* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #87c5e8;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
}

#app,
#app canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.hud {
  position: fixed;
  top: 20px;
  left: 20px;
  padding: 14px 18px;
  border-radius: 12px;
  background: rgba(20, 32, 24, 0.55);
  backdrop-filter: blur(6px);
  color: #eef6ea;
  user-select: none;
}

.hud h1 {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.hud p {
  margin-top: 4px;
  font-size: 12px;
  opacity: 0.75;
}

.hud p.hint {
  opacity: 0.55;
  font-style: italic;
}

.controls {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
  font-size: 12px;
}

.row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  font-size: 12px;
}

.row .lbl {
  opacity: 0.7;
  margin-right: 2px;
}

.row button {
  padding: 4px 10px;
  border: 1px solid rgba(238, 246, 234, 0.4);
  border-radius: 6px;
  background: transparent;
  color: #eef6ea;
  font-size: 12px;
  cursor: pointer;
}

.row button:hover {
  background: rgba(238, 246, 234, 0.15);
}

.row button.active {
  background: rgba(159, 208, 106, 0.85);
  border-color: transparent;
  color: #1c2a14;
  font-weight: 600;
}

.controls input[type="range"] {
  width: 110px;
  accent-color: #9fd06a;
  cursor: pointer;
}