:root {
  --bg: #f5f9f8;
  --surface: #ffffff;
  --ink: #112127;
  --muted: #475c64;
  --line: #d3dfe1;
  --accent: #0a6a86;
  --accent-ink: #ffffff;
  --accent-soft: #e0f1f5;
  --warn-ink: #7a4300;
  --warn-bg: #fff3df;
  --warn-line: #f0cf9a;
  --ok-ink: #17603d;
  --ok-bg: #e3f4ea;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(17, 33, 39, .06), 0 8px 24px rgba(17, 33, 39, .06);
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e191e; --surface: #15252c; --ink: #e8f1f3; --muted: #a2b6bd; --line: #2a3f47;
    --accent: #55c1dc; --accent-ink: #06222b; --accent-soft: #133743;
    --warn-ink: #ffd699; --warn-bg: #3a2a10; --warn-line: #6b4d1c;
    --ok-ink: #8fe0b2; --ok-bg: #123424;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px rgba(0, 0, 0, .3);
  }
}
:root[data-theme="dark"] {
  --bg: #0e191e; --surface: #15252c; --ink: #e8f1f3; --muted: #a2b6bd; --line: #2a3f47;
  --accent: #55c1dc; --accent-ink: #06222b; --accent-soft: #133743;
  --warn-ink: #ffd699; --warn-bg: #3a2a10; --warn-line: #6b4d1c;
  --ok-ink: #8fe0b2; --ok-bg: #123424;
}
:root[data-contrast="high"] {
  --bg: #000; --surface: #000; --ink: #fff; --muted: #fff; --line: #fff;
  --accent: #ffe14d; --accent-ink: #000; --accent-soft: #000;
  --warn-ink: #fff; --warn-bg: #000; --warn-line: #ffe14d;
  --ok-ink: #fff; --ok-bg: #000; --shadow: none;
}
:root[data-contrast="high"] a { text-decoration: underline; }
:root[data-contrast="high"] .card, :root[data-contrast="high"] .callout, :root[data-contrast="high"] .pick { border: 2px solid #fff; }

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink); font-family: var(--font);
  font-size: 1.0625rem; line-height: 1.6;
}
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
.skip { position: absolute; left: -999px; top: 0; background: var(--accent); color: var(--accent-ink); padding: .6rem 1rem; z-index: 10; }
.skip:focus { left: 8px; top: 8px; }
.wrap { width: 100%; max-width: 66rem; margin: 0 auto; padding: 0 1.25rem; }
.narrow { max-width: 44rem; }

/* header */
.site-header { border-bottom: 1px solid var(--line); background: var(--surface); }
.site-header .wrap { display: flex; align-items: center; gap: 1.5rem; flex-wrap: wrap; padding-top: .9rem; padding-bottom: .9rem; }
.brand { display: inline-flex; align-items: center; gap: .55rem; font-weight: 750; font-size: 1.35rem; letter-spacing: -.02em; color: var(--ink); text-decoration: none; }
.brand svg { width: 28px; height: 28px; }
.nav { display: flex; gap: 1.25rem; flex-wrap: wrap; margin-left: auto; align-items: center; }
.nav a { color: var(--muted); text-decoration: none; font-size: .98rem; padding: .25rem 0; border-bottom: 2px solid transparent; }
.nav a:hover, .nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--accent); }
.hc-toggle { font: inherit; font-size: .88rem; color: var(--muted); background: none; border: 1px solid var(--line); border-radius: 999px; padding: .3rem .8rem; cursor: pointer; }
.hc-toggle[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }

/* type */
h1, h2, h3 { line-height: 1.2; letter-spacing: -.02em; margin: 0 0 .6rem; }
h1 { font-size: clamp(2rem, 4.6vw, 3.1rem); font-weight: 780; }
h2 { font-size: clamp(1.4rem, 2.8vw, 1.85rem); font-weight: 720; margin-top: 2.4rem; }
h3 { font-size: 1.15rem; font-weight: 700; margin-top: 1.6rem; }
p, ul, ol { margin: 0 0 1rem; }
.lead { font-size: 1.2rem; color: var(--muted); max-width: 40rem; }
.eyebrow { text-transform: uppercase; letter-spacing: .08em; font-size: .8rem; font-weight: 700; color: var(--accent); margin-bottom: .5rem; }
.muted { color: var(--muted); }
.small { font-size: .9rem; }

/* hero */
.hero { padding: 3rem 0 1.5rem; }
.hero h1 { max-width: 15em; }

/* cards */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 1.5rem; }
.grid { display: grid; gap: 1rem; }
.grid.three { grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); }
.grid.two { grid-template-columns: repeat(auto-fit, minmax(19rem, 1fr)); }
.card h3 { margin-top: 0; }
.card a.cardlink { text-decoration: none; color: inherit; }
.card a.cardlink:hover h3 { text-decoration: underline; }
.step-n { display: inline-grid; place-items: center; width: 2rem; height: 2rem; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 750; margin-bottom: .6rem; }

/* callouts */
.callout { border-radius: 12px; padding: .9rem 1.1rem; margin: 1rem 0; border: 1px solid var(--line); background: var(--accent-soft); }
.callout.warn { background: var(--warn-bg); border-color: var(--warn-line); color: var(--warn-ink); }
.callout.ok { background: var(--ok-bg); color: var(--ok-ink); border-color: transparent; }
.callout p:last-child { margin-bottom: 0; }

/* tools */
.tool { margin: 1rem 0 2rem; }
.tabs { display: flex; gap: .4rem; flex-wrap: wrap; margin-bottom: 1.2rem; }
.tab { font: inherit; font-weight: 650; border: 1px solid var(--line); background: var(--surface); color: var(--ink); padding: .55rem 1.1rem; border-radius: 999px; cursor: pointer; }
.tab[aria-selected="true"] { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.panel[hidden] { display: none; }
fieldset { border: 0; padding: 0; margin: 0 0 1.2rem; min-width: 0; }
legend, label.lbl { font-weight: 650; display: block; margin-bottom: .35rem; padding: 0; }
.hint { color: var(--muted); font-size: .9rem; margin-top: .25rem; }
.fields { display: grid; gap: 1rem 1.25rem; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); margin-bottom: 1rem; }
input[type="number"], select {
  font: inherit; width: 100%; padding: .6rem .75rem; border: 1px solid var(--line); border-radius: 10px;
  background: var(--bg); color: var(--ink);
}
.checks { display: grid; gap: .4rem .9rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); }
.check { display: flex; gap: .55rem; align-items: flex-start; padding: .45rem .6rem; border: 1px solid var(--line); border-radius: 10px; background: var(--bg); cursor: pointer; }
.check input { margin-top: .3rem; accent-color: var(--accent); width: 1.05rem; height: 1.05rem; }
.btn { font: inherit; font-weight: 650; background: var(--accent); color: var(--accent-ink); border: 0; border-radius: 10px; padding: .7rem 1.3rem; cursor: pointer; text-decoration: none; display: inline-block; }
.btn.secondary { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.btn:hover { filter: brightness(1.08); }
.result { margin-top: 1.5rem; border-top: 1px solid var(--line); padding-top: 1.25rem; }
.result[hidden] { display: none; }
.big { font-size: 1.6rem; font-weight: 760; letter-spacing: -.02em; }
.working { margin: .5rem 0 1rem; padding-left: 1.1rem; color: var(--muted); }
.picks { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); margin: 1rem 0; }
.pick { border: 1px solid var(--line); border-radius: 12px; padding: 1rem; background: var(--bg); }
.pick h4 { margin: 0 0 .15rem; font-size: 1.05rem; }
.badge { display: inline-block; font-size: .75rem; font-weight: 700; letter-spacing: .02em; padding: .12rem .55rem; border-radius: 999px; background: var(--accent-soft); color: var(--accent); margin: 0 .3rem .3rem 0; }
.badge.warn { background: var(--warn-bg); color: var(--warn-ink); border: 1px solid var(--warn-line); }
.badge.ok { background: var(--ok-bg); color: var(--ok-ink); }
.kv { margin: .5rem 0; font-size: .95rem; }
.kv div { display: flex; justify-content: space-between; gap: 1rem; border-bottom: 1px dashed var(--line); padding: .2rem 0; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; text-align: right; }

/* tables */
.tablewrap { overflow-x: auto; margin: 1rem 0; }
table { border-collapse: collapse; width: 100%; font-size: .97rem; }
th, td { text-align: left; padding: .55rem .7rem; border-bottom: 1px solid var(--line); vertical-align: top; }
th { background: var(--accent-soft); font-weight: 700; }

/* lists of units */
.unitlist { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(17rem, 1fr)); margin: 1rem 0 2rem; }
.unit { display: flex; flex-direction: column; gap: .4rem; }
.unit h3 { margin: 0; }
.unit p { margin: 0; color: var(--muted); font-size: .95rem; }

/* article */
.article { padding: 2rem 0 3rem; }
.article h1 { font-size: clamp(1.9rem, 4vw, 2.6rem); }
.article .meta { color: var(--muted); font-size: .92rem; margin-bottom: 1.5rem; }
.article ul, .article ol { padding-left: 1.3rem; }
.article li { margin-bottom: .4rem; }
.sources { font-size: .93rem; color: var(--muted); border-top: 1px solid var(--line); margin-top: 2.5rem; padding-top: 1rem; }
.crumbs { font-size: .9rem; color: var(--muted); margin-bottom: .8rem; }
.crumbs a { color: var(--muted); }

/* footer */
.site-footer { border-top: 1px solid var(--line); background: var(--surface); margin-top: 3rem; padding: 2rem 0; font-size: .95rem; color: var(--muted); }
.site-footer .cols { display: grid; gap: 1.5rem; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); }
.site-footer a { color: var(--muted); }
.site-footer h2 { font-size: .85rem; text-transform: uppercase; letter-spacing: .08em; margin: 0 0 .5rem; color: var(--ink); }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: .3rem; }

@media (max-width: 40rem) {
  body { font-size: 1rem; }
  .nav { margin-left: 0; gap: 1rem; }
  .card { padding: 1.1rem; }
  .hero { padding-top: 2rem; }
}
@media print { .site-header, .site-footer, .tabs, .btn { display: none; } }