MAGETWO-59431: Sample Data does not scale correctly when resize window as mobile view

- Fix homepage layout

Author: Nikita Chubukov

app/design/frontend/Magento/blank/web/css/source/_layout.less

@@ -18,7 +18,7 @@
         .column.main {
             &:extend(.abs-add-box-sizing all);
             .lib-css(padding-bottom, @indent__xl);
-            .lib-vendor-prefix-flex-basis(100%);
+            .lib-vendor-prefix-flex-basis(auto);
             .lib-vendor-prefix-flex-grow(1);
             .lib-vendor-prefix-order(1);
             width: 100%;