How can I create a box with an angle one side and rounded corners via CSS?

Question

I currently find myself needing to make something like this.

My first thought was to use clip-path, but the rounded corners would be hard to pull off, and it would be hard to maintain the 22.5 degrees when the button changes width because of its contents.

So I ended up making each button two divs, with one div being skewed by 22.5 degrees and being overlapped by the regular rectangular div. Then I added border radius to both.

body {
  line-height: 0;
  font-size: 16px;
  background-color: black;
}

.cta-button-group {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.button-angular-wrapper-left {
  display: flex;
  isolation: isolate;
  position: relative;
  height: 40px;
  width: fit-content;
}

.button-angular-wrapper-left .button-angular-main {
  border-radius: 7px 0 0 7px;
  height: 100%;
  display: inline-grid;
  place-items: center;
  padding-inline: 8px 16px;
  margin-right: 13px;
  transition: background-color 50ms;
}

.button-angular-wrapper-left .button-angular-slant {
  border-radius: 0 7px 7px 0;
  height: 100%;
  width: 24px;
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  z-index: -1;
  transition: background-color 50ms;
}

.button-angular-wrapper-left .button-angular-slant.back-slash {
  transform: skewX(22.5deg);
}

.button-angular-wrapper-left .button-angular-slant.forward-slash {
  transform: skewX(-22.5deg);
}

.button-angular-wrapper-left.button-angular-color-solid-white .button-angular-main,
.button-angular-wrapper-left.button-angular-color-solid-white .button-angular-slant {
  background: white;
  border: 3px solid white;
  color: blue;
}

.button-angular-wrapper-left.button-angular-color-solid-white .button-angular-main {
  border-right: none;
}

.button-angular-wrapper-left.button-angular-color-solid-white .button-angular-slant {
  border-left: none;
}

.button-angular-wrapper-right {
  display: flex;
  isolation: isolate;
  position: relative;
  height: 40px;
  width: fit-content;
}

.button-angular-wrapper-right .button-angular-main {
  border-radius: 0 7px 7px 0;
  height: 100%;
  display: inline-grid;
  place-items: center;
  padding-inline: 8px 16px;
  margin-left: 13px;
}

.button-angular-wrapper-right .button-angular-slant {
  border-radius: 7px 0 0 7px;
  height: 100%;
  width: 24px;
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  z-index: -1;
}

.button-angular-wrapper-right .button-angular-slant.back-slash {
  transform: skewX(22.5deg);
}

.button-angular-wrapper-right .button-angular-slant.forward-slash {
  transform: skewX(-22.5deg);
}

.button-angular-wrapper-right.button-angular-color-outline-white .button-angular-main,
.button-angular-wrapper-right.button-angular-color-outline-white .button-angular-slant {
  border: 3px solid white;
}

.button-angular-wrapper-right.button-angular-color-outline-white .button-angular-main {
  border-left: none;
}

.button-angular-wrapper-right.button-angular-color-outline-white .button-angular-main .icon-call {
  color: white;
}

.button-angular-wrapper-right.button-angular-color-outline-white .button-angular-main .cta-text {
  color: white;
}

.button-angular-wrapper-right.button-angular-color-outline-white .button-angular-slant {
  border-right: none;
}

<div class="cta-button-group">
  <div class="button-angular-wrapper-left button-angular-color-solid-white" href="">
    <div class="button-angular-main">
      <span class="cta-text">
        Learn More Today
      </span>
    </div>
    <div class="button-angular-slant back-slash">
    </div>
  </div>
  <div class="button-angular-wrapper-right button-angular-color-outline-white" href="">
    <div class="button-angular-main">
      <span class="cta-text tel-link-no">
        1800-1-5555
      </span>
    </div>
    <div class="button-angular-slant back-slash">
    </div>
  </div>
</div>

CodePen: https://codepen.io/katylar/pen/yLRjKaO

It works, but it's not perfect. I notice significant artifacts and weird corners/edges on some browsers at some resolutions.

Is there a good solution? That doesn't involved masks (which I always have a hard time with, sizing-wise)?

Answer 1

I've tried this approach with pseudo elements. The left side of this shape is a ::before element and for the hover effect I turned specific sides on the button and pseudo element invisible and also changed the border raduis of specific corners.

.button {
  color: white;
  background-color: black;
  text-align: center;
  text-transform: uppercase;
  padding: 5px 10px;
  margin: 11px;
  display: inline-block;
  border-radius: 4px;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
  border: 2px solid black;
  -ms-transform: skewX(-20deg);
  -webkit-transform: skewX(-20deg);
  transform: skewX(-20deg);
}

.button-left::before {
  content: " ";
  display: block;
  position: absolute;
  top: -2px;
  left: -12px;
  z-index: -10;
  background-color: black;
  width: 20px;
  height: 100%;
  -ms-transform: skewX(20deg);
  -webkit-transform: skewX(20deg);
  transform: skewX(20deg);
  border-radius: 4px;
  border: 2px solid black;
}

.button-left:hover {
  background: rgba(0,0,0,0);
  box-sizing: border-box;
  border: 2px solid black;
  border-left: 2px solid rgba(0,0,0,0);
  color: black;
  border-top-left-radius: 0;
}

.button-left:hover::before {
  border-right: 2px solid rgba(0,0,0,0);
  background: rgba(0,0,0,0);
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}

.button-content {
  -ms-transform: skewX(20deg);
  -webkit-transform: skewX(20deg);
  transform: skewX(20deg);  
  display: inline-block;
}

<div class="button button-left">
  <span class="button-content">Slanted Button</span>
</div>