How to Customize CSS in Blogspot. The Blogger Template Designer allows you to insert custom CSS code to change your blog's appearance. ... as it will not alter your blog's core HTML design.

Tumblr lets users edit their page designs with CSS and HTML customization. Users of Tumblr also may want to share and embed their Tumblr blogs onto other websites, a feature Tumblr allows and ...

While HTML, CSS and JavaScript are powerful tools, they tend to run out of steam with development of advanced web applications that store data on the client side and manage complex state transitions.