body {
    max-width: 880px;
    margin: auto;
    font-family: Georgia, serif;
    padding-left: 23px;
    padding-right: 23px;
    background-color: #F7F7F7;
    
}

ul {
    list-style-type: none;
    
    line-height: 20px;
    padding: 0;
}
li {
    
    padding-top: 10px;
    padding-bottom: 10px;
    padding-left: 10px;
}
#toc li {
    border-bottom: 1px;
    border-left: 1px;
    border-right: 1px;
    border-left: solid;
    border-right:solid;
    border-bottom: solid;
    border-color: #d4d4d4;
    
}

li:hover {
    background-color: darkgray;
    cursor: pointer;

}

.innerList li {
    background-color: #f2f2f2;
    padding-left: 40px;
}

a {
    text-decoration: none;
    color: black;   
}

#collapseContent {
    display: none;
    margin: 0;
    border-top: solid;
    border-color: #d4d4d4;
    border-top-width: 3px;
    z-index: 2;
    
    background-color: white;
    margin-bottom: 50px;
}

#toc {
   max-width: 400px;
}

h1 {

    font-size: 50px;
    margin-top: 10px;
    
    font-weight: 900;
}

h2 {
    margin-top:50px;
    margin-bottom: 10px;
}

img {
    width: 100%;
    margin-bottom: 30px;

}

p {
    line-height: 28px;
    font-size: 17px;
    color: #292929;
}

blockquote {
    font-style: italic;
    color: darkgray;
    margin-left: 23px;
    opacity: .8;
}


.contentTitle {
    color:gray;
    transition: ease;
    margin-top: 20px;

    
    padding-top: 15px;
    padding-bottom: 15px;
}

.contentTitle:hover {
    color: darkgray;
    cursor: pointer;
    
}

#back-to-top {
    position: fixed;
    bottom: 13px;
    left: 13px;
    border: none;
    outline: none;
    
    width: 120px;
    height: 40px;
    font-size: 14px;
    font-weight: bold;
    
    background-color: white;    
    font-family: Georgia;
    
    
}

#back-to-top:hover {
    cursor: pointer;
    background-color: lightgray;
}

#back-to-top:active {
   
}


@media (max-width: 900px) {
    
    #back-to-top {
        width: 100%;
        height: 60px;
        bottom: 0;
        left: 0;
        background-color: #EDEDED;
        border-top: solid;
        border-top-width: 2px;
        border-top-color: lightgray;   
    }
    
    img {
        margin-bottom: 10px;
    }

    .contentTitle {
        margin-bottom: 0px;
    }
    
    
    h1 {
        font-size: 35px;
    }
}