.button-container-1 {
  position: relative;
  width: 100px;
  height: 50px;
  margin-left: auto;
  margin-right: auto;
  margin-top: 6vh;
  overflow: hidden;
  border: 1px solid;
  font-family: 'Lato', sans-serif;
  font-weight: 300;
  font-size: 20px;
  transition: 0.5s;
  letter-spacing: 1px;
  border-radius: 8px;
}

.button-container-1 button {
  width: 101%;
  height: 100%;
  font-family: 'Lato', sans-serif;
  font-weight: bold;
  font-size: 11px;
  letter-spacing: 1px;
  background: #000;
  -webkit-mask: url("https://raw.githubusercontent.com/robin-dela/css-mask-animation/master/img/nature-sprite.png");
  mask: url("https://raw.githubusercontent.com/robin-dela/css-mask-animation/master/img/nature-sprite.png");
  -webkit-mask-size: 2300% 100%;
  mask-size: 2300% 100%;
  border: none;
  color: #fff;
  cursor: pointer;
  -webkit-animation: ani2 0.7s steps(22) forwards;
  animation: ani2 0.7s steps(22) forwards;
}

.button-container-1 button:hover {
  -webkit-animation: ani 0.7s steps(22) forwards;
  animation: ani 0.7s steps(22) forwards;
}

.button-container-2 {
  position: relative;
  width: 100px;
  height: 50px;
  margin-left: auto;
  margin-right: auto;
  margin-top: 7vh;
  overflow: hidden;
  border: 1px solid #000;
  font-family: 'Lato', sans-serif;
  font-weight: 300;
  transition: 0.5s;
  letter-spacing: 1px;
  border-radius: 8px;
}

.button-container-2 button {
  width: 101%;
  height: 100%;
  font-family: 'Lato', sans-serif;
  font-weight: bold;
  font-size: 11px;
  letter-spacing: 1px;
  background: #000;
  -webkit-mask: url("https://raw.githubusercontent.com/robin-dela/css-mask-animation/master/img/urban-sprite.png");
  mask: url("https://raw.githubusercontent.com/robin-dela/css-mask-animation/master/img/urban-sprite.png");
  -webkit-mask-size: 3000% 100%;
  mask-size: 3000% 100%;
  border: none;
  color: #fff;
  cursor: pointer;
  -webkit-animation: ani2 0.7s steps(29) forwards;
  animation: ani2 0.7s steps(29) forwards;
}

.button-container-2 button:hover {
  -webkit-animation: ani 0.7s steps(29) forwards;
  animation: ani 0.7s steps(29) forwards;
}

.mas {
  position: absolute;
  color: #000;
  text-align: center;
  width: 101%;
  font-family: 'Lato', sans-serif;
  font-weight: bold;
  font-size: 11px;
  margin-top: 17px;
  overflow: hidden;
}

@-webkit-keyframes ani {
  from {
    -webkit-mask-position: 0 0;
    mask-position: 0 0;
  }
  to {
    -webkit-mask-position: 100% 0;
    mask-position: 100% 0;
  }
}

@keyframes ani {
  from {
    -webkit-mask-position: 0 0;
    mask-position: 0 0;
  }
  to {
    -webkit-mask-position: 100% 0;
    mask-position: 100% 0;
  }
}

@-webkit-keyframes ani2 {
  from {
    -webkit-mask-position: 100% 0;
    mask-position: 100% 0;
  }
  to {
    -webkit-mask-position: 0 0;
    mask-position: 0 0;
  }
}

@keyframes ani2 {
  from {
    -webkit-mask-position: 100% 0;
    mask-position: 100% 0;
  }
  to {
    -webkit-mask-position: 0 0;
    mask-position: 0 0;
  }
}

a {
  color: #00ff95;
}

.button-container-3 {
  position: relative;
  width: 100px;
  height: 50px;
  margin-left: auto;
  margin-right: auto;
  margin-top: 8vh;
  overflow: hidden;
  border: 1px solid #000;
  font-family: 'Lato', sans-serif;
  font-weight: 300;
  transition: 0.5s;
  letter-spacing: 1px;
  border-radius: 8px;
}

.button-container-3 button {
  width: 101%;
  height: 100%;
  font-family: 'Lato', sans-serif;
  font-weight: bold;
  font-size: 11px;
  letter-spacing: 1px;
  background: #000;
  -webkit-mask: url("https://raw.githubusercontent.com/pizza3/asset/master/natureSmaller.png");
  mask: url("https://raw.githubusercontent.com/pizza3/asset/master/natureSmaller.png");
  -webkit-mask-size: 7100% 100%;
  mask-size: 7100% 100%;
  border: none;
  color: #fff;
  cursor: pointer;
  -webkit-animation: ani2 0.7s steps(70) forwards;
  animation: ani2 0.7s steps(70) forwards;
}

.button-container-3 button:hover {
  -webkit-animation: ani 0.7s steps(70) forwards;
  animation: ani 0.7s steps(70) forwards;
}