index.html

<!DOCTYPE html>
<!-- Created By Code With Sunny -->
<html lang="en" dir="ltr">
  <head>
    <meta charset="utf-8">
    
    <link rel="stylesheet" href="style.css">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
  </head>
  <body>
    <div class="wrapper">
      <div class="title-text">
        <div class="title signin">
Login Form</div>
<div class="title signup">
Signup Form</div>
</div>
<div class="form-container">
        <div class="slide-controls">
          <input type="radio" name="slide" id="signin" checked>
          <input type="radio" name="slide" id="signup">
          <label for="signin" class="slide signin">Sign In</label>
          <label for="signup" class="slide signup">Sign Up</label>
          <div class="slider-tab">
</div>
</div>
<div class="form-inner">
          <form action="#" class="signin">
            <div class="field">
              <input type="text" placeholder="Email Address" required>
            </div>
<div class="field">
              <input type="password" placeholder="Password" required>
            </div>
<div class="pass-link">
<a href="#">Forgot password?</a></div>
<div class="field btn">
              <div class="btn-layer">
</div>
<input type="submit" value="signin">
            </div>
<div class="signup-link">
Not a Register? <a href="">Signup Now</a></div>
</form>
<form action="#" class="signup">
            <div class="field">
              <input type="text" placeholder="Email Address" required>
            </div>
<div class="field">
              <input type="password" placeholder="Password" required>
            </div>
<div class="field">
              <input type="password" placeholder="Confirm password" required>
            </div>
<div class="field btn">
              <div class="btn-layer">
</div>
<input type="submit" value="Signup">
            </div>
</form>
</div>
</div>
</div>
<script>
      const signinText = document.querySelector(".title-text .signin");
      const signinForm = document.querySelector("form.signin");
      const signinBtn = document.querySelector("label.signin");
      const signupBtn = document.querySelector("label.signup");
      const signupLink = document.querySelector("form .signup-link a");
      signupBtn.onclick = (()=>{
        signinForm.style.marginLeft = "-50%";
        signinText.style.marginLeft = "-50%";
      });
      signinBtn.onclick = (()=>{
        signinForm.style.marginLeft = "0%";
        signinText.style.marginLeft = "0%";
      });
      signupLink.onclick = (()=>{
        signupBtn.click();
        return false;
      });
    </script>

  </body>
</html>

<!-- Created By Code With Sunny -->

style.css


@import url('https://fonts.googleapis.com/css?family=Poppins:400,500,600,700&display=swap');
*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}
html,body{
  display: grid;
  height: 100%;
  width: 100%;
  place-items: center;
  background: -webkit-linear-gradient(left, #BD3FAA, #6343BC );
}
::selection{
  background: #ffaadd;
  color: #fff;
}
.wrapper{
  overflow: hidden;
  max-width: 390px;
  background: #fff;
  padding: 30px;
  border-radius: 5px;
  box-shadow: 0px 15px 20px rgba(0,0,0,0.1);
}
.wrapper .title-text{
  display: flex;
  width: 200%;
}
.wrapper .title{
  width: 50%;
  font-size: 35px;
  font-weight: 600;
  text-align: center;
  transition: all 0.6s cubic-bezier(0.68,-0.55,0.265,1.55);
}
.wrapper .slide-controls{
  position: relative;
  display: flex;
  height: 50px;
  width: 100%;
  overflow: hidden;
  margin: 30px 0 10px 0;
  justify-content: space-between;
  border: 1px solid lightgrey;
  border-radius: 5px;
}
.slide-controls .slide{
  height: 100%;
  width: 100%;
  color: #000;
  font-size: 18px;
  font-weight: 500;
  text-align: center;
  line-height: 48px;
  cursor: pointer;
  z-index: 1;
  transition: all 0.6s ease;
}
.slide-controls label.signup{
  color: #000;
}
.slide-controls .slider-tab{
  position: absolute;
  height: 100%;
  width: 50%;
  left: 0;
  z-index: 0;
  border-radius: 5px;
  background: -webkit-linear-gradient(left, #a445b2, #fa4299);
  transition: all 0.6s cubic-bezier(0.68,-0.55,0.265,1.55);
}
input[type="radio"]{
  display: none;
}
#signup:checked ~ .slider-tab{
  left: 50%;
}
#signup:checked ~ label.signup{
  color: #fff;
  cursor: default;
  user-select: none;
}
#signup:checked ~ label.signin{
  color: #000;
}
#signin:checked ~ label.signup{
  color: #000;
}
#signin:checked ~ label.signin{
  cursor: default;
  user-select: none;
}
.wrapper .form-container{
  width: 100%;
  overflow: hidden;
}
.form-container .form-inner{
  display: flex;
  width: 200%;
}
.form-container .form-inner form{
  width: 50%;
  transition: all 0.6s cubic-bezier(0.68,-0.55,0.265,1.55);
}
.form-inner form .field{
  height: 50px;
  width: 100%;
  margin-top: 20px;
}
.form-inner form .field input{
  height: 100%;
  width: 100%;
  outline: none;
  padding-left: 15px;
  border-radius: 5px;
  border: 1px solid lightgrey;
  border-bottom-width: 2px;
  font-size: 17px;
  transition: all 0.3s ease;
}
.form-inner form .field input:focus{
  border-color: #fc83bb;
  
}
.form-inner form .field input::placeholder{
  color: #999;
  transition: all 0.3s ease;
}
form .field input:focus::placeholder{
  color: #b3b3b3;
}
.form-inner form .pass-link{
  margin-top: 5px;
}
.form-inner form .signup-link{
  text-align: center;
  margin-top: 30px;
}
.form-inner form .pass-link a,
.form-inner form .signup-link a{
  color: #fa4299;
  text-decoration: none;
}
.form-inner form .pass-link a:hover,
.form-inner form .signup-link a:hover{
  text-decoration: underline;
}
form .btn{
  height: 50px;
  width: 100%;
  border-radius: 5px;
  position: relative;
  overflow: hidden;
}
form .btn .btn-layer{
  height: 100%;
  width: 300%;
  position: absolute;
  left: -100%;
  background: -webkit-linear-gradient(right, #a445b2, #fa4299, #a445b2, #fa4299);
  border-radius: 5px;
  transition: all 0.4s ease;;
}
form .btn:hover .btn-layer{
  left: 0;
}
form .btn input[type="submit"]{
  height: 100%;
  width: 100%;
  z-index: 1;
  position: relative;
  background: none;
  border: none;
  color: #fff;
  padding-left: 0;
  border-radius: 5px;
  font-size: 20px;
  font-weight: 500;
  cursor: pointer;
}/* Created By Code With Sunny*/