:root {
  color-scheme: light;
  --ink: #171a2b;
  --muted: #666d84;
  --line: #e2e5f0;
  --soft: #f5f6fb;
  --surface: #fff;
  --accent: #b45309;
  --accent-soft: #fdf3e6;
  --accent-line: #f0cd9c;
  --regen: #047857;
  --regen-soft: #e9f7f1;
  --regen-line: #a8dcc7;
  --bad: #b91c1c;
  --bad-soft: #fdeeee;
  --stage: #0e1220;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Yu Gothic UI", "Yu Gothic", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
}

* { box-sizing: border-box; }
html { background: #fff; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-size: 15px;
  line-height: 1.7;
}
h1, h2, h3 { line-height: 1.35; overflow-wrap: anywhere; }
button, input { font: inherit; color: inherit; }
button { cursor: pointer; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ---------------------------------------------------------- 共通の枠 */

.site-topbar {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  border-bottom: 1px solid var(--line);
}
.site-brand { display: flex; gap: 8px; align-items: center; color: inherit; font-weight: 800; text-decoration: none; }
.site-top-title { color: var(--muted); font-size: 12px; }

main { width: min(100%, 1140px); margin: 0 auto; padding: 0 16px 56px; }

.hero { padding: 40px 0 26px; }
.eyebrow { margin: 0 0 8px; color: var(--muted); font-size: 11px; font-weight: 700; letter-spacing: .12em; }
.hero h1 { margin: 0; font-size: clamp(27px, 6vw, 42px); letter-spacing: -.02em; }
.lead { margin: 14px 0 0; max-width: 68ch; color: #3c4254; }
.lead strong { color: var(--ink); background: linear-gradient(transparent 62%, var(--accent-soft) 62%); }

/* ------------------------------------------------------ シミュレーター */

.lab {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--soft);
}
.lab-head { display: flex; gap: 10px; align-items: center; justify-content: space-between; margin-bottom: 10px; flex-wrap: wrap; }

.tabs { display: flex; gap: 4px; padding: 3px; border: 1px solid var(--line); border-radius: 9px; background: var(--surface); }
.tabs button {
  min-height: 38px;
  padding: 6px 16px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}
.tabs button.on { background: var(--ink); color: #fff; }

.ghost {
  min-height: 40px;
  padding: 8px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  font-size: 13px;
  font-weight: 700;
}
.ghost:hover { border-color: #b8bfd2; background: #fff; }
.ghost:disabled { color: #aab; background: var(--soft); cursor: default; }
.ghost.small { min-height: 36px; padding: 6px 12px; font-size: 12.5px; }

.stage {
  overflow: hidden;
  border: 1px solid #222a3f;
  border-radius: 10px;
  background: var(--stage);
}
#scene { display: block; width: 100%; height: clamp(360px, 46vw, 500px); }
.canvas-alt { margin: 8px 2px 0; color: var(--muted); font-size: 11.5px; line-height: 1.6; }

.flags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; min-height: 4px; }
.flag {
  padding: 6px 11px;
  border: 1px solid var(--accent-line);
  border-radius: 999px;
  background: var(--accent-soft);
  color: #8a4409;
  font-size: 12px;
  font-weight: 700;
}
.flag.ok { border-color: var(--regen-line); background: var(--regen-soft); color: var(--regen); }
.flag.warn { border-color: #f2bcbc; background: var(--bad-soft); color: var(--bad); }

/* -------------------------------------------------------------- ガイド */

.guide {
  margin-top: 12px;
  padding: 14px 16px 12px;
  border: 1px solid var(--accent-line);
  border-radius: 11px;
  background: #fffaf3;
}
.guide-head { display: flex; align-items: center; justify-content: space-between; }
.guide-num { color: var(--accent); font-size: 12px; font-weight: 800; letter-spacing: .06em; }
.guide h2 { margin: 4px 0 6px; font-size: 17px; }
.guide p { margin: 0; color: #3c4254; font-size: 14px; }
.guide-nav { display: flex; gap: 10px; align-items: center; justify-content: space-between; margin-top: 12px; }
.dots { display: flex; flex-wrap: wrap; gap: 4px; justify-content: center; }
.dots button {
  width: 28px;
  height: 28px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--surface);
  color: var(--muted);
  font-size: 11.5px;
  font-weight: 700;
}
.dots button.on { border-color: var(--accent); background: var(--accent); color: #fff; }

/* -------------------------------------------------------------- 操作 */

.panels { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: 12px; margin-top: 12px; }
.panel { padding: 14px; border: 1px solid var(--line); border-radius: 11px; background: var(--surface); }
.panel h3 {
  margin: -14px -14px 12px;
  padding: 9px 14px;
  border-bottom: 1px solid var(--line);
  border-radius: 10px 10px 0 0;
  background: var(--soft);
  font-size: 13px;
  letter-spacing: .04em;
}

.drive { display: flex; gap: 14px; align-items: flex-start; }
.lever-wrap { display: flex; flex-direction: column; gap: 6px; flex: 0 0 auto; }
.cap { display: block; color: var(--muted); font-size: 11.5px; font-weight: 700; letter-spacing: .04em; }
.cap b { color: var(--ink); font-size: 13px; }
.hint { color: var(--muted); font-size: 10.5px; }

.lever { display: flex; flex-direction: column; gap: 3px; width: 86px; }
.notch {
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: #4a5164;
  font-size: 12.5px;
  font-weight: 700;
  transition: background .12s, border-color .12s, color .12s;
}
.notch:hover { border-color: #b8bfd2; }
.notch-p.on { border-color: var(--accent); background: var(--accent-soft); color: #8a4409; }
.notch-n.on { border-color: #9aa1b5; background: #eef0f6; color: var(--ink); }
.notch-b.on { border-color: var(--regen-line); background: var(--regen-soft); color: var(--regen); }

.drive-side { display: flex; flex-direction: column; gap: 12px; flex: 1; min-width: 0; }
.field { display: flex; flex-direction: column; gap: 5px; }
.seg { display: flex; gap: 5px; }
.seg button {
  flex: 1;
  min-height: 42px;
  padding: 6px 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: #4a5164;
  font-size: 13px;
  font-weight: 700;
}
.seg button.on { border-color: var(--ink); background: var(--ink); color: #fff; }

input[type=range] { width: 100%; height: 26px; accent-color: var(--accent); }
.scale { display: flex; justify-content: space-between; color: var(--muted); font-size: 10.5px; }
.field .note { margin: 2px 0 0; color: var(--muted); font-size: 10.5px; line-height: 1.5; }

.switches { gap: 8px; }
.sw { display: flex; gap: 8px; align-items: center; min-height: 34px; font-size: 13px; cursor: pointer; }
.sw input { width: 18px; height: 18px; accent-color: var(--accent); }

/* -------------------------------------------------------------- 計器 */

.gauges { display: grid; grid-template-columns: repeat(auto-fill, minmax(108px, 1fr)); gap: 7px; }
.g {
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 8px 9px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--soft);
}
.g-lg { grid-column: span 2; }
.gk { color: var(--muted); font-size: 10.5px; font-weight: 700; line-height: 1.4; }
.gv { display: flex; gap: 3px; align-items: baseline; }
.gv b { font-size: 19px; font-variant-numeric: tabular-nums; letter-spacing: -.01em; }
.g-lg .gv b { font-size: 26px; }
.gv i { color: var(--muted); font-size: 11px; font-style: normal; }
.sub { color: var(--muted); font-size: 11px; font-weight: 700; }
.sub.bad { color: var(--bad); }
.sub.good { color: var(--regen); }

/* --- 摩耗検査ラボ --- */

.crumbs { display: flex; flex-wrap: wrap; gap: 8px; padding-top: 16px; color: var(--muted); font-size: 12px; }
.crumbs a { color: var(--muted); }
.seg-wrap { flex-wrap: wrap; }
.seg-wrap button { flex: 1 1 auto; min-width: 62px; }
.row-btns { flex-direction: row; flex-wrap: wrap; gap: 8px; }
.row-btns .ghost { flex: 1 1 auto; }

.gv-b.good { color: var(--regen); }
.gv-b.bad { color: var(--bad); }

.verdict {
  margin: 10px 0 0;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--soft);
  font-size: 13px;
  font-weight: 700;
}
.verdict.ok { border-color: var(--regen-line); background: var(--regen-soft); color: var(--regen); }
.verdict.warn { border-color: var(--accent-line); background: var(--accent-soft); color: #8a4409; }
.verdict.bad { border-color: #f2bcbc; background: var(--bad-soft); color: var(--bad); }

.conv, .spot {
  margin-top: 12px;
  padding: 12px;
  border: 1px solid var(--accent-line);
  border-radius: 9px;
  background: #fffaf3;
}
.conv h4, .spot h4 { margin: 0 0 8px; font-size: 13px; }
.sub-head { margin: 14px 0 7px; color: var(--muted); font-size: 11.5px; font-weight: 700; letter-spacing: .03em; }
.stage-tall #scene { height: clamp(430px, 46vw, 580px); }
.spot p { margin: 0; color: #3c4254; font-size: 13px; }
.conv .sub { display: block; margin-top: 8px; color: #6b5233; font-weight: 400; line-height: 1.6; }

.doc-links { margin-top: 34px; }
.doc-links ul { padding-left: 20px; }
.doc-links li { margin-bottom: 8px; }

.brake { margin-top: 10px; }
.brake-bar {
  --e: 0%;
  height: 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: linear-gradient(to right, var(--regen) 0 var(--e), #cdd3e2 var(--e) 100%);
}
.brake .sub { display: block; margin-top: 4px; }
.spec { margin: 10px 0 0; color: var(--muted); font-size: 11.5px; }

/* -------------------------------------------------------------- 解説 */

.doc { max-width: 74ch; margin: 44px auto 0; }
.doc h2 {
  margin: 40px 0 12px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 20px;
  letter-spacing: -.01em;
}
.doc h2:first-child { margin-top: 8px; border-top: 0; padding-top: 0; }
.doc p { margin: 0 0 14px; }
.doc-note {
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: var(--soft);
  color: var(--muted);
  font-size: 13.5px;
}
.doc-table { width: 100%; margin: 16px 0 20px; border-collapse: collapse; font-size: 13.5px; }
.doc-table th, .doc-table td { padding: 9px 11px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.doc-table th { background: var(--soft); font-weight: 700; }
.doc-table tr td:first-child { font-weight: 700; white-space: nowrap; }
.doc dl { margin: 16px 0 0; }
.doc dt { margin-top: 14px; font-weight: 700; }
.doc dt::before { content: ""; display: inline-block; width: 6px; height: 6px; margin-right: 8px; border-radius: 2px; background: var(--accent); vertical-align: middle; }
.doc dd { margin: 2px 0 0 14px; color: #3c4254; font-size: 14px; }

.site-foot { padding: 24px 16px 34px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12.5px; text-align: center; }
.site-foot nav { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.site-foot a { color: var(--muted); }

/* -------------------------------------------------------------- 狭い画面 */

@media (max-width: 900px) {
  .panels { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { font-size: 14.5px; }
  main { padding: 0 12px 44px; }
  .hero { padding: 28px 0 20px; }
  .lab { padding: 10px; border-radius: 12px; }
  #scene { height: clamp(400px, 62vh, 540px); }
  .stage-tall #scene { height: clamp(600px, 88vh, 780px); }
  .drive { flex-direction: column; gap: 14px; }
  .lever-wrap { width: 100%; }
  .lever { display: grid; grid-template-columns: repeat(5, 1fr); gap: 4px; width: 100%; }
  .notch { min-height: 44px; font-size: 13px; }
  .gauges { grid-template-columns: repeat(auto-fill, minmax(96px, 1fr)); }
  .g-lg { grid-column: span 2; }
  .g-lg .gv b { font-size: 23px; }
  .guide-nav { flex-wrap: wrap; }
  .dots { order: 3; width: 100%; }
  .doc h2 { font-size: 18px; }
  .doc-table { display: block; overflow-x: auto; white-space: nowrap; }
  .doc-table td, .doc-table th { white-space: normal; min-width: 8.5em; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}