what does Remove unused CSS mean - Joomla! Forum - community, help and support

i having serious speed trouble site , have turned gtmetric see causing site problems. test results here. http://gtmetrix.com/reports/www.in2town.co.uk/p3ljqxaw

it says @ bottom error on 2 occasions.

1 remove unused css
2 use efficient css selectors

now have looked @ these , says first one.

invalid 'instanceof' operand window.storagelist
removing or deferring style rules not used document avoid downloads unnecessary bytes , allow browser start rendering sooner.

the second 1 says

use efficient css selectors
avoiding inefficient key selectors match large numbers of elements can speed page rendering.

can please me solve these errors

unused css:
css you've written isn't used anywhere. type:

code: select all

<style>
.someselector {
      padding:20px;
      color:red;
}
</style>


but 'class="selector"' found...

inefficient css selectors selectors cover way elements.
for instance, never use '*'

code: select all

* {
    color:black;
    font-family:'arial';
}


the systeem needs check elements implement statement. quite unnecesary!