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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f5f5f5;
    min-height: 100vh;
    padding: 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark-mode {
    background: #1a1a1a;
    color: #e0e0e0;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    padding: 20px 0;
    position: relative;
    transition: color 0.3s ease;
}

body.dark-mode header {
    color: #e0e0e0;
}

header h1 {
    font-size: 2rem;
    margin-bottom: 8px;
    color: #2c3e50;
    transition: color 0.3s ease;
}

body.dark-mode header h1 {
    color: #ecf0f1;
}

header p {
    font-size: 1rem;
    color: #666;
    transition: color 0.3s ease;
}

body.dark-mode header p {
    color: #b0b0b0;
}

.theme-toggle {
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    background: #fff;
    border: 2px solid #e0e0e0;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.theme-toggle:hover {
    transform: translateY(-50%) scale(1.1);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
    border-color: #3498db;
}

body.dark-mode .theme-toggle {
    background: #2c2c2c;
    border-color: #444;
}

body.dark-mode .theme-toggle:hover {
    border-color: #f39c12;
}

.theme-tooltip {
    position: absolute;
    bottom: -35px;
    left: 50%;
    transform: translateX(-50%) translateY(-10px);
    background: rgba(0, 0, 0, 0.85);
    color: #fff;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    pointer-events: none;
    z-index: 1000;
}

.theme-tooltip::before {
    content: '';
    position: absolute;
    top: -6px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 6px solid transparent;
    border-right: 6px solid transparent;
    border-bottom: 6px solid rgba(0, 0, 0, 0.85);
}

.theme-tooltip.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.theme-toggle:hover .theme-tooltip {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.section {
    margin-bottom: 30px;
}

.section-title {
    color: #2c3e50;
    font-size: 1.4rem;
    margin-bottom: 15px;
    padding: 10px 15px;
    border-left: 4px solid #3498db;
    background: #fff;
    border-radius: 4px;
    transition: all 0.3s ease;
}

body.dark-mode .section-title {
    color: #ecf0f1;
    background: #2c2c2c;
    border-left-color: #f39c12;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
}

.card {
    background: white;
    border-radius: 8px;
    padding: 18px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    border: 1px solid #e0e0e0;
}

body.dark-mode .card {
    background: #2c2c2c;
    border-color: #444;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, #3498db, #2980b9);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

body.dark-mode .card::before {
    background: linear-gradient(90deg, #f39c12, #e67e22);
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
    border-color: #3498db;
}

body.dark-mode .card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    border-color: #f39c12;
}

.card:hover::before {
    transform: scaleX(1);
}

.card-header {
    margin-bottom: 12px;
}

.card-title {
    font-size: 1.1rem;
    color: #2c3e50;
    margin-bottom: 6px;
    font-weight: 600;
    transition: color 0.3s ease;
}

body.dark-mode .card-title {
    color: #ecf0f1;
}

.card-link {
    display: inline-block;
    color: #3498db;
    text-decoration: none;
    font-size: 0.85rem;
    word-break: break-all;
    transition: color 0.2s ease;
}

body.dark-mode .card-link {
    color: #f39c12;
}

.card-link:hover {
    color: #2980b9;
    text-decoration: underline;
}

body.dark-mode .card-link:hover {
    color: #e67e22;
}

.card-description {
    color: #666;
    line-height: 1.5;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

body.dark-mode .card-description {
    color: #b0b0b0;
}

.empty-state {
    text-align: center;
    color: #999;
    padding: 30px;
    background: #fff;
    border-radius: 8px;
    border: 1px dashed #ddd;
    transition: all 0.3s ease;
}

body.dark-mode .empty-state {
    background: #2c2c2c;
    border-color: #444;
    color: #888;
}

.empty-state p {
    font-size: 0.95rem;
}

footer {
    text-align: center;
    color: #999;
    margin-top: 40px;
    padding: 25px 20px;
    font-size: 0.9rem;
    background: #fff;
    border-top: 1px solid #e0e0e0;
    transition: all 0.3s ease;
}

body.dark-mode footer {
    background: #2c2c2c;
    border-top-color: #444;
    color: #888;
}

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

.copyright {
    margin-bottom: 10px;
    color: #666;
    transition: color 0.3s ease;
}

body.dark-mode .copyright {
    color: #b0b0b0;
}

.beian-info {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    font-size: 0.85rem;
}

.beian-link {
    color: #999;
    text-decoration: none;
    transition: color 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

body.dark-mode .beian-link {
    color: #888;
}

.beian-link:hover {
    color: #3498db;
}

body.dark-mode .beian-link:hover {
    color: #f39c12;
}

.beian-divider {
    color: #ddd;
    user-select: none;
    transition: color 0.3s ease;
}

body.dark-mode .beian-divider {
    color: #555;
}

.beian-icon {
    vertical-align: middle;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 1.6rem;
    }

    .section-title {
        font-size: 1.2rem;
    }

    .cards-grid {
        grid-template-columns: 1fr;
    }

    .card {
        padding: 15px;
    }

    .theme-toggle {
        width: 40px;
        height: 40px;
        font-size: 1.1rem;
        right: 10px;
    }

    .theme-tooltip {
        font-size: 0.75rem;
        padding: 5px 10px;
        bottom: -32px;
    }

    footer {
        padding: 20px 15px;
        font-size: 0.85rem;
    }

    .beian-info {
        flex-direction: column;
        gap: 8px;
    }

    .beian-divider {
        display: none;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }

    header h1 {
        font-size: 1.4rem;
    }

    header p {
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.1rem;
        padding: 8px 12px;
    }

    .card-title {
        font-size: 1rem;
    }
    
    footer {
        padding: 15px 10px;
        font-size: 0.8rem;
    }
}