Hi, you don't need to use CSS at all. If you don't want the numbers to show up, open up the slides.js code and make this change. Note that I'm assuming you're using the latest, minfied version of slides.js - version 3.0.
Find in code: .appendTo(e),d=a("<a>",{href:"#","data-slidesjs-item":b,html:b+1})
Change to: .appendTo(e),d=a("<a>",{href:"#","data-slidesjs-item":b /*,html:b+1*/ })
You're slides will still function, but the anchor tags in each list item won't contain the slide number. Make sure you comment out the comma directly after 'b' value. Also, since you;re not changing the href value for each anchor tag, you can still click on each one to move to that slide.