:root {
  --bg: #0b0d10;
  --fg: #e6edf3;
  --muted: #8b949e;
  --accent: #7cf;
  --accent-strong: #4ac;
  --danger: #f87171;
  --ok: #34d399;
  --warn: #fbbf24;
  --card: #11151a;
  --border: #1f2833;
  --radius: 18px;
  --safe-top: env(safe-area-inset-top, 0);
  --safe-bot: env(safe-area-inset-bottom, 0);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui,
               "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  overscroll-behavior: none;
}

#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: calc(16px + var(--safe-top)) 20px calc(16px + var(--safe-bot));
  gap: 24px;
}

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-wrap {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.brand {
  font-weight: 800;
  letter-spacing: 3px;
  font-size: 18px;
  color: var(--fg);
}
.subtitle {
  font-size: 11px;
  letter-spacing: 1.5px;
  color: var(--muted);
  text-transform: uppercase;
}

.pill {
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  border: 1px solid var(--border);
  color: var(--muted);
}
.pill--idle { color: var(--muted); }
.pill--viewing { color: var(--accent); border-color: var(--accent-strong); }
.pill--tracking { color: var(--ok); border-color: #14532d; background: #052e1a; }
.pill--error { color: var(--danger); border-color: #7f1d1d; background: #2a0e0e; }

.stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  gap: 24px;
  padding: 16px 0;
}

.label {
  font-weight: 900;
  font-size: clamp(48px, 14vw, 128px);
  line-height: 1;
  letter-spacing: -0.02em;
  padding: 0 8px;
  word-break: break-word;
  transition: color 180ms ease;
}
.label--idle { color: var(--muted); }
.label--walking { color: #60a5fa; }
.label--walking_upstairs { color: #a78bfa; }
.label--walking_downstairs { color: #f472b6; }
.label--sitting { color: #34d399; }
.label--standing { color: #fbbf24; }
.label--laying { color: #22d3ee; }
.label--stationary { color: #34d399; }
.label--moving { color: #60a5fa; }

.confidence {
  width: min(520px, 100%);
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "bar bar"
    "txt txt";
  gap: 8px;
  align-items: center;
}
.confidence__bar {
  grid-area: bar;
  height: 10px;
  background: var(--card);
  border-radius: 999px;
  overflow: hidden;
  position: relative;
  border: 1px solid var(--border);
}
.confidence__bar::after {
  content: "";
  position: absolute;
  inset: 0;
  width: var(--w, 0%);
  background: linear-gradient(90deg, var(--accent-strong), var(--accent));
  transition: width 220ms ease;
}
.confidence__text {
  grid-area: txt;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
  font-size: 13px;
  letter-spacing: 0.5px;
}

.source {
  color: var(--muted);
  font-size: 13px;
  letter-spacing: 0.5px;
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: stretch;
}

.btn {
  font: inherit;
  padding: 18px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--fg);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.3px;
  cursor: pointer;
  transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
}
.btn:active { transform: scale(0.98); }
.btn--primary {
  background: var(--accent);
  color: #001018;
  border-color: var(--accent);
}
.btn--ghost {
  background: transparent;
}

.hidden { display: none !important; }

.msg {
  color: var(--muted);
  font-size: 13px;
  min-height: 18px;
  text-align: center;
}
.msg--err { color: var(--danger); }
.msg--warn { color: var(--warn); }
.msg--ok { color: var(--ok); }

.bottom {
  color: var(--muted);
  font-size: 12px;
  text-align: center;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.5px;
  min-height: 16px;
}

.about {
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px 14px 12px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 10px;
}
.about__title {
  color: var(--fg);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.2px;
  line-height: 1.35;
}
.about__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.chip {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.3px;
  padding: 5px 9px;
  border-radius: 999px;
  background: #0b1018;
  border: 1px solid var(--border);
  color: var(--fg);
}
.about__more summary {
  cursor: pointer;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  user-select: none;
  padding: 4px 0;
}
.about__grid {
  margin: 8px 0 0;
  display: grid;
  grid-template-columns: max-content 1fr;
  column-gap: 14px;
  row-gap: 6px;
  font-size: 12px;
  line-height: 1.4;
}
.about__grid dt {
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  font-size: 10px;
  padding-top: 2px;
}
.about__grid dd {
  margin: 0;
  color: var(--fg);
}
.link {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px dashed var(--accent-strong);
}
.link:hover { color: var(--fg); border-bottom-color: var(--fg); }

.debug {
  margin-top: 10px;
  text-align: left;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 8px 12px;
}
.debug summary {
  cursor: pointer;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
  user-select: none;
}
.debug__body {
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 12px;
  color: var(--fg);
}
.debug__row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}
.debug__row span:first-child { color: var(--muted); }
.debug__probs {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2px 12px;
  margin-top: 4px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

@media (prefers-reduced-motion: reduce) {
  .confidence__bar::after, .label { transition: none; }
}