Try to using 1rem for float padding

Signed-off-by: Toomore Chiang <toomore@coscup.org>

docs_dev/docs/stylesheets/extra.css

@@ -1,5 +1,5 @@
 html.js-focus-visible.js body header.md-header.md-header--shadow nav.md-header__inner.md-grid {
-    padding: 0 .5rem;
+    padding: 0 1rem;
 }
 .center-table {
   text-align: center;