:root {
  --paper: #fbf9f5;
  --card: #fffefb;
  --ink: #22272e;
  --muted: #6c727c;
  --line: #e6e0d6;
  --accent: #2c6e63;
  --accent-soft: #eef4f2;
  --radius: 10px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.8;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 760px; margin: 0 auto; padding: 0 22px; }

/* 顶部导航 */
.site-header {
  border-bottom: 1px solid var(--line);
  background: rgba(251, 249, 245, 0.94);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 64px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--ink);
}
.brand:hover { text-decoration: none; }
.brand svg { width: 22px; height: 22px; }
.nav { display: flex; gap: 22px; font-size: 15px; }
.nav a { color: var(--muted); }
.nav a:hover { color: var(--ink); text-decoration: none; }
.nav a[aria-current="page"] { color: var(--ink); }

/* 首页头部 */
.hero { padding: 54px 0 6px; }
.hero h1 {
  font-family: Georgia, "Songti SC", "Noto Serif SC", serif;
  font-size: 32px;
  line-height: 1.35;
  font-weight: 600;
  margin: 0 0 14px;
}
.hero p { color: var(--muted); margin: 0; max-width: 36em; }

/* 分区标题 */
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin: 46px 0 4px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}
.section-head h2 { font-size: 17px; font-weight: 600; letter-spacing: 0.04em; margin: 0; }
.section-head span { font-size: 13px; color: var(--muted); }

/* 笔记列表 */
.note-list { list-style: none; margin: 0; padding: 0; }
.note-list li { padding: 20px 0; border-bottom: 1px dashed var(--line); }
.note-list li:last-child { border-bottom: none; }
.note-list h3 { margin: 0 0 6px; font-size: 18px; font-weight: 600; line-height: 1.55; }
.note-list h3 a { color: var(--ink); }
.note-list h3 a:hover { color: var(--accent); text-decoration: none; }
.excerpt { margin: 8px 0 0; color: var(--muted); font-size: 15px; }

.meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 13px;
  color: var(--muted);
}
.meta .tag {
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 4px;
  padding: 1px 8px;
  font-size: 12px;
}

/* 说明卡片 */
.about-box {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 22px;
  margin: 18px 0 0;
  font-size: 15px;
  color: var(--muted);
}
.about-box p { margin: 0 0 10px; }
.about-box p:last-child { margin: 0; }

/* 文章正文 */
.article-head { padding: 44px 0 4px; }
.article-head h1 {
  font-family: Georgia, "Songti SC", "Noto Serif SC", serif;
  font-size: 28px;
  line-height: 1.45;
  font-weight: 600;
  margin: 0 0 12px;
}
.article-body { padding-top: 6px; }
.article-body p { margin: 0 0 18px; }
.article-body h2 {
  font-size: 19px;
  font-weight: 600;
  margin: 34px 0 12px;
  padding-left: 11px;
  border-left: 3px solid var(--accent);
  line-height: 1.5;
}
.article-body ul,
.article-body ol { margin: 0 0 18px; padding-left: 1.4em; }
.article-body li { margin: 5px 0; }
.article-body blockquote {
  margin: 0 0 18px;
  padding: 2px 16px;
  border-left: 3px solid var(--line);
  color: var(--muted);
}
.article-body code {
  background: #f2efe9;
  padding: 0.1em 0.35em;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
}
.article-body pre {
  background: #23282d;
  color: #e8e8e8;
  padding: 14px 16px;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.65;
  margin: 0 0 18px;
}
.article-body pre code { background: none; padding: 0; color: inherit; }

.backlink { margin: 40px 0 0; font-size: 14px; }

/* 页脚 */
.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 64px;
  padding: 26px 0 42px;
  font-size: 13px;
  color: var(--muted);
  line-height: 2;
}
.site-footer p { margin: 0; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--accent); }

@media (max-width: 640px) {
  .site-header .wrap {
    height: auto;
    padding-top: 12px;
    padding-bottom: 12px;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  .nav { gap: 18px; }
  .hero { padding: 34px 0 4px; }
  .hero h1 { font-size: 26px; }
  .article-head { padding: 30px 0 2px; }
  .article-head h1 { font-size: 23px; }
}