:root {
  --ink: #111827;
  --muted: #4b5563;
  --line: #e5e7eb;
  --bg: #f5f7fb;
  --card: #fff;
  --brand: #1976d2;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
}
a { color: var(--brand); }
.wrap { max-width: 52rem; margin: 0 auto; padding: 1.25rem 1.25rem 3rem; }
header {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0 1.25rem;
  border-bottom: 1px solid var(--line);
}
.brand { font-weight: 700; font-size: 1.25rem; color: var(--ink); text-decoration: none; }
nav a { margin-right: 0.9rem; text-decoration: none; }
nav a:hover { text-decoration: underline; }
.crumbs { list-style: none; padding: 0; margin: 1rem 0; font-size: 0.9rem; color: var(--muted); }
.crumbs li { display: inline; }
.crumbs li + li::before { content: " / "; color: #9ca3af; }
h1 { font-size: clamp(1.6rem, 4vw, 2.4rem); line-height: 1.2; margin: 0.4rem 0 1rem; }
h2 { font-size: 1.25rem; margin: 2rem 0 0.6rem; }
p { margin: 0 0 1rem; }
ul { margin: 0 0 1rem; padding-left: 1.2rem; }
.lede { font-size: 1.1rem; color: var(--muted); }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.1rem 1.2rem;
  margin: 1rem 0;
}
footer { margin-top: 2.5rem; padding-top: 1rem; border-top: 1px solid var(--line); color: var(--muted); font-size: 0.95rem; }
footer a { margin-right: 0.75rem; }
label { display: block; font-weight: 600; margin: 0.85rem 0 0.3rem; }
input, select, textarea {
  width: 100%;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  font: inherit;
  background: #fff;
}
textarea { min-height: 6rem; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
button.btn, .btn {
  display: inline-block;
  margin-top: 1rem;
  background: var(--brand);
  color: #fff;
  border: 0;
  padding: 0.7rem 1.15rem;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
}
.ok { color: #166534; }
.err { color: #b91c1c; }