Common reference networks for HTML5 and CSS3

When we use HTML5, CSS3, and even bootstrap to design the site, there are some aspects that must be considered, such as font size, title size, line spacing, number of words per line, font, color, background image and text collocation, icons, left white and layout ... All these, are not casually, pay attention to certain principles. And these principles usually refer to some websites. These sites are listed below.

HTML5 and CSS3 commonly used reference sites?

Browser rendering complies with HTML5 standard: http://necolas.github.io/normalize.css/

Google Fonts: ttps://www.google.com/fonts

Grid: http://www.responsivegridsystem.com/

Flat color: http://flatuicolors.com/

Select color Value: http://www.0to255.com/

Icon: http://ionicons.com/

css:https://css-tricks.com/

JS's cdn:http://www.jsdelivr.com/

The compatibility of a CSS property in each browser: http://caniuse.com/

Create favicon:http://realfavicongenerator.net/

Compress picture size: http://optimizilla.com/

CSS file minimization: www.minifycss.com

JS file minimization: htp://www.minifyjavascript.com/

Detecting HTML code: http://validator.w3.org/

Common reference networks for HTML5 and CSS3