:root {
  color-scheme: light dark;
  --bg: #c9cec2;          /* console panel grey-green */
  --panel: #dfe3d8;
  --ink: #1f2a2e;         /* graphite */
  --ink-soft: #47524f;
  --rule: #9aa294;        /* decorative lines only */
  --edge: #666f64;        /* control borders: 3:1 against bg, panel and cell */
  --pencil: #9a2b23;      /* red pencil: unknown characters */
  --signal: #c98a00;      /* squelch lamp */
  --cell: #f2f4ee;
  --focus: #1e5aa8;
  --crowd: #24539a;       /* blue pencil: listeners' corrections */
  --ok: #285d32;
  --tile-filter: none;
  --ui: "Archivo", system-ui, sans-serif;
  --copy: "Martian Mono", ui-monospace, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #1a201d; --panel: #232b27; --ink: #d6ddd2; --ink-soft: #95a198;
    --rule: #3c4741; --edge: #76837b; --pencil: #ec8a80; --signal: #e8b030; --cell: #2b342f; --focus: #7fb0f0;
    --crowd: #8db4ee; --ok: #7cc48a; --tile-filter: invert(1) hue-rotate(180deg) brightness(.85) contrast(.9);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #1a201d; --panel: #232b27; --ink: #d6ddd2; --ink-soft: #95a198;
  --rule: #3c4741; --edge: #76837b; --pencil: #ec8a80; --signal: #e8b030; --cell: #2b342f; --focus: #7fb0f0;
    --crowd: #8db4ee; --ok: #7cc48a; --tile-filter: invert(1) hue-rotate(180deg) brightness(.85) contrast(.9);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 400 16px/1.5 var(--ui); font-variation-settings: "wdth" 100;
}
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip {
  position: absolute; left: 12px; top: -60px; z-index: 1001; padding: 8px 14px;
  background: var(--ink); color: var(--bg); border-radius: 4px; font-weight: 650;
}
.skip:focus { top: 12px; }
main:focus { outline: none; }

/* --- top bar --- */
.bar {
  display: grid; grid-template-columns: auto 1fr; gap: 6px 24px; align-items: center;
  padding: 14px clamp(16px, 4vw, 40px); border-bottom: 2px solid var(--ink);
}
.mark {
  margin: 0; font-size: 22px; font-weight: 800; font-variation-settings: "wdth" 125;
  letter-spacing: -0.01em;
}
.brand { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.tag { margin: 0; font-size: 13px; color: var(--ink-soft); }
.tuner { display: flex; align-items: center; gap: 16px; justify-self: end; flex-wrap: wrap; }
.src { grid-column: 1 / -1; margin: 0; font-size: 13px; color: var(--ink-soft); }
.listen {
  display: inline-flex; align-items: center; gap: 10px; padding: 8px 16px;
  border: 2px solid var(--ink); border-radius: 999px; background: transparent;
  font-weight: 650; cursor: pointer;
}
.listen.on { background: var(--ink); color: var(--bg); }
.listen-icon {
  width: 0; height: 0; border-left: 10px solid currentColor;
  border-top: 6px solid transparent; border-bottom: 6px solid transparent;
}
.listen.on .listen-icon {
  width: 10px; height: 12px; border: 0;
  border-left: 3px solid currentColor; border-right: 3px solid currentColor;
}
.dial { display: flex; align-items: baseline; gap: 6px; }
.freq {
  font-size: 30px; font-weight: 750; font-variation-settings: "wdth" 75;
  font-variant-numeric: tabular-nums; line-height: 1;
}
.unit { font-size: 13px; color: var(--ink-soft); }
.meter {
  position: relative; width: 120px; height: 8px; background: var(--panel);
  border: 1px solid var(--edge); border-radius: 4px; overflow: hidden;
}
.meter-fill { height: 100%; width: 0; background: var(--ink); transition: width .25s linear; }
.meter-thresh { position: absolute; top: -1px; bottom: -1px; width: 3px; background: var(--signal); box-shadow: 0 0 0 1px var(--ink); }
.sql {
  min-width: 82px; padding: 3px 10px; border-radius: 4px; font-size: 13px; font-weight: 650;
  text-align: center; border: 1px solid var(--edge); color: var(--ink-soft);
}
.sql.open { background: var(--signal); border-color: var(--signal); color: #1b1600; }
.sql.down { color: var(--pencil); border-color: var(--pencil); }
.sql.ended { color: var(--ink-soft); border-style: dashed; }
.notify {
  display: inline-flex; align-items: center; gap: 6px; padding: 4px 12px;
  border: 1.5px solid var(--ink); border-radius: 999px; background: transparent;
  font-size: 14px; font-weight: 600; cursor: pointer;
}
.notify[aria-pressed="true"] { background: var(--signal); border-color: var(--signal); color: #1b1600; }

.toast {
  position: fixed; left: 50%; bottom: 20px; transform: translateX(-50%); z-index: 1000;
  width: max-content; max-width: min(520px, calc(100vw - 32px));
  padding: 12px 16px; border-radius: 6px; background: var(--ink); color: var(--bg);
  font-size: 15px; box-shadow: 0 6px 24px rgb(0 0 0 / .25);
}

main { max-width: 1120px; margin: 0 auto; padding: 0 clamp(16px, 4vw, 40px); }

/* --- section tabs --- */
.views {
  display: flex; gap: 4px; padding: 0 clamp(16px, 4vw, 40px);
  border-bottom: 1px solid var(--rule); overflow-x: auto;
}
.views a {
  padding: 10px 14px 9px; color: var(--ink-soft); text-decoration: none; font-weight: 600;
  border-bottom: 3px solid transparent; white-space: nowrap;
}
.views a:hover { color: var(--ink); }
.views a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--ink); }

.page { padding: 32px 0 48px; }
.page h2 { margin: 0 0 8px; font-size: clamp(26px, 4vw, 36px); font-weight: 750; font-variation-settings: "wdth" 85; }
.lede { max-width: 68ch; color: var(--ink-soft); margin: 0 0 16px; }

.btn {
  padding: 7px 14px; border: 1.5px solid var(--ink); background: transparent; border-radius: 4px;
  cursor: pointer; font-weight: 600; font-size: 15px;
}
.btn.primary { background: var(--ink); color: var(--bg); }
.btn.small { min-width: 36px; min-height: 36px; padding: 2px 10px; font: 600 15px/1.4 var(--copy); }
.btn:disabled { opacity: .45; cursor: not-allowed; }

/* --- first-visit intro and about page --- */
.intro {
  margin-top: 24px; padding: 16px 20px; max-width: 75ch;
  background: var(--panel); border: 1px solid var(--edge); border-radius: 6px;
}
.intro h2 { margin: 0 0 6px; font-size: 18px; font-weight: 750; }
.intro p { margin: 0 0 10px; }
.intro-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 20px; margin: 4px 0 0 !important; }
.intro a, .about a { color: inherit; text-decoration: underline; text-underline-offset: 2px; }
.about { max-width: 75ch; }
.about h3 { margin: 28px 0 6px; font-size: 19px; font-weight: 700; }
.about p { margin: 0 0 12px; }
.guide { margin: 8px 0 0; display: grid; gap: 12px; }
.guide dt { font-weight: 700; }
.guide dd { margin: 2px 0 0; color: var(--ink-soft); }
abbr[title] { text-decoration: underline dotted; cursor: help; }
/* external links open in a new tab; the arrow is decorative (the link text says so to screen readers) */
a[target="_blank"]::after { content: "\2197" / ""; margin-left: 2px; font-size: 0.85em; }

/* --- copy pad (the hero) --- */
.pad { padding: 36px 0 28px; border-bottom: 1px solid var(--rule); }
.pad-empty p { max-width: 52ch; color: var(--ink-soft); font-size: 18px; margin: 0; }
.pad-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 20px; }
.pad-head h2 {
  margin: 0; font-size: clamp(26px, 4vw, 40px); font-weight: 750; line-height: 1.1;
  font-variation-settings: "wdth" 85; font-variant-numeric: tabular-nums;
}
.pad-meta { margin: 0; color: var(--ink-soft); }
#player { width: 100%; max-width: 560px; margin: 18px 0 8px; }

.copy-block { margin-top: 22px; }
.copy-block h3 { margin: 0 0 8px; font-size: 14px; font-weight: 650; color: var(--ink-soft); }
.cells { display: flex; flex-wrap: wrap; gap: 6px; }
.cell {
  position: relative; width: clamp(30px, 6.6vw, 44px); aspect-ratio: 4 / 5;
  display: grid; place-items: center; padding: 0;
  background: var(--cell); border: 1.5px solid var(--ink); border-radius: 3px;
  font: 600 clamp(16px, 3.4vw, 24px)/1 var(--copy); cursor: pointer;
}
.cell::after {           /* position number, like a printed copy sheet */
  content: attr(data-n); position: absolute; top: 2px; left: 3px;
  font: 400 8px/1 var(--ui); color: var(--ink-soft);
}
.cell.unk { color: var(--pencil); border-color: var(--pencil); border-style: dashed; }
.cell.crowd { color: var(--crowd); border-color: var(--crowd); text-decoration: underline; text-underline-offset: 3px; }
.cell.voted { box-shadow: inset 0 -3px 0 var(--crowd); }
.cell.picked { outline: 3px solid var(--focus); outline-offset: 2px; }
.cell.playing { background: var(--signal); color: #1b1600; }
.cell.static { cursor: default; }
.cells.small .cell { width: clamp(20px, 4vw, 26px); font-size: clamp(11px, 2.2vw, 14px); border-width: 1px; }
.cells.small .cell::after { content: none; }
.copies { display: grid; gap: 10px; margin-top: 14px; }
.copies .lbl { font-size: 12px; color: var(--ink-soft); margin-bottom: 4px; }
.alts { font-size: 13px; color: var(--ink-soft); margin: 10px 0 0; }

/* --- correction editor --- */
.fix { margin-top: 16px; padding: 14px 16px; background: var(--panel); border: 1px solid var(--rule); border-radius: 6px; max-width: 640px; }
.fix-head { margin: 0; font-weight: 700; }
.fix-info { margin: 4px 0 10px; display: grid; gap: 2px; font-size: 14px; color: var(--ink-soft); }
.fix-form { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.fix-form label { font-size: 14px; }
#fix-char {
  width: 44px; height: 44px; text-align: center; text-transform: uppercase;
  font: 600 22px/1 var(--copy); color: var(--ink); background: var(--cell);
  border: 1.5px solid var(--ink); border-radius: 3px;
}
.fix-quick { display: inline-flex; gap: 6px; }
.fix-note { margin: 10px 0 0; font-size: 13px; color: var(--ink-soft); }

/* --- copy trainer --- */
.tr-controls { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 20px; margin: 12px 0 18px; }
.tr-controls audio { width: 100%; max-width: 480px; }
.tr-rate { font-size: 14px; color: var(--ink-soft); }
.tr-rate select { font: inherit; color: var(--ink); background: var(--cell); border: 1px solid var(--edge); border-radius: 4px; padding: 3px 6px; margin-left: 4px; }
.tr-cell { cursor: text; }
.tr-cell:focus-within { outline: 2px solid var(--focus); outline-offset: 2px; }
.tr-cell input {
  all: unset; width: 100%; height: 100%; text-align: center; text-transform: uppercase;
  font: inherit; color: inherit;
}
.tr-cell.ok { border-color: var(--ok); color: var(--ok); }
.tr-cell.bad, .tr-cell.miss { border-color: var(--pencil); color: var(--pencil); }
.tr-cell.miss { border-style: dashed; }
.tr-cell.nokey { border-style: dotted; color: var(--ink-soft); }
.tr-cell[data-ref]::before {     /* the right answer, tucked under a wrong cell */
  content: attr(data-ref); position: absolute; bottom: -18px; left: 0; right: 0;
  font: 600 12px/1 var(--copy); color: var(--ok); text-align: center;
}
#tr-grid { row-gap: 22px; }
.tr-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 26px; }
.tr-score { font-weight: 650; margin: 16px 0 0; min-height: 1.5em; }
.tr-share { margin-top: 16px; padding: 12px 16px; background: var(--panel); border: 1px solid var(--rule); border-radius: 6px; max-width: 640px; }
.tr-share p { margin: 0 0 8px; }

/* --- aircraft --- */
.map {
  height: min(60vh, 520px); margin-top: 8px; border: 1.5px solid var(--ink); border-radius: 4px;
  background: var(--panel); color: var(--ink-soft); display: grid; place-items: center;
}
.map.leaflet-container { display: block; font: inherit; }
.map .leaflet-tile-pane { filter: var(--tile-filter); }
.ac { background: none; border: 0; }
.ac-tip { font: 600 12px/1 var(--ui); padding: 2px 5px; }
.air-rows tbody tr[data-hex] { cursor: pointer; }

.sky { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 16px; margin-top: 22px; }
.sky div { border-top: 2px solid var(--ink); padding-top: 6px; }
.sky dt { font-size: 13px; color: var(--ink-soft); }
.sky dd { margin: 0; font: 600 22px/1.3 var(--copy); }

.transcript { margin-top: 22px; max-width: 75ch; }
.transcript summary { cursor: pointer; color: var(--ink-soft); font-size: 14px; }
.transcript p { font-size: 15px; }
.lowp { text-decoration: underline wavy var(--pencil); text-underline-offset: 3px; }

/* --- log --- */
.log { padding: 28px 0 48px; }
.log-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.log-head h2 { margin: 0; font-size: 22px; font-weight: 750; }
.filters { display: flex; gap: 4px; }
.filters button {
  padding: 5px 12px; border: 1px solid var(--edge); background: transparent;
  border-radius: 4px; cursor: pointer; font-size: 14px;
}
.filters button[aria-pressed="true"] { background: var(--ink); border-color: var(--ink); color: var(--bg); }
.rows { width: 100%; border-collapse: collapse; margin-top: 16px; }
.rows th {
  text-align: left; font-size: 13px; font-weight: 600; color: var(--ink-soft);
  padding: 6px 10px 6px 0; border-bottom: 2px solid var(--ink);
}
.rows td { padding: 10px 10px 10px 0; border-bottom: 1px solid var(--rule); vertical-align: baseline; }
.rows tbody tr { cursor: pointer; }
.rowbtn {                 /* the row's keyboard/screen-reader target; the whole row is clickable too */
  padding: 0; border: 0; background: none; font: inherit; color: inherit;
  text-align: left; cursor: pointer;
}
.rows tbody tr:hover, .rows tbody tr.sel { background: var(--panel); }
.rows .num { text-align: right; font-variant-numeric: tabular-nums; }
.t { font-variant-numeric: tabular-nums; white-space: nowrap; }
.code { font: 400 15px/1.4 var(--copy); letter-spacing: 0.04em; word-break: break-all; }
.code .q { color: var(--pencil); font-weight: 600; }
.code .cr { color: var(--crowd); font-weight: 600; text-decoration: underline; text-underline-offset: 3px; }
.kind { font-size: 12px; color: var(--ink-soft); margin-right: 6px; }
.new td { animation: flash 2.4s ease-out; }
@keyframes flash { from { background: var(--signal); } to { background: transparent; } }
.more { margin-top: 16px; padding: 8px 14px; border: 1px solid var(--ink); background: transparent; border-radius: 4px; cursor: pointer; }
.empty-row td { color: var(--ink-soft); padding: 18px 0; cursor: default; }

.foot { border-top: 1px solid var(--rule); padding: 18px clamp(16px, 4vw, 40px) 32px; font-size: 13px; color: var(--ink-soft); }
.foot p { max-width: 75ch; margin: 0 auto; text-align: center; }

@media (max-width: 720px) {
  .bar { grid-template-columns: 1fr; }
  .tuner { justify-self: start; }
  .rows thead {             /* hidden on screen, still read as column headers */
    position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0);
  }
  .air-rows td[data-label]::before { content: attr(data-label) " "; color: var(--ink-soft); font: 400 13px/1.4 var(--ui); letter-spacing: 0; }
  .map { height: 45vh; }
  .rows tr { display: grid; grid-template-columns: 1fr auto auto; gap: 2px 12px; padding: 10px 0; border-bottom: 1px solid var(--rule); }
  .rows td { border: 0; padding: 0; }
  .rows td.code { grid-column: 1 / -1; grid-row: 2; }
  .air-rows tr { grid-template-columns: 1fr auto; }
  .air-rows td.code { grid-column: auto; grid-row: auto; }
  .cell::after { content: none; }
}
@media (max-width: 380px) {
  .views { gap: 0; }
  .views a { padding-inline: 10px; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}