refactor: Modularize UI components and utilities

- Extract UI components into separate JS files
- Centralize configuration values in config.js
- Introduce a dedicated logger module
- Improve file tree drag-and-drop and undo functionality
- Refactor modal handling to a single manager
- Add URL routing support for SPA navigation
- Implement view mode for read-only access

static/style.css

@@ -33,7 +33,8 @@ body.dark-mode {
 }
 
 /* Global styles */
-html, body {
+html,
+body {
     height: 100%;
     margin: 0;
     padding: 0;
@@ -48,12 +49,6 @@ body {
     transition: background-color 0.3s ease, color 0.3s ease;
 }
 
-.container-fluid {
-    flex: 1;
-    padding: 0;
-    overflow: hidden;
-}
-
 .row {
     margin: 0;
 }
@@ -206,7 +201,12 @@ body.dark-mode .CodeMirror-linenumber {
 }
 
 /* Markdown preview styles */
-#preview h1, #preview h2, #preview h3, #preview h4, #preview h5, #preview h6 {
+#preview h1,
+#preview h2,
+#preview h3,
+#preview h4,
+#preview h5,
+#preview h6 {
     margin-top: 24px;
     margin-bottom: 16px;
     font-weight: 600;
@@ -286,7 +286,8 @@ body.dark-mode .CodeMirror-linenumber {
     margin-bottom: 16px;
 }
 
-#preview ul, #preview ol {
+#preview ul,
+#preview ol {
     margin-bottom: 16px;
     padding-left: 2em;
 }
@@ -378,7 +379,7 @@ body.dark-mode .mermaid svg {
     .sidebar {
         display: none;
     }
-    
+
     .editor-pane,
     .preview-pane {
         height: 50vh;
@@ -590,5 +591,4 @@ body.dark-mode .sidebar h6 {
 
 body.dark-mode .tree-children {
     border-left-color: var(--border-color);
-}
-
+}