@media screen and (max-width:720px){


    main {padding:20px;}
    .main_bg {width:100%; padding:10px;}
    /* header */
    .header_bg header {position:relative; height:70px; padding:0 10px;}
    .header_bg header .gnb {display:none;}
    .header_bg header h1 a img {height:20px;}
    /* header > m_nav */
    .header_bg header .m_nav {display:block;}
    .header_bg header .m_nav img {width:35px;}
    .header_bg header .m_nav_open {
        position:absolute; right:10px; top:70px; display:block; width:100px;
    }
    .header_bg header .m_nav_open a {
        color:#222; display:flex; flex-flow:column; align-items:center; padding:10px; transition:0.3s;
        background-color:#fff; border-radius:10px; justify-content:center; width:100%;
        margin-bottom:10px; box-shadow:1px 1px 1px rgba(0,0,0,0.2); font-size:14px; font-weight:700;
    }
    .header_bg header .m_nav_open a:nth-of-type(2) {background-color:#19b8d1;}
    .header_bg header .m_nav_open a:hover {
        background-color:#19b8d1; color:#222; transition:all 0.3s ease; text-shadow:1px 1px 1px rgba(0,0,0,0.2);
    }
    /* product_sub_p1 */
    .main_bg .p1_product_info {flex-flow:column;}
    .main_bg .p1_product_info .p1_left {width:100%; display:flex; flex-flow:column nowrap;}
    .main_bg .p1_product_info .p1_left .big {width:100%; height:300px;} 
    .main_bg .p1_product_info .p1_left .big img {width:100%; height:300px;}
    .main_bg .p1_product_info .p1_left .p1_left_btm {flex-flow:row nowrap;}
    .main_bg .p1_product_info .p1_left .p1_left_btm .small {width:30%; margin-right:20px;}
    .main_bg .p1_product_info .p1_right {width:100%;}
    .main_bg .p1_product_info .p1_right .p1_right_top {padding:70px 0 20px 0;}
    .main_bg .p1_product_info .p1_right .p1_right_top p {font-size:16px;}
    .main_bg .p1_product_info .p1_right .p1_right_top h1 {font-size:32px;}
    .main_bg .p1_product_info .p1_right .p1_right_btm h2 {font-size:16px; margin:80px 0 20px 0;}
    .main_bg .p1_product_info .p1_right .p1_right_btm p {line-height:1.8; font-size:14px;}
    /* product_sub_p2 */
    .main_bg .p2_other_product {margin-top:80px; padding:80px 0 80px;}
    .main_bg .p2_other_product h1 {font-size:20px;}
    .main_bg .p2_other_product .p2_other_product_g a #category {font-size:14px; margin:10px 0 5px 0;}
    .main_bg .p2_other_product .p2_other_product_g a h2 {font-size:15px; margin-top:10px;}
    /* product_sub_p3 */
    .main_bg .p3_ssProcess .p3_sstxt_g h1 {padding-top:80px; font-size:20px;}
    .main_bg .p3_ssProcess .p3_sstxt_g p {font-size:14px; margin-bottom:80px;}
    .main_bg .p3_ssProcess .p3_process_g {flex-flow:column nowrap; margin-bottom:50px;}
    .main_bg .p3_ssProcess .p3_process_g .process {flex-flow:row nowrap; width:100%; justify-content:space-between;}
    .main_bg .p3_ssProcess .p3_process_g .process .process_top {width:28%; margin-bottom:40px;}
    .main_bg .p3_ssProcess .p3_process_g .process .process_top img {margin-bottom:0;}
    .main_bg .p3_ssProcess .p3_process_g .process1 .p1_top img:nth-of-type(1) {margin-bottom:10px;}
    .main_bg .p3_ssProcess .p3_process_g .process4 .p4_top img:nth-of-type(1) {margin-bottom:10px;}
    .main_bg .p3_ssProcess .p3_process_g .process .process_middle {
        width:28%; margin-bottom:40px; display:flex; justify-content:center; align-items:center;
    }
    .main_bg .p3_ssProcess .p3_process_g .process .process_middle #bar_title {font-size:15px; left:5%; top:25%; font-weight:500;}
    .main_bg .p3_ssProcess .p3_process_g .process .p2_middle #bar_title {font-size:12px; width:50px; top:15%;}
    .main_bg .p3_ssProcess .p3_process_g .process .process_btm {width:40%; margin-bottom:40px;}
    .main_bg .p3_ssProcess .p3_process_g .process .process_btm p {
        position:relative; right:0; top:0; font-size:14px; border:0; padding:0; text-align:left;
    }
    br {display:none;}
    /* footer */
    .footer_bg {height:350px;}
    .footer_bg footer {width:100%; padding:0 20px; flex-flow:column;}
    .footer_bg footer .footer_left {display:flex; flex-flow:column; margin-bottom:50px; align-items:center;}
    .footer_bg footer .footer_left h1 {}
    .footer_bg footer .footer_left h1 img {height:20px; margin-bottom:10px;}
    .footer_bg footer .footer_right {text-align:center; width:80%;}
    .footer_bg footer .footer_right p {font-size:14px; line-height:1.8;}
    br {display:none !important;}


}