:root {
    --bg: #0f1117;
    --surface: #1a1d27;
    --surface2: #222535;
    --border: rgba(255,255,255,0.08);
    --border2: rgba(255,255,255,0.14);
    --text: #e8eaf0;
    --muted: #8a8fa8;
    --accent: #5b8def;
    --accent2: #3dd6a0;
    --warn: #f0a04b;
    --danger: #e05c5c;
    --ctl: #5b8def;
    --atl: #e05c5c;
    --tsb: #3dd6a0;
    --hrv: #c57bee;
    --sleep: #5b8def;
    --weight: #f0a04b;
    --radius: 12px;
    --radius-sm: 8px;
  }

  * { box-sizing: border-box; margin: 0; padding: 0; }

  body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.5;
  }

  /* Typography */
  h1 { font-size: 1.5rem; font-weight: 700; letter-spacing: -0.02em; }
  h2 { font-size: 1rem; font-weight: 600; letter-spacing: -0.01em; }
  h3 { font-size: 0.85rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); }

  /* Layout */
  header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 2rem;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
    position: sticky;
    top: 0;
    z-index: 100;
  }

  .logo {
    display: flex;
    align-items: center;
    gap: 10px;
  }

  .logo-mark {
    width: 32px; height: 32px;
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
    font-size: 16px; font-weight: 800; color: #fff;
  }

  .header-actions { display: flex; gap: 10px; align-items: center; }

  .btn {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border2);
    background: var(--surface2);
    color: var(--text);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
  }

  .btn:hover { background: var(--border2); border-color: rgba(255,255,255,0.22); }

  .btn-primary {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
  }
  .btn-primary:hover { background: #4a7de0; border-color: #4a7de0; }

  main {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
  }

  /* Setup panel */
  #setup-panel {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 60vh;
    gap: 2rem;
  }

  .setup-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem;
    width: 100%;
    max-width: 480px;
  }

  .setup-card h2 { margin-bottom: 0.4rem; font-size: 1.25rem; }
  .setup-card p { color: var(--muted); font-size: 0.875rem; margin-bottom: 1.75rem; }

  .field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 1.25rem; }
  .field label { font-size: 0.8rem; font-weight: 600; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; }
  .field input {
    padding: 0.65rem 0.9rem;
    background: var(--bg);
    border: 1px solid var(--border2);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 0.9rem;
    transition: border-color 0.15s;
  }
  .field input:focus { outline: none; border-color: var(--accent); }
  .field input::placeholder { color: var(--muted); }

  .help-text {
    font-size: 0.78rem;
    color: var(--muted);
    background: rgba(91,141,239,0.08);
    border: 1px solid rgba(91,141,239,0.18);
    border-radius: var(--radius-sm);
    padding: 0.9rem 1rem;
    margin-bottom: 1.5rem;
    line-height: 1.55;
  }

  .help-text a { color: var(--accent); text-decoration: none; }
  .help-text a:hover { text-decoration: underline; }

  /* CORS notice */
  .cors-notice {
    background: rgba(240,160,75,0.08);
    border: 1px solid rgba(240,160,75,0.25);
    border-radius: var(--radius-sm);
    padding: 1rem 1.1rem;
    font-size: 0.8rem;
    color: #c8a96e;
    margin-bottom: 1.5rem;
    line-height: 1.55;
  }

  .cors-notice strong { color: var(--warn); }

  /* Dashboard grid */
  #dashboard { display: none; }

  .date-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 12px;
  }

  .date-controls { display: flex; align-items: center; gap: 8px; }
  .date-controls input[type=date] {
    padding: 0.45rem 0.75rem;
    background: var(--surface);
    border: 1px solid var(--border2);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 0.85rem;
  }
  .date-controls input[type=date]:focus { outline: none; border-color: var(--accent); }

  /* Metric cards */
  .metrics-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 12px;
    margin-bottom: 1.5rem;
  }

  .metric-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    position: relative;
    overflow: hidden;
  }

  .metric-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: var(--card-color, var(--accent));
  }

  .metric-label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--muted);
    margin-bottom: 0.5rem;
  }

  .metric-value {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--card-color, var(--text));
    line-height: 1;
    margin-bottom: 0.3rem;
  }

  .metric-delta {
    font-size: 0.78rem;
    color: var(--muted);
  }

  /* Charts */
  .charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 1.25rem;
    margin-bottom: 1.5rem;
  }

  .chart-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
  }

  .chart-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.25rem;
  }

  .chart-legend {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
  }

  .legend-item {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 0.78rem;
    color: var(--muted);
  }

  .legend-dot {
    width: 10px; height: 10px;
    border-radius: 2px;
  }

  .chart-wrap {
    position: relative;
    width: 100%;
    height: 260px;
  }

  /* Wellness 2×2 */
  .wellness-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
    margin-bottom: 1.5rem;
  }

  /* Loading / error states */
  .state-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 3rem;
    text-align: center;
    color: var(--muted);
  }

  .spinner {
    width: 36px; height: 36px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
  }

  @keyframes spin { to { transform: rotate(360deg); } }

  .error-box {
    background: rgba(224,92,92,0.08);
    border: 1px solid rgba(224,92,92,0.25);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
    color: #d97b7b;
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
    display: none;
  }

  /* Section labels */
  .section-label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--muted);
    padding-bottom: 0.65rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1.25rem;
  }

  /* Athlete info bar */
  .athlete-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1rem 1.25rem;
    margin-bottom: 1.5rem;
  }

  .athlete-avatar {
    width: 40px; height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    display: flex; align-items: center; justify-content: center;
    font-weight: 700; font-size: 1rem; color: #fff;
    flex-shrink: 0;
  }

  .athlete-name { font-weight: 600; font-size: 1rem; }
  .athlete-id { font-size: 0.8rem; color: var(--muted); }

  .status-badge {
    margin-left: auto;
    font-size: 0.75rem;
    padding: 4px 10px;
    border-radius: 20px;
    background: rgba(61,214,160,0.12);
    color: var(--accent2);
    border: 1px solid rgba(61,214,160,0.2);
    font-weight: 600;
  }

  /* Responsive */
  @media (max-width: 700px) {
    main { padding: 1rem; }
    header { padding: 1rem; }
    .charts-grid { grid-template-columns: 1fr; }
    .wellness-grid { grid-template-columns: 1fr; }
  }

  .btn-danger {
  background: #e05c5c !important;
  border-color: #e05c5c !important;
  }
  .btn-danger:hover {
  background: #d04c4c !important;
  border-color: #d04c4c !important;
  }