<body>

  <div class="container">
    <div class="backbox">
      <div class="loginMsg">
        <div class="textcontent">
          <p class="title">Don't have an account?</p>
          <p>Sign up to save all your graph.</p>
          <button id="switch1">Sign Up</button>
        </div>
      </div>
      <div class="signupMsg visibility">
        <div class="textcontent">
          <p class="title">Have an account?</p>
          <p>Log in to see all your collection.</p>
          <button id="switch2">LOG IN</button>
        </div>
      </div>
    </div>
    <!-- backbox -->

    <div class="frontbox">
      <div class="login">
        <h2>LOG IN</h2>
        <div class="inputbox">
          <input type="text" name="email" placeholder="  EMAIL">
          <input type="password" name="password" placeholder="  PASSWORD">
        </div>
        <p>FORGET PASSWORD?</p>
        <button>LOG IN</button>
      </div>

      <div class="signup hide">
        <h2>SIGN UP</h2>
        <div class="inputbox">
          <input type="text" name="fullname" placeholder="  FULLNAME">
          <input type="text" name="email" placeholder="  EMAIL">
          <input type="password" name="password" placeholder="  PASSWORD">
        </div>
        <button>SIGN UP</button>
      </div>

    </div>
    <!-- frontbox -->
  </div>
</body>

</html>
body{
  background-color: #A8A8A8;
  font-family: 'Roboto', sans-serif;
}

.container{
  /*border:1px solid white;*/
  width: 600px;
  height: 350px;
  position: absolute;
  top:50%;
  left:50%;
  transform: translate(-50%, -50%);
  display: inline-flex; 
}
.backbox{  
  background-color: #404040;
  width: 100%;
  height: 80%;
  position: absolute;
  transform: translate(0,-50%);
  top:50%;
  display: inline-flex;
}

.frontbox{
  background-color: white;
  border-radius: 20px;
  height: 100%;
  width: 50%;
  z-index: 10;
  position: absolute;
  right:0;
  margin-right: 3%;
  margin-left: 3%;
  transition: right .8s ease-in-out;
}

.moving{
  right:45%;
}

.loginMsg, .signupMsg{
  width: 50%;
  height: 100%;
  font-size: 15px;
  box-sizing: border-box;
}

.loginMsg .title,
.signupMsg .title{
  font-weight: 300;
  font-size: 23px;
}

.loginMsg p,
.signupMsg p {
  font-weight: 100;
}

.textcontent{
  color:white;
  margin-top:65px;
  margin-left: 12%;
}

.loginMsg button,
.signupMsg button {
  background-color: #404040;
  border: 2px solid white;
  border-radius: 10px;
  color:white;
  font-size: 12px;
  box-sizing: content-box;
  font-weight: 300;
  padding:10px;
  margin-top: 20px;
}

/* front box content*/
.login, .signup{
  padding: 20px;
  text-align: center;
}

.login h2,
.signup h2 {
  color: #35B729;
  font-size:22px;
}

.inputbox{
  margin-top:30px; 
}
.login input, 
.signup input {
  display: block;
  width: 100%;
  height: 40px;
  background-color: #f2f2f2;
  border: none;
  margin-bottom:20px;
  font-size: 12px;
}

.login button,
.signup button{
  background-color: #35B729;
  border: none;
  color:white;
  font-size: 12px;
  font-weight: 300;
  box-sizing: content-box;
  padding:10px;
  border-radius: 10px;
  width: 60px;
  position: absolute;
  right:30px;
  bottom: 30px;
  cursor: pointer;
}

/* Fade In & Out*/
.login p {
  cursor: pointer;
  color:#404040;
  font-size:15px;
}

.loginMsg, .signupMsg{
  /*opacity: 1;*/
  transition: opacity .8s ease-in-out;
}

.visibility{
  opacity: 0;
}

.hide{
  display: none;
}

var $loginMsg = $('.loginMsg'),
  $login = $('.login'),
  $signupMsg = $('.signupMsg'),
  $signup = $('.signup'),
  $frontbox = $('.frontbox');

$('#switch1').on('click', function() {
  $loginMsg.toggleClass("visibility");
  $frontbox.addClass("moving");
  $signupMsg.toggleClass("visibility");

  $signup.toggleClass('hide');
  $login.toggleClass('hide');
})

$('#switch2').on('click', function() {
  $loginMsg.toggleClass("visibility");
  $frontbox.removeClass("moving");
  $signupMsg.toggleClass("visibility");

  $signup.toggleClass('hide');
  $login.toggleClass('hide');
})

setTimeout(function(){
  $('#switch1').click()
},1000)

setTimeout(function(){
  $('#switch2').click()
},3000)

External CSS

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External JavaScript

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