/* ---- style.css */
:root {
  --bg: #f6f7f5; --card: #ffffff; --ink: #14201d; --muted: #5b6965; --line: #dfe4e1;
  --accent: #0b7a6b; --accent-ink: #ffffff; --accent-soft: #e3f3ef; --warn-bg: #fff4dc; --warn-ink: #6b4a00;
  --fill: #5dbfae; --edge: #7d8a86; --radius: 14px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1514; --card: #172120; --ink: #e8efec; --muted: #9aaba6; --line: #2a3836;
    --accent: #4fc7b3; --accent-ink: #06231f; --accent-soft: #17332f; --warn-bg: #3a2d0c; --warn-ink: #ffdf9a;
    --fill: #2f8f80; --edge: #6b7d78;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
.skip { position: absolute; left: 8px; top: -60px; z-index: 10; background: var(--card); color: var(--ink); padding: 10px 14px; border-radius: 10px; border: 1px solid var(--edge); font-weight: 600; }
.skip:focus { top: 8px; }
main:focus { outline: none; }
.wrap { max-width: 880px; margin: 0 auto; padding: 0 16px; }
header.site { border-bottom: 1px solid var(--line); background: var(--card); }
header.site .wrap { display: flex; align-items: center; gap: 0 20px; min-height: 56px; flex-wrap: wrap; padding-top: 6px; padding-bottom: 6px; }
header.site .brand { font-weight: 700; color: var(--ink); text-decoration: none; letter-spacing: -0.01em; }
header.site .brand { padding: 8px 0; }
header.site nav { display: flex; flex-wrap: wrap; gap: 0 18px; margin-left: auto; font-size: 15px; }
header.site nav a { color: var(--muted); text-decoration: none; padding: 8px 0; white-space: nowrap; }
header.site nav a:hover { color: var(--accent); }
header.site nav a[aria-current] { color: var(--ink); font-weight: 600; }
@media (max-width: 640px) {
  header.site nav { margin-left: 0; width: 100%; gap: 0 16px; font-size: 14px; }
  header.site nav a { padding: 6px 0; }
}
@media (max-width: 420px) { header.site nav a.opt { display: none; } }
main { padding: 28px 0 56px; }
h1 { font-size: clamp(1.7rem, 4.5vw, 2.4rem); line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 8px; text-wrap: balance; }
h2 { font-size: 1.3rem; letter-spacing: -0.01em; margin: 40px 0 10px; }
h3 { font-size: 1.05rem; margin: 22px 0 4px; }
p { margin: 0 0 12px; }
.lede { color: var(--muted); font-size: 1.08rem; max-width: 62ch; margin-bottom: 22px; }
.crumbs { font-size: 14px; color: var(--muted); margin-bottom: 10px; }
.crumbs ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0 6px; }
.crumbs li + li::before { content: "›"; margin-right: 6px; }
.crumbs a { color: var(--muted); }
.reviewed { font-size: 14px; color: var(--muted); margin-top: 28px; }
main ul, main ol { padding-left: 1.2em; margin: 0 0 12px; }
main li { margin-bottom: 4px; }

.calc {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  display: grid; grid-template-columns: 1fr 1fr; overflow: hidden;
}
.calc .in { padding: 20px; display: grid; gap: 16px; align-content: start; }
.calc .res { padding: 20px; background: var(--accent-soft); display: flex; flex-direction: column; gap: 6px; }
@media (max-width: 700px) { .calc { grid-template-columns: 1fr; } }
.modes { display: flex; background: var(--bg); border-radius: 10px; padding: 3px; gap: 3px; }
.modes button {
  flex: 1; border: 0; background: none; color: var(--muted); font: inherit; font-size: 14px; font-weight: 600;
  padding: 7px 8px; border-radius: 8px; cursor: pointer;
}
.modes button[aria-pressed="true"] { background: var(--card); color: var(--ink); box-shadow: 0 1px 2px rgba(0,0,0,.12); }
.field label, .field .label { display: block; font-weight: 600; font-size: 14px; margin-bottom: 5px; }
.field .ctl { display: flex; gap: 8px; align-items: stretch; }
.field .ctl .u { align-self: center; color: var(--muted); font-size: 15px; min-width: 2.2em; }
input[type="number"], select {
  font: inherit; color: var(--ink); background: var(--bg); border: 1px solid var(--edge);
  border-radius: 10px; padding: 9px 12px; width: 100%; min-width: 0; height: 44px;
}
select { width: auto; }
.field select.full { width: 100%; }
input:focus-visible, select:focus-visible, button:focus-visible, a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 7px; }
.chips button {
  font: inherit; font-size: 13px; padding: 4px 10px; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--edge); background: none; color: var(--muted); min-height: 28px;
}
.chips button:hover { border-color: var(--accent); color: var(--accent); }
.pair { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.pair label { color: var(--muted); font-size: 12px; font-weight: 400; margin-bottom: 3px; }

.big { display: flex; align-items: baseline; flex-wrap: wrap; gap: 0 10px; margin-bottom: 8px; }
.big .lbl { width: 100%; font-size: 14px; font-weight: 600; color: var(--muted); }
.big .val { font-size: 3.2rem; font-weight: 750; line-height: 1.05; letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.big .suf { font-size: 1.1rem; font-weight: 600; }
.row { display: flex; justify-content: space-between; gap: 12px; font-size: 15px; padding: 5px 0; border-top: 1px solid color-mix(in srgb, var(--ink) 12%, transparent); }
.row span { color: var(--muted); }
.row b { font-variant-numeric: tabular-nums; text-align: right; }
.hint { color: var(--muted); margin: 6px 0; }
.warn { background: var(--warn-bg); color: var(--warn-ink); border-radius: 10px; padding: 9px 12px; font-size: 14px; margin: 10px 0 0; }
.viz { margin-top: auto; padding-top: 14px; }
.viz svg { width: 100%; height: auto; display: block; }
.viz .barrel { fill: var(--card); stroke: var(--ink); stroke-width: 1.5; }
.viz .fill { fill: var(--fill); }
.viz .plunger { fill: var(--ink); }
.viz .needle, .viz .rod { fill: var(--muted); }
.viz .flange { fill: var(--ink); }
.viz .tick { stroke: var(--ink); stroke-width: 1; }
.viz .tl { font-size: 11px; fill: var(--muted); text-anchor: middle; }
.viz .mark { font-size: 13px; font-weight: 700; fill: var(--ink); text-anchor: middle; }
.fine { font-size: 13px; color: var(--muted); margin-top: 10px; }

.status { border-left: 3px solid var(--accent); padding: 2px 0 2px 12px; color: var(--muted); font-size: 15px; margin: 0 0 22px; }
.tablewrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); }
table { border-collapse: collapse; width: 100%; font-size: 15px; font-variant-numeric: tabular-nums; }
th, td { padding: 9px 14px; text-align: right; border-bottom: 1px solid var(--line); white-space: nowrap; }
th:first-child, td:first-child { text-align: left; }
thead th { font-size: 13px; color: var(--muted); font-weight: 600; background: var(--bg); }
tbody tr:last-child td { border-bottom: 0; }
td small { color: var(--muted); }
main .grid li, main .links li { margin: 0; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 10px; padding: 0; margin: 0; list-style: none; }
.grid a {
  display: block; padding: 12px 14px; background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; text-decoration: none; color: var(--ink); font-weight: 600;
}
.grid a:hover { border-color: var(--accent); }
.grid a small { display: block; font-weight: 400; color: var(--muted); }
.links { display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 0; list-style: none; }
.links a { display: inline-block; padding: 5px 12px; border: 1px solid var(--line); border-radius: 999px; background: var(--card); text-decoration: none; font-size: 14px; }
ol.steps { padding-left: 1.2em; }
ol.steps li { margin-bottom: 6px; }
.formula { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 14px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; overflow-x: auto; white-space: pre; }
.partner {
  margin-top: 22px; padding: 16px 18px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--card);
  display: flex; gap: 16px; align-items: center; flex-wrap: wrap;
}
.partner div { flex: 1 1 280px; }
.partner .tag { font-size: 11px; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.partner p { margin: 2px 0 0; font-size: 15px; color: var(--muted); }
.partner a.btn { background: var(--accent); color: var(--accent-ink); text-decoration: none; font-weight: 650; padding: 10px 16px; border-radius: 10px; white-space: nowrap; }
footer.site { border-top: 1px solid var(--line); padding: 24px 0 40px; font-size: 13px; color: var(--muted); }
footer.site p { max-width: 75ch; }
footer.site nav { margin-bottom: 12px; }
footer.site nav ul { list-style: none; margin: 0 0 4px; padding: 0; display: flex; gap: 0 16px; flex-wrap: wrap; }
footer.site nav a { display: inline-block; padding: 5px 0; }
footer.site a { color: var(--muted); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
}

/* Print: the entered values and the result, in black on white, nothing else from the calculator chrome. */
@media print {
  :root {
    --bg: #fff; --card: #fff; --ink: #000; --muted: #333; --line: #999; --edge: #666;
    --accent: #000; --accent-soft: #fff; --warn-bg: #fff; --warn-ink: #000; --fill: #bbb;
    color-scheme: light;
  }
  body { font-size: 11pt; }
  *:focus, *:focus-visible { outline: none !important; }
  input[type="number"] { -moz-appearance: textfield; appearance: textfield; }
  input::-webkit-outer-spin-button, input::-webkit-inner-spin-button { -webkit-appearance: none; }
  .skip, header.site nav, footer.site nav, .crumbs, .chips, .modes, .partner { display: none !important; }
  header.site { border: 0; }
  header.site .wrap { min-height: 0; }
  main { padding: 8pt 0 0; }
  .wrap { max-width: none; padding: 0; }
  a { color: inherit; text-decoration: none; }
  .calc { display: block; border: 1pt solid #000; break-inside: avoid; }
  .calc .in { gap: 8pt; padding: 12pt; }
  .calc .res { border-top: 1pt solid #000; padding: 12pt; }
  .calc select { appearance: none; -webkit-appearance: none; }
  .warn { border: 1pt solid #000; }
  .big .val { font-size: 28pt; }
  .viz svg { max-width: 420pt; }
  .tablewrap { overflow: visible; border-color: #999; }
  th, td { white-space: normal; padding: 4pt 8pt; }
  h2, h3 { break-after: avoid; }
  table, .formula, .calc { break-inside: avoid; }
  .formula { white-space: pre-wrap; }
  footer.site { padding: 12pt 0 0; }
}

/* ---- tools.css */
/* Extras for the /tools/ pages. Everything else reuses style.css. */
.calc[data-tool] + h2, .calc[data-tool] + h3 { margin-top: 32px; }
.calc input[type="text"] {
  font: inherit; color: var(--ink); background: var(--bg); border: 1px solid var(--line);
  border-radius: 10px; padding: 9px 12px; width: 100%; min-width: 0; height: 44px;
}
.calc .field .ctl select { flex: none; }
.big.sm { margin-bottom: 4px; }
.big.sm .val { font-size: 2rem; }
.big .val { overflow-wrap: anywhere; }
.charts { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; align-items: start; }
.charts h3 { margin-top: 0; }
.formula + p, .formula + .tablewrap, .tablewrap + p, .calc[data-tool] + .formula { margin-top: 12px; }