/* 全局样式设置 */
/* 定义颜色变量，主色70%，辅色25%，点缀色5% */
:root {
    --main-color: #0d47a1; /* 主色调：深蓝色，传达专业与科技感 */
    --secondary-color: #b0bec5; /* 辅色调：银灰色，增强层次感 */
    --accent-color: #ffeb3b; /* 点缀色：亮黄色，吸引视觉焦点 */
}

/* 设置全局字体与背景 */
body {
    margin: 0;
    padding: 0;
    font-family: 'Helvetica Neue', sans-serif;
    background: linear-gradient(135deg, var(--main-color) 70%, var(--secondary-color) 25%, #ffffff 5%);
    color: #ffffff;
    overflow-x: hidden;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(13, 71, 161, 0.9);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 1000;
}

.navbar a {
    color: #ffffff;
    text-decoration: none;
    margin: 0 15px;
    font-weight: bold;
    transition: color 0.3s ease;
}

.navbar a:hover {
    color: var(--accent-color);
}

/* 面包屑导航样式 */
.breadcrumb {
    display: flex;
    list-style: none;
    padding: 10px 20px;
    background: rgba(176, 190, 197, 0.8);
    border-radius: 5px;
    margin: 80px 20px 20px 20px;
}

.breadcrumb li + li:before {
    content: '>';
    padding: 0 8px;
    color: var(--accent-color);
}

/* 主内容容器 */
.container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    padding: 40px;
}

/* 卡片样式 */
.card {
    background: rgba(255, 255, 255, 0.1);
    color: #000;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    padding: 20px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.2);
}

/* 装饰性图片样式 */
img.decorative-image {
    max-width: 650px;
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

img.decorative-image:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 16px rgba(0,0,0,0.3);
}

/* 标题样式 */
h2, h3, h4 {
    font-family: 'Roboto', sans-serif;
    color: var(--accent-color);
    margin-bottom: 20px;
}

h2 {
    font-size: 24px;
}

h3 {
    font-size: 20px;
}

p {
    font-size: 16px;
    line-height: 1.6;
    color: #fff;
}

/* 代码块样式 */
pre code.language-css {
    background: rgba(255, 255, 255, 0.1);
    padding: 15px;
    border-radius: 8px;
    display: block;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
    color: #ffeb3b;
}

/* 鼠标悬停效果 */
a:hover, .button:hover {
    color: var(--accent-color);
}

/* 响应式设计 */
@media (max-width: 500px) {
    .container {
        grid-template-columns: 1fr;
    }
}

/* 折叠区域样式 */
.collapsible {
    background-color: var(--secondary-color);
    color: #000;
    cursor: pointer;
    padding: 18px;
    width: 100%;
    border: none;
    text-align: left;
    outline: none;
    font-size: 16px;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.collapsible:hover {
    background-color: var(--main-color);
    color: var(--accent-color);
}

.content {
    padding: 0 18px;
    display: none;
    background-color: rgba(255,255,255,0.1);
    overflow: hidden;
    border-radius: 5px;
}

/* 按钮样式 */
.button {
    background-color: var(--accent-color);
    border: none;
    color: #000;
    padding: 10px 20px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.button:hover {
    background-color: #fff176;
}

/* 表格样式 */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

th, td {
    padding: 15px;
    text-align: left;
    color: #fff;
}

thead {
    background: var(--main-color);
}

tbody tr:nth-child(even) {
    background: rgba(176, 190, 197, 0.2);
}

tbody tr:hover {
    background: rgba(255, 235, 59, 0.3);
}

th {
    font-weight: bold;
}