misc: 500px 모드를 일관되게 적용.

- media-1000px, media-500px 추가

hwe/scss/util.scss

@@ -0,0 +1,14 @@
+
+
+.s-border-t {
+    border-top: gray solid 1px;
+}
+
+.s-border-b {
+    border-bottom: gray solid 1px;
+}
+
+.s-border-tb {
+    border-top: gray solid 1px;
+    border-bottom: gray solid 1px;
+}