:root {
    --bg: #f6f7f9;
    --panel: #ffffff;
    --text: #1b1f24;
    --muted: #5b6470;
    --line: #d8dde3;
    --accent: #1f6feb;
    --accent-text: #ffffff;
    --to-me-bg: #fff1c2;
    --to-me-edge: #c98a00;
    --cq-bg: #eaf4ea;
    --slot-bg: #eef1f5;
    --bar-bg: #dfe4ea;
    --bar-fill: #1f6feb;
    --bar-decode: #c98a00;
    --focus: #1f6feb;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg: #0f1216;
        --panel: #171b21;
        --text: #e6e9ee;
        --muted: #9aa4b1;
        --line: #2a313a;
        --accent: #4c8dff;
        --accent-text: #0b0e12;
        --to-me-bg: #4a3a0a;
        --to-me-edge: #f0b429;
        --cq-bg: #16301c;
        --slot-bg: #1d232b;
        --bar-bg: #2a313a;
        --bar-fill: #4c8dff;
        --bar-decode: #f0b429;
        --focus: #8ab4ff;
    }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font: 15px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.top {
    position: sticky; top: 0; z-index: 2;
    display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 16px;
    padding: 8px 16px;
    background: var(--panel);
    border-bottom: 1px solid var(--line);
}
.title { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
h1 { font-size: 20px; margin: 0; }
.stage { color: var(--muted); font-size: 13px; }
.back { font-size: 13px; color: var(--accent); }

.clock { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.utc { font: 600 22px/1 ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-variant-numeric: tabular-nums; }
.slot { display: flex; align-items: center; gap: 8px; }
.slot-bar { position: relative; width: 150px; height: 10px; background: var(--bar-bg); border-radius: 5px; overflow: hidden; }
.slot-fill { height: 100%; width: 0; background: var(--bar-fill); }
.slot-decode { position: absolute; top: 0; bottom: 0; width: 2px; background: var(--bar-decode); }
.slot-label, .clock-offset { font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }

main { max-width: 1100px; margin: 0 auto; padding: 12px 16px 40px; }
section, details { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 12px 14px; margin-bottom: 12px; }
h2 { font-size: 15px; margin: 0 0 6px; }
.help, .caption { color: var(--muted); font-size: 13px; margin: 6px 0 0; }
.caption { margin: 0 0 8px; }

.rx-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.rx-status { margin-top: 8px; }
.source-label { font-size: 13px; color: var(--muted); }
.source { display: inline-flex; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.source label { display: flex; align-items: center; gap: 6px; padding: 8px 12px; cursor: pointer; min-height: 40px; }
.source label + label { border-left: 1px solid var(--line); }
.source label:has(input:checked) { background: var(--accent); color: var(--accent-text); }
.source label.unavailable { opacity: 0.5; cursor: not-allowed; }
/* The filled button shows the choice, so the radio circles are hidden (but still focusable). */
.source input { position: absolute; opacity: 0; width: 1px; height: 1px; margin: 0; }
.source label:has(input:focus-visible) { outline: 2px solid var(--focus); outline-offset: -2px; }
button, select, input:not([type="radio"]) {
    font: inherit; color: var(--text); background: var(--panel);
    border: 1px solid var(--line); border-radius: 6px; padding: 8px 12px; min-height: 40px;
}
button { cursor: pointer; }
button.primary { background: var(--accent); color: var(--accent-text); border-color: var(--accent); font-weight: 600; }
button:disabled { opacity: 0.5; cursor: default; }
.rx-state { font-weight: 600; }
.rx-state.running::before { content: "● "; color: #2ea043; }
.rx-state.error { color: #d1242f; }
.level { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 13px; }
.level meter { width: 120px; }

.wf-frame { position: relative; }
.waterfall canvas { display: block; width: 100%; height: 300px; border-radius: 4px; background: #080a1e; cursor: crosshair; touch-action: none; }
.wf-controls { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin-top: 2px; }
.wf-controls button { min-width: 40px; padding: 4px 10px; min-height: 34px; }
.wf-readout { margin-left: 6px; font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }
.wf-axis { position: relative; height: 20px; font-size: 12px; color: var(--muted); }
.wf-tick { position: absolute; transform: translateX(-50%); white-space: nowrap; top: 2px; }
.wf-tick.wf-tick-end { transform: translateX(-100%); }
.wf-tick.wf-tick-end::before { left: 100%; }
.wf-tick.wf-tick-start { transform: none; }
.wf-tick.wf-tick-start::before { left: 0; }
.wf-tick::before { content: ""; position: absolute; left: 50%; top: -4px; height: 4px; border-left: 1px solid var(--muted); }

.band-activity table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
.band-activity th, .band-activity td { text-align: right; padding: 3px 8px; white-space: nowrap; width: 1%; }
.band-activity .ba-msg { text-align: left; width: auto; font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; white-space: normal; overflow-wrap: anywhere; }
.band-activity thead th { color: var(--muted); font-weight: 600; font-size: 13px; border-bottom: 1px solid var(--line); }
.ba-slot th { text-align: left; background: var(--slot-bg); color: var(--muted); font-weight: 600; font-size: 13px; padding-top: 5px; padding-bottom: 5px; }
.ba-to-me td { background: var(--to-me-bg); font-weight: 600; }
.ba-to-me td:first-child { box-shadow: inset 4px 0 0 var(--to-me-edge); }
.ba-cq td { background: var(--cq-bg); }
.ba-tag { margin-left: 8px; font: 600 11px system-ui, sans-serif; padding: 1px 6px; border-radius: 9px; background: var(--to-me-edge); color: #000; vertical-align: 1px; }
.ba-none { color: var(--muted); text-align: left !important; }
.ba-empty { color: var(--muted); }
.band-activity tbody tr:not(.ba-slot):hover td { outline: 1px solid var(--line); }

.station summary { cursor: pointer; font-weight: 600; }
.station-fields { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 10px; }
.station-fields label { display: flex; flex-direction: column; gap: 4px; font-size: 13px; color: var(--muted); }
.station-fields input { text-transform: uppercase; width: 12em; }

@media (max-width: 640px) {
    .top { padding: 6px 12px; }
    main { padding: 8px 8px 32px; }
    .stage { display: none; }
    .slot-bar { width: 90px; }
    .waterfall canvas { height: 200px; }
    /* UTC is in each slot's header row, and DT matters less on a small screen. */
    .band-activity thead th:nth-child(1), .band-activity tbody td:nth-child(1),
    .band-activity thead th:nth-child(3), .band-activity tbody td:nth-child(3) { display: none; }
    .band-activity tbody td.ba-none { display: table-cell; }
    .band-activity th, .band-activity td { padding: 3px 5px; }
    .source label { padding: 8px 10px; }
}

/* Transmit */
.tx-banner {
    flex-basis: 100%; display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
    background: #b42318; color: #fff; padding: 8px 12px; border-radius: 6px; font-size: 16px;
}
.tx-banner strong { text-transform: uppercase; letter-spacing: 0.05em; }
button.halt { background: #b42318; color: #fff; border-color: #b42318; font-weight: 700; }
.tx-banner button.halt { background: #fff; color: #b42318; border-color: #fff; }
.columns { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 12px; align-items: start; }
.columns > section { margin-bottom: 12px; }
@media (max-width: 900px) { .columns { grid-template-columns: 1fr; } .columns .qso { order: -1; } }
.qso-state { font-weight: 600; margin: 0 0 8px; }
.qso-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 10px; }
.tx-messages { list-style: none; margin: 0 0 10px; padding: 0; border: 1px solid var(--line); border-radius: 6px; }
.tx-messages li { display: flex; gap: 8px; align-items: center; padding: 6px 8px; cursor: pointer; font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; }
.tx-messages li + li { border-top: 1px solid var(--line); }
.tx-messages li .tx-key { color: var(--muted); font: 600 12px system-ui, sans-serif; width: 2.4em; }
.tx-messages li.next { background: var(--to-me-bg); }
.tx-messages li.next::after { content: "Next"; margin-left: auto; font: 600 11px system-ui, sans-serif; padding: 1px 6px; border-radius: 9px; background: var(--to-me-edge); color: #000; }
.tx-messages li.sending::after { content: "Sending"; background: #b42318; color: #fff; }
.tx-settings { display: grid; gap: 8px; }
.tx-settings label { display: flex; justify-content: space-between; align-items: center; gap: 8px; font-size: 14px; }
.tx-settings label.tx-enable { justify-content: flex-start; font-weight: 600; font-size: 15px; }
.tx-settings input[type="number"] { width: 6em; }
.tx-blocker { margin: 0; color: #b42318; font-size: 13px; }
.tx-blocker:empty { display: none; }
.band-activity tbody tr.ba-selected td { outline: 2px solid var(--accent); outline-offset: -2px; }
.log table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
.log th, .log td { text-align: left; padding: 3px 8px; border-bottom: 1px solid var(--line); }

/* Radio control */
.radio summary { cursor: pointer; font-weight: 600; }
.radio-fields { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 10px; }
.radio-fields label { display: flex; align-items: center; gap: 6px; font-size: 14px; }
.radio-freq { font-variant-numeric: tabular-nums; color: var(--muted); }