/* Reset & base */
* { box-sizing: border-box; }
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  color: #eef2f6;
  font: 500 14px/1.4 ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial;
  background: radial-gradient(1200px 800px at 20% 10%, #0f172a 0%, #0b1024 60%, #050817 100%);
  overflow: hidden;
}

/* Fullscreen canvas */
#canvas {
  position: fixed;
  inset: 0;
  display: block;
}

/* Glass HUD */
.hud {
  position: fixed;
  top: 16px;
  left: 16px;
  padding: 12px 14px;
  border-radius: 16px;
  backdrop-filter: blur(10px) saturate(120%);
  background: rgba(255, 255, 255, 0.06);
  box-shadow: 0 10px 30px rgba(0,0,0,0.35);
  border: 1px solid rgba(255,255,255,0.12);
  user-select: none;
  transition: transform 300ms ease, opacity 300ms ease;
  max-width: min(92vw, 420px);
}
.hud .title {
  font-size: 16px;
  letter-spacing: .3px;
  opacity: .9;
  margin-bottom: 6px;
}
.hud .mode { opacity: .9; margin-bottom: 6px; }
.hud .tips { opacity: .75; font-size: 12px; }

/* Footer */
.footer {
  position: fixed;
  bottom: 10px;
  right: 14px;
  opacity: .5;
  font-size: 12px;
  user-select: none;
}

/* Subtle entrance anim */
.hud { transform: translateY(-6px); opacity: 0; }
body.loaded .hud { transform: translateY(0); opacity: 1; }

/* Optional glowing vibe for particles */
.glow {
  filter: drop-shadow(0 0 12px rgba(120, 180, 255, 0.45));
}