@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
    /* Dark theme colors */
    --bg-primary: #0a0a0a;
    --bg-secondary: #111111;
    --bg-tertiary: #1a1a1a;
    --bg-card: #1e1e1e;
    --bg-elevated: #252525;
    
    /* Text colors */
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-tertiary: #707070;
    --text-muted: #505050;
    
    /* Accent colors */
    --accent-primary: #3b82f6;
    --accent-secondary: #8b5cf6;
    --accent-success: #10b981;
    --accent-warning: #f59e0b;
    --accent-danger: #ef4444;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    --gradient-secondary: linear-gradient(135deg, #1e40af 0%, #7c3aed 100%);
    --gradient-accent: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
    
    /* Borders and shadows */
    --border-color: #2a2a2a;
    --border-hover: #3a3a3a;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    
    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

* {
    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;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

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

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

::-webkit-scrollbar-thumb {
    background: var(--bg-elevated);
    border-radius: var(--radius-sm);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-xl);
    flex-grow: 1;
}

/* Header and title styling */
h1 {
    text-align: center;
    margin-bottom: var(--space-md);
    color: var(--text-primary);
    font-weight: 700;
    font-size: clamp(2rem, 5vw, 3rem);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    position: relative;
    letter-spacing: -0.02em;
}

h1::after {
    content: '';
    position: absolute;
    bottom: -12px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: var(--radius-sm);
}

.description {
    text-align: center;
    margin-bottom: var(--space-2xl);
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.7;
}

/* Upload container */
.upload-container {
    background: var(--bg-card);
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-2xl);
    padding: var(--space-2xl);
    text-align: center;
    margin-bottom: var(--space-xl);
    transition: all var(--transition-normal);
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
}

.upload-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-primary);
    opacity: 0;
    transition: opacity var(--transition-normal);
    z-index: 0;
}

.upload-container:hover::before,
.upload-container.dragover::before {
    opacity: 0.05;
}

.upload-container:hover,
.upload-container.dragover {
    border-color: var(--accent-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.upload-icon {
    width: 80px;
    height: 80px;
    margin-bottom: var(--space-lg);
    transition: transform var(--transition-normal);
    filter: drop-shadow(var(--shadow-md));
    position: relative;
    z-index: 1;
    opacity: 0.8;
}

.upload-container:hover .upload-icon {
    transform: scale(1.1);
    opacity: 1;
}

.upload-container p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    position: relative;
    z-index: 1;
    font-weight: 500;
}

.upload-button {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    background: var(--gradient-primary);
    color: white;
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-xl);
    margin: var(--space-lg) 0;
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
    position: relative;
    z-index: 1;
    border: none;
    text-decoration: none;
}

.upload-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    background: var(--gradient-secondary);
}

.upload-button i {
    font-size: 1.1rem;
}

.file-requirements {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    margin-top: var(--space-lg);
    position: relative;
    z-index: 1;
    font-weight: 400;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
}

.file-requirements i {
    color: var(--accent-primary);
}

/* Preview container */
.preview-container {
    background: var(--bg-card);
    border-radius: var(--radius-2xl);
    padding: var(--space-2xl);
    box-shadow: var(--shadow-xl);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
}

.preview-container h2 {
    text-align: center;
    margin-bottom: var(--space-xl);
    color: var(--text-primary);
    font-weight: 700;
    font-size: 2rem;
    position: relative;
    letter-spacing: -0.01em;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
}

.preview-container h2::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: var(--radius-sm);
}

.preview-container h2 i {
    color: var(--accent-primary);
    font-size: 1.8rem;
}

/* Custom title input */
.custom-title-input {
    margin-bottom: var(--space-xl);
}

.custom-title-input label {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    margin-bottom: var(--space-sm);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.custom-title-input label i {
    color: var(--accent-primary);
    font-size: 0.8rem;
}

.custom-title-input input {
    width: 100%;
    padding: var(--space-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-normal);
    font-family: inherit;
}

.custom-title-input input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
    background: var(--bg-tertiary);
}

/* Settings panel */
.settings-panel {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
    border: 1px solid var(--border-color);
}

.settings-title {
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.settings-title::before {
    content: '⚙️';
    font-size: 1.1rem;
    margin-right: var(--space-xs);
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
}

.setting-item {
    display: flex;
    flex-direction: column;
}

.setting-item label {
    margin-bottom: var(--space-xs);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.setting-item label i {
    color: var(--accent-primary);
    font-size: 0.8rem;
}

.setting-item input[type="text"] {
    padding: var(--space-sm) var(--space-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: all var(--transition-normal);
    font-family: inherit;
}

.setting-item input[type="text"]:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* Device selector */
.device-selector {
    display: flex;
    justify-content: center;
    margin-bottom: var(--space-xl);
    gap: var(--space-md);
    flex-wrap: wrap;
}

.device-button {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-lg);
    border: 2px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: var(--radius-xl);
    cursor: pointer;
    font-weight: 500;
    font-size: 0.875rem;
    transition: all var(--transition-normal);
    font-family: inherit;
}

.device-button:hover {
    border-color: var(--accent-primary);
    color: var(--text-primary);
    background: var(--bg-tertiary);
    transform: translateY(-1px);
}

.device-button.active {
    background: var(--gradient-primary);
    border-color: var(--accent-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.device-button i {
    font-size: 1rem;
}

/* Preview wrapper */
.preview-wrapper {
    position: relative;
    margin-bottom: var(--space-xl);
}

.preview-frame {
    display: none;
    animation: fadeIn var(--transition-normal);
}

.preview-frame.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* YouTube layout */
.youtube-layout {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--space-lg);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
    cursor: pointer;
}

.youtube-layout:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-hover);
}

.youtube-layout.desktop {
    max-width: 700px;
    margin: 0 auto;
    padding: var(--space-2xl);
    box-shadow: 0 8px 40px rgba(0,0,0,0.35);
}

.youtube-layout.tablet {
    max-width: 500px;
    margin: 0 auto;
    padding: var(--space-xl);
    box-shadow: 0 6px 30px rgba(0,0,0,0.30);
}

.youtube-layout.mobile {
    max-width: 340px;
    margin: 0 auto;
    padding: var(--space-lg);
    box-shadow: 0 4px 20px rgba(0,0,0,0.25);
}

/* Thumbnail container */
.thumbnail-container {
    position: relative;
    border-radius: var(--radius-xl);
    overflow: hidden;
    margin-bottom: var(--space-lg);
    background: var(--bg-tertiary);
    box-shadow: 0 4px 24px rgba(0,0,0,0.25);
    aspect-ratio: 16/9;
    width: 100%;
    height: auto;
    min-width: 0;
}

.thumbnail-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform var(--transition-normal);
    border-radius: 0;
    min-height: unset;
    max-height: unset;
}

.youtube-layout:hover .thumbnail-container img {
    transform: scale(1.02);
}

.video-duration {
    position: absolute;
    bottom: var(--space-xs);
    right: var(--space-xs);
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 2px var(--space-xs);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 500;
    font-family: 'JetBrains Mono', monospace;
}

/* Video info */
.video-info {
    padding: 0 var(--space-xs);
}

.video-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.channel-name {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    margin-bottom: var(--space-xs);
}

.channel-avatar {
    width: 24px;
    height: 24px;
    background: var(--gradient-accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    color: white;
}

.channel-name span {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.video-stats {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    line-height: 1.3;
}

/* Actions */
.actions {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.action-button {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-md) var(--space-xl);
    border: none;
    border-radius: var(--radius-xl);
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    font-family: inherit;
    text-decoration: none;
    min-width: 140px;
    justify-content: center;
}

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

.action-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    background: var(--gradient-secondary);
}

.action-button.secondary {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border: 2px solid var(--border-color);
}

.action-button.secondary:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border-color: var(--accent-primary);
}

.action-button i {
    font-size: 1rem;
}

/* Loading overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    backdrop-filter: blur(4px);
}

.loading-overlay.visible {
    opacity: 1;
    visibility: visible;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--bg-secondary);
    border-top: 3px solid var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Toast notifications */
.toast {
    position: fixed;
    top: var(--space-xl);
    right: var(--space-xl);
    background: var(--bg-card);
    color: var(--text-primary);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    z-index: 1001;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    max-width: 300px;
    font-weight: 500;
}

.toast.visible {
    transform: translateX(0);
}

.toast.success {
    border-left: 4px solid var(--accent-success);
}

.toast.error {
    border-left: 4px solid var(--accent-danger);
}

/* Footer */
footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--space-xl) 0;
    margin-top: var(--space-2xl);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
    text-align: center;
}

.footer-links {
    margin-bottom: var(--space-lg);
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    margin: 0 var(--space-sm);
    font-weight: 500;
    transition: color var(--transition-normal);
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
}

.footer-links a i {
    font-size: 0.9rem;
}

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

.footer-content p {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    margin-bottom: var(--space-lg);
}

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

.social-links a {
    color: var(--text-secondary);
    font-size: 1.25rem;
    transition: all var(--transition-normal);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    background: var(--bg-tertiary);
}

.social-links a:hover {
    color: var(--accent-primary);
    background: var(--bg-elevated);
    transform: translateY(-2px);
}

/* Theme toggle */
.theme-toggle {
    position: fixed;
    top: var(--space-lg);
    right: var(--space-lg);
    width: 48px;
    height: 48px;
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.theme-toggle:hover {
    border-color: var(--accent-primary);
    transform: scale(1.1);
    box-shadow: var(--shadow-lg);
}

.theme-toggle i {
    color: var(--text-secondary);
    font-size: 1.1rem;
    transition: color var(--transition-normal);
}

.theme-toggle:hover i {
    color: var(--accent-primary);
}

/* Responsive design */
@media (max-width: 1000px) {
    .container {
        padding: var(--space-lg);
    }
    
    .youtube-layout.desktop {
        max-width: 95vw;
        padding: var(--space-xl);
    }
    
    .youtube-layout.tablet {
        max-width: 90vw;
        padding: var(--space-lg);
    }
}

@media (max-width: 768px) {
    .upload-container {
        padding: var(--space-xl);
    }
    
    .youtube-layout.desktop {
        max-width: 98vw;
        padding: var(--space-lg);
    }
    
    .youtube-layout.tablet {
        max-width: 98vw;
        padding: var(--space-md);
    }
    
    .youtube-layout.mobile {
        max-width: 98vw;
        padding: var(--space-sm);
    }
    
    .thumbnail-container img {
        min-height: 180px;
        max-height: 220px;
    }
    
    .actions {
        flex-direction: column;
        align-items: center;
    }
    
    .action-button {
        width: 100%;
        max-width: 300px;
    }
    
    .settings-grid {
        grid-template-columns: 1fr;
    }
    
    .theme-toggle {
        top: var(--space-md);
        right: var(--space-md);
        width: 44px;
        height: 44px;
    }
    
    .upload-content h3 {
        font-size: 1.25rem;
    }
    
    .file-requirements {
        flex-direction: column;
        gap: var(--space-xs);
    }
    
    .footer-links {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-sm);
        margin-bottom: var(--space-lg);
    }
    
    .footer-links a {
        justify-content: center;
        margin: 0;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.75rem;
    }
    
    .preview-container {
        padding: var(--space-lg);
    }
    
    .youtube-layout.desktop,
    .youtube-layout.tablet,
    .youtube-layout.mobile {
        max-width: 100vw;
        padding: var(--space-xs);
    }
    
    .thumbnail-container img {
        min-height: 120px;
        max-height: 160px;
    }
    
    .device-selector {
        flex-direction: column;
        align-items: center;
    }
    
    .device-button {
        width: 100%;
        max-width: 200px;
    }
    
    .upload-content h3 {
        font-size: 1.1rem;
    }
    
    .preview-container h2 {
        font-size: 1.5rem;
    }
    
    .preview-container h2 i {
        font-size: 1.4rem;
    }
}

/* Header styling */
.app-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.app-header h1 {
    margin-bottom: var(--space-md);
}

/* Upload content */
.upload-content {
    position: relative;
    z-index: 1;
}

.upload-content h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    letter-spacing: -0.01em;
}

.upload-content p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    position: relative;
    z-index: 1;
    font-weight: 500;
}

/* Loading overlay text */
.loading-overlay p {
    color: var(--text-primary);
    margin-top: var(--space-md);
    font-weight: 500;
    text-align: center;
}