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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
    padding: 20px;
    position: relative;
}

/* 左上角标题样式 */
.corner-title {
    position: absolute;
    top: 20px;
    left: 20px;
    font-size: 2.2rem;
    color: #2c3e50;
    font-weight: 700;
    letter-spacing: 1px;
    padding: 10px 20px;
    background: rgba(255, 255, 255, 0.8);
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    z-index: 10;
}

/* 主内容区域 */
.main-content {
    max-width: 1400px;
    margin: 80px auto 30px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
}

.card {
    background: white;
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
    padding: 30px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.12);
}

.card:hover::after {
    opacity: 1;
}

.card-title {
    font-size: 1.6rem;
    color: #2c3e50;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
    position: relative;
    z-index: 2;
}

.card-content {
    font-size: 1.1rem;
    color: #555;
    line-height: 1.7;
    position: relative;
    z-index: 2;
}

.full-width {
    grid-column: 1 / -1;
}

.divider {
    height: 2px;
    background: #3498db;
    margin: 25px 0;
    border-radius: 2px;
}

/* 特性网格 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 20px;
}

.feature {
    text-align: center;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #2c3e50;
}

.feature:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.12);
}

.feature:hover::after {
    opacity: 1;
}


/* 链接指示器 */
.link-indicator {
    position: absolute;
    top: 15px;
    right: 15px;
    color: #3498db;
    font-size: 1.2rem;
    opacity: 0.7;
    transition: opacity 0.3s ease;
    z-index: 2;
}

.card:hover .link-indicator {
    opacity: 1;
}

.feature:hover .link-indicator {
    opacity: 1;
}

/* 装饰元素 */
.decorative-circle {
    position: fixed;
    width: 250px;
    height: 250px;
    border-radius: 50%;
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.1) 0%, rgba(46, 204, 113, 0.1) 100%);
    bottom: 30px;
    right: 30px;
    z-index: -1;
}

/* 响应式设计 */
@media (max-width: 1200px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 900px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 600px) {
    .corner-title {
        font-size: 1.8rem;
        top: 15px;
        left: 15px;
        padding: 8px 15px;
    }
    
    .main-content {
        margin-top: 70px;
    }
    
    .card {
        padding: 20px;
    }
    
    .card-title {
        font-size: 1.4rem;
    }
    
    .decorative-circle {
        width: 150px;
        height: 150px;
        bottom: 20px;
        right: 20px;
    }
}