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

body {
  background: #050510;
  overflow: hidden;
  font-family: 'PingFang SC', 'Microsoft YaHei', -apple-system, sans-serif;
  color: #fff;
  user-select: none;
  -webkit-user-select: none;
}

#canvas-container { position: fixed; inset: 0; }

/* ─── Overlay ─── */
#ui-overlay { position: fixed; inset: 0; pointer-events: none; z-index: 10; }
#ui-overlay > * { pointer-events: auto; }

/* ─── Planet List ─── */
#planet-list {
  position: absolute; top: 50%; left: 20px; transform: translateY(-50%);
  display: flex; flex-direction: column; gap: 5px;
}

.planet-item {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 16px; border-radius: 10px; cursor: pointer;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.85rem; transition: all 0.25s;
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
}

.planet-item:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.18);
  transform: translateX(5px);
}

.planet-item.active {
  background: rgba(124, 58, 237, 0.3);
  border-color: rgba(124, 58, 237, 0.55);
  box-shadow: 0 0 24px rgba(124, 58, 237, 0.25);
}

.planet-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }

.reset-item {
  margin-top: 14px; border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 15px; border-radius: 0 0 10px 10px;
  font-size: 0.8rem; color: rgba(255,255,255,0.45); justify-content: center;
  gap: 4px;
}

/* ─── Info Panel ─── */
#info-panel {
  position: absolute; top: 24px; left: 50%; transform: translateX(-50%);
  text-align: center; background: rgba(8, 8, 20, 0.65);
  backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 16px; padding: 18px 36px; min-width: 300px;
}

#info-panel.hidden { display: none; }
#info-name { font-size: 1.6rem; font-weight: 800; letter-spacing: 0.02em; }
#info-desc { font-size: 0.82rem; color: rgba(255,255,255,0.45); margin-top: 4px; line-height: 1.5; }

/* ─── Controls Bar ─── */
#controls-bar {
  position: absolute; bottom: 30px; left: 50%; transform: translateX(-50%);
  display: flex; align-items: center; gap: 12px;
  background: rgba(8, 8, 20, 0.6);
  backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 24px; padding: 8px 20px;
}

#controls-bar button {
  width: 38px; height: 38px; border: none; border-radius: 50%;
  background: rgba(255, 255, 255, 0.07); color: #fff;
  font-size: 1.05rem; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: all 0.2s;
}

#controls-bar button:hover { background: rgba(255, 255, 255, 0.16); }
#controls-bar button:active { transform: scale(0.9); }
#controls-bar button.active { background: rgba(124, 58, 237, 0.35); }

#speed-display {
  font-size: 1rem; font-weight: 700; min-width: 38px; text-align: center;
  font-variant-numeric: tabular-nums;
}

/* ─── Hint ─── */
#hint {
  position: absolute; bottom: 100px; left: 50%; transform: translateX(-50%);
  font-size: 0.72rem; color: rgba(255,255,255,0.3);
  transition: opacity 1s; white-space: nowrap;
}

/* ─── Labels ─── */
.planet-label {
  font-size: 0.65rem; color: rgba(255, 255, 255, 0.65);
  text-shadow: 0 0 10px rgba(0, 0, 0, 0.9); pointer-events: none;
  white-space: nowrap;
}

/* ─── Responsive ─── */
@media (max-width: 768px) {
  #planet-list { left: 6px; gap: 3px; }
  .planet-item { padding: 6px 10px; font-size: 0.75rem; border-radius: 8px; gap: 6px; }
  .planet-dot { width: 8px; height: 8px; }
  #controls-bar { bottom: 18px; padding: 6px 14px; gap: 8px; border-radius: 18px; }
  #controls-bar button { width: 34px; height: 34px; font-size: 0.9rem; }
  #info-panel { top: 14px; padding: 12px 22px; min-width: auto; max-width: 88vw; border-radius: 14px; }
  #info-name { font-size: 1.3rem; }
  #hint { bottom: 80px; font-size: 0.65rem; max-width: 85vw; white-space: normal; text-align: center; line-height: 1.4; }
}

@media (max-width: 480px) {
  #planet-list { left: 4px; gap: 2px; }
  .planet-item { padding: 5px 8px; font-size: 0.68rem; border-radius: 6px; gap: 4px; }
  .planet-dot { width: 7px; height: 7px; }
  #controls-bar { bottom: 12px; padding: 4px 10px; gap: 5px; border-radius: 16px; }
  #controls-bar button { width: 30px; height: 30px; font-size: 0.8rem; }
  #speed-display { font-size: 0.85rem; min-width: 30px; }
  #info-panel { top: 10px; padding: 10px 16px; }
  #info-name { font-size: 1.1rem; }
  #info-desc { font-size: 0.7rem; }
}