:root {
  color-scheme: dark;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #0b1020;
  color: #edf2ff;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* {
  box-sizing: border-box;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  display: grid;
  place-items: center;
  padding: 32px 20px;
  background:
    radial-gradient(ellipse at 18% 0%, rgb(54 68 123 / 22%), transparent 40%),
    #0b1020;
}

.app {
  width: min(100%, 1100px);
}

.heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 22px;
}

.eyebrow {
  margin: 0 0 8px;
  color: #89a4ff;
  font-size: 0.72rem;
  font-weight: 750;
  letter-spacing: 0.14em;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 5vw, 3.25rem);
  letter-spacing: -0.045em;
}

.intro {
  margin: 10px 0 0;
  color: #aab5d0;
}

.status {
  flex: 0 0 auto;
  max-width: 280px;
  color: #aab5d0;
  font-size: 0.86rem;
  text-align: right;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 18px;
}

.simulation-panel,
.controls {
  border: 1px solid #27314d;
  border-radius: 18px;
  background: rgb(18 25 45 / 92%);
  box-shadow: 0 18px 60px rgb(0 0 0 / 22%);
}

.simulation-panel {
  min-width: 0;
  overflow: hidden;
  padding: 14px;
}

canvas {
  display: block;
  width: 100%;
  height: clamp(320px, 55vh, 560px);
  border: 1px solid #313e61;
  border-radius: 10px;
  background: #0b1225;
}

.legend {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 13px 3px 2px;
  color: #aab5d0;
  font-size: 0.84rem;
}

.particle-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #73d5ff;
  box-shadow: 0 0 11px rgb(115 213 255 / 75%);
}

.controls {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  padding: 22px;
}

.controls label {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin: 2px 0 12px;
  font-size: 0.9rem;
  font-weight: 650;
}

output {
  color: #9bb1ff;
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  width: 100%;
  margin: 0 0 25px;
  accent-color: #83a1ff;
}

button {
  min-height: 44px;
  border: 0;
  border-radius: 10px;
  background: #7895ff;
  color: #0a1020;
  cursor: pointer;
  font: inherit;
  font-weight: 750;
}

button:disabled {
  cursor: wait;
  opacity: 0.55;
}

button:not(:disabled):hover {
  background: #9bb0ff;
}

.metrics {
  display: grid;
  gap: 0;
  margin-top: 20px;
  border-top: 1px solid #27314d;
}

.metrics div {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 13px 0;
  border-bottom: 1px solid #27314d;
  color: #aab5d0;
  font-size: 0.84rem;
}

.metrics strong {
  color: #edf2ff;
  font-variant-numeric: tabular-nums;
}

.hint {
  margin: 17px 0 0;
  color: #818daa;
  font-size: 0.78rem;
  line-height: 1.5;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 15px;
  color: #818daa;
  font-size: 0.77rem;
}

@media (max-width: 760px) {
  body {
    place-items: start center;
    padding: 24px 14px;
  }

  .heading {
    align-items: flex-start;
    flex-direction: column;
    gap: 5px;
  }

  .status {
    margin: 0;
    text-align: left;
  }

  .layout {
    grid-template-columns: 1fr;
  }

  .controls {
    padding: 18px;
  }

  canvas {
    height: 48vh;
    min-height: 260px;
  }

  footer {
    flex-direction: column;
    gap: 5px;
  }
}