the code and preview sections wont show scrolls when the text is overflown

[Coderx7]

As you can see in the picture below, the text is not showing, and there is no scroll at all either.

I have changed the wmd.css and added overflow-x:auto; to both code pre and .wmd-preview pre
so they look like this now :

.qa-q-view-content pre,
.qa-a-item-content pre,
.wmd-preview pre {
    overflow: auto;
    width: 100%;
    max-height: 400px;
    padding: 0;
    border-width: 1px 3px 1px 1px;
    border-style: solid;
    border-color: #ddd;
    background-color: #eee;
        overflow-x:auto;
}
code {
    direction: ltr;
}
pre code {
    display: block;
    padding: 8px;
    text-align: left;
    direction: ltr;
        overflow-x:auto;
}

yet nothing changes.
the irony is , if I change the css attributes using the browsers inspect element, adding the overflow-ax:auto fixes the problem, but the actual changes to the actual css seems not to be taken into account some how.