How can I use default Boostrap variables for styling?
For example (from bootstrap/scss/_variables.scss):
$font-size-base: 1rem !default; // Assumes the browser default, typically `16px`
$font-size-lg: $font-size-base * 1.25 !default;
$font-size-sm: $font-size-base * .875 !default;
$font-weight-lighter: lighter !default;
$font-weight-light: 300 !default;
$font-weight-normal: 400 !default;
$font-weight-bold: 700 !default;
$font-weight-bolder: bolder !default;