/* ============================================
   متغیرهای CSS و تنظیمات پایه
   ============================================ */
:root {
    /* رنگ‌های اصلی */
    --primary: #3776ab;
    --primary-dark: #2b5e8c;
    --primary-light: #4a8bc2;
    --accent: #ffd43b;
    --accent-dark: #f9c726;

    /* رنگ‌های خنثی - حالت روشن */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-code: #0d1117;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #64748b;
    --border: #e2e8f0;
    --border-strong: #cbd5e1;

    /* سایه‌ها */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* فاصله‌گذاری */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;

    /* شعاع‌ها */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;

    /* انتقال‌ها */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* حالت تاریک */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-code: #0d1117;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    --border: #334155;
    --border-strong: #475569;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.4), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.5), 0 8px 10px -6px rgb(0 0 0 / 0.4);
}

/* ============================================
   ریست و استایل‌های پایه
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: 'Vazirmatn', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    direction: rtl;
    transition: background-color var(--transition-normal), color var(--transition-normal);
    overflow-x: hidden;
}

/* اسکرول‌بار سفارشی */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-strong);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

/* ============================================
   Utility Classes
   ============================================ */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   Progress Bar
   ============================================ */
.progress-bar {
    position: fixed;
    top: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
    width: 0%;
    z-index: 1000;
    transition: width 100ms ease-out;
}

/* ============================================
   Header
   ============================================ */
.header {
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(12px);
    background: rgba(255, 255, 255, 0.8);
    z-index: 100;
    transition: all var(--transition-normal);
}

[data-theme="dark"] .header {
    background: rgba(15, 23, 42, 0.8);
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
}

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

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

.nav-desktop {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.nav-desktop a {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

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

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--bg-secondary);
    color: var(--primary);
    border-color: var(--primary);
}

.sun-icon {
    display: none;
}

[data-theme="dark"] .sun-icon {
    display: block;
}

[data-theme="dark"] .moon-icon {
    display: none;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    width: 40px;
    height: 40px;
    cursor: pointer;
    flex-direction: column;
    justify-content: center;
    gap: 4px;
    padding: 8px;
}

.mobile-menu-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    padding: var(--spacing-3xl) 0;
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: radial-gradient(circle at 25% 25%, rgba(55, 118, 171, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, rgba(255, 212, 59, 0.08) 0%, transparent 50%);
    pointer-events: none;
}

.hero .container {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    font-weight: 500;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: #10b981;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

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

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
    max-width: 540px;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-2xl);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all var(--transition-fast);
    font-family: inherit;
}

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

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

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

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

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
}

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

.hero-stats {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1;
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--border);
}

/* Code Window */
.hero-visual {
    position: relative;
}

.code-window {
    background: var(--bg-code);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transform: perspective(1000px) rotateY(-5deg) rotateX(2deg);
    transition: transform var(--transition-slow);
}

.code-window:hover {
    transform: perspective(1000px) rotateY(0deg) rotateX(0deg);
}

.code-header {
    background: #161b22;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.code-dots {
    display: flex;
    gap: 6px;
}

.code-dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #2d333b;
}

.code-dots span:nth-child(1) {
    background: #ff5f56;
}

.code-dots span:nth-child(2) {
    background: #ffbd2e;
}

.code-dots span:nth-child(3) {
    background: #27c93f;
}

.code-title {
    color: #8b949e;
    font-size: 0.875rem;
    font-family: 'JetBrains Mono', monospace;
}

.code-block {
    padding: var(--spacing-lg);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9375rem;
    line-height: 1.6;
    overflow-x: auto;
    direction: ltr;
    text-align: left;
}

.code-block code {
    color: #e6edf3;
}

.code-block .prompt {
    color: #7ee787;
}

.code-block .keyword {
    color: #ff7b72;
}

.code-block .function {
    color: #d2a8ff;
}

.code-block .string {
    color: #a5d6ff;
}

.code-block .builtin {
    color: #ffa657;
}

.code-block .output {
    color: #8b949e;
}

/* ============================================
   Features Section
   ============================================ */
.features {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.feature-card code {
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875em;
    color: var(--primary);
}

/* ============================================
   Chapters Section
   ============================================ */
.chapters {
    padding: var(--spacing-3xl) 0;
}

.chapters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

.chapter-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    text-decoration: none;
    color: inherit;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.chapter-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 4px;
    height: 100%;
    background: var(--primary);
    transform: scaleY(0);
    transition: transform var(--transition-normal);
    transform-origin: top;
}

.chapter-card:hover {
    transform: translateX(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
}

.chapter-card:hover::before {
    transform: scaleY(1);
}

.chapter-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary);
    opacity: 0.3;
    min-width: 60px;
    text-align: center;
    font-family: 'JetBrains Mono', monospace;
}

.chapter-content {
    flex: 1;
}

.chapter-content h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.chapter-content p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.chapter-content code {
    background: var(--bg-tertiary);
    padding: 1px 4px;
    border-radius: 3px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85em;
    color: var(--primary);
}

.chapter-arrow {
    color: var(--text-tertiary);
    transition: transform var(--transition-fast);
}

.chapter-card:hover .chapter-arrow {
    transform: translateX(-4px);
    color: var(--primary);
}

/* ============================================
   About Section
   ============================================ */
.about {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-secondary);
}

.about-card {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-3xl);
    color: white;
    position: relative;
    overflow: hidden;
}

.about-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.about-content {
    position: relative;
    z-index: 1;
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.about-content h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
}

.about-content p {
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    opacity: 0.95;
}

.about-content strong {
    color: var(--accent);
}

.about-links {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-top: var(--spacing-xl);
    flex-wrap: wrap;
}

.about-links .btn {
    background: white;
    color: var(--primary);
}

.about-links .btn-outline {
    background: transparent;
    color: white;
    border-color: white;
}

.about-links .btn-outline:hover {
    background: white;
    color: var(--primary);
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.footer-logo img {
    width: 28px;
    height: 28px;
}

.footer-section p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.footer-section h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.footer-bottom a {
    color: var(--primary);
    text-decoration: none;
}

.footer-bottom a:hover {
    text-decoration: underline;
}

/* ============================================
   Search Modal
   ============================================ */
.search-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    display: none;
    align-items: flex-start;
    justify-content: center;
    padding-top: 10vh;
}

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

.search-container {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    width: 90%;
    max-width: 600px;
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    border: 1px solid var(--border);
}

.search-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
}

.search-header input {
    flex: 1;
    background: none;
    border: none;
    outline: none;
    font-size: 1rem;
    color: var(--text-primary);
    font-family: inherit;
}

.search-header kbd {
    background: var(--bg-tertiary);
    padding: 2px 8px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

.search-results {
    max-height: 400px;
    overflow-y: auto;
    padding: var(--spacing-sm);
}

.search-result-item {
    display: block;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: inherit;
    transition: background var(--transition-fast);
}

.search-result-item:hover {
    background: var(--bg-secondary);
}

.search-result-item h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--primary);
}

.search-result-item p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ============================================
   Back to Top
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 30px;
    left: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 90;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }

    .hero-visual {
        max-width: 600px;
        margin: 0 auto;
    }

    .code-window {
        transform: none;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        --spacing-3xl: 2.5rem;
    }

    .nav-desktop {
        display: none;
    }

    .mobile-menu-toggle {
        display: flex;
    }

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

    .section-title {
        font-size: 1.875rem;
    }

    .hero-stats {
        flex-wrap: wrap;
        gap: var(--spacing-md);
    }

    .stat-divider {
        display: none;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .chapters-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
    }

    .btn {
        justify-content: center;
    }

    .chapter-card {
        flex-direction: column;
        text-align: center;
        align-items: stretch;
    }

    .chapter-arrow {
        align-self: center;
        transform: rotate(-90deg);
    }

    .chapter-card:hover .chapter-arrow {
        transform: rotate(-90deg) translateY(-4px);
    }
}