New font pb

Hello,

I would like to add a new font to Mantra theme.
First, I’ve created a child theme.
I’ve tried to use Google font in the Mantra settings, it works properly on firefox but it’s not clean in the other navigators.

So I’ve generated the 4 files (eot, svg, tff, woff), I’ve put them in wp-includes/files repertory, I’ve added this code in my style.css of the child theme :

@font-face {
    font-family: 'quicksandbook';
    src: url('fonts/quicksand_book-webfont.eot');
    src: url('fonts/quicksand_book-webfont.eot?#iefix') format('embedded-opentype'),
         url('fonts/quicksand_book-webfont.woff') format('woff'),
         url('fonts/quicksand_book-webfont.ttf') format('truetype'),
         url('fonts/quicksand_book-webfont.svg#quicksandbook') format('svg');
    font-weight: normal;
    font-style: normal;
}

But it doesn’t work 🙁 Site url : http://www.cedricgournay.com
Thanks for your help !