Fix modal focus trapping and add focus indicators

Focus trapping:
- Manually handle all Tab key navigation within modals
- Use getComputedStyle and offsetWidth/Height to detect visible elements
- Focus appropriate input field when modal opens (PIN or Name)

Focus indicators:
- Add visible outline on buttons (:focus)
- Add visible outline on checkbox (:focus)
- Add visible outline on modal close button (:focus)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

index.html

@@ -331,6 +331,11 @@
             background: var(--border);
         }
 
+        .modal-close:focus {
+            outline: 2px solid var(--forest);
+            outline-offset: 2px;
+        }
+
         .modal-body {
             padding: 24px;
         }
@@ -405,6 +410,11 @@
             background: var(--terracotta-light);
         }
 
+        .btn:focus {
+            outline: 3px solid var(--oak);
+            outline-offset: 2px;
+        }
+
         .btn-secondary {
             background: var(--cream);
             color: var(--charcoal);
@@ -427,6 +437,11 @@
             accent-color: var(--forest);
         }
 
+        .checkbox-group input:focus {
+            outline: 2px solid var(--forest);
+            outline-offset: 2px;
+        }
+
         .pin-input {
             letter-spacing: 8px;
             text-align: center;
@@ -1156,11 +1171,23 @@
             // Make background content inert (unfocusable)
             document.getElementById('mainContent').setAttribute('inert', '');
 
-            // Focus first focusable element in modal
+            // Focus the primary input field in the modal
             setTimeout(() => {
-                const focusable = getFocusableElements(modal);
-                if (focusable.length > 0) {
-                    focusable[0].focus();
+                let focusTarget = null;
+                if (id === 'pinModal') {
+                    focusTarget = document.getElementById('pinInput');
+                } else if (id === 'setPinModal') {
+                    focusTarget = document.getElementById('newPinInput');
+                } else if (id === 'itemModal') {
+                    focusTarget = document.getElementById('itemName');
+                }
+                if (focusTarget) {
+                    focusTarget.focus();
+                } else {
+                    const focusable = getFocusableElements(modal);
+                    if (focusable.length > 0) {
+                        focusable[0].focus();
+                    }
                 }
             }, 50);
 
@@ -1184,11 +1211,15 @@
         }
 
         function getFocusableElements(container) {
-            const elements = container.querySelectorAll('button, input:not([type="hidden"]), select, textarea, [tabindex]:not([tabindex="-1"])');
-            return Array.from(elements).filter(el => {
+            const selector = 'button, input:not([type="hidden"]), select, textarea, [tabindex]:not([tabindex="-1"])';
+            const elements = Array.from(container.querySelectorAll(selector));
+            return elements.filter(el => {
                 if (el.disabled) return false;
+                // Check if element is visible
+                if (el.offsetWidth === 0 && el.offsetHeight === 0) return false;
                 const style = window.getComputedStyle(el);
-                return style.display !== 'none' && style.visibility !== 'hidden';
+                if (style.display === 'none' || style.visibility === 'hidden') return false;
+                return true;
             });
         }
 
@@ -1203,21 +1234,22 @@
                 return;
             }
 
-            // Trap focus on Tab
+            // Handle all Tab navigation manually
             if (e.key === 'Tab') {
+                e.preventDefault();
                 const focusable = getFocusableElements(modal);
                 if (focusable.length === 0) return;
 
-                const first = focusable[0];
-                const last = focusable[focusable.length - 1];
+                const currentIndex = focusable.indexOf(document.activeElement);
+                let nextIndex;
 
-                if (e.shiftKey && document.activeElement === first) {
-                    e.preventDefault();
-                    last.focus();
-                } else if (!e.shiftKey && document.activeElement === last) {
-                    e.preventDefault();
-                    first.focus();
+                if (e.shiftKey) {
+                    nextIndex = currentIndex <= 0 ? focusable.length - 1 : currentIndex - 1;
+                } else {
+                    nextIndex = currentIndex >= focusable.length - 1 ? 0 : currentIndex + 1;
                 }
+
+                focusable[nextIndex].focus();
             }
         }