For what reasons would an absolute div position itself in relation to a static parent?

Question

I have an absolutely positioned Bootstrap 3 dropdown mega menu that is offsetting it's position from a static parent div. I want it to position itself to a relative parent that's further up the DOM.

I've tried using !important rules to set every parent (but the correct one) to position: static - but this won't work.

This doesn't have the correct visuals, but this CodePen demonstrates the issue:

https://codepen.io/anon/pen/mNEyVR

.site-header {
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  display: block;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  height: 150.15px;
  line-height: 22.85px;
  position: relative;
  -moz-osx-font-smoothing: grayscale;
}

.site-header__main {
  border-bottom-color: rgb(236, 236, 236);
  border-bottom-style: solid;
  border-bottom-width: 1px;
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  height: 85px;
  line-height: 22.85px;
  margin-bottom: 0px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  padding-bottom: 0px;
  padding-left: 0px;
  padding-right: 0px;
  padding-top: 0px;
  position: relative;
  -moz-osx-font-smoothing: grayscale;
}

.site-header__main-inner {
  background-attachment: scroll;
  background-clip: border-box;
  background-color: rgb(255, 255, 255);
  background-image: none;
  background-origin: padding-box;
  background-position: 0% 0%;
  background-position-x: 0%;
  background-position-y: 0%;
  background-repeat: repeat;
  background-size: auto;
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  height: 68px;
  line-height: 22.85px;
  margin-bottom: 16px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 16px;
  padding-bottom: 0px;
  padding-left: 40px;
  padding-right: 40px;
  padding-top: 0px;
  position: relative;
  z-index: 999;
  -moz-box-direction: normal;
  -moz-box-orient: horizontal;
  -moz-osx-font-smoothing: grayscale;
}

.site-nav {
  background-attachment: scroll;
  background-clip: border-box;
  background-color: rgba(0, 0, 0, 0);
  background-image: none;
  background-origin: padding-box;
  background-position: 0% 0%;
  background-position-x: 0%;
  background-position-y: 0%;
  background-repeat: repeat;
  background-size: auto;
  border-top-color: rgb(51, 51, 51);
  border-top-style: none;
  border-top-width: 0px;
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  flex-basis: 0px;
  flex-grow: 1;
  flex-shrink: 0;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  height: 68px;
  left: 0px;
  line-height: 22.85px;
  margin-bottom: 0px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  overflow: visible;
  overflow-x: visible;
  overflow-y: visible;
  padding-bottom: 0px;
  padding-left: 0px;
  padding-right: 0px;
  padding-top: 0px;
  position: static;
  top: 0px;
  transform: matrix(1, 0, 0, 1, 0, 0);
  transition-delay: 0s, 0s, 0s;
  transition-duration: 0.36s, 0.36s, 0.36s;
  transition-property: transform, visibility, transform;
  transition-timing-function: ease, ease, ease;
  visibility: visible;
  width: 1015px;
  z-index: auto;
  -moz-box-flex: 1;
  -moz-osx-font-smoothing: grayscale;
}

nav {
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  display: block;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 22.85px;
  margin-bottom: 0px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  visibility: visible;
  -moz-osx-font-smoothing: grayscale;
}

ul {
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  display: flex;
  float: left;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  justify-content: flex-end;
  line-height: 22.85px;
  list-style-image: none;
  list-style-position: outside;
  list-style-type: none;
  margin-bottom: 0px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  padding-bottom: 0px;
  padding-left: 0px;
  padding-right: 0px;
  padding-top: 0px;
  visibility: visible;
  width: 1015px;
  -moz-box-pack: end;
  -moz-osx-font-smoothing: grayscale;
}

li.open {
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  display: block;
  float: none;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 22.85px;
  list-style-image: none;
  list-style-position: outside;
  list-style-type: none;
  margin-bottom: 0px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  padding-bottom: 0px;
  padding-left: 0px;
  padding-right: 0px;
  padding-top: 0px;
  position: static;
  visibility: visible;
  -moz-osx-font-smoothing: grayscale;
}

.dropdown-menu {
  background-attachment: scroll;
  background-clip: border-box;
  background-color: rgb(236, 236, 236);
  background-image: none;
  background-origin: padding-box;
  background-position: 0% 0%;
  background-position-x: 0%;
  background-position-y: 0%;
  background-repeat: repeat;
  background-size: auto;
  border-bottom-color: rgb(214, 214, 214);
  border-bottom-left-radius: 4px;
  border-bottom-right-radius: 4px;
  border-bottom-style: solid;
  border-bottom-width: 1px;
  border-image-outset: 0;
  border-image-repeat: stretch;
  border-image-slice: 100%;
  border-image-source: none;
  border-image-width: 1;
  border-left-color: rgb(51, 51, 51);
  border-left-style: none;
  border-left-width: 0px;
  border-right-color: rgb(51, 51, 51);
  border-right-style: none;
  border-right-width: 0px;
  border-top-color: rgb(51, 51, 51);
  border-top-left-radius: 0px;
  border-top-right-radius: 0px;
  border-top-style: none;
  border-top-width: 0px;
  box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  display: none;
  float: none;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  left: 0px;
  line-height: 22.85px;
  list-style-image: none;
  list-style-position: outside;
  list-style-type: none;
  margin-bottom: 0px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  min-width: 160px;
  padding-bottom: 32px;
  padding-left: 0px;
  padding-right: 0px;
  padding-top: 16px;
  position: absolute;
  text-align: left;
  top: 100%;
  visibility: visible;
  width: 100%;
  z-index: 1000;
  -moz-osx-font-smoothing: grayscale;
}

li.open .dropdown-menu {
  background-attachment: scroll;
  background-clip: border-box;
  background-color: rgb(236, 236, 236);
  background-image: none;
  background-origin: padding-box;
  background-position: 0% 0%;
  background-position-x: 0%;
  background-position-y: 0%;
  background-repeat: repeat;
  background-size: auto;
  border-bottom-color: rgb(214, 214, 214);
  border-bottom-left-radius: 4px;
  border-bottom-right-radius: 4px;
  border-bottom-style: solid;
  border-bottom-width: 1px;
  border-image-outset: 0;
  border-image-repeat: stretch;
  border-image-slice: 100%;
  border-image-source: none;
  border-image-width: 1;
  border-left-color: rgb(51, 51, 51);
  border-left-style: none;
  border-left-width: 0px;
  border-right-color: rgb(51, 51, 51);
  border-right-style: none;
  border-right-width: 0px;
  border-top-color: rgb(51, 51, 51);
  border-top-left-radius: 0px;
  border-top-right-radius: 0px;
  border-top-style: none;
  border-top-width: 0px;
  box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;
  box-sizing: border-box;
  color: rgb(51, 51, 51);
  display: block;
  float: none;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  left: 0px;
  line-height: 22.85px;
  list-style-image: none;
  list-style-position: outside;
  list-style-type: none;
  margin-bottom: 0px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  min-width: 160px;
  padding-bottom: 32px;
  padding-left: 0px;
  padding-right: 0px;
  padding-top: 16px;
  position: absolute;
  text-align: left;
  top: 68px;
  visibility: visible;
  width: 1015px;
  z-index: 1000;
  -moz-osx-font-smoothing: grayscale;
}

<header class="site-header">
  <div class="site-header__main">
    <div class="site-header__main-inner">
      <div class="site-nav">
        <nav>
          <ul>
            <li class="open">
              <a href="#">Link 1</a>
              <div class="dropdown-menu">
                <p>content 1</p>
              </div>
            </li>
            <li>
              <a href="#">Link 2</a>
              <div class="dropdown-menu">
                <p>content 2</p>
              </div>
            </li>
            <li>
              <a href="#">Link 3</a>
              <div class="dropdown-menu">
                <p>content 3</p>
              </div>
            </li>
          </ul>
        </nav>
      </div>
    </div>
  </div>
</header>

If you Inspect the first .dropdown-menu in Firefox, you'll see in the Layout tab that the menu is positioning itself in relation to a static parent.

It should be positioning in relation to a further-up parent that actually has its position set to relative.

Thank you, Temani! I was working on cleaning up the CSS and I noticed halfway through that the problem was fixed. I've answered my own question below. — user1566957, Jul 24 '19 at 20:28

score 0 · Answer 1 · answered Jul 24 '19 at 20:31

I tried reducing my code the make it easier to parse and I solved my own problem.

The div .site-nav was incorrectly acting a the relative parent to my absolute div.

For some reason, this was caused by this CSS: transform: matrix(1, 0, 0, 1, 0, 0);

I've never used the matrix code before so I don't know what this does. It wasn't even in my code. My code was transform: translateY(0) and apparently my gulp file was adding the goofy matrix content. I changed the transform to transform: none and the problem was fixed!

I added a duplicate question to explain this – Temani Afif Jul 24 '19 at 20:37 — Temani Afif, Jul 24 '19 at 20:37

For what reasons would an absolute div position itself in relation to a static parent?

1 Answers1