Overlay Navbar Pop in

// HTML
<div class="menu-wrap">
      <input type="checkbox" class="toggler" />
      <div class="hamburger"><div></div></div>
      <div class="menu">
        <div>
          <div>
            <ul>
              <li><a href="#">Home</a></li>
              <li><a href="#">About</a></li>
              <li><a href="#">Services</a></li>
              <li><a href="#">Contact</a></li>
            </ul>
          </div>
        </div>
      </div>
    </div>

// CSS
.menu-wrap .menu {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  visibility: hidden;
}

.menu-wrap .menu > div {
  background-color: steelblue;
  flex: none;
  width: 200vw;
  height: 200vw;
  display: flex;
  justify-content: center;
  align-items: center;
  border-radius: 50%;
  transform: scale(0);
  transition: all 1s ease;
}

.menu-wrap .menu > div > div {
  max-width: 90vw;
  max-height: 100vh;
  opacity: 0;
  transition: opacity 0.4s ease 0.4s;
  text-align: center;
}

.menu-wrap .menu li {
  list-style: none;
  padding: 1rem 0;
  font-size: 1.5rem;
}

.menu-wrap .menu li a {
  text-decoration: none;
  color: white;
  transition: color 0.4s ease;
}

.menu-wrap .toggler:checked ~ .menu {
  visibility: visible;
}

.menu-wrap .toggler:checked ~ .menu > div {
  transform: scale(1);
}

.menu-wrap .toggler:checked ~ .menu > div > div {
  opacity: 1;
}