HTML/CSS code won't stay

[frenchfilm]

Hello,

I am going crazy. I have a CMS Page with an intro text, followed by 3 images for 3 products, each with a "buy now" link below it. My goal is to display the intro text, then have the 3 images lined up and each with a link below it.

The WYSIWYG editor won't really help, especially for responsive design, so I use the code editor. I first created:

<p>TEXT</p>
<ul>
<li style="display: inline-block;">
<li style="display: inline-block;">
<li style="display: inline-block;">
</ul>

But for some reason, the "display: inline-block;" attribute won't stay. After I save and publish, it goes to the former style (stacked vertically), and "display: inline-block;" has disappeared. I tried this in other online live editors thinking there might be a problem (thought it's pretty basic), and it works perfectly, but in Prestashop, it just won't stay.

Help anyone?

Thanks.