Make site full width in browsers?

I want to make my website full width in all browsers with no issues, how in CSS can i make this happen, i am not that good at CSS so any helkp would be greatly appreciated~

/*
Theme Name: HellFire
Theme URI: https://smthemes.com/hellfire/
Author: The Smart Magazine Themes
Author URI: https://smthemes.com/
Description: Template by SMThemes.com
Version: 2.0
License: Creative Commons 3.0
Theme date: 01/28/2013
License URI: license.txt
Tags: white, red, light, fixed-width, featured-images, custom-menu, translation-ready, threaded-comments, theme-options
*/

/* -==========================- GENERAL -==========================- */
/*—————————— PAGE ——————————*/
@import url(css/fonts.css);
@import url(https://fonts.googleapis.com/css?family=Oswald);
html {
background:#0e0706;
}
body {
background:url(images/background.png) 50% top repeat-x;
color:#181818;
}
a {
color:#a51005;
}
h1, h2, h3, h4, h5, h6, a.post_ttl {
color:#200a03;
text-decoration:none;
}

/*—————————— HEADER ——————————*/
#header {
background:url(images/top.jpg) 50% top no-repeat;
}
#secondarymenu-container {
position:relative;
}

/*—————————— SEARCH ——————————*/
#s {
background:#fff;
border:1px solid #48362f;
border-radius:3px;
-moz-border-radius:3px;
-webkit-border-radius:3px;
box-shadow:0 1px 2px #000 inset;
height:25px;
line-height:25px;
color:#7e7673;
}
.searchbtn {
width:44px;
height:46px;
margin-top:-16px;
}

/*—————————— CONTENT ——————————*/
#content p { font-family: Arial, Calibri, Tahoma; font-size:1.2em;padding:2px;margin:1px 0 15px; }

.articles dt {
border-top:1px dotted #796f66;
padding:0;
margin:0 30px;
margin-top:-1px;
padding-top:1px;

}
.articles dt:first-child {

}
.articles dd {

}
#content .widget h3 {
font-size:18px;
color:#800000;
}

.featured_image {
padding:4px;
background:#fff;
box-shadow:0 1px 3px #8d8d8d;
border:none;
}
.widget_posts ul li img,.widget_flickr a {
background:#fff;
border:none;
box-shadow:0 1px 3px #000;
padding:3px;
margin-bottom:5px;
}
#commentform #submit, input.readmore, a.readmore {
background:url(images/readmore.png) left top no-repeat;
border:none;
width:142px;
height:39px;
line-height:39px;
padding:0;
color:#fff;
text-shadow:0 0 2px #91371a;
}
.page-numbers {
padding:5px 10px;
}
a.page-numbers {
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
color:#2f0900;
box-shadow:0 0 2px #cdcac0 inset;
border:1px solid #beb69f;
}
span.page-numbers {
color:#fff;
border:1px solid #8f594f;
background:#3e0905;
-webkit-border-radius:5px;
-moz-border-radius:5px;
border-radius:5px;
text-decoration:none;
cursor:pointer;
}
/*—————————— FOOTER ——————————*/
#footer {
color:#dedede;
background-image: linear-gradient(bottom, rgb(13,0,4) 0%, rgb(64,14,0) 100%);
background-image: -o-linear-gradient(bottom, rgb(13,0,4) 0%, rgb(64,14,0) 100%);
background-image: -moz-linear-gradient(bottom, rgb(13,0,4) 0%, rgb(64,14,0) 100%);
background-image: -webkit-linear-gradient(bottom, rgb(13,0,4) 0%, rgb(64,14,0) 100%);
background-image: -ms-linear-gradient(bottom, rgb(13,0,4) 0%, rgb(64,14,0) 100%);
background-image: -webkit-gradient( linear, left bottom, left top, color-stop(0, rgb(13,0,4)), color-stop(1, rgb(64,14,0)));
border-top:1px solid #60261b;
margin-top:20px;
}
#footer a {
color:#fff;
}
#footer h3 {
color:#fff;
}
#footer .footer_txt {
border-top:1px dashed #575757;
}

/*—————————— WIDGETS ——————————*/
.tabs_captions .caption {
border-color:#fff;
}
.fp-next, .fp-prev {
margin-top:-52px;
width:41px;
height:105px;
}

/* -==========================- DESKTOP -==========================- */
@media only screen and (min-width:1024px) {

#content-top {
height:43px;
width:1002px;
}
#content-bottom {
height:43px;
width:1002px;
}
#content .container{
width:998px;
padding:0 2px;
background-position:50% !important;
}
#logo {
width:298px;
position:absolute;
left:50%;
margin-left:-150px;
}
.menusearch {
float:right;
margin-top:45px;
}
/*—————————— MENU ——————————*/
#secondarymenu-container {
height:122px;
position:relative;
}
#secondarymenu {
float:left;
background:url(images/topmenu.png) left top repeat-x;
margin-top:55px;
box-shadow:0 0 2px #000;
}
#secondarymenu ul {
margin:0 10px;
}
#secondarymenu li {
}
#secondarymenu li:first-child {
border-left:none;
}
#secondarymenu li:last-child {
border-right:none;
}
#secondarymenu a {
color:#fff;
text-decoration:none;
padding:8px 10px;
display:block;
}
#mainmenu-container {
background:url(images/menu.png) left top no-repeat;
height:42px;
width:1000px;
padding:20px 9px;
margin:0 -9px;
}
#mainmenu li {
}
#mainmenu li a {
color:#fff;
padding:16px 24px;
display:block;
text-decoration:none;
font-family:’charlb’;
}
#mainmenu li a:hover {
background:url(images/hoverli.png) 50% bottom no-repeat;
}
#header li ul {
top:39px;
}
#mainmenu li ul {
top:45px;
left:0%;
}

#header li ul .transparent {
background:#a1322a;
-moz-opacity: 0.23;
opacity: 0.23;
-ms-filter:”progid:DXImageTransform.Microsoft.Alpha”(Opacity=23);

}
#header li ul .inner {
background:#440a05;
margin:1px;
}
#header ul.children li a, .sub-menu li a {
color:#fff !important;
padding:0 !important;
}

/*—————————— SLIDER ——————————*/
.slider-container {
background:url(images/slider.png) left top repeat-y;
position:relative;
padding-bottom:35px;
margin-bottom:20px;
}
.slider {
position:relative;
width:975px;
margin:0 auto;
}
.fp-prev-next-wrap {

}
.fp-next, .fp-prev {
margin:0 10px;
margin-top:-13px;
}
.fp-slides,.fp-thumbnail,.fp-slides-items {
height:408px;
width:975px;
}
.slider-nothumb .fp-content-fon {
background:#fff;
}
.slider-nothumb .fp-content a,.slider-nothumb .fp-content p{
color:#000;
}
.fp-nav {

}

}

/* -==========================- TABLET -==========================- */
@media only screen and (min-width:640px) and (max-width:1023px) {
#logo {
float:left;
}
/*—————————— MENU ——————————*/
.menusearch {
float:right;
margin-top:25px;
margin-right:10px;
}
#secondarymenu-container {
height:102px;
}
#secondarymenu {
float:right;
clear:right;
}
#secondarymenu li {
padding:18px;
}
#secondarymenu li a{
color:#e9e9e9;
text-decoration:none;
}
#mainmenu-container {
clear:left;
background: #3e0905; /* Old browsers */
background: -moz-linear-gradient(top, #3e0905 0%, #2f0704 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#3e0905), color-stop(100%,#2f0704)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, #3e0905 0%,#2f0704 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, #3e0905 0%,#2f0704 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, #3e0905 0%,#2f0704 100%); /* IE10+ */
background: linear-gradient(to bottom, #3e0905 0%,#2f0704 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr=’#3e0905′, endColorstr=’#2f0704′,GradientType=0 ); /* IE6-9 */
margin-bottom:15px;
padding-bottom:15px;
}
#mainmenu {
margin:0 10px;
}
#mainmenu li {

float:left;
}
#mainmenu a {
color:#fff;
text-decoration:none;
padding:15px 20px 7px;
display:block;
}
.slider-container { padding-bottom:35px;}
}

/* -==========================- MOBILE -==========================- */
@media only screen and (min-width:240px) and (max-width:639px) {
.menusearch {padding:3px 0;}
#secondarymenu-container {
padding:0;

}
#logo {
height:107px;
}
#secondarymenu, #mainmenu {
background:#fff;
margin:0 -2%;
padding:0 2%;
margin-top:10px;
}
#bgr {
width:100%;
}
#secondarymenu li, #mainmenu li {
border-top:1px solid #eee;
}
.footer-widgets .widgetf:first-child {
border:none;
}
#footer {
width:100%;
}
.widgetf {
border-top:1px solid #45362d;
}
}