Partial borders from all corners of a div CSS [duplicate]

Question

Is it possible to have a partial border on all the edges of a div starting from each corner? I want to avoid background-image property & use a CSS Only solution to achieve this.

Partial borders are possible using the pseudo :after property but I cant figure out how to have it on all the edges?

The div should look like a focus widget as shown in the attached image.

Thanks.

Answer 1

Sure, try this:

HTML:

<div></div>

CSS:

div {
    background: white;
    padding: 1.7em;
    position: relative;
    width: 300px;
    height: 300px;
    margin: 3em auto;
    border: solid 2px #d00;
}
div::before, div::after {
    position: absolute;
    background: inherit;
    content: '';
    z-index: 1;
}
div::before {
    width: 100px;
    left: calc(50% - 50px);
    height: calc(100% + 4px);
    top: -2px;
}
div::after {
    height: 100px;
    left: -2px;
    width: calc(100% + 4px);
    top: calc(50% - 50px);
}
div > * {
    position: relative; z-index: 2; /* ensure any child elements sit above pseudos */
}

Fiddle.

Answer 2

You can do this with two extra elements for borders so you don't have to mask backgrounds and you can have transparent background.

.element {
  width: 200px;
  height: 200px;
  margin: 50px;
  position: relative;
  padding: 10px;
}
.top-border,
.bottom-border {
  position: absolute;
  display: flex;
  justify-content: space-between;
  width: 100%;
  height: 30%;
  left: 0;
}
.top-border {
  top: 0;
}
.bottom-border {
  bottom: 0;
}
.top-border:after,
.top-border:before,
.bottom-border:after,
.bottom-border:before {
  content: '';
  width: 30%;
  height: 100%;
}
.top-border:after,
.top-border:before {
  border-top: 1px solid green;
}
.bottom-border:after,
.bottom-border:before {
  border-bottom: 1px solid green;
}
.top-border:before,
.bottom-border:before {
  border-left: 1px solid green;
}
.top-border:after,
.bottom-border:after {
  border-right: 1px solid green;
}

<div class="element">
  <div class="top-border"></div>
  <div class="bottom-border"></div>
  <div class="content">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Reiciendis, libero!</div>
</div>