:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --border: #e2e8f0;
  --accent: #0f766e;
  --accent-strong: #115e59;
  --accent-soft: #ccfbf1;
  --warn: #b45309;
  --radius: 12px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1220;
    --surface: #111a2e;
    --text: #e2e8f0;
    --muted: #94a3b8;
    --border: #1e293b;
    --accent: #2dd4bf;
    --accent-strong: #5eead4;
    --accent-soft: #134e4a;
    --warn: #fbbf24;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, sans-serif;
}

a { color: var(--accent); }
a:hover { color: var(--accent-strong); }

.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 56px; }
.brand { font-weight: 800; font-size: 1.15rem; text-decoration: none; color: var(--text); }
.site-header nav { display: flex; gap: 16px; }
.site-header nav a { text-decoration: none; font-weight: 600; }

main { padding: 8px 0 40px; }

h1 { font-size: clamp(1.5rem, 4vw, 2.1rem); line-height: 1.2; margin: 16px 0 8px; }
h2 { font-size: 1.3rem; line-height: 1.3; margin: 32px 0 8px; }

.meta, .small { color: var(--muted); font-size: 0.9rem; }

.crumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; padding: 0 16px; margin: 12px auto 0; max-width: 760px; font-size: 0.9rem; color: var(--muted); }
.crumbs li + li::before { content: "›"; margin-right: 6px; }

.hero { padding: 24px 0 8px; }
.hero p { font-size: 1.1rem; color: var(--muted); }

.calc { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin: 20px 0; display: grid; gap: 16px; }
@media (min-width: 720px) { .calc { grid-template-columns: 1fr 1fr; align-items: start; } }
.calc > * { min-width: 0; }

.calc-form { display: grid; gap: 12px; }
.field { display: grid; gap: 4px; }
.field label { font-weight: 600; font-size: 0.95rem; }
.field small { color: var(--muted); font-size: 0.82rem; }
input, select {
  width: 100%;
  font: inherit;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
}
input:focus, select:focus { outline: 2px solid var(--accent); outline-offset: 1px; }

button, .button {
  display: inline-block;
  font: inherit;
  font-weight: 700;
  padding: 11px 18px;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  cursor: pointer;
  text-align: center;
}
@media (prefers-color-scheme: dark) { button, .button { color: #04201d; } }
button:hover, .button:hover { background: var(--accent-strong); color: #fff; }

.calc-result { background: var(--accent-soft); border-radius: 10px; padding: 14px; min-height: 120px; }
.calc-total { display: grid; gap: 2px; margin-bottom: 10px; }
.calc-total span { font-size: 0.9rem; }
.calc-total strong { font-size: 1.9rem; line-height: 1.1; }
.calc-rows { margin: 0; display: grid; gap: 6px; }
.calc-rows div { display: flex; justify-content: space-between; gap: 12px; border-top: 1px dashed var(--border); padding-top: 6px; }
.calc-rows dt { font-size: 0.92rem; }
.calc-rows dd { margin: 0; font-weight: 700; text-align: right; overflow-wrap: anywhere; }
.calc-rows dd.num { white-space: nowrap; }
.calc-note { font-size: 0.85rem; color: var(--muted); margin: 10px 0 0; }
.calc-error { color: var(--warn); font-weight: 600; }
.calc-table { margin-top: 12px; }

.formula { background: var(--surface); border-left: 4px solid var(--accent); padding: 10px 14px; border-radius: 6px; font-weight: 600; }

table { border-collapse: collapse; width: 100%; font-size: 0.92rem; background: var(--surface); }
th, td { border: 1px solid var(--border); padding: 8px; text-align: left; vertical-align: top; }
th { background: var(--bg); }
.table-scroll { overflow-x: auto; max-width: 100%; }
.calc-table .table-scroll { max-height: 360px; overflow-y: auto; }

details { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 10px 14px; margin: 8px 0; }
summary { cursor: pointer; font-weight: 600; }

.cta { background: var(--surface); border: 2px solid var(--accent); border-radius: var(--radius); padding: 16px; margin: 24px 0; }
.cta h2 { margin-top: 4px; }
.cta-kicker { margin: 0; color: var(--accent); font-weight: 700; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.04em; }

.share { font-size: 0.95rem; }

.cards { list-style: none; padding: 0; display: grid; gap: 12px; }
@media (min-width: 640px) { .cards { grid-template-columns: 1fr 1fr; } }
.cards a { display: grid; gap: 4px; height: 100%; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; text-decoration: none; color: var(--text); }
.cards a:hover { border-color: var(--accent); }
.cards span { color: var(--muted); font-size: 0.9rem; }

.related, .sources { padding-left: 20px; }

.site-footer { border-top: 1px solid var(--border); background: var(--surface); padding: 20px 0; }
.footer-links { display: flex; flex-wrap: wrap; gap: 14px; }