/* 添加B站风格渐变背景动画 */
.main-banner {
  position: relative;
  overflow: hidden;
  background: linear-gradient(45deg, #ff6b6b, #4ecdc4, #45b7d1, #96f2d7);
  background-size: 400% 400%;
  animation: gradientFlow 15s ease infinite;
}

@keyframes gradientFlow {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.main-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  right: -50%;
  bottom: -50%;
  background: linear-gradient(45deg, transparent 35%, rgba(255,255,255,0.1) 50%, transparent 65%);
  animation: lightStreak 8s linear infinite;
  transform: rotate(30deg);
}

@keyframes lightStreak {
  from { transform: translateY(-100%) rotate(30deg); }
  to { transform: translateY(100%) rotate(30deg); }
}