In the example below you will find a wide variety of clips, HTML displays, login methods, vertical menus, and even the most popular themes of the moment: flat design (flattened image, flattened button shape, flattened user interface elements, etc.). Take a good look at these snippets of code, and if you incorporate them into your design, it will save you a lot of time, or you can think about learning something new from someone else and save it for a rainy day.
CSS3 Working Clock
This is a pure CSS3 clock. It uses CSS animations and graphics, without using any images or JS.
CSS3 Pricing Table
CSS Loader
Pure CSS3 MacBook Air with Thunderbird Display and Keyboard
Twitter Button Concept
CSS3 Loading Animation
Pure CSS3 Vertical Menu with Hover Effect
CSS3 Stamp effect using radial gradients
I Love Blur
Social Navigation
Login
Calendar
Social Footer
Parallax Landscape
CSS3 Thermometer
Css-only responsive Layout with Smooth transitions
Flat CSS3 Weather Widget
Flat Responsive Sliding Boxes
Tiny CSS3 Round Breadcrumb
CSS3 Hover Effect using:after psuedo Element
Flat UI Elements
CSS Flat Button Shapes
Email UI
Flat Icons CSS
Translation in Http://www.Flashuser.net/25-html-css-code-snippets-codepen
Popular HTML/CSS Code