body{background-color: rgba(0, 98, 182, 1);color: #fff;font-size: 20px;padding-top: 126px}
*{margin:0;padding: 0;box-sizing: border-box}
li{list-style: none}
a{cursor: pointer}
.container{width: 1200px;margin: 0 auto}
.display_flex{display: flex}
.flex_1{flex: 1}
.flex_2{flex: 2}
.flex_3{flex: 3}
.clearfix:after, .clearfix:before {content: "";display: block;clear: both;}
.float_l{float: left}
.float_r{float: right}

.text_center{text-align: center}

.font_size_28{font-size: 28px}
.font_weight_500{font-weight: 500}

.text_color_ccc{color: #ccc}

.line_height_2{line-height: 2}
.line_height_3{line-height: 3}

.margin_top_30{margin-top: 30px}
.margin_top_20{margin-top: 20px}

header{padding: 16px 0;line-height: 64px;height: 96px; position: fixed;top: 0;background-color: rgba(0, 98, 182, 1);width: 100%}
header img{vertical-align: middle}
header h1{font-size: 20px;font-weight: 500}
header .nav_item:not(:last-child){margin-right: 50px;}
.download_btn{text-decoration: none;display: block; width: 230px;height: 62px;line-height: 62px;border-radius: 3px;font-size: 28px; background-color: #fff;color: #000;margin: 50px 10px;text-align: center}
.part_1 .left{padding:  20px 0 0 20px}
.part_1 .right img{width: 100%;height: 100%}
.part_2 h3{position: relative}
.part_2 h3::after{content: "";position:absolute;bottom:-10px;left: 50%; width: 200px;height: 4px;background-color: #fff;margin-left: -100px;}
.part_2 ul{width: 820px;  margin: 50px auto;}
.part_2 li{float: left;width: 50%;padding-left: 92px;line-height: 3;}

footer{background-color: rgba(0, 51, 204, 1);text-align: center;padding: 40px 0;border-top: 1px solid rgba(121, 121, 121, 1);color: #ccc}
footer a{color: #fff}