Replace sections with tabs, add device card to grid

- Switch Devices/Displays from collapsible sections to tab layout
- Remember active tab in localStorage
- Re-render display layout when switching to Displays tab
- Replace floating "+" button with dashed add-device card in grid
- Rename sections to "Devices" and "Displays"

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

server/src/wled_controller/static/app.js

@@ -164,8 +164,8 @@ document.addEventListener('DOMContentLoaded', async () => {
     // Show content now that translations are loaded
     document.body.style.visibility = 'visible';
 
-    // Restore collapsible section states
-    initCollapsibleSections();
+    // Restore active tab
+    initTabs();
 
     // Load API key from localStorage
     apiKey = localStorage.getItem('wled_api_key');
@@ -298,7 +298,8 @@ async function loadDisplays() {
             return;
         }
 
-        // Render visual layout
+        // Cache and render visual layout
+        _cachedDisplays = data.displays;
         renderDisplayLayout(data.displays);
     } catch (error) {
         console.error('Failed to load displays:', error);
@@ -309,25 +310,22 @@ async function loadDisplays() {
     }
 }
 
-function toggleSection(name) {
-    const header = document.querySelector(`.collapsible-header[data-section="${name}"]`);
-    const content = document.getElementById(`${name}-content`);
-    if (!header || !content) return;
-    const collapsed = !header.classList.contains('collapsed');
-    header.classList.toggle('collapsed', collapsed);
-    content.classList.toggle('collapsed', collapsed);
-    localStorage.setItem(`section_${name}_collapsed`, collapsed ? '1' : '0');
+let _cachedDisplays = null;
+
+function switchTab(name) {
+    document.querySelectorAll('.tab-btn').forEach(btn => btn.classList.toggle('active', btn.dataset.tab === name));
+    document.querySelectorAll('.tab-panel').forEach(panel => panel.classList.toggle('active', panel.id === `tab-${name}`));
+    localStorage.setItem('activeTab', name);
+    if (name === 'displays' && _cachedDisplays) {
+        requestAnimationFrame(() => renderDisplayLayout(_cachedDisplays));
+    }
 }
 
-function initCollapsibleSections() {
-    document.querySelectorAll('.collapsible-header[data-section]').forEach(header => {
-        const name = header.getAttribute('data-section');
-        const content = document.getElementById(`${name}-content`);
-        if (localStorage.getItem(`section_${name}_collapsed`) === '1' && content) {
-            header.classList.add('collapsed');
-            content.classList.add('collapsed');
-        }
-    });
+function initTabs() {
+    const saved = localStorage.getItem('activeTab');
+    if (saved && document.getElementById(`tab-${saved}`)) {
+        switchTab(saved);
+    }
 }
 
 function renderDisplayLayout(displays) {
@@ -409,7 +407,10 @@ async function loadDevices() {
         const container = document.getElementById('devices-list');
 
         if (!devices || devices.length === 0) {
-            container.innerHTML = `<div class="loading">${t('devices.none')}</div>`;
+            container.innerHTML = `<div class="card add-device-card" onclick="showAddDevice()">
+                <div class="add-device-icon">+</div>
+                <div class="add-device-label">${t('devices.add')}</div>
+            </div>`;
             return;
         }
 
@@ -473,7 +474,11 @@ async function loadDevices() {
             })
         );
 
-        container.innerHTML = devicesWithState.map(device => createDeviceCard(device)).join('');
+        container.innerHTML = devicesWithState.map(device => createDeviceCard(device)).join('')
+            + `<div class="card add-device-card" onclick="showAddDevice()">
+                   <div class="add-device-icon">+</div>
+                   <div class="add-device-label">${t('devices.add')}</div>
+               </div>`;
 
         // Update footer WLED Web UI link with first device's URL
         const webuiLink = document.querySelector('.wled-webui-link');

server/src/wled_controller/static/index.html

@@ -32,12 +32,13 @@
             </div>
         </header>
 
-        <section class="devices-section">
-            <div class="section-header">
-                <h2 class="collapsible-header" onclick="toggleSection('devices')" data-section="devices"><span data-i18n="devices.title">💡 Devices</span><span class="collapse-chevron">▼</span></h2>
-                <button class="btn btn-icon btn-primary" onclick="showAddDevice()" data-i18n-title="devices.add" title="Add New Device">+</button>
+        <div class="tabs">
+            <div class="tab-bar">
+                <button class="tab-btn active" data-tab="devices" onclick="switchTab('devices')"><span data-i18n="devices.title">💡 Devices</span></button>
+                <button class="tab-btn" data-tab="displays" onclick="switchTab('displays')"><span data-i18n="displays.layout">🖥️ Displays</span></button>
             </div>
-            <div id="devices-content" class="collapsible-content">
+
+            <div class="tab-panel active" id="tab-devices">
                 <p class="section-tip">
                     <strong><span data-i18n="devices.wled_config">WLED Configuration:</span></strong> <span data-i18n="devices.wled_note">Configure your WLED device (effects, segments, color order, power limits, etc.) using the</span>
                     <a href="https://kno.wled.ge/" target="_blank" rel="noopener" data-i18n="devices.wled_link">official WLED app</a>
@@ -50,11 +51,8 @@
                     <div class="loading" data-i18n="devices.loading">Loading devices...</div>
                 </div>
             </div>
-        </section>
 
-        <section class="displays-section">
-            <h2 class="collapsible-header" onclick="toggleSection('displays')" data-section="displays"><span data-i18n="displays.layout">🖥️ Displays</span><span class="collapse-chevron">▼</span></h2>
-            <div id="displays-content" class="collapsible-content">
+            <div class="tab-panel" id="tab-displays">
                 <div class="display-layout-preview">
                     <div id="display-layout-canvas" class="display-layout-canvas">
                         <div class="loading" data-i18n="displays.loading">Loading layout...</div>
@@ -62,7 +60,7 @@
                 </div>
                 <div id="displays-list" style="display: none;"></div>
             </div>
-        </section>
+        </div>
 
         <footer class="app-footer">
             <div class="footer-content">

server/src/wled_controller/static/style.css

@@ -168,6 +168,41 @@ section {
     grid-column: 1 / -1;
 }
 
+.add-device-card {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    cursor: pointer;
+    border: 2px dashed var(--border-color);
+    background: transparent;
+    min-height: 160px;
+    transition: border-color 0.2s, background 0.2s;
+}
+
+.add-device-card:hover {
+    border-color: var(--primary-color);
+    background: rgba(33, 150, 243, 0.05);
+}
+
+.add-device-icon {
+    font-size: 2.5rem;
+    font-weight: 300;
+    color: var(--text-secondary);
+    line-height: 1;
+    transition: color 0.2s;
+}
+
+.add-device-card:hover .add-device-icon {
+    color: var(--primary-color);
+}
+
+.add-device-label {
+    font-size: 0.85rem;
+    color: var(--text-secondary);
+    margin-top: 8px;
+}
+
 .card {
     background: var(--card-bg);
     border: 1px solid var(--border-color);
@@ -374,40 +409,43 @@ section {
     font-size: 1.2rem;
 }
 
-/* Collapsible sections */
-.collapsible-header {
+/* Tabs */
+.tab-bar {
+    display: flex;
+    align-items: center;
+    gap: 4px;
+    border-bottom: 2px solid var(--border-color);
+    margin-bottom: 16px;
+}
+
+.tab-btn {
+    background: none;
+    border: none;
+    padding: 10px 18px;
+    font-size: 1rem;
+    font-weight: 500;
+    color: var(--text-secondary);
     cursor: pointer;
-    user-select: none;
+    border-bottom: 2px solid transparent;
+    margin-bottom: -2px;
+    transition: color 0.2s, border-color 0.2s;
 }
 
-.collapsible-header:hover {
-    opacity: 0.8;
+.tab-btn:hover {
+    color: var(--text-color);
 }
 
-.collapsible-header .collapse-chevron {
-    display: inline-block;
-    font-size: 0.6em;
-    margin-left: 6px;
-    transition: transform 0.2s ease;
-    vertical-align: middle;
+.tab-btn.active {
+    color: var(--primary-color);
+    border-bottom-color: var(--primary-color);
 }
 
-.collapsible-header.collapsed .collapse-chevron {
-    transform: rotate(-90deg);
+.tab-panel {
+    display: none;
 }
 
-.collapsible-content {
-    overflow: hidden;
-    transition: max-height 0.3s ease, opacity 0.2s ease;
-    max-height: 2000px;
-    opacity: 1;
-}
-
-.collapsible-content.collapsed {
-    max-height: 0;
-    opacity: 0;
-    margin: 0;
-    padding: 0;
+.tab-panel.active {
+    display: block;
 }
 
 /* Display Layout Visualization */