*{text-transform: math-auto;}

.header__menu-item:hover span {text-decoration: none;color: #399e96;}
.header__active-menu-item {text-decoration: none;}
.details[open]>.header__menu-item{text-decoration:none}
.header__menu-item:hover{text-decoration:none;}
details[open]:hover>.header__menu-item{text-decoration:none}
details[open]>.header__menu-item{text-decoration:none}
.mega-menu__link--active{text-decoration:none}
.mega-menu__link:hover{text-decoration:none;color:#399e96}