feat: add custom scrollbar styles for light and dark themes

- Implemented custom scrollbar styles in src/index.css for improved aesthetics.
- Added styles for both light and dark themes, enhancing user experience across different modes.

src/index.css

@@ -118,3 +118,50 @@
     @apply bg-background text-foreground;
   }
 }
+
+/* 自定义滚动条样式 */
+* {
+  scrollbar-width: thin;
+  scrollbar-color: oklch(0.551 0.027 264.364 / 0.3) transparent;
+}
+
+*::-webkit-scrollbar {
+  width: 8px;
+  height: 8px;
+}
+
+*::-webkit-scrollbar-track {
+  background: transparent;
+  border-radius: 4px;
+}
+
+*::-webkit-scrollbar-thumb {
+  background: oklch(0.551 0.027 264.364 / 0.3);
+  border-radius: 4px;
+  transition: background 0.2s ease;
+}
+
+*::-webkit-scrollbar-thumb:hover {
+  background: oklch(0.551 0.027 264.364 / 0.5);
+}
+
+*::-webkit-scrollbar-thumb:active {
+  background: oklch(0.551 0.027 264.364 / 0.6);
+}
+
+/* 深色模式下的滚动条 */
+.dark *::-webkit-scrollbar-thumb {
+  background: oklch(0.707 0.022 261.325 / 0.4);
+}
+
+.dark *::-webkit-scrollbar-thumb:hover {
+  background: oklch(0.707 0.022 261.325 / 0.6);
+}
+
+.dark *::-webkit-scrollbar-thumb:active {
+  background: oklch(0.707 0.022 261.325 / 0.7);
+}
+
+.dark * {
+  scrollbar-color: oklch(0.707 0.022 261.325 / 0.4) transparent;
+}