My some single div solutions:

• Transparent arrow/triangle indented over an image
• How to add text in the center of a progress bar and color it depending on the progress value with CSS?
• Transparent hollow or cut out circle
• div with triangle at the bottom with background image
• Hover effect : expand bottom border
• Incomplete borders around div
• CSS pie chart with background pattern
• Diagonal Line CSS
• curved shape with curved line with blur effect CSS
• How to make a curved shape with gradient?
• Draw an X in CSS
• Border fade in circle