Add visual button presets, jump targets and menu controls

scripts/build-buttons.mjs

@@ -0,0 +1,5 @@
+import { readFile, writeFile } from 'node:fs/promises';
+const file = new URL('../public/assets/buttons.css', import.meta.url);
+const source = (await readFile(file, 'utf8')).split('/* Responsive variants */')[0].trimEnd();
+const rules = source.split('\n').filter(line => line.includes('b-desktop-')).join('\n');
+await writeFile(file, `${source}\n/* Responsive variants */\n@media(max-width:1024px){\n${rules.replaceAll('b-desktop-', 'b-tablet-')}\n}\n@media(max-width:767px){\n${rules.replaceAll('b-desktop-', 'b-mobile-')}\n}\n`);