.mainMenu{
    width: 150px;
    display: block;
    border-radius: 10px;
    overflow: hidden;
}

.item{
    overflow: hidden;
}

.btn{
    display: block;
    padding: 16px 20px;
    background-color: #e0f2fe;
    color: #292524;
    position: relative;
}

/*.btn:before{*/
/*    content: '';*/
/*    position: absolute;*/
/*    width: 0;*/
/*    height: 0;*/
/*    border-left: 8px solid transparent;*/
/*    border-right:8px solid transparent;*/
/*    border-top:10px solid #e0f2fe;*/
/*    right: 15px;*/
/*    bottom: -10px;*/
/*    z-index: 9;*/
/*}*/

.subMenu{
    background: #e0f2fe;
    transition: max-height 0.7s;
    max-height: 0;
    z-index: 31;
}
.subMenu a{
    display: block;
    padding: 15px 20px;
    color: #44403c;
    font-size: 14px;
    border-bottom: 1px solid #e0f2fe;
    position: relative;
}
.subMenu a:before{
    content: '';
    opacity: 0;
    transition: opacity 0.3s;

}/*
.subMenu a:hover:before{
    content: '';
    position: absolute;
    height: 0;
    width: 6px;
    left: 0;
    top:0;
    opacity: 1;
    !* background-color: #d8d824; *!
    border-top: 24px solid transparent;
    border-left: 15px solid #3b82f6;
    border-bottom: 24px solid transparent;
    border-radius: 50%;
}
.subMenu a:after{
    content: '';
    opacity: 0;
    transition: opacity 0.3s;

}
.subMenu a:hover:after{
    content: '';
    position: absolute;
    height: 0;
    width: 6px;
    right: 0px;
    top:0;
    opacity: 1;
    !* background-color: #d8d824; *!
    border-radius: 50%;
    border-top: 24px solid transparent;
    border-right: 15px solid #3b82f6;
    border-bottom: 24px solid transparent;
}*/
.subMenu a:hover{
    background: #bae6fd;
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#273057', endColorstr='#394c7f',GradientType=0 );
    transition: all 0.3s;
    border-bottom: 1px solid #e0f2fe;
}
.subMenu a:last-child{
    border:none;
}
.item:target .subMenu{
    max-height: 20em;
}