/* ===================================================================
   ALGO SCHOOL - Modern CSS Design System
   A clean, professional, and accessible design
   =================================================================== */

/* ===== FONTS ===== */
@font-face {
    font-family: 'Cairo';
    src: url('fonts/Cairo-VariableFont_slnt,wght.ttf') format('truetype');
    font-weight: 400 700;
    font-style: normal;
    font-display: swap;
}

/* ===== CSS VARIABLES (Design Tokens) ===== */
:root {
    /* Primary Colors - Modern Blue Palette */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;

    /* Main colors */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #dbeafe;
    --secondary-color: #1e40af;

    /* Accent Colors */
    --accent-color: #f59e0b;
    --accent-hover: #d97706;
    --accent-light: #fef3c7;

    /* Success / Error / Warning */
    --success: #10b981;
    --success-light: #d1fae5;
    --error: #ef4444;
    --error-light: #fee2e2;
    --warning: #f59e0b;
    --warning-light: #fef3c7;

    /* Neutral Colors */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    /* Text Colors */
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-muted: #6b7280;
    --text-light: #9ca3af;

    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 200ms ease;
    --transition-slow: 300ms ease;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
}

/* ===== RESET & BASE ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: 'Cairo', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== TYPOGRAPHY ===== */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--text-primary);
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

h4 {
    font-size: 1.25rem;
}

h5 {
    font-size: 1.125rem;
}

h6 {
    font-size: 1rem;
}

p {
    color: var(--text-secondary);
    margin-bottom: var(--space-4);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-hover);
}

/* ===== LAYOUT ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-6);
}

/* ===== NAVIGATION ===== */
.main-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--gray-200);
    box-shadow: var(--shadow-sm);
    padding: var(--space-2) 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-6);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-logo:hover {
    color: var(--primary-hover);
}

.logo-img {
    height: 32px;
    width: auto;
}

.nav-links {
    list-style: none;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-1);
}

.nav-links li {
    margin: 0;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    text-decoration: none;
}

.nav-links a:hover {
    color: var(--primary-color);
    background-color: var(--primary-light);
}

.nav-links .fas {
    font-size: 0.85rem;
    margin-right: 3px;
}

.nav-toggle {
    display: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--text-primary);
    padding: var(--space-2);
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
}

.nav-toggle:hover {
    background-color: var(--gray-100);
}

/* ===== HERO SECTION ===== */
.hero {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--space-16) var(--space-6);
    min-height: 60vh;
    background: linear-gradient(135deg, var(--primary-50) 0%, var(--bg-secondary) 50%, var(--primary-100) 100%);
    overflow: hidden;
}

/* Floating decorative shapes */
.hero::before,
.hero::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.5;
    pointer-events: none;
    z-index: 0;
}

.hero::before {
    width: 400px;
    height: 400px;
    background: linear-gradient(135deg, var(--primary-300), var(--primary-400));
    top: -100px;
    left: -100px;
    animation: heroFloat 15s ease-in-out infinite;
}

.hero::after {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, var(--accent-color), var(--primary-500));
    bottom: -80px;
    right: -80px;
    animation: heroFloat 18s ease-in-out infinite reverse;
}

@keyframes heroFloat {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.05); }
    66% { transform: translate(-20px, 20px) scale(0.95); }
}

/* Subtle grid pattern */
.hero-pattern {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    z-index: 1;
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-6);
    max-width: 850px;
    position: relative;
    z-index: 10;
    animation: heroFadeIn 0.8s ease-out;
}

@keyframes heroFadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hero badge */
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary-600);
    margin-bottom: 0.5rem;
}

.hero-badge i {
    color: var(--primary-500);
}

.hero-content h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
    color: var(--primary-800);
    line-height: 1.15;
    margin-bottom: 0.75rem;
    letter-spacing: -0.02em;
}

.hero-content p {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    max-width: 650px;
    margin: 0 auto 1.5rem;
    line-height: 1.7;
}

/* Hero CTA buttons */
.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-top: 0.5rem;
}

.hero-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-lg);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
    font-family: inherit;
}

.hero-btn-primary {
    background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
    color: white;
    box-shadow: 0 8px 20px -6px rgba(37, 99, 235, 0.4);
}

.hero-btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 28px -6px rgba(37, 99, 235, 0.5);
    color: white;
}

.hero-btn-secondary {
    background: white;
    color: var(--primary-600);
    border: 2px solid var(--primary-200);
    box-shadow: var(--shadow-md);
}

.hero-btn-secondary:hover {
    background: var(--primary-50);
    border-color: var(--primary-300);
    transform: translateY(-3px);
    color: var(--primary-700);
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    white-space: nowrap;
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.btn:focus {
    outline: none;
    box-shadow: 0 0 0 3px var(--primary-200);
}

.btn:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: white;
}

/* Secondary Button */
.btn-secondary {
    background-color: var(--bg-primary);
    color: var(--primary-color);
    border-color: var(--primary-color);
}

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

/* Accent Button */
.btn-accent {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

.btn-accent:hover {
    background-color: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-2px);
}

/* Outline Button */
.btn-outline {
    background-color: transparent;
    color: var(--text-primary);
    border-color: var(--gray-300);
}

.btn-outline:hover {
    background-color: var(--gray-100);
    border-color: var(--gray-400);
}

/* Button Sizes */
.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: 0.875rem;
}

.btn-lg {
    padding: var(--space-4) var(--space-8);
    font-size: 1.125rem;
}

/* ===== FEATURED CONTENT ===== */
.featured-content {
    padding: var(--space-16) var(--space-6);
    text-align: center;
    background-color: var(--bg-primary);
}

.featured-content h2 {
    font-size: 2.25rem;
    margin-bottom: var(--space-12);
    color: var(--primary-800);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-8);
    max-width: 1200px;
    margin: 0 auto;
}

/* ===== FEATURE CARDS ===== */
.feature-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-primary);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    text-align: center;
    text-decoration: none;
    color: inherit;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-200);
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-card .fas,
.feature-card .fa-solid,
.feature-card i {
    font-size: 3rem;
    margin-bottom: var(--space-4);
    transition: transform var(--transition-normal);
}

.feature-card:nth-child(1) .fa-solid,
.feature-card:nth-child(1) .fas {
    color: #4a90d9;
}

.feature-card:nth-child(2) .fa-solid,
.feature-card:nth-child(2) .fas {
    color: #6b5b95;
}

.feature-card:nth-child(3) .fa-solid,
.feature-card:nth-child(3) .fas {
    color: #f5a623;
}

.feature-card:nth-child(4) .fa-solid,
.feature-card:nth-child(4) .fas {
    color: #50b3a2;
}

.feature-card:hover .fas,
.feature-card:hover .fa-solid,
.feature-card:hover i {
    transform: scale(1.1);
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-3);
    color: var(--text-primary);
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin: 0;
    line-height: 1.6;
}

/* ===== FOOTER ===== */
.social-footer {
    padding: var(--space-12) var(--space-6);
    text-align: center;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--primary-50) 100%);
    border-top: 1px solid var(--gray-200);
}

.social-footer h2 {
    margin-bottom: var(--space-6);
    color: var(--primary-800);
    font-size: 1.5rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: var(--space-6);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    font-size: 1.5rem;
    color: var(--primary-color);
    background-color: var(--bg-primary);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.social-links a:hover {
    color: white;
    background-color: var(--primary-color);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

/* ===== EXERCISE LIST (Lycee Page) ===== */
#section-selection {
    margin-bottom: var(--space-8);
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
    justify-content: center;
}

#exercise-list ul {
    list-style: none;
    padding: 0;
    text-align: right;
}

#exercise-list li {
    background-color: var(--bg-secondary);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-4);
    padding: var(--space-4) var(--space-5);
    transition: all var(--transition-fast);
}

#exercise-list li:hover {
    background-color: var(--primary-light);
    border-color: var(--primary-200);
    transform: translateX(-4px);
}

#exercise-list a {
    font-weight: 600;
    color: var(--primary-color);
    text-decoration: none;
}

#exercise-list a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* ===== LOADING INDICATOR ===== */
#loading-indicator {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 9999;
    display: none;
    text-align: center;
    padding: var(--space-8);
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
}

#loading-indicator .fa-spinner {
    color: var(--primary-color);
}

#loading-indicator p {
    margin-top: var(--space-4);
    color: var(--text-secondary);
}

/* ===== UNACCESSIBLE INDICATOR ===== */
.unaccessible-indicator {
    position: fixed;
    background-color: var(--gray-800);
    color: white;
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    z-index: 10000;
    pointer-events: none;
    white-space: nowrap;
    transform: translate(-50%, -100%);
    opacity: 0;
    transition: opacity var(--transition-fast);
    box-shadow: var(--shadow-lg);
}

.unaccessible-indicator.visible {
    opacity: 1;
}

/* ===== ALERTS ===== */
.alert {
    padding: var(--space-4);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-4);
    font-size: 0.9rem;
}

.alert-error {
    background-color: var(--error-light);
    color: #b91c1c;
    border: 1px solid #fecaca;
}

.alert-success {
    background-color: var(--success-light);
    color: #047857;
    border: 1px solid #a7f3d0;
}

.alert-warning {
    background-color: var(--warning-light);
    color: #92400e;
    border: 1px solid #fde68a;
}

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

/* Tablet */
@media (max-width: 992px) {
    h1 {
        font-size: 2.25rem;
    }

    h2 {
        font-size: 1.75rem;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-content p {
        font-size: 1.1rem;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-6);
    }
}

/* Mobile */
@media (max-width: 768px) {
    :root {
        --space-6: 1rem;
        --space-8: 1.5rem;
        --space-12: 2rem;
        --space-16: 3rem;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    /* Mobile Navigation */
    .main-nav {
        flex-direction: column;
        align-items: center;
    }

    .nav-toggle {
        display: block;
        align-self: flex-start;
        margin-left: 1rem;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        width: 100%;
        text-align: center;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--bg-primary);
        padding: var(--space-4);
        box-shadow: var(--shadow-lg);
        border-top: 1px solid var(--gray-200);
        gap: var(--space-1);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        width: 100%;
        margin: 0.5rem 0;
    }

    .nav-links a {
        width: 100%;
        justify-content: center;
        padding: var(--space-3) var(--space-4);
        display: block;
        font-size: 1rem;
    }

    /* Mobile Hero */
    .hero {
        min-height: auto;
        padding: var(--space-12) var(--space-4);
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

    /* Mobile Grid */
    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--space-4);
    }

    .feature-card {
        padding: var(--space-6);
    }

    /* Mobile Buttons */
    .btn {
        width: 100%;
        justify-content: center;
    }

    .btn-sm {
        width: auto;
    }

    /* Mobile Social Links */
    .social-links {
        gap: var(--space-4);
    }

    .social-links a {
        width: 44px;
        height: 44px;
        font-size: 1.25rem;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    h1 {
        font-size: 1.75rem;
    }

    .hero-content h1 {
        font-size: 1.75rem;
    }

    .feature-card .fas,
    .feature-card .fa-solid,
    .feature-card i {
        font-size: 2.5rem;
    }

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

/* ===== UTILITY CLASSES ===== */
.text-center {
    text-align: center;
}

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

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

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

.mt-4 {
    margin-top: var(--space-4);
}

.mb-4 {
    margin-bottom: var(--space-4);
}

.my-4 {
    margin-top: var(--space-4);
    margin-bottom: var(--space-4);
}

.p-4 {
    padding: var(--space-4);
}

.px-4 {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
}

.py-4 {
    padding-top: var(--space-4);
    padding-bottom: var(--space-4);
}

.rounded {
    border-radius: var(--radius-md);
}

.shadow {
    box-shadow: var(--shadow-md);
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== DARK MODE ===== */

/* Smooth theme transition */
body,
body *,
body *::before,
body *::after {
    transition: 
        background-color 0.3s ease,
        background 0.3s ease,
        color 0.3s ease,
        border-color 0.3s ease,
        box-shadow 0.3s ease,
        fill 0.3s ease,
        stroke 0.3s ease;
}

/* Exclude elements that shouldn't transition */
body .no-transition,
body .no-transition *,
body input,
body textarea,
body select,
body button:active,
body a:active {
    transition: none !important;
}

body.dark-mode {
    --text-primary: #f3f4f6;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    --text-light: #6b7280;
    
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    
    --gray-50: #1f2937;
    --gray-100: #374151;
    --gray-200: #4b5563;
    --gray-300: #6b7280;
    --gray-700: #d1d5db;
    --gray-800: #e5e7eb;
    --gray-900: #f9fafb;
    
    --primary-light: #312e81;
    --primary-50: #1e1b4b;
    --primary-100: #312e81;
    --primary-800: #a5b4fc;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
    
    color-scheme: dark;
}

/* Dark Mode - Body */
body.dark-mode {
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

/* Dark Mode - Typography */
body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode h4,
body.dark-mode h5,
body.dark-mode h6 {
    color: var(--text-primary);
}

body.dark-mode p {
    color: var(--text-secondary);
}

body.dark-mode a {
    color: white;
}

body.dark-mode a:hover {
    text-shadow: 0 0 5px rgba(255, 255, 255, 0.2);
}

/* Dark Mode - Hero Section */
body.dark-mode .hero {
    background: linear-gradient(135deg, #1e1b4b 0%, #111827 50%, #312e81 100%);
}

body.dark-mode .hero::before {
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    opacity: 0.25;
}

body.dark-mode .hero::after {
    background: linear-gradient(135deg, #f59e0b, #6366f1);
    opacity: 0.2;
}

body.dark-mode .hero-pattern {
    background-image: 
        linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
}

body.dark-mode .hero-badge {
    background: rgba(99, 102, 241, 0.2);
    border-color: rgba(99, 102, 241, 0.3);
    color: #a5b4fc;
}

body.dark-mode .hero-badge i {
    color: #818cf8;
}

body.dark-mode .hero-content h1 {
    color: #c7d2fe;
}

body.dark-mode .hero-content p {
    color: #a5b4fc;
}

body.dark-mode .hero-btn-primary {
    background: linear-gradient(135deg, #6366f1, #4f46e5);
    box-shadow: 0 8px 20px -6px rgba(99, 102, 241, 0.4);
}

body.dark-mode .hero-btn-primary:hover {
    box-shadow: 0 12px 28px -6px rgba(99, 102, 241, 0.5);
}

body.dark-mode .hero-btn-secondary {
    background: var(--bg-secondary);
    color: #a5b4fc;
    border-color: #4b5563;
}

body.dark-mode .hero-btn-secondary:hover {
    background: #374151;
    border-color: #6366f1;
    color: #c7d2fe;
}

/* Dark Mode - Featured Content */
body.dark-mode .featured-content {
    background-color: var(--bg-primary);
}

body.dark-mode .featured-content h2 {
    color: #c7d2fe;
}

/* Dark Mode - Feature Cards */
body.dark-mode .feature-card {
    background-color: var(--bg-secondary);
    border-color: #374151;
}

body.dark-mode .feature-card:hover {
    border-color: #6366f1;
    box-shadow: 0 20px 40px rgba(99, 102, 241, 0.15);
}

body.dark-mode .feature-card h3 {
    color: var(--text-primary);
}

body.dark-mode .feature-card p {
    color: var(--text-muted);
}

body.dark-mode .feature-card:nth-child(1) .fa-solid,
body.dark-mode .feature-card:nth-child(1) .fas {
    color: #60a5fa;
}

body.dark-mode .feature-card:nth-child(2) .fa-solid,
body.dark-mode .feature-card:nth-child(2) .fas {
    color: #a78bfa;
}

body.dark-mode .feature-card:nth-child(3) .fa-solid,
body.dark-mode .feature-card:nth-child(3) .fas {
    color: #fbbf24;
}

body.dark-mode .feature-card:nth-child(4) .fa-solid,
body.dark-mode .feature-card:nth-child(4) .fas {
    color: #34d399;
}

body.dark-mode .feature-card:nth-child(5) .fa-solid,
body.dark-mode .feature-card:nth-child(5) .fas {
    color: #f472b6;
}

/* Dark Mode - Footer */
body.dark-mode .social-footer {
    background: linear-gradient(135deg, #1f2937 0%, #1e1b4b 100%);
    border-top-color: #374151;
}

body.dark-mode .social-footer h2 {
    color: #c7d2fe;
}

body.dark-mode .social-links a {
    background-color: var(--bg-secondary);
    color: #818cf8;
    box-shadow: var(--shadow-md);
}

body.dark-mode .social-links a:hover {
    background-color: #6366f1;
    color: white;
}

/* Dark Mode - Buttons */
body.dark-mode .btn {
    box-shadow: var(--shadow-md);
}

body.dark-mode .btn-secondary {
    background-color: var(--bg-secondary);
    color: #818cf8;
    border-color: #6366f1;
}

body.dark-mode .btn-secondary:hover {
    background-color: #312e81;
    color: #a5b4fc;
}

body.dark-mode .btn-outline {
    background-color: transparent;
    color: var(--text-primary);
    border-color: #4b5563;
}

body.dark-mode .btn-outline:hover {
    background-color: var(--bg-tertiary);
    border-color: #6b7280;
}

/* Dark Mode - Loading Indicator */
body.dark-mode #loading-indicator {
    background-color: var(--bg-secondary);
    box-shadow: var(--shadow-xl);
}

body.dark-mode #loading-indicator .fa-spinner {
    color: #818cf8;
}

body.dark-mode #loading-indicator p {
    color: var(--text-secondary);
}

/* Dark Mode - Alerts */
body.dark-mode .alert-error {
    background-color: #450a0a;
    color: #fca5a5;
    border-color: #7f1d1d;
}

body.dark-mode .alert-success {
    background-color: #022c22;
    color: #6ee7b7;
    border-color: #065f46;
}

body.dark-mode .alert-warning {
    background-color: #451a03;
    color: #fcd34d;
    border-color: #78350f;
}

/* Dark Mode - Exercise List */
body.dark-mode #exercise-list li {
    background-color: var(--bg-secondary);
    border-color: #374151;
}

body.dark-mode #exercise-list li:hover {
    background-color: #312e81;
    border-color: #6366f1;
}

body.dark-mode #exercise-list a {
    color: #818cf8;
}

body.dark-mode #exercise-list a:hover {
    color: #a5b4fc;
}

/* Dark Mode - Unaccessible Indicator */
body.dark-mode .unaccessible-indicator {
    background-color: #e5e7eb;
    color: #1f2937;
}

/* Dark Mode - Scrollbar */
body.dark-mode::-webkit-scrollbar {
    width: 10px;
}

body.dark-mode::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

body.dark-mode::-webkit-scrollbar-thumb {
    background: #4b5563;
    border-radius: 5px;
}

body.dark-mode::-webkit-scrollbar-thumb:hover {
    background: #6b7280;
}

/* Dark Mode - Selection */
body.dark-mode ::selection {
    background-color: #6366f1;
    color: white;
}