fix: mermaid copy source position

Jacky Zhao

2023-09-24 ea5742c328c97a20f7add4994aa7e443fc6f7f39

 quartz/styles/variables.scss

@@ -1,5 +1,6 @@
$pageWidth: 800px;
$pageWidth: 750px;
$mobileBreakpoint: 600px;
$tabletBreakpoint: 1200px;
$sidePanelWidth: 400px;
$sidePanelWidth: 380px;
$topSpacing: 6rem;
$fullPageWidth: $pageWidth + 2 * $sidePanelWidth;