:root {
  --ink: #1d232b;
  --muted: #5a6470;
  --line: #d5dae0;
  --paper: #ffffff;
  --wash: #f4f6f8;
  --accent: #1f5fa8;
  --good: #1d6b3a;
  --bad: #9c2b23;
  --warn-bg: #fff6dc;
  --warn-line: #e7c766;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 0 16px 32px;
  background: var(--wash);
  color: var(--ink);
  font: 17px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

header, main, footer { max-width: 760px; margin: 0 auto; }
h1 { font-size: 1.6rem; margin: 20px 0 8px; }
h2 { font-size: 1.25rem; margin: 16px 0 4px; }
h3 { font-size: 1rem; margin: 0 0 4px; }

.notice {
  background: var(--warn-bg);
  border: 1px solid var(--warn-line);
  border-radius: 6px;
  padding: 8px 12px;
  margin: 8px 0;
}
.notice.small { font-size: 0.85rem; }
.notice:empty { display: none; }

nav { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
nav button[aria-pressed="true"] { background: var(--accent); color: #fff; border-color: var(--accent); }

section, form#open-form {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 16px;
  margin: 12px 0;
}
form#open-form { border: 0; padding: 0; }

fieldset { border: 1px solid var(--line); border-radius: 6px; margin: 0 0 12px; padding: 8px 12px; }
legend { font-weight: 600; padding: 0 4px; }
.choices { display: flex; flex-direction: column; gap: 4px; }
.choices label, label.option { display: block; cursor: pointer; }

button {
  font: inherit;
  padding: 6px 14px;
  border: 1px solid var(--muted);
  border-radius: 6px;
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
}
button[type="submit"] { background: var(--accent); color: #fff; border-color: var(--accent); }
button:disabled { opacity: 0.5; cursor: not-allowed; }

input[type="text"], input#code-input {
  font: inherit;
  padding: 4px 8px;
  border: 1px solid var(--muted);
  border-radius: 4px;
  max-width: 100%;
}
input#code-input { width: 20em; margin: 4px 8px 4px 0; text-transform: uppercase; }
.file-label { display: block; margin-top: 10px; }

.message p { color: var(--bad); font-weight: 600; margin: 8px 0; }
.actions { display: flex; gap: 8px; margin: 8px 0; }
.code { font-family: ui-monospace, Menlo, Consolas, monospace; font-weight: 600; }

.source { border-left: 4px solid var(--line); padding: 4px 12px; margin: 8px 0; }

.questions { padding-left: 1.4em; }
.question { margin: 14px 0; }
.prompt { margin: 0 0 4px; font-weight: 500; }
.option { margin: 2px 0 2px 8px; }
.hint { color: var(--muted); font-size: 0.9rem; margin: 4px 0; }
.meta { color: var(--muted); font-size: 0.8rem; margin: 2px 0; }
.key { color: var(--good); font-weight: 600; margin: 4px 0; }
.note { color: var(--muted); font-size: 0.9rem; margin: 2px 0 6px; }
.swap-note { color: var(--muted); font-style: italic; }
.mark { font-weight: 600; margin: 4px 0; }
.mark.match { color: var(--good); }
.mark.no-match { color: var(--bad); }
.summary { font-weight: 700; font-size: 1.1rem; }
.print-only { display: none; }

footer { color: var(--muted); font-size: 0.85rem; }

@media (max-width: 480px) {
  input#code-input { width: 100%; }
}

@media print {
  body { background: #fff; padding: 0; font-size: 12pt; }
  .no-print, nav, footer, header { display: none !important; }
  section { border: 0; padding: 0; margin: 0; }
  .print-only { display: block; }
  .question { break-inside: avoid; }
}