:root {
  color-scheme: light dark;
  --fg: #1a1a1a;
  --bg: #ffffff;
  --muted: #5a5a5a;
  --border: #d8d8d8;
  --accent: #1a4fd6;
  --fail: #b3261e;
  --ok: #1e7d34;
  --code-bg: #f4f4f4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fg: #e8e8e8;
    --bg: #121212;
    --muted: #a0a0a0;
    --border: #3a3a3a;
    --accent: #7fa5ff;
    --fail: #ff6b60;
    --ok: #57c76a;
    --code-bg: #1c1c1c;
  }
}

* { box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
  margin: 0;
  line-height: 1.5;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.5rem 1rem 4rem;
}

h1 {
  font-size: 1.4rem;
  margin: 0 0 0.25rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

h2 {
  font-size: 1.05rem;
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
  margin-top: 2rem;
}

h3 { font-size: 0.95rem; }

.context {
  color: var(--muted);
  font-size: 0.92rem;
  max-width: 60ch;
}

button {
  font: inherit;
  padding: 0.55rem 1rem;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--fg);
  border-radius: 4px;
  cursor: pointer;
}

button:hover { border-color: var(--accent); }

#start-btn {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  font-weight: 600;
}

.qr-row {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
  align-items: flex-start;
  margin: 1rem 0;
}

#qr-image {
  width: 180px;
  height: 180px;
  border: 1px solid var(--border);
  image-rendering: pixelated;
}

.qr-side { font-size: 0.9rem; max-width: 32ch; }

.status-track {
  display: flex;
  list-style: none;
  padding: 0;
  gap: 0.5rem;
  margin: 1.5rem 0;
  flex-wrap: wrap;
}

.status-track li {
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.82rem;
  color: var(--muted);
}

.status-track li.active {
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

.status-track li.done {
  border-color: var(--ok);
  color: var(--ok);
}

table { border-collapse: collapse; width: 100%; font-size: 0.9rem; }
table td { padding: 0.3rem 0.5rem; border-bottom: 1px solid var(--border); vertical-align: top; }
table td:first-child { color: var(--muted); white-space: nowrap; padding-right: 1rem; }

pre {
  background: var(--code-bg);
  padding: 0.75rem;
  overflow-x: auto;
  font-size: 0.78rem;
  border-radius: 4px;
  border: 1px solid var(--border);
}

.card {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.9rem 1rem;
  margin: 0.75rem 0;
}

.card-fail { border-color: var(--fail); }
.card-fail h3, #error-text { color: var(--fail); }

.sim-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.6rem;
  margin: 1rem 0;
}

.sim-result {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.9rem 1rem;
  margin-top: 0.75rem;
  font-size: 0.88rem;
}

.sim-result.expected { border-left: 4px solid var(--ok); }
.sim-result.unexpected { border-left: 4px solid var(--fail); }

.sim-result dl { margin: 0.4rem 0 0; }
.sim-result dt { color: var(--muted); font-size: 0.78rem; margin-top: 0.4rem; }
.sim-result dd { margin: 0.1rem 0 0; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.82rem; word-break: break-word; }

footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--muted);
}

a { color: var(--accent); }

@media (max-width: 400px) {
  main { padding: 1rem 0.75rem 3rem; }
  .qr-row { flex-direction: column; }
}