为什么背景颜色与框阴影重叠？

Question

我有一个 table，其中的单元格有 background-color。我正在尝试为 thead 设置 box-shadow，但第一列中单元格的背景与阴影重叠。我尝试设置不同的 z-index 值和 position: relative，但无济于事。

.results-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    table-layout: fixed;
}

.results-table th,
.results-table td {
    padding: 1em;
    width: 96px;
    border-left: 1px solid rgba(34, 36, 38, 0.1);
    border-top: 1px solid rgba(34, 36, 38, 0.1);
}

.results-table thead {
  box-shadow: 0 2px 2px 0 rgba(0,0,0,.14), 0 3px 1px -2px rgba(0,0,0,.2), 0 1px 5px 0 rgba(0,0,0,.12);
  position: relative;
}

.results-table thead th {
    background: #E0E0E0;
    border-bottom: 1px solid rgba(34, 36, 38, 0.1);
}

.results-table tr:first-child td,
.results-table tr:first-child th {
    border-top: none;
}

.results-table tr th:first-child,
.results-table tr td:first-child {
    border-left: none;
}

.item-cell.item-cell {
    width: 128px;
}

td.item-cell.item-cell {
    background: lightgreen;
}

<table class="results-table">
  <thead>
    <tr>
      <th class="item-cell">
        Item
      </th>
      <th>
        Package
      </th>
      <th>
        Price
      </th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td class="item-cell">
        <a href="#">Link 1</a>
      </td>
      <td>Package 1</td>
      <td>Price 1</td>
    </tr>
    <tr>
      <td class="item-cell">
        <a href="#">Link 2</a>
      </td>
      <td>Package 2</td>
      <td>Price 2</td>
    </tr>
    <tr>
      <td class="item-cell">
        <a href="#">Link 3</a>
      </td>
      <td>Package 3</td>
      <td>Price 3</td>
    </tr>
  </tbody>
</table>

顺便说一句，阴影在 Firefox 中有效，但在其他浏览器中无效。

Firefox [image]

Chrome, Opera, Edge, IE11 [image]

那么如何为 thead 实现阴影？

谢谢。

Answer 1

在 td

上添加 z-index negative

.results-table td{
    position: relative;
    z-index: -1;
}

Answer 2

您可以更改它：

box-shadow: 0 2px 2px 0 rgba(0,0,0,.14), 0 3px 1px -2px rgba(0,0,0,.2), 0 1px 5px 0 rgba(0,0,0,.12);

对此：

box-shadow: 0 2px 2px 0 rgba(0,0,0,.14), 0 3px 1px -2px rgba(0,0,0,.2), 0 1px 5px 0 rgba(0,0,0,.12);
-webkit-box-shadow: 0 2px 2px 0 rgba(0,0,0,.14), 0 3px 1px -2px rgba(0,0,0,.2), 0 1px 5px 0 rgba(0,0,0,.12);
-moz-box-shadow: 0 2px 2px 0 rgba(0,0,0,.14), 0 3px 1px -2px rgba(0,0,0,.2), 0 1px 5px 0 rgba(0,0,0,.12);

Answer 3

对答案 # 2 点赞。但是这个老问题有新的解决方案，即 clip-path

body {
  background: #f7f7f7;
}
.container {
  width: 500px;
}

.item {
  background: #fff;
  height: 50px;
  box-shadow: inset 0 1px #000;
/*  Solution # 1 Starts */
/*   z-index: -1;
  position:relative */
/*  Solution # 1 Ends */
/*  Solution # 2 Starts */
  clip-path: inset(0 1px 1px);
/*  Solution # 2 End */
}

.cell {
  box-shadow: inset 0 -1px #000;
/*   box-shadow: 0 1px #000; */
}

<div class="container">
  <div class="cell">
    <div class="item">ITEM 1</div>
    <div class="item">ITEM 2</div>
    <div class="item">ITEM 3</div>
  </div>
</div>

为什么背景颜色与框阴影重叠？

Why background-color overlap the box-shadow?

html

css

html-table

css-tables