This will hopefully be a growing list of various HTML+CSS layouts, components and techniques. The goal is to have a handy resource whenever needed and avoid having to start from scratch all the time or search the web for a solution.
Layouts
Single column layout
Two column layout
Two column layout with header
Three column layout
Three column layout with header
Headers
Header with search bar, menu and profile dropdown menu
Full page header with logo, slogan and menu
Footers
Footer with links and newsletter form
Menus
Simple responsive hamburger menu
Responsive multilevel pop-down menu