/* ═══════════════════════════════════════════════════════════════
   李玉鑫 · 个人主页
   极简文字流 + 左侧固定目录 + 顶部项目跳转
   ═══════════════════════════════════════════════════════════════ */

:root {
  --bg: #fbfbf9;
  --ink: #16171b;
  --ink-2: #3f4148;
  --muted: #71737b;
  --faint: #9a9ca4;
  --line: #e3e3df;
  --line-soft: #eeeeea;
  --accent: #1f5fd0;
  --maxw: 1016px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --topbar-h: 57px;
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--topbar-h) + 16px);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto,
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  font-size: 16px;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
a:hover { color: var(--accent); }
img { max-width: 100%; display: block; }
ul, ol, dl, dd { margin: 0; padding: 0; }
ul, ol { list-style: none; }

code {
  font-family: var(--mono);
  font-size: .875em;
  background: #f1f1ed;
  padding: 1px 5px;
  border-radius: 3px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: #fff;
  padding: 10px 16px;
  z-index: 99;
}
.skip:focus { left: 12px; top: 12px; }

/* ─────────── 顶部固定栏 ─────────── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(251, 251, 249, .9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.topbar-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--topbar-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  font-weight: 600;
  letter-spacing: -.01em;
  font-size: 15px;
  white-space: nowrap;
}
.brand span { color: var(--faint); font-weight: 400; }

.topnav {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 13.5px;
  color: var(--muted);
  overflow-x: auto;
  scrollbar-width: none;
}
.topnav::-webkit-scrollbar { display: none; }

.topnav a { white-space: nowrap; }
.topnav a:hover { color: var(--ink); }

.topnav .proj-link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
}

.topnav .idx {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--faint);
}

.topnav .cv {
  color: var(--ink);
  padding: 4px 12px;
  border: 1px solid var(--line);
  border-radius: 4px;
}
.topnav .cv:hover { border-color: var(--ink); }

/* ─────────── 双栏布局 ─────────── */
.layout {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 158px minmax(0, 1fr);
  column-gap: 52px;
  align-items: start;
}

/* 左侧固定目录 */
.sidebar {
  position: sticky;
  top: var(--topbar-h);
  padding: 46px 0 40px;
  max-height: calc(100vh - var(--topbar-h));
  overflow-y: auto;
  scrollbar-width: none;
}
.sidebar::-webkit-scrollbar { display: none; }

.sb-title {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--faint);
  margin: 0 0 10px;
}

.sidebar nav a {
  display: block;
  padding: 5px 0 5px 12px;
  margin-left: -1px;
  border-left: 2px solid var(--line-soft);
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.6;
}

.sidebar nav a:hover { color: var(--ink); border-left-color: var(--faint); }
.sidebar nav a.active { color: var(--ink); border-left-color: var(--ink); font-weight: 500; }

.sidebar .sb-foot {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
  font-size: 12.5px;
  color: var(--faint);
}
.sidebar .sb-foot a { color: var(--muted); }
.sidebar .sb-foot a:hover { color: var(--ink); }

/* 右侧内容 */
.content {
  min-width: 0;
  padding: 46px 0 88px;
}

/* ─────────── 首屏 ─────────── */
.eyebrow {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 20px;
}

.intro-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 32px;
}

h1 {
  margin: 0 0 10px;
  font-size: clamp(30px, 5vw, 40px);
  line-height: 1.18;
  letter-spacing: -.028em;
  font-weight: 600;
}

.tagline {
  margin: 0;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--ink-2);
  max-width: 30em;
}

.portrait {
  flex: 0 0 auto;
  width: 100px;
  height: 125px;
  object-fit: cover;
  object-position: center 15%;
  border: 1px solid var(--line);
  border-radius: 3px;
  background: #f1f1ed;
}

.facts {
  display: flex;
  flex-wrap: wrap;
  gap: 7px 20px;
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
  font-size: 13.5px;
  color: var(--muted);
}

/* 移动端的内联目录 */
.toc {
  display: none;
  padding: 12px 0;
  border-top: 1px solid var(--line-soft);
  font-size: 13px;
  color: var(--faint);
  flex-wrap: wrap;
  gap: 6px 16px;
  margin-top: 16px;
}
.toc b { font-weight: 500; color: var(--muted); }
.toc a { color: var(--muted); }

/* ─────────── 章节 ─────────── */
section.doc {
  padding: 42px 0;
  border-top: 1px solid var(--line);
}

.num {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--faint);
  margin: 0 0 7px;
}

h2 {
  margin: 0 0 16px;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -.01em;
}

.lead {
  margin: 0 0 12px;
  color: var(--ink-2);
  font-size: 15.5px;
}

section.doc p { color: var(--ink-2); margin: 0 0 12px; }
section.doc p:last-child { margin-bottom: 0; }
section.doc strong { color: var(--ink); font-weight: 600; }

/* ─────────── 项目 ─────────── */
.proj {
  padding: 24px 0;
  border-top: 1px solid var(--line-soft);
}
.proj:first-of-type { border-top: none; padding-top: 2px; }

.proj-kicker {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--faint);
  margin: 0 0 10px;
}

.proj h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -.01em;
}

.proj-desc {
  margin: 0 0 16px;
  color: var(--ink-2);
  font-size: 15.5px;
}

.kv {
  display: grid;
  grid-template-columns: 92px 1fr;
  gap: 7px 18px;
  margin: 0 0 16px;
  font-size: 14.5px;
}

.kv dt {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--faint);
  padding-top: 2px;
}

.kv dd { color: var(--ink); margin: 0; }

.skill-row {
  display: grid;
  grid-template-columns: 126px 1fr;
  gap: 8px 18px;
  padding: 10px 0;
  border-top: 1px solid var(--line-soft);
  font-size: 14.8px;
}
.skill-row:first-of-type { border-top: none; padding-top: 2px; }
.skill-row dt { color: var(--muted); font-size: 14px; }
.skill-row dd { color: var(--ink-2); margin: 0; }

.contact-row {
  display: grid;
  grid-template-columns: 84px 1fr;
  gap: 8px 18px;
  padding: 8px 0;
  border-top: 1px solid var(--line-soft);
  font-size: 15px;
}
.contact-row:first-of-type { border-top: none; padding-top: 2px; }
.contact-row dt {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--faint);
  padding-top: 3px;
}
.contact-row dd { margin: 0; }
.contact-row dd a {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--line);
}
.contact-row dd a:hover { text-decoration-color: currentColor; }

.more {
  display: inline-block;
  font-size: 14.5px;
  color: var(--accent);
}
.more:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ─────────── 页脚 ─────────── */
footer.site {
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--faint);
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 22px 24px 40px;
  display: flex;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
}

/* 构建标记：用来一眼分辨浏览器缓存的是哪个版本 */
.build {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 400;
  color: #c3c4cb;
  margin-left: 6px;
}

footer.site a:hover { color: var(--ink); }

/* ─────────── 响应式 ─────────── */
@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
    column-gap: 0;
  }
  .sidebar { display: none; }
  .toc { display: flex; }
  .content { padding-top: 32px; }
}

@media (max-width: 680px) {
  body { font-size: 15.5px; }
  .topbar-inner, .layout, .footer-inner { padding-left: 18px; padding-right: 18px; }
  .brand span { display: none; }
  .topnav { gap: 14px; font-size: 13px; }
  .intro-head { gap: 18px; }
  .portrait { width: 74px; height: 92px; }
  section.doc { padding: 32px 0; }
  .kv, .skill-row, .contact-row { grid-template-columns: 1fr; gap: 2px; }
  .kv dt, .skill-row dt, .contact-row dt { padding-top: 7px; }
  .kv dd, .skill-row dd, .contact-row dd { padding-bottom: 3px; }
}

@media print {
  body { background: #fff; font-size: 12px; }
  .topbar, .sidebar, .toc, footer.site, .skip, .more { display: none; }
  .layout { grid-template-columns: 1fr; }
  section.doc { padding: 14px 0; }
  .proj { break-inside: avoid; }
}