/* =====================================================================
 * styles.css — mobile-first dark UI for the HR Tracker.
 * No framework, no build step.
 * ===================================================================== */

:root {
  --bg: #0b0f1a;
  --bg-2: #0f1626;
  --card: #131c2e;
  --card-2: #16213a;
  --line: rgba(255, 255, 255, 0.07);
  --line-2: rgba(255, 255, 255, 0.12);
  --text: #e7eefc;
  --muted: #8b9ab8;
  --dim: #5d6b86;
  --accent: #22d3ee;
  --accent-2: #34d399;
  --pink: #fb7185;
  --warn: #fbbf24;
  --good: #34d399;
  --bad: #f87171;
  --radius: 16px;
  --pad: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0;
  padding: 0;
  background:
    radial-gradient(1200px 600px at 50% -10%, #16223d 0%, transparent 60%),
    var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

body {
  max-width: 560px;
  margin: 0 auto;
  padding: var(--pad);
  padding-top: calc(env(safe-area-inset-top, 0px) + 8px);
  min-height: 100vh;
}

.hidden { display: none !important; }

/* ============================ HEADER ============================ */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 4px 14px;
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(8px);
  background: linear-gradient(180deg, rgba(11,15,26,0.96) 60%, rgba(11,15,26,0));
}
.brand { display: flex; align-items: center; gap: 10px; }
.logo {
  font-size: 24px;
  color: var(--pink);
  filter: drop-shadow(0 0 8px rgba(251,113,133,0.6));
  animation: idle 2.4s ease-in-out infinite;
}
@keyframes idle { 0%,100% { transform: scale(1); } 50% { transform: scale(1.12); } }
.brand h1 { margin: 0; font-size: 17px; letter-spacing: 0.2px; }
.brand .sub { margin: 0; font-size: 11px; color: var(--muted); }

.status { display: flex; align-items: center; gap: 7px; font-size: 12px; color: var(--muted); }
.dot { width: 9px; height: 9px; border-radius: 50%; background: var(--dim); box-shadow: 0 0 0 0 rgba(0,0,0,0); }
.dot.off { background: var(--dim); }
.dot.connecting { background: var(--warn); animation: pulse 1s ease-in-out infinite; }
.dot.on { background: var(--good); box-shadow: 0 0 10px var(--good); }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.35; } }

/* ============================ CARDS ============================= */
.card {
  background: linear-gradient(180deg, var(--card) 0%, var(--bg-2) 100%);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  margin-bottom: 12px;
}
.card-head {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 10px; gap: 8px;
}
.card-head h2 { margin: 0; font-size: 14px; text-transform: uppercase; letter-spacing: 0.6px; color: var(--text); }
.card-head h2 small { text-transform: none; letter-spacing: 0; color: var(--muted); font-weight: 400; font-size: 12px; }

.hint { font-size: 12px; color: var(--muted); margin: 8px 2px 0; }

/* ============================ BANNER ============================ */
.banner {
  background: rgba(248,113,113,0.12);
  border: 1px solid rgba(248,113,113,0.4);
  color: #fecaca;
  padding: 10px 12px;
  border-radius: 12px;
  font-size: 13px;
  margin-bottom: 12px;
}
.banner code { background: rgba(0,0,0,0.3); padding: 1px 5px; border-radius: 4px; }

/* ============================ BUTTONS =========================== */
.btn {
  appearance: none;
  border: 1px solid var(--line-2);
  background: var(--card-2);
  color: var(--text);
  padding: 11px 16px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.06s ease, background 0.15s ease, opacity 0.15s;
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
}
.btn:active { transform: scale(0.97); }
.btn.primary {
  background: linear-gradient(135deg, var(--accent) 0%, #0ea5b7 100%);
  border: none; color: #04161a; width: 100%;
  box-shadow: 0 6px 20px rgba(34,211,238,0.25);
}
.btn.ghost { background: transparent; }
.btn.tiny { padding: 6px 12px; font-size: 12px; border-radius: 9px; }
.btn:disabled { opacity: 0.5; }
.bt-icon { font-size: 18px; line-height: 1; }

/* segmented control */
.seg { display: inline-flex; background: rgba(0,0,0,0.25); border: 1px solid var(--line); border-radius: 9px; overflow: hidden; }
.seg button {
  appearance: none; border: none; background: transparent; color: var(--muted);
  padding: 6px 10px; font-size: 12px; cursor: pointer; font-weight: 600;
}
.seg button.on { background: var(--accent); color: #04161a; }

/* ===================== CONNECT / DEVICE INFO ==================== */
.connect-card .btn + .btn { margin-top: 8px; }
.device-info { margin-top: 12px; display: grid; gap: 6px; }
.di-row {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 13px; padding: 6px 8px; background: rgba(0,0,0,0.2);
  border-radius: 8px;
}
.di-row span { color: var(--muted); }
.di-row b { font-weight: 600; text-align: right; word-break: break-word; }

/* ===================== LIVE BPM CARD =========================== */
.live-card { text-align: center; padding: 18px 14px; }
.bpm-wrap { display: flex; align-items: center; justify-content: center; gap: 14px; }
.heart {
  font-size: 52px; color: var(--pink);
  filter: drop-shadow(0 0 18px rgba(251,113,133,0.55));
  transition: transform 0.08s ease;
}
.heart.beat { transform: scale(1.35); }
.bpm-num { display: flex; flex-direction: column; align-items: flex-start; }
.bpm-num span { font-size: 64px; font-weight: 800; line-height: 0.9;
  font-variant-numeric: tabular-nums; letter-spacing: -2px; }
.bpm-num small { font-size: 14px; color: var(--muted); text-transform: uppercase; letter-spacing: 2px; }

.live-meta { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-top: 16px; }
.chip {
  background: rgba(0,0,0,0.25); border: 1px solid var(--line); border-radius: 10px; padding: 8px 6px;
  display: flex; flex-direction: column; gap: 2px;
}
.chip span { font-size: 10px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.5px; }
.chip b { font-size: 14px; font-variant-numeric: tabular-nums; }

/* ===================== CHARTS ================================== */
.chart-canvas {
  width: 100%; height: 150px; display: block;
  border-radius: 10px; background: rgba(0,0,0,0.25);
  border: 1px solid var(--line);
}
#beatCanvas { height: 130px; }
#bpmCanvas { height: 140px; }

/* ===================== HRV METRIC GRID ========================= */
.metric-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.metric {
  background: rgba(0,0,0,0.25); border: 1px solid var(--line); border-radius: 10px;
  padding: 10px 6px; text-align: center; display: flex; flex-direction: column; gap: 2px;
}
.metric span { font-size: 10px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.5px; }
.metric b { font-size: 18px; font-weight: 700; font-variant-numeric: tabular-nums; }
.metric i { font-size: 10px; color: var(--dim); font-style: normal; }
.metric.hl { background: linear-gradient(160deg, rgba(34,211,238,0.18), rgba(52,211,153,0.10)); border-color: rgba(34,211,238,0.4); }
.metric.hl b { color: var(--accent); }

/* ===================== GATT TREE ============================== */
.gatt-tree { display: grid; gap: 8px; }
.svc {
  background: rgba(0,0,0,0.2); border: 1px solid var(--line); border-radius: 10px; overflow: hidden;
}
.svc-head {
  padding: 8px 10px; background: rgba(255,255,255,0.03);
  font-size: 12px; font-weight: 700; letter-spacing: 0.3px;
  display: flex; justify-content: space-between; align-items: center; gap: 8px;
}
.svc-head .uuid { color: var(--muted); font-weight: 400; font-size: 10px; font-family: ui-monospace, monospace; }
.char-list { padding: 4px 6px 6px; display: grid; gap: 4px; }
.char {
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
  padding: 7px 8px; border-radius: 8px; background: rgba(0,0,0,0.18);
  font-size: 12px;
}
.char .cname { font-weight: 600; }
.char .cuuid { color: var(--dim); font-size: 10px; font-family: ui-monospace, monospace; }
.char .cval { color: var(--accent-2); font-size: 11px; font-family: ui-monospace, monospace; max-width: 45%; text-align: right; word-break: break-all; }
.props { display: inline-flex; gap: 3px; flex-wrap: wrap; }
.prop {
  font-size: 9px; padding: 2px 5px; border-radius: 5px; text-transform: uppercase;
  background: rgba(255,255,255,0.06); color: var(--muted); letter-spacing: 0.4px;
}
.prop.read { background: rgba(52,211,153,0.15); color: var(--good); }
.prop.write { background: rgba(251,191,36,0.15); color: var(--warn); }
.prop.notify, .prop.indicate { background: rgba(34,211,238,0.15); color: var(--accent); }
.char.readable { cursor: pointer; }
.char.readable:active { background: rgba(255,255,255,0.08); }
.spinner { font-size: 11px; color: var(--muted); }

/* ===================== RAW LOG ================================ */
.rawlog {
  background: #06090f; border: 1px solid var(--line); border-radius: 10px;
  padding: 10px; margin: 0; font-family: ui-monospace, monospace; font-size: 11px;
  color: var(--muted); max-height: 260px; overflow: auto; white-space: pre-wrap; word-break: break-word;
}
.log-actions { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 8px; }
.log-actions .btn { flex: 1 1 auto; min-width: 78px; }
.btn.on { background: rgba(52,211,153,0.18); border-color: rgba(52,211,153,0.4); color: var(--good); }
.btn.accent { background: rgba(34,211,238,0.15); border-color: rgba(34,211,238,0.4); color: var(--accent); }

/* ===================== FOOTER ================================= */
.foot { text-align: center; color: var(--dim); font-size: 11px; padding: 10px 0 24px; }

/* ===================== RESPONSIVE ============================= */
@media (min-width: 600px) {
  body { font-size: 16px; }
  .chart-canvas { height: 180px; }
  #beatCanvas { height: 160px; }
}

@media (prefers-color-scheme: light) {
  /* keep dark — this is a cockpit-style app */
}