diff --git a/app/assets/stylesheets/problems.css.scss b/app/assets/stylesheets/problems.css.scss
--- a/app/assets/stylesheets/problems.css.scss
+++ b/app/assets/stylesheets/problems.css.scss
@@ -0,0 +1,15 @@
+tr {
+  &.available {
+    background: #c0ffc0;
+  }
+
+  &.not-available {
+    background: #ffc0c0;
+  }
+}
+
+.import-log {
+  background: lightgray;
+  border: solid black 1px;
+  padding: 10px;
+}