:root {
  --paper: #f4f1e8;
  --sheet: #fbf9f3;
  --ink: #1d2024;
  --muted: #5d6065;
  --rule: #cfc9b8;
  --grid: rgba(29, 32, 36, .045);
  --seal: #c8402a;
  --seal-text: #b03521;
  --term: #181a1f;
  --term-ink: #e6e3da;
  --term-dim: #8f939b;
  --term-accent: #f0a48f;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, "Hiragino Sans", "Noto Sans CJK JP", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #16181c;
    --sheet: #1d2025;
    --ink: #ece9e0;
    --muted: #a3a6ac;
    --rule: #363a41;
    --grid: rgba(236, 233, 224, .035);
    --seal: #d6502f;
    --seal-text: #f0876d;
    --term: #0f1114;
  }
}

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

html { scroll-behavior: smooth; scroll-padding-top: 72px; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 24px 24px;
  font: 17px/1.6 var(--sans);
}

a { color: inherit; text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: var(--seal-text); }
:focus-visible { outline: 2px solid var(--seal-text); outline-offset: 2px; }
code { font-family: var(--mono); font-size: .88em; overflow-wrap: anywhere; }

.wrap { width: min(1120px, 100%); margin: 0 auto; padding: 0 24px; }

.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 12px; z-index: 10; padding: 6px 12px; background: var(--sheet); }

/* Masthead */
.masthead {
  position: sticky; top: 0; z-index: 5;
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
}
.masthead-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 60px; }
.wordmark { display: inline-flex; align-items: center; gap: 10px; font: 600 16px var(--mono); text-decoration: none; }
.seal { display: block; width: 26px; height: 26px; }
.masthead nav { display: flex; gap: 22px; font-size: 15px; }
.masthead nav a { text-decoration: none; white-space: nowrap; }
.masthead nav a:hover { text-decoration: underline; }

/* Shared section furniture */
.label {
  margin: 0 0 14px;
  color: var(--seal-text);
  font: 600 13px var(--mono);
  letter-spacing: .08em;
  text-transform: uppercase;
}
.section { padding: 88px 0 0; }
.section h2 {
  max-width: 22ch;
  margin: 0 0 18px;
  font-size: clamp(30px, 4.4vw, 44px);
  line-height: 1.12;
  letter-spacing: -.02em;
}
.lede { max-width: 62ch; margin: 0; color: var(--muted); }

/* Hero */
.hero { padding: 88px 0 0; }
.hero h1 {
  max-width: 13ch;
  margin: 0 0 24px;
  font-size: clamp(44px, 8vw, 88px);
  line-height: 1;
  letter-spacing: -.035em;
}
.hero .lede { font-size: clamp(18px, 2.2vw, 21px); line-height: 1.5; }
.hero-install { max-width: 680px; margin-top: 36px; display: grid; gap: 10px; }
.note { margin: 12px 0 0; color: var(--muted); font-size: 15px; }

/* Command blocks */
.cmd {
  position: relative;
  display: flex; align-items: center;
  min-height: 48px;
  padding: 10px 76px 10px 16px;
  border-radius: 6px;
  background: var(--term);
  color: var(--term-ink);
  font: 14px/1.5 var(--mono);
  overflow-wrap: anywhere;
}
.cmd::before { content: "$"; flex: none; margin-right: 10px; color: var(--term-dim); user-select: none; }
.copy {
  position: absolute; top: 9px; right: 9px;
  min-width: 56px; padding: 4px 8px;
  border: 1px solid #454952; border-radius: 4px;
  background: transparent; color: var(--term-ink);
  font: 12px var(--mono); cursor: pointer;
}
.copy:hover { border-color: var(--term-ink); }

/* Toolchain diagram */
.chain {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 118px minmax(0, 1fr) 118px minmax(0, 1fr);
  align-items: center;
  margin-top: 40px;
}
.node {
  display: block;
  padding: 16px 18px;
  border: 1px solid var(--ink);
  border-radius: 4px;
  background: var(--sheet);
  text-decoration: none;
}
.node strong { display: block; font: 600 18px var(--mono); }
.node span { display: block; color: var(--muted); font-size: 14px; line-height: 1.35; }
.node-stack { display: grid; gap: 10px; }
.edge { position: relative; padding: 0 8px 12px; color: var(--muted); font: 12px var(--mono); text-align: center; }
.edge::after {
  content: ""; position: absolute; left: 6px; right: 6px; bottom: 4px;
  border-top: 1px solid var(--ink);
}
.edge::before {
  content: ""; position: absolute; right: 6px; bottom: 1px;
  width: 7px; height: 7px;
  border-top: 1px solid var(--ink); border-right: 1px solid var(--ink);
  transform: rotate(45deg);
}

/* Walkthrough */
.step {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
  gap: 40px;
  padding: 40px 0;
  border-top: 1px solid var(--rule);
}
.steps { margin-top: 56px; }
.step h3 { margin: 0 0 10px; font-size: 22px; line-height: 1.25; }
.step p { margin: 0; color: var(--muted); }
.step-no { display: block; margin-bottom: 10px; color: var(--seal-text); font: 600 13px var(--mono); }
.term {
  color-scheme: dark;
  margin: 0;
  padding: 18px 20px;
  border-radius: 6px;
  background: var(--term);
  color: var(--term-ink);
  font: 13.5px/1.65 var(--mono);
  overflow-x: auto;
  tab-size: 2;
}
.term .p { color: var(--term-accent); }
.term .d, .term .c { color: var(--term-dim); }
.term .c { font-style: italic; }

/* Tools */
.sheets {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  margin-top: 40px;
  border: 1px solid var(--ink);
  background: var(--sheet);
}
.sheet {
  display: flex; flex-direction: column;
  min-width: 0;
  padding: 28px;
  border-right: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  scroll-margin-top: 72px;
}
.sheet:nth-child(2n) { border-right: 0; }
.sheet:nth-last-child(-n + 2) { border-bottom: 0; }
.sheet-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; }
.sheet h3 { margin: 0; font: 600 26px var(--mono); }
.kanji { color: var(--seal-text); font-size: 26px; font-weight: 700; white-space: nowrap; }
.gloss { margin: 2px 0 14px; color: var(--muted); font: 13px var(--mono); }
.sheet > p { margin: 0 0 14px; }
.sheet ul { margin: 0 0 22px; padding-left: 18px; color: var(--muted); font-size: 15.5px; }
.sheet li { margin-bottom: 4px; }
.sheet .cmd { margin-top: auto; font-size: 12.5px; }
.sheet-link { margin-top: 12px; font-size: 15px; }

/* Method */
.method { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: 48px; align-items: start; }
.method p { margin: 0 0 16px; color: var(--muted); }

/* Close */
.close { padding: 88px 0; }
.close-box { padding: 40px; border: 1px solid var(--ink); background: var(--sheet); }
.close-box h2 { margin-bottom: 20px; }
.close-box .hero-install { margin-top: 0; }

.colophon { border-top: 1px solid var(--rule); background: var(--paper); font-size: 15px; color: var(--muted); }
.colophon-row { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px; padding-top: 22px; padding-bottom: 22px; }

@media (max-width: 860px) {
  .step, .method { grid-template-columns: minmax(0, 1fr); gap: 20px; }
  .chain { grid-template-columns: minmax(0, 1fr); max-width: 420px; }
  .edge { padding: 10px 0 10px 28px; text-align: left; }
  .edge::after { left: 12px; right: auto; top: 4px; bottom: 4px; border-top: 0; border-left: 1px solid var(--ink); }
  .edge::before { left: 9px; right: auto; bottom: 3px; transform: rotate(135deg); }
  .sheets { grid-template-columns: minmax(0, 1fr); }
  .sheet { border-right: 0; }
  .sheet:nth-last-child(2) { border-bottom: 1px solid var(--rule); }
}

@media (max-width: 560px) {
  body { font-size: 16px; }
  .wrap { padding: 0 16px; }
  .hero { padding-top: 56px; }
  .section { padding-top: 64px; }
  .masthead nav { gap: 14px; font-size: 14px; }
  .sheet { padding: 22px 18px; }
  .close { padding: 64px 0; }
  .close-box { padding: 24px 18px; }
  .cmd { padding-right: 16px; padding-top: 44px; }
  .sheet .cmd { font-size: 12px; }
  .term { padding: 14px; font-size: 12.5px; }
}

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

/* Long commands break at <wbr>, never mid-word. */
.cmd code { overflow-wrap: normal; }
@media (max-width: 560px) {
  .cmd { align-items: flex-start; }
}