/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, #0A1A2F, #2196F3);
    color: #E0E0E0;
    line-height: 1.6;
    overflow-x: hidden;
}
h1, h2, h3 {
    font-weight: bold;
    color: #9C27B0;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}
p {
    font-size: 1rem;
    margin-bottom: 1rem;
}
a {
    color: #2196F3;
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}

/* 头部区域 */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(10, 26, 47, 0.8);
    z-index: 1000;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
header .logo {
    font-size: 1.5rem;
    color: #E0E0E0;
    font-weight: bold;
}
header nav ul {
    list-style: none;
    display: flex;
    gap: 1rem;
}
header nav ul li a {
    color: #E0E0E0;
    transition: color 0.3s ease;
}
header nav ul li a:hover {
    color: #9C27B0;
}

/* 主视觉区 */
.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: white;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center/cover, linear-gradient(45deg, #0A1A2F, #2196F3);
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
}
.hero h1 {
    font-size: 3rem;
    z-index: 1;
    text-transform: uppercase;
}
.hero p {
    font-size: 1.2rem;
    max-width: 600px;
    margin-top: 1rem;
    z-index: 1;
}

/* 内容模块 */
.section {
    padding: 4rem 2rem;
    background: #0A1A2F;
    position: relative;
}
.section:nth-child(even) {
    background: #1A2A3F;
}
.section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
}
.section .content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}
.section img {
    width: 100%;
    height: auto;
    border-radius: 10px;
}
.section pre {
    background: #2196F3;
    padding: 1rem;
    border-radius: 5px;
    overflow-x: auto;
}
.section code {
    color: #E0E0E0;
    font-family: 'Courier New', monospace;
}

/* 动画效果 */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.fade-in-up {
    animation: fadeInUp 1s ease-in-out;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    .section .content {
        grid-template-columns: 1fr;
    }
}
@media (max-width: 480px) {
    header nav ul {
        flex-direction: column;
        gap: 0.5rem;
    }
}