How to make CSS Dropdown menu slidedown

Question

I created a CSS menu with dropdown and I hide the sub menu and display it when you hover over the menu item and I was wondering if it is possible with CSS with some type of CSS transition to make it instead slide down. You cake take a look at a mock up of the menu here.

#main-nav {
  position: relative;
}

#main-nav>ul>li {
  width: 12.5%;
  float: left;
  text-align: center;
  line-height: .9em;
  font-weight: bold;
  background: #ccc;
}

#main-nav>ul>li>a {
  display: block;
  color: #333;
  line-height: 12px;
  font-size: 14px;
  padding: 22px 0;
  text-decoration: none;
}

.nav-dropdown {
  margin: -5px auto;
  position: absolute;
  left: -999em;
  /* Hides the drop down */
  text-align: left;
  padding: 0;
  border-top: 0;
  width: 500px;
  background: #333;
  color: #f2f2f2;
  border-bottom: 10px solid #25272a;
  -webkit-border-bottom-right-radius: 5px;
  -webkit-border-bottom-left-radius: 5px;
  -moz-border-radius-bottomright: 5px;
  -moz-border-radius-bottomleft: 5px;
  border-bottom-right-radius: 5px;
  border-bottom-left-radius: 5px;
}

#main-nav li:hover .nav-dropdown {
  left: 0;
  top: auto;
  z-index: 11;
}

<div id="main-nav">
  <ul>
    <li><a href="#">Item 1</a></li>
    <li><a href="#">Item 2</a></li>
    <li><a href="#">Item 3</a>
      <!-- Start Blog Drop Down-->
      <div class="nav-dropdown">
        <p>have this item slide down from CSS</p>
      </div>
      <!-- /.nav-dropdown -->
    </li>
  </ul>
</div>

score 2 · Answer 1 · edited Dec 21 '18 at 07:16

Yes you can, but you need to use the max-height property as described here or you can just use a fixed height as described in the previous answer.

CSS

.nav-dropdown {
    margin: 0 auto;  
    height: 0; /* Hides the drop down */ 
    overflow: hidden;
    text-align:left;  
    padding: 0;  
    border-top: 0;
    width: 500px;
    background:#333;
    color: #f2f2f2;
    -webkit-border-bottom-right-radius: 5px;
    -webkit-border-bottom-left-radius: 5px;
    -moz-border-radius-bottomright: 5px;
    -moz-border-radius-bottomleft: 5px;
    border-bottom-right-radius: 5px;
    border-bottom-left-radius: 5px;
    border-bottom: 0;
    max-height:0px;
}

#main-nav li:hover .nav-dropdown {
    height:auto;
    z-index: 11; 
    max-height:200px;
    transition-property: all;
    transition-duration: 1s;
    border-bottom: 10px solid #25272a;
}

http://jsfiddle.net/L8WVP/7/

This might also be of your interest.

Thanks Patrick, if you have the time can you take a look at http://hearthable.com and you'll see it in actual use but just the background slides in not the actual content. — Greenhoe, May 17 '14 at 22:56

score 0 · Answer 2 · answered May 17 '14 at 22:20

0

That should help you. Just give the div tag which should slide in the hight 0 at first and make the css transition.

-webkit-transition: height 0.5s ease-in;
-moz-transition: height 0.5s ease-in;
-o-transition: height 0.5s ease-in;
-ms-transition: height 0.5s ease-in;
transition: height 0.5s ease-in;

Then you add at the hover section the hight of the div.

#main-nav li:hover .nav-dropdown {
    left: 0;
    top: auto;
    z-index: 11; 
    height:200px;
}

And you are done. Hope I helped you.

http://jsfiddle.net/L8WVP/6/

answered May 17 '14 at 22:20

user3631948

85
1
7

thanks, but if you take a look it in effect with a mega drop down that is dynamic based off wordpress posts I'm having a little issue as the content shows up while it slides in. you can take a look at http://hearthable.com and see the issue i"m talking about. – Greenhoe May 17 '14 at 22:56
Yea, that is the issue I'm having where the background is sliding down but the content isn't so it just looks a bit odd – Greenhoe May 17 '14 at 23:53

score 0 · Answer 3 · answered Dec 21 '18 at 05:26

<ul class="navigation">
    <li><a href="#">Home</a></li>
    <li class="menu">
    <a href="#">Services</a>
    <ul class="submenu">
      <li><a href="#">Link 1</a></li>
      <li><a href="#">Link 2</a></li>
      <li><a href="#">Link 3</a></li>
      <li><a href="#">Link 4</a></li>
    </ul>
  </li>
  <li><a href="#">About</a></li>
  <li><a href="#">Contact</a></li>
</ul>

    ul {
  padding: 0;
  margin: 0;
  list-style: none;
}
ul li a {
  text-decoration: none;
  color: #e74c3c;
  font-family: Tahoma, Arial;
}
.navigation {
  background-color: a#e74c3c;
  width: 75%;
  margin: 20px auto;
  min-height: 50px;
}
.navigation > li {
  float: left;
  padding: 0 20px;
}
.navigation > li > a {
  line-height: 50px;
  color: #FFF;
}
.navigation .menu {
  position: relative
}
.navigation .menu .submenu {
  position: absolute;
  width: 200px;
  -webkit-box-shadow: 0px 1px 1px #CCC;
  box-shadow: 0px 1px 1px #CCC;
  display: none;
  -webkit-transition: all .5s ease-in-out;
  -moz-transition: all .5s ease-in-out;
  transition: all .5s ease-in-out;
}
.navigation .menu:hover .submenu {
  display: block
}
.navigation .menu .submenu:before {
  content: "";
  position: absolute;
  display: block;
  border-width: 0 6px 6px 6px;
  border-style: solid;
  border-color: #FFF transparent;
  top: -6px;
  left: 5px
}
.navigation .menu .submenu li {
  padding: 5px 10px;
  -webkit-transition: all .5s ease-in-out;
  -moz-transition: all .5s ease-in-out;
  transition: all .5s ease-in-out;
}
.navigation .menu .submenu li:hover {
  background-color: #e74c3c;
}
.navigation .menu .submenu li:hover a {
  color: #FFF;
  padding: 0 11px;
}

How to make CSS Dropdown menu slidedown

3 Answers3