* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: rgba(30, 41, 59, 0.6);
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --border-color: rgba(148, 163, 184, 0.2);
    --success: #10b981;
    --error: #ef4444;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    padding: 2rem 1rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInDown 0.6s ease-out;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Input Section */
.input-section {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
    animation: fadeInUp 0.6s ease-out 0.1s both;
}

.input-group {
    display: flex;
    gap: 1rem;
    margin-bottom: 0.75rem;
}

#youtube-url {
    flex: 1;
    padding: 1rem 1.5rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
}

#youtube-url:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

#youtube-url::placeholder {
    color: var(--text-muted);
}

.btn-primary, .btn-secondary {
    padding: 1rem 2rem;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: inherit;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    min-width: 140px;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-primary.loading .btn-text {
    opacity: 0;
}

.btn-primary.loading .btn-loader {
    opacity: 1;
}

.btn-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    opacity: 0;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-secondary:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.hint {
    color: var(--text-muted);
    font-size: 0.875rem;
    text-align: center;
}

/* Error Message */
.error-message {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error);
    border-radius: 12px;
    padding: 1rem 1.5rem;
    margin-bottom: 2rem;
    color: #fca5a5;
    animation: shake 0.4s ease-out;
}

.hidden {
    display: none !important;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

/* Results */
.results {
    animation: fadeInUp 0.6s ease-out;
}

.thumbnail-section {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 2rem;
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

#thumbnail {
    width: 100%;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
}

.basic-info h2 {
    font-size: 1.75rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.channel-info, .stats {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.separator {
    color: var(--text-muted);
}

.stats {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Metadata Grid */
.metadata-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.metadata-card {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

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

.metadata-card label {
    display: block;
    color: var(--text-muted);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.metadata-value {
    color: var(--text-primary);
    font-size: 1rem;
    word-break: break-all;
}

.metadata-value a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

.metadata-value a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}

/* Section Card */
.section-card {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

.section-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.description-content {
    color: var(--text-secondary);
    line-height: 1.8;
    white-space: pre-wrap;
    max-height: 300px;
    overflow-y: auto;
    padding-right: 1rem;
}

/* Keywords */
.keywords-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.keyword-tag {
    background: rgba(99, 102, 241, 0.1);
    color: var(--accent-primary);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.875rem;
    border: 1px solid rgba(99, 102, 241, 0.2);
    transition: all 0.2s ease;
}

.keyword-tag:hover {
    background: rgba(99, 102, 241, 0.2);
    transform: translateY(-2px);
}

/* Transcript */
.transcript-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    color: var(--text-secondary);
    line-height: 1.8;
    white-space: pre-wrap;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
    font-size: 0.9rem;
    max-height: 500px;
    overflow-y: auto;
}

/* Custom Scrollbar */
.description-content::-webkit-scrollbar,
.transcript-content::-webkit-scrollbar {
    width: 8px;
}

.description-content::-webkit-scrollbar-track,
.transcript-content::-webkit-scrollbar-track {
    background: var(--bg-primary);
    border-radius: 4px;
}

.description-content::-webkit-scrollbar-thumb,
.transcript-content::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 4px;
}

.description-content::-webkit-scrollbar-thumb:hover,
.transcript-content::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}

/* Footer */
.footer {
    text-align: center;
    margin-top: 4rem;
    padding: 2rem;
    color: var(--text-muted);
}

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

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 768px) {
    .thumbnail-section {
        grid-template-columns: 1fr;
    }
    
    .input-group {
        flex-direction: column;
    }
    
    .metadata-grid {
        grid-template-columns: 1fr;
    }
    
    .logo h1 {
        font-size: 2rem;
    }
}