Add power conversion entries and responsive nav tweaks

hdyc-svelte/src/routes/+layout.svelte

@@ -307,12 +307,28 @@
       updateTheme(event.matches ? 'dark' : 'light');
     };
 
+    const navBreakpoint = window.matchMedia('(max-width: 1024px)');
+    const handleNavBreakpoint = (event: MediaQueryListEvent) => {
+      if (event.matches) {
+        sidebarOpen = false;
+      }
+    };
+
+    if (navBreakpoint.matches) {
+      sidebarOpen = false;
+    }
+
     const cleanup = () => {
       if ('removeEventListener' in mediaQuery) {
         mediaQuery.removeEventListener('change', handlePreferenceChange);
       } else {
         mediaQuery.removeListener(handlePreferenceChange);
       }
+      if ('removeEventListener' in navBreakpoint) {
+        navBreakpoint.removeEventListener('change', handleNavBreakpoint);
+      } else {
+        navBreakpoint.removeListener(handleNavBreakpoint);
+      }
     };
 
     if ('addEventListener' in mediaQuery) {
@@ -321,6 +337,12 @@
       mediaQuery.addListener(handlePreferenceChange);
     }
 
+    if ('addEventListener' in navBreakpoint) {
+      navBreakpoint.addEventListener('change', handleNavBreakpoint);
+    } else {
+      navBreakpoint.addListener(handleNavBreakpoint);
+    }
+
     return cleanup;
   });
 </script>
@@ -343,7 +365,14 @@
 <header class="site-header">
   <div style="display:flex;align-items:center;gap:0.75rem;">
     {#if !isHomepage}
-      <button class="hamburger" on:click={() => (sidebarOpen = !sidebarOpen)} aria-label="Toggle menu">
+      <button
+        type="button"
+        class="hamburger"
+        on:click={() => (sidebarOpen = !sidebarOpen)}
+        aria-label="Toggle menu"
+        aria-controls="site-navigation"
+        aria-expanded={sidebarOpen ? 'true' : 'false'}
+      >
         ☰
       </button>
     {/if}