<section>
  
  <div class="box">
    
    <div class="square" style="--i:0;"></div>
    <div class="square" style="--i:1;"></div>
    <div class="square" style="--i:2;"></div>
    <div class="square" style="--i:3;"></div>
    <div class="square" style="--i:4;"></div>
    <div class="square" style="--i:5;"></div>
    
   <div class="container"> 
    <div class="form"> 
      <h2>LOGIN to CodePen</h2>
      <form action="">
        <div class="inputBx">
          <input type="text" required="required">
          <span>Login</span>
          <i class="fas fa-user-circle"></i>
        </div>
        <div class="inputBx password">
          <input id="password-input" type="password" name="password" required="required">
          <span>Password</span>
          <a href="#" class="password-control" onclick="return show_hide_password(this);"></a>
          <i class="fas fa-key"></i>
        </div>
        <label class="remember"><input type="checkbox">
          Remember</label>
        <div class="inputBx">
          <input type="submit" value="Log in" disabled> 
        </div>
      </form>
      <p>Forgot password? <a href="#">Click Here</a></p>
      <p>Don't have an account <a href="#">Sign up</a></p>
    </div>
  </div>
    
  </div>
</section>
@import url('https://fonts.googleapis.com/css2?family=El+Messiri:wght@700&display=swap');

* {
  margin: 0;
  padding: 0;
  font-family: 'El Messiri', sans-serif;
}

body {
  background: #031323;
  overflow: hidden;
}

.fas {
  width: 32px;
}

section {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
  background-size: 400% 400%;
  animation: gradient 10s ease infinite;
}

@keyframes gradient {
    0% {
      background-position: 0% 50%;
      }
    50% {
      background-position: 100% 50%;
      }
    100% {
      background-position: 0% 50%;
      }
}

.box {
  position: relative;
  
  .square {
    position: absolute;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(5px);
    box-shadow: 0 25px 45px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 15px;
    animation: square 10s linear infinite;
    animation-delay: calc(-1s * var(--i));
  }
  
  @keyframes square {
    0%,100% {
      transform: translateY(-20px);
    }
    
    50% {
      transform: translateY(20px);
    }
  }
  
  .square:nth-child(1) {
    width: 100px;
    height: 100px;
    top: -15px;
    right: -45px;
  }
  
  .square:nth-child(2) {
    width: 150px;
    height: 150px;
    top: 105px;
    left: -125px;
    z-index: 2;
  }
  
  .square:nth-child(3) {
    width: 60px;
    height: 60px;
    bottom: 85px;
    right: -45px;
    z-index: 2;
  }
  
  .square:nth-child(4) {
    width: 50px;
    height: 50px;
    bottom: 35px;
    left: -95px;
  }
  
  .square:nth-child(5) {
    width: 50px;
    height: 50px;
    top: -15px;
    left: -25px;
  }
  
  .square:nth-child(6) {
    width: 85px;
    height: 85px;
    top: 165px;
    right: -155px;
    z-index: 2;
  }
}

.container {
  position: relative;
  padding: 50px;
  width: 260px;
  min-height: 380px;
  display: flex;
  justify-content: center;
  align-items: center;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(5px);
  border-radius: 10px;
  box-shadow: 0 25px 45px rgba(0, 0, 0, 0.2);
}

.container::after {
  content: '';
  position: absolute;
  top: 5px;
  right: 5px;
  bottom: 5px;
  left: 5px;
  border-radius: 5px;
  pointer-events: none;
  background: linear-gradient( to bottom, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0.1) 2%
  );
}

.form {
  position: relative;
  width: 100%;
  height: 100%;

   h2 {
    color: #fff;
    letter-spacing: 2px;
    margin-bottom: 30px;
  }

  .inputBx {
    position: relative;
    width: 100%;
    margin-bottom: 20px;
    
    input {
      width: 80%;
      outline: none;
      border: none;
      border: 1px solid rgba(255, 255, 255, 0.2);
      background: rgba(255, 255, 255, 0.2);
      padding: 8px 10px;
      padding-left: 40px;
      border-radius: 15px;
      color: #fff;
      font-size: 16px;
      box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    }
    
    .password-control {
      position: absolute;
      top: 11px;
      right: 10px;
      display: inline-block;
      width: 20px;
      height: 20px;
      background: url(https://snipp.ru/demo/495/view.svg) 0 0 no-repeat;
      transition: 0.5s;
}
        
      .view {
         background: url(https://snipp.ru/demo/495/no-view.svg) 0 0 no-repeat;
        transition: 0.5s;
  }

    
  
    .fas {
      position: absolute;
      top: 13px;
      left: 13px;
    }
    
    input[type="submit"] {
      background: #fff;
      color: #111;
      max-width: 100px;
      padding: 8px 10px;
      box-shadow: none;
      letter-spacing: 1px;
      cursor: pointer;
      transition: 1.5s;
    }
    
    input[type="submit"]:hover {
      background: linear-gradient(115deg, 
        rgba(0,0,0,0.10), 
        rgba(255,255,255,0.25));
      color: #fff;
      transition: .5s;
    }
    
    input::placeholder {
      color: #fff;
    }
    
    span {
        position: absolute;
        left: 30px;
        padding: 10px;
        display: inline-block;
        color: #fff;
        transition: .5s;
        pointer-events: none;
      }
    
    input:focus ~ span,
    input:valid ~ span {
      transform: translateX(-30px) translateY(-25px);
      font-size: 12px;
    }
  }
  
  p {
    color: #fff;
    font-size: 15px;
    margin-top: 5px;
  
    a {
      color: #fff;
    }
    
    a:hover {
      background-color: #000;
      background-image: linear-gradient(to right, #434343 0%, black 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
  }
}

.remember {
  position: relative;
  display: inline-block;
  color: #fff;
  margin-bottom: 10px;
  cursor: pointer;
}
View Compiled
function show_hide_password(target){
	var input = document.getElementById('password-input');
	if (input.getAttribute('type') == 'password') {
		target.classList.add('view');
		input.setAttribute('type', 'text');
	} else {
		target.classList.remove('view');
		input.setAttribute('type', 'password');
	}
	return false;
}
Run Pen

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.1/css/all.min.css

External JavaScript

This Pen doesn't use any external JavaScript resources.