:root {
  --bg: #0a0e14;
  --bg-panel: #10151d;
  --border: #1e2733;
  --text: #e7ecf3;
  --text-dim: #7c8a9e;
  --accent: #ff7a1a;
  --accent-2: #16c79a;
  --accent-glow: rgba(255, 122, 26, 0.35);
  --danger: #ff4d4d;
  --radius: 14px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "Segoe UI", -apple-system, BlinkMacSystemFont, sans-serif;
  min-height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  gap: 10px;
}

.brand {
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.brand-mark { color: var(--accent); }
.brand-mark-alt { color: var(--text); }
.brand-sub {
  font-weight: 500;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-left: 4px;
}

.topbar-meta {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.pill {
  font-size: 0.78rem;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  color: var(--text);
  white-space: nowrap;
}

.pill-dim { color: var(--text-dim); }

.stage {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 20px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.gauge-wrap {
  position: relative;
  width: 360px;
  max-width: 100%;
}

/* JS owns the backing-store size (scaled by devicePixelRatio) and sets an
   explicit inline height, so only the CSS width is declared here. */
#gauge { width: 100%; display: block; }

.gauge-readout {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 22px;
  text-align: center;
  pointer-events: none;
}

.gauge-value {
  font-size: 2.6rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  line-height: 1;
}

.gauge-unit {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-top: 2px;
}

.gauge-phase {
  margin-top: 6px;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  font-weight: 700;
}

.start-btn {
  margin-top: 8px;
  padding: 14px 44px;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: #0a0e14;
  background: var(--accent);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: 0 0 0 0 var(--accent-glow);
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.start-btn:hover { transform: translateY(-1px); box-shadow: 0 6px 24px var(--accent-glow); }
.start-btn:active { transform: translateY(0); }
.start-btn:disabled {
  background: #3a3f47;
  color: var(--text-dim);
  cursor: default;
  transform: none;
  box-shadow: none;
}

.metrics {
  margin-top: 34px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  width: 100%;
}

.metric {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 10px;
  text-align: center;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.metric.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent-glow);
}

.metric-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin-bottom: 6px;
}

.metric-value {
  font-size: 1.4rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.metric-unit {
  font-size: 0.7rem;
  color: var(--text-dim);
  margin-left: 4px;
  font-weight: 500;
}

.spark {
  width: 100%;
  max-width: 900px;
  height: 90px;
  margin-top: 28px;
  display: block;
}

.footer {
  text-align: center;
  padding: 24px 16px 32px;
  color: var(--text-dim);
  font-size: 0.8rem;
}

.footer a {
  color: var(--accent-2);
  text-decoration: none;
}

.footer a:hover { text-decoration: underline; }

@media (max-width: 480px) {
  .metrics { grid-template-columns: repeat(2, 1fr); }
  .gauge-value { font-size: 2.1rem; }
  .start-btn { padding: 12px 34px; }
}