Great theme! I love it. I made an edit so I could see the blockquotes better and themed the account menu as well if you would like to include it!

.Markdown blockquote > p {
     color: rgba(255, 255, 255, 0.6);
}
  
.menu.vertical > li > a {
    color: #59989c;
    background-color: rgb(51, 51, 51);
}
.dropdown-pane {
    border: 1px solid #59989c;
}  
  
.VerticalMenu > li.title {
    padding: 0.4rem;
    font-weight: 700;
    text-align: center;
    background-color: rgb(51, 51, 51);
    border-bottom: 1px solid rgb(89, 152, 156);
}

Here are some screenshots of the changes as well.