Как указать браузеру , что информация на сайте обновилась, в частности в style.css не используя ctrl+f5?

Клиент это не всегда продвинутый пользователь, который знает как обновить страницу при помощи ctrl+f5. Как выйти из этой ситуации? прочитал несколько форумов, но что-то не понимаю как это сделать в style.css. Помогите пожалуйста! Файл размещён на сервере. Можно по подробнее куда и что надо прописать? Прикладываю файл со стилями style.css.

@import "http://webfonts.ru/import/arnamuserif.css";
ul{
    margin: 0; padding: 0; list-style: none;
}
img{margin: 0; padding:0; border: 0;}
p{padding: 0 0 13px 0; margin: 0; }
a{ color: #2185c5; }
.clearfix:after {
    content: ".";
    clear: both;
    height: 0;
    font-size:0;
    visibility: hidden;
    display: block;
}
.clearfix {
    display: inline-block; /* Fixes IE/Mac */
}
/* Hides from IE-mac \*/
* html .clearfix {height: 1%;}
.clearfix {display: block;}
/* End hide from IE-mac */
html, body{
    margin: 0; padding: 0;
    min-width: 1000px;
}
body{
    background: #fff;
    font-family: 'Arian AMU Serif', Tahoma, sans-serif;
    color: #ffffff;
}
h1,h2,h3{
    font-family: 'Arian AMU Serif', Tahoma, sans-serif;
}
.p_header{
    position: fixed;
    left: 0; top: 0; right: 0;
    height: 58px;
    background: rgba(0,0,0,0.2);
    z-index: 10;
}
.p_header ul{
    display: block;
    width: 1000px; height: 58px;
    margin: 0 auto;
    padding: 0 0 0 30px;
}
.p_header ul li{
    float: left;
}
.p_header ul li a{
    display: block;
    font-size: 18px;
    line-height: 58px;
    color: #fff;
    text-transform: uppercase;
    text-decoration: none;
    text-align: center;
    padding: 0 16px;
}
.p_header ul li.active a{
    color: #36a1ff;
    text-decoration: underline;
}
.p_header ul li:first-child a{
    text-align: left;
    padding: 0 21px 0 0;
}
.p_header ul li:last-child a{
    text-align: right;
    padding: 0 0 0 21px;
}
.p_center{
    z-index: 1;
    min-height: 980px;
    padding: 58px 0 0 0;
}
.p_center.main{
    background: url(images/bg_main.jpg) top center fixed;
    height: 100%;
    position: relative;
    overflow: hidden;
    width: 100%;
}
.p_center.about{
    background: url(images/bg_about.jpg) top center fixed;
    height: 100%;
    position: relative;
    overflow: hidden;
    width: 100%;
}
.p_center.benefits{
    background: url(images/bg_benefits.jpg) top center fixed;
    height: 100%;
    position: center;
    overflow: hedden;
    width: 100%;
}
.p_center.location{
    background: url(images/bg_location.jpg) top center fixed;
    height: 100%;
    position: center;
    overflow: hedden;
    width: 100%;
}
.p_center.news{
    background: url(images/bg_news.jpg) no-repeat 50% 0;
}
.p_center.promotions{
    background: url(images/bg_promotions.jpg) top center fixed;
    height: 100%;
    position: relative;
    overflow: hidden;
    width: 100%;
}
.p_center.quality{
    background: url(images/bg_quality.jpg) no-repeat 50% 0;
}
.p_center.houses,
.p_center.house1,
.p_center.house2,
.p_center.house3,
.p_center.house4,
.p_center.house5,
.p_center.house6,
.p_center.townhouses,
.p_center.cottages,
.p_center.cotta1,
.p_center.cotta2,
.p_center.cotta3,
.p_center.cotta4,
.p_center.cotta5,
.p_center.cotta6,
.p_center.cotta7,
.p_center.cotta8,
.p_center.cotta9,
.p_center.cotta10,
.p_center.cotta11,
.p_center.cotta12,
.p_center.cotta13,
.p_center.cotta14,
.p_center.cotta15,
.p_center.cotta16,
.p_center.cotta17,
.p_center.cotta18,
.p_center.map1,
.p_center.map2,
.p_center.map3
{
    background: url(images/bg_houses.jpg) top center fixed;;
}
.p_center.contacts{
    background: url(images/bg_contacts.jpg) no-repeat 40% 0;
}
.p_center .inner{
    position: relative;
    width: 1000px;
    margin: 0 auto;
}
.p_center .main_map{
    position: absolute;
    left: 0; top: 30px;
    width: 190px; height: 167px;
    background: url(images/img_map.png) no-repeat;
}
.p_center .main_sale_count{
    position: absolute;
    left: 220px; top: 30px;
    width: 100px;
    text-align: center;
    font-size: 14px;
    line-height: 1.2;
}
.p_center a.main_logo{
    position: absolute;
    left: 392px; top: 30px;
    width: 215px; height: 168px;
    background: url(images/logo.png) no-repeat;
}
.p_center a.main_download_buklet{
    position: absolute;
    left: 642px; top: 30px;
    border: 1px solid #ffffff;
    text-transform: uppercase;
    border-radius: 10px;
    padding: 10px 10px 8px 10px;
    font-size: 14px;
    line-height: 14px;
    color: #ffffff;
    text-decoration: none;
}
.p_center .main_contacts{
    position: absolute;
    top: 30px; right: 0;
    padding: 0 0 0 30px;
    background: url(images/ic_phone.png) no-repeat 0 8px;
}
.p_center .main_contacts.map{
    z-index: 10;
    top: 80px; right: 50px;
}
.p_center .main_contacts div{
    color: #fff;
    font-size: 18px;
    line-height: 1.5;
}
.p_center .main_contacts button{
    color: #fff;
    font-size: 14px;
    line-height: 1;
    background: #36a1ff;
    border: 0;
    padding: 6px 20px;
    border-radius: 2px;
    cursor: pointer;
}
.p_center h1.main{
    position: absolute;
    left: 0; right: 0; top: 200px;
    text-align: center;
    font-size: 30px;
    line-height: 1.2;
    color: #fff;
    text-shadow: 1px -2px 2px #000;
    text-transform: uppercase;
}
.p_center .main_select_house{
    position: absolute;
    left: 0; right: 0; top: 794px;
    text-align: center;
}
.p_center .main_discount{
    position: absolute;
    left: 0; right: 0; top: 867px;
    text-align: center;
}
.p_catalog{
    position: absolute;
    left: 0; right:0; top: 470px;
    background: #ffffff;
    border-radius: 10px;
    height: 300px;
    padding: 0 25px;
}
.p_catalog .item{
    float: left;
    width: 190px; height: 300px;
    padding: 10px 8px;
    box-sizing: border-box;
    color: #000;
}
.p_catalog .item:hover{
    background: #c4c4b1;
}
.p_catalog .item .address{
    border-bottom: 2px dashed #e2dfe0;
    text-align: center;
    padding: 0 0 10px 0;
    margin: 0 0 15px 0;
}
.p_catalog .item .title{
    text-align: center;
    text-transform: uppercase;
    font-size: 13px;
    line-height: 1.4;
    margin: 0 0 10px 0;
}
.p_catalog .item .price{
    font-size: 18px;
    line-height: 1;
    text-align: center;
    color: #fff;
    background: #ff0000;
    border-radius: 3px;
    width: 120px;
    padding: 6px 0;
    margin: 0 0 15px 27px;
}
.p_catalog .item .image{
    width: 174px; height: 94px;
    margin: 0 0 15px 0;
    border-radius: 5px;
}
.p_catalog .item a.more{
    display: block;
    width: 172px; height: 30px;
    border: 1px solid #000;
    font-size: 14px;
    text-transform: uppercase;
    line-height: 30px;
    text-align: center;
    color: #000;
    border-radius: 5px;
    cursor: pointer;
}

.p_progress{
    background: #ffffff;
}
.p_progress .inner{
    position: relative;
    width: 1000px; height: 140px;
    margin: 0 auto;
}
.p_progress .hand{
    position: absolute;
    left: 0; top: 65px;
    width: 33px; height: 15px;
    background: url(images/img_pg_hand.png) no-repeat;
}
.p_progress .arrow{
    position: absolute;
    left: 60px; top: 65px;
    width: 890px; height: 22px;
}
.p_progress .arrow li{
    height: 22px;
}
.p_progress .arrow li.back{
    position: absolute; width: 100%;  z-index: 1;
    background: url(images/img_pg_arrow.png) no-repeat;
}
.p_progress .arrow li.active{
    position: absolute; z-index: 2;
    width: 0%;
    background: url(images/img_pg_arrow_a.png) no-repeat;
}
.p_progress .arrow li.knight{
    position: absolute;
    left: 0; top: -50px;
    min-width: 97px; height: 60px;
    background: url(images/img_pg_knight.png) no-repeat 100% 0;
    width: 15%;
}
.p_progress .arrow.about li.active{ width: 15%; }
.p_progress .arrow.about li.knight{ width: 25%; }
.p_progress .arrow.benefits li.active{ width: 30%; }
.p_progress .arrow.benefits li.knight{ width: 40%; }
.p_progress .arrow.location li.active{ width: 45%; }
.p_progress .arrow.location li.knight{ width: 55%; }
.p_progress .arrow.promotions li.active{ width: 55%; }
.p_progress .arrow.promotions li.knight{ width: 65%; }
.p_progress .arrow.quality li.active{ width: 65%; }
.p_progress .arrow.quality li.knight{ width: 75%; }
.p_progress .arrow.houses li.active{ width: 80%; }
.p_progress .arrow.houses li.knight{ width: 90%; }
.p_progress .arrow.contacts li.active{ width: 100%; }
.p_progress .arrow.contacts li.knight{ width: 100%; }


/*
.p_progress .arrow{
    position: absolute;
    left: 60px; top: 65px;
    width: 890px; height: 22px;
}
.p_progress .arrow:after{
    content: "";
    position: absolute;
    height: 22px; width: 50%;
    background: url(images/img_pg_arrow_a.png) no-repeat;
    z-index: 2;
}
*/
.p_footer{
    background: #ecece5 url(images/bg_footer_top.png) repeat-x;
    position: inherit;
    left: 0; bottom: 0;
    padding: 10px;
    width: 100%;
}
.p_footer .inner{
    position: relative;
    width: 1000px; height: 200px;
    margin: 0 auto;
}
.p_footer .logo{
    position: absolute;
    left: 0; top: 25px;
    width: 113px; height: 89px;
    background: url(images/logo_footer.png);
}
.p_footer .copyright{
    position: absolute;
    left: 140px; top: 50px;
    font-size: 14px;
    line-height: 1;
    color: #000;
}
.p_footer .convention{
    position: absolute;
    left: 450px; top: 50px;
    font-size: 14px;
    line-height: 1;
    color: #000;
}
.p_footer .contacts{
    position: absolute;
    right: 0px; top: 25px;
    color: #000;
    background: url(images/ic_phone2.png) no-repeat 0 27px;
    padding: 0 0 0 30px;
}
.p_footer .contacts label{
    display: block;
    font-size: 13px;
    line-height: 1;
    margin: 0 0 10px -30px;
}
.p_footer .contacts div{
    text-align: right;
    margin: 0 0 5px 0;
}
.p_footer .contacts a{
    display: block;
    font-weight: bold;
    color: #000;
    text-decoration: none;
}
.p_footer .contacts button{
    color: #fff;
    font-size: 14px;
    line-height: 1;
    background: #36a1ff;
    border: 0;
    padding: 6px 20px;
    border-radius: 2px;
    margin: 5px 0 0 -10px;
    cursor: pointer;
}

.p_map{
    margin: -58px 0 0 0;
    width: 100%;
    height: 1030px;
}
.p_map_info_box{
    position: absolute;
    left: -165px; top: 155px;
    background: #ffffff;
    width: 300px;
    border-radius: 10px;
    padding: 15px;
    color: #000;
    text-align: center;
    font-size: 14px;
}
.p_map_info_box2{
    width: 300px;
    color: #000;
    text-align: center;
    font-size: 14px;
    padding: 10px 0 0 0;
}
.p_map_info_box .title{
    line-height: 1;
    text-transform: uppercase;
    margin: 0 0 20px 0;
}
.p_map_info_box .title span{
    border-bottom: 1px solid #000;
}
.p_map_info_box p{
    margin: 0 0 10px 0;
}
.p_map_info_box .phone{
    margin: 0 0 20px;
}
.p_map_info_box .phone a{
    font-size: 18px;
    color: #000;
    text-decoration: none;
    font-weight: bold;
}
.p_map_info_box .notice{
    padding: 10px;
    background: #36a1ff;
    color: #ffffff;
}
.p_benefits{
    position: static;
    top: auto; left: 0; right: 0;
    text-align: center;
}
.p_benefits li{
    display: inline-block;
    width: 240px;
    margin: 0 0 10px 0;
    vertical-align: top;
}
.p_benefits h2{
    font-size: 18px;
    line-height: 1.2;
    text-transform: uppercase;
    margin: 0 0 10px 0;
}
.p_benefits img{
    margin: 0 0 10px 0;
}
.p_benefits p{
    font-size: 14px;
    line-height: 1.4;
}
.p_text{
    padding: 350px 30px 0 30px;
}
.p_text .img{
    text-align: center;
    margin: 0 0 20px 0;
}
.p_text h1{
    font-size: 18px;
    line-height: 1;
    margin: 0 0 20px 0;
    padding: 0;
    text-align: center;
    text-transform: uppercase;
}
.p_text p{
    font-size: 18px;
    line-height: 1.4;
    margin: 0 0 20px 0;
    text-align: justify;
}
.popup_back{
    display: none;
    background: rgba(0,0,0,0.6);
    position: fixed;
    left: 0; right: 0; top: 0; bottom: 0;
    z-index: 100;
}
.popup_callme{
    position: relative;
    margin: 200px auto 0 auto;
    width: 368px; height: 388px;
    background: url(images/bg_popup_callme.png) no-repeat;
}
.popup_callme .close{
    position: absolute;
    right: 35px; top: 70px;
    width: 16px; height: 16px;
    background: url(images/ic_popup_close.png) no-repeat;
    cursor: pointer;
}
.popup_callme form{
    padding: 100px 0 0 80px;
}
.popup_callme input{
    width: 210px;
    box-sizing: border-box;
    padding: 8px 10px;
    border: 1px solid #c2c2c2;
    margin: 0 0 20px 0;
    text-align: center;
    font-size: 14px;
    line-height: 1;
    color: #000;
}
.popup_callme button{
    width: 210px;
    box-sizing: border-box;
    padding: 8px 10px;
    border: 0;
    margin: 0 0 20px 0;
    text-align: center;
    font-size: 14px;
    line-height: 1;
    background: #36a1ff;
    color: #ffffff;
    cursor: pointer;
}
.p_quality{
    position: absolute;
    top: 280px; left: 0; right: 0;
    height: 639px;
    background: url(images/bg_quality.png) no-repeat;
    padding: 30px 0 0 85px;
}
.p_quality .text{
    width: 530px; height: 570px;
    overflow: hidden;
    overflow-y: scroll;
    color: #ffffff;
    padding: 0 100px;
}
.p_quality .text table{
    border-top: 1px solid #ffffff;
    border-left: 1px solid #ffffff;
}
.p_quality .text table td{
    border-right: 1px solid #ffffff;
    border-bottom: 1px solid #ffffff;
    vertical-align: top;
}
.p_quality .text::-webkit-scrollbar {
    width: 15px;
    background-color: rgba(0, 44, 68, 0.35);
    -webkit-border-radius: 10px;
    -moz-border-radius: 10px;
    -khtml-border-radius: 10px;
    border-radius: 10px;
}
.p_quality .text::-webkit-scrollbar-thumb {
    background-color: #36a1ff;
    -webkit-border-radius: 10px;
    -moz-border-radius: 10px;
    -khtml-border-radius: 10px;
    border-radius: 10px;
}
.p_promo{
    display: block;
    width: 562px; height: 162px;
    background: url(images/bg_promotion2.png) no-repeat -300px -330px;
    margin: 0 0 0 189px;
    font-size: 24px;
    line-height: 40px;
    text-align: center;
    padding: 40px 0 0 0;
    box-sizing: border-box;
}
.p_promo big{
    font-weight: bold;
}
.p_promo2{
  padding-top: 300px;
    position: relative;
}
.p_promo2:after{
    position: absolute;
    width: 800px;
    height: 360px;
    background: url(images/bg_promotion2.png) no-repeat 0 0;
    content: "";
}


.header-txt{
    text-transform: uppercase;
    border-top: 2px solid #fff;
    border-bottom: 2px solid #fff;
    padding: 5px 5px;
    font-size: 30px;
    margin-top: 20px;
    margin-bottom: 30px;
    display: inline-block;
    letter-spacing: 3px;
}
.header-info{
    text-align: center;
    font-size: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid #fff;
    text-align: left;
}

/* Gallery */
.gallery img{
    margin:5px;
    border:3px solid #fff;
}
a.photo:hover img{
border:3px solid #1E90FF;   
}   
.p_card{
padding: 330px 0px 0 0px;
}