3D 按钮
btn-3d
带图标遮罩层的按钮
btn-icon-overlay
圆角按钮
btn-circle
带填充动画的按钮
fill-top
fill-right
fill-bottom
fill-left
更多按钮颜色
btn-green
btn-blue
btn-purple
btn-orange
btn-dirty-green
btn-aqua
btn-grey
社交网站颜色按钮
btn-facebook
btn-twitter
btn-pinterest
btn-youtube
btn-linkedin
btn-google-plus