Border-box sizing on the theme's own layout components

Without a framework reset, .wt-main (width 100% plus padding) was wider than a phone screen.

Claude-Session: https://claude.ai/code/session_01QhLkBGEip8wQdaZ54z4AqJ

weirsoe-theme.css

@@ -100,6 +100,8 @@ body::before {
 }
 
 /* ---------- responsive container ---------- */
+/* width:100% + padding must not overflow on pages without a framework reset (Bulma/Tailwind already do this) */
+.wt-container, .wt-main, .wt-header, .wt-nav, .wt-footer, .wt-card, .wt-input, .wt-btn, .wt-pre { box-sizing: border-box; }
 /* Full width (with gutters) on small screens; a centred max-width column on
    larger ones. Use --wt-container / --modifier to control the breakpoint width. */
 .wt-container {