Denne virker IKKE på mobilen!

CSS-tricks Solved with CSS! Dropdown Menus

https://css-tricks.com/solved-with-css-dropdown-menus/

Denne krever i tillegg en CLEARFIX-løsning, som jeg har satt lokat på en DIV.

<div style='content: ""; clear: both; display: table;'></div>

Una Kravets on Dec 13, 2020

a {
  text-decoration: none;
}

nav {
  font-family: monospace;
}

ul {
  background: darkorange;
  list-style: none;
  margin: 0;
  padding-left: 0;
}

li {
  color: #fff;
  background: darkorange;
  display: block;
  float: left;
  padding: 1rem;
  position: relative;
  text-decoration: none;
  transition-duration: 0.5s;
}
  
li a {
  color: #fff;
}

li:hover,
li:focus-within {
  background: red;
  cursor: pointer;
}

li:focus-within a {
  outline: none;
}

ul li ul {
  background: orange;
  visibility: hidden;
  opacity: 0;
  min-width: 5rem;
  position: absolute;
  transition: all 0.5s ease;
  margin-top: 1rem;
  left: 0;
  display: none;
}

ul li:hover > ul,
ul li:focus-within > ul,
ul li ul:hover,
ul li ul:focus {
  visibility: visible;
  opacity: 1;
  display: block
}

ul li ul li {
  clear: both;
  width: 100%;
}
<nav role="navigation">
  <ul>
    <li><a href="#">One</a></li>
    <li><a href="#">Two</a>
      <ul class="dropdown">
        <li><a href="#">Sub-1</a></li>
        <li><a href="#">Sub-2</a></li>
        <li><a href="#">Sub-3</a></li>
      </ul>
    </li>
    <li><a href="#">Three</a></li>
  </ul>
</nav>