revisiting CSS preprocessors.
SASS might have nice syntax, but keeping ruby available just for that is a hassle.
That leaves LESS or Stylus
both seem pretty good. Stylus is maybe a bit more sleek, but LESS is a lot more popular. I like that either can be compiled in the browser while developing. That simplifies things.,or.r_gc.r_pw.r_qf.&bvm=bv.43287494,d.aWc&fp=aa79bc8eab752bf1&biw=774&bih=850

these libraries look promising for making CSS more manageable:

I think I came across less being used with other javascript library... backbone.js.,or.r_gc.r_pw.r_qf.,cf.osb&fp=6444ccfd1295e99d
javascript drag item - Google Search
jquery - Javascript Drag and drop for touch devices - Stack Overflow,or.r_gc.r_pw.r_qf.,cf.osb&fp=6444ccfd1295e99d
javascript libraries comparison - Google Search
Compare JS MVC frameworks implementing the same site: TodoMVC | Hacker News
Javascript Graphs and Charts libraries | Comparison tables - SocialCompare
JavaScript library - Wikipedia, the free encyclopedia
Make the Web Faster — Google Developers
backbone js - Google Search
Projects and Companies using Backbone · documentcloud/backbone Wiki · GitHub
Zepto.js: the aerogel-weight jQuery-compatible JavaScript library
underscore js - Google Search
Sass - Syntactically Awesome Stylesheets
Compass Home | Compass Documentation
LESS « The Dynamic Stylesheet language
node js - Google Search
Node.js - Wikipedia, the free encyclopedia
Content delivery network - Wikipedia, the free encyclopedia

center page content
This will only work if the DOCTYPE is XHTML Transitional or Strict. IT WILL NOT WORK if your doctype is HTML 4.x. Here is an example of what it should look like:

Put this at the top of your CSS file and you will be good to go!
#html, body {
top: 0px;
right: 0px;
bottom: 0px;
left: 0px;
height: 100%;
margin: auto;

there seem to be many approaches these days for blocks with rounded corners.

there was one fully CSS version that draws one line rows along the top and bottom of the block with margins to give the rounded effect:

The rest use 2-4 images to get the effect
rounded corners css - Google Search
25 Rounded Corners Techniques with CSS
Spiffy Corners - Purely CSS Rounded Corners