/* RSK World Theme - Static Demo CSS */
/* Created by: Molla Samser | Designer & Tester: Rima Khatun */

/* ===== CSS Variables ===== */
:root {
    /* Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #22d3ee;
    --secondary-dark: #06b6d4;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    
    /* Text Colors */
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --text-white: #ffffff;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #1f2937;
    --bg-darker: #111827;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #818cf8 100%);
    --gradient-secondary: linear-gradient(135deg, #22d3ee 0%, #06b6d4 100%);
    --gradient-accent: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    --gradient-dark: linear-gradient(135deg, #1f2937 0%, #111827 100%);
    
    /* Typography */
    --font-primary: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Font Sizes */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* 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);
    
    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
}

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

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

ul, ol {
    list-style: none;
}

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--text-6xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--text-base);
    font-weight: 500;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.1);
    transition: left var(--transition-normal);
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--text-white);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: var(--gradient-secondary);
    color: var(--text-white);
    box-shadow: var(--shadow-md);
}

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

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

.btn-outline:hover {
    background: var(--primary-color);
    color: var(--text-white);
    transform: translateY(-2px);
}

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.navbar {
    padding: var(--spacing-md) 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand .logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--text-primary);
}

.nav-brand .logo img {
    width: 40px;
    height: 40px;
}

.nav-menu {
    display: flex;
}

.nav-list {
    display: flex;
    gap: var(--spacing-xl);
}

.nav-link {
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-normal);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    transition: all var(--transition-normal);
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: var(--spacing-3xl) 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="%23e2e8f0" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

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

.hero-title {
    font-size: var(--text-5xl);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: var(--text-xl);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    font-weight: 500;
}

.hero-description {
    font-size: var(--text-lg);
    margin-bottom: var(--spacing-xl);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
}

.hero-illustration {
    position: relative;
}

.code-editor {
    background: var(--bg-darker);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    transform: perspective(1000px) rotateY(-5deg);
    transition: transform var(--transition-normal);
}

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

.editor-header {
    background: var(--bg-dark);
    padding: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.editor-dots {
    display: flex;
    gap: var(--spacing-xs);
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot.red { background: #ef4444; }
.dot.yellow { background: #f59e0b; }
.dot.green { background: #10b981; }

.editor-title {
    color: var(--text-light);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
}

.editor-content {
    padding: var(--spacing-lg);
}

.editor-content pre {
    margin: 0;
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    line-height: 1.5;
    color: #e2e8f0;
}

/* ===== Section Styles ===== */
section {
    padding: var(--spacing-3xl) 0;
}

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

.section-title {
    font-size: var(--text-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

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

/* ===== Theme Showcase Section ===== */
.theme-showcase {
    padding: 80px 0;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    position: relative;
    overflow: hidden;
}

.theme-showcase::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    pointer-events: none;
}

.theme-preview {
    text-align: center;
    position: relative;
}

.theme-screenshot {
    position: relative;
    display: inline-block;
    max-width: 100%;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.theme-screenshot:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.2);
}

.theme-screenshot img {
    width: 100%;
    height: auto;
    max-height: 500px;
    object-fit: cover;
    display: block;
}

.theme-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9), transparent);
    color: white;
    padding: 30px 20px 20px;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.theme-screenshot:hover .theme-overlay {
    transform: translateY(0);
}

.theme-overlay h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: white;
}

.theme-overlay p {
    font-size: 0.9rem;
    margin-bottom: 15px;
    opacity: 0.9;
}

.theme-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
}

.theme-badges .badge {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* ===== Features Section ===== */
.features {
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.feature-card {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

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

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-2xl);
    color: var(--text-white);
}

.feature-title {
    font-size: var(--text-xl);
    margin-bottom: var(--spacing-md);
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===== Courses Section ===== */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.course-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.course-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.course-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-normal);
}

.course-card:hover .course-image img {
    transform: scale(1.05);
}

.course-level {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: var(--accent-color);
    color: var(--text-white);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-lg);
    font-size: var(--text-xs);
    font-weight: 600;
    text-transform: uppercase;
}

.course-content {
    padding: var(--spacing-xl);
}

.course-title {
    font-size: var(--text-xl);
    margin-bottom: var(--spacing-md);
}

.course-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.course-meta {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    font-size: var(--text-sm);
    color: var(--text-secondary);
}

.course-meta span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.course-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.course-price {
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--success-color);
}

/* ===== Resources Section ===== */
.resources {
    background: var(--bg-secondary);
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
}

.resource-card {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all var(--transition-normal);
    position: relative;
}

.resource-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.resource-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto var(--spacing-lg);
    background: var(--gradient-secondary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-xl);
    color: var(--text-white);
}

.resource-title {
    font-size: var(--text-lg);
    margin-bottom: var(--spacing-md);
}

.resource-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.resource-link {
    color: var(--primary-color);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: gap var(--transition-normal);
}

.resource-link:hover {
    gap: var(--spacing-md);
}

/* ===== Stats Section ===== */
.stats {
    background: var(--gradient-dark);
    color: var(--text-white);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
}

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

.stat-number {
    font-size: var(--text-4xl);
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: var(--text-lg);
    opacity: 0.9;
}

/* ===== About Section ===== */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.about-text h3 {
    font-size: var(--text-2xl);
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
}

.team-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.team-member h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.role {
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.about-image img {
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

/* ===== Contact Section ===== */
.contact {
    background: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    flex-shrink: 0;
}

.contact-details h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.contact-form {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid #e5e7eb;
    border-radius: var(--radius-lg);
    font-family: inherit;
    font-size: var(--text-base);
    transition: border-color var(--transition-normal);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-darker);
    color: var(--text-white);
    padding: var(--spacing-3xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.footer-logo img {
    width: 40px;
    height: 40px;
}

.footer-logo h3 {
    margin: 0;
    color: var(--text-white);
}

.footer-description {
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

.footer-title {
    font-size: var(--text-lg);
    margin-bottom: var(--spacing-lg);
    color: var(--text-white);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-links a {
    color: var(--text-light);
    transition: color var(--transition-fast);
}

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

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    transition: all var(--transition-normal);
}

.social-link:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
}

.newsletter-form {
    display: flex;
    gap: var(--spacing-sm);
}

.newsletter-form input {
    flex: 1;
    padding: var(--spacing-md);
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    color: var(--text-white);
}

.newsletter-form input::placeholder {
    color: var(--text-light);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: var(--text-sm);
    opacity: 0.7;
}

.footer-bottom a {
    color: var(--text-light);
}

/* ===== Back to Top Button ===== */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    border: none;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 999;
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

/* ===== Loading States ===== */
.loading {
    opacity: 0.7;
    pointer-events: none;
}

/* ===== Accessibility ===== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus States */
.btn:focus,
input:focus,
textarea:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}