/* Site styles. Chart tokens follow a validated categorical palette (light + dark). */
:root {
  color-scheme: light;
  --page: #f9f9f7;
  --surface: #fcfcfb;
  --ink: #0b0b0b;
  --ink-2: #52514e;
  --ink-3: #898781;
  --grid: #e1e0d9;
  --axis: #c3c2b7;
  --border: rgba(11, 11, 11, 0.10);
  --accent: #256abf;
  --accent-ink: #ffffff;
  --good: #006300;
  --series-1: #2a78d6;
  --series-2: #eb6834;
  --series-3: #1baf7a;
  --hover: rgba(11, 11, 11, 0.05);
  --shadow: 0 1px 2px rgba(11, 11, 11, 0.06);
}
@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --page: #0d0d0d;
    --surface: #1a1a19;
    --ink: #ffffff;
    --ink-2: #c3c2b7;
    --ink-3: #898781;
    --grid: #2c2c2a;
    --axis: #383835;
    --border: rgba(255, 255, 255, 0.10);
    --accent: #3987e5;
    --accent-ink: #0b0b0b;
    --good: #0ca30c;
    --series-1: #3987e5;
    --series-2: #d95926;
    --series-3: #199e70;
    --hover: rgba(255, 255, 255, 0.07);
    --shadow: none;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }
h1, h2, h3 { line-height: 1.25; margin: 0 0 .5em; }
h1 { font-size: clamp(1.7rem, 4vw, 2.4rem); letter-spacing: -0.01em; }
h2 { font-size: 1.35rem; margin-top: 2em; }
h3 { font-size: 1.1rem; margin-top: 1.5em; }
p, ul, ol { margin: 0 0 1em; }
li { margin-bottom: .35em; }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 16px; }
.narrow { max-width: 740px; }

/* Header / footer */
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding-top: 14px; padding-bottom: 14px; }
.brand { font-weight: 700; font-size: 1.15rem; color: var(--ink); text-decoration: none; letter-spacing: -0.01em; }
.brand span { color: var(--accent); }
.nav { display: flex; gap: 4px 18px; flex-wrap: wrap; }
.nav a { color: var(--ink-2); text-decoration: none; font-size: .95rem; padding: 4px 0; }
.nav a:hover, .nav a[aria-current="page"] { color: var(--ink); text-decoration: underline; text-underline-offset: 6px; }
.site-footer { margin-top: 64px; padding: 28px 0 40px; border-top: 1px solid var(--border); color: var(--ink-2); font-size: .9rem; }
.site-footer nav { display: flex; gap: 6px 18px; flex-wrap: wrap; margin-bottom: 12px; }
.site-footer a { color: var(--ink-2); }
.site-footer p { margin: 0 0 .5em; max-width: 720px; }

main { padding: 28px 0 0; }
.crumbs { font-size: .875rem; color: var(--ink-3); margin-bottom: 8px; }
.crumbs a { color: var(--ink-3); }
.lede { color: var(--ink-2); font-size: 1.1rem; max-width: 680px; }

/* Home */
.hero { padding: 24px 0 8px; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; margin: 24px 0; padding: 0; list-style: none; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 18px; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 6px; }
.card h3 { margin: 0; font-size: 1.05rem; }
.card p { margin: 0; color: var(--ink-2); font-size: .95rem; }
.card a.stretch { color: var(--ink); text-decoration: none; }
.card a.stretch::after { content: ""; position: absolute; inset: 0; }
.card { position: relative; }
.card:hover { border-color: var(--accent); }
.card .go { margin-top: auto; padding-top: 6px; color: var(--accent); font-size: .9rem; font-weight: 600; }

/* Calculator layout */
.calc { display: grid; grid-template-columns: minmax(0, 340px) minmax(0, 1fr); gap: 20px; align-items: start; margin: 20px 0 8px; }
@media (max-width: 820px) { .calc { grid-template-columns: 1fr; } }
.panel { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 18px; box-shadow: var(--shadow); }
.panel h2 { margin: 0 0 12px; font-size: 1.05rem; }
.field { margin-bottom: 14px; }
.field label, .field .lbl { display: block; font-size: .9rem; font-weight: 600; margin-bottom: 4px; }
.field .hint { display: block; font-size: .8rem; color: var(--ink-3); font-weight: 400; margin-top: 2px; }
.input { position: relative; }
.input input, .input select, .field select {
  width: 100%; font: inherit; color: var(--ink); background: var(--page);
  border: 1px solid var(--axis); border-radius: 8px; padding: 9px 10px;
}
.input input:focus, .input select:focus, .field select:focus, button:focus-visible, summary:focus-visible, .chart rect:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 1px;
}
.input.pre input { padding-left: 24px; }
.input.suf input { padding-right: 30px; }
.input .affix { position: absolute; top: 50%; transform: translateY(-50%); color: var(--ink-3); font-size: .95rem; pointer-events: none; }
.input.pre .affix { left: 10px; }
.input.suf .affix { right: 10px; }
.row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
button, .btn {
  font: inherit; font-weight: 600; cursor: pointer; border-radius: 8px; padding: 8px 14px;
  background: var(--surface); color: var(--ink); border: 1px solid var(--axis);
}
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
button.small { padding: 4px 10px; font-size: .85rem; }

/* Results */
.hero-figure { font-size: clamp(2.4rem, 7vw, 3.4rem); font-weight: 700; line-height: 1.1; letter-spacing: -0.02em; margin: 2px 0 2px; }
.hero-label { color: var(--ink-2); font-size: .95rem; margin: 0; }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; margin: 16px 0 4px; }
.stat { border-top: 1px solid var(--border); padding-top: 8px; }
.stat .v { font-size: 1.3rem; font-weight: 650; line-height: 1.2; }
.stat .k { font-size: .85rem; color: var(--ink-2); }
.note { color: var(--ink-2); font-size: .9rem; margin: 12px 0 0; }
.warn { border: 1px solid var(--series-2); border-left-width: 4px; border-radius: 8px; padding: 8px 12px; font-size: .9rem; margin: 12px 0 0; background: var(--page); }
.chart-title { font-size: .95rem; font-weight: 600; margin: 20px 0 6px; }

/* Charts */
.chart { position: relative; margin-top: 4px; }
.chart svg { width: 100%; height: auto; display: block; overflow: visible; }
.chart .grid { stroke: var(--grid); stroke-width: 1; }
.chart .axis { stroke: var(--axis); stroke-width: 1; }
.chart .tick { fill: var(--ink-3); font-size: 11.5px; font-family: inherit; }
.chart .hover-band { fill: var(--hover); pointer-events: none; }
.chart .crosshair { stroke: var(--ink-3); stroke-width: 1; pointer-events: none; }
.chart .dot { stroke: var(--surface); stroke-width: 2; pointer-events: none; }
.legend { display: flex; gap: 6px 18px; flex-wrap: wrap; font-size: .875rem; color: var(--ink-2); margin-bottom: 4px; }
.legend-item { display: inline-flex; align-items: center; gap: 6px; }
.key { display: inline-block; width: 10px; height: 10px; border-radius: 3px; flex: none; }
.tip {
  position: absolute; z-index: 5; pointer-events: none; min-width: 170px;
  background: var(--surface); color: var(--ink); border: 1px solid var(--axis); border-radius: 8px;
  padding: 8px 10px; font-size: .85rem; box-shadow: 0 4px 14px rgba(0, 0, 0, .15);
}
.tip[hidden] { display: none; }
.tip strong { display: block; margin-bottom: 4px; }
.tip-row { display: flex; align-items: center; gap: 6px; color: var(--ink-2); }
.tip-row .tip-val { margin-left: auto; padding-left: 14px; color: var(--ink); font-weight: 600; font-variant-numeric: tabular-nums; }
.tip-total { border-top: 1px solid var(--border); margin-top: 4px; padding-top: 4px; }
.tip-total::before { content: ""; width: 10px; }
.splitbar { display: flex; gap: 2px; height: 22px; }
.splitbar span { min-width: 4px; }
.splitbar span:first-child { border-radius: 4px 0 0 4px; }
.splitbar span:last-child { border-radius: 0 4px 4px 0; }
.splitbar span:only-child { border-radius: 4px; }
.table-view { margin-top: 10px; font-size: .9rem; }
.table-view summary { cursor: pointer; color: var(--accent); font-weight: 600; }
.table-scroll { max-height: 320px; overflow: auto; margin-top: 8px; border: 1px solid var(--border); border-radius: 8px; }
table { border-collapse: collapse; width: 100%; }
th, td { padding: 6px 10px; text-align: left; border-bottom: 1px solid var(--grid); }
th { position: sticky; top: 0; background: var(--surface); font-size: .8rem; color: var(--ink-2); }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
tbody tr:last-child td { border-bottom: 0; }

/* Debt list */
.debt { border: 1px solid var(--border); border-radius: 10px; padding: 12px; margin-bottom: 12px; background: var(--page); }
.debt-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; gap: 8px; }
.debt-head input { font: inherit; font-weight: 600; background: transparent; border: 0; border-bottom: 1px dashed var(--axis); color: var(--ink); width: 60%; padding: 2px 0; }
.debt .row3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; align-items: end; }
.debt .row3 > div { min-width: 0; }
.debt .row3 label { display: block; font-size: .75rem; font-weight: 600; margin-bottom: 2px; }
.debt .row3 input { width: 100%; min-width: 0; font: inherit; color: var(--ink); background: var(--surface); border: 1px solid var(--axis); border-radius: 8px; padding: 7px 8px; }
.debt .row3 input:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.field .row2 > *, .row2 .input { min-width: 0; }
.seg { display: inline-flex; border: 1px solid var(--axis); border-radius: 8px; overflow: hidden; }
.seg button { border: 0; border-radius: 0; background: var(--page); padding: 7px 12px; font-weight: 500; }
.seg button[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); }

/* Articles */
.article { max-width: 740px; }
.article h2:first-child { margin-top: 1em; }
.formula { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 10px 14px; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .9rem; overflow-x: auto; margin: 0 0 1em; }
.faq details { border-bottom: 1px solid var(--border); padding: 10px 0; }
.faq summary { cursor: pointer; font-weight: 600; }
.faq details p { margin: 8px 0 0; color: var(--ink-2); }
.related { display: flex; gap: 10px 18px; flex-wrap: wrap; padding: 0; list-style: none; }
.byline { color: var(--ink-3); font-size: .9rem; margin: 6px 0 24px; }
.byline a { color: var(--ink-2); }
.author-box { max-width: 740px; margin: 32px 0 0; padding: 16px 18px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; font-size: .95rem; color: var(--ink-2); }
.author-box .author-name { font-weight: 650; color: var(--ink); margin-bottom: 4px; }
.author-box p:last-child { margin-bottom: 0; }
.disclosure { font-size: .85rem; color: var(--ink-2); border-left: 3px solid var(--axis); padding-left: 12px; margin: 24px 0; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

@media (forced-colors: active) {
  .key, .splitbar span { border: 1px solid CanvasText; }
}
@media print {
  .site-header, .site-footer nav, .related { display: none; }
  .panel { box-shadow: none; }
}