Increase paragraph spacing in theme via CSS

I am using the theme elements from wpnow. You can see it http://www.wpnow.com/demo/#elements

And as you can see, (from the theme demo) that the paragraphs are too close together for my tastes. How do i change it so that the paragraphs are more spaced apart. Here is an excerpt from the CSS.

/************************************************************\
* Left
\************************************************************/
.wpn_left {float:left;width:620px;overflow:hidden;}
.wpn_left .wpn_heading:first-child {margin:0 0 2px;}

/* Box */
.wpn_left .wpn_box {padding:19px;background:#222 url(img/news_bg.gif) repeat-x top;position:relative;height:1%;-moz-border-radius-topleft:3px;-moz-border-radius-topright:3px;}
.wpn_left .wpn_box-bottom {background:url(img/box_bottom.gif) repeat-x top;height:10px;-moz-border-radius-bottomleft:3px;-moz-border-radius-bottomright:3px;margin-bottom:15px;clear:both;}

.wpn_fullwidth {width:100%;}

/* Featured Posts */
.wpn_featured img {vertical-align:middle;}

/************************************************************\
* News & Updates / Article Pages / Archive List
\************************************************************/
.wpn_news {list-style:none;}
.wpn_news > li {padding:19px;background:#222 url(img/news_bg.gif) repeat-x top;-moz-border-radius:3px;padding-bottom:56px;position:relative;margin-bottom:15px;height:1%;}

/* Information / Avatar */
.wpn_news .wpn_title {font-size:26px;color:#fff;font-weight:bold;}
.wpn_news .wpn_info {padding:15px 0 15px;border-bottom:1px dotted #4d4d4d;height:40px;line-height:22px;color:#999;margin-bottom:5px;}
.wpn_news .wpn_info img {float:left;background:#222;border:1px solid #5e5e5e;padding:1px;margin-right:8px;width:40px;height:40px;display:block;}
.wpn_news .wpn_info a {color:#ff6eae;}
.wpn_news .wpn_thumb {display:block;width:580px;height:78px;background:#222;border:1px solid #5e5e5e;padding:1px;}

/* Post */
.wpn_news .wpn_post {line-height:18px;padding-top:5px;text-align:left;}
.wpn_news .wpn_post h1, .wpn_news .wpn_post h2, .wpn_news .wpn_post h3, .wpn_news .wpn_post h4, .wpn_news .wpn_post h5, .wpn_news .wpn_post h6 {border-bottom:1px dotted #4d4d4d;margin:5px 0 5px;padding:5px 0 5px;color:#fff;font-family:Arial;}
.wpn_news .wpn_post h1 {border-bottom:3px solid #4d4d4d;font-size:24px;}
.wpn_news .wpn_post h2 {font-size:20px;}
.wpn_news .wpn_post h3 {font-size:16px;}
.wpn_news .wpn_post h4 {font-size:14px;}
.wpn_news .wpn_post h5 {font-size:12px;}
.wpn_news .wpn_post h6 {font-size:10px;}

.wpn_news .wpn_post ul {margin:5px 0 5px;}
.wpn_news .wpn_pust ul ul {margin:0;}
.wpn_news .wpn_post ol {margin:5px 0 5px;}
.wpn_news .wpn_post ol ol {margin:0;}
.wpn_news .wpn_post ul li {list-style-position:inside;margin-left:10px;list-style-image:url(img/list_bullet.gif);}
.wpn_news .wpn_post ol li {list-style-position:inside;list-style-type:decimal-leading-zero;margin-left:10px;}

.wpn_news .wpn_post img {max-width:580px;background:#222;border:1px solid #5e5e5e;padding:1px;}
.wpn_post img.centered{display:block;margin-left:auto;margin-right:auto;}
.wpn_post img.alignright{padding:4px;margin:0 0 2px 7px;display:inline;}
.wpn_post img.alignleft {padding:4px;margin:0 7px 2px 0;display:inline;}
.wpn_post .alignright {float:right;}
.wpn_post.alignleft {float:left }
.aligncenter, div.aligncenter {display:block;margin-left:auto;margin-right:auto;}
.wpn_post .wp-caption {border:1px solid #ddd;text-align:center;background-color:#f3f3f3;padding-top:4px;margin:10px;-moz-border-radius:3px;-khtml-border-radius:3px;-webkit-border-radius:3px;border-radius:3px;}
.wpn_post.wp-caption img {margin:0;padding:0;border:0 none;}
.wpn_post .wp-caption p.wp-caption-text {font-size:11px;line-height:17px;padding:0 4px 5px;margin:0;}

.wpn_news .wpn_post p {padding-bottom:5px;line-height:18px;}
.wpn_news .wpn_post a {color:#ff6eae;font-weight:bold;}

.wpn_news .wpn_post blockquote {margin:10px;background:#303030;padding:10px;border:1px solid #414141;position:relative;border-left:10px solid #808f36;}
.wpn_news .wpn_post blockquote blockquote {background:#222;border-left:10px solid #398a89;}