/* 全局样式与布局基础 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica', 'Roboto', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #f5f5f5;
    background: linear-gradient(to bottom, #000066, #000000);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: bold;
    color: #ffffff;
}

p {
    font-size: 1rem;
    margin-bottom: 1rem;
}

ul {
    list-style: none;
    padding-left: 1.5rem;
}

a {
    color: #00ff99;
    text-decoration: none;
    transition: color 0.3s ease-in-out;
}

a:hover {
    color: #00cc77;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* 顶部导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: linear-gradient(to right, #000066, #000033);
    z-index: 1000;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
}

.navbar .logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #00ff99;
}

.navbar .menu {
    display: flex;
    gap: 20px;
}

.navbar .menu a {
    font-size: 1rem;
    padding: 5px 10px;
    border-radius: 4px;
}

.navbar .menu a:hover {
    background: #00ff99;
    color: #000033;
}

/* 首页大背景与标语 */
.hero {
    height: 100vh;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center center/cover,
                linear-gradient(to bottom, #000066, #000000);
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: #ffffff;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1;
}

.hero h1 {
    font-size: 3rem;
    z-index: 2;
    position: relative;
    animation: fadeIn 2s ease-in-out;
}

.hero p {
    font-size: 1.5rem;
    z-index: 2;
    position: relative;
    animation: fadeIn 2.5s ease-in-out;
}

/* 功能模块卡片 */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.feature-item {
    background: linear-gradient(to bottom, #000033, #00001a);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease-in-out;
}

.feature-item:hover {
    transform: scale(1.05);
}

.feature-item img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    margin-bottom: 10px;
}

.feature-item h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.feature-item p {
    font-size: 0.9rem;
    color: #cccccc;
}

/* 内容展示区域 */
.content {
    margin-top: 20px;
    padding: 20px;
    background: linear-gradient(to bottom, #00001a, #000000);
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}

.content h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: #00ff99;
}

.content pre {
    background: #000033;
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: #ffffff;
}

.content code {
    color: #00ff99;
}

/* 动画效果 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 1s ease-in-out;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar .menu {
        flex-direction: column;
        gap: 10px;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1.2rem;
    }

    .features {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }

    .content h2 {
        font-size: 1.5rem;
    }
}