/* CELTIC calculator. Tokens mirror DESIGN.md. Light = paper chart; dark = night ward. */
:root {
  --paper: #FFFFFF; --paper-2: #F5F6F7; --ink: #16181D; --ink-2: #3F434C; --muted: #5E6370;
  --rule: #CBCFD6; --rule-strong: #2A2D36; --grid: #E6E8EC;
  --claret: #8C2338; --claret-ink: #6F1B2C; --claret-wash: #F6E7EA;
  --serif: "Literata", "Charter", Georgia, serif;
  --sans: "Atkinson Hyperlegible Next", Verdana, sans-serif;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --w: 880px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #15171B; --paper-2: #1D2026; --ink: #ECEEF1; --ink-2: #C9CDD5; --muted: #A3A8B3;
    --rule: #3B3F48; --rule-strong: #C9CDD5; --grid: #2A2E36;
    --claret: #E3909F; --claret-ink: #F0B2BC; --claret-wash: #3A1E25;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--sans); font-size: 0.9375rem; line-height: 1.4;
  -webkit-font-smoothing: antialiased; font-variant-numeric: tabular-nums;
}
a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 2px; }
p { margin: 0; }
h1, h2, h3 { margin: 0; font-weight: 600; }
button, input { font: inherit; color: inherit; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--paper); padding: 8px 12px; }
.skip:focus { left: 16px; z-index: 10; outline: 2px solid var(--claret); }
:focus-visible { outline: 2px solid var(--claret); outline-offset: 2px; }

/* masthead */
.masthead { max-width: var(--w); margin: 0 auto; padding: 40px 16px 0; }
h1 { font-family: var(--serif); font-size: 1.75rem; line-height: 1.15; letter-spacing: -0.005em; text-wrap: balance; }
.wordmark { color: var(--claret); }
.expand { font-weight: 400; color: var(--ink-2); font-size: 1.25rem; }
.lede { font-family: var(--serif); font-size: 1rem; line-height: 1.5; margin-top: 12px; max-width: 62ch; }
.privacy { margin-top: 12px; max-width: 70ch; color: var(--ink-2); }
.privacy strong { color: var(--ink); font-weight: 700; }

/* sheet */
.sheet { max-width: var(--w); margin: 24px auto 0; padding: 0 16px 40px; }
.tiers { border-top: 1px solid var(--rule-strong); border-bottom: 1px solid var(--rule); }
.tiers [role="tablist"] { display: flex; gap: 32px; }
.tiers [role="tab"] {
  background: none; border: 0; border-bottom: 3px solid transparent; padding: 12px 0 10px; margin-bottom: -1px;
  text-align: left; cursor: pointer; color: var(--ink-2); min-height: 44px;
}
.tiers [role="tab"]:hover { color: var(--ink); }
.tiers [role="tab"][aria-selected="true"] { color: var(--ink); border-bottom-color: var(--claret); }
.tier-name { display: block; font-weight: 700; }
.tier-meta { display: block; font-size: 0.8125rem; color: var(--muted); margin-top: 2px; }
.tiers [role="tab"][aria-selected="true"] .tier-meta { color: var(--ink-2); }
.tiers-note { font-size: 0.8125rem; color: var(--muted); padding: 8px 0 10px; }

.columns { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 40px; margin-top: 24px; align-items: start; }
.rowhead { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; font-size: 0.8125rem; font-weight: 700; letter-spacing: 0.02em; text-transform: uppercase; color: var(--ink-2); padding-bottom: 6px; border-bottom: 1px solid var(--rule-strong); }
.rowhead-meta, .rowhead-answer { font-weight: 400; text-transform: none; letter-spacing: 0; color: var(--muted); }

/* finding rows */
.row { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 8px 16px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--rule); }
.row-label { font-weight: 500; }
.row-label .num { color: var(--muted); font-weight: 400; margin-right: 6px; }
.row-hint { color: var(--muted); font-size: 0.8125rem; margin-top: 2px; max-width: 46ch; }
.row-msg { grid-column: 1 / -1; font-size: 0.8125rem; color: var(--claret-ink); }
.row.has-error .field input { border-color: var(--claret); }
.derived { grid-column: 1 / -1; font-size: 0.8125rem; color: var(--ink-2); }
.derived b { font-weight: 700; color: var(--ink); }
.seg { display: inline-flex; border: 1px solid var(--rule-strong); border-radius: 2px; overflow: hidden; }
.seg button { background: var(--paper); border: 0; padding: 0 16px; min-width: 60px; min-height: 44px; cursor: pointer; color: var(--ink-2); font-weight: 500; }
.seg button + button { border-left: 1px solid var(--rule-strong); }
.seg button:hover { background: var(--paper-2); color: var(--ink); }
.seg button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.seg button:focus-visible { outline-offset: -3px; }
.field { display: inline-flex; align-items: center; gap: 8px; }
.field input { width: 6.5rem; min-height: 44px; padding: 8px 10px; border: 1px solid var(--rule-strong); border-radius: 2px; background: var(--paper); text-align: right; font-weight: 500; }
.field input::placeholder { color: var(--muted); }
.field .unit { color: var(--muted); font-size: 0.8125rem; white-space: nowrap; }
.incomplete { margin-top: 12px; color: var(--ink-2); font-size: 0.875rem; min-height: 1.4em; }
.incomplete:empty { display: none; }

/* result column */
.result { position: sticky; top: 16px; }
.total { padding: 12px 0 14px; border-bottom: 1px solid var(--rule); }
.prob { display: flex; align-items: baseline; gap: 2px; min-height: 3rem; }
.prob-n { font-size: 3rem; font-weight: 700; line-height: 1; letter-spacing: -0.02em; transition: color 180ms var(--ease); }
.prob-unit { font-size: 1.5rem; font-weight: 700; line-height: 1; }
.band { margin-top: 6px; font-weight: 700; }
.band-note { color: var(--ink-2); font-size: 0.875rem; margin-top: 4px; }
.band-note:empty { display: none; }
.thresholds { color: var(--muted); font-size: 0.8125rem; margin-top: 10px; }
.is-rule-in .prob-n, .is-rule-in .band { color: var(--claret); }
.is-rule-out .prob-n, .is-rule-out .band { color: var(--ink); }
.is-indeterminate .prob-n, .is-indeterminate .band { color: var(--ink-2); }
.is-empty .prob-n { color: var(--muted); }
.contrib-h { margin-top: 24px; }
.contrib-lede { color: var(--muted); font-size: 0.8125rem; margin: 8px 0 4px; }
.contrib { list-style: none; margin: 0; padding: 0; }
.contrib li { display: grid; grid-template-columns: 7.5rem minmax(0, 1fr) 3.6rem; gap: 8px; align-items: center; padding: 7px 0; border-bottom: 1px solid var(--rule); font-size: 0.8125rem; }
.contrib .c-label { font-weight: 500; color: var(--ink); overflow-wrap: anywhere; }
.contrib .c-or { color: var(--muted); font-weight: 400; display: block; }
.contrib .c-val { text-align: right; font-weight: 700; }
.contrib .c-val.pos { color: var(--claret); }
.contrib .c-val.neg { color: var(--ink); }
.contrib .c-val.zero { color: var(--muted); font-weight: 500; }
.axis { position: relative; height: 22px; background: linear-gradient(to right, transparent calc(50% - 0.5px), var(--rule-strong) calc(50% - 0.5px), var(--rule-strong) calc(50% + 0.5px), transparent calc(50% + 0.5px)); }
.axis .bar { position: absolute; top: 5px; height: 12px; transform: scaleX(0); transition: transform 180ms var(--ease); }
.axis .bar.grow { transform: scaleX(1); }
.axis .bar.pos { left: 50%; background: var(--claret); transform-origin: left center; }
.axis .bar.neg { right: 50%; background: var(--ink); transform-origin: right center; }
.axis .bar.zero { left: calc(50% - 1px); width: 2px; background: var(--muted); transform: none; }
.absent { margin-top: 10px; font-size: 0.8125rem; color: var(--muted); }
.absent:empty { display: none; }
.hand { margin-top: 12px; padding-top: 10px; border-top: 1px solid var(--rule-strong); font-size: 0.875rem; color: var(--ink-2); }
.hand b { color: var(--ink); font-weight: 700; }
.hand:empty { display: none; }

/* about */
.about { max-width: var(--w); margin: 0 auto; padding: 24px 16px 8px; border-top: 1px solid var(--rule-strong); font-family: var(--serif); font-size: 1rem; line-height: 1.55; }
.about h2 { font-size: 1.375rem; margin-bottom: 8px; }
.about h3 { font-family: var(--sans); font-size: 0.8125rem; font-weight: 700; letter-spacing: 0.02em; text-transform: uppercase; color: var(--ink-2); margin: 20px 0 6px; }
.about p { max-width: 66ch; }
.about-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 0 40px; }
.math { font-family: var(--sans); font-size: 0.875rem; }
.cite { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.cite p { max-width: 66ch; }
.copy { font-family: var(--sans); background: var(--paper); border: 1px solid var(--rule-strong); border-radius: 2px; padding: 0 14px; min-height: 40px; cursor: pointer; font-weight: 500; font-size: 0.875rem; }
.copy:hover { background: var(--paper-2); }
.copied { font-family: var(--sans); font-size: 0.8125rem; color: var(--ink-2); }
.foot { max-width: var(--w); margin: 24px auto 0; padding: 12px 16px 40px; border-top: 1px solid var(--rule); font-size: 0.8125rem; color: var(--muted); }
.foot a { color: var(--ink-2); }

/* phone */
@media (max-width: 720px) {
  .masthead { padding-top: 24px; }
  h1 { font-size: 1.5rem; }
  .expand { display: block; font-size: 1rem; margin-top: 2px; }
  .columns { grid-template-columns: 1fr; gap: 24px; }
  .result { position: static; }
  .tiers [role="tablist"] { gap: 24px; }
  .row { grid-template-columns: 1fr; }
  .seg button { flex: 1; }
  .seg { width: 100%; }
  .field { width: 100%; }
  .field input { flex: 1; width: auto; }
  .about-cols { grid-template-columns: 1fr; }
  .contrib li { grid-template-columns: 6rem minmax(0, 1fr) 3.4rem; }
}
@media (prefers-reduced-motion: reduce) {
  .axis .bar, .prob-n { transition: none; }
}