/* 全局样式 */
body {
    margin: 0;
    padding: 0;
    font-family: 'Poppins', 'Nunito', sans-serif;
    background: linear-gradient(135deg, #2E7D32, #81C784);
    background-size: 400% 400%;
    animation: gradient-shimmer 15s ease infinite;
    color: #333;
    line-height: 1.6;
}
@keyframes gradient-shimmer {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

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

/* 头部 */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    position: relative;
}
header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
    opacity: 0.1;
    z-index: -1;
}
.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #fff;
}
nav ul {
    list-style: none;
    display: flex;
    gap: 15px;
}
nav ul li a {
    text-decoration: none;
    color: #fff;
    position: relative;
    transition: all 0.3s ease;
}
nav ul li a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #ffeb3b;
    transition: width 0.3s ease;
}
nav ul li a:hover {
    transform: scale(1.1);
}
nav ul li a:hover::after {
    width: 100%;
}

/* 主内容 */
main {
    display: flex;
    flex-direction: column;
    gap: 40px;
    padding: 20px 0;
}
section {
    background: rgba(255, 255, 255, 0.8);
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
}
section h2 {
    font-size: 2rem;
    margin-bottom: 15px;
    color: #2E7D32;
}
section p {
    font-size: 1rem;
    margin-bottom: 15px;
}
section img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
}
code, pre {
    background: #f5f5f5;
    padding: 10px;
    border-radius: 5px;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
}
pre {
    margin: 15px 0;
}
.article-example {
    border: 2px dashed #FFEB3B;
    padding: 20px;
    border-radius: 10px;
    background: rgba(255, 235, 59, 0.1);
}
.article-example h2 {
    color: #FFEB3B;
}
.article-example pre {
    background: #fff3e0;
    border-left: 5px solid #FF9800;
}
.article-example svg {
    max-width: 100px;
    height: auto;
}
.feature-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}
.feature-item {
    background: rgba(255, 255, 255, 0.9);
    border-radius: 10px;
    padding: 15px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.feature-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.2);
}
.feature-item img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    border-radius: 10px 10px 0 0;
}
.feature-item h3 {
    margin: 10px 0;
    color: #2E7D32;
}
.feature-item p {
    font-size: 0.95rem;
}
.footer {
    text-align: center;
    padding: 20px 0;
    color: #fff;
    background: rgba(46, 125, 50, 0.8);
    border-top: 2px solid #81C784;
}
.footer p {
    margin: 0;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 1440px) {
    .container {
        max-width: 1000px;
    }
}
@media (max-width: 1200px) {
    .container {
        max-width: 900px;
    }
}
@media (max-width: 1024px) {
    nav ul {
        flex-direction: column;
        gap: 10px;
    }
}
@media (max-width: 768px) {
    header, main, footer {
        padding: 10px;
    }
    .feature-list {
        grid-template-columns: 1fr;
    }
}
@media (max-width: 480px) {
    .logo {
        font-size: 1.2rem;
    }
    nav ul li a {
        font-size: 0.9rem;
    }
    section h2 {
        font-size: 1.5rem;
    }
}
@media (max-width: 320px) {
    .feature-item img {
        height: 120px;
    }
    section p, .feature-item p {
        font-size: 0.85rem;
    }
}