.tit_style12 {
 font-size: 24px;
 font-size: 2.4rem;
 letter-spacing: 0.1em;
 font-weight: bold;
 border-bottom: 1px solid #999;
 padding: 0 0 10px;
 position: relative;
 margin: 0 0 35px;
 text-align: center;
}
 
.tit_style12::after {
 content: '';
 position: absolute;
 bottom: -2px;
 left: 50%;
 transform: translateX(-50%);
 width: 100px;
 height: 3px;
 background: var(--main-color);
}
 
@media (max-width : 810px){
.tit_style12 {
 font-size: 22px;
 font-size: 2.2rem;
}
}