Overiding CSS. Is it better to override or recall all attributes

Overiding CSS. Is it better to override or recall all attributes

Is it better to do this:
.message_bookmark {
display: block;
height: 40px;
width: 40px;
position: relative;
left: 540px;
top: -168px;
opacity: 0.5;
}
.message_delete {
display: block;
height: 40px;
width: 40px;
position: relative;
left: 600px;
top: -128px;
opacity: 0.5;
}
or this:
.message_bookmark, .message_delete {
display: block;
height: 40px;
width: 40px;
position: relative;
left: 540px;
top: -168px;
opacity: 0.5;
}
.message_delete {
left: 600px;
top: -128px;
}
In terms of readability the second method is better suited and also uses
less code, so which is actually best?