body { text-align: center; }

.button {
background-color: #b8b2b2; /* Grey */
border: .5px solid #000000; /* Black */
color: black;
padding: 5px 10px;
text-align: center;
text-decoration: none;
display: inline-block;
font-size: 16px;
border-radius: 12px;
}

TR.separate-below TD,TR.separate-below TH {
    border-bottom: 1em solid white;
}