Improved sidebar, Added misc rules and options

Update index.php, sidebar.php, and 6 more files...

readme.md

@@ -1,6 +1,29 @@
 # NibblePoker's CSS Theme (W.I.P.)
 A simple and minimalist CSS stylesheet used across all my websites and web-based applications.
 
+## Structure
+This stylesheet is composed of 4 major parts that all work together towards a common goal
+all the while staying independent and usable individually if you ever wished to.
+
+### External
+The *External* rules regroup every external CSS stylesheets that are included in this one.\
+Currently, [reset.css](https://meyerweb.com/eric/tools/css/reset/) is the only such stylesheet.
+
+**See:** [scss/external/](scss/external)
+
+### Core
+The *Core* rules define mostly universal and portable CSS rules and other utilities for text,
+spacing and whatnot. \
+Internally, they are defined after everything else in order to let them override rules
+applied to the custom elements and site-centric rules.
+
+**See:** [scss/core/](scss/core)
+
+### Site
+
+### Custom
+
+
 
 ## License
 The code in this repository is released under [CC0 1.0 Universal (CC0 1.0) (Public Domain)](LICENSE-CC0)