Merhaba,

Mobil
@media only screen and (max-width: 720px) {
.bb-post-meta{font-size:16px;line-height:1em; margin-left: 19.5%;} 
}
Tablet
@media only screen and (min-width: 720px) and (max-width: 1024px) {
.bb-post-meta{font-size:16px;line-height:1em; margin-top: 5%;} 
}
Masaüstü
@media only screen and (min-width: 1024px)  {
.bb-post-meta{font-size:16px;line-height:1em;} 
}