:root {
  --paper: #eaeede; /* slightly green off-white */
  --ink: #2b302a;
  --muted: #6f7a66;
  --faint: #9aa48d;
  --accent: #2f8f57; /* signal / primary — green */
  --accent2: #2f6f63; /* derivative / secondary */
  --amber: #b07d12;
  --mono: ui-monospace, 'SF Mono', SFMono-Regular, Menlo, Consolas,
    'Liberation Mono', monospace;
}

* {
  box-sizing: border-box;
}
[hidden] {
  display: none !important;
}
html,
body {
  margin: 0;
  padding: 0;
}
html {
  background: var(--paper);
}

body {
  font-family: var(--mono);
  color: var(--ink);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  background-color: var(--paper);
  /* gentle paper texture only — no graph-paper grid */
  background-image: url("data:image/svg+xml,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20width%3D%27140%27%20height%3D%27140%27%3E%3Cfilter%20id%3D%27n%27%3E%3CfeTurbulence%20type%3D%27fractalNoise%27%20baseFrequency%3D%270.85%27%20numOctaves%3D%272%27%20stitchTiles%3D%27stitch%27%2F%3E%3C%2Ffilter%3E%3Crect%20width%3D%27140%27%20height%3D%27140%27%20filter%3D%27url%28%23n%29%27%20opacity%3D%270.04%27%2F%3E%3C%2Fsvg%3E");
  background-size: 140px 140px;
}

.app {
  max-width: 780px;
  margin: 0 auto;
  padding: max(14px, env(safe-area-inset-top)) 14px max(20px, env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* corner-bracket frame, used on every module */
.frame {
  border: 9px solid transparent;
  border-image: url("data:image/svg+xml,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20width%3D%2744%27%20height%3D%2744%27%3E%3Cg%20fill%3D%27none%27%20stroke%3D%27%239aa48d%27%20stroke-width%3D%271%27%3E%3Cpath%20d%3D%27M1%2011V1H11%27%2F%3E%3Cpath%20d%3D%27M33%201H43V11%27%2F%3E%3Cpath%20d%3D%27M43%2033V43H33%27%2F%3E%3Cpath%20d%3D%27M11%2043H1V33%27%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E")
    11 stretch;
}

.dim {
  color: var(--faint);
}

/* header */
.hud {
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid rgba(60, 70, 50, 0.25);
  padding-bottom: 8px;
}
.hud-id {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}
.hud-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}
.heart {
  color: var(--accent);
  font-size: 1.2rem;
  line-height: 1;
}
.heart.on {
  animation: beat 1s infinite ease-in-out;
}
@keyframes beat {
  0%,
  100% {
    transform: scale(1);
  }
  18% {
    transform: scale(1.35);
  }
  32% {
    transform: scale(1);
  }
}
.status {
  flex: 1 1 auto;
  min-width: 0;
  text-align: left;
  line-height: 1.3;
  font-size: 0.62rem;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.cam-wrap {
  position: relative;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  overflow: hidden;
  border: 1px solid var(--ink);
  background: #000;
  flex: none;
}
.cam-wrap video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.rec {
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
}
.rec-dot {
  display: block;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  animation: blink 1s steps(2, start) infinite;
}
@keyframes blink {
  50% {
    opacity: 0.2;
  }
}

/* readout strip */
.readout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
@media (min-width: 560px) {
  .readout {
    grid-template-columns: minmax(180px, 1fr) 2fr;
    align-items: stretch;
  }
}
.bpm-block {
  padding: 8px 12px 10px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.bpm-line {
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.bpm {
  font-size: 3.4rem;
  font-weight: 700;
  line-height: 0.95;
  font-variant-numeric: tabular-nums;
  letter-spacing: -1px;
}
.unit {
  color: var(--muted);
  font-size: 0.7rem;
  letter-spacing: 2px;
  text-transform: uppercase;
}
.bpm-avg {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.6rem;
  letter-spacing: 1.5px;
  text-transform: uppercase;
}
.bpm-avg span {
  color: var(--ink);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
/* acquisition / viability progress until the rate locks */
.acq {
  margin-top: 8px;
  height: 4px;
  background: rgba(90, 110, 80, 0.18);
  border-radius: 2px;
  overflow: hidden;
}
.acq-fill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.2s linear;
}
.cells {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.cell {
  padding: 7px 8px 8px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.cell-label {
  font-size: 0.5rem;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--muted);
}
.cell-val {
  font-size: 1.15rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1;
}
.cell-val.sm {
  font-size: 0.72rem;
  font-weight: 700;
}
.cell-unit {
  font-size: 0.5rem;
  color: var(--faint);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* chart grid */
.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
@media (min-width: 560px) {
  .grid {
    grid-template-columns: 1fr 1fr;
  }
  .span2 {
    grid-column: 1 / -1;
  }
}
.panel {
  padding: 6px 8px 8px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 0.56rem;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--muted);
}
.panel-head span:last-child {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.chart {
  width: 100%;
  height: 92px;
  display: block;
}
.chart.tall {
  height: 150px;
}
.span2 .chart {
  height: 108px;
}

/* acquire / stop — compact, lives in the header top-right */
.btn {
  flex: none;
  padding: 7px 9px;
  font-family: var(--mono);
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--ink);
  border-radius: 2px;
  cursor: pointer;
  white-space: nowrap;
  -webkit-tap-highlight-color: transparent;
}
.btn:active {
  transform: translateY(1px);
}
.btn.primary {
  background: var(--accent);
  color: #f3efe6;
  border-color: var(--accent);
  animation: press-hint 2s ease-in-out infinite;
}
/* gentle "press me" cue — a slight depress plus a soft expanding ring */
@keyframes press-hint {
  0%,
  100% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(47, 143, 87, 0.35);
  }
  50% {
    transform: scale(0.97);
    box-shadow: 0 0 0 5px rgba(47, 143, 87, 0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .btn.primary {
    animation: none;
  }
}
.btn:disabled {
  opacity: 0.5;
}

.cam-select-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 0.58rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--muted);
}
.cam-select-row select {
  flex: 1;
  max-width: 280px;
  padding: 8px 10px;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--paper);
  color: var(--ink);
  font: inherit;
  font-size: 0.62rem;
}

.perm-note {
  color: var(--amber);
  font-size: 0.6rem;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  text-align: center;
  line-height: 1.5;
  margin: 0;
}

/* help */
.help {
  font-size: 0.82rem;
  color: var(--muted);
  border-top: 1px solid rgba(60, 70, 50, 0.25);
  padding-top: 10px;
}
.help summary {
  cursor: pointer;
  color: var(--ink);
  font-size: 0.62rem;
  letter-spacing: 1.5px;
  text-transform: uppercase;
}
.help p,
.help ul,
.help li {
  line-height: 1.55;
}
.help ul {
  padding-left: 18px;
}
.help strong {
  color: var(--ink);
}
.help em {
  font-style: normal;
  color: var(--accent2);
}
.disclaimer {
  font-size: 0.74rem;
  opacity: 0.85;
}