 0 24px;
    }

    .navbar-nav {
        gap: 1.5rem;
    }

    .hero {
        padding: 3rem 0;
    }

    .hero h1 {
        font-size: 2.25rem;
    }

    .hero p {
        font-size: 1.125rem;
    }

    .grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 1.25rem;
    }

    .card {
        padding: 1.25rem;
    }

    .card-title {
        font-size: 1.375rem;
    }
}

/* ========================================
   RESPONSIVE DESIGN - MOBILE
======================================== */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    .navbar {
        padding: 0;
    }

    .navbar-container {
        padding: 0 16px;
    }

    /* Show hamburger menu and hide desktop nav on mobile */
    .hamburger-menu {
        display: flex;
    }

    .navbar-left .navbar-link,
    .navbar-nav {
        display: none !important;
    }

    .mobile-menu {
        display: block;
    }

    .navbar-brand {
        font-size: 1.25rem;
    }

    .hero {
        padding: 2.5rem 0;
    }

    .hero h1 {
        font-size: 1.875rem;
        line-height: 1.2;
    }

    .hero p {
        font-size: 1rem;
        margin-bottom: 1.5rem;
    }

    .search-box {
        max-width: 100%;
        margin: 1.5rem auto;
    }

    .search-box input {
        padding: 0.875rem;
        font-size: 0.9375rem;
    }

    .grid {
        grid-template-columns: 1fr;
        gap: 1rem;
        margin: 1.5rem 0;
    }

    .card {
        padding: 1rem;
        margin-bottom: 1rem;
    }

    .card-title {
        font-size: 1.25rem;
    }

    .card-text {
        font-size: 0.9375rem;
    }

    .btn {
        padding: 0.625rem 1.25rem;
        font-size: 0.9375rem;
        width: 100%;
        text-align: center;
    }

    .form-control {
        padding: 0.625rem;
        font-size: 0.9375rem;
    }

    .timer {
        position: static;
        margin: 1rem auto;
        text-align: center;
    }

    /* Tables responsive */
    table {
        display: block;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    /* Course & Test Pages */
    .question-nav {
        gap: 0.375rem;
        margin-bottom: 1.5rem;
    }

    .question-btn {
        min-width: 40px;
        height: 40px;
        font-size: 0.875rem;
    }

    .answer-option {
        padding: 0.75rem;
        font-size: 0.9375rem;
    }

    .modal-content {
        margin: 10% 5%;
        padding: 1.5rem;
        max-width: 95%;
    }

    .modal-title {
        font-size: 1.25rem;
    }

    .alert {
        padding: 0.875rem 1.25rem;
        font-size: 0.9375rem;
    }

    /* Flexbox buttons */
    [style*="display: flex"][style*="gap"] {
        flex-wrap: wrap;
    }

    /* Exam detail page */
    [style*="grid-template-columns"] {
        grid-template-columns: 1fr !important;
    }
}

/* ========================================
   RESPONSIVE DESIGN - SMALL MOBILE
======================================== */
@media (max-width: 480px) {
    .container {
        padding: 0 12px;
    }

    .navbar-container {
        padding: 0 12px;
    }

    .navbar-brand {
        font-size: 1.125rem;
    }

    .mobile-menu {
        width: 100%;
        max-width: 100%;
    }

    .mobile-menu-header h3 {
        font-size: 1rem;
    }

    .hero h1 {
        font-size: 1.5rem;
    }

    .hero p {
        font-size: 0.9375rem;
    }

    .card {
        padding: 0.875rem;
    }

    .card-title {
        font-size: 1.125rem;
    }

    .card-text {
        font-size: 0.875rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }

    /* Course & Test Pages */
    .question-nav {
        gap: 0.25rem;
    }

    .question-btn {
        min-width: 36px;
        height: 36px;
        font-size: 0.8125rem;
    }

    .answer-option {
        padding: 0.625rem;
        font-size: 0.875rem;
        margin-bottom: 0.5rem;
    }

    .answer-option input[type="radio"] {
        margin-right: 0.5rem;
    }

    .modal-content {
        margin: 15% 3%;
        padding: 1rem;
        max-width: 94%;
        max-height: 70vh;
    }

    .modal-header {
        margin-bottom: 1rem;
        padding-bottom: 0.75rem;
    }

    .modal-title {
        font-size: 1.125rem;
    }

    .close {
        font-size: 1.5rem;
    }

    .alert {
        padding: 0.75rem 1rem;
        font-size: 0.875rem;
    }

    /* Headers in main content */
    h1 {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 1.25rem;
    }

    h3 {
        font-size: 1.125rem;
    }
}

/* ========================================
   UTILITY CLASSES FOR RESPONSIVE
======================================== */
.hide-mobile {
    display: block;
}

.show-mobile {
    display: none;
}

/* ========================================
   UTILITY CLASSES FOR LAYOUT
======================================== */
.mt-3 {
    margin-top: 3rem;
}

.mt-2 {
    margin-top: 2rem;
}

.mt-1 {
    margin-top: 1rem;
}

.max-w-500 {
    max-width: 500px;
}

.max-w-600 {
    max-width: 600px;
}

.mx-auto {
    margin-left: auto;
    margin-right: auto;
}

.user-card-highlight {
    background-color: #eff6ff !important;
    border-color: var(--primary-color) !important;
}

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

.answer-form {
    margin-top: 1.5rem;
}

.form-actions {
    margin-top: 1.5rem;
    display: flex;
    gap: 1rem;
    justify-content: space-between;
}

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

.profile-details {
    margin: 1.5rem 0;
}

.legal-footer {
    color: var(--text-secondary);
    margin-top: 2rem;
}

@media (max-width: 768px) {
    .hide-mobile {
        display: none !important;
    }

    .show-mobile {
        display: block !important;
    }

    .test-header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }

    .form-actions {
        flex-direction: column;
    }

    .form-actions-right {
        flex-direction: column;
    }
}

/* Ensure images are responsive */
img {
    max-width: 100%;
    height: auto;
}

/* Prevent horizontal overflow */
body {
    overflow-x: hidden;
}

/* Touch-friendly minimum sizes */
@media (max-width: 768px) {

    button,
    a.btn,
    input[type="submit"],
    input[type="button"] {
        min-height: 44px;
        min-width: 44px;
    }

    input[type="text"],
    input[type="email"],
    input[type="password"],
    input[type="number"],
    textarea,
    select {
        min-height: 44px;
    }

    /* Center aligned content on mobile */
    [style*="max-width: 600px"] {
        max-width: 100% !important;
    }

    /* Ensure proper spacing on mobile */
    [style*="margin-top: 3rem"] {
        margin-top: 1.5rem !important;
    }

    [style*="margin: 2rem"] {
        margin: 1rem !important;
    }

    /* Button groups responsive */
    [style*="display: flex; gap"] button,
    [style*="display: flex; gap"] .btn {
        flex: 1;
        min-width: auto;
    }
}

/* Ensure proper text wrapping */
.card-title,
.card-text,
h1,
h2,
h3,
h4,
h5,
h6,
p {
    word-wrap: break-word;
    overflow-wrap: break-word;
}

/* ========================================
   LEADERBOARD & TABLES
======================================== */
.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 2rem;
    background: var(--bg-elevated);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    border-radius: 0.5rem;
    overflow: hidden;
}

.leaderboard-table thead {
    background-color: var(--dark-bg);
    color: #fff;
}

.leaderboard-table th,
.leaderboard-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.leaderboard-table th {
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
}

.leaderboard-table tbody tr:hover {
    background-color: var(--light-bg);
}

.leaderboard-table tbody tr:last-child td {
    border-bottom: none;
}

.rank-gold {
    color: var(--rank-bronze);
    font-weight: 700;
    font-size: 1.125rem;
}

.rank-silver {
    color: var(--text-secondary);
    font-weight: 700;
    font-size: 1.125rem;
}

.rank-bronze {
    color: var(--rank-bronze);
    font-weight: 700;
    font-size: 1.125rem;
}

@media (max-width: 768px) {
    .leaderboard-table {
        font-size: 0.875rem;
    }

    .leaderboard-table th,
    .leaderboard-table td {
        padding: 0.75rem 0.5rem;
    }

    .leaderboard-table th {
        font-size: 0.8125rem;
    }

    .rank-gold,
    .rank-silver,
    .rank-bronze {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .leaderboard-table {
        font-size: 0.8125rem;
    }

    .leaderboard-table th,
    .leaderboard-table td {
        padding: 0.625rem 0.375rem;
    }

    .leaderboard-table th:nth-child(2),
    .leaderboard-table td:nth-child(2) {
        max-width: 150px;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }
}

/* Основні стилі для таблиці */
.sales-table {
    width: 100%;
    max-width: 600px;
    /* Обмеження ширини для кращого вигляду */
    border-collapse: collapse;
    /* Об'єднання меж клітинок */
    font-family: Arial, Helvetica, sans-serif;
    margin: 20px auto;
    /* Центрування таблиці на сторінці */
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    /* Легка тінь */
}

/* Стилі для заголовка таблиці (caption) */
.sales-table caption {
    font-size: 1.2em;
    font-weight: bold;
    margin-bottom: 10px;
    padding: 5px;
    color: #333;
}

/* Стилі для клітинок заголовка та даних */
.sales-table th,
.sales-table td {
    border: 1px solid #dddddd;
    padding: 12px;
    /* Відступи всередині клітинок */
    text-align: center;
    /* Центрування тексту */
}

/* Стиль для шапки таблиці */
.sales-table thead th {
    background-color: #84ccf3;
    /* Синій фон заголовка */
    color: white;
    /* Білий текст заголовка */
}

/* Стиль для першого стовпця (назви категорій) */
.sales-table tbody th {
    text-align: left;
    background-color: #f8f9fa;
}

/* Ефект при наведенні на рядок */
.sales-table tbody tr:hover {
    background-color: #e9ecef;
}


/* Клас для картинок у тестах/запитаннях */
.test-image {
    max-width: 100%;
    /* Картинка не буде ширшою за батьківський блок */
    height: auto;
    display: block;
    margin: 20px auto;
    /* Центрування по горизонталі + відступи зверху/знизу */
    border: 1px solid #e2e8f0;
    /* Легка сіра рамка */
    border-radius: 8px;
    /* Закруглені кути */
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    /* Легка тінь для об'єму */

    /* Обмеження розміру, щоб графік не був гігантським на моніторах */
    max-height: 400px;
    object-fit: contain;
    /* Показує всю картинку, не обрізаючи її */
    background-color: var(--bg-elevated);
    /* Білий фон, якщо картинка прозора */
}

/* Ефект при наведенні (опціонально) */
.test-image:hover {
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.1);
    border-color: #cbd5e1;
    transition: all 0.3s ease;
}