Tweak styles of header and history (#487)

components/custom/icons.tsx

@@ -762,3 +762,18 @@ export const CopyIcon = ({ size = 16 }: { size?: number }) => (
     ></path>
   </svg>
 );
+
+export const ChevronDownIcon = ({ size = 16 }: { size?: number }) => (
+  <svg
+    height={size}
+    strokeLinejoin="round"
+    viewBox="0 0 16 16"
+    width={size}
+    style={{ color: 'currentcolor' }}
+  >
+    <path
+      d="M12.0607 6.74999L11.5303 7.28032L8.7071 10.1035C8.31657 10.4941 7.68341 10.4941 7.29288 10.1035L4.46966 7.28032L3.93933 6.74999L4.99999 5.68933L5.53032 6.21966L7.99999 8.68933L10.4697 6.21966L11 5.68933L12.0607 6.74999Z"
+      fill="currentColor"
+    ></path>
+  </svg>
+);