:root {
  --bg: #f6f6f3;
  --card: #ffffff;
  --text: #1d1d1b;
  --muted: #6b6b66;
  --line: #deded8;
  --accent: #2f5d8a;
  --ok: #2f7a3e;
  --bad: #b3261e;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 15px;
  color: var(--text);
  background: var(--bg);
}

[hidden] { display: none !important; }
* { box-sizing: border-box; }
body { margin: 0; padding: 0 16px 48px; }

.topbar {
  display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
  max-width: 1100px; margin: 0 auto; padding: 14px 0;
}
.topbar nav { display: flex; gap: 4px; }
.spacer { flex: 1; }

.card {
  max-width: 1100px; margin: 12px auto; padding: 16px 20px;
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
}
.card.narrow { max-width: 380px; margin-top: 12vh; }

h1 { margin: 0 0 8px; font-size: 22px; }
h2 { margin: 0; font-size: 17px; }
h3 { margin: 16px 0 6px; font-size: 14px; color: var(--muted); font-weight: 600; }

label { display: flex; flex-direction: column; gap: 4px; margin: 10px 0; font-size: 13px; color: var(--muted); }
input, select, textarea {
  font: inherit; color: var(--text); background: #fff;
  border: 1px solid var(--line); border-radius: 6px; padding: 7px 9px; width: 100%;
}
textarea { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 13px; resize: vertical; }

button {
  font: inherit; cursor: pointer; border-radius: 6px; padding: 8px 16px;
  border: 1px solid var(--accent); background: var(--accent); color: #fff;
}
button:disabled { opacity: .5; cursor: progress; }
button.link, button.tab { background: transparent; color: var(--accent); border-color: transparent; padding: 6px 10px; }
button.tab.active { border-color: var(--line); background: var(--card); color: var(--text); }

.row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 0 14px; }
fieldset { border: 1px solid var(--line); border-radius: 8px; margin: 12px 0; padding: 4px 14px 8px; }
legend { color: var(--muted); font-size: 13px; padding: 0 6px; }

.muted { color: var(--muted); }
.small { font-size: 12px; margin: 0; }
.ok { color: var(--ok); }
.bad { color: var(--bad); }

.checks { list-style: none; margin: 10px 0 0; padding: 0; }
.checks li { padding: 3px 0; color: var(--text); }
.checks .mark { display: inline-block; width: 20px; font-weight: 700; }
.checks li.ok .mark { color: var(--ok); }
.checks li.bad .mark { color: var(--bad); }

.result { margin-top: 16px; border-top: 1px solid var(--line); padding-top: 8px; }
pre {
  white-space: pre-wrap; word-break: break-word; margin: 0;
  background: #fafaf7; border: 1px solid var(--line); border-radius: 6px; padding: 10px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 13px;
}
pre.answer { font-size: 14px; }
details { margin-top: 10px; }
summary { cursor: pointer; color: var(--accent); }

table.kv { border-collapse: collapse; font-size: 13px; }
table.kv th { text-align: left; font-weight: 400; color: var(--muted); padding: 2px 16px 2px 0; }
table.kv td { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; padding: 2px 0; }