why are my hyperlinks gray? twentytwelve

if someone can help with this ASAP i would appreciate. i have done everything i know to do to change the color of my hyperlinks in the styles.css file for this site lighthouseyogacenter.com — and they are still showing up mostly light grey which looks stupid. i really want them to be dark blue.

i have this in my child theme:

‘a:link{
text-decoration: underline;
color: #151B54;
}
a:link { color: #151B54; }
a:visited { color: #151B54; }
.a:hover { color: #151B54; }’

what is the problem? what can i do??? i need to fix this asap!!