:root {
  color-scheme: light dark;
  --paper: #f6f0e5;
  --ink: #29241f;
  --muted: #6e6256;
  --amber: #b96919;
  --line: #d9cbb9;
  --card: #efe6d7;
  --code-bg: #efe7da;
  --hl-kw: #9a4f0c;
  --hl-str: #5d6b2a;
  --hl-num: #8a3f55;
  --hl-com: #8c7f70;
  --hl-fn: #2f5f79;
  --sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  /* 西文用 Georgia；中文在 Mac 上用宋体，Windows 上宋体没有真粗体，退到雅黑 */
  --serif: Georgia, "Times New Roman", "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", "Microsoft YaHei", serif;
  --mono: "JetBrains Mono", "Cascadia Mono", Consolas, "SFMono-Regular", Menlo, "Microsoft YaHei Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #1d1a17;
    --ink: #eee4d6;
    --muted: #b9ab99;
    --line: #473e34;
    --amber: #dc8b39;
    --card: #26221e;
    --code-bg: #25211d;
    --hl-kw: #e9a15a;
    --hl-str: #b5c07a;
    --hl-num: #e08aa0;
    --hl-com: #8f8272;
    --hl-fn: #86b6cf;
  }
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 1rem/1.8 var(--sans);
}

a { color: inherit; text-decoration-color: var(--amber); text-underline-offset: .2em; }
a:hover { color: var(--amber); }

/* ---------- 首页 ---------- */
.home {
  width: min(42rem, 100%);
  margin: 0 auto;
  padding: clamp(3rem, 12vh, 7rem) 1rem 0;
}
.mark {
  width: 2.5rem;
  height: .28rem;
  margin-bottom: 1.8rem;
  background: var(--amber);
  border-radius: 999px;
}
.hero h1 {
  margin: 0;
  font: 500 clamp(2.8rem, 9vw, 5.8rem)/.95 var(--serif);
  letter-spacing: -.055em;
}
.tagline {
  max-width: 31rem;
  margin: 1.6rem 0 0;
  color: var(--muted);
  font-size: 1.05rem;
  line-height: 1.7;
}
.notes { margin-top: 4rem; }
.section-label {
  margin: 0 0 .5rem;
  padding-bottom: .6rem;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font: 500 .78rem/1.5 var(--sans);
  letter-spacing: .12em;
}

/* ---------- 笔记列表 ---------- */
.note-list { list-style: none; margin: 0; padding: 0; }
.note-list li { padding: 1.25rem 0; border-bottom: 1px solid var(--line); }
.note-list a {
  font: 600 1.18rem/1.45 var(--serif);
  text-decoration: none;
}
.note-list p { margin: .35rem 0 .45rem; color: var(--muted); font-size: .95rem; line-height: 1.7; }
.meta {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem .7rem;
  align-items: center;
  color: var(--muted);
  font-size: .8rem;
  line-height: 1.5;
}
.tag {
  padding: .05rem .5rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: .74rem;
}

/* ---------- 站点页眉页脚 ---------- */
.site-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  width: min(46rem, 100%);
  margin: 0 auto;
  padding: 1.4rem 1rem;
  font-size: .9rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  font: 600 1.05rem/1 var(--serif);
  letter-spacing: -.02em;
  text-decoration: none;
}
.brand-mark { width: 1.1rem; height: .2rem; background: var(--amber); border-radius: 999px; }
.site-head nav { display: flex; gap: 1.1rem; }
.site-head nav a { color: var(--muted); text-decoration: none; }
.site-head nav a:hover { color: var(--amber); }

.site-foot {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: .4rem 1.5rem;
  width: min(42rem, 100%);
  margin: 4.5rem auto 0;
  padding: 1rem 1rem 3rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .78rem;
  line-height: 1.6;
}
.site-foot span:first-child { letter-spacing: .08em; text-transform: uppercase; }
.home + .site-foot { margin-top: 3rem; }

/* ---------- 笔记列表页 ---------- */
.listing { width: min(42rem, 100%); margin: 0 auto; padding: 1.5rem 1rem 0; }
.listing h1 { margin: 0; font: 500 2.4rem/1.2 var(--serif); letter-spacing: -.03em; }
.lede { margin: .8rem 0 1.5rem; color: var(--muted); }

/* ---------- 单篇笔记 ---------- */
.note { width: min(42rem, 100%); margin: 0 auto; padding: 1rem 1rem 0; }
.note-head h1 {
  margin: 0 0 .8rem;
  font: 600 clamp(1.7rem, 5vw, 2.25rem)/1.3 var(--serif);
  letter-spacing: -.02em;
}
.note-head .meta { margin-bottom: 1.8rem; }

.toc {
  margin: 0 0 2.2rem;
  padding: 1rem 1.2rem;
  background: var(--card);
  border-radius: .6rem;
  font-size: .9rem;
}
.toc p { margin: 0 0 .3rem; color: var(--muted); font-size: .78rem; letter-spacing: .1em; }
.toc ol { margin: 0; padding-left: 1.3rem; }
.toc li { margin: .15rem 0; }
.toc a { text-decoration: none; }

.prose { overflow-wrap: break-word; }
.prose h2 {
  margin: 2.6rem 0 .8rem;
  font: 600 1.4rem/1.4 var(--serif);
  scroll-margin-top: 1rem;
}
.prose h3 { margin: 1.9rem 0 .6rem; font: 600 1.1rem/1.5 var(--sans); }
.prose p, .prose ul, .prose ol { margin: .9rem 0; }
.prose li { margin: .3rem 0; }
.prose li > p { margin: .3rem 0; }
.prose strong { font-weight: 650; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 2.5rem 0; }

.prose blockquote {
  margin: 1.3rem 0;
  padding: .7rem 1.1rem;
  border-left: 3px solid var(--amber);
  background: var(--card);
  border-radius: 0 .5rem .5rem 0;
  color: var(--ink);
}
.prose blockquote p { margin: .4rem 0; }

.prose :not(pre) > code {
  padding: .1em .35em;
  background: var(--code-bg);
  border-radius: .3em;
  font: .86em/1.5 var(--mono);
}
pre.code {
  margin: 1.2rem 0;
  padding: .9rem 1.1rem;
  overflow-x: auto;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: .5rem;
  font: .84rem/1.6 var(--mono);
  tab-size: 4;
}
pre.code code { font: inherit; }

.table-wrap { margin: 1.2rem 0; overflow-x: auto; }
.prose table { width: 100%; border-collapse: collapse; font-size: .9rem; line-height: 1.6; }
.prose th, .prose td { padding: .45rem .7rem; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.prose th { border-bottom: 2px solid var(--line); font-weight: 600; white-space: nowrap; }

.math-display, .katex-display { overflow-x: auto; overflow-y: hidden; }
.math-display { margin: 1.1rem 0; }
.katex { font-size: 1.08em; }

.prose figure { margin: 1.6rem 0; }
.prose figure img { display: block; width: 100%; height: auto; background: #fff; border-radius: .5rem; border: 1px solid var(--line); }
.prose figcaption { margin-top: .5rem; color: var(--muted); font-size: .85rem; line-height: 1.6; }

.refs { font-size: .9rem; }
.refs li { margin: .35rem 0; }

.pager {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
}
.pager a { text-decoration: none; font: 600 .98rem/1.5 var(--serif); }
.pager a span { display: block; color: var(--muted); font: .76rem/1.6 var(--sans); letter-spacing: .08em; }
.pager .next { text-align: right; }

/* ---------- 代码高亮（highlight.js 的类名） ---------- */
.hljs-keyword, .hljs-built_in, .hljs-selector-tag, .hljs-literal { color: var(--hl-kw); }
.hljs-string, .hljs-regexp, .hljs-addition { color: var(--hl-str); }
.hljs-number, .hljs-symbol, .hljs-variable, .hljs-template-variable { color: var(--hl-num); }
.hljs-comment, .hljs-quote, .hljs-meta { color: var(--hl-com); font-style: italic; }
.hljs-title, .hljs-title.function_, .hljs-function .hljs-title, .hljs-section { color: var(--hl-fn); }
.hljs-params, .hljs-attr { color: inherit; }

@media (max-width: 34rem) {
  body { font-size: .97rem; }
  .pager { grid-template-columns: 1fr; }
  .pager .next { text-align: left; }
  .site-head { padding: 1.1rem 1rem; }
}