/* Knitting Gauge Calculator — mobile-first, system fonts, no external assets. */
:root {
  --accent: #7e22ce;        /* plum; 6.9:1 on white */
  --accent-dark: #6b21a8;
  --accent-tint: #faf5ff;
  --accent-line: #e9d5ff;
  --text: #1f1d24;
  --muted: #57534e;         /* 7.6:1 on white */
  --border: #d6d3d1;
  --input-border: #78716c;  /* 4.7:1 on white, meets 3:1 for UI */
  --error: #b91c1c;         /* 6.4:1 on white */
  --radius: 10px;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--text);
  background: #fff;
}

.wrap { max-width: 1000px; margin: 0 auto; padding: 0 1rem; }

a { color: var(--accent); text-underline-offset: 0.15em; }
a:hover { color: var(--accent-dark); }

:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 10;
  padding: 0.5rem 1rem;
  background: #fff;
  color: var(--accent);
  font-weight: 600;
}
.skip-link:focus { left: 1rem; top: 1rem; }

/* Header */
.site-header {
  background: var(--accent-tint);
  border-bottom: 1px solid var(--accent-line);
  padding: 1.75rem 0 1.25rem;
}
h1 { font-size: clamp(1.8rem, 5vw, 2.5rem); line-height: 1.15; margin: 0 0 0.6rem; }
.lede { margin: 0 0 1rem; max-width: 70ch; }
.jump ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0.25rem 1.25rem; }
.jump a { display: inline-block; padding: 0.25rem 0; font-weight: 600; }

h2 { font-size: 1.5rem; line-height: 1.25; margin: 0 0 0.5rem; }
h3 { font-size: 1.15rem; line-height: 1.3; margin: 1.5rem 0 0.35rem; }

/* Toolbar: units + reset */
.toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.5rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
}
.units { border: 0; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 0.25rem 1.25rem; align-items: center; }
.units legend { float: left; padding: 0; margin-right: 0.75rem; font-weight: 700; }
.units label { display: inline-flex; align-items: center; gap: 0.4rem; min-height: 44px; cursor: pointer; }
input[type="radio"] { width: 1.15rem; height: 1.15rem; margin: 0; accent-color: var(--accent); }
.status { margin: 0; flex-basis: 100%; min-height: 1.6em; }
.status:empty { min-height: 0; }

.noscript { margin: 1rem 0; padding: 0.75rem 1rem; border: 2px solid var(--accent); border-radius: var(--radius); }

/* Calculator sections */
.calc { padding-top: 2rem; scroll-margin-top: 0.5rem; }
.calc + .calc { margin-top: 1rem; border-top: 1px solid var(--border); }

fieldset {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 0 0 1rem;
  padding: 0.75rem 1rem 1rem;
  min-width: 0;
}
legend { font-weight: 700; padding: 0 0.35rem; }
fieldset.nested { margin: 1rem 0 0; background: #fcfcfc; }

.grid { display: grid; gap: 0.9rem 1rem; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); max-width: 26rem; }

.field label { display: block; font-weight: 600; margin-bottom: 0.25rem; line-height: 1.35; }
.unit-note { font-weight: 400; color: var(--muted); }
.hint { margin: 0.3rem 0 0; font-size: 0.95rem; color: var(--muted); }
fieldset > .hint { margin: 0 0 0.6rem; }

input[type="number"] {
  width: 100%;
  min-height: 44px;
  padding: 0.5rem 0.65rem;
  font: inherit;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--input-border);
  border-radius: 8px;
}
input[aria-invalid="true"] { border: 2px solid var(--error); }
.field-error { margin: 0.3rem 0 0; color: var(--error); font-size: 0.95rem; font-weight: 600; }
.field-error:empty { display: none; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0.5rem 1.1rem;
  font: inherit;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  border: 2px solid var(--accent);
  border-radius: 8px;
  cursor: pointer;
}
.btn:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
.btn-secondary { color: var(--accent); background: #fff; }
.btn-secondary:hover { color: #fff; }
.btn:disabled { opacity: 0.55; cursor: not-allowed; }
.actions { margin: 1rem 0 0; }

/* Results */
.results {
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  background: var(--accent-tint);
  border: 1px solid var(--accent-line);
  border-left: 6px solid var(--accent);
  border-radius: var(--radius);
}
.results > :first-child { margin-top: 0; }
.results > :last-child { margin-bottom: 0; }
.headline { font-size: 1.25rem; line-height: 1.35; margin: 0 0 0.6rem; }
.results-sub { margin: 1.1rem 0 0.4rem; font-size: 1.05rem; }
.kv { display: grid; gap: 0.45rem; margin: 0.5rem 0; }
.kv > div { display: grid; grid-template-columns: 1fr; }
.kv dt { font-weight: 700; }
.kv dd { margin: 0; }
.options { margin: 0.4rem 0 0.75rem; padding-left: 1.25rem; }
.options li { margin: 0.25rem 0; }
.tag {
  display: inline-block;
  margin-left: 0.35rem;
  padding: 0 0.5rem;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: #fff;
  background: var(--accent);
  border-radius: 999px;
}
.note, .muted { color: var(--muted); font-size: 0.95rem; }

/* Article content */
.content { max-width: 72ch; padding: 2.5rem 0 1rem; }
.content h2 { margin-top: 2.25rem; scroll-margin-top: 0.5rem; }
.content h2:first-child { margin-top: 0; }
.content li { margin: 0.35rem 0; }

.site-footer {
  margin-top: 2rem;
  padding: 1.25rem 0 2rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.95rem;
}
.site-footer p { margin: 0.25rem 0; }

@media (min-width: 640px) {
  .wrap { padding: 0 1.5rem; }
  .kv > div { grid-template-columns: minmax(11rem, 15rem) 1fr; gap: 1rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

@media print {
  @page { margin: 1.5cm; }
  body { font-size: 11pt; }
  .skip-link, .jump, .toolbar, .btn, .actions, .content, .noscript, .status { display: none !important; }
  .site-header { background: none; border: 0; padding: 0 0 0.5rem; }
  .lede { display: none; }
  .calc { padding-top: 1rem; break-inside: avoid; }
  .results { background: none; border: 1px solid #000; border-left-width: 4px; break-inside: avoid; }
  .tag { color: #000; background: none; border: 1px solid #000; }
  a { color: inherit; }
}