/* Palette adapted from SHA-256 Byte Inspector, MIT (c) 2026 ipusiron. */
:root {
  color-scheme: dark;
  --bg: #0d1117;
  --surface: #161d27;
  --fg: #e8eef4;
  --muted: #a7b4c2;
  --border: #7d8b9a;
  --accent: #56c8ff;
  --good: #6fd48a;
  --warn: #f2b84b;
  --focus: #ffffff;
}
:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f6f5f0;
  --surface: #eeede6;
  --fg: #1b2129;
  --muted: #505a66;
  --border: #5c6773;
  --accent: #0a6c9a;
  --good: #1f7a3a;
  --warn: #8a5200;
  --focus: #000000;
}
*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  max-width: 1080px;
  margin: auto;
  padding: 16px;
  min-height: 100dvh;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  overflow-wrap: anywhere;
}
h1 { font-size: 1.5rem; margin: 0; }
h2 { font-size: 1.25rem; margin: 0 0 1rem; }
h3 { font-size: 1.125rem; }
p { margin: 0.65rem 0; }
header { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-block: 1rem 2rem; }
header > p { flex-basis: 100%; }
.header-tools { display: flex; gap: 8px; margin-left: auto; }
main { display: grid; gap: 20px; }
.card { min-width: 0; padding: 16px; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; }
button, input, select { font: inherit; }
:where(button, select) {
  min-height: 44px;
  min-width: 44px;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 12px;
  color: var(--fg);
  background: var(--surface);
  cursor: pointer;
}
button:disabled { opacity: 0.6; cursor: default; }
.icon-button { width: 44px; height: 44px; padding: 10px; border-radius: 50%; }
.icon-button svg { display: block; width: 22px; height: 22px; }
.primary { border-color: var(--accent); color: var(--accent); font-weight: 700; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
a { color: var(--accent); display: inline-flex; align-items: center; min-height: 44px; min-width: 44px; }
input[type="range"] { display: block; width: 100%; min-height: 44px; margin: 0; accent-color: var(--accent); }
fieldset { margin: 0 0 16px; padding: 8px; border: 1px solid var(--border); border-radius: 6px; }
.choices, .actions { display: flex; flex-wrap: wrap; gap: 8px; }
.choice { display: inline-flex; align-items: center; gap: 8px; min-height: 44px; min-width: 44px; padding: 8px; }
.choice input { width: 18px; height: 18px; margin: 0; }
dl { display: grid; gap: 0; margin: 0; }
dl > div { padding-block: 8px; border-bottom: 1px solid var(--border); }
dt { color: var(--muted); }
dd { margin: 0; font-family: ui-monospace, Consolas, monospace; }
.muted { color: var(--muted); }
.warning { color: var(--warn); }
.warning:empty { display: none; }
.current-frequency { font-size: clamp(2rem, 10vw, 4rem); font-variant-numeric: tabular-nums; margin: 0.4rem 0; }
.readout { min-height: 2rem; }
.reach-row { padding: 8px 0; border-bottom: 1px solid var(--border); }
.reach-label { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; }
progress { width: 100%; height: 14px; accent-color: var(--accent); }
.status-reached { color: var(--good); }
.status-weak { color: var(--warn); }
.status-absent, .status-unavailable { color: var(--muted); }
.table-wrap { max-width: 100%; overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
th, td { padding: 8px; border: 1px solid var(--border); text-align: left; vertical-align: top; }
.results-table { min-width: 48rem; }
.results-table th:first-child { white-space: nowrap; }
.results-table th:nth-child(2), .results-table th:nth-child(3),
.results-table td:nth-child(2), .results-table td:nth-child(3) { min-width: 8rem; overflow-wrap: normal; }
.results-table td:last-child { min-width: 18rem; }
details { border-top: 1px solid var(--border); padding: 8px 0; }
summary { min-height: 44px; padding: 8px 0; cursor: pointer; font-weight: 700; }
dialog {
  max-width: min(680px, calc(100% - 24px));
  max-height: calc(100dvh - 32px);
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  color: var(--fg);
}
dialog::backdrop { background: #0009; }
.help-header {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  position: sticky; top: -20px; z-index: 1; padding-block: 12px; background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.help-header h2 { margin: 0; }
.help-header button { flex-shrink: 0; }
.help-start { margin-block: 16px 24px; padding: 16px; border: 2px solid var(--accent); border-radius: 8px; }
.help-start h3 { margin-top: 0; }
.help-flow { color: var(--accent); font-weight: 700; }
.help-start ol { margin-bottom: 0; padding-left: 1.5em; }
.help-start li + li { margin-top: 12px; }
.help-pattern { padding-block: 8px 20px; border-bottom: 1px solid var(--border); }
.help-pattern h3 { margin-top: 8px; }
.help-pattern figure { margin: 0; }
.help-diagram { display: block; width: 100%; max-width: 320px; height: auto; margin: 0 auto 12px; }
.help-diagram text { fill: currentColor; text-anchor: middle; font-size: 18px; }
.diagram-background { fill: var(--surface); }
.diagram-device { fill: none; stroke: currentColor; stroke-width: 2; }
.diagram-active { color: var(--accent); }
.diagram-other { color: var(--muted); }
footer { padding: 24px 0; text-align: center; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip-path: inset(50%); }
.lesson-figure { max-width: 100%; height: auto; color: var(--accent); }
@media (min-width: 600px) {
  .card { padding: 24px; }
  dl { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 24px; }
}
@media (hover: hover) {
  button:hover:not(:disabled), summary:hover { outline: 1px solid var(--accent); }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}