Clean form elements and page layout

1. Center the form elements on the **search tab**, i.e. *Select Date Range*, *From:*, *To:*, *Select Keyword(s)*, etc.


2. Remove horizontal scrolling within the **search tab**.


3. Adjust the button sizes and text padding so that text is always centered.


4. Increase the padding between the panels on the page so that the elements don't look crammed. For example, (1) need spacing above the *SEARCH* and *LEGENDS* tabs and (2) need spacing above and below the CUAHSI logo.