Problems setting styles

I am trying to set up a layout with tabs and a grid.
I’m setting the skins but they are not displaying correctly.
The tab bar is completely wrong and the lower panel has no color or border.
I’m using the css etc. from the Geo Explorer simple.
What is going wrong?
My code is below:

Geo explorer
<script src="./codebase/dhtmlx.js" type="text/javascript"></script>
<script src="" type="text/javascript" ></script>
html, body { width: 100%; height: 100%; }

You have such issue because skin “dhx_black” is out-of-date.
Today only 3 skins are supported on all the components: “skyblue”, “web” and “terrace”.
If you need a black color skin you can made it via dhtmlx Skin Builder (based on “skyblue”):