:root {
  --bg: #0f1419;
  --panel: #161d26;
  --line: #26313d;
  --text: #e6edf3;
  --muted: #9aa7b4;
  --accent: #f97316;
  --accent-soft: #1d2733;
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f8fa;
    --panel: #ffffff;
    --line: #e3e7ec;
    --text: #16202b;
    --muted: #5b6b7b;
    --accent: #c2410c;
    --accent-soft: #fff4ea;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: 960px; margin: 0 auto; padding: 0 20px; }

.site-header { border-bottom: 1px solid var(--line); background: var(--panel); }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 20px; }
.brand { font-weight: 700; font-size: 18px; color: var(--text); letter-spacing: -0.02em; }
.brand span { color: var(--accent); }
.nav { display: flex; gap: 18px; flex-wrap: wrap; }
.nav a { color: var(--muted); font-size: 14px; }
.nav a[aria-current="page"] { color: var(--text); font-weight: 600; }

.hero { padding: 48px 0 8px; }
.eyebrow { color: var(--accent); font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; margin: 0 0 10px; }
h1 { font-size: clamp(28px, 4vw, 40px); line-height: 1.15; margin: 0 0 12px; letter-spacing: -0.02em; }
.lead { color: var(--muted); max-width: 720px; margin: 0 0 12px; }

.calculator-card { background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 24px; margin: 24px auto 44px; }
.calculator-card h2 { margin: 0 0 16px; font-size: 18px; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; }
label { display: flex; flex-direction: column; gap: 6px; font-size: 13px; color: var(--muted); }
input, select {
  font: inherit; font-size: 15px; color: var(--text);
  background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 9px 10px;
}
.cta { margin-top: 18px; background: var(--accent); color: #fff; border: 0; border-radius: 8px; padding: 11px 22px; font-size: 15px; font-weight: 600; cursor: pointer; }
.cta:hover { filter: brightness(1.08); }

.results { margin-top: 26px; border-top: 1px solid var(--line); padding-top: 18px; }
.result-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; }
.metric { background: var(--accent-soft); border: 1px solid var(--line); border-radius: 10px; padding: 12px; display: flex; flex-direction: column; }
.metric-label { font-size: 12px; color: var(--muted); }
.metric-value { font-size: 24px; font-weight: 700; line-height: 1.2; }
.metric-unit { font-size: 12px; color: var(--muted); }
.note { font-size: 13px; color: var(--muted); margin-top: 14px; }

.prose { max-width: 760px; }
.prose h2 { margin-top: 34px; }
.prose table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14px; }
.prose th, .prose td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); }
.prose th { color: var(--muted); font-weight: 600; }

.site-footer { border-top: 1px solid var(--line); padding: 22px 0; color: var(--muted); font-size: 13px; margin-top: 30px; }