.input-container {
  position: relative;
  margin: 50px auto;
  width: 80%;
}

.input-container input {
  font-size: 20px;
  width: 100%;
  border: none;
  border-bottom: 2px solid #ccc;
  padding: 5px 0;
  background-color: transparent;
  outline: none;
}

.input-container .label {
  position: absolute;
  top: 0;
  left: 0;
  color: #ccc;
  transition: all 0.3s ease;
  pointer-events: none;
}

.input-container input:focus ~ .label,
.input-container input:valid ~ .label {
  top: -20px;
  font-size: 16px;
  color: #59B4C3;
}

.input-container .underline {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  width: 100%;
  background-color: #59B4C3;
  transform: scaleX(0);
  transition: all 0.3s ease;
}

.input-container input:focus ~ .underline,
.input-container input:valid ~ .underline {
  transform: scaleX(1);
}


.btn-submit {
  font-size: 13px;
  letter-spacing: 2px;
  text-transform: uppercase;
  display: inline-block;
  text-align: center;
  font-weight: bold;
  padding: 0.7em 2em;
  border: 3px solid #59B4C3;
  border-radius: 10px;
  position: relative;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.16), 0 3px 6px rgba(0, 0, 0, 0.1);
  color: #59B4C3;
  text-decoration: none;
  transition: 0.3s ease all;
  z-index: 1;
}

.btn-submit:before {
  transition: 0.5s all ease;
  position: absolute;
  top: 0;
  left: 50%;
  right: 50%;
  bottom: 0;
  opacity: 0;
  content: '';
  background-color: #59B4C3;
  border-radius: 10px;
  z-index: -1;
}

.btn-submit:hover, .btn-submit:focus {
  color: white;
  border-radius: 10px;
}

.btn-submit:hover:before, .btn-submit:focus:before {
  transition: 0.5s all ease;
  left: 0;
  right: 0;
  opacity: 1;
}

.btn-submit:active {
  transform: scale(0.9);
  border-radius: 10px;
}

@media only screen and (max-width: 500px) {

  .input-container {
      position: relative;
      margin: 50px auto;
      width: 100%;
  }

}

body {
  text-align: center;
  margin: 0px;
  padding: 0px;
  height: 100%;
  color: #fff;
  font-family: sans-serif;
  background: linear-gradient(-45deg, #211C6A, #59B4C3, #74E291, #EFF396);
  background-size: 400% 400%;
  -webkit-animation: Gradient 15s ease infinite;
  -moz-animation: Gradient 15s ease infinite;
  animation: Gradient 15s ease infinite;
}

@-webkit-keyframes Gradient {
  0% {
      background-position: 0% 50%
  }

  50% {
      background-position: 100% 50%
  }

  100% {
      background-position: 0% 50%
  }
}

@-moz-keyframes Gradient {
  0% {
      background-position: 0% 50%
  }

  50% {
      background-position: 100% 50%
  }

  100% {
      background-position: 0% 50%
  }
}

@keyframes Gradient {
  0% {
      background-position: 0% 50%
  }

  50% {
      background-position: 100% 50%
  }

  100% {
      background-position: 0% 50%
  }
}

/* hide arrow input number */
/* Chrome, Safari, Edge, Opera */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* Firefox */
input[type=number] {
  -moz-appearance: textfield;
}