d` element
$font-size-btn: $font-size-base;          // font size of buttons

$font-size-h1: 3rem;                      // font size of headings
$font-size-h2: 2rem;
$font-size-h3: 1.5rem;
$font-size-h4: 1.4rem;
$font-size-h5: 1.3rem;
$font-size-h6: 1.2rem;

$font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
$font-family-headings: $font-family-base;
$font-family-monospace: Consolas, 'Liberation Mono', Menlo, Courier, monospace;

$font-weight-light: 100;  