Here are some CSS close button examples.
Animated close icon
Dev: ross s
Open / Close button animation
Dev: Jerome Renders
Open / Close
Dev: Jonathan Blair
Back To Close by Ste
Dev: Stefano
Close button
Dev: merrybottle
Twitter close button alternative
Dev: Ana Tudor
Close button
Dev: Antonio Grosz
CSS only close button
Dev: Zach Wolf
Close Button
Dev: Jermbo
Close Animation
Dev: Maneesh
Close button
Dev: Caleb Duren
Close button
Dev: Paraskevas Dinakis
Open / Close button with animation
Dev: Murphy Randle
Close Button
Dev: Natalie
Pure CSS cross / close button @mixin
Dev: Cyril Lamotte
CSS close button
Dev: Dipta J. Basu
Pure css close button
Dev: Carson
Pure Css Close Button
Dev: ilker Yılmaz
Pure CSS Close Button
Dev: spinab
CSS Close Button for Lightbox
Dev: Weston Johnson
Simple pure css close button
Dev: Marvin van Kalsbeek