feat(chat): 聊天滚动条美化 + Markdown 增强 — OverlayScrollbars/CodeHighlighter/代码复制/表格样式

src/web/styles.css

@@ -124,22 +124,13 @@ body {
   margin-top: 8px;
 }
 
-.message-body pre {
-  background: var(--ant-color-bg-layout);
-  padding: 8px 12px;
-  border-radius: 6px;
-  overflow-x: auto;
-  font-size: 13px;
-}
-
 .chat-scroll-area {
   flex: 1;
   min-height: 0;
-  overflow: auto;
   overflow-anchor: auto;
   margin-left: var(--ant-padding-sm);
   border-radius: var(--ant-border-radius-lg);
-  scroll-behavior: smooth;
+  height: 100%;
 }
 
 .chat-loading-indicator {
@@ -219,3 +210,38 @@ body {
 .app-page-flex {
   flex: 1;
 }
+
+.os-theme-custom {
+  --os-size: 8px;
+  --os-padding-perpendicular: 2px;
+  --os-padding-axis: 2px;
+  --os-track-border-radius: 10px;
+  --os-handle-border-radius: 10px;
+  --os-handle-bg: rgba(0, 0, 0, 0.15);
+  --os-handle-bg-hover: rgba(0, 0, 0, 0.25);
+  --os-handle-bg-active: rgba(0, 0, 0, 0.35);
+  --os-handle-min-size: 33px;
+  --os-handle-max-size: none;
+  --os-handle-interactive-area-offset: 4px;
+}
+
+.x-markdown-light table {
+  border-collapse: collapse;
+  width: 100%;
+}
+
+.x-markdown-light th,
+.x-markdown-light td {
+  border: 1px solid var(--ant-color-border);
+  padding: 6px 12px;
+  text-align: left;
+}
+
+.x-markdown-light th {
+  background: var(--ant-color-fill-quaternary);
+  font-weight: 600;
+}
+
+.x-markdown-light .x-md-table-wrap {
+  overflow-x: auto;
+}