<head>
  <link href="https://fonts.googleapis.com/css2?family=Oswald&display=swap" rel="stylesheet">
 <link href="https://fonts.googleapis.com/css2?family=Lato&display=swap" rel="stylesheet">
    <script src="https://kit.fontawesome.com/a076d05399.js"></script>
  </head>

  <body>
    <input type="checkbox" id="active">
    <label for="active" class="menu-btn"><i class="fas fa-bars"></i></label>
    <div class="wrapper">
      <ul>
<li><a href="#">Home</a></li>
<li><a href="#">About</a></li>
<li><a href="#">Services</a></li>
<li><a href="#">Gallery</a></li>
<li><a href="#">Feedback</a></li>
</ul>
</div>
<div class="content">
      <div class="title">
Fullscreen Overlay Navigation Bar</div>
<p>
with HTML & CSS Neon Effect</p>
</div>
</body>


*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Lato', sans-serif;
  font-family: 'Oswald', sans-serif;
}
.wrapper{
  position: fixed;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  /*background: linear-gradient(-135deg, #c850c0, #4158d0);*/
  /* background: linear-gradient(375deg, #1cc7d0, #2ede98); */
 /* background: linear-gradient(-45deg, #e3eefe 0%, #efddfb 100%);*/
  /* clip-path: circle(25px at calc(0% + 45px) 45px); */
  background: #000;
  clip-path: circle(25px at calc(100% - 45px) 45px);
  transition: all 0.3s ease-in-out;
}
#active:checked ~ .wrapper{
  clip-path: circle(75%);
}
.menu-btn{
  position: absolute;
  z-index: 2;
  right: 20px;
  /* left: 20px; */
  top: 20px;
  height: 50px;
  width: 50px;
  text-align: center;
  line-height: 50px;
  border-radius: 50%;
  font-size: 20px;
  color: #fff;
  cursor: pointer;
  /*background: linear-gradient(-135deg, #c850c0, #4158d0);*/
  /* background: linear-gradient(375deg, #1cc7d0, #2ede98); */
 /* background: linear-gradient(-45deg, #e3eefe 0%, #efddfb 100%); */
  background: #000;
  transition: all 0.3s ease-in-out;
}
#active:checked ~ .menu-btn{
  color: #fff;
}
#active:checked ~ .menu-btn i:before{
  content: "\f00d";
}
.wrapper ul{
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  list-style: none;
  text-align: center;
}
.wrapper ul li{
  margin: 15px 0;
}
.wrapper ul li a{
  color: none;
  text-decoration: none;
  font-size: 30px;
  font-weight: 500;
  padding: 5px 30px;
  color: #fff;
  border-radius: 50px;
  background: #000;
  position: relative;
  line-height: 50px;
  transition: all 0.3s ease;
}
.wrapper ul li a:after{
  position: absolute;
  content: "";
  background: #fff;
   background: linear-gradient(#14ffe9, #ffeb3b, #ff00e0);
  /*background: linear-gradient(375deg, #1cc7d0, #2ede98);*/
  width: 104%;
  height: 110%;
  left: -2%;
  top: -5%; /* if the font is 'Oswald'*/
  border-radius: 50px;
  transform: scaleY(0);
  z-index: -1;
  animation: rotate 1.5s linear infinite;
  transition: transform 0.3s ease;
}
.wrapper ul li a:hover:after{
  transform: scaleY(1);
}
.wrapper ul li a:hover{
  color: #fff;
}
input[type="checkbox"]{
  display: none;
}
.content{
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: -1;
  text-align: center;
  width: 100%;
  color: #202020;
}
.content .title{
  font-size: 40px;
  font-weight: 700;
}
.content p{
  font-size: 35px;
  font-weight: 600;
}

@keyframes rotate {
  0%{
    filter: hue-rotate(0deg);
  }
  100%{
    filter: hue-rotate(360deg);
  }
}

// inspired by https://www.codingnepalweb.com/2020/08/fullscreen-overlay-navigation-menu-bar.html

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

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