:root {
  --bg: #080914;
  --panel: #101527;
  --panel-2: #151d33;
  --text: #f8fbff;
  --muted: #9fb0c6;
  --line: rgba(160, 185, 220, 0.18);
  --cyan: #00f5ff;
  --purple: #bf5fff;
  --green: #00ff88;
  --red: #ff3860;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: "Plus Jakarta Sans", Arial, sans-serif;
}

button,
input {
  font: inherit;
}

.toolbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 20;
  padding: 0.7rem;
  background: rgba(16, 21, 39, 0.96);
  border-bottom: 1px solid rgba(0, 245, 255, 0.25);
  backdrop-filter: blur(14px);
}

.toolbar-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem;
}

.toolbar-title {
  min-width: 190px;
}

.toolbar-title p {
  margin: 0 0 0.15rem;
  color: var(--muted);
  font-family: "JetBrains Mono", monospace;
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.toolbar h1 {
  margin: 0;
  color: var(--cyan);
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  white-space: nowrap;
}

.control-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
}

.control-label {
  color: #8fffe0;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.btn {
  border: 1px solid rgba(0, 245, 255, 0.5);
  border-radius: 999px;
  padding: 0.42rem 0.74rem;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  cursor: pointer;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  transition:
    background 160ms ease,
    color 160ms ease,
    border-color 160ms ease,
    box-shadow 160ms ease;
}

.btn:hover,
.btn.active {
  background: var(--cyan);
  color: var(--bg);
  border-color: var(--cyan);
  box-shadow: 0 0 18px rgba(0, 245, 255, 0.45);
}

.danger-btn {
  border-color: rgba(255, 56, 96, 0.7);
}

.danger-btn:hover {
  background: var(--red);
  color: #fff;
  border-color: var(--red);
}

.toggle-btn.active {
  background: var(--green);
  color: var(--bg);
  border-color: var(--green);
}

.slider-group {
  width: 112px;
}

.slider-group label {
  display: block;
  margin-bottom: 0.15rem;
  color: #b7bdd5;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.68rem;
  text-transform: uppercase;
}

.form-range {
  width: 100%;
  accent-color: var(--cyan);
}

.color-swatch {
  width: 24px;
  height: 24px;
  padding: 0;
  border: 2px solid transparent;
  border-radius: 999px;
  cursor: pointer;
}

.color-swatch.active {
  border-color: #fff;
  box-shadow: 0 0 14px rgba(255, 255, 255, 0.65);
}

.playground {
  position: relative;
  width: 100vw;
  height: 100vh;
  padding-top: 98px;
}

#physics-canvas {
  display: block;
  width: 100%;
  height: 100%;
  cursor: crosshair;
  background:
    radial-gradient(circle at top, rgba(191, 95, 255, 0.18), transparent 35%),
    radial-gradient(
      circle at bottom left,
      rgba(0, 245, 255, 0.12),
      transparent 35%
    ),
    #0a0a18;
}

.info-panel {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  width: min(340px, calc(100vw - 2rem));
  background: rgba(10, 10, 24, 0.9);
  border: 1px solid rgba(191, 95, 255, 0.35);
  border-radius: 10px;
  color: var(--text);
  backdrop-filter: blur(12px);
  box-shadow: 0 0 24px rgba(191, 95, 255, 0.18);
}

.panel-body {
  padding: 1rem;
}

.info-panel h2 {
  margin: 0 0 0.55rem;
  color: var(--cyan);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.info-panel h2:not(:first-child) {
  margin-top: 1rem;
}

#sim-stats,
#body-stats {
  color: #cfd3ff;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.76rem;
}

.stat-line {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.25rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.stat-label {
  color: #8fffe0;
}

.stat-value {
  color: var(--text);
  text-align: right;
}

@media (max-width: 992px) {
  body {
    overflow: auto;
  }

  .playground {
    height: 100dvh;
    padding-top: 220px;
  }

  .slider-group {
    width: 96px;
  }

  .info-panel {
    left: 0.75rem;
    right: 0.75rem;
    bottom: 0.75rem;
    width: auto;
  }
}

@media (max-width: 576px) {
  .toolbar-row {
    gap: 0.45rem;
  }

  .toolbar-title {
    width: 100%;
  }

  .toolbar h1 {
    font-size: 0.9rem;
  }

  .btn {
    font-size: 0.65rem;
    padding: 0.34rem 0.55rem;
  }

  .playground {
    padding-top: 280px;
  }

  .info-panel {
    max-height: 190px;
    overflow-y: auto;
  }
}