@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;600&family=Poppins:wght@600&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Roboto+Slab:wght@700&display=swap');

/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: linear-gradient(135deg, #0A66C2, #6E5494);
    color: #FFFFFF;
    font-family: 'Open Sans', sans-serif;
    line-height: 1.6;
    padding: 20px;
}

/* 头部导航 */
header {
    width: 100%;
    padding: 20px 0;
    background: rgba(51, 51, 51, 0.8);
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
}

.navbar {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar a {
    color: #FFFFFF;
    text-decoration: none;
    margin-left: 20px;
    font-weight: 600;
    transition: color 0.3s ease;
}

.navbar a:hover {
    color: #FF6F61;
}

.main-content {
    max-width: 1200px;
    margin: 100px auto 50px auto;
    padding: 20px;
    background: rgba(51, 51, 51, 0.7);
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

/* 标题样式 */
h1, h2, h3, h4 {
    font-family: 'Roboto Slab', serif;
    color: #FFFFFF;
    margin-bottom: 15px;
}

h1 {
    font-size: 2.5em;
    text-align: center;
    margin-bottom: 30px;
}

h2 {
    font-size: 2em;
    margin-top: 30px;
    margin-bottom: 20px;
}

h3 {
    font-size: 1.75em;
    margin-top: 25px;
    margin-bottom: 15px;
}

h4 {
    font-size: 1.5em;
    margin-top: 20px;
    margin-bottom: 10px;
}

/* 段落与列表 */
p {
    font-family: 'Open Sans', sans-serif;
    color: #DDDDDD;
    margin-bottom: 20px;
}

ul {
    list-style-type: disc;
    margin-left: 20px;
    margin-bottom: 20px;
}

ul li {
    margin-bottom: 10px;
}

/* 卡片布局 */
.cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.card {
    background: linear-gradient(145deg, #333333, #444444);
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 20px rgba(0,0,0,0.5);
}

.card img {
    width: 100%;
    height: auto;
    border-radius: 5px;
    margin-bottom: 15px;
}

.card h4 {
    color: #FF6F61;
    margin-bottom: 10px;
}

.card p {
    color: #CCCCCC;
    font-size: 0.95em;
}

/* 示例展示 */
.example-section {
    margin-top: 50px;
    padding: 20px;
    background: rgba(110, 84, 148, 0.8);
    border-radius: 10px;
}

.example-section h2::after {
    content: '（示例展示）';
    font-weight: normal;
    font-size: 0.8em;
    color: #76C893;
    margin-left: 10px;
}

.example-section article {
    background: #222222;
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
    overflow-x: auto;
}

.example-section pre {
    background: #1e1e1e;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
}

.example-section code {
    font-family: 'Courier New', Courier, monospace;
    color: #76C893;
}

/* 提示语 */
.footer {
    text-align: center;
    padding: 20px;
    color: #FFFFFF;
    margin-top: 50px;
    font-size: 1.2em;
}

/* 响应式设计 */
@media (max-width: 1440px) {
    .main-content {
        max-width: 1100px;
    }
}

@media (max-width: 1200px) {
    .main-content {
        max-width: 1000px;
    }
}

@media (max-width: 1024px) {
    .navbar a {
        margin-left: 15px;
    }
    .cards-container {
        grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    }
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        align-items: flex-start;
    }
    .navbar a {
        margin-left: 0;
        margin-top: 10px;
    }
    .cards-container {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 2em;
    }
    h2 {
        font-size: 1.75em;
    }
    h3 {
        font-size: 1.5em;
    }
    .cards-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 320px) {
    body {
        padding: 10px;
    }
    .navbar {
        flex-direction: column;
        align-items: flex-start;
    }
    .navbar a {
        margin-left: 0;
        margin-top: 10px;
    }
    .main-content {
        margin: 80px auto 20px auto;
        padding: 15px;
    }
    .cards-container {
        grid-template-columns: 1fr;
    }
}