@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
  --paper: #fdfbf7;
  --paper-2: #f5f5f5;
  --ink: #1a1a1a;
  --line: #e0e0e0;
  --dot: #c9c4bb;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: "IBM Plex Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --serif: "Songti SC", "Source Han Serif SC", Georgia, "Times New Roman", serif;
}

*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.75;
  padding-bottom: 168px;
  overflow-x: hidden;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 70;
  pointer-events: none;
  opacity: .1;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}

a { color: var(--ink); }

:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

.mark {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 60;
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  background: var(--paper);
  border: 1.5px solid var(--ink);
  color: var(--ink);
  text-decoration: none;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 22px;
  line-height: 1;
}

.mark img {
  width: 32px;
  height: 32px;
  object-fit: contain;
  display: block;
}

.dock {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 50;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas:
    "nav nav"
    "find groups";
  gap: 6px 10px;
  padding: 8px 12px 10px;
  background: var(--paper);
  border-top: 1.5px solid var(--ink);
}

.dock-nav { grid-area: nav; min-width: 0; }

.dock-nav p {
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.dock-nav p::-webkit-scrollbar { display: none; }

.dock-nav a {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 12px;
  font-family: var(--mono);
  font-size: 16px;
  font-weight: 500;
  color: var(--ink);
  text-decoration: none;
  border: 1px solid transparent;
  white-space: nowrap;
}

.dock-nav a:hover,
.dock-nav a:focus-visible {
  border-color: var(--ink);
  background: var(--paper-2);
}

.find {
  grid-area: find;
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
}

.find-lab {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 16px;
}

.find input {
  flex: 1 1 auto;
  min-width: 0;
  height: 42px;
  padding: 0 10px;
  font-family: var(--sans);
  font-size: 16px;
  color: var(--ink);
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 0;
  appearance: none;
}

.find input:focus { background: var(--paper); }

.groups { grid-area: groups; position: relative; }

.groups summary {
  list-style: none;
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 14px;
  border: 1.5px solid var(--ink);
  font-family: var(--mono);
  font-size: 16px;
  cursor: pointer;
  user-select: none;
}

.groups summary::-webkit-details-marker { display: none; }

.grp-wrap {
  position: absolute;
  right: 0;
  bottom: calc(100% + 8px);
  width: min(80vw, 320px);
  padding: 12px;
  display: grid;
  gap: 12px;
  background: var(--paper);
  border: 1.5px solid var(--ink);
}

.grp-h {
  margin: 0 0 4px;
  font-family: var(--mono);
  font-size: 16px;
  letter-spacing: .05em;
}

.grp p {
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.grp a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 10px;
  background: var(--paper-2);
  color: var(--ink);
  text-decoration: none;
  font-size: 16px;
}

.grp a:hover,
.grp a:focus-visible {
  background: var(--ink);
  color: var(--paper);
}

.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 22px;
  padding: 120px 20px 190px;
  border-bottom: 1.5px solid var(--ink);
  background-image: radial-gradient(var(--dot) 1.2px, transparent 1.2px);
  background-size: 15px 15px;
  background-position: 0 0;
  scroll-margin-top: 84px;
}

.hero h1 {
  margin: 0;
  max-width: 15ch;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(2.1rem, 8.6vw, 5rem);
  line-height: 1.04;
  letter-spacing: -.035em;
}

.hero-lead {
  margin: 0;
  max-width: 46ch;
  padding: 2px 0;
  font-size: 18px;
  line-height: 1.8;
  color: #33312e;
  background: var(--paper);
}

.read {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  max-width: 1080px;
  margin: 0 auto;
  padding: 44px 20px 56px;
}

.rail { order: 1; }

.prose { order: 2; min-width: 0; }

.plate { order: 3; }

.rail {
  border-top: 1.5px solid var(--ink);
  padding-top: 10px;
  margin-bottom: 30px;
}

.rail-h {
  margin: 0;
  font-family: var(--mono);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .08em;
}

.subtitle {
  margin: 2px 0 14px;
  font-family: var(--mono);
  font-size: 16px;
  color: #5a574f;
}

.rail-list {
  list-style: none;
  counter-reset: r;
  margin: 0;
  padding: 0;
}

.rail-list li { counter-increment: r; }

.rail-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 42px;
  padding: 0 6px;
  color: var(--ink);
  text-decoration: none;
  font-size: 16px;
  border-bottom: 1px solid var(--line);
}

.rail-list a::before {
  content: counter(r, decimal-leading-zero);
  font-family: var(--mono);
  font-size: 16px;
  color: #7a766c;
}

.rail-list a:hover { background: var(--paper-2); }

.prose {
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.9;
  overflow-wrap: break-word;
}

.prose article {
  border-top: 1px solid var(--line);
  padding-bottom: 4px;
  scroll-margin-top: 96px;
}

.prose article:first-child { border-top: 0; }

.prose h2 {
  margin: 34px 0 14px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(1.35rem, 3.4vw, 1.9rem);
  line-height: 1.28;
  letter-spacing: -.02em;
}

.prose h3 {
  margin: 26px 0 12px;
  font-family: var(--sans);
  font-size: 19px;
  line-height: 1.4;
}

.prose p { margin: 0 0 18px; }

.prose ul,
.prose ol { margin: 0 0 18px; padding-left: 1.3em; }

.prose li { margin: 0 0 8px; }

.prose a {
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.prose blockquote {
  margin: 0 0 18px;
  padding: 12px 16px;
  background: var(--paper-2);
  border-left: 3px solid var(--ink);
}

.prose figure { margin: 0 0 18px; }

.prose img {
  display: block;
  max-width: 100%;
  height: auto;
}

.js .prose > article { opacity: 0; }

.js .prose > article.seen { opacity: 1; }

.plate {
  margin: 44px 0 0;
  padding: 16px;
  background: var(--paper-2);
  border: 1.5px solid var(--ink);
}

.plate-grid {
  height: 128px;
  background-image: radial-gradient(var(--ink) 1.4px, transparent 1.4px);
  background-size: 12px 12px;
  opacity: .85;
}

.plate figcaption {
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 16px;
  letter-spacing: .04em;
}

.foot {
  margin-top: 24px;
  padding: 36px 20px 26px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  background: var(--paper-2);
  border-top: 1.5px solid var(--ink);
}

.foot article { min-width: 0; }

.foot-mark {
  margin: 0;
  font-family: var(--mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -.02em;
}

.foot-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 8px;
}

.foot-list a {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 6px;
  font-family: var(--mono);
  font-size: 16px;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.foot-list a:hover { background: var(--paper); }

.top {
  min-height: 44px;
  padding: 0 16px;
  font-family: var(--mono);
  font-size: 16px;
  color: var(--ink);
  background: var(--paper);
  border: 1.5px solid var(--ink);
  cursor: pointer;
}

.top:hover { background: var(--ink); color: var(--paper); }

.copy {
  grid-column: 1 / -1;
  margin: 0;
  padding-top: 14px;
  text-align: center;
  font-size: 16px;
  color: #4a4741;
  border-top: 1px solid var(--line);
}

@media (min-width: 760px) {
  .foot {
    grid-template-columns: 1.1fr 1fr 1fr;
    align-items: start;
    max-width: 1080px;
    margin: 44px auto 0;
  }
}

@media (min-width: 820px) {
  .read {
    grid-template-columns: 200px minmax(0, 1fr);
    column-gap: 48px;
    padding-top: 64px;
  }

  .rail {
    grid-column: 1;
    grid-row: 1 / span 2;
    position: sticky;
    top: 84px;
    align-self: start;
    margin-bottom: 0;
  }

  .prose {
    grid-column: 2;
    grid-row: 1;
  }

  .plate {
    grid-column: 2;
    grid-row: 2;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .prose > article { opacity: 1; }
}

button[aria-expanded]{min-width:44px;min-height:44px}