How to change font size?

I feel the font size of my articles are too small.And it is hard to read.I want make it bigger.But I don’t know because I’m not familiar with the code.Anyone help me? This is the code of my style.css

/*
Theme Name: LightWord
Theme URI: https://www.lightword-theme.com
Description: Simply clever theme with two columns, right-sidebar, fixed-width, widget-ready and threaded comments. Compatible with WordPress 2.8, valid XHTML & CSS. Stay updated!
Author: Andrei Luca
Template: lightword
Version: 1.9.3
Tags: white, light, two-columns, right-sidebar, fixed-width, theme-options, translation-ready, threaded-comments, custom-header
.
Released under the GPL.
.
*/

/* RESET */
html,body,div,span,applet,object,iframe,h1,h2,h3,h4,h5,h6,p,blockquote,pre,a,abbr,acronym,address,big,cite,code,del,dfn,em,font,img,ins,kbd,q,s,samp,small,strike,strong,sub,sup,tt,var,dl,dt,dd,ol,ul,li,fieldset,form,label,legend,table,caption,tbody,tfoot,thead,tr,th,td{border:0;outline:0;vertical-align:baseline;background:transparent;margin:0;padding:0;}

/* BASIC */
*:focus{outline:none;}
.clear{clear:both;}
body{background-color:#2C2C29;font-family:Tahoma;font-size:11px;color:#2C2C29;}
p{font-size:1.2em;padding:2px;margin:1px 0 15px;}
a{color:#807D7A;}
h2{background-color:#FFF;border-bottom:1px solid #DCDCDB;letter-spacing:-1px;font-size:24px;padding-bottom:3px;font-weight:400;margin:10px 0 3px 0;font-family:Helvetica, Georgia;}
h2 a{font-weight:700;border:0;text-decoration:none;color:#2C2C29;display:block;}
h3{font-size:1.8em;}
h4{font-size:1.5em;}
h5{font-size:1.4em;}
h6{font-size:1.3em;}
img,img a{border:1px solid #EEE;padding:2px;margin-left:-2px;}
hr{color:#DCDCDB;background-color:#DCDCDB;height:1px;border:0px;}
pre{width:100%; white-space:pre-wrap;}

/* LAYOUT */
#wrapper{margin:0 auto;text-align:left;}
h1#logo,h1#logo a{font-family:Helvetica,Georgia;padding:0;margin-top:7px;font-size:36px;color:#FFF;text-decoration:none;text-transform:uppercase;}
h1#logo small{color:#FFF;font-size:12px;display:block;margin:-7px 2px 1px;height:20px;}
h1#logo small a{font-size:12px;border-bottom:1px solid #FFF;}
#rss-feed{float:right;width:190px;font-weight:700;position:relative;top:35px;left:7px;color:#FFF;text-decoration:none;}
#header{height:113px;}
#top{cursor:pointer;display:block;margin-left:5px;position:relative;bottom:-55px;margin-top:-55px;min-height:56px;}
#top strong{display:none;}
#top_bar{padding:72px 23px 0 20px;}
#searchform{float:right;width:191px;height:26px;background:url(images/searchbox.png) no-repeat;position:relative;top:1px;}
#header #s{border:1px solid #000;float:left;border:0;width:154px;background:none;color:#ACACAB;margin:4px 0 0 4px;}
#header #go{float:right;width:25px;height:26px;background-color:transparent;border:0px;cursor:pointer;}
#content{padding:0 10px 15px 15px;margin-left:7px;}
#content-body{display:inline-block;min-height:300px;height:auto !important;margin-right:25px;}
* html #content-body{float:left;margin-right:24px;} *+html #content-body{float:left;margin-right:28px;}
#footer{height:8px;}
#footer .text{color:#8D837B;font-size:10px;display:block;padding:12px;}
#footer .top{position:relative;right:5px;top:-5px;display:inline;float:right;}
* html #footer .top{top:-20px;} *+html #footer .top{top:-20px;}
#footer em, #footer em a{font-style:normal;color:#41413E;}

/* FRONT MENU */

ul#front_menu{float:left;text-transform:uppercase;position:relative;top:-4px;}
* html .expand{margin-top:-13px;} *+html .expand{margin-top:-13px;}
#front_menu li{list-style:none;float:left;margin-right:4px;}
* html #front_menu li{height:36px;display:inline;}
#front_menu li a{height:36px;display:block;background:url(images/nav.png) no-repeat left top;padding-left:15px;color:#2C2C29;font:700 .88em/26px Arial, Helvetica, sans-serif;text-decoration:none;cursor:pointer;}
#front_menu li a span{height:36px;display:block;background:url(images/nav.png) no-repeat right top;line-height:36px;padding-right:15px;}
#front_menu li a:hover,#front_menu li a.s{background-position:left bottom;}
#front_menu li a:hover span,#front_menu li a.s span{background-position:right bottom;}
* html #front_menu li a,* html #front_menu li a span{width:1%;white-space:nowrap;cursor:pointer;}
* html #front_menu li a span{position:relative;}
#front_menu ul {position:relative;z-index:3;}
#front_menu li {background:none;float:left; position:relative;}
#front_menu ul {width:200px;position:absolute;display:none; background:#FFF;border-left:1px solid #ACACAB;border-right:1px solid #ACACAB;border-bottom:1px solid #ACACAB;}
#front_menu ul li a, #front_menu ul li a span{margin:-3px -1px;height:auto;background:none;}
#front_menu li ul a {width:200px; float:left; white-space:nowrap;}
#front_menu ul ul {top:auto;}
#front_menu li ul ul {left:1em; }
#front_menu li:hover ul ul, #front_menu li:hover ul ul ul, #front_menu li:hover ul ul ul ul {display:none;}

/* WP */
blockquote{margin:20px 10px 10px 5px;border-left:4px solid #DDD;padding:0 5px 0 5px;font-size:9px;text-align:justify;}
.commenttext blockquote{border-left:4px solid #B6B6B5;}
.wp-caption{border:1px solid #ddd;text-align:center;background-color:#f3f3f3;padding-top:4px;}
.wp-caption img{border:none;margin:0;padding:0;}
.wp-caption p.wp-caption-text{font-size:11px;line-height:17px;color:#111;margin:0;padding:0 4px 5px;}
.alignleft,img.alignleft{float:left;margin:5px 10px 5px 0;}
.alignright,img.alignright{float:right;margin:5px 0 5px 10px;}
.aligncenter,div.aligncenter,img.aligncenter{text-align:center;display:block;margin:10px auto;}
abbr, acronym, span.abbr{cursor:help;border-bottom:1px dotted #000;}
#content-body table { border-collapse:collapse; width:100%; border:0; }
#content-body table { margin:0 0 1em 1px; }
#content-body td, .post th { border:1px solid #DCDCDB; padding:10px; }
#content-body th { background:#EEE; font:18px normal; }
.wp_syntax { width:auto; }
.wp_syntax table { border:0 !important; }
.wp_syntax table td { border:0 !important; }
img.wp-smiley{border:0px;vertical-align:middle;}

/* CONTENT */
#content-body ul,#content-body ol{margin:15px 30px;font-size:12px;}
#content-body ul li{list-style:circle;margin-bottom:4px;}
.hentry{min-height:150px;height:auto!important;margin-bottom:1em;}
.sticky h2 a{color:red;}
.comm_date{background:transparent url(images/date_comm_box.png) no-repeat;height:100px;width:57px;position:absolute;text-align:center;margin:0 0 0 -72px;z-index:2;}
.only_date{background:transparent url(images/data_box.png) no-repeat !important;height:67px !important;}
* html .comm_date{margin-top:10px;} *+html .comm_date{margin-top:10px;}
.comm_date .data{margin-left:-1px;padding-top:10px;display:block;font-weight:700;text-transform:uppercase;letter-spacing:-1px;}
.comm_date .nr_comm{padding-top:14px;color:#FFF;display:block;font-weight:700;}
.comm_date .nr_comm_spot, .comm_date .dsq-comment-count{display:block;margin:0 9px 0 8px;padding:6px 0 5px 0;}
.comm_date .data .j{font-size:24px;display:block;}
.nr_comm a{color:#FFF;text-decoration:none;}
.cat_tags{margin-top:10px;padding:8px 0 5px 10px;}
.cat_tags_close{max-height:3px;height:3px;margin-bottom:20px;}
* html .cat_tags_close{margin-top:-8px;}
*:first-child+html .cat_tags{padding:9px 8px 0;margin-bottom:-3px;}
.cat_tags .continue{float:right;padding-right:10px;width:100px;text-align:center;}
.cat_tags .category{float:left;}
.cat_tags a,.cat_tags .continue a{color:#2C2C29;}
.cat_tags a:hover{color:#ACACAB;}

/* SIDEBAR */
.content-sidebar{width:191px;display:inline-block;overflow:hidden;vertical-align:top;}
.content-sidebar input{padding:3px;border:1px solid #E5E2E0;margin-bottom:2px;}
.content-sidebar h3{margin-top:8px;display:block;background:#FFF url(images/sidebar_h3.png) no-repeat;height:22px;width:181px;font-weight:700;font-size:11px;padding:9px 0 0 10px;}
.content-sidebar h3 a{text-decoration:none;color:#2C2C29;line-height:13px;}
.content-sidebar ul{list-style:none;width:191px;padding:2px;}
.content-sidebar li{list-style:none;}
* html .content-sidebar ul{width:160px;}
.content-sidebar ul li{display:block;color:#9D9793;line-height:16px;padding:4px 0 4px;border-bottom:1px solid #EEE;width:185px;}
.content-sidebar ul ul li{border:0px;padding-bottom:0;width:140px;}
.content-sidebar ul li.page_item ul li.page_item , .content-sidebar ul li.cat-item ul.children li.cat-item{background:url(images/arrow.gif) 0 11px no-repeat;padding-left:11px;margin-top:-3px;}
.content-sidebar ul li.page_item ul li.page_item ul li.page_item, .content-sidebar ul li.cat-item ul.children li.cat-item ul.children li.cat-item{background:url(images/arrow.gif) 0 11px no-repeat;padding-left:12px;}
.content-sidebar ul li a:hover,.content-sidebar .recentcomments a:hover{color:#AAA;}
.content-sidebar .textwidget, .content-sidebar select{padding:3px;margin:10px 2px 10px 2px;width:188px;}
.content-sidebar .recentcomments{display:block;border-bottom:1px solid #EEE;color:#9D9793;padding:4px 0px;line-height:16px;}
.content-sidebar .right {float:right; width:91px;overflow:hidden;}
.content-sidebar .left {float:left; width:91px;overflow:hidden;}

/* COMMENTS */
#content-body input{padding:3px;border:1px solid #E5E2E0;margin-bottom:2px;}
#content-body textarea{border:1px solid #E5E2E0;width:98.6%;height:100px;padding:5px;font: 12px Verdana;}
#content-body input#submit {width: 88px;height: 25px;border: 0px;background:#2C2C29 url(images/submit_btn.png) no-repeat;font: bold 12px Helvetica,Georgia,serif;color:#FFF;text-align:center;cursor:pointer;}
#comentarii ol.commentlist{width:100%;margin:0;padding:0;font-size:11px;}
ol.commentlist{list-style:none;}
ol.commentlist li{list-style-type:none;margin-bottom: 10px;background-color: #F5F5F5;border: 1px solid #DDD;padding: 15px 10px 4px 10px;}
ol.commentlist li ul{list-style-type: none;margin-left: 7px !important;}
ol.commentlist li ul.children li{list-style:none !important;background-color: #FFF;width:100%;font-size:11px;}
ol.commentlist li ul.children li ul.children li{background-color:#F5F5F5;}
ol.commentlist li div.comment_content{float: left;width: 100%;}
ol li div.comment_content div.commentmetadata{color: #999;border-bottom: 1px solid #ddd;margin:0px 8px 5px;}
ol li div.comment_content div.commentmetadata a{color: #bbb;text-decoration: none;}
ol li div.comment_content p{padding:0 0 16px 6px;}
ol li div.comment_content .reply{margin:8px;}
strong.comment_author{font-size:125%;}
strong.comment_author a{text-decoration:underline !important;}
a#cancel-comment-reply-link{text-transform:uppercase;font-size:80%;margin-left:10px;}
li #respond{padding:7px;}
li #respond h2{display:none;}
li.comment-author-admin{border:1px solid #BBBBBB !important; }

/* COMMENTS / TRACKBACKS TABS */
#tabsContainer p{margin-bottom:-2px !important;}
#tabsContainer{margin-top:2em;}
#tabsContainer a{text-decoration:none;}
.trackbacks{background-color:#EEEEEE;margin-bottom:5px;padding:10px;border-bottom:1px solid #CCC;}
.tab-content {background-color:#FFF;display: none;}
.tab-content p.no{padding-top:10px;}
.tab-content.selected { display: block; }
.clear_tab{clear:both;border-bottom:3px solid #2C2C29;margin-top:-21px;}
.tabs {display: block;float: left;height: 30px;padding: 0 0 0 20px;line-height: 29px;position: relative;top: 1px;color: #787878;text-decoration: none;margin: 0 0px 0 0;}
.subscribe_comments {display: block;float: right;height: 30px;padding: 0 0 0 20px;line-height: 29px;position: relative;top: 1px;color: #787878;text-decoration: none;margin: 0 5px 0 0;}
.tabs span {display: block;float: left;padding: 0 20px 0 0;cursor:pointer;}
.tabs.selected {background-color:#2C2C29;color:#FFF; }
div.selected{background-color:#FFF;color:#2C2C29;}

/* PAGINATION */
.nav_link{margin-top:15px;border-top:1px solid #DDD;background-color:#F5F5F5;padding:10px;}
.nav_link a{text-decoration:none;}
.nav_link .page_number{border:1px solid #DDD;padding:2px 10px;background-color:#EDEDED;}
.nav_link a .page_number{border:1px solid #DDD;background-color:#F5F5F5;padding:2px 10px;}
.newer_older a{margin-top:1em;text-decoration:none;font-size:12px;letter-spacing:-1px;font-weight:700;}
.newer a{background:#FFF url(images/older_newer.png) no-repeat;width:129px;padding:6px 3px 6px 0px;float:left;cursor:pointer;text-align:center;height:14px;}
.older a{background:#FFF url(images/older_newer.png) no-repeat;width:129px;padding:6px 3px 6px 2px;float:right;cursor:pointer;text-align:center;height:14px;}
.next_previous_links{margin-top:10px;border-top:1px solid #DDD;background-color:#F5F5F5;padding:0 5px;}
.next_previous_links_comments{margin-top:10px;border-bottom:1px solid #DDD;background-color:#F5F5F5;padding:0 5px;}

/* WIDGETS */
#wp-calendar {font-size: 1.2em;empty-cells: show;line-height:5px;margin-top:10px;margin-left:-5px;}
#wp-calendar a {font-size: 1.0em;display: block;font-weight: bold;}
#wp-calendar #next a {padding-right: 10px;text-align: right;}
#wp-calendar #prev a {padding-left: 10px;text-align: left;}
#wp-calendar caption {padding:2px 0;margin: 8px 0;text-transform: uppercase;letter-spacing: 0.3em;font-weight: lighter;font-size: .8em;color: #444;text-align: right;}
#wp-calendar th {padding: 4px 5px 4px 6px;font-weight: lighter;font-size: .8em;color: #666;text-align: right;background: #f4f4f4;}
#wp-calendar td {padding: 4px 5px 4px 6px;text-align: right;}
#wp-calendar td#today {background: #e0e0e0;}
#wp-calendar td#prev a {padding: 0;text-align: left;font-weight: normal;}
#wp-calendar td#next a {padding: 0;text-align: right;font-weight: normal;}
a.rsswidget img{display:none;}
div.rssSummary{margin:5px;}

/* ARCHIVE */
.archive_h2{text-transform:uppercase;cursor:pointer;font-size:16px;}
.archive_h2 span{font-size:12px;}
ul.hide{list-style-type:none;display:none;}

/* OTHERS */
.promote{border:1px solid #B6B6B5;padding:10px 10px 5px 10px;margin-top:1em;background:#EDEDED url(images/rss.png) 90% -35px no-repeat;}
.promote h3{margin-left:3px; }
.post-edit-link{display:block;background-color:#F5F5F5;margin-bottom:1em;padding:5px;color:#B6B6B5;}
.post-edit-link:hover{background-color:#FFFFD3;color:#2C2C29;}
.comment-edit-link{background-color:#EFEFEF;padding:1px 5px;color:#999999;border-left:1px solid #DDD;}
.about_author{border-top:1px solid #DDD;background-color:#F5F5F5;padding:10px;margin-top:10px;}
.moderation{font-size:80%;}
#breadcrumbs{background-color:#F5F5F5;padding:5px;}
ol.snap_nav{list-style:none;display:block;}
ol.snap_nav li{display:inline; background-color:#F4F4F4;padding:3px;}
ol.snap_nav .snap_selected{background-color:#DDD;}
.simple_date{background:url(images/date.png) 5px 50% no-repeat;padding:8px 25px;background-color:#EEE;margin-bottom:1em;}

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