.fab{
  position:fixed;right:36rpx;bottom:calc(190rpx + env(safe-area-inset-bottom));
  width:116rpx;height:116rpx;border-radius:44rpx;
  background:linear-gradient(135deg,#78A6E8,#9FC0F5);
  color:#fff;font-weight:900;font-size:40rpx;
  display:flex;align-items:center;justify-content:center;
  box-shadow:0 28rpx 60rpx rgba(120,166,232,.32);
  z-index:60;
}
.fab:active{transform:scale(.96)}