.flex{
    display: flex;
}
.relative{
    position: relative;
}
.absolute{
    position: absolute;
}
.fixed{
    position: fixed;
}

.f-j-c{
    justify-content: center;
}
.f-a-c{
    align-items: center;
}
.bet{   
    justify-content: space-between;
}
*{
    box-sizing: border-box;
}