@import url('https://fonts.googleapis.com/css?family=Muli&display=swap');

:root {
  --btn-color: lightblue;
}

body {
  font-family: 'Muli', sans-serif;
  margin: 0;
  height: 100vh;
  background-color: #5680b1;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
}

.app {
  background-color: rgba(0, 0, 0, 0.4);
  padding: 20px 40px;
  border-radius: 5px;
}

.form-item {
  width: 300px;
  margin: 20px 0 40px;
  position: relative;
}

.btn {
  cursor: pointer;
  display: inline-block;
  width: 100%;
  background: var(--btn-color);
  padding: 15px;
  font-family: inherit;
  font-size: 16px;
  border: 0;
  border-radius: 5px;
}

h1 {
  text-align: center;
}

.text {
  margin-top: 30px;
}

a {
  color: var(--btn-color);
  text-decoration: none;
}

.form-item input {
  border: none;
  outline: none;
  font-size: 18px;
  background-color: transparent;
  color: #fff;
  border-bottom: 2px solid #fff;
  width: 100%;
  padding: 15px 0;
}

label {
  position: absolute;
  left: 0;
  bottom: 20px;
}

.form-item label span {
  display: inline-block;
  transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* input:focus ~ label {
  bottom: 50px;
} */

input:focus ~ label span,
input:valid ~ label span {
  color: var(--btn-color);
  transform: translateY(-30px);
}