* {
  box-sizing: border-box;
}

body {
  background-color: #212121;
  font-family: "Segoe UI", sans-serif;
  margin: 0;
  overflow: hidden;
  height: 100vh;
  padding: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
}

h1 {
  color: aliceblue;
  text-align: center;
}

label,
p {
  color: aliceblue;
}

.btn {
  position: relative;
  background: linear-gradient(to bottom, #e81cff8d, #40c9ff69);
  padding: 15px;
  width: 80%;
  color: #fff;
  border: 1px #fff;
  border-radius: 7px;
  font-family: "Segoe UI", sans-serif;
  font-weight: bold;
  font-size: 18px;
  animation: button-shimmer 2s infinite;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

@keyframes button-shimmer {
  0% {
    background-position: left top;
  }

  100% {
    background-position: right bottom;
  }
}

@keyframes button-particles {
  0% {
    background-position: left top;
  }

  100% {
    background-position: right bottom;
  }
}

.btn:hover {
  background: linear-gradient(to bottom, #e81cff, #40c9ff);
  animation: button-particles 1s ease-in-out infinite;
  transform: translateY(-6px);
  scale: 0.9;
  transition:
    transform
    550ms
    cubic-bezier(0.3, 0.7, 0.4, 1.5);
}

.btn:active {
  transform: scale(0.95);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

a {
  text-decoration: none;
  color: #fff;
}

.container {
  background:
    linear-gradient(#000, #000) padding-box,
    linear-gradient(145deg, transparent 35%, #e81cff, #40c9ff) border-box;
  padding: 20px 40px;
  border-radius: 3%;
  display: flex;
  flex-direction: column;
  background-size: 200% 100%;
  animation: gradient 5s ease infinite;
  border: 2px solid transparent;
}

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

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

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

.form-control {
  position: relative;
  margin: 20px;
  width: 80%;
}

.form-control input {
  background-color: transparent;
  border: 0;
  border-bottom: 2px #ffffffd4 solid;
  display: block;
  width: 100%;
  font-size: 18px;
  color: #fff;
}

.form-control input:focus,
.form-control input:valid {
  outline: 0;
  border-bottom-color: #ffffffd4;
}

.form-control label {
  position: absolute;
  top: 15px;
  left: 0;
  color: #717171;
}

.form-control label span {
  display: inline-block;
  font-size: 18px;
  min-width: 5px;
  transition: 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
}

.form-control input:focus + label span,
.form-control input:valid + label span {
  color: #ffffffb7;
  transform: translateY(-30px);
}