* {
  box-sizing: border-box;
}

body {
  font-family: Arial;
  padding: 20px;
  background: #f1f1f1;
  background-image: url(img/bg.png);
  background-repeat: no-repeat;
  background-size: cover;
}

/* Center the whole website */

.row {
    padding-top: 20px;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
}

/* Header/Blog Title */
.header {
  text-align: center;
}

/* Ribbon */
.ribbon {
  margin-top: 20px;
}

.tree-view summary {
    cursor: pointer;
}

/* Create two unequal columns that floats next to each other */
/* Left column */
.left-sidebar {
  float: left;
  width: 25%;
  padding-right: 20px;
}

/* Right column */
.right-sidebar {
  float: left;
  width: 25%;
  padding-left: 20px;
}

/* Right column */
.middlecolumn {
  float: left;
  width: 50%;
}

/* Fake image */
.fakeimg {
  background-color: #aaa;
  width: 100%;
  padding: 20px;
}

/* Add a card effect for articles */
.card {
  background-color: white;
  padding: 20px;
  margin-top: 20px;
}

/* Clear floats after the columns */
.row:after {
  content: "";
  display: table;
  clear: both;
}

/* Footer */
.footer {
  text-align: center;
  margin-top: 20px;
}

marquee {
  float: center;
}

/* Responsive layout - when the screen is less than 800px wide, make the two columns stack on top of each other instead of next to each other */
@media screen and (max-width: 800px) {
  .leftcolumn, .rightcolumn {
    width: 100%;
    padding: 0;
  }
}