html {
  background: #070708;
}

/* ═══ 深空星云背景 ═══ */
.bg-stars {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: 0;
  pointer-events: none;
  background-color: #05050a;
  background-image:
          radial-gradient(ellipse 70% 55% at 50% 30%,
              rgba(40,25,70,0.30) 0%,
              rgba(10,10,35,0.20) 40%,
              transparent 75%);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  will-change: transform;
  transform: translateZ(0);
}
/* 层1: 细小白色星 — 缓慢闪烁 */
.bg-stars::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background-image:
          radial-gradient(0.7px 0.7px at 63.8% 3.0%, rgba(255,255,255,0.33) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 22.6% 73.4%, rgba(255,255,255,0.45) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 88.8% 9.1%, rgba(255,255,255,0.38) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 3.4% 22.1%, rgba(255,255,255,0.40) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 3.1% 20.2%, rgba(255,255,255,0.44) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 54.4% 22.3%, rgba(255,255,255,0.43) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 80.6% 1.1%, rgba(255,255,255,0.49) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 69.6% 34.2%, rgba(255,255,255,0.30) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 95.3% 33.8%, rgba(255,255,255,0.28) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 10.1% 84.4%, rgba(255,255,255,0.43) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 80.4% 72.7%, rgba(255,255,255,0.41) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 96.8% 38.0%, rgba(255,255,255,0.42) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 82.6% 61.7%, rgba(255,255,255,0.51) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 57.7% 70.3%, rgba(255,255,255,0.26) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 23.1% 29.1%, rgba(255,255,255,0.27) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 23.5% 10.5%, rgba(255,255,255,0.33) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 63.4% 36.6%, rgba(255,255,255,0.36) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 21.2% 26.9%, rgba(255,255,255,0.53) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 64.7% 60.8%, rgba(255,255,255,0.30) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 72.7% 16.7%, rgba(255,255,255,0.36) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 98.5% 63.9%, rgba(255,255,255,0.42) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 68.3% 83.9%, rgba(255,255,255,0.48) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 23.2% 3.7%, rgba(255,255,255,0.34) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 27.0% 21.4%, rgba(255,255,255,0.53) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 87.3% 31.7%, rgba(255,255,255,0.45) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 39.7% 91.0%, rgba(255,255,255,0.39) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 26.7% 24.9%, rgba(255,255,255,0.42) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 26.5% 58.4%, rgba(255,255,255,0.52) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 40.0% 22.2%, rgba(255,255,255,0.55) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 50.9% 9.5%, rgba(255,255,255,0.26) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 11.4% 62.6%, rgba(255,255,255,0.49) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 42.3% 6.8%, rgba(255,255,255,0.36) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 99.1% 52.9%, rgba(255,255,255,0.54) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 85.7% 1.6%, rgba(255,255,255,0.47) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 68.0% 53.7%, rgba(255,255,255,0.33) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 64.0% 11.5%, rgba(255,255,255,0.38) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 45.4% 94.9%, rgba(255,255,255,0.51) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 26.6% 50.1%, rgba(255,255,255,0.30) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 90.9% 86.7%, rgba(255,255,255,0.34) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 63.8% 60.8%, rgba(255,255,255,0.30) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 76.0% 53.9%, rgba(255,255,255,0.48) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 53.0% 0.6%, rgba(255,255,255,0.35) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 2.4% 92.5%, rgba(255,255,255,0.51) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 82.8% 30.9%, rgba(255,255,255,0.27) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 87.4% 94.2%, rgba(255,255,255,0.28) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 48.6% 7.4%, rgba(255,255,255,0.48) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 76.3% 13.2%, rgba(255,255,255,0.39) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 54.9% 26.7%, rgba(255,255,255,0.51) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 42.4% 21.5%, rgba(255,255,255,0.41) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 72.8% 20.4%, rgba(255,255,255,0.34) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 99.0% 64.8%, rgba(255,255,255,0.38) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 51.7% 12.5%, rgba(255,255,255,0.32) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 34.0% 58.7%, rgba(255,255,255,0.32) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 22.3% 7.5%, rgba(255,255,255,0.44) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 23.2% 90.1%, rgba(255,255,255,0.51) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 7.5% 24.1%, rgba(255,255,255,0.45) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 21.7% 13.6%, rgba(255,255,255,0.53) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 57.0% 47.3%, rgba(255,255,255,0.49) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 80.4% 19.4%, rgba(255,255,255,0.28) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 43.2% 42.4%, rgba(255,255,255,0.39) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 72.7% 67.2%, rgba(255,255,255,0.55) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 10.2% 40.4%, rgba(255,255,255,0.35) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 85.8% 25.1%, rgba(255,255,255,0.31) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 44.9% 42.3%, rgba(255,255,255,0.33) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 25.2% 91.9%, rgba(255,255,255,0.38) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 85.8% 55.0%, rgba(255,255,255,0.27) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 99.4% 83.3%, rgba(255,255,255,0.54) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 92.2% 84.5%, rgba(255,255,255,0.30) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 48.6% 21.7%, rgba(255,255,255,0.37) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 6.3% 38.0%, rgba(255,255,255,0.55) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 26.8% 78.1%, rgba(255,255,255,0.39) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 42.4% 95.3%, rgba(255,255,255,0.55) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 55.5% 71.6%, rgba(255,255,255,0.30) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 29.9% 96.4%, rgba(255,255,255,0.42) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 54.2% 74.5%, rgba(255,255,255,0.27) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 58.3% 50.3%, rgba(255,255,255,0.51) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 16.1% 95.6%, rgba(255,255,255,0.27) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 18.9% 59.4%, rgba(255,255,255,0.45) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 23.8% 12.4%, rgba(255,255,255,0.52) 50%, transparent 50%),
          radial-gradient(0.7px 0.7px at 24.9% 59.4%, rgba(255,255,255,0.44) 50%, transparent 50%);
  background-size: 100% 100%;
  animation: star-twinkle-slow 5s ease-in-out infinite alternate;
}
/* 层2: 彩色中星 + 明亮大星 */
.bg-stars::after {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background-image:
          radial-gradient(2.5px 2.5px at 50.9% 9.9%, rgba(59,130,246,0.96) 50%, transparent 50%),
          radial-gradient(3px 3px at 85.9% 38.3%, rgba(248,113,113,0.89) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 96.8% 53.2%, rgba(244,114,182,0.74) 50%, transparent 50%),
          radial-gradient(3px 3px at 11.0% 38.2%, rgba(252,165,165,0.95) 50%, transparent 50%),
          radial-gradient(3px 3px at 43.9% 51.7%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 63.7% 3.5%, rgba(196,181,253,0.77) 50%, transparent 50%),
          radial-gradient(3px 3px at 11.9% 43.6%, rgba(248,113,113,0.70) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 62.5% 78.6%, rgba(129,140,248,0.88) 50%, transparent 50%),
          radial-gradient(3px 3px at 69.4% 34.3%, rgba(244,114,182,0.76) 50%, transparent 50%),
          radial-gradient(4px 4px at 7.9% 24.3%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(4px 4px at 22.0% 14.0%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 3.9% 22.4%, rgba(59,130,246,0.87) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 25.2% 56.0%, rgba(196,181,253,0.92) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 5.5% 23.3%, rgba(196,181,253,1.00) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 89.0% 40.1%, rgba(167,243,208,1.00) 50%, transparent 50%),
          radial-gradient(3px 3px at 25.3% 7.3%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(2px 2px at 8.7% 29.7%, rgba(252,165,165,0.87) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 83.5% 50.8%, rgba(167,243,208,0.75) 50%, transparent 50%),
          radial-gradient(2px 2px at 16.9% 35.8%, rgba(196,181,253,0.91) 50%, transparent 50%),
          radial-gradient(3px 3px at 1.7% 70.4%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 53.9% 77.3%, rgba(59,130,246,0.88) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 22.6% 58.7%, rgba(59,130,246,0.93) 50%, transparent 50%),
          radial-gradient(4px 4px at 23.4% 89.7%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(2px 2px at 38.4% 98.6%, rgba(196,181,253,0.99) 50%, transparent 50%),
          radial-gradient(3px 3px at 67.7% 12.2%, rgba(196,181,253,0.93) 50%, transparent 50%),
          radial-gradient(2px 2px at 73.2% 67.3%, rgba(250,204,21,0.88) 50%, transparent 50%),
          radial-gradient(3px 3px at 96.2% 75.7%, rgba(250,204,21,0.96) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 21.7% 93.4%, rgba(252,165,165,0.76) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 93.8% 17.2%, rgba(129,140,248,0.99) 50%, transparent 50%),
          radial-gradient(2px 2px at 23.4% 4.1%, rgba(252,165,165,0.82) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 60.7% 17.8%, rgba(167,243,208,0.75) 50%, transparent 50%),
          radial-gradient(2px 2px at 87.0% 93.8%, rgba(250,204,21,0.92) 50%, transparent 50%),
          radial-gradient(3px 3px at 58.7% 23.6%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(3.5px 3.5px at 80.1% 72.5%, rgba(250,204,21,0.99) 50%, transparent 50%),
          radial-gradient(2px 2px at 27.5% 91.7%, rgba(167,243,208,0.91) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 2.9% 92.1%, rgba(196,181,253,0.77) 50%, transparent 50%),
          radial-gradient(4px 4px at 70.9% 40.1%, rgba(255,255,255,0.95) 50%, transparent 50%),
          radial-gradient(2.5px 2.5px at 39.8% 90.6%, rgba(248,113,113,0.74) 50%, transparent 50%);
  background-size: 100% 100%;
  animation: star-twinkle-med 3s ease-in-out infinite alternate;
  animation-delay: -1.2s;
}
@keyframes star-twinkle-slow {
  0% { opacity: 0.5; }
  100% { opacity: 1; }
}
@keyframes star-twinkle-med {
  0% { opacity: 0.35; }
  100% { opacity: 1; }
}