/* StableMath — clean, credible, fast. Mobile-first. No frameworks. */
:root {
  --green: #2e5d3f;
  --green-dark: #1f422c;
  --tan: #f7f3ea;
  --ink: #26241f;
  --muted: #6b655a;
  --line: #e3dccb;
  --accent: #0f766e;
  --card: #ffffff;
  --radius: 10px;
}
:root {
  --ink: #1f2a2a; --muted: #5c6b6b; --bg: #f7f9f8; --surface: #ffffff;
  --border: #dde5e2; --accent: #0f766e; --accent-ink: #ffffff;
  --accent-dark: #0b5a54; --accent-soft: #e6f4f2; --accent-d: #0b5a54;
  --card: var(--surface); --line: var(--border); --sky: var(--accent);
  --radius: 14px; --shadow: 0 8px 28px rgba(16, 24, 40, .10);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--tan);
  line-height: 1.6;
  font-size: 17px;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 0 18px; }

/* Header / nav */
.site-header { background: var(--green-dark); color: #fff; }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; padding-top: 14px; padding-bottom: 14px; }
.brand { color: #fff; text-decoration: none; font-weight: 700; font-size: 1.25rem; letter-spacing: .2px; }
.brand span { color: inherit; }
nav.main a { color: #e9e2d2; text-decoration: none; margin-left: 16px; font-size: .95rem; }
nav.main a:hover { color: #fff; text-decoration: underline; }

/* Hero */
.hero { background: var(--green); color: #fff; padding: 34px 0 30px; }
.hero h1 { margin: 0 0 10px; font-size: 1.7rem; line-height: 1.25; }
.hero p { margin: 0; color: #e6dfcc; max-width: 60ch; }
.hero p strong { color: #fff; }

/* Cards / calculator */
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  margin: 22px 0;
  box-shadow: 0 1px 3px rgba(0,0,0,.05);
}
.card h2 { margin-top: 0; font-size: 1.3rem; color: var(--green-dark); }
.field { margin: 14px 0; }
.field label { display: block; font-weight: 600; margin-bottom: 6px; }
.field .hint { font-weight: 400; color: var(--muted); font-size: .88rem; display: block; margin-top: 4px; }
input[type="number"], select {
  width: 100%; padding: 11px 12px; font-size: 1rem;
  border: 1px solid #c9c2b0; border-radius: 6px; background: #fffdf8; color: var(--ink);
}
input[type="number"]:focus, select:focus { outline: 2px solid var(--green); border-color: var(--green); }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
button.calc-btn {
  background: var(--green); color: #fff; border: 0; border-radius: 6px;
  padding: 13px 22px; font-size: 1.05rem; font-weight: 700; cursor: pointer; width: 100%;
}
button.calc-btn:hover { background: var(--green-dark); }

/* Results */
.results { display: none; border-top: 2px solid var(--green); margin-top: 20px; padding-top: 16px; }
.results.show { display: block; }
.result-big { font-size: 1.5rem; font-weight: 800; color: var(--green-dark); margin: 4px 0 2px; }
table.lines { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: .96rem; }
table.lines th, table.lines td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); }
table.lines td.num, table.lines th.num { text-align: right; font-variant-numeric: tabular-nums; }
table.lines tr.total td { font-weight: 800; border-bottom: 0; font-size: 1.05rem; }
.math-note {
  background: #f2eee1; border-left: 4px solid var(--accent);
  padding: 12px 14px; font-size: .9rem; color: #4d463a; margin: 14px 0; border-radius: 0 6px 6px 0;
}
.math-note code { background: #e7e0cd; padding: 1px 5px; border-radius: 4px; font-size: .85rem; }
.caveat {
  background: #fdf6e3; border: 1px solid #e8d9a8; border-radius: 6px;
  padding: 12px 14px; font-size: .9rem; margin: 14px 0;
}
.caveat strong { color: #7a5c14; }

/* Content */
article.guide h1 { font-size: 1.6rem; color: var(--green-dark); line-height: 1.3; }
article.guide h2 { color: var(--green-dark); margin-top: 1.8em; font-size: 1.25rem; }
article.guide .lede { font-size: 1.08rem; color: #3d3a33; }
.sources { font-size: .88rem; color: var(--muted); border-top: 1px solid var(--line); margin-top: 2em; padding-top: 1em; }
.sources li { margin-bottom: 6px; }

/* FAQ */
.faq details { border: 1px solid var(--line); border-radius: 6px; background: #fff; margin: 10px 0; }
.faq summary { padding: 12px 14px; font-weight: 600; cursor: pointer; }
.faq details p { padding: 0 14px 14px; margin: 0; }

/* Related links */
.related { display: grid; gap: 12px; margin: 22px 0; }
.related a {
  display: block; background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 14px 16px; text-decoration: none; color: var(--ink);
}
.related a:hover { border-color: var(--green); }
.related a strong { color: var(--green-dark); display: block; }
.related a span { font-size: .9rem; color: var(--muted); }

/* Affiliate disclosure block */
.affiliate-note {
  border: 1px dashed #b9ad8f; border-radius: 6px; padding: 12px 14px;
  font-size: .85rem; color: var(--muted); margin: 22px 0; background: #fbf8f0;
}

/* Footer */
.site-footer { background: var(--green-dark); color: #cfc7b2; margin-top: 40px; padding: 26px 0; font-size: .88rem; }
.site-footer a { color: #e9e2d2; }
.site-footer p { margin: 6px 0; }

@media (min-width: 640px) {
  .hero h1 { font-size: 2.1rem; }
  .field-row.three { grid-template-columns: 1fr 1fr 1fr; }
}
/* ==== Unified design layer — FlintPass 2026-10-14 ==== */
body { font-size: 1.05rem; line-height: 1.65; color: var(--ink); background: var(--bg); }
h1 { font-size: 2.4rem; font-weight: 800; letter-spacing: -0.02em; line-height: 1.15; color: var(--ink); }
h2 { font-size: 1.55rem; font-weight: 700; letter-spacing: -0.01em; line-height: 1.25; color: var(--ink); }
h3 { font-size: 1.2rem; font-weight: 700; color: var(--ink); }
a { color: var(--accent-dark); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.site-header { background: var(--surface); color: var(--ink); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 50; }
.site-header .brand { color: var(--ink); }
.brand span { color: inherit; }
nav.main a { color: var(--muted); }
nav.main a:hover { color: var(--accent); }
.hero { padding-top: 3rem; padding-bottom: 2.5rem; }
.card { border-radius: 14px; border: 1px solid var(--border); }
.related a:hover { box-shadow: var(--shadow); }
button.calc, .calc-btn { background: var(--accent); color: var(--accent-ink); border: 1px solid var(--accent); border-radius: 10px; font-weight: 600; }
button.calc:hover, .calc-btn:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
th { background: var(--accent-soft); color: var(--ink); }
th, td { border-color: var(--border); }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
article.guide { max-width: 44rem; }
.site-footer { background: #141a22; color: #c3cedd; }
.site-footer a { color: #e6ecf5; }
@media (max-width: 640px) { table { display: block; overflow-x: auto; } }

/* Contrast fix — 2026-10-14: hero headings inherit the dark hero's light text, not the global ink */
.hero h1 { color: #fff; }