.mask {
  /* background-color: rgba(0, 0, 0, .6); */
  background-color: rgba(255, 255, 255, .6);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 999;
}

.main {
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

text {
  font-weight: bolder;
}

@keyframes letter {
  0% {
    font-size: 30px;
  }

  50% {
    font-size: 40px;
  }

  100% {
    font-size: 30px;
  }
}

.letter {
  animation: letter 1s infinite;
  color: #fff;
}

.letter1 {
  animation-delay: 0s;
}

.letter2 {
  animation-delay: -0.9s;
}

.letter3 {
  animation-delay: -0.8s;
}

.letter4 {
  animation-delay: -0.7s;
}

.letter5 {
  animation-delay: -0.6s;
}

.letter6 {
  animation-delay: -0.5s;
}

.letter7 {
  animation-delay: -0.4s;
}

.letter8 {
  animation-delay: -0.3s;
}

.letter9 {
  animation-delay: -0.2s;
}

.letter10 {
  animation-delay: -0.1s;
}