* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    background: #f8f9fa;
    color: #24292f;
    line-height: 1.7;
    min-height: 100vh;
}

.content {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px 80px;
}

/* ---- 标题 ---- */
.content h1 { font-size: 2em; margin: 0 0 0.3em; font-weight: 700; border-bottom: 1px solid #d0d7de; padding-bottom: 0.3em; }
.content h2 { font-size: 1.5em; margin: 1.5em 0 0.5em; font-weight: 600; border-bottom: 1px solid #d0d7de; padding-bottom: 0.25em; }
.content h3 { font-size: 1.25em; margin: 1.2em 0 0.4em; font-weight: 600; }
.content h4 { font-size: 1em; margin: 1em 0 0.3em; font-weight: 600; }

/* ---- 段落和行内元素 ---- */
.content p { margin: 0 0 1em; }
.content a { color: #0969da; text-decoration: none; }
.content a:hover { text-decoration: underline; }
.content strong { font-weight: 600; }
.content code {
    background: #afb8c133;
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-size: 0.9em;
    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
}
.content del { color: #656d76; }

/* ---- 列表 ---- */
.content ul, .content ol { margin: 0 0 1em; padding-left: 2em; }
.content li { margin-bottom: 0.25em; }
.content li > ul, .content li > ol { margin-top: 0.25em; margin-bottom: 0; }

/* ---- 代码块 ---- */
.content pre {
    background: #1e1e2e;
    color: #cdd6f4;
    padding: 16px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 0 0 1em;
    font-size: 0.9em;
    line-height: 1.5;
}
.content pre code {
    background: none;
    padding: 0;
    border-radius: 0;
    font-size: inherit;
    color: inherit;
}

/* ---- 引用 ---- */
.content blockquote {
    border-left: 4px solid #0969da;
    margin: 0 0 1em;
    padding: 0.5em 1em;
    color: #656d76;
    background: #f6f8fa;
    border-radius: 0 4px 4px 0;
}
.content blockquote p:last-child { margin-bottom: 0; }

/* ---- 表格 ---- */
.content table {
    border-collapse: collapse;
    width: 100%;
    margin: 0 0 1em;
}
.content th, .content td {
    border: 1px solid #d0d7de;
    padding: 8px 13px;
    text-align: left;
}
.content th {
    background: #f6f8fa;
    font-weight: 600;
}
.content tr:nth-child(even) { background: #f6f8fa; }

/* ---- 图片 ---- */
.content img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
}

/* ---- 水平线 ---- */
.content hr {
    border: none;
    border-top: 1px solid #d0d7de;
    margin: 2em 0;
}

/* ---- 任务列表 ---- */
.content input[type="checkbox"] {
    margin-right: 0.4em;
}

/* ---- 响应式 ---- */
@media (max-width: 768px) {
    .content {
        padding: 24px 16px 60px;
    }
    .content h1 { font-size: 1.6em; }
    .content h2 { font-size: 1.3em; }
    .content h3 { font-size: 1.1em; }
    .content pre { padding: 12px; font-size: 0.85em; }
}