小编Tik*_*iko的帖子

.input {
  display: flex;
  flex-direction: column;
  border: 1px solid #000;
  height: 50px;
  justify-content: flex-end;
}

.input > * {
  padding: 5px;
}

#login {
  visibility: hidden;
  height: 0px;
  transition: .2s
}

#login:active {
  visibility: visible;
  height: 10px;
}

<div class="input">
  <label for="login" id="login1">Login</label>
  <input type="text" id="login">  
</div>