*{
  box-sizing:border-box;
  margin:0;
  padding:0;
}
body {
  height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  background-color: #e8e8e8;
  font-family:arial;
}
.input {
  color: black;
  font: 1em/1.5 Hind, sans-serif;
}

form, .input, .caret {
  margin: auto;
}

form {
  position: relative;
  width: 100%;
  max-width: 17em;
}

.input, .caret {
  display: block;
  transition: all calc(1s * 0.5) linear;
}

.input {
  background: transparent;
  border-radius: 50%;
  box-shadow: 0 0 0 0.25em inset;
  caret-color: #255ff4;
  width: 2em;
  height: 2em;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
}

.input:focus, .input:valid {
  background: powderblue;
  border-radius: 0.25em;
  box-shadow: none;
  padding: 0.75em 1em;
  transition-duration: calc(1s * 0.25);
  transition-delay: calc(1s * 0.25);
  width: 100%;
  height: 3em;
}

.input:focus {
  animation: showCaret 1s steps(1);
  outline: transparent;
}

.input:focus + .caret, .input:valid + .caret {
  animation: handleToCaret 1s linear;
  background: transparent;
  width: 1px;
  height: 1.5em;
  transform: translate(0,-1em) rotate(-180deg) translate(7.5em,-0.25em);
}

.input::-webkit-search-decoration {
  -webkit-appearance: none;
}

label {
  color: #e3e4e8;
  overflow: hidden;
  position: absolute;
  width: 0;
  height: 0;
}

.caret {
  background: black;
  border-radius: 0 0 0.125em 0.125em;
  margin-bottom: -0.6em;
  width: 0.25em;
  height: 1em;
  transform: translate(0,-1em) rotate(-45deg) translate(0,0.875em);
  transform-origin: 50% 0;
}

/* Animations */
@keyframes showCaret {
  from {
    caret-color: transparent;
  }

  to {
    caret-color: #255ff4;
  }
}

@keyframes handleToCaret {
  from {
    background: currentColor;
    width: 0.25em;
    height: 1em;
    transform: translate(0,-1em) rotate(-45deg) translate(0,0.875em);
  }

  25% {
    background: currentColor;
    width: 0.25em;
    height: 1em;
    transform: translate(0,-1em) rotate(-180deg) translate(0,0.875em);
  }

  50%, 62.5% {
    background: #255ff4;
    width: 1px;
    height: 1.5em;
    transform: translate(0,-1em) rotate(-180deg) translate(7.5em,2.5em);
  }

  75%, 99% {
    background: #255ff4;
    width: 1px;
    height: 1.5em;
    transform: translate(0,-1em) rotate(-180deg) translate(7.5em,-0.25em);
  }

  87.5% {
    background: #255ff4;
    width: 1px;
    height: 1.5em;
    transform: translate(0,-1em) rotate(-180deg) translate(7.5em,0.125em);
  }

  to {
    background: transparent;
    width: 1px;
    height: 1.5em;
    transform: translate(0,-1em) rotate(-180deg) translate(7.5em,-0.25em);
  }
}