/* 全局样式 */
body {
    margin: 0;
    padding: 0;
    font-family: 'Arial', sans-serif;
    background-color: #f0f0f0; /* 科技灰背景 */
    color: #333;
    line-height: 1.6;
}

/* 容器样式 */
.container {
    max-width: 1200px;
    margin: 50px auto;
    padding: 20px;
}

/* 标题样式 */
h1 {
    font-size: 42px;
    color: #0073e6; /* 化工蓝 */
    text-align: center;
    margin-bottom: 40px;
    font-weight: bold;
}

h2 {
    font-size: 24px;
    color: #0073e6; /* 化工蓝 */
    margin-bottom: 15px;
    font-weight: bold;
}

/* 卡片样式 */
.card {
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

.card-header {
    background-color: #0073e6; /* 化工蓝 */
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.card-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: #fff;
    padding: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.card-header h2 {
    color: #fff;
    margin: 0;
}

.card-body {
    padding: 20px;
}

/* 三列列表样式 */
.three-column {
    list-style-type: none;
    padding: 0;
    margin: 0;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    justify-content: space-between; /* 两端对齐 */
}

.three-column li {
    margin-bottom: 10px;
    font-size: 16px;
    text-align: center; /* 文字居中 */
}

.three-column li a {
    color: #0073e6; /* 化工蓝 */
    text-decoration: none;
    transition: color 0.3s ease;
}

.three-column li a:hover {
    color: #005bb5; /* 深化工蓝 */
}

/* 响应式布局 */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    h1 {
        font-size: 36px;
    }

    h2 {
        font-size: 20px;
    }

    .card-header {
        padding: 15px;
    }

    .card-body {
        padding: 15px;
    }

    .card-icon {
        width: 30px;
        height: 30px;
        padding: 8px;
    }

    .three-column {
        grid-template-columns: repeat(2, 1fr); /* 移动端改为两列 */
    }
}

@media (max-width: 480px) {
    .three-column {
        grid-template-columns: 1fr; /* 小屏幕改为单列 */
    }
}