.main.about_us{width: 100%;}

.introduction{width: 900px; margin: 0px auto;}
.introduction span{display: inline-block;}
.introduction_content{width: 630px;}
.introduction_content p{margin-bottom: 0px;}
.introduction_content p:not(:first-child){margin-top: 24px;}
.introduction img{max-width: 229px; vertical-align: top; margin-left: 36px;}
.colon{ width: 50px; height: 38px; background: url("../img/about_us/colon.png"); display: inline-block;}

.culture{ height: 320px; background-color: #dc251f; padding: 70px 0px;}
.culture_content{width: 100%; height: 180px; margin: 0px auto;}
.culture_content ul{ list-style: none; padding: 20px 0px 0px;}
.culture_content ul li{ width: 25%; float: left; text-align: center; position: relative;}
.culture_content ul li p{ font-size: 18px; color: #ffffff; margin-bottom: 5px;}
.culture_content ul li span{display: block; width: 1px; height: 180px; top: -20px; right: 0; background: #e35d52; position: absolute;}
.culture_content .title{ font-family: "Cpcn Font Normal"; font-size: 30px; color: #ffffff; margin-bottom: 30px;}

.course{width: 900px; margin: 30px auto 0px; list-style: none; padding: 0px;}
.course_text{width: 265px;}
.course_square{ width: 6px; height: 29px; background-color: #e8343b;}
.course_year{ width: 135px; height: 60px; background: url("../img/about_us/years.png") no-repeat; margin: 0px 40px;}
.year_2019{background-position:0px -600px;}
.year_2018{background-position:0px -540px;}
.year_2017{background-position:0px -480px;}
.year_2016{background-position:0px -420px;}
.year_2015{background-position:0px -360px;}
.year_2014{background-position:0px -300px;}
.year_2013{background-position:0px -240px;}
.year_2012{background-position:0px -180px;}
.year_2011{background-position:0px -120px;}
.year_2010{background-position:0px -60px;}
.year_2005{background-position:0px 0px;}

.course li.odd .course_text,
.course li.odd .course_square,
.course li.odd .course_year{float: right;}
.course li.even .course_text,
.course li.even .course_square,
.course li.even .course_year{float: left;}

.course li.odd .course_text{text-align: left;}
.course li.even .course_text{text-align: right;}
<!-- 
.course li.odd .course_text .course_text_title{text-align: left;}
.course li.even .course_text .course_text_title{text-align: right;}

.course li.even .course_text .course_text_content{text-align-last: right;-moz-text-align-last: right;}
-->
.course li.odd .course_text{ border-left: solid #e8343b 1px; padding-left: 20px;}
.course li.even .course_text{ border-right: solid #e8343b 1px; padding-right: 20px;}

.banner_about_us{background: url("../img/about_us/banner_01.jpg") no-repeat center;}

#main-slider .item{height: 670px !important;}

.modal-dialog {
    width: 630px;
}

.btn_commitmentLetter{ display: block; width: 374px; height: 74px; margin: 0 auto ; background: url("../img/about_us/btn_commitmentLetter.png") no-repeat;}
.btn_commitmentLetter:hover{background: url("../img/about_us/btn_commitmentLetter_on.png") no-repeat;}