searchbar.css

* {
  transition: 0.25s all;
}

.icon {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 2rem;
  height: 2rem;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  background: transparent;
  color: tomato;
}

.search-bar {
  display: flex;
  background: #ffffff;
  border: 2px solid tomato;
  border-radius: 2rem;
  height: 2rem;
  padding: 0.2rem;
  width: 2rem;
}
.search-bar:focus-within {
  width: 20rem;
}
.search-bar:focus-within .icon {
  background: tomato;
  color: #ffffff;
}

.input {
  border: none;
  outline: none;
  line-height: 1.75rem;
  background: transparent;
  z-index: 1;
  cursor: pointer;
  width: 2rem;
  margin-right: -2rem;
  padding: 0;
  flex-grow: 0;
  color: transparent;
}
.input::placeholder {
  visibility: hidden;
}
.input:focus-within {
  cursor: text;
  width: auto;
  margin-right: 0;
  padding: 0 0.75rem;
  flex-grow: 1;
  color: #fbda90;
}
.input:focus-within::placeholder {
  visibility: visible;
}