/* TikTok Dark Theme - Main Styles */

:root {
    /* Color Palette */
    --bg-primary: #0f1419;
    --bg-secondary: #1a1f2e;
    --bg-card: #2a3048;
    --bg-input: #1e2332;
    
    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #a0aec0;
    --text-muted: #718096;
    
    /* Accent Colors */
    --accent-primary: #00d4aa;
    --accent-secondary: #00b894;
    --accent-purple: #8b5cf6;
    --accent-blue: #3b82f6;
    --accent-green: #10b981;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #00d4aa 0%, #00b894 100%);
    --gradient-purple: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%);
    --gradient-blue: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    --gradient-green: linear-gradient(135deg, #10b981 0%, #059669 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
}

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

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

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

/* Header */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-sm) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.donate-btn {
    background: var(--gradient-primary);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

/* Hero Section */
.hero {
    padding: var(--spacing-2xl) 0;
    text-align: center;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

/* Download Form */
.download-form {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-xl);
    margin-bottom: var(--spacing-xl);
}

.form-group {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.form-input {
    flex: 1;
    background: var(--bg-input);
    border: 2px solid transparent;
    border-radius: var(--radius-lg);
    padding: 1rem 1.5rem;
    color: var(--text-primary);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

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

.btn {
    padding: 1rem 2rem;
    border: none;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

.btn-secondary {
    background: var(--bg-input);
    color: var(--text-primary);
    border: 2px solid rgba(255, 255, 255, 0.1);
}

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

/* Features Section */
.features {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-secondary);
}

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

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

.section-title h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.section-title p {
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

.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: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

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

/* Video Cards */
.video-card {
    text-align: left;
    padding: 0;
    overflow: hidden;
}

.video-thumbnail {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--bg-input);
}

.thumbnail-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.video-card:hover .thumbnail-image {
    transform: scale(1.05);
}

.thumbnail-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    color: white;
}

.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.video-card:hover .video-overlay {
    opacity: 1;
}

.play-button {
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--bg-primary);
    transition: transform 0.3s ease;
}

.play-button:hover {
    transform: scale(1.1);
}

.video-info {
    padding: var(--spacing-lg);
}

.video-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    line-height: 1.4;
}

.video-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    font-size: 0.875rem;
}

.username {
    color: var(--accent-primary);
    font-weight: 500;
}

.downloads {
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
}

.view-original-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--gradient-primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.875rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.view-original-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--text-secondary);
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
}

.empty-state h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.empty-state p {
    font-size: 1.125rem;
    max-width: 400px;
    margin: 0 auto;
}

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

.feature-icon.primary { background: var(--gradient-primary); }
.feature-icon.purple { background: var(--gradient-purple); }
.feature-icon.blue { background: var(--gradient-blue); }

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

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

/* How-to Section */
.how-to {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-primary);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.step-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    text-align: center;
    transition: transform 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.step-card:hover {
    transform: translateY(-3px);
}

.step-number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
}

.step-number.primary { background: var(--gradient-primary); }
.step-number.purple { background: var(--gradient-purple); }
.step-number.blue { background: var(--gradient-blue); }

/* Products Section */
.products {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-secondary);
}

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

.product-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

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

.product-header {
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
}

.product-header.primary { background: var(--gradient-primary); }
.product-header.purple { background: var(--gradient-purple); }
.product-header.blue { background: var(--gradient-blue); }

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

.product-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.product-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.product-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: var(--spacing-md);
}

.product-btn {
    width: 100%;
    justify-content: center;
}

/* Blog Section */
.blog {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-primary);
}

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

.blog-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.blog-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.blog-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.blog-excerpt {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.blog-link {
    color: var(--accent-primary);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.blog-link:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    padding: var(--spacing-xl) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

.footer-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.footer-link {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-copyright {
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

/* Responsive Design */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .nav {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .form-group {
        flex-direction: column;
    }
    
    .features-grid {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        gap: var(--spacing-md);
    }
    
    .steps-grid,
    .products-grid,
    .blog-grid {
        grid-template-columns: 1fr;
    }
    
    .video-thumbnail {
        height: 180px;
    }
    
    .video-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .footer-links {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .section-title h2 {
        font-size: 2rem;
    }
    
    .download-form {
        padding: var(--spacing-md);
    }
    
    .feature-card,
    .step-card,
    .product-card,
    .blog-card {
        padding: var(--spacing-md);
    }
    
    .video-thumbnail {
        height: 160px;
    }
    
    .video-info {
        padding: var(--spacing-md);
    }
    
    .video-title {
        font-size: 1rem;
    }
    
    .view-original-btn {
        padding: 0.5rem 1rem;
        font-size: 0.8rem;
    }
}

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

.spinner {
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-top: 2px solid var(--accent-primary);
    border-radius: 50%;
    width: 20px;
    height: 20px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Success/Error States */
.success {
    color: var(--accent-green);
}

.error {
    color: #ef4444;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

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

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

.slide-in-up {
    animation: slideInUp 0.8s ease-out;
}

.scale-in {
    animation: scaleIn 0.5s ease-out;
}

/* Staggered animations for video cards */
.video-card {
    animation: slideInUp 0.6s ease-out;
    animation-fill-mode: both;
}

.video-card:nth-child(1) { animation-delay: 0.1s; }
.video-card:nth-child(2) { animation-delay: 0.2s; }
.video-card:nth-child(3) { animation-delay: 0.3s; }
.video-card:nth-child(4) { animation-delay: 0.4s; }
.video-card:nth-child(5) { animation-delay: 0.5s; }
.video-card:nth-child(6) { animation-delay: 0.6s; }
.video-card:nth-child(7) { animation-delay: 0.7s; }
.video-card:nth-child(8) { animation-delay: 0.8s; }

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}