CSS 将绝对位置 div 限制为父级大小

Question

所以我需要一个覆盖其整个父级的 div。（需要位于事件监听的前面，因此z-index需要高于父级。）

如果父级没有固定大小，我该怎么办？

例如： https: //jsfiddle.net/CypherK/hdgko1L4/

<div class="container">

    <div class="content"><!-- should be however big the container is-->

        <div class = "mask"></div> <!-- should be in front of the entire content -->

    </div>

</div>

.container {

  height: 3em;

  width: 50%; /*could be anything*/

  border: 1px solid green;

}

.content {

  height: 1em;

  width: 100% - 6px; /*intention: as big as container, minus own borders*/

  border: 3px dashed blue;

}

.content .mask {

  position: absolute;

  z-index: 99;

  height: calc(100% + 6px); /*intention: as big as content, including its borders*/

  width: calc(100% + 6px); /*intention: as big as content, including its borders*/

  margin: -3px; /*intention: place on border of parent*/

  border: 2px dotted red;

}

Answer 1

所以我需要一个覆盖其整个父级的 div。（需要位于事件监听的前面，因此z-index需要高于父级。）如果父级没有固定大小，我该怎么办？例如： https: //jsfiddle.net/CypherK/hdgko1L4/<div class="container">&nbsp; &nbsp; <div class="content"><!-- should be however big the container is-->&nbsp; &nbsp; &nbsp; &nbsp; <div class = "mask"></div> <!-- should be in front of the entire content -->&nbsp; &nbsp; </div></div>.container {&nbsp; height: 3em;&nbsp; width: 50%; /*could be anything*/&nbsp; border: 1px solid green;}.content {&nbsp; height: 1em;&nbsp; width: 100% - 6px; /*intention: as big as container, minus own borders*/&nbsp; border: 3px dashed blue;}.content .mask {&nbsp; position: absolute;&nbsp; z-index: 99;&nbsp; height: calc(100% + 6px); /*intention: as big as content, including its borders*/&nbsp; width: calc(100% + 6px); /*intention: as big as content, including its borders*/&nbsp; margin: -3px; /*intention: place on border of parent*/&nbsp; border: 2px dotted red;}