body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background-color: steelblue;
}

/* HEADER */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100px;
  display: grid;
  grid-template-columns: 200px 1fr 200px;
  align-items: center;
  background: darkblue;
  color: white;
  z-index: 1000;
}

.logo {
  width: 200px;
  text-align: center;
}

.logo img {
  max-width: 100%;
}

.header-title {
  text-align: center;
}

/* MAIN */
main {
  margin-top: 100px;
  margin-bottom: 80px;
  height: calc(100vh - 180px);
  display: grid;
  grid-template-columns: 200px 1fr 200px;
}

/* LEFT NAV */
.left-nav {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 20px;
  background: darkblue;
}

/* CONTENT */
.content {
  display: flex;
  align-items: center;
  justify-content: center;
}

.content img {
  max-width: 100%;
  max-height: 90%;
}

/* THUMBNAILS */
.thumbs {
  overflow-y: auto;
  padding: 10px;
  background: #ddd;
}

.thumbs img {
  width: 100%;
  margin-bottom: 10px;
  cursor: pointer;
  transition: transform 0.2s;
}

.thumbs img:hover {
  transform: scale(1.05);
}

/* FOOTER */
footer {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: grid;
  grid-template-columns: 200px 1fr 200px;
  align-items: center;
  background: darkblue;
  color: white;
  z-index: 1000;
}

.footer-nav {
  text-align: center;
}

button {
  padding: 10px 20px;
  margin: 0 10px;
  cursor: pointer;
}