body {
  font-family: sans-serif;
  background-color: #f2f2f2;
  margin: 10px;
  animation: bg-change 5s ease-out;
}

@keyframes bg-change{
  from { background-color: #c6ecf8 ; }
  to { background-color: #f2f2f2; }
}

html {
  overflow: -moz-scrollbars-vertical;
}

header {
  display: flex;
  margin-top: 36px;
  height: 64px;
  justify-content: flex-end;
}

header #title {
  color: black;
  text-decoration: none;
  margin: 0px;
  width: 100%;
  font-size: 48px;
  font-weight: bold;
  color: #2a81f9;
}

.header-btn {
  text-decoration: none;
  font-size: 16px;
  margin-left: 5px;
  margin-right: 5px;
}

footer {
  margin-top: 20px;
  text-align: center;
}

.hidden {
  visibility: hidden;
}

#error-box {
  color: red;
  visibility: hidden;
}

#error-box::before {
  content: "Error: ";
}

.gallery-title {
  font-size: 24px;
  font-weight: bold;
  margin-bottom: 15px;
}

.gallery-link {
  width: 100%;
  text-align: left;
  font-size: 18px;
  margin-bottom: 10px;
}