.round-img         {border-radius: 50%;   display: block; margin-left: auto; margin-right: auto; max-width: 80%;}
.row               {padding-left: 1em; padding-right: 1em}
nav .nav-link      {text-align: center; color:white}
.header-container  {position: relative; width: 100%; height: 300px; background-image: url(../images/banner.jpg); background-size: cover; background-position: center center;}
.title             {position: absolute; top: 50%; left: 50%; transform: translate(-50%, -70%); background-color: rgb(0,0,0); background-color: rgba(0,0,0,0.7); text-align: center; color: white; padding-right: 1em; padding-left: 1em;}
.title-centred     {text-align: center;}
.main-window       {min-height: 100vh; padding-bottom: 100px; overflow: hidden; display: block; position: relative;}
.footer            {color: white; position: absolute; bottom: 0; right: 0; width: 100%; padding-bottom: 10px; padding-top: 10px;}

@media screen and (min-width: 800px) {
    .nav-link         {margin-left: 3rem; margin-right: 3rem;}
    .round-img        {max-width: 80%;}
    .title h1         {font-size: 4rem}
    }