背景颜色不包括整个<a>-element when hovered

Question

I am currently coding a navigation bar where when the links are hovered, the background-color of the -element changes. Currently, the background-color in the navigation bar's dropdown menu does not cover the entire "box".

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}

ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  background-color: black;
}

ul li {
  display: inline-block;
  position: relative;
  background-color: black;
}

ul li a {
  display: block;
  color: white;
  text-decoration: none;
  text-align: center;
  margin: -left:0;
  padding: 15px 25px;
  -webkit-transition-duration: 0.4s;
  transition-duration: 0.4s;
}

ul li a:hover {
  background-color: #333;
}

ul li ul#dropdowncontent {
  display: inline-block;
  position: absolute;
  text-align: center;
  min-width: 100%;
  font-size: 70%;
  z-index: 999;
  width: 90px;
}

<ul>
  <li><a href="#">Produkter</a>
    <ul id="dropdowncontent">
      <li><a href="#">Moderkort</a></li>
      <li><a href="#">Processorer</a></li>
      <li><a href="#">Hårddiskar</a></li>
      <li><a href="#">Grafikkort</a></li>
    </ul>
  </li>
  <li><a href="#">Butiker</a></li>
  <li><a href="#">Kontakt</a></li>
  <li><a href="#">Vanliga frågor</a></li>
</ul>

You can also take a look at the code in this Jsfiddle: https://jsfiddle.net/fdvcmnx6/

Answer 1

将下拉列表项设置为display: block。

#dropdowncontent li {
    display: block;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}

ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  background-color: black;
}

ul li {
  display: inline-block;
  position: relative;
  background-color: black;
}

ul li a {
  display: block;
  color: white;
  text-decoration: none;
  text-align: center;
  margin: -left:0;
  padding: 15px 25px;
  -webkit-transition-duration: 0.4s;
  transition-duration: 0.4s;
}

ul li a:hover {
  background-color: #333;
}

ul li ul#dropdowncontent {
  display: inline-block;
  position: absolute;
  text-align: center;
  min-width: 100%;
  font-size: 70%;
  z-index: 999;
  width: 90px;
}

/* Additional */

#dropdowncontent li {
    display: block;
}

<ul>
  <li><a href="#">Produkter</a>
    <ul id="dropdowncontent">
      <li><a href="#">Moderkort</a></li>
      <li><a href="#">Processorer</a></li>
      <li><a href="#">Hårddiskar</a></li>
      <li><a href="#">Grafikkort</a></li>
    </ul>
  </li>
  <li><a href="#">Butiker</a></li>
  <li><a href="#">Kontakt</a></li>
  <li><a href="#">Vanliga frågor</a></li>
</ul>

Answer 2

设置下拉列表width:100%

#dropdowncontent li {
    display: block;
}