:root {
  --bg: #f7f7f8; --panel: #fff; --ink: #1a1a1c; --muted: #6b7280;
  --line: #e5e7eb; --ok: #16a34a; --warn: #d97706; --err: #dc2626;
  --accent: #2563eb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17181b; --panel: #1f2024; --ink: #e8e8ea; --muted: #9ca3af;
    --line: #303239;
  }
}
* { box-sizing: border-box; }
/* An author `display` rule beats the user agent's [hidden] rule, so the
   inactive tab's unit would otherwise stay visible. */
[hidden] { display: none !important; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 14px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
header {
  position: sticky; top: 0; z-index: 10; background: var(--panel);
  border-bottom: 1px solid var(--line); padding: 0 16px;
}
.tabs { display: flex; gap: 4px; }
.tab {
  background: none; border: none; border-bottom: 2px solid transparent;
  padding: 12px 14px; font: inherit; color: var(--muted); cursor: pointer;
  text-align: left;
}
.tab.active { color: var(--ink); border-bottom-color: var(--accent); }
.tab .serial { display: block; font-size: 11px; color: var(--muted); font-family: ui-monospace, monospace; }
.controls {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  padding: 8px 0 10px;
}
.range-buttons button, #live {
  background: var(--bg); color: var(--ink); border: 1px solid var(--line);
  border-radius: 6px; padding: 4px 10px; font: inherit; cursor: pointer;
}
.range-buttons button.active { background: var(--accent); color: #fff; border-color: var(--accent); }
#live.on { color: var(--ok); border-color: var(--ok); }
#live:not(.on) { color: var(--muted); }
.controls .user { margin-left: auto; color: var(--muted); font-size: 12px; }
.controls a { color: var(--accent); }
select { font: inherit; padding: 3px 6px; background: var(--bg); color: var(--ink);
         border: 1px solid var(--line); border-radius: 6px; }

main { padding: 16px; display: flex; flex-direction: column; gap: 16px; }
.unit { display: flex; flex-direction: column; gap: 16px; }
.dock, .logs {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 10px; padding: 14px;
}
.dock-head { display: flex; align-items: flex-start; gap: 18px; flex-wrap: wrap; margin-bottom: 10px; }
h2 { margin: 0; font-size: 15px; }
.pins { display: flex; gap: 10px; }
.pin {
  display: grid; grid-template-columns: auto; gap: 1px;
  border: 1px solid var(--line); border-left-width: 4px;
  border-radius: 8px; padding: 6px 10px; min-width: 150px;
}
.pin-name { font-family: ui-monospace, monospace; font-size: 11px; color: var(--muted); }
.pin-value { font-weight: 600; }
.pin-age { font-size: 11px; color: var(--muted); }
.pin.ok { border-left-color: var(--ok); }
.pin.stale { border-left-color: var(--warn); }
.pin.stale-charging { border-left-color: var(--accent); }
.pin.error { border-left-color: var(--err); }
.pin.unknown { border-left-color: var(--muted); }
/* A retained past reading must not look like a live one. */
.pin.historical .pin-value { font-style: italic; opacity: .75; }

.series-toggles { display: flex; gap: 12px; flex-wrap: wrap; margin-left: auto; font-size: 12px; }
.series-toggles label { display: flex; align-items: center; gap: 4px; color: var(--muted); cursor: pointer; }
.chart { width: 100%; min-height: 260px; }
.chart-empty {
  display: grid; place-items: center; min-height: 260px;
  border: 1px dashed var(--line); border-radius: 8px;
  color: var(--muted); font-size: 13px; text-align: center; padding: 12px;
}
.chart-note { margin: 6px 0 0; font-size: 11px; color: var(--muted); }

.logs-head { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; flex-wrap: wrap; }
.log-search {
  flex: 1; min-width: 240px; font: inherit; padding: 5px 9px;
  background: var(--bg); color: var(--ink);
  border: 1px solid var(--line); border-radius: 6px;
}
.log-meta { font-size: 12px; color: var(--muted); }
.log-list { max-height: 420px; overflow: auto; border-top: 1px solid var(--line); }
.log-row {
  display: grid; grid-template-columns: 96px 34px 88px 1fr; gap: 8px;
  padding: 4px 2px; border-bottom: 1px solid var(--line);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 11.5px;
}
.log-time, .log-dock, .log-kind { color: var(--muted); white-space: nowrap; }
.log-payload { overflow-wrap: anywhere; }

.login-page { display: grid; place-items: center; min-height: 100vh; }
.login {
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px;
  padding: 28px; width: min(340px, 92vw); display: flex; flex-direction: column; gap: 14px;
}
.login h1 { font-size: 17px; margin: 0 0 4px; }
.login label { display: flex; flex-direction: column; gap: 5px; font-size: 12px; color: var(--muted); }
.login input {
  font: inherit; padding: 8px 10px; border: 1px solid var(--line);
  border-radius: 6px; background: var(--bg); color: var(--ink);
}
.login button {
  font: inherit; padding: 9px; border: none; border-radius: 6px;
  background: var(--accent); color: #fff; cursor: pointer;
}
.error { color: var(--err); margin: 0; font-size: 13px; }