:root {
  --bg: #ffffff; --fg: #1a1a2e; --muted: #5a5a72; --accent: #2563eb;
  --accent-dark: #1e4fc4; --border: #e4e4ee; --card: #f7f7fb;
}
* { box-sizing: border-box; }
body {
  margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--fg); background: var(--bg); line-height: 1.65;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; color: var(--accent-dark); }
header {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 760px; margin: 0 auto; padding: 18px 20px;
  border-bottom: 1px solid var(--border);
}
.brand { font-weight: 700; font-size: 1.25rem; color: var(--fg); letter-spacing: -0.02em; }
.brand:hover { text-decoration: none; }
nav { display: flex; gap: 18px; font-size: 0.95rem; }
main { max-width: 760px; margin: 0 auto; padding: 36px 20px 60px; }
h1 { font-size: 1.9rem; letter-spacing: -0.02em; margin: 0 0 12px; }
h2 { font-size: 1.3rem; margin: 34px 0 10px; }
h3 { font-size: 1.05rem; margin: 0 0 6px; }
p { margin: 10px 0; }
.hero { padding: 24px 0 8px; }
.lede { font-size: 1.15rem; color: var(--muted); max-width: 60ch; }
.steps li { margin: 10px 0; }
.clusters { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 14px; margin-top: 14px; }
.cluster { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 16px; }
.cluster p { color: var(--muted); font-size: 0.92rem; margin: 4px 0 0; }
code { background: var(--card); border: 1px solid var(--border); border-radius: 5px; padding: 1px 6px; font-size: 0.9em; }
.trust { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 18px 20px; }
footer { border-top: 1px solid var(--border); padding: 26px 20px 40px; text-align: center; color: var(--muted); font-size: 0.9rem; }
.foot-links { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-bottom: 10px; }
footer p { margin: 6px 0 0; }
.crumbs { font-size: 0.88rem; color: var(--muted); margin-bottom: 6px; }
.crumbs a { color: var(--muted); }
.btn { display: inline-block; background: var(--accent); color: #fff; padding: 10px 18px; border-radius: 8px; font-weight: 600; margin-top: 10px; }
.btn:hover { background: var(--accent-dark); text-decoration: none; }
.calc { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 18px; margin: 20px 0; }
.calc-fields { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 14px 18px; }
.calc-field { display: block; font-size: 0.92rem; font-weight: 600; }
.calc-field input[type="number"] { width: 100%; margin-top: 4px; padding: 7px 8px; font-size: 1rem; border: 1px solid var(--border); border-radius: 6px; }
.range-row { display: flex; align-items: center; gap: 10px; margin-top: 4px; }
.range-row input[type="range"] { flex: 1; }
.calc-out { font-variant-numeric: tabular-nums; font-weight: 700; min-width: 64px; text-align: right; }
.calc-results { margin-top: 16px; }
.calc-big { font-size: 1.45rem; font-weight: 700; margin: 4px 0; }
.calc-sub { color: var(--muted); font-size: 0.95rem; }
.calc-table { width: 100%; border-collapse: collapse; margin: 10px 0; font-size: 0.92rem; }
.calc-table th, .calc-table td { padding: 5px 8px; text-align: right; border-bottom: 1px solid var(--border); }
.calc-table th:first-child, .calc-table td:first-child { text-align: left; }
.calc-table tr.best { background: #eef4ff; font-weight: 700; }
.calc-compare { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 10px 0; }
.calc-opt { border: 1px solid var(--border); border-radius: 8px; padding: 12px; }
.calc-opt.best { border-color: var(--accent); background: #eef4ff; }
.calc-note { color: var(--muted); font-size: 0.9rem; margin-top: 10px; }
.calc-warn { background: #fff4e5; border: 1px solid #f0c27a; border-radius: 8px; padding: 10px 12px; margin-top: 10px; font-size: 0.95rem; }
.calc-verdict { font-weight: 700; margin: 8px 0; }
.calc-verdict.good { color: #15803d; }
.calc-verdict.bad { color: #b91c1c; }
.assumptions { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 14px 18px; margin: 22px 0; }
.assumptions ul { margin: 6px 0 2px; padding-left: 20px; }
.assumptions li { margin: 5px 0; color: var(--muted); font-size: 0.93rem; }
details.faq { border: 1px solid var(--border); border-radius: 8px; padding: 10px 14px; margin: 8px 0; background: var(--card); }
details.faq summary { font-weight: 600; cursor: pointer; }
details.faq p { margin: 8px 0 2px; color: var(--muted); }
@media (max-width: 560px) { .calc-compare { grid-template-columns: 1fr; } .calc-fields { grid-template-columns: 1fr; } }