Button border test
HTML
<button>foooooooo</button>
CSS
body {
background: black;
padding:10px;
zoom:5;
}
button {
border:5px solid transparent;
border-radius:100px;
padding:10px;
_background:
linear-gradient(90deg, skyblue, white) padding-box,
linear-gradient(90deg, #f008, #f008) border-box;
background:
linear-gradient(#fff0) padding-box,
linear-gradient(90deg, #f008, #f008) border-box,
linear-gradient(90deg, skyblue, white) border-box;
}