关于伪前后元素的CSS3 Box-shadow

Question

我需要创建这样的东西来分离移动设计中的部分：

我可以使用CSS轻松创建有角度的部分，但我很难让盒子阴影正确。问题是，我只需要在伪元素之前的底部的盒子阴影。但它被添加到所有方面，所以当两个元素在中间相遇以形成点时，盒阴影重叠。

见这里例如：

这是我到目前为止（jsfiddle：https://jsfiddle.net/47zqjzmf/1/）

HTML：

<div class="wrapper">
  <div class="inner"></div>
</div>

CSS：

.wrapper {
  display: inline-block;
  background: #fff;
  width: 300px;
  height: 300px;
  overflow: hidden;
}

.inner {
  position: relative;
  background: lightblue;
  width: 100%;
  height: 120px;
}

.inner:before, .inner:after {
    content: '';
    position: absolute;
    bottom: -10px;
    width: calc(50% + 5px);
    height: 20px;
    background-color: #fff;
    box-shadow: 1px 1px 10px 1px #000;
}

.inner:before {
  left: -2px;
  transform: rotate(7deg);
}

.inner:after {
  right: -2px;
  transform: rotate(-7deg);
}

关于如何实现这种效果的任何建议？

Answer 1

box-shadow对你没有帮助，因为正如属性名称所说，它是盒子。对你有帮助的是filter: drop-shadow()。此外，您可以使用clip-path属性来代替创建这两个伪元素矩形。

.element {
  width: 300px;
  color: white;
  filter: drop-shadow(0 0 15px black);
}

.element__clip {
  -webkit-clip-path: polygon(100% 0, 100% 80%, 50% 100%, 0 80%, 0 0);
  clip-path: polygon(100% 0, 100% 80%, 50% 100%, 0 80%, 0 0);
  background: blue;
}

<div class="element">
  <div class="element__clip">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Praesent ultrices, lorem id pellentesque sollicitudin, mauris massa aliquam velit, ut sagittis tellus justo non turpis. In tempor at dui et placerat. Aliquam dolor lorem, maximus non nunc sit amet, condimentum aliquam neque. Suspendisse potenti. Aliquam laoreet purus sed arcu elementum varius. Nullam ante tortor, elementum sit amet justo vel, mollis dapibus massa. Sed ultricies dapibus eros ac laoreet. Maecenas posuere arcu enim, non interdum ipsum vulputate nec. Nulla iaculis orci ac mattis accumsan. Praesent id auctor ipsum. Aenean cursus arcu placerat nunc consectetur, feugiat tincidunt felis placerat. Quisque id sagittis mi. Curabitur tincidunt consequat orci, eu congue metus ultrices at. Aenean luctus justo et pharetra tristique.</div>
</div>

Answer 2

尝试向阴影的X轴添加不同的值，以使它们不重叠。

.inner:before {box-shadow: -2px 2px 3px 1px rgba(0,0,0,.1)}
.inner:after {box-shadow: 2px 2px 3px 1px rgba(0,0,0,.1)}

body {
  position: relative;
  text-align: center;
}

.wrapper {
  display: inline-block;
  background: #fff;
  width: 300px;
  height: 300px;
  overflow: hidden;
}

.inner {
  position: relative;
  background: lightblue;
  width: 100%;
  height: 120px;
}

.inner:before, .inner:after {
    content: '';
    position: absolute;
    bottom: -10px;
    width: calc(50% + 5px);
    height: 20px;
    background-color: #fff;
}
.inner:before {
      box-shadow: -2px 2px 3px 1px rgba(0,0,0,.1);
}
.inner:after {
      box-shadow: 2px 2px 3px 1px rgba(0,0,0,.1);
}

.inner:before {
    left: -2px;
    -webkit-transform: rotate(7deg);
    -moz-transform: rotate(7deg);
    -ms-transform: rotate(7deg);
    -o-transform: rotate(7deg);
    transform: rotate(7deg);
}

.inner:after {
  right: -2px;
    -webkit-transform: rotate(-7deg);
    -moz-transform: rotate(-7deg);
    -ms-transform: rotate(-7deg);
    -o-transform: rotate(-7deg);
    transform: rotate(-7deg);
}

<div class="wrapper">
  <div class="inner"></div>
</div>

Answer 3

试试这个：

.inner:before, .inner:after {
    content: '';
    position: absolute;
    bottom: -10px;
    width: calc(50% + 5px);
    height: 20px;
    background-color: #fff;
    box-shadow: 3px 4px 4px -1px #000000;
}

https://jsfiddle.net/47zqjzmf/2/

Answer 4

尝试使用渐变背景的不同解决方案。它不像三角形阴影，但仍然看起来像下面的div。

＆＃13;

＆＃13;

body {
  position: relative;
  text-align: center;
}

.wrapper {
  display: inline-block;
  background: #fff;
  width: 300px;
  height: 300px;
  overflow: hidden;
}

.inner {
  position: relative;
  background: lightblue;
  width: 100%;
  height: 120px;
}

.inner:before, .inner:after {
    content: '';
    position: absolute;
    bottom: -10px;
    width: calc(50% + 5px);
    height: 20px;
    background-color: #fff;
}

.inner:before {
  left: -2px;
  transform: rotate(7deg);
}

.inner:after {
  right: -2px;
  transform: rotate(-7deg);
}


.content {
  padding: 20px;
/* Permalink - use to edit and share this gradient: http://colorzilla.com/gradient-editor/#cccccc+0,ffffff+15,000000+100&0.65+0,0+100 */
background: -moz-linear-gradient(top, rgba(204,204,204,0.65) 0%, rgba(255,255,255,0.55) 15%, rgba(0,0,0,0) 100%); /* FF3.6-15 */
background: -webkit-linear-gradient(top, rgba(204,204,204,0.65) 0%,rgba(255,255,255,0.55) 15%,rgba(0,0,0,0) 100%); /* Chrome10-25,Safari5.1-6 */
background: linear-gradient(to bottom, rgba(204,204,204,0.65) 0%,rgba(255,255,255,0.55) 15%,rgba(0,0,0,0) 100%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#a6cccccc', endColorstr='#00000000',GradientType=0 ); /* IE6-9 */
}

＆＃13;

<div class="wrapper">
  <div class="inner"></div>
  <div class="content">
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
  </div>
</div>

＆＃13;

＆＃13;

＆＃13;