/* Thuli MF: one small stylesheet, no external fonts or trackers. */
:root {
  --ink: #1d2433;
  --muted: #5a6475;
  --bg: #fbfaf7;
  --card: #ffffff;
  --brand: #0f5c4d;      /* deep teal */
  --brand-ink: #ffffff;
  --accent: #e8f1ee;
  --line: #e3e1da;
  --warn-bg: #fff8e6;
  --warn-line: #e5c66b;
  --radius: 10px;
  --max: 920px;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Noto Sans Tamil", "Latha", sans-serif;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); line-height: 1.6; font-size: 17px; }
:lang(ta), .ta { font-family: "Noto Sans Tamil", "Latha", "Tamil MN", system-ui, sans-serif; line-height: 1.75; }
a { color: var(--brand); }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible { outline: 3px solid #f0a500; outline-offset: 2px; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 1.1rem; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 1rem; top: 1rem; background: #fff; padding: .5rem; z-index: 10; }

/* Header */
.site-header { background: var(--card); border-bottom: 1px solid var(--line); }
.site-header .wrap { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: .6rem; padding-top: .7rem; padding-bottom: .7rem; }
.brand { text-decoration: none; color: var(--ink); line-height: 1.2; }
.brand strong { font-size: 1.3rem; letter-spacing: .01em; color: var(--brand); }
.brand span { display: block; font-size: .85rem; color: var(--muted); }
nav ul { list-style: none; display: flex; flex-wrap: wrap; gap: .2rem .9rem; margin: 0; padding: 0; }
nav a { text-decoration: none; color: var(--ink); font-size: .95rem; padding: .25rem 0; }
nav a[aria-current="page"] { color: var(--brand); border-bottom: 2px solid var(--brand); }

/* ARN strip under header: disclosure at the start of every page */
.arn-strip { background: var(--accent); font-size: .88rem; color: var(--ink); }
.arn-strip .wrap { padding-top: .35rem; padding-bottom: .35rem; }

main { padding: 1.6rem 0 2.5rem; }
h1 { font-size: 1.85rem; line-height: 1.25; margin: .3rem 0 .8rem; }
h2 { font-size: 1.3rem; margin: 2rem 0 .6rem; }
h3 { font-size: 1.08rem; margin: 1.2rem 0 .3rem; }
.lead { font-size: 1.12rem; color: var(--muted); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.1rem 1.2rem; margin: 1rem 0; }
.grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid .card { margin: 0; }
.btn { display: inline-block; background: var(--brand); color: var(--brand-ink); text-decoration: none; border: 0; border-radius: 8px; padding: .7rem 1.1rem; font-size: 1rem; font-weight: 600; cursor: pointer; }
.btn.secondary { background: var(--card); color: var(--brand); border: 2px solid var(--brand); }
.btn-row { display: flex; flex-wrap: wrap; gap: .7rem; margin: 1.1rem 0; }
.warning { background: var(--warn-bg); border: 1px solid var(--warn-line); border-radius: var(--radius); padding: .8rem 1rem; font-weight: 600; }
.note { font-size: .92rem; color: var(--muted); }
.todo { background: #fdecec; border: 1px dashed #c0392b; padding: .2rem .4rem; border-radius: 4px; font-size: .9rem; }
table { border-collapse: collapse; width: 100%; font-size: .95rem; }
th, td { border-bottom: 1px solid var(--line); text-align: left; padding: .45rem .3rem; vertical-align: top; }

/* Calculator */
.calc label { display: block; font-weight: 600; margin-top: .9rem; }
.calc .hint { display: block; font-weight: 400; font-size: .88rem; color: var(--muted); }
.calc input { width: 100%; max-width: 320px; font-size: 1.05rem; padding: .55rem .6rem; border: 1px solid #b9b6ad; border-radius: 8px; background: #fff; }
.calc .row { display: grid; gap: 0 1.2rem; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.result { margin-top: 1.2rem; }
.result dl { display: grid; grid-template-columns: auto auto; gap: .3rem 1rem; margin: .4rem 0; }
.result dt { color: var(--muted); }
.result dd { margin: 0; font-weight: 700; text-align: right; }
.error { color: #b3261e; font-weight: 600; }

.contact-form { width: 100%; min-height: 980px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }

/* Footer */
.site-footer { background: #1d2433; color: #e9ecf2; font-size: .9rem; padding: 1.6rem 0 2rem; }
.site-footer a { color: #cfe7df; }
.site-footer .warning { background: transparent; border-color: #6b7488; color: #fff; }
.site-footer p { margin: .45rem 0; }

@media (max-width: 560px) {
  body { font-size: 16px; }
  h1 { font-size: 1.5rem; }
}
@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; } }
@media print { .site-header nav, .btn-row, .site-footer nav { display: none; } }