We’ll shoe you how to create some good looking CSS3 tabs with beveled corners. We’ll do that using a clever CSS3 gradients technique.

The idea

A while ago I read this wonderful article by Lea Verou about how to create beveled corners using CSS3 gradients. I found that very clever and we will use that technique in order to create our tabs.

The HTML

The purpose here, as usual, is to write clean and semantic markup: unordered list for the tabbed navigation and simple div‘s for wrapping content.

So, check the HTML below:

<ul id="tabs">
    <li><a href="#" title="tab1">One</a></li>
    <li><a href="#" title="tab2">Two</a></li>
    <li><a href="#" title="tab3">Three</a></li>
    <li><a href="#" title="tab4">Four</a></li>
</ul>

<div id="content">
    <div id="tab1">One - content</div>
    <div id="tab2">Two - content</div>
    <div id="tab3">Three - content</div>
    <div id="tab4">Four - content</div>
</div>

The CSS

Minimal and easy to update styles, also no images were used here:

#tabs
{
  overflow: auto;
  width: 100%;
  list-style: none;
  margin: 0;
  padding: 0;
}

#tabs li
{
    margin: 0;
    padding: 0;
    float: left;
}

#tabs a
{
    -moz-box-shadow: -4px 0 0 rgba(0, 0, 0, .2);
    -webkit-box-shadow: -4px 0 0 rgba(0, 0, 0, .2);
    box-shadow: -4px 0 0 rgba(0, 0, 0, .2);
    background: #ad1c1c;
    background:    -moz-linear-gradient(220deg, transparent 10px, #ad1c1c 10px);
    background:    -webkit-linear-gradient(220deg, transparent 10px, #ad1c1c 10px);
    background:     -ms-linear-gradient(220deg, transparent 10px, #ad1c1c 10px);
    background:      -o-linear-gradient(220deg, transparent 10px, #ad1c1c 10px);
    background:         linear-gradient(220deg, transparent 10px, #ad1c1c 10px);
    text-shadow: 0 1px 0 rgba(0,0,0,.5);
    color: #fff;
    float: left;
    font: bold 12px/35px 'Lucida sans', Arial, Helvetica;
    height: 35px;
    padding: 0 30px;
    text-decoration: none;
}

#tabs a:hover
{
    background: #c93434;
    background:    -moz-linear-gradient(220deg, transparent 10px, #c93434 10px);
    background:    -webkit-linear-gradient(220deg, transparent 10px, #c93434 10px);
    background:     -ms-linear-gradient(220deg, transparent 10px, #c93434 10px);
    background:      -o-linear-gradient(220deg, transparent 10px, #c93434 10px);
    background:         linear-gradient(220deg, transparent 10px, #c93434 10px);
}

#tabs a:focus
{
    outline: 0;
}

#tabs #current a
{
    background: #fff;
    background:    -moz-linear-gradient(220deg, transparent 10px, #fff 10px);
    background:    -webkit-linear-gradient(220deg, transparent 10px, #fff 10px);
    background:     -ms-linear-gradient(220deg, transparent 10px, #fff 10px);
    background:      -o-linear-gradient(220deg, transparent 10px, #fff 10px);
    background:         linear-gradient(220deg, transparent 10px, #fff 10px);
    text-shadow: none;
    color: #333;
}

#content
{
    background-color: #fff;
    background-image: -webkit-gradient(linear, left top, left bottom, from(#fff), to(#ddd));
    background-image: -webkit-linear-gradient(top, #fff, #ddd);
    background-image:    -moz-linear-gradient(top, #fff, #ddd);
    background-image:     -ms-linear-gradient(top, #fff, #ddd);
    background-image:      -o-linear-gradient(top, #fff, #ddd);
    background-image:         linear-gradient(top, #fff, #ddd);
    -moz-border-radius: 0 2px 2px 2px;
    -webkit-border-radius: 0 2px 2px 2px;
    border-radius: 0 2px 2px 2px;
    -moz-box-shadow: 0 2px 2px #000, 0 -1px 0 #fff inset;
    -webkit-box-shadow: 0 2px 2px #000, 0 -1px 0 #fff inset;
    box-shadow: 0 2px 2px #000, 0 -1px 0 #fff inset;
    padding: 30px;
}

/* Remove the rule below if you want the content to be "organic" */
#content div
{
    height: 220px;
}

Read more:http://www.red-team-design.com/css3-tabs-with-beveled-corners