/* 
整体页面样式设计
主色调为深蓝色，辅色为电蓝色，点缀色为白色
使用了CSS3的高级特性，如渐变、阴影、动画、过渡等
确保页面在不同设备上的响应式布局，适应320px到1920px宽度范围
*/

body {
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #121E3B 70%, #00BFFF 25%, #FFFFFF 5%);
    font-family: 'Roboto', sans-serif;
    color: #FFFFFF;
    overflow-x: hidden; /* 避免出现左右滚动条 */
}

/* 导航栏样式 */
.navigation {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(18, 30, 59, 0.9);
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding: 15px 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.navigation a {
    color: #00BFFF;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s;
}

.navigation a:hover {
    color: #FFFFFF;
}

/* 头部展示区 */
.header {
    height: 100vh;
    background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 20px;
}

.header h1 {
    font-size: 48px;
    margin-bottom: 20px;
    animation: fadeInDown 2s ease-out both;
}

.header p {
    font-size: 18px;
    max-width: 800px;
    animation: fadeInUp 2s ease-out both;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 功能展示区 */
.function-section {
    padding: 80px 20px;
    background-color: rgba(18, 30, 59, 0.8);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    align-items: center;
}

.function-item {
    width: 300px;
    margin: 20px;
    background-color: rgba(0, 191, 255, 0.2);
    border-radius: 10px;
    padding: 30px 20px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    transition: transform 0.3s, box-shadow 0.3s;
}

.function-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 15px rgba(0,0,0,0.4);
}

.function-item img {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    transition: transform 0.3s;
}

.function-item img:hover {
    transform: scale(1.1);
}

.function-item h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

.function-item p {
    font-size: 16px;
    line-height: 1.5;
}

/* 用户案例区 */
.case-section {
    padding: 80px 20px;
    background-color: rgba(0, 100, 0, 0.8);
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.case-item {
    background-color: rgba(34, 139, 34, 0.8);
    padding: 20px;
    border-radius: 8px;
    transition: background-color 0.3s;
}

.case-item:hover {
    background-color: #2E8B57;
}

.case-item img {
    width: 100%;
    height: auto;
    border-radius: 5px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.case-item h4 {
    font-size: 18px;
    margin: 15px 0 10px 0;
}

.case-item p {
    font-size: 14px;
    line-height: 1.4;
}

/* 实时数据展示区 */
.data-section {
    padding: 80px 20px;
    background-color: rgba(18, 30, 59, 0.9);
    display: flex;
    justify-content: space-around;
    align-items: center;
    flex-wrap: wrap;
}

.data-item {
    flex: 1 1 200px;
    margin: 20px;
    text-align: center;
}

.data-item span {
    display: block;
    font-size: 2.5em;
    color: #00BFFF;
    animation: countUp 2s ease-out forwards;
}

@keyframes countUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.data-item p {
    font-size: 16px;
    margin-top: 10px;
}

/* 动态光效与交互动效 */
.chart {
    width: 100%;
    height: 300px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    animation: loadChart 1s ease-out forwards;
}

@keyframes loadChart {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 按钮样式 */
.button {
    background-color: #00BFFF;
    color: #FFFFFF;
    padding: 12px 25px;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    font-size: 16px;
    transition: transform 0.3s, background-color 0.3s;
}

.button:hover {
    transform: scale(1.1);
    background-color: #1E90FF;
}

/* 折叠区域样式 */
.collapsible {
    background-color: rgba(18, 30, 59, 0.7);
    color: #FFFFFF;
    cursor: pointer;
    padding: 15px;
    width: 100%;
    border: none;
    text-align: left;
    outline: none;
    font-size: 18px;
    transition: background-color 0.3s;
}

.collapsible:hover {
    background-color: rgba(0, 191, 255, 0.5);
}

.content {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background-color: rgba(0, 191, 255, 0.1);
}

.active + .content {
    max-height: 500px; /* 根据内容调整 */
}

/* 章节导航系统 */
.chapter-nav {
    position: fixed;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(18, 30, 59, 0.8);
    padding: 10px;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
}

.chapter-nav a {
    color: #00BFFF;
    text-decoration: none;
    margin: 5px 0;
    font-size: 14px;
    transition: color 0.3s;
}

.chapter-nav a:hover {
    color: #FFFFFF;
}

/* CSS代码示例区 */
.code-example {
    background-color: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 20px 0;
}

.code-example code {
    font-family: 'Courier New', Courier, monospace;
    color: #00BFFF;
}

/* 图片样式 */
img.decorative {
    width: 320px;
    height: 320px;
    border-radius: 15px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    transition: transform 0.3s, box-shadow 0.3s;
    margin: 10px;
}

img.decorative:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 16px rgba(0,0,0,0.5);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navigation {
        flex-direction: column;
    }
    .function-section, .data-section {
        flex-direction: column;
    }
    .chapter-nav {
        display: none;
    }
}