#flex_box{
                height: 100vh;
                position: absolute;
                top: 0;
                left: 0;
                width: 100%;
                text-align: center;
                display: flex;
                flex-direction: row;
                flex-wrap: nowrap;
                align-content: center;
                justify-content: center;
                align-items: center;
                z-index: 11111;
                
            }
            .bj{position:fixed;top:0;left:0;width:100%;height:100%;background:#000;opacity: .6;z-index:111;}
            .bj_img{position:fixed;top:0;left:0;}
            #flex_box a{
                background: #fff;
                display: flex;
                margin: 15px;
                flex-direction: row;
                flex-wrap: nowrap;
                align-content: center;
                justify-content: center;
                align-items: center;
                border: 1px solid #ccc;
                padding: 8px 20px;
                border-radius: 8px;
                transition: all 0.5s;
            }
            #flex_box a:hover{
                background-color: #000;
                color: #fff;
            }
            #flex_box a img{
                vertical-align: middle;
                margin-right: 5px;
            }