Nested Dropdown Menu In Pure CSS

Preview:

Description:

A CSS-only multi-level dropdown menu, animated with CSS3 transitions, transforms, and animations.

How to use it:

Create the multi-level dropdown menu from a nested nav list as follow:

<nav>
  <input id="css-menu" type="checkbox">
  <label class="down" for="css-menu">
    <h2>Menu</h2>
  </label>
  <ul>
    <li>
      <input id="link-gallery" type="checkbox">
      <label class="right" for="link-gallery">Category</label>
      <ul>
        <li>
          <a>JavaScript</a>
        </li>
        <li>
          <a>HTML5</a>
        </li>
        <li>
          <a>CSS/CSS3</a>
        </li>
        <li>
          <a>Ruby</a>
        </li>
        <li>
          <a>Python</a>
        </li>
      </ul>
    </li>
    <li>
      <a>Blog</a>
    </li>
    <li>
      <a>About</a>
    </li>
    <li>
      <a>Contact</a>
    </li>
  </ul>
</nav>

The basic CSS styles for the nav menu.

nav {
  position: relative;
  opacity: 0;
  -webkit-animation: bounceInUp 1000ms linear 500ms forwards;
  animation: bounceInUp 1000ms linear 500ms forwards;
}
nav label, nav a {
  -webkit-transition: all 150ms ease-out;
  transition: all 150ms ease-out;
  cursor: pointer;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -ms-flex-line-pack: center;
  align-content: center;
  height: 48px;
  width: 216px;
  padding: 0 12px;
  background: white;
  border: 2px solid #A6ADA7;
  border-radius: 2px;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -1px;
}
nav a:hover, nav a:focus { border-color: #d0ddd1; }
nav a:active { border-color: #F5C8BF; }
nav label { position: relative; }
nav label:before, nav label:after {
  -webkit-transition: all 150ms ease-out;
  transition: all 150ms ease-out;
  content: "";
  display: block;
  position: absolute;
  width: 2px;
  height: 12px;
  background: #A6ADA7;
  border-radius: 2px;
}
nav label:before {
  -webkit-transform: rotate(-45deg);
  transform: rotate(-45deg);
}
nav label:after {
  -webkit-transform: rotate(45deg);
  transform: rotate(45deg);
}
nav label.down:before, nav label.down:after {
  -webkit-transform-origin: center 11px;
  transform-origin: center 11px;
  top: 50%;
  margin-top: -6px;
  right: 20px;
}
nav label.right:before, nav label.right:after {
  -webkit-transform-origin: left center;
  transform-origin: left center;
  top: 50%;
  right: 20px;
}
nav label.right:before { margin-top: -9px; }
nav label.right:after { margin-top: -3px; }
nav > label {
  -webkit-transform: translateZ(1px);
  transform: translateZ(1px);
  z-index: 1;
}
nav ul {
  will-change: visibility;
  -webkit-transition: visibility 0ms ease-out 600ms;
  transition: visibility 0ms ease-out 600ms;
  visibility: hidden;
  z-index: 1;
}
nav ul li {
  will-change: transform, opacity;
  padding: 4px 0;
  opacity: 0;
}
nav > ul {
  position: relative;
  padding-top: 4px;
}
nav > ul > li {
  -webkit-transform: translateY(-100%);
  transform: translateY(-100%);
}
nav > ul > li > label {
  -webkit-transform: translateZ(0.5px);
  transform: translateZ(0.5px);
}
nav > ul ul {
  position: absolute;
  top: 0;
  right: -224px;
}
nav > ul ul > li {
  -webkit-transform: translateX(-100%);
  transform: translateX(-100%);
}
nav input {
  cursor: pointer;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  opacity: 0;
  position: absolute;
  width: 216px;
  height: 48px;
  margin: 0;
}
nav input:hover ~ label, nav input:focus ~ label { border-color: #d0ddd1; }
nav input:active ~ label { border-color: #F5C8BF; }
nav input:checked ~ label { border-color: #AEBFAF; }
nav input:checked ~ label.down:before, nav input:checked ~ label.down:after { margin-top: -16px; }
nav input:checked ~ label.down:before {
  -webkit-transform: rotate(-135deg);
  transform: rotate(-135deg);
}
nav input:checked ~ label.down:after {
  -webkit-transform: rotate(135deg);
  transform: rotate(135deg);
}
nav input:checked ~ label.right:before {
  -webkit-transform: rotate(45deg);
  transform: rotate(45deg);
  margin-top: -11px;
}
nav input:checked ~ label.right:after {
  -webkit-transform: rotate(-45deg);
  transform: rotate(-45deg);
  margin-top: -2px;
}
nav input:checked ~ ul {
  visibility: visible;
  -webkit-transition: visibility 0ms ease-out 0ms;
  transition: visibility 0ms ease-out 0ms;
}
nav input:checked ~ ul > li {
  opacity: 1;
  -webkit-transform: none;
  transform: none;
}
nav > input {
  z-index: 2;
  top: 0;
  left: 0;
}
nav > input:not(:checked) ~ ul > li input:checked ~ ul li {
  opacity: 0;
  -webkit-transform: translateX(-100%);
  transform: translateX(-100%);
}

Style & activate the sub menu.

nav ul li:nth-child(1) {
  -webkit-transition: opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
  transition: opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms, opacity 100ms ease-out 500ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms, opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
}
nav ul li:nth-child(2) {
  -webkit-transition: opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
  transition: opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms, opacity 100ms ease-out 400ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms, opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
}
nav ul li:nth-child(3) {
  -webkit-transition: opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
  transition: opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms, opacity 100ms ease-out 300ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms, opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
}
nav ul li:nth-child(4) {
  -webkit-transition: opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
  transition: opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms, opacity 100ms ease-out 200ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms, opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
}
nav ul li:nth-child(5) {
  -webkit-transition: opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
  transition: opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms, opacity 100ms ease-out 100ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms, opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
}
nav input:checked ~ ul > li:nth-child(1) {
  -webkit-transition: opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
  transition: opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms, opacity 100ms ease-out 100ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms, opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
}
nav input:checked ~ ul > li:nth-child(2) {
  -webkit-transition: opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
  transition: opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms, opacity 100ms ease-out 200ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms, opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
}
nav input:checked ~ ul > li:nth-child(3) {
  -webkit-transition: opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
  transition: opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms, opacity 100ms ease-out 300ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms, opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
}
nav input:checked ~ ul > li:nth-child(4) {
  -webkit-transition: opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
  transition: opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms, opacity 100ms ease-out 400ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms, opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
}
nav input:checked ~ ul > li:nth-child(5) {
  -webkit-transition: opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
  transition: opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms, opacity 100ms ease-out 500ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms, opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
}
nav > input:not(:checked) ~ ul > li input:checked ~ ul li:nth-child(1) {
  -webkit-transition: opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
  transition: opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms, opacity 100ms ease-out 500ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms, opacity 100ms ease-out 500ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 500ms;
}
nav > input:not(:checked) ~ ul > li input:checked ~ ul li:nth-child(2) {
  -webkit-transition: opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
  transition: opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms, opacity 100ms ease-out 400ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms, opacity 100ms ease-out 400ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 400ms;
}
nav > input:not(:checked) ~ ul > li input:checked ~ ul li:nth-child(3) {
  -webkit-transition: opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
  transition: opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms, opacity 100ms ease-out 300ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms, opacity 100ms ease-out 300ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 300ms;
}
nav > input:not(:checked) ~ ul > li input:checked ~ ul li:nth-child(4) {
  -webkit-transition: opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
  transition: opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms, opacity 100ms ease-out 200ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms, opacity 100ms ease-out 200ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 200ms;
}
nav > input:not(:checked) ~ ul > li input:checked ~ ul li:nth-child(5) {
  -webkit-transition: opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
  transition: opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms, opacity 100ms ease-out 100ms;
  transition: transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms, opacity 100ms ease-out 100ms, -webkit-transform 150ms cubic-bezier(0, 0.5, 0.5, 1.1) 100ms;
}

The bounce animations.

@-webkit-keyframes 
bounceInUp {  0% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 200, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 200, 0, 1);
 opacity: 0;
}
 5.51% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 95.356, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 95.356, 0, 1);
}
 11.01% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 23.691, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 23.691, 0, 1);
}
 16.52% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -9.467, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -9.467, 0, 1);
}
 21.92% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -16.994, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -16.994, 0, 1);
}
 36.24% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -3.682, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -3.682, 0, 1);
 opacity: 1;
}
 50.55% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1.004, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1.004, 0, 1);
}
 79.08% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -0.059, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -0.059, 0, 1);
}
 100% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
 opacity: 1;
}
}
@keyframes 
bounceInUp {  0% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 200, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 200, 0, 1);
 opacity: 0;
}
 5.51% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 95.356, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 95.356, 0, 1);
}
 11.01% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 23.691, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 23.691, 0, 1);
}
 16.52% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -9.467, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -9.467, 0, 1);
}
 21.92% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -16.994, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -16.994, 0, 1);
}
 36.24% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -3.682, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -3.682, 0, 1);
 opacity: 1;
}
 50.55% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1.004, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1.004, 0, 1);
}
 79.08% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -0.059, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, -0.059, 0, 1);
}
 100% {
 -webkit-transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
 transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
 opacity: 1;
}
}