/* Exemplo para Ubuntu */
@font-face {
    font-family: 'Ubuntu';
    src: url('ubuntu-regular.woff2') format('woff2'),
         url('ubuntu-regular.woff') format('woff');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Ubuntu';
    src: url('ubuntu-medium.woff2') format('woff2'),
         url('ubuntu-medium.woff') format('woff');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Ubuntu';
    src: url('ubuntu-bold.woff2') format('woff2'),
         url('ubuntu-bold.woff') format('woff');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

/* Exemplo para Open Sans */
@font-face {
    font-family: 'Open Sans';
    src: url('opensans-regular.woff2') format('woff2'),
         url('opensans-regular.woff') format('woff');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Open Sans';
    src: url('opensans-medium.woff2') format('woff2'),
         url('opensans-medium.woff') format('woff');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Open Sans';
    src: url('opensans-semibold.woff2') format('woff2'),
         url('opensans-semibold.woff') format('woff');
    font-weight: 600;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Open Sans';
    src: url('opensans-bold.woff2') format('woff2'),
         url('opensans-bold.woff') format('woff');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

/* Exemplo para Helvetica Neue */
@font-face {
    font-family: 'Helvetica Neue';
    src: url('helveticaneue-regular.woff2') format('woff2'),
         url('helveticaneue-regular.woff') format('woff');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Helvetica Neue';
    src: url('helveticaneue-medium.woff2') format('woff2'),
         url('helveticaneue-medium.woff') format('woff');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Helvetica Neue';
    src: url('helveticaneue-bold.woff2') format('woff2'),
         url('helveticaneue-bold.woff') format('woff');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

/* Nota: Não é necessário declarar @font-face para System UI, Arial e sans-serif, 
   pois são fontes do sistema */