/* flex */
.flex{
    display: flex;
}

.flex-ai-center{
    display: flex;
    align-items: center;
}
.flex-end{
    display: flex;
    align-items: flex-end;
}
.flex-jc-center{
    display: flex;
    justify-content: center;
}
.flex-middle{
    display: flex;
    justify-content: center;
    align-items: center;
}
.flex-ac-between{
    display: flex;
    align-content: space-between;
}
.flex-jc-between{
    display: flex;
    justify-content: space-between;
}
.flex-wrap{
    display: flex;
    flex-wrap: wrap;
}
.flex-column{
    display: flex;
    flex-direction: column;
}

/* font */
.letter-font{
    /* letter-spacing: 2.0px; */
    font-family: "微软雅黑";
}