:root {
    --bg-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --bg-container: rgba(255, 255, 255, 0.95);
    --bg-header: linear-gradient(45deg, #ff6b6b, #ee5a24);
    --text-header: white;
    --text-primary: #2d3436;
    --text-secondary: #495057;
    --text-accent: #d63031;
    --text-link: #1976d2;
    --border-color: #ddd;
    --border-focus-color: #667eea;
    --input-bg: #f8f9fa;
    --input-bg-focus: white;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --shadow-focus-color: rgba(102, 126, 234, 0.1);
    --btn-primary-bg: linear-gradient(45deg, #667eea, #764ba2);
    --btn-primary-text: white;
    --btn-secondary-bg: #f8f9fa;
    --btn-secondary-text: #495057;
    --btn-secondary-border: #dee2e6;
    --btn-download-bg: linear-gradient(45deg, #00b894, #00cec9);
    --btn-download-text: white;
    --notice-bg: #fff3cd;
    --notice-border: #ffeaa7;
    --ss-trick-bg: #e3f2fd;
    --ss-trick-border: #90caf9;
    --format-item-bg: #f8f9fa;
    --format-item-border: #e9ecef;
    --format-item-hover-bg: #e3f2fd;
    --format-item-hover-border: #90caf9;
    --error-bg: #ffe6e6;
    --error-border: #ff9999;
    --error-text: #d63031;
    --progress-bar-bg: #e9ecef;
    --slider-bg: #ccc;
    --slider-checked-bg: #667eea;
    --success-bg: #d4edda;
    --success-border: #c3e6cb;
    --success-text: #155724;
}

body.dark-mode {
    --bg-primary: linear-gradient(135deg, #232526 0%, #414345 100%);
    --bg-container: rgba(45, 52, 54, 0.9);
    --bg-header: linear-gradient(45deg, #d35400, #c0392b);
    --text-header: #f1f2f6;
    --text-primary: #f1f2f6;
    --text-secondary: #bdc3c7;
    --text-accent: #e74c3c;
    --text-link: #3498db;
    --border-color: #555;
    --border-focus-color: #3498db;
    --input-bg: #3b3f42;
    --input-bg-focus: #4a4e52;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-focus-color: rgba(52, 152, 219, 0.2);
    --btn-primary-bg: linear-gradient(45deg, #3498db, #2980b9);
    --btn-primary-text: white;
    --btn-secondary-bg: #4a4e52;
    --btn-secondary-text: #f1f2f6;
    --btn-secondary-border: #5f6769;
    --btn-download-bg: linear-gradient(45deg, #16a085, #1abc9c);
    --btn-download-text: white;
    --notice-bg: #2c3e50;
    --notice-border: #34495e;
    --ss-trick-bg: #34495e;
    --ss-trick-border: #2c3e50;
    --format-item-bg: #3b3f42;
    --format-item-border: #4a4e52;
    --format-item-hover-bg: #4a4e52;
    --format-item-hover-border: #529ECC;
    --error-bg: #5e2929;
    --error-border: #c0392b;
    --error-text: #f1f2f6;
    --progress-bar-bg: #4a4e52;
    --slider-bg: #555;
    --slider-checked-bg: #3498db;
    --success-bg: #1b4d3e;
    --success-border: #27ae60;
    --success-text: #a9dfbf;
}

/* URL Detection Success Message */
.url-detected {
    background-color: var(--success-bg);
    border: 1px solid var(--success-border);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 20px;
    animation: slideDown 0.5s ease-out;
}

.url-detected h3 {
    color: var(--success-text);
    margin-bottom: 10px;
    font-size: 1.2rem;
}

.url-detected p {
    color: var(--success-text);
    line-height: 1.6;
    margin: 0;
}

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

/* Theme Switch Styles */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
    gap: 10px;
    position: absolute;
    top: 20px;
    right: 20px;
}

.theme-switch-label {
    color: var(--text-header);
    font-size: 0.9rem;
}

.theme-switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 28px;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--slider-bg);
    transition: .4s;
    border-radius: 28px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 20px;
    width: 20px;
    left: 4px;
    bottom: 4px;
    background-color: var(--input-bg-focus);
    transition: .4s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--slider-checked-bg);
}

input:focus + .slider {
    box-shadow: 0 0 1px var(--slider-checked-bg);
}

input:checked + .slider:before {
    transform: translateX(22px);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-primary);
    min-height: 100vh;
    padding: 20px;
    transition: background 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background-color: var(--bg-container);
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow-color);
    overflow: hidden;
    backdrop-filter: blur(10px);
}

.header {
    background: var(--bg-header);
    color: var(--text-header);
    padding: 30px;
    text-align: center;
    position: relative;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.header p {
    opacity: 0.9;
    font-size: 1.1rem;
}

.content {
    padding: 40px;
}

.legal-notice {
    background-color: var(--notice-bg);
    border: 1px solid var(--notice-border);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 30px;
}

.legal-notice h3 {
    color: var(--text-accent);
    margin-bottom: 10px;
}

.legal-notice p {
    color: var(--text-primary);
    line-height: 1.6;
}

.input-section {
    margin-bottom: 30px;
}

.input-group {
    position: relative;
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-secondary);
}

.url-input {
    width: 100%;
    padding: 15px 20px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 16px;
    color: var(--text-primary);
    background-color: var(--input-bg);
    transition: all 0.3s ease;
}

.url-input:focus {
    outline: none;
    border-color: var(--border-focus-color);
    background-color: var(--input-bg-focus);
    box-shadow: 0 0 0 3px var(--shadow-focus-color);
}

.ss-trick {
    background-color: var(--ss-trick-bg);
    border: 1px solid var(--ss-trick-border);
    border-radius: 10px;
    padding: 15px;
    margin-top: 15px;
}

.ss-trick h4 {
    color: var(--text-link);
    margin-bottom: 8px;
}

.ss-trick p {
    color: var(--text-secondary);
    font-size: 14px;
}

.buttons {
    margin-top: 10px;
    gap: 15px;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: var(--btn-primary-bg);
    color: var(--btn-primary-text);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px var(--shadow-color);
}

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

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

.loading {
    display: none;
    text-align: center;
    padding: 30px;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--border-focus-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

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

.video-info {
    display: none;
    background-color: var(--bg-container);
    border-radius: 12px;
    padding: 25px;
    margin-top: 30px;
    box-shadow: 0 5px 15px var(--shadow-color);
    border: 1px solid var(--border-color);
}

.video-thumbnail {
    width: 100%;
    max-width: 300px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.video-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 15px;
    line-height: 1.4;
}

.video-details {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.formats-section {
    margin-top: 25px;
}

.format-category {
    margin-bottom: 25px;
}

.format-category h4 {
    color: var(--text-primary);
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.format-list {
    display: grid;
    gap: 10px;
}

.format-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background-color: var(--format-item-bg);
    border: 1px solid var(--format-item-border);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.format-item:hover {
    background-color: var(--format-item-hover-bg);
    border-color: var(--format-item-hover-border);
}

.format-info {
    flex: 1;
}

.format-quality {
    font-weight: 600;
    color: var(--text-primary);
}

.format-details {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 4px;
}

.download-btn {
    background: var(--btn-download-bg);
    color: var(--btn-download-text);
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.download-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 5px 10px var(--shadow-color);
}

.error {
    background-color: var(--error-bg);
    border: 1px solid var(--error-border);
    color: var(--error-text);
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    display: none;
}

.progress {
    display: none;
    margin-top: 20px;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background-color: var(--progress-bar-bg);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--btn-download-bg);
    width: 0%;
    transition: width 0.3s ease;
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 2rem;
    }
    
    .content {
        padding: 30px 20px;
    }
    
    .buttons {
        flex-direction: column;
    }
    
    .btn {
        justify-content: center;
    }
    
    .theme-switch-wrapper {
        position: static;
        justify-content: center;
        margin-top: 15px;
    }
}