#middle-page {
    text-align: center;
}
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
*::before,
*::after{
    box-sizing: border-box;
}
.app-flow-main > div {
    border-top: 1px solid #ddd;
}
img{
    max-width: 100%;
    vertical-align: top;
}
#main{
    margin: 80px auto 0 auto;
}
.gray-bg {
    background-color: #F8F8F8;
}
.white-bg {
    background-color: #ffffff;
}
.light-blue-bg {
    background-color: #ededfb;
}
.light-green-bg {
    background-color: #f0f4fd;
}
.light-purple-bg {
    background-color: #f0e4ff;
}
.light-sky-bg{
    background-color: #f4feff;
}
#midd-part1 div{
    text-align: center;
    border-bottom: 1px solid #ddd;
}