.cooperation_button
position: relative
border-radius: 4px
border: 1.5px solid #2EECC5
background: #161617
z-index: 11
&::after
position: absolute
content: " "
width: 100%
height: 100%
border-radius: 4px
border: 1.5px solid rgba(46, 236, 197, 0.40)
left: 9px
top: 11px
z-index: -1