:root {
  color-scheme: dark;
  --bg: #0b0d12;
  --panel: #151822;
  --panel-2: #1c202c;
  --text: #eef0f4;
  --muted: #8b93a7;
  --accent: #ff5470;
  --zone1: #3fb1ff;
  --zone2: #3fe0c9;
  --zone3: #ffd23f;
  --zone4: #ff9a3f;
  --zone5: #ff4f4f;
  --radius: 16px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", Segoe UI, Roboto, sans-serif;
}

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 24px 16px 60px;
}

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.top h1 {
  font-size: 20px;
  margin: 0;
  font-weight: 600;
  color: var(--muted);
}

.pill {
  font-size: 13px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--panel-2);
  color: var(--muted);
}
.pill.active { background: rgba(255, 84, 112, 0.15); color: var(--accent); }
.pill.paused { background: rgba(255, 210, 63, 0.15); color: var(--zone3); }

.hero {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 16px;
  background: var(--panel);
  border-radius: var(--radius);
  padding: 24px;
}

@media (max-width: 560px) {
  .hero { grid-template-columns: 1fr; }
}

.hr-block { text-align: center; }
.hr-value {
  font-size: 64px;
  font-weight: 700;
  line-height: 1;
}
.hr-value small {
  font-size: 18px;
  font-weight: 500;
  color: var(--muted);
  margin-left: 4px;
}
.hr-zone {
  margin-top: 8px;
  font-size: 13px;
  color: var(--muted);
}

.workout-block { display: flex; flex-direction: column; justify-content: center; gap: 16px; }
.workout-type {
  font-size: 22px;
  font-weight: 600;
  text-transform: capitalize;
}
.stat-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.stat { display: flex; flex-direction: column; }
.stat .label { font-size: 12px; color: var(--muted); }
.stat .value { font-size: 18px; font-weight: 600; }

.chart-section, .history {
  margin-top: 24px;
  background: var(--panel);
  border-radius: var(--radius);
  padding: 20px;
}
.chart-section h2, .history h2 {
  font-size: 15px;
  color: var(--muted);
  margin: 0 0 12px;
  font-weight: 600;
}

.sessions-list { display: flex; flex-direction: column; gap: 8px; }
.session-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--panel-2);
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 14px;
}
.session-row .type { text-transform: capitalize; font-weight: 600; }
.session-row .meta { color: var(--muted); font-size: 12px; }

.foot {
  margin-top: 20px;
  text-align: center;
  font-size: 12px;
  color: var(--muted);
}