:root {
  --bg: #f7f7f5;
  --fg: #1d1d1f;
  --muted: #6b6b70;
  --card: #ffffff;
  --border: #d9d9de;
  --accent: #2463eb;
  --accent-fg: #ffffff;
  --error-bg: #fdecec;
  --error-fg: #9b1c1c;
  --l2: #b45309;
  --l3: #1d4ed8;
  --l7: #047857;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #161618;
    --fg: #e8e8ea;
    --muted: #9a9aa2;
    --card: #1f1f22;
    --border: #36363c;
    --accent: #5b8cff;
    --accent-fg: #0b0b0c;
    --error-bg: #3a1717;
    --error-fg: #ffb4b4;
    --l2: #f5a65b;
    --l3: #8fb0ff;
    --l7: #5fd3a6;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

header { border-bottom: 1px solid var(--border); background: var(--card); }
nav { max-width: 960px; margin: 0 auto; padding: 0.75rem 1rem; display: flex; gap: 1.25rem; flex-wrap: wrap; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover, nav a.active { color: var(--fg); }
nav a.brand { color: var(--fg); font-weight: 600; }

main { max-width: 960px; margin: 0 auto; padding: 1.5rem 1rem 3rem; }
h1 { margin: 0 0 0.5rem; font-size: 1.6rem; }
h2 { font-size: 1.25rem; margin: 0 0 0.75rem; }
h3 { font-size: 1rem; margin: 1.25rem 0 0.5rem; }
.lead { color: var(--muted); margin-top: 0; }
a { color: var(--accent); }
code { font-family: var(--mono); font-size: 0.9em; }
.hint { color: var(--muted); font-weight: normal; font-size: 0.85em; }

.tools { list-style: none; padding: 0; display: grid; gap: 0.75rem; }
.tools li { background: var(--card); border: 1px solid var(--border); border-radius: 8px; padding: 1rem; }
.tools a { font-weight: 600; font-size: 1.05rem; }
.tools p { margin: 0.25rem 0 0; color: var(--muted); }

form label { display: block; font-weight: 600; margin: 1rem 0 0.3rem; }
textarea, input, select {
  width: 100%;
  font: inherit;
  color: var(--fg);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.5rem 0.6rem;
}
textarea { font-family: var(--mono); font-size: 0.9rem; resize: vertical; }
textarea:focus, input:focus, select:focus { outline: 2px solid var(--accent); outline-offset: -1px; }

fieldset { border: 0; padding: 0; margin: 0; }
label.check { display: flex; gap: 0.5rem; align-items: baseline; flex-wrap: wrap; font-weight: 600; }
label.check input { width: auto; }
.row { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 1rem; }
@media (max-width: 720px) { .row { grid-template-columns: 1fr; gap: 0; } }

.actions { margin-top: 1.25rem; display: flex; gap: 0.75rem; }
button {
  font: inherit;
  padding: 0.5rem 1.1rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--fg);
  cursor: pointer;
}
button.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-fg); }

.error { background: var(--error-bg); color: var(--error-fg); padding: 0.75rem 1rem; border-radius: 6px; margin: 1rem 0; }
.note { color: var(--muted); margin: 0.35rem 0; }

.result { margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--border); }
.summary { display: grid; grid-template-columns: max-content 1fr; gap: 0.25rem 1rem; margin: 0; }
.summary dt { color: var(--muted); }
.summary dd { margin: 0; }

table { border-collapse: collapse; width: 100%; background: var(--card); border: 1px solid var(--border); }
th, td { text-align: left; padding: 0.4rem 0.75rem; border-bottom: 1px solid var(--border); }
th { color: var(--muted); font-weight: 600; font-size: 0.85rem; }
tr.changed td:last-child { font-weight: 600; }

.dump {
  font-family: var(--mono);
  font-size: 0.85rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.75rem 1rem;
  overflow-x: auto;
}
.dump .off { color: var(--muted); }
.l2 { color: var(--l2); }
.l3 { color: var(--l3); }
.l7 { color: var(--l7); }
.chg { text-decoration: underline; text-underline-offset: 3px; font-weight: 700; }

input[type=file] { padding: 0.4rem; }
.modes { margin-top: 1rem; }
.modes legend { font-weight: 600; margin-bottom: 0.3rem; }
.modes label.check { font-weight: normal; margin: 0.5rem 0; align-items: center; }
.modes input.num { width: 8rem; }
.modes select.unit { width: auto; }