/* ===== style.css 公用样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    background: #f1f5f9;
    font-family: system-ui, sans-serif;
    padding: 1.2rem;
    max-width: 1100px;
    margin: 0 auto;
    color: #1e293b;
    line-height: 1.6;
}

/* 卡片通用 */
header,
nav,
article,
aside section,
footer,
main,
section {
    background: #fff;
    border-radius: 0.6rem;
    padding: 0.6rem 1rem;
    border: 1px solid #e2e8f0;
}
header,
nav,
footer,
main {
    margin-bottom: 1rem;
}

/* 页眉 */
header {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.2rem;
}
header h1 {
    font-size: 1.4rem;
}
header p {
    font-size: 0.9rem;
    color: #64748b;
    margin-top: 0.1rem;
}
.back {
    color: #d97706;
    text-decoration: none;
    font-size: 0.8rem;
}
.back:hover {
    text-decoration: underline;
}

/* 导航 */
nav {
    display: flex;
    gap: 0.3rem;
    flex-wrap: wrap;
    padding: 0.4rem 0.6rem;
    background: #f8fafc;
}
nav a {
    text-decoration: none;
    color: #334155;
    padding: 0.3rem 0.8rem;
    border-radius: 0.4rem;
    font-weight: 500;
    font-size: 0.9rem;
    transition: 0.1s;
}
nav a:hover {
    background: #e2e8f0;
}
nav a.active {
    background: #d97706;
    color: #fff;
}

/* 主区域：两栏 */
main {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1rem;
    padding: 1rem;
}
main small {
    grid-column: 1 / -1;
    margin-bottom: 0.2rem;
}
main > section {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    background: transparent;
    border: 0;
    padding: 0;
}

/* article 通用 */
article h2 {
    font-size: 1.5rem;
}
article h3 {
    font-size: 1.1rem;
    margin: 0.8rem 0 0.2rem;
}
article h4 {
    font-size: 1rem;
    margin: 0.6rem 0 0.1rem;
}
article p {
    font-size: 1rem;
    margin-bottom: 0.6rem;
}
article pre {
    background: #f1f5f9;
    padding: 0.5rem 0.8rem;
    border-radius: 0.4rem;
    font-size: 0.8rem;
    overflow-x: auto;
    margin: 0.3rem 0 0.5rem;
}
article pre code {
    background: transparent;
    padding: 0;
    font-size: 0.8rem;
}
article ul,
aside ul {
    list-style: none;
    margin: 0.2rem 0 0.4rem;
}
article ul li,
aside ul li {
    font-size: 0.95rem;
    padding: 0.1rem 0;
    border-bottom: 1px solid #f1f5f9;
}

/* 小标签 */
small {
    display: inline-block;
    background: #dbeafe;
    padding: 0.1rem 0.6rem;
    border-radius: 40px;
    font-size: 0.6rem;
    font-weight: 700;
    color: #1e40af;
}

/* 侧边栏 */
aside {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}
aside section {
    padding: 0.6rem 1rem;
}
aside h3 {
    font-size: 1rem;
    margin-bottom: 0.2rem;
    border-bottom: 2px solid #f1f5f9;
    padding-bottom: 0.2rem;
}

/* 首页卡片 */
.grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 1rem;
}
.card {
    background: #fff;
    border-radius: 0.6rem;
    padding: 1.2rem 1rem;
    border: 1px solid #e2e8f0;
    text-align: center;
    transition: 0.15s;
    text-decoration: none;
    color: inherit;
    display: block;
}
.card:hover {
    border-color: #d97706;
    background: #fefaf5;
}
.card .icon {
    font-size: 2.4rem;
    display: block;
    margin-bottom: 0.2rem;
}
.card h2 {
    font-size: 1.2rem;
}
.card p {
    font-size: 0.85rem;
    color: #64748b;
}

/* 页脚 */
footer {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-size: 0.65rem;
    color: #64748b;
}
footer p {
    margin: 0;
}

/* 响应式 */
@media (max-width: 780px) {
    main {
        grid-template-columns: 1fr;
    }
    .grid {
        grid-template-columns: 1fr;
    }
    header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.3rem;
    }
    nav {
        gap: 0.3rem;
        font-size: 0.8rem;
    }
    nav a {
        padding: 0.2rem 0.5rem;
        font-size: 0.8rem;
    }
}