如何让div外的所有内容变暗？

Question

我有一个购物车抽屉，在单击时从右侧打开。当它打开时，我希望它外部的所有内容变暗，以便仅聚焦于该div（购物车抽屉）。您对如何实现此目标有什么建议吗？

- user4490434

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你能否提供任何HTML和CSS的基本示例，展示一下你目前尝试过的内容？ - G-Cyrillus

你的代码片段并没有提供太多帮助，一小段HTML代码可能会更有效，而不是脚本。 - G-Cyrillus

抱歉，我的意思是：例如{% if cart.item_count > 0 %}并不是很有帮助，一个简单的HTML示例就足以展示你的结构以及哪个元素应该是轻量级的... - G-Cyrillus

Answer 1

基本上，一个巨大的阴影可能会做到：（单击任何编号的div以使其周围变暗）

编辑来自您的评论，我建议：.cart-container{box-shadow:0 0 0 2000px rgba(0,0,0,0.5);}下面是演示效果。

div:focus {
  position:relative;/* bring on top;*/
  box-shadow:0 0 0 1600px rgba(0,0,0,0.65);/* dark around it */
}

/* demo purpose*/
body {
  display: flex;
  flex-wrap: wrap;
  counter-reset: divs -1;
  margin:0;
}
div {
  counter-increment: divs;
  height: 120px;
  width: 120px;
  background: turquoise;
}
div:nth-child(odd) {
  background: tomato;
}
div:not(:first-of-type):before {
  content: counter(divs);
  display: block;
  font-size: 2em;
  margin: 1em;
  color: white;
}

<div>tabindex for demo catches click, but not me. <b>switch light back on</b></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
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固定位置的遮罩也可以用于捕获其外部的任何点击事件：

div.toShowTop {
  position: relative;
  z-index: 1;
  /* bring on top;*/
  box-shadow: 0 0 0 1600px rgba(0, 0, 0, 0.65);
  /* dark around it */
}
div.toShowTop ~.mask {
  position: fixed;
  top: 0;
  bottom: 0;
  right: 0;
  left: 50px;/* to see effect */
  background: rgba(0, 0, 0, 0.5);
}
body div.toShowTop {
  background: yellow;
  order: 1;
}
div:nth-child(8)~div {
  order: 2
}
/* demo purpose*/

body {
  display: flex;
  flex-wrap: wrap;
  counter-reset: divs -1;
  margin: 0;
}
div {
  counter-increment: divs;
  height: 120px;
  width: 120px;
  background: turquoise;
  cursor: pointer;
}
div:nth-child(odd) {
  background: tomato;
}
div:not(:first-of-type):before {
  content: counter(divs);
  display: block;
  font-size: 2em;
  margin: 1em;
  color: white;
}

<div tabindex="0" class="toShowTop">div to show</div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
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<b class="mask"></b>
<!-- can be generated via js -->

您也可以使用另一个元素的伪类，以避免额外的标记：

div.toShowTop {
  position:relative;
  z-index:1;/* bring on top;*/
}
div.toShowTop  + div:after {
  content:'';
  position:fixed;
  top:0;
  bottom:0;
  right:0;
  left:50px;
  background:rgba(0,0,0,0.75);
  cursor:auto;
}
body div.toShowTop {
  background:yellow;
  order:1;}
div:nth-child(8)~div {order:2}
/* demo purpose*/
body {
  display: flex;
  flex-wrap: wrap;
  counter-reset: divs -1;
  margin:0;
}
div {
  counter-increment: divs;
  height: 120px;
  width: 120px;
  background: turquoise;
  cursor:pointer;
  
}
div:nth-child(odd) {
  background: tomato;
}
div:not(:first-of-type):before {
  content: counter(divs);
  display: block;
  font-size: 2em;
  margin: 1em;
  color: white;
}

<div tabindex="0" class="toShowTop"> div to show </div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
<div tabindex="0"></div>
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- G-Cyrillus

Answer 2

你可以使用伪元素来实现...

div {
  background: #fff;
}

div:after {
  position: absolute;
  top: 0; bottom: 0; right: 0; left: 0;
  background: rgba(0,0,0,0.8);
  content: '';
  z-index: -1;
}

<div>div</div>

但更好的解决方案可能是创建一个单独的元素作为背景/遮罩。这将使您对布局拥有更多控制权。

section {
  background: white;
}

.mask {
  position: absolute;
  top: 0; bottom: 0; right: 0; left: 0;
  background: rgba(0,0,0,0.8);
  z-index: 1;
}

.show {
  position: relative;
  z-index: 2;
}

<section>section</section>

<section class="show">show this</section>

<section>section</section>

<div class="mask"></div>

- Michael Coker