* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background-color: #2c2c2c;
  color: white;
  font-family: Arial, sans-serif;
  font-size: 16px;
}

.topbar {
  background-color: #1f1f1f;
  height: 60px;
  position: sticky;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  padding-left: 220px;
  z-index: 100;
  overflow: auto;
}

/* The side navigation menu */
.sidebar {
  top: 60px; /* Start below header */
  margin: 0;
  padding: 0;
  height: calc(100% - 60px);
  width: 200px;
  background-color: #3a3a3a;
  position: fixed;
  overflow: auto;
}

/* Sidebar links */
.sidebar a {
  display: block;
  color: white;
  padding: 16px;
  text-decoration: none;
}

/* Active/current link */
/* #4a90e2 */
  .sidebar a.active {
  background-color: #e67e22;
  color: #1f1f1f;
}

/* Links on mouse-over */
.sidebar a:hover:not(.active) {
  background-color: #4a4a4a;
  color: white;
}

/* Page content. The value of the margin-left property should match the value of the sidebar's width property */
.content {
  margin-left: 200px;
  margin-top: 60px; /* Push below header */
  padding: 20px;
}

/* Responsive - tablet */
@media screen and (max-width: 700px) {
  .topbar {
    font-size: 20px;
    padding-left: 0px;
    justify-content: center;
  }
  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
  }
  .sidebar a {float: left;
  }
  .content {margin-left: 0;
  }
}

/* Responsive - mobile */
@media screen and (max-width: 400px) {
  .topbar {
    font-size: 16px;
  }
  .sidebar a {
    text-align: center;
    float: none;
  }
}