:root {
  --bg: #f3f5f8;
  --surface: #ffffff;
  --ink: #16202a;
  --muted: #566472;
  --line: #d9e0e8;
  --dark: #18232e;
  --dark-ink: #dbe4ec;
  --brand: #e07b22;
  --link: #a14a0c;
  --brand-soft: #fdf1e5;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16.5px/1.65 var(--sans); }
a { color: var(--link); text-underline-offset: .18em; }
a:hover { color: #6f3108; }
:focus-visible { outline: 3px solid var(--brand); outline-offset: 2px; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 12px; z-index: 10; background: var(--surface); padding: 8px 14px; }

header.site { background: var(--dark); }
.bar { max-width: 78rem; margin: 0 auto; padding: 14px 20px; }
.brand { display: inline-flex; align-items: center; gap: 12px; color: #fff; text-decoration: none; font-weight: 800; font-size: 1.15rem; line-height: 1.25; }
.brand svg { width: 38px; height: 38px; flex: none; }
.brand small { display: block; font-weight: 500; font-size: .78rem; color: #9fb1c1; letter-spacing: .02em; }

.layout { max-width: 78rem; margin: 0 auto; padding: 28px 20px 60px; display: grid; grid-template-columns: 240px minmax(0, 1fr); gap: 36px; align-items: start; }
nav.toc { position: sticky; top: 18px; }
.toc-title { font: 600 .75rem var(--mono); text-transform: uppercase; letter-spacing: .1em; color: var(--muted); margin: 6px 12px 8px; }
nav.toc ol { list-style: none; margin: 0; padding: 0; }
nav.toc a { display: flex; gap: 10px; align-items: baseline; padding: 9px 12px; border-radius: 8px; color: var(--ink); text-decoration: none; font-size: .95rem; }
nav.toc a .n { font: 600 .78rem var(--mono); color: var(--muted); }
nav.toc a:hover { background: #e7ecf2; }
nav.toc a[aria-current="page"] { background: var(--surface); box-shadow: inset 3px 0 0 var(--brand); font-weight: 650; }
nav.toc a[aria-current="page"] .n { color: var(--link); }

main { min-width: 0; }
article { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 32px 38px 36px; }
.crumbs { font-size: .84rem; color: var(--muted); margin-bottom: 14px; }
.crumbs a { color: var(--muted); }
h1 { font-size: clamp(1.7rem, 3.6vw, 2.3rem); line-height: 1.18; letter-spacing: -.01em; margin: 0 0 14px; }
h2 { font-size: 1.36rem; line-height: 1.25; margin: 38px 0 12px; padding-bottom: 6px; border-bottom: 2px solid var(--line); }
h3 { font-size: 1.08rem; margin: 26px 0 8px; }
.lead { font-size: 1.1rem; color: #2a3846; margin: 0 0 10px; }
.meta { font: .8rem var(--mono); color: var(--muted); margin: 0 0 6px; }
p, ul, ol { margin: 0 0 15px; }
ul, ol { padding-left: 1.3em; }
li { margin-bottom: 6px; }

.cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin: 16px 0 6px; }
.card { border: 1px solid var(--line); border-radius: 10px; padding: 16px 18px; background: #fafbfc; }
.card h3 { margin: 0 0 6px; font-size: 1.02rem; }
.card p { margin: 0 0 8px; font-size: .95rem; }

ol.steps { list-style: none; padding: 0; counter-reset: step; }
ol.steps li { counter-increment: step; position: relative; padding: 2px 0 8px 54px; margin-bottom: 10px; }
ol.steps li::before { content: counter(step, decimal-leading-zero); position: absolute; left: 0; top: 2px; font: 700 .82rem var(--mono); color: #fff; background: var(--dark); border-radius: 6px; padding: 4px 8px; }

.table-wrap { overflow-x: auto; margin: 16px 0 12px; border: 1px solid var(--line); border-radius: 10px; }
table { border-collapse: collapse; width: 100%; font-size: .92rem; }
th, td { padding: 9px 13px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
th { background: #edf1f5; font-weight: 600; }
tr:last-child td { border-bottom: 0; }
.num { font-family: var(--mono); white-space: nowrap; }
.source { font-size: .84rem; color: var(--muted); }
.callout { border-left: 4px solid var(--brand); background: var(--brand-soft); padding: 12px 16px; border-radius: 0 8px 8px 0; margin: 18px 0; }
.callout p:last-child { margin-bottom: 0; }

.defect { border: 1px solid var(--line); border-radius: 10px; padding: 2px 18px 12px; margin: 14px 0; }
.defect h3 { margin-top: 14px; }
.defect dl { display: grid; grid-template-columns: 130px minmax(0, 1fr); gap: 6px 14px; margin: 0; }
.defect dt { font-weight: 600; color: var(--muted); font-size: .9rem; }
.defect dd { margin: 0; }

figure { margin: 24px 0; }
figure svg { display: block; width: 100%; max-width: 440px; height: auto; margin: 0 auto; }
figcaption { font-size: .84rem; color: var(--muted); text-align: center; margin-top: 8px; }
.d-band { fill: #fbd9b6; }
.d-mark { stroke: var(--dark); stroke-width: 3.5; stroke-linecap: round; }
.d-axis { stroke: #9aa8b5; stroke-width: 1; }
.d-max { stroke: #b4330b; stroke-width: 1.5; stroke-dasharray: 4 4; }
.d-t { font: 600 13px var(--sans); fill: var(--ink); }
.d-v { font: 600 13px var(--mono); fill: var(--ink); }
.d-s { font: 11px var(--mono); fill: var(--muted); }
.d-maxt { font: 600 11px var(--mono); fill: #b4330b; }

.faq details { border: 1px solid var(--line); border-radius: 10px; margin: 0 0 10px; padding: 0 16px; background: #fbfcfd; }
.faq summary { cursor: pointer; font-weight: 650; padding: 13px 26px 13px 0; list-style: none; position: relative; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "▸"; position: absolute; right: 2px; top: 12px; color: var(--link); transition: transform .15s; }
.faq details[open] summary::after { transform: rotate(90deg); }
.faq .answer { padding: 0 0 4px; }

.cta { margin-top: 42px; border-radius: 12px; background: var(--dark); color: var(--dark-ink); padding: 22px 24px; }
.cta-title { color: #fff; font-weight: 750; font-size: 1.15rem; margin: 0 0 6px; }
.cta p { margin: 0 0 14px; }
.cta .btn { display: inline-block; background: var(--brand); color: #1d1206; font-weight: 750; text-decoration: none; padding: 10px 18px; border-radius: 8px; }
.cta .btn:hover { background: #f29747; color: #1d1206; }

footer.site { background: var(--dark); color: #9fb1c1; font-size: .86rem; }
footer.site .bar { padding-top: 22px; padding-bottom: 26px; }
footer.site p { margin: 0 0 8px; max-width: 52rem; }
footer.site a { color: #c9d6e2; }

@media (max-width: 900px) {
  .layout { grid-template-columns: minmax(0, 1fr); gap: 16px; padding-top: 18px; }
  nav.toc { position: static; }
  .toc-title { display: none; }
  nav.toc ol { display: flex; flex-wrap: wrap; gap: 6px; }
  nav.toc a { padding: 6px 10px; border: 1px solid var(--line); background: var(--surface); font-size: .88rem; }
  article { padding: 24px 20px 28px; }
  .cards { grid-template-columns: 1fr; }
}
@media (max-width: 520px) {
  .defect dl { grid-template-columns: 1fr; gap: 2px; }
  .defect dd { margin-bottom: 8px; }
}