:root {
  color-scheme: light;
  --paper: #f4efe6;
  --card: #fffdf8;
  --ink: #293437;
  --muted: #59676a;
  --line: #d7cfc2;
  --red: #a7332b;
  --blue: #285d73;
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 17px/1.8 system-ui, -apple-system, "Hiragino Kaku Gothic ProN", Meiryo, sans-serif; }
a { color: var(--blue); text-underline-offset: 3px; }
.page { width: min(100% - 32px, 820px); margin: 0 auto; padding: 28px 0 56px; }
.crumbs { margin: 0 0 24px; color: var(--muted); font-size: .84rem; }
.crumbs a { color: var(--red); }
.masthead { margin-bottom: 20px; padding: 22px 26px 24px; border-top: 4px solid var(--red); background: var(--card); }
.kicker { margin: 0 0 8px; color: var(--red); font-size: .75rem; font-weight: 800; letter-spacing: .12em; }
h1, h2, h3 { line-height: 1.4; }
h1 { margin: 0; font-family: Georgia, "Yu Mincho", "Hiragino Mincho ProN", serif; font-size: clamp(1.8rem, 6vw, 2.6rem); }
.dek { max-width: 65ch; margin: 12px 0 0; color: var(--muted); }
main { padding: 8px 4px; }
h2 { margin: 2.1em 0 .5em; padding-bottom: .25em; border-bottom: 1px solid var(--line); font-family: Georgia, "Yu Mincho", "Hiragino Mincho ProN", serif; font-size: 1.45rem; }
h3 { margin: 1.4em 0 .4em; font-size: 1.08rem; }
p { margin: .7em 0; }
ul, ol { padding-left: 1.5em; }
li + li { margin-top: .3em; }
.note, .result, .caution { margin: 1.2em 0; padding: 14px 17px; background: var(--card); }
.note { border-left: 3px solid var(--blue); }
.result { border-left: 3px solid var(--red); }
.caution { border: 1px solid var(--line); color: var(--muted); }
.formula { overflow-wrap: anywhere; padding: 12px 14px; background: #ebe5da; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .92rem; }
.table-wrap { overflow-x: auto; margin: 1em 0; }
table { width: 100%; border-collapse: collapse; background: var(--card); font-size: .94rem; }
th, td { padding: 10px 12px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: #ebe5da; }
.steps { counter-reset: steps; list-style: none; padding: 0; }
.steps li { position: relative; min-height: 2.4em; margin: 12px 0; padding: 10px 14px 10px 52px; background: var(--card); counter-increment: steps; }
.steps li::before { position: absolute; left: 14px; color: var(--red); content: counter(steps, decimal-leading-zero); font-weight: 800; }
.tool-link { display: inline-block; min-height: 44px; margin: 12px 0; padding: 9px 18px; border-radius: 999px; background: var(--red); color: white; font-weight: 800; text-decoration: none; }
.related { margin-top: 28px; padding-top: 16px; border-top: 1px solid var(--line); }
.related a { display: block; padding: 5px 0; }
.site-foot { margin-top: 30px; padding-top: 14px; border-top: 1px solid var(--line); color: var(--muted); font-size: .83rem; }
.cards { display: grid; gap: 14px; margin-top: 20px; }
.card { display: block; padding: 17px 19px; border: 1px solid var(--line); background: var(--card); color: var(--ink); text-decoration: none; }
.card:hover, .card:focus-visible { border-color: var(--red); }
.card strong { display: block; color: var(--red); font-size: 1.1rem; }
.card span { display: block; margin-top: 4px; color: var(--muted); }
@media (max-width: 520px) { body { font-size: 16px; } .page { width: min(100% - 24px, 820px); padding-top: 14px; } .masthead { padding: 18px 17px 20px; } th, td { padding: 8px; } }