style.css

@import  url(https://fonts.googleapis.com/css?family=Montserrat);

body{
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 70vh;
  font-family: Montserrat;
  background: #00000000;
}

.text-input{
    position: relative;
    margin-top: 50px;
}

input{
    display: inline-block;
    width: 300px;
    height: 40px;
    box-sizing: border-box;
    outline: none;
    border: 1px solid lightgray;
    border-radius: 3px;
    padding: 10px 10px 10px 100px;
    transition: all 0.1s ease-out;
}

input + label{
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    height: 40px;
    line-height: 40px;
    color: white;
    border-radius: 3px 0 0 3px;
    padding: 0 20px;
    background: rgb(0, 153, 204);
    transform: translateZ(0) translateX(0);
    transition: all 0.4s ease-in;
    transition-delay: 0s;
}

input:focus + label{
    opacity: 0.2;
    border-radius: 3px;
    background: rgb(204, 51, 255);
    transition: all 0.4s ease-out;
}

input:focus{
    padding: 10px;
    transition: all 0.3s ease-out;
    transition-delay: 0s;
}

a {
    top: 0;
    left: 0;
    bottom: 0;
    margin-top: 10px;
    height: 40px;
    line-height: 40px;
    color: white;
    border-radius: 3px 0 0 3px;
    padding: 10px;
    background: rgb(0, 153, 204);
    transition:all .3s ease;
}

.labelStretch{
    width: 260px;
}

a:hover{
    background: rgb(204, 51, 255);
    transition:all .3s ease;
}