Update font in cosmo.scss

Source Sans Pro is now known as Source Sans 3. But the real reason I make this change is to include the italic: otherwise, any Quarto document has rather ugly-looking automatically-generated italic letters (slanted versions of the upright).

Author: lynn

src/resources/formats/html/bootstrap/themes/cosmo.scss

@@ -52,7 +52,7 @@ $body-color:    $gray-800 !default;
 // Fonts
 
 // stylelint-disable-next-line value-keyword-case
-$font-family-sans-serif:    "Source Sans Pro", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol" !default;
+$font-family-sans-serif:    "Source Sans 3", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol" !default;
 $headings-font-weight:      400 !default;
 
 // Navbar
@@ -75,7 +75,7 @@ $progress-height:               .5rem !default;
 
 // Variables
 
-$web-font-path: "https://fonts.googleapis.com/css2?family=Source+Sans+Pro:wght@300;400;700&display=swap" !default;
+$web-font-path: "https://fonts.googleapis.com/css2?family=Source+Sans+3:ital,wght@0,200..900;1,200..900&display=swap" !default;
 @if $web-font-path {
   @import url($web-font-path);
 }