customize theme

Hi, I am using the seabreeze theme. The post on the blog are very close together. I have done some reading and was able to add a HR line, but is there anyway to add a solid block around the post title and the posting time information? Basically to have the HR line extend down to below the posting time to make the start of each posting stand out more? Here’s my CSS code. By the way I am very new to this

/*
Theme Name: seabreeze
Theme URI: http://freethemelayouts.com/
Description: Designed by <a href="http://freethemelayouts.com">FTL</a>.<br /> This work is licensed <a href="http://creativecommons.org/licenses/by-sa/3.0/">Creative Commons Attribution-Share Alike 3.0 License.</a> This means you may use it and make any changes you like. However, credit links must remain on footer for legal use.
Version: 1
Author: FreeThemeLayout/DreamTemplate
Author URI: http://www.freethemelayouts.com/
*/

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