:root {
  --bg: #f6f3ee;
  --card: #fffdf9;
  --ink: #1b1a17;
  --muted: #5f5b53;
  --line: #ddd6ca;
  --accent: #c2410c;
  --on-accent: #ffffff;
  --ok: #1f7a3d;
  --warn: #8a5a00;
  --poor: #b42318;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14110f;
    --card: #1c1815;
    --ink: #f3efe8;
    --muted: #aaa397;
    --line: #2f2a25;
    --accent: #ff7a45;
    --on-accent: #14110f;
    --ok: #5fd38a;
    --warn: #f2b84b;
    --poor: #ff8a80;
  }
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 1rem/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

h1, h2 { line-height: 1.15; letter-spacing: -0.02em; }
h1 { font-size: clamp(2rem, 6vw, 3rem); margin: 0; }
h2 { font-size: 1.35rem; margin: 0 0 1rem; }
p { margin: 0 0 0.75rem; }
small { font-weight: 400; color: var(--muted); }

:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.skip {
  position: absolute; left: 1rem; top: -4rem;
  background: var(--ink); color: var(--bg); padding: 0.5rem 0.75rem; border-radius: 6px;
}
.skip:focus { top: 1rem; }

.top, main, .foot { width: min(880px, 100% - 2rem); margin-inline: auto; }

.top { padding: 1.25rem 0 0; }
.brand {
  display: inline-flex; align-items: center; gap: 0.6rem;
  color: var(--accent); font-weight: 750; font-size: 1.15rem;
  letter-spacing: -0.01em; text-decoration: none;
}

.hero { text-align: center; padding: 2.5rem 0 2rem; }
.lede { color: var(--muted); margin-top: 0.75rem; }

.gauge { position: relative; width: min(300px, 78vw); aspect-ratio: 1; margin: 1.5rem auto 0; }
.gauge svg { width: 100%; height: 100%; display: block; }
.gauge circle { fill: none; stroke-width: 12; stroke-linecap: round; }
.gauge .track { stroke: var(--line); stroke-dasharray: 405.3 540.4; }
.gauge .fill {
  stroke: var(--accent);
  stroke-dasharray: 0 540.4;
  opacity: 0;
  transition: stroke-dasharray 0.25s linear, opacity 0.15s;
}

.gauge-text {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 0.15rem;
}
.phase { color: var(--muted); font-size: 0.9rem; text-transform: uppercase; letter-spacing: 0.1em; }
.reading {
  font-size: clamp(2.8rem, 12vw, 4rem); font-weight: 700; line-height: 1;
  font-variant-numeric: tabular-nums;
}
.reading-unit { color: var(--muted); }

.status { margin: 1.25rem 0 1rem; color: var(--muted); min-height: 1.55em; }

.go {
  appearance: none; border: 0; cursor: pointer;
  background: var(--accent); color: var(--on-accent);
  font: inherit; font-size: 1.5rem; font-weight: 700;
  padding: 1rem 4rem; min-height: 64px; min-width: 180px; border-radius: 999px;
  transition: transform 0.12s ease;
}
.go:hover { transform: translateY(-1px); }
.go:active { transform: translateY(1px); }
.go.running {
  background: transparent; color: var(--accent);
  box-shadow: inset 0 0 0 2px var(--accent);
}

.error { color: var(--poor); font-weight: 600; margin-top: 1rem; }

.block { padding: 1.75rem 0; border-top: 1px solid var(--line); }

.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 0.75rem; margin: 0; }
.tile { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 0.9rem 1rem; }
.tile dt { color: var(--muted); font-size: 0.9rem; }
.tile dd { margin: 0.25rem 0 0; }
.num { font-size: 2rem; font-weight: 700; font-variant-numeric: tabular-nums; line-height: 1.1; }
.unit { color: var(--muted); font-size: 0.95rem; }
.sub { display: block; color: var(--muted); font-size: 0.85rem; margin-top: 0.15rem; }

.note { color: var(--muted); font-size: 0.92rem; margin-top: 0.75rem; }

.verdicts { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 0.75rem; }
.verdicts li { background: var(--card); border: 1px solid var(--line); border-left-width: 5px; border-radius: 12px; padding: 0.9rem 1rem; }
.verdicts li.ok { border-left-color: var(--ok); }
.verdicts li.warn { border-left-color: var(--warn); }
.verdicts li.poor { border-left-color: var(--poor); }
.verdicts .head { display: flex; justify-content: space-between; gap: 0.75rem; align-items: baseline; font-weight: 650; }
.badge { font-size: 0.9rem; font-weight: 700; white-space: nowrap; }
.ok .badge { color: var(--ok); }
.warn .badge { color: var(--warn); }
.poor .badge { color: var(--poor); }
.verdicts p { color: var(--muted); font-size: 0.92rem; margin: 0.4rem 0 0; }

.facts { margin: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 0.5rem 1.5rem; }
.facts div { display: flex; justify-content: space-between; gap: 1rem; border-bottom: 1px solid var(--line); padding: 0.45rem 0; }
.facts dt { color: var(--muted); }
.facts dd { margin: 0; font-weight: 600; text-align: right; }

.calc { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; }
.calc label { display: grid; gap: 0.35rem; font-weight: 600; font-size: 0.95rem; }
.calc .row { display: flex; gap: 0.5rem; }
input, select {
  font: inherit; color: var(--ink); background: var(--card);
  border: 1px solid var(--line); border-radius: 8px; padding: 0.6rem 0.75rem; min-height: 44px; width: 100%;
}
.calc .row select { width: auto; }
.calc-out { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin: 1rem 0 0; }
.calc-out div { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 0.8rem 1rem; }
.calc-out dt { color: var(--muted); font-size: 0.9rem; }
.calc-out dd { margin: 0.2rem 0 0; font-size: 1.4rem; font-weight: 700; font-variant-numeric: tabular-nums; }

.faq details { border-top: 1px solid var(--line); padding: 0.85rem 0; }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; font-weight: 650; }
.faq details p { color: var(--muted); margin: 0.6rem 0 0; }

.foot { color: var(--muted); font-size: 0.88rem; padding: 1.5rem 0 3rem; border-top: 1px solid var(--line); }

@media (max-width: 480px) {
  .go { width: 100%; padding-inline: 1rem; }
}

@media (prefers-reduced-motion: reduce) {
  .gauge .fill, .go { transition: none; }
}