根据窗口使元素宽度为百分比

Question

我正在尝试制作max-width 400px并拥有实际的width 70%（百分比值）。问题是，父元素的6px值为width。因此，子元素为70%的{​​{1}}，我希望它为页面的6px。

如何让孩子70%占整页width的百分比？

在下面的示例中，我正在尝试制作width（第42行），.timeline ul li div和max-width: 400px width。

JSFiddle

70%

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font: normal 16px/1.5"Helvetica Neue", sans-serif;
  background: #456990;
  color: #fff;
  overflow-x: hidden;
  padding-bottom: 50px;
}
/* TIMELINE
–––––––––––––––––––––––––––––––––––––––––––––––––– */

.timeline ul li {
  list-style-type: none;
  position: relative;
  width: 6px;
  margin: 0 auto;
  padding-top: 50px;
  background: #fff;
}
.timeline ul li::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: inherit;
}
.timeline ul li div {
  position: relative;
  bottom: 0;
  /*max-width: 400px;
  width: 70%;*/
  width: 400px;
  padding: 15px;
  background: #F45B69;
}
.timeline ul li div::before {
  content: '';
  position: absolute;
  bottom: 7px;
  width: 0;
  height: 0;
  border-style: solid;
}
.timeline ul li:nth-child(odd) div {
  left: 45px;
}
.timeline ul li:nth-child(odd) div::before {
  left: -15px;
  border-width: 8px 16px 8px 0;
  border-color: transparent #F45B69 transparent transparent;
}
.timeline ul li:nth-child(even) div {
  left: -439px;
}
.timeline ul li:nth-child(even) div::before {
  right: -15px;
  border-width: 8px 0 8px 16px;
  border-color: transparent transparent transparent #F45B69;
}

Answer 1

使用viewport units：70vw

这意味着70％的视口宽度。

div {

}

.small {
  height: 240px;
  width: 40px;
  background: blue;
 }

.big {
  background: yellow;
  width: 70vw;
  height: 200px;
}

<div class="small">
  <div class="big"></div>
</div>

Answer 2

使用大众单位可行。

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font: normal 16px/1.5"Helvetica Neue", sans-serif;
  background: #456990;
  color: #fff;
  overflow-x: hidden;
  padding-bottom: 50px;
}
/* TIMELINE
–––––––––––––––––––––––––––––––––––––––––––––––––– */

.timeline ul li {
  list-style-type: none;
  position: relative;
  width: 6px;
  margin: 0 auto;
  padding-top: 50px;
  background: #fff;
}
.timeline ul li::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: inherit;
}
.timeline ul li div {
  position: relative;
  bottom: 0;
  
  width: 70vw;

  padding: 15px;
  background: #F45B69;
}
.timeline ul li div::before {
  content: '';
  position: absolute;
  bottom: 7px;
  width: 0;
  height: 0;
  border-style: solid;
}
.timeline ul li:nth-child(odd) div {
  left: 45px;
}
.timeline ul li:nth-child(odd) div::before {
  left: -15px;
  border-width: 8px 16px 8px 0;
  border-color: transparent #F45B69 transparent transparent;
}
.timeline ul li:nth-child(even) div {
  left: -439px;
}
.timeline ul li:nth-child(even) div::before {
  right: -15px;
  border-width: 8px 0 8px 16px;
  border-color: transparent transparent transparent #F45B69;
}

<section class="timeline">
  <ul>
    <li>
      <div>
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      </div>
    </li>
    <li>
      <div>
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      </div>
    </li>
    <li>
      <div>
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      </div>
    </li>
    <li>
      <div>
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      </div>
    </li>
    <li>
      <div>
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      </div>
    </li>
    <li>
      <div>
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      </div>
    </li>
  </ul>
</section>