[html] HTML table with 100% width, with vertical scroll inside tbody

I got it finally right with pure CSS by following these instructions:

http://tjvantoll.com/2012/11/10/creating-cross-browser-scrollable-tbody/

The first step is to set the <tbody> to display: block so an overflow and height can be applied. From there the rows in the <thead> need to be set to position: relative and display: block so that they’ll sit on top of the now scrollable <tbody>.

tbody, thead { display: block; overflow-y: auto; }

Because the <thead> is relatively positioned each table cell needs an explicit width

td:nth-child(1), th:nth-child(1) { width: 100px; }
td:nth-child(2), th:nth-child(2) { width: 100px; }
td:nth-child(3), th:nth-child(3) { width: 100px; }

But unfortunately that is not enough. When a scrollbar is present browsers allocate space for it, therefore, the <tbody> ends up having less space available than the <thead>. Notice the slight misalignment this creates...

The only workaround I could come up with was to set a min-width on all columns except the last one.

td:nth-child(1), th:nth-child(1) { min-width: 100px; }
td:nth-child(2), th:nth-child(2) { min-width: 100px; }
td:nth-child(3), th:nth-child(3) { width: 100px; }

Whole codepen example below:

CSS:

.fixed_headers {
  width: 750px;
  table-layout: fixed;
  border-collapse: collapse;
}
.fixed_headers th {
  text-decoration: underline;
}
.fixed_headers th,
.fixed_headers td {
  padding: 5px;
  text-align: left;
}
.fixed_headers td:nth-child(1),
.fixed_headers th:nth-child(1) {
  min-width: 200px;
}
.fixed_headers td:nth-child(2),
.fixed_headers th:nth-child(2) {
  min-width: 200px;
}
.fixed_headers td:nth-child(3),
.fixed_headers th:nth-child(3) {
  width: 350px;
}
.fixed_headers thead {
  background-color: #333333;
  color: #fdfdfd;
}
.fixed_headers thead tr {
  display: block;
  position: relative;
}
.fixed_headers tbody {
  display: block;
  overflow: auto;
  width: 100%;
  height: 300px;
}
.fixed_headers tbody tr:nth-child(even) {
  background-color: #dddddd;
}
.old_ie_wrapper {
  height: 300px;
  width: 750px;
  overflow-x: hidden;
  overflow-y: auto;
}
.old_ie_wrapper tbody {
  height: auto;
}

Html:

<!-- IE < 10 does not like giving a tbody a height.  The workaround here applies the scrolling to a wrapped <div>. -->
<!--[if lte IE 9]>
<div class="old_ie_wrapper">
<!--<![endif]-->

<table class="fixed_headers">
  <thead>
    <tr>
      <th>Name</th>
      <th>Color</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Apple</td>
      <td>Red</td>
      <td>These are red.</td>
    </tr>
    <tr>
      <td>Pear</td>
      <td>Green</td>
      <td>These are green.</td>
    </tr>
    <tr>
      <td>Grape</td>
      <td>Purple / Green</td>
      <td>These are purple and green.</td>
    </tr>
    <tr>
      <td>Orange</td>
      <td>Orange</td>
      <td>These are orange.</td>
    </tr>
    <tr>
      <td>Banana</td>
      <td>Yellow</td>
      <td>These are yellow.</td>
    </tr>
    <tr>
      <td>Kiwi</td>
      <td>Green</td>
      <td>These are green.</td>
    </tr>
    <tr>
      <td>Plum</td>
      <td>Purple</td>
      <td>These are Purple</td>
    </tr>
    <tr>
      <td>Watermelon</td>
      <td>Red</td>
      <td>These are red.</td>
    </tr>
    <tr>
      <td>Tomato</td>
      <td>Red</td>
      <td>These are red.</td>
    </tr>
    <tr>
      <td>Cherry</td>
      <td>Red</td>
      <td>These are red.</td>
    </tr>
    <tr>
      <td>Cantelope</td>
      <td>Orange</td>
      <td>These are orange inside.</td>
    </tr>
    <tr>
      <td>Honeydew</td>
      <td>Green</td>
      <td>These are green inside.</td>
    </tr>
    <tr>
      <td>Papaya</td>
      <td>Green</td>
      <td>These are green.</td>
    </tr>
    <tr>
      <td>Raspberry</td>
      <td>Red</td>
      <td>These are red.</td>
    </tr>
    <tr>
      <td>Blueberry</td>
      <td>Blue</td>
      <td>These are blue.</td>
    </tr>
    <tr>
      <td>Mango</td>
      <td>Orange</td>
      <td>These are orange.</td>
    </tr>
    <tr>
      <td>Passion Fruit</td>
      <td>Green</td>
      <td>These are green.</td>
    </tr>
  </tbody>
</table>

<!--[if lte IE 9]>
</div>
<!--<![endif]-->

EDIT: Alternative solution for table width 100% (above actually is for fixed width and didn't answer the question):

HTML:

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Color</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Apple</td>
      <td>Red</td>
      <td>These are red.</td>
    </tr>
    <tr>
      <td>Pear</td>
      <td>Green</td>
      <td>These are green.</td>
    </tr>
    <tr>
      <td>Grape</td>
      <td>Purple / Green</td>
      <td>These are purple and green.</td>
    </tr>
    <tr>
      <td>Orange</td>
      <td>Orange</td>
      <td>These are orange.</td>
    </tr>
    <tr>
      <td>Banana</td>
      <td>Yellow</td>
      <td>These are yellow.</td>
    </tr>
    <tr>
      <td>Kiwi</td>
      <td>Green</td>
      <td>These are green.</td>
    </tr>
  </tbody>
</table>

CSS:

table {
  width: 100%;
  text-align: left;
  min-width: 610px;
}
tr {
  height: 30px;
  padding-top: 10px
}
tbody { 
  height: 150px; 
  overflow-y: auto;
  overflow-x: hidden;
}
th,td,tr,thead,tbody { display: block; }
td,th { float: left; }
td:nth-child(1),
th:nth-child(1) {
  width: 20%;
}
td:nth-child(2),
th:nth-child(2) {
  width: 20%;
  float: left;
}
td:nth-child(3),
th:nth-child(3) {
  width: 59%;
  float: left;
}
/* some colors */
thead {
  background-color: #333333;
  color: #fdfdfd;
}
table tbody tr:nth-child(even) {
  background-color: #dddddd;
}

Demo: http://codepen.io/anon/pen/bNJeLO