html {
    background-color: #FACE6F;
}
.nav {
    background-color: #5286FF;
    text-align: center;
     position: fixed;
     margin: 0;
     top: 0;
     z-index: 999;
     height: 85px;
     width: 100%;
}

        .nav #btn {
            border: none;
            background-color: #5286FF;
            color: white;
            font-size: 65px;
        }

        .Courses {
            background: #BD9FF1;
            overflow: hidden;
            line-height: 1250%;
            font-size: 145%;
            text-align: center;
            transition: all .3s ease-in-out;
            height: 0;
        }

     .Courses:target {
        height: 300px;
     }

    #basics {
        color: #FFC100;
        font-size: 75px;
    }

    .about-softuni {
        left: 50%;
        top: 50%;
        margin-left: 500px;
        margin-top: 50px;
    }

    #part-1 {
        background: #FAF5F5;
        position: fixed;
        border: 5px solid black;
        color: #4A4242;
        font-size: 200%;
        z-index: 997;
    }

    #part-2 {
        background: #FAF5F5;
        position: absolute;
        border: 5px solid black;
        color: #4A4242;
        font-size: 35px;
        left: 50%;
        top: 50%;
        margin-left: -500px;
        margin-top: 550px;
        z-index: 999;
    }

    .certificates {
        background: black;
        position: absolute;
        left: 50%;
        top: 50%;
        margin-left: -500px;
        margin-top: 550px;
        z-index: 998;
    }

    h3 {
        text-align: center;
        font-size: 150px;
        color: white;
        padding-top: 1500px;
    }