feat: toolbar sections as dropdown menus

Replace horizontal toolbar sections with dropdown buttons (I/O, Gates,
Components). Each opens a dropdown menu on click, keeping the toolbar
clean and compact. Dropdowns close on outside click or after selecting
a gate.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

css/style.css

@@ -78,7 +78,7 @@ body {
 .gate-btn.output-btn { border-color: #ff8833; }
 .gate-btn.output-btn:hover { border-color: #ffaa55; }
 
-.separator { width: 1px; height: 32px; background: #2a2a3a; margin: 0 6px; }
+.separator { width: 1px; height: 24px; background: #2a2a3a; margin: 0 4px; }
 
 .create-component-btn {
     padding: 4px 10px;
@@ -111,56 +111,107 @@ body {
 .action-btn.sim-btn:hover { background: #ff44aa22; }
 .action-btn.sim-btn.active { background: #ff44aa33; border-color: #ff66cc; color: #ff66cc; }
 
-/* ==================== Toolbar Sections ==================== */
-.toolbar-section {
-    display: flex;
-    flex-direction: column;
-    align-items: flex-start;
-    gap: 2px;
-    padding: 4px 0;
+/* ==================== Toolbar Dropdowns ==================== */
+.toolbar-dropdown {
+    position: relative;
 }
 
-.section-label {
-    font-size: 8px;
-    color: #555;
-    font-weight: 600;
-    text-transform: uppercase;
-    letter-spacing: 0.5px;
-    padding: 0 2px;
-    line-height: 1;
-}
-
-.section-buttons {
-    display: flex;
-    gap: 3px;
-    align-items: center;
-    flex-wrap: nowrap;
-}
-
-.toolbar-section .gate-btn {
-    padding: 4px 10px;
-    font-size: 11px;
-}
-
-.toolbar-section #saved-components {
-    display: flex;
-    gap: 3px;
-    align-items: center;
-}
-
-.toolbar-section .component-btn {
-    padding: 4px 10px;
-    font-size: 11px;
+.dropdown-toggle {
+    padding: 6px 14px;
     background: #1a1a2e;
     border: 1px solid #2a2a3a;
     border-radius: 6px;
+    color: #ccc;
+    cursor: pointer;
+    font-size: 12px;
+    font-weight: 600;
+    transition: all 0.15s;
+    user-select: none;
+    display: flex;
+    align-items: center;
+    gap: 6px;
+}
+
+.dropdown-toggle:hover {
+    background: #252540;
+    border-color: #00e599;
+    color: #fff;
+}
+
+.toolbar-dropdown.open .dropdown-toggle {
+    background: #252540;
+    border-color: #00e599;
+    color: #00e599;
+}
+
+.dropdown-arrow {
+    font-size: 10px;
+    opacity: 0.6;
+    transition: transform 0.15s;
+}
+
+.toolbar-dropdown.open .dropdown-arrow {
+    transform: rotate(180deg);
+    opacity: 1;
+}
+
+.dropdown-menu {
+    display: none;
+    position: absolute;
+    top: calc(100% + 6px);
+    left: 0;
+    min-width: 140px;
+    background: #14141e;
+    border: 1px solid #2a2a3a;
+    border-radius: 8px;
+    padding: 4px;
+    z-index: 150;
+    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
+    flex-direction: column;
+    gap: 2px;
+}
+
+.toolbar-dropdown.open .dropdown-menu {
+    display: flex;
+}
+
+.dropdown-menu .gate-btn {
+    width: 100%;
+    text-align: left;
+    padding: 7px 12px;
+    border-radius: 5px;
+    font-size: 12px;
+}
+
+.dropdown-menu .create-component-btn {
+    width: 100%;
+    text-align: left;
+    padding: 7px 12px;
+    border-radius: 5px;
+    font-size: 12px;
+}
+
+.dropdown-menu #saved-components {
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+}
+
+.dropdown-menu .component-btn {
+    width: 100%;
+    text-align: left;
+    padding: 7px 12px;
+    background: #1a1a2e;
+    border: 1px solid #2a2a3a;
+    border-radius: 5px;
     color: #9900ff;
     cursor: pointer;
+    font-size: 12px;
     font-weight: 600;
     transition: all 0.15s;
 }
 
-.toolbar-section .component-btn:hover {
+.dropdown-menu .component-btn:hover {
     border-color: #9900ff;
     color: #cc66ff;
     background: #252540;

index.html

@@ -10,22 +10,20 @@
     <div id="toolbar">
         <span class="logo">⚡ Logic Lab</span>
 
-        <!-- I/O Section -->
-        <div class="toolbar-section">
-            <div class="section-label">I/O</div>
-            <div class="section-buttons">
+        <!-- I/O Dropdown -->
+        <div class="toolbar-dropdown">
+            <button class="dropdown-toggle">I/O <span class="dropdown-arrow">▾</span></button>
+            <div class="dropdown-menu">
                 <button class="gate-btn input-btn" data-gate="INPUT">INPUT</button>
                 <button class="gate-btn clock-btn" data-gate="CLOCK">CLOCK</button>
                 <button class="gate-btn output-btn" data-gate="OUTPUT">OUTPUT</button>
             </div>
         </div>
 
-        <div class="separator"></div>
-
-        <!-- Gates Section -->
-        <div class="toolbar-section">
-            <div class="section-label">Gates</div>
-            <div class="section-buttons">
+        <!-- Gates Dropdown -->
+        <div class="toolbar-dropdown">
+            <button class="dropdown-toggle">Gates <span class="dropdown-arrow">▾</span></button>
+            <div class="dropdown-menu">
                 <button class="gate-btn" data-gate="AND">AND</button>
                 <button class="gate-btn" data-gate="OR">OR</button>
                 <button class="gate-btn" data-gate="NOT">NOT</button>
@@ -35,19 +33,15 @@
             </div>
         </div>
 
-        <div class="separator"></div>
-
-        <!-- Components Section -->
-        <div class="toolbar-section" id="components-section">
-            <div class="section-label">Components</div>
-            <div class="section-buttons">
+        <!-- Components Dropdown -->
+        <div class="toolbar-dropdown" id="components-section">
+            <button class="dropdown-toggle">Components <span class="dropdown-arrow">▾</span></button>
+            <div class="dropdown-menu" id="components-menu">
                 <button class="create-component-btn" id="create-component-btn" title="Create custom component">✚ Create</button>
                 <div id="saved-components"></div>
             </div>
         </div>
 
-        <div class="separator"></div>
-
         <button class="action-btn sim-btn" id="sim-btn">Waveform</button>
         <div class="toolbar-right">
             <button class="action-btn export-btn" id="export-btn" title="Export circuit">↓ Export</button>

js/components.js

@@ -286,6 +286,8 @@ export function updateComponentButtons() {
         btn.addEventListener('click', (e) => {
             e.stopPropagation();
             state.placingGate = `COMPONENT:${comp.id}`;
+            // Close dropdown
+            document.querySelectorAll('.toolbar-dropdown.open').forEach(d => d.classList.remove('open'));
         });
         container.appendChild(btn);
     });

js/events.js

@@ -215,9 +215,32 @@ export function initEvents() {
         keysDown.delete(e.key);
     });
 
-    // ==================== TOOLBAR ====================
-    document.querySelectorAll('.gate-btn').forEach(btn => {
-        btn.addEventListener('click', () => {
+    // ==================== TOOLBAR DROPDOWNS ====================
+    function closeAllDropdowns() {
+        document.querySelectorAll('.toolbar-dropdown.open').forEach(d => d.classList.remove('open'));
+    }
+
+    document.querySelectorAll('.dropdown-toggle').forEach(toggle => {
+        toggle.addEventListener('click', (e) => {
+            e.stopPropagation();
+            const dropdown = toggle.parentElement;
+            const wasOpen = dropdown.classList.contains('open');
+            closeAllDropdowns();
+            if (!wasOpen) dropdown.classList.add('open');
+        });
+    });
+
+    // Close dropdowns when clicking outside
+    document.addEventListener('click', (e) => {
+        if (!e.target.closest('.toolbar-dropdown')) {
+            closeAllDropdowns();
+        }
+    });
+
+    // Gate buttons inside dropdowns
+    document.querySelectorAll('.dropdown-menu .gate-btn').forEach(btn => {
+        btn.addEventListener('click', (e) => {
+            e.stopPropagation();
             const gateName = btn.dataset.gate;
             // In puzzle mode, check if gate is allowed
             if (puzzleMode && currentLevel) {
@@ -228,6 +251,7 @@ export function initEvents() {
                 }
             }
             state.placingGate = gateName;
+            closeAllDropdowns();
         });
     });
 
@@ -332,7 +356,9 @@ export function initEvents() {
     document.addEventListener('mouseup', () => { state.resizingWave = false; });
 
     // ==================== COMPONENT EDITOR ====================
-    document.getElementById('create-component-btn').addEventListener('click', () => {
+    document.getElementById('create-component-btn').addEventListener('click', (e) => {
+        e.stopPropagation();
+        closeAllDropdowns();
         enterComponentEditor();
     });