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

:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --dark-gradient: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
    --card-bg: rgba(255, 255, 255, 0.95);
    --text-primary: #2d3748;
    --text-secondary: #718096;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 20px 60px rgba(0, 0, 0, 0.15);
    --border-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
    z-index: -1;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInDown 0.8s ease-out;
}

.title {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, #ffffff 0%, #f0f0f0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
    text-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.subtitle {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 400;
}

.main-content {
    flex: 1;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-decoration: none;
    color: var(--text-primary);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow);
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
    animation-fill-mode: both;
}

.card:nth-child(1) {
    animation-delay: 0.1s;
}

.card:nth-child(2) {
    animation-delay: 0.2s;
}

.card:nth-child(3) {
    animation-delay: 0.3s;
}

.card:nth-child(4) {
    animation-delay: 0.4s;
}

.card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-hover);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: var(--transition);
}

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

.card-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    font-size: 2rem;
    transition: var(--transition);
    position: relative;
    z-index: 1;
}

.card:nth-child(1) .card-icon {
    background: var(--primary-gradient);
    color: white;
}

.card:nth-child(2) .card-icon {
    background: var(--secondary-gradient);
    color: white;
}

.card:nth-child(3) .card-icon {
    background: var(--accent-gradient);
    color: white;
}

.card:nth-child(4) .card-icon {
    background: var(--dark-gradient);
    color: white;
}

.card:hover .card-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
    transition: var(--transition);
}

.card:hover .card-title {
    color: #667eea;
}

.card-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    transition: var(--transition);
    margin-bottom: 1.5rem;
}

.card:hover .card-description {
    color: var(--text-primary);
}

.card-hover-effect {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(102, 126, 234, 0.1);
    transform: translate(-50%, -50%);
    transition: var(--transition);
    z-index: 0;
}

.card:hover .card-hover-effect {
    width: 300px;
    height: 300px;
}

.footer {
    text-align: center;
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
    margin-top: 2rem;
    animation: fadeIn 1s ease-out 0.5s both;
}

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

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

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1.5rem;
    }
    
    .title {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .card {
        padding: 1.5rem;
    }
    
    .card-title {
        font-size: 1.25rem;
    }
    
    .card-icon {
        width: 60px;
        height: 60px;
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .title {
        font-size: 1.75rem;
    }
    
    .card {
        padding: 1.25rem;
    }
    
    .card-title {
        font-size: 1.125rem;
    }
    
    .card-description {
        font-size: 0.875rem;
    }
}

/* 添加滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5);
}