.midashi17{
    position: relative;
    margin: 0 0 1.5em;
    padding: 0.5em 0.5em 0.2em 2.0em;
    border-bottom: 2px solid #006400; 
    font-size: 1.25em; 
    font-weight: bold; 
    color: #000000;
} 
.midashi17:before{
    content: "□";
    font-size: 180%;
    position: absolute;
    color: #ff8c00;
    top: -0.4em;
    left: 0.3em;
    height: 12px;
    width: 12px;
}
.midashi17:after{
    content: "□";
    font-size: 200%;
    position: absolute;
    color: #00008b; 
    top: -0.2em;
    left: 0;
    height: 12px;
    width: 12px;
}