update download button

frontend/src/components/BenchmarkCreateForm.jsx

@@ -523,6 +523,13 @@ function BenchmarkCreateForm({ onStartGeneration }) {
                     onClick={() => handleDownloadDocument(modalDocument)}
                     disabled={isDownloading}
                     aria-label="download"
+                    sx={{
+                      color: "text.secondary",
+                      opacity: 0.4,
+                      "&:hover": {
+                        opacity: 0.8,
+                      },
+                    }}
                   >
                     {isDownloading ? (
                       <CircularProgress size={20} />