:root {
  --bg: #ffffff;
  --fg: #111827;
  --muted: #6b7280;
  --line: #e5e7eb;
  --card: #f9fafb;
  --accent: #2563eb;
  --accent-fg: #ffffff;
  --ok: #15803d;
  --bad: #b91c1c;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1020;
    --fg: #e5e7eb;
    --muted: #9ca3af;
    --line: #1f2937;
    --card: #111827;
    --accent: #3b82f6;
    --ok: #4ade80;
    --bad: #f87171;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
a { color: var(--accent); }
code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.92em;
  background: var(--card);
  border: 1px solid var(--line);
  padding: 1px 6px;
  border-radius: 6px;
}
.wrap { max-width: 860px; margin: 0 auto; padding: 0 20px; }
.sr { position: absolute; left: -9999px; }

.site-header { border-bottom: 1px solid var(--line); }
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; flex-wrap: wrap; padding-top: 14px; padding-bottom: 14px;
}
.brand { font-weight: 700; color: var(--fg); text-decoration: none; font-size: 18px; }
nav { display: flex; gap: 18px; }
nav a { color: var(--muted); text-decoration: none; font-size: 15px; }
nav a:hover { color: var(--fg); }

.hero { padding: 56px 0 32px; }
h1 { font-size: clamp(28px, 5vw, 40px); line-height: 1.2; margin: 0 0 14px; }
h2 { font-size: 20px; margin: 28px 0 8px; }
.lead { color: var(--muted); font-size: 18px; max-width: 640px; margin: 0 0 24px; }

.check { display: flex; gap: 10px; max-width: 520px; }
.check input {
  flex: 1; min-width: 0; padding: 11px 14px; font-size: 16px;
  border: 1px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--fg);
}
.check input:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.check button {
  padding: 11px 18px; font-size: 16px; font-weight: 600; cursor: pointer;
  border: 0; border-radius: 10px; background: var(--accent); color: var(--accent-fg);
  white-space: nowrap;
}
.result { margin-top: 18px; max-width: 520px; }
.result ul { list-style: none; padding: 0; margin: 0; }
.result li { padding: 8px 0; border-bottom: 1px solid var(--line); }
.result .ok { color: var(--ok); font-weight: 600; }
.result .bad { color: var(--bad); font-weight: 600; }
.result p { margin: 12px 0 0; }

.cards {
  display: grid; gap: 16px; padding: 16px 0 56px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 18px; }
.card h2 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); }

.prose { padding-top: 40px; padding-bottom: 56px; max-width: 720px; }
.prose .meta { color: var(--muted); margin-top: -6px; }
.prose li { margin: 6px 0; }

.site-footer { border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
.site-footer .wrap {
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
  padding-top: 18px; padding-bottom: 18px;
}
.site-footer a { color: var(--muted); }