:root {
  --bg: radial-gradient(circle at 20% 20%, #122433, #0b1620 45%, #090e18 70%);
  --panel: rgba(12, 18, 30, 0.88);
  --accent: #4cd2ff;
  --accent-2: #9dff9b;
  --text: #e8f2ff;
  --muted: #98a7bc;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  overflow: hidden;
}

#scene-container {
  width: 100vw;
  height: 100vh;
}

canvas {
  display: block;
}

#hud {
  position: absolute;
  top: 16px;
  left: 16px;
  width: 320px;
  max-height: calc(100vh - 32px);
  overflow-y: auto;
  padding: 14px 16px;
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.06);
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.35);
  border-radius: 12px;
  backdrop-filter: blur(10px);
  z-index: 10;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

body.hud-collapsed #hud {
  transform: translateX(calc(-100% - 24px));
  opacity: 0;
  pointer-events: none;
}

#hud::-webkit-scrollbar {
  width: 6px;
}

#hud::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 3px;
}

.title-row {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 8px;
}

.title {
  font-weight: 700;
  font-size: 20px;
  letter-spacing: 0.4px;
}

.subtitle {
  color: var(--muted);
  font-size: 12px;
}

.pill {
  display: inline-block;
  margin-left: 8px;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 700;
  background: rgba(76, 210, 255, 0.16);
  color: #b8ecff;
  border-radius: 999px;
  border: 1px solid rgba(76, 210, 255, 0.45);
}

.section-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent);
  margin-top: 14px;
  margin-bottom: 6px;
  padding-bottom: 4px;
  border-bottom: 1px solid rgba(76, 210, 255, 0.2);
}

.control {
  margin: 10px 0;
}

label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 5px;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  height: 6px;
}

.buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

button {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: border 0.15s ease, background 0.15s ease, transform 0.1s ease;
}

button:hover {
  border-color: rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.08);
}

button:active {
  transform: translateY(1px);
}

button.tool.active {
  background: rgba(76, 210, 255, 0.14);
  border-color: rgba(76, 210, 255, 0.6);
  color: #dff7ff;
  box-shadow: 0 0 0 1px rgba(76, 210, 255, 0.22);
}

.buttons.secondary button {
  flex: 1 1 0;
  font-size: 12px;
  padding: 8px 6px;
}

/* Toggles */
.toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
}

.toggle-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text);
  cursor: pointer;
  margin-bottom: 0;
}

.toggle-label input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

/* Color pickers */
.color-row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.color-row label {
  margin-bottom: 0;
  font-size: 12px;
  flex-shrink: 0;
}

.color-row input[type="color"] {
  width: 32px;
  height: 26px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 5px;
  background: rgba(255, 255, 255, 0.05);
  cursor: pointer;
  padding: 2px;
}

.color-row input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 2px;
}

.color-row input[type="color"]::-webkit-color-swatch {
  border-radius: 3px;
  border: none;
}

/* Hints */
.hint {
  color: var(--muted);
  font-size: 11px;
  line-height: 1.5;
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.hint p {
  margin: 4px 0;
}

#hud-toggle {
  position: absolute;
  top: 16px;
  left: 352px;
  z-index: 12;
  background: rgba(12, 18, 30, 0.92);
  color: var(--text);
  border: 1px solid rgba(76, 210, 255, 0.4);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.35);
  transition: transform 0.2s ease, border 0.2s ease, background 0.2s ease, opacity 0.25s ease;
}

#hud-toggle:hover {
  transform: translateY(-1px);
  background: rgba(76, 210, 255, 0.16);
  border-color: rgba(76, 210, 255, 0.7);
}

body.hud-collapsed #hud-toggle {
  left: 16px;
  opacity: 0.9;
}

/* Responsive */
@media (max-width: 640px) {
  #hud {
    width: calc(100vw - 24px);
    left: 12px;
    max-height: 50vh;
  }
  .buttons {
    flex-direction: column;
  }
  .toggles {
    flex-direction: column;
    gap: 8px;
  }
}