Styling overwritten

I have a question about styling on which i have been breaking my head this morning but cant seem to figure out. Why is the styling that i used in the example below overwritten and how can i stop it from being overwritten :] Edit: Thanks to Michel i found that the following solved my problem .tundra .reportingDateRange table th { background-color: white; } But still i wonder should an css selector of equal level not always overrule the tundra css selector?
1 answers

General CSS rules apply here. Overwrite style by either using a more specific selector or using the !important tag.

More specific selector is for example

.tundra table .dateRangeSelector th {
 background-color: white;