Add PDF Survey Importer with smart Thai questionnaire parser and preview editor

css/style.css

@@ -2745,4 +2745,64 @@ table {
     }
 }
 
+/* ============================================================
+   PDF Importer Styles
+   ============================================================ */
+.pdf-drop-zone {
+    border: 2px dashed #94a3b8;
+    border-radius: 12px;
+    padding: 36px 20px;
+    text-align: center;
+    background: #f8fafc;
+    cursor: pointer;
+    transition: all 0.25s ease;
+    user-select: none;
+}
+
+.pdf-drop-zone:hover,
+.pdf-drop-zone.drag-over {
+    border-color: #dc2626;
+    background: #fef2f2;
+    transform: translateY(-2px);
+    box-shadow: 0 4px 12px rgba(220, 38, 38, 0.1);
+}
+
+.pdf-drop-icon {
+    font-size: 42px;
+    margin-bottom: 10px;
+    transition: transform 0.2s ease;
+}
+
+.pdf-drop-zone:hover .pdf-drop-icon {
+    transform: scale(1.15);
+}
+
+.pdf-q-row {
+    transition: all 0.2s ease;
+}
+
+.pdf-q-row:hover {
+    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
+    border-color: #93c5fd !important;
+}
+
+.pdf-preview-container::-webkit-scrollbar {
+    width: 6px;
+}
+
+.pdf-preview-container::-webkit-scrollbar-track {
+    background: #f1f5f9;
+    border-radius: 4px;
+}
+
+.pdf-preview-container::-webkit-scrollbar-thumb {
+    background: #cbd5e1;
+    border-radius: 4px;
+}
+
+.pdf-preview-container::-webkit-scrollbar-thumb:hover {
+    background: #94a3b8;
+}
+
+