/* ===================================
   CSS VARIABLES (Color Palette)
   =================================== */
:root {
    /* Primary Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    
    /* Secondary Colors */
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    
    /* Neutral Colors */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-card: #ffffff;
    
    /* Borders & Shadows */
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 40px -5px rgba(0, 0, 0, 0.12);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: 1.6;
    font-size: 16px;
    overflow-x: hidden;
}

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

/* ===================================
   TYPOGRAPHY
   =================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 {
    font-size: 3.5rem;
    font-weight: 800;
}

h2 {
    font-size: 2.5rem;
}

h3 {
    font-size: 1.5rem;
}

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

/* ===================================
   HEADER & NAVIGATION
   =================================== */
.header {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.95);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    font-size: 1.8rem;
}

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

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

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

/* Language Selector */
.language-selector {
    position: relative;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.lang-btn:hover {
    border-color: var(--primary-color);
    background-color: var(--bg-card);
}

.lang-btn .fa-globe {
    color: var(--primary-color);
}

.lang-btn .fa-chevron-down {
    font-size: 0.7rem;
    transition: transform var(--transition-base);
}

.lang-btn:hover .fa-chevron-down {
    transform: rotate(180deg);
}

.current-lang {
    font-weight: 600;
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    min-width: 180px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-base);
    z-index: 1000;
}

.lang-dropdown.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-primary);
    text-decoration: none;
    transition: background-color var(--transition-base);
    font-weight: 500;
}

.lang-option:first-child {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.lang-option:last-child {
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.lang-option:hover {
    background-color: var(--bg-secondary);
    color: var(--primary-color);
}

.lang-option.active {
    background-color: var(--primary-light);
    color: white;
}

.lang-option.active:hover {
    background-color: var(--primary-color);
}

.lang-option .flag {
    font-size: 1.25rem;
}

.github-link {
    padding: var(--spacing-xs) var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

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

/* ===================================
   HERO SECTION
   =================================== */
.hero {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

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

.hero-text {
    animation: fadeInUp 0.8s ease;
}

.hero-title {
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-secondary);
}

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

.browser-support {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    color: var(--text-light);
    font-size: 0.9rem;
}

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

.browsers a {
    text-decoration: none;
}

.browsers i {
    font-size: 1.5rem;
    color: var(--text-secondary);
    transition: color var(--transition-base);
}

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

.hero-image {
    animation: fadeInRight 0.8s ease;
}

.screenshot-placeholder {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    transition: transform var(--transition-slow);
}

.screenshot-placeholder:hover {
    transform: translateY(-8px);
}

.screenshot-placeholder img {
    width: 100%;
    height: auto;
    display: block;
}

/* ===================================
   BUTTONS
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background-color: var(--bg-card);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

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

.btn-large {
    padding: 1.125rem 2.5rem;
    font-size: 1.125rem;
}

/* ===================================
   FEATURES SECTION
   =================================== */
.features {
    padding: var(--spacing-2xl) 0;
    background-color: var(--bg-primary);
}

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

.section-header h2 {
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.feature-card {
    background-color: var(--bg-card);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.feature-icon i {
    font-size: 1.75rem;
    color: white;
}

.feature-card h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

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

/* ===================================
   HOW IT WORKS SECTION
   =================================== */
.how-it-works {
    padding: var(--spacing-2xl) 0;
    background-color: var(--bg-secondary);
}

.steps {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.step {
    flex: 1;
    text-align: center;
    padding: var(--spacing-lg);
    background-color: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0 auto var(--spacing-md);
}

.step h3 {
    margin-bottom: var(--spacing-xs);
}

.step p {
    font-size: 0.95rem;
}

.step-arrow {
    font-size: 2rem;
    color: var(--primary-color);
    font-weight: 700;
}

/* Feature Blocks in How It Works */
.feature-blocks {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
}

.feature-block {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.feature-block-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.feature-block-header i {
    font-size: 2.5rem;
    color: var(--primary-color);
}

.feature-block-header.youtube i {
    color: #ff0000;
}

.feature-block-header.amazon i {
    color: #ff9900;
}

.feature-block-header h3 {
    font-size: 1.5rem;
    margin: 0;
}

.feature-block-header p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.feature-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.feature-item i {
    color: var(--primary-color);
    font-size: 1.1rem;
    margin-top: 2px;
    flex-shrink: 0;
}

.feature-item div {
    flex: 1;
}

.feature-item strong {
    display: block;
    font-size: 0.95rem;
    margin-bottom: 2px;
}

.feature-item span {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

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

@media (max-width: 768px) {
    .feature-list {
        grid-template-columns: 1fr;
    }
    
    .feature-block-header {
        flex-direction: column;
        text-align: center;
    }
}

/* ===================================
   PRIVACY SECTION
   =================================== */
.privacy {
    padding: var(--spacing-2xl) 0;
    background-color: var(--bg-primary);
}

.privacy-content {
    display: flex;
    gap: var(--spacing-xl);
    align-items: center;
    padding: var(--spacing-xl);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-xl);
    border: 2px solid var(--border-color);
}

.privacy-icon {
    flex-shrink: 0;
}

.privacy-icon i {
    font-size: 5rem;
    color: var(--primary-color);
}

.privacy-text h2 {
    margin-bottom: var(--spacing-md);
}

.privacy-text p {
    margin-bottom: var(--spacing-md);
    font-size: 1.05rem;
}

/* ===================================
   CTA SECTION
   =================================== */
.cta {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

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

.cta-content h2 {
    color: white;
    margin-bottom: var(--spacing-sm);
}

.cta-content p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

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

.cta-buttons .btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

/* ===================================
   FOOTER
   =================================== */
.footer {
    background-color: var(--text-primary);
    color: white;
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.footer-brand {
    flex: 1;
    max-width: 300px;
}

.footer-brand .logo {
    color: white;
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.7);
}

.footer-links {
    display: flex;
    gap: var(--spacing-2xl);
}

.footer-column h4 {
    color: white;
    margin-bottom: var(--spacing-md);
    font-size: 1rem;
}

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

.footer-column ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-column a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-base);
}

.footer-column a:hover {
    color: white;
}

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

.social-links a {
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
    transition: all var(--transition-base);
}

.social-links a:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
}

.footer-bottom i.fa-heart {
    color: var(--accent-color);
}

/* ===================================
   ANIMATIONS
   =================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* ===================================
   RESPONSIVE DESIGN
   =================================== */
@media (max-width: 1024px) {
    h1 {
        font-size: 2.75rem;
    }
    
    h2 {
        font-size: 2rem;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .hero-image {
        order: -1;
    }
    
    .steps {
        flex-direction: column;
    }
    
    .step-arrow {
        transform: rotate(90deg);
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-lg);
    }
    
    .footer-brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 768px) {
    h1 {
        font-size: 2.25rem;
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    .hero-subtitle {
        font-size: 1.05rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .cta-buttons .btn {
        width: 100%;
        max-width: 400px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .privacy-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .footer-brand {
        max-width: 100%;
    }
    
    .footer-links {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .nav-links {
        gap: var(--spacing-sm);
    }
    
    .nav-links a span {
        display: none;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    h1 {
        font-size: 1.875rem;
    }
    
    .hero {
        padding: var(--spacing-xl) 0;
    }
    
    .features,
    .how-it-works,
    .privacy,
    .cta {
        padding: var(--spacing-xl) 0;
    }
    
    .logo span {
        font-size: 1.125rem;
    }
    
    .btn {
        padding: 0.75rem 1.25rem;
        font-size: 0.9rem;
    }
}