:root {
  --bg: #f6f7f9; --card: #fff; --text: #1b1f24; --muted: #59626e; --line: #d9dee5;
  --accent: #b45309; --accent-ink: #fff; --a: #2563eb; --b: #c2410c; --up: #166534; --down: #9f1239;
  --radius: 10px; color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #111418; --card: #1a1f25; --text: #e8ebef; --muted: #a2abb6; --line: #2e3640;
    --accent: #f59e0b; --accent-ink: #111; --a: #60a5fa; --b: #fb923c; --up: #4ade80; --down: #fb7185; }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; background: var(--bg); color: var(--text); }
a { color: var(--accent); }
a:focus-visible, button:focus-visible, input:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.wrap { max-width: 860px; margin: 0 auto; padding: 0 16px; }
.skip { position: absolute; left: -999px; } .skip:focus { left: 8px; top: 8px; background: var(--card); padding: 8px; z-index: 9; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
header.site { border-bottom: 1px solid var(--line); background: var(--card); }
header.site .wrap { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px; padding-top: 10px; padding-bottom: 10px; }
.brand { font-weight: 700; color: var(--text); text-decoration: none; font-size: 1.1rem; }
nav a { margin-left: 14px; color: var(--muted); text-decoration: none; } nav a:hover { color: var(--text); text-decoration: underline; }
nav a[aria-current] { color: var(--text); font-weight: 600; }
main { padding: 20px 0 32px; }
h1 { font-size: 1.6rem; line-height: 1.25; margin: 0 0 6px; }
h2 { font-size: 1.2rem; margin: 0 0 10px; }
.lead { color: var(--muted); margin: 0 0 18px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; margin-bottom: 16px; }
.inputs { display: grid; grid-template-columns: 1fr; gap: 12px; }
@media (min-width: 620px) { .inputs { grid-template-columns: 1fr auto 1fr; align-items: start; } }
label { display: block; font-weight: 600; margin-bottom: 4px; }
label .tag { display: inline-block; width: 1.4em; text-align: center; border-radius: 4px; color: #fff; margin-right: 6px; }
.tag-a { background: var(--a); } .tag-b { background: var(--b); }
input[type=text] { width: 100%; font: inherit; font-size: 1.15rem; padding: 10px 12px; border: 2px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--text); }
input[aria-invalid=true] { border-color: var(--down); }
.msg { min-height: 1.3em; font-size: .85rem; color: var(--muted); margin: 4px 0 0; }
button { font: inherit; cursor: pointer; border: 1px solid var(--line); background: var(--bg); color: var(--text); border-radius: 8px; padding: 8px 12px; }
button.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
#swap { align-self: center; margin-top: 8px; }
.examples { margin: 10px 0 0; font-size: .9rem; color: var(--muted); }
.examples button { padding: 3px 8px; font-size: .85rem; margin: 2px; }
.summary { margin: 0 0 12px; } .summary:empty { display: none; }
.warn { color: var(--down); }
.table-scroll { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-variant-numeric: tabular-nums; }
th, td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); vertical-align: top; }
thead th { font-size: .85rem; color: var(--muted); }
.lbl { display: block; color: var(--text); font-weight: 700; font-size: .95rem; }
td span { display: block; } .v-mm, .v-pct { color: var(--muted); font-size: .85rem; }
td.up { color: var(--up); } td.down { color: var(--down); }
caption { text-align: left; font-weight: 600; padding-bottom: 6px; }
.hint { color: var(--muted); margin: 0; }
svg.profile { width: 100%; height: auto; max-height: 300px; display: block; }
svg.profile .side, svg.profile .tread { fill: none; stroke-width: 3; }
svg.profile .tire-a { stroke: var(--a); } svg.profile .tire-b { stroke: var(--b); stroke-dasharray: 7 4; }
svg.profile .tread.tire-a { fill: color-mix(in srgb, var(--a) 15%, transparent); }
svg.profile .tread.tire-b { fill: color-mix(in srgb, var(--b) 15%, transparent); }
svg.profile .rim { fill: none; stroke-width: 1.5; opacity: .6; }
svg.profile .ground { stroke: var(--muted); stroke-width: 1; }
svg.profile text { fill: var(--muted); font-size: 12px; font-family: inherit; }
.legend { font-size: .85rem; color: var(--muted); margin: 6px 0 0; }
.pairs { columns: 2 220px; padding-left: 18px; margin: 0; }
.prose p, .prose li { max-width: 68ch; }
code { background: var(--bg); padding: 1px 5px; border-radius: 4px; border: 1px solid var(--line); }
footer.site { border-top: 1px solid var(--line); padding: 20px 0 28px; color: var(--muted); font-size: .95rem; text-align: center; }
@media (max-width: 560px) {
  table { font-size: .82rem; } th, td { padding: 6px 3px; }
  .v-mm, .v-pct { font-size: .72rem; } .lbl { font-size: .8rem; }
  .results th[scope=row] { width: 26%; } #swap { width: 100%; margin: 0; }
  nav a { margin-left: 10px; }
}