@font-face {
        font-family: 'Helvetica';
        font-display: swap;
        src: url('../fonts/HelveticaNeueLTStd-Roman.otf') format('truetype');
    }     
    @font-face {
        font-family: 'Helvetica_bold';
        font-display: swap;
        src: url('../fonts/HelveticaNeueLTStd-Bd.otf') format('truetype');
    } 
    @font-face {
        font-family: 'Helvetica_bolder';
        font-display: swap;
        src: url('../fonts/HelveticaNeueLTStd-Blk.otf') format('truetype');
    } 
    * {
        font-family: 'Helvetica', sans-serif;
        font-weight: 400;
    }
    .helvetica_bold {
        font-family: 'Helvetica_bold', sans-serif;
    }
    .helvetica_bolder {
        font-family: 'Helvetica_bolder', sans-serif;
    }