:root {
  color-scheme: dark;
  --bg: #090d0b;
  --surface: #111913;
  --surface-press: #1a2b1f;
  --separator: #28352c;
  --text: #eff3ed;
  --muted: #97a99b;
  --quiet: #68796e;
  --accent: #b5dabc;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { width: 100%; height: 100%; margin: 0; background: var(--bg); overscroll-behavior: none; }
body {
  min-width: 280px; overflow: hidden; color: var(--text);
  font: 14px/1.35 "Segoe UI", Roboto, system-ui, sans-serif;
  -webkit-tap-highlight-color: transparent;
  -webkit-text-size-adjust: 100%;
}
button, input { color: inherit; font: inherit; }
button { cursor: pointer; }
button:focus-visible, a:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 3px;
}
.app {
  display: flex; flex-direction: column;
  width: 100%; height: 100vh; height: 100svh;
  min-height: 0; overflow: hidden;
}
.topbar {
  display: grid; grid-template-columns: 42px minmax(0,1fr) auto; align-items: center;
  flex: none; width: min(100%,600px);
  height: calc(56px + env(safe-area-inset-top));
  margin: 0 auto; padding: env(safe-area-inset-top) 15px 0;
}
.topbar h1 {
  margin: 0; font-size: 13px; font-weight: 600; text-align: center;
  font-variant: small-caps; letter-spacing: .19em;
}
.topbar-actions { display: flex; align-items: center; gap: 2px; }
.home, .reset, .settings-toggle, .settings-close {
  display: grid; place-items: center;
  width: 42px; height: 42px; padding: 0;
  border: 0; background: none; border-radius: 8px; color: var(--muted);
}
.home svg { width: 21px; height: 21px; }
.reset svg, .settings-toggle svg, .settings-close svg { width: 19px; height: 19px; }
.home:active, .reset:active, .settings-toggle:active, .settings-close:active { background: var(--surface-press); }
.settings-toggle[aria-expanded="true"] { color: var(--accent); }
main {
  display: flex; flex-direction: column; flex: 1; min-height: 0;
  width: min(100%,600px); margin: 0 auto;
  gap: clamp(11px,2svh,19px);
  padding: 8px 18px calc(12px + env(safe-area-inset-bottom));
}
.readout {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  flex: none; min-height: 110px; padding: 4px 0 0;
  font-variant-numeric: tabular-nums;
}
.bpm-line { display: flex; align-items: baseline; justify-content: center; gap: 10px; }
.bpm-value {
  display: inline-flex; align-items: baseline;
  font-size: clamp(76px,23vw,116px); line-height: .93; font-weight: 300;
  letter-spacing: -.063em; color: var(--text);
  font-variant-numeric: tabular-nums;
}
.bpm-fraction {
  margin-left: .03em; font-size: .38em; font-weight: 400;
  color: var(--quiet); letter-spacing: -.035em;
}
.unit { color: var(--accent); font-size: 13px; letter-spacing: .01em; }
.average-note { margin: 7px 0 0; color: var(--quiet); font-size: 11px; }
.precision {
  display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 5px;
  align-items: start; width: 100%; margin-top: 12px;
  font-variant-numeric: tabular-nums;
}
.precision-item { display: flex; flex-direction: column; align-items: center; min-width: 0; gap: 3px; }
.precision-label { color: var(--quiet); font-size: 11px; letter-spacing: .01em; white-space: nowrap; }
.precision-value { color: var(--text); font-size: clamp(10px,2.8vw,13px); line-height: 1.25; white-space: nowrap; }
.chart-panel {
  display: flex; flex-direction: column; flex: none;
  height: clamp(125px,19svh,170px);
  border-top: 1px solid var(--separator);
}
.chart-heading {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 3px 8px;
  align-items: baseline; flex: none; padding: 9px 0 0;
  color: var(--muted); font-size: 11px;
}
.chart-range { margin-left: auto; white-space: pre; color: var(--quiet); font-variant-numeric: tabular-nums; }
.chart { display: block; flex: 1; min-height: 0; width: 100%; overflow: visible; }
.chart-rule { stroke: #27342a; stroke-width: 1; vector-effect: non-scaling-stroke; }
.chart-tick { fill: var(--quiet); font: 12px "Segoe UI", Roboto, system-ui, sans-serif; }
.chart-ci95 { fill: #668d70; fill-opacity: .27; }
.chart-ci68 { fill: #a1d3a9; fill-opacity: .36; }
.chart-segment {
  stroke: var(--accent); stroke-width: 2.2; stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}
.chart-end { fill: var(--accent); stroke: var(--bg); stroke-width: 2; vector-effect: non-scaling-stroke; }
.interaction { display: flex; flex: 1; min-height: 140px; }
.beat-button {
  position: relative; isolation: isolate; overflow: hidden;
  display: grid; place-items: center; width: 100%; min-height: 140px;
  padding: 0; border: 1px solid #527c5b; border-radius: 15px;
  background: #1b3523; color: #d7f4dd;
  font-size: clamp(34px, 9vw, 46px); font-weight: 500; letter-spacing: .09em;
  touch-action: none; user-select: none; -webkit-user-select: none;
  -webkit-touch-callout: none;
  transition: background-color 100ms ease-out, border-color 100ms ease-out;
}
.beat-button span { position: relative; z-index: 1; pointer-events: none; transition: transform 100ms ease-out; }
.beat-button:active, .beat-button.is-pressed { background: #285036; border-color: #9bd3a7; }
.beat-button.is-pressed span { transform: scale(.96); }
.beat-button::before, .beat-button::after { position: absolute; content: ""; pointer-events: none; }
.beat-button::before { inset: 0; background: #9bd3a7; opacity: 0; }
.beat-button::after {
  top: var(--tap-y, 50%); left: var(--tap-x, 50%);
  width: min(64vmin, 300px); aspect-ratio: 1; border: 2px solid #b5e4bd;
  border-radius: 50%; opacity: 0;
  transform: translate(-50%, -50%) scale(.18);
}
.beat-button.is-hit::before { animation: beat-flash 280ms ease-out both; }
.beat-button.is-hit::after { animation: beat-wave 340ms ease-out both; }
@keyframes beat-flash {
  0% { opacity: .24; }
  100% { opacity: 0; }
}
@keyframes beat-wave {
  0% { opacity: .78; transform: translate(-50%, -50%) scale(.18); }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(1.5); }
}
.settings {
  position: fixed; z-index: 10; bottom: 0; left: 50%;
  display: flex; flex-direction: column; gap: 10px;
  width: min(100%, 600px); max-height: min(76svh, 560px);
  padding: 12px 18px calc(18px + env(safe-area-inset-bottom));
  overflow-x: hidden; overflow-y: auto; overscroll-behavior: contain;
  border-top: 1px solid #456f50; border-radius: 16px 16px 0 0;
  background: #141f17; visibility: hidden; pointer-events: none;
  transform: translate(-50%, 105%);
  transition: transform 260ms cubic-bezier(.2,.85,.2,1), visibility 260ms;
}
.settings.is-open { visibility: visible; pointer-events: auto; transform: translate(-50%, 0); }
.settings-header {
  display: flex; flex: none; justify-content: space-between; align-items: center;
  min-height: 38px;
}
.settings-header h2 {
  margin: 0; color: var(--text); font-size: 13px; font-weight: 600;
  font-variant: small-caps; letter-spacing: .14em;
}
.settings-close { margin: -4px -8px -4px 0; }
.settings-content { display: flex; flex-direction: column; gap: 14px; }
.window-setting, .mode-setting {
  display: grid; grid-template-columns: 82px minmax(0,1fr);
  align-items: center; column-gap: 14px;
}
.setting-label, .haptic-head label, .strength-head label {
  color: var(--muted); font-size: 11px; font-variant: small-caps; letter-spacing: .09em;
}
.segments, .mode-switch {
  display: grid; gap: 0; min-width: 0; background: transparent;
  border-bottom: 1px solid var(--separator); padding: 0;
}
.segments { grid-template-columns: repeat(4,minmax(0,1fr)); }
.mode-switch { grid-template-columns: repeat(2,minmax(0,1fr)); }
.segments button, .mode-switch button {
  min-width: 0; min-height: 33px; padding: 0 5px; background: none;
  border: 0; border-bottom: 2px solid transparent; border-radius: 0;
  color: var(--quiet); font-size: 12px;
}
.segments button[aria-pressed="true"], .mode-switch button[aria-pressed="true"] {
  border-bottom-color: var(--accent); color: var(--accent);
}
.segments button:active, .mode-switch button:active { color: var(--text); }
.haptic-setting { display: flex; flex-direction: column; gap: 6px; }
.haptic-head, .strength-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.haptic-head { min-height: 27px; }
.toggle {
  appearance: none; width: 39px; height: 23px; flex: none; margin: 0;
  border: 1px solid #425446; border-radius: 99px; background: #19231c;
  cursor: pointer;
}
.toggle::before {
  display: block; width: 15px; height: 15px; margin: 3px;
  background: #809485; border-radius: 50%; content: "";
  transition: transform 120ms ease;
}
.toggle:checked { background: #547e5b; border-color: #547e5b; }
.toggle:checked::before { transform: translateX(16px); background: #eff3ed; }
.toggle:disabled { opacity: .4; }
.haptic-strength-setting, .motion-sensitivity-setting { padding-bottom: 1px; }
.strength-head output { color: var(--quiet); font-size: 11px; font-variant-numeric: tabular-nums; }
.strength-slider {
  appearance: none; display: block; width: 100%; height: 21px;
  margin: 1px 0 0; background: none; cursor: pointer;
}
.strength-slider::-webkit-slider-runnable-track { height: 5px; background: #334637; border-radius: 99px; }
.strength-slider::-moz-range-track { height: 5px; background: #334637; border-radius: 99px; }
.strength-slider::-webkit-slider-thumb {
  appearance: none; width: 13px; height: 13px; margin-top: -4px;
  border: 0; border-radius: 50%; background: var(--accent);
}
.strength-slider::-moz-range-thumb { width: 13px; height: 13px; border: 0; border-radius: 50%; background: var(--accent); }
.mode-status, .haptic-status { grid-column: 2; margin: 5px 0 0; color: var(--quiet); font-size: 11px; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
@media (max-width:360px) {
  main { padding-inline: 12px; gap: 9px; }
  .window-setting,.mode-setting { grid-template-columns: 70px minmax(0,1fr); column-gap: 7px; }
}
@media (max-height:690px) and (orientation:portrait) {
  main { gap: 6px; padding-top: 2px; padding-bottom: calc(6px + env(safe-area-inset-bottom)); }
  .readout { min-height: 85px; padding: 0; }
  .bpm-value { font-size: clamp(60px,20vw,82px); }
  .average-note { margin-top: 4px; }
  .precision { margin-top: 5px; }
  .precision-item { gap: 1px; }
  .chart-panel { height: clamp(86px,14svh,110px); }
  .settings-content { gap: 10px; }
  .segments button,.mode-switch button { min-height: 30px; }
}
@media (orientation:landscape) and (max-height:620px) {
  main {
    display: grid; grid-template-columns: minmax(0,1fr) minmax(160px,.9fr);
    grid-template-rows: auto minmax(80px,1fr) auto;
    gap: 5px 16px; padding-top: 0;
    padding-bottom: calc(env(safe-area-inset-bottom) + 6px);
  }
  .readout { grid-column: 1; grid-row: 1; min-height: 0; padding: 0; }
  .bpm-value { font-size: clamp(43px,13vh,67px); }
  .average-note { margin-top: 2px; }
  .precision { margin-top: 5px; }
  .precision-value { font-size: 10px; }
  .chart-panel { grid-column: 1; grid-row: 2; height: auto; min-height: 80px; }
  .chart-heading { font-size: 10px; column-gap: 6px; }
  .chart-heading > span:first-child { white-space: nowrap; }
  .precision-label { font-size: 10px; }
  .precision-value { font-size: 10px; }
  .interaction { grid-column: 2; grid-row: 1 / 3; min-height: 0; }
  .beat-button { min-height: 0; }
  .settings { max-height: 86svh; }
  .settings-content {
    display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr);
    align-items: start; gap: 10px 16px;
  }
  .window-setting { grid-column: 1; grid-row: 1; }
  .mode-setting { grid-column: 2; grid-row: 1; }
  .window-setting, .mode-setting { grid-template-columns: 60px minmax(0,1fr); column-gap: 7px; }
  .haptic-setting { grid-column: 1; grid-row: 2; }
  .motion-sensitivity-setting { grid-column: 2; grid-row: 2; }
  .mode-status { grid-column: 1 / -1; margin-top: 2px; }
  .haptic-head { min-height: 25px; }
  .haptic-strength-setting { padding-bottom: 0; }
}
@media (prefers-reduced-motion: reduce) {
  *,*::before,*::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}