Question

I am trying to make the active list item look like this:

This is what I currently have (the blue triangle is a right triangle instead of an obtuse isosceles):

Here is my HTML:

<ul class="guideList">
    <li><a>Consulting</a></li>
    <li class="active">Law<span class="activePointer"></span></li>
    <li><a>Finance</a></li>
    <li><a>Technology</a></li>
</ul>

Here is my CSS:

.guideList{
    font-size: 12px;
    line-height: 12px;
    font-weight: bold;
    list-style-type: none;
    margin-top: 10px;
    width: 125px;
}

.guideList li{
    padding: 5px 0px 5px 10px;
}

.guideList .active{
    background-color: #0390d1;
    color: white;
}

.guideList .activePointer{
    margin-top: -5px;
    margin-bottom: -5px;
    float: right;
    display: inline-block;
    width: 0px;
    height: 0px;
    border-top: 11px solid white;
    border-left: 11px solid transparent;
    border-bottom: 11px solid white;
}

jsFiddle

How do I fix this?

ETA I tried @jlbruno’s idea (decreasing the size of the left border), but when I do that the lines of the triangle are not sharp:

ETA Using transform:rotate fixed the edges (thank you @jlbruno!)…but not for IE8. I tried using the microsoft matrix transform filter (related SO question) but it didn’t help. How do I get this to work in IE8 also?
Here is the CSS I tried for IE8:

 -ms-filter: "progid:DXImageTransform.Microsoft.Matrix(M11=0.9999996192282494, M12=-0.0008726645152362283, M21=0.0008726645152362283, M22=0.9999996192282494, SizingMethod='auto expand')";

Answer 1

Change the border-left on .guideList .activePointer to something like 7px instead of 11… the more you drop that value, the wider the angle will get.

.guideList .activePointer{
    margin-top: -5px;
    margin-bottom: -5px;
    float: right;
    display: inline-block;
    width: 0px;
    height: 0px;
    border-top: 11px solid white;
    border-left: 7px solid transparent;
    border-bottom: 11px solid white;
    -webkit-transform: rotate(0.05deg); // added to smooth edges in Chrome
}