.main_nav li a {
    text-transform: none !important;
    font-size: 14px !important;
}

@media only screen and (min-width:1200px) {
    .sitelogo {
        width: 45%;
    }

    .main_nav_contaner {
        width: 70%;
    }

    .bosluk {
        margin-top: 154px;
    }

    h1.about_title.mt-5 {
        font-size: 29px;
        border-bottom: solid;
        width: 100%;
        float: left;
        text-align: center;
    }
}

@media only screen and (min-width:992px) and (max-width:1199px) {
    .sitelogo {
        width: 45%;
    }

    .bosluk {
        margin-top: 154px;
    }

    h1.about_title.mt-5 {
        font-size: 29px;
        border-bottom: solid;
        width: 100%;
        float: left;
        text-align: center;
    }
}

@media only screen and (min-width:769px) and (max-width:991px) {
    .sitelogo {
        width: 45%;
    }

    .bosluk {
        margin-top: 154px;
    }

    h1.about_title.mt-5 {
        font-size: 29px;
        border-bottom: solid;
        width: 100%;
        float: left;
        text-align: center;
    }
}

@media only screen and (min-width:481px) and (max-width:768px) {
    .sitelogo {
        width: 45%;
    }

    .bosluk {
        margin-top: 154px;
    }

    h1.about_title.mt-5 {
        font-size: 29px;
        border-bottom: solid;
        width: 100%;
        float: left;
        text-align: center;
    }
}

@media only screen and (min-width:0px) and (max-width:480px) {
    .sitelogo {
        width: 138px !important;
        max-width: 193px !important;
    }

    .bosluk {
        margin-top: 15px;
    }

    h1.about_title.mt-5 {
        font-size: 29px;
        border-bottom: solid;
        width: 100%;
        float: left;
        text-align: center;
    }
}