body {
  background: url("test sparkle.gif");
  color: #fff;
  margin: 0;
  padding: 0;
  background-color: #000;
}
body {
  font-family: 'OCR A Std', monospace;
  background-color: black;
  color: limegreen;
}


.banner {
  background: limegreen;
  color: black;
  font-size: 28px;
  padding: 20px;
  text-align: center;
  border: 5px solid blue;
  animation: blink 1s infinite;
}
@keyframes blink {
  50% { opacity: 0; }
}


.sidebar {
  background: black;
  padding: 20px;
  width: 200px;
  float: left;
  border: 3px solid limegreen;
}
.sidebar a {
  display: block;
  background: blue;
  color: white;
  padding: 10px;
  margin-bottom: 10px;
  text-decoration: none;
  font-weight: bold;
  border: 2px solid limegreen;
}
.sidebar a:hover {
  background: limegreen;
  color: black;
}


.content {
  margin-left: 220px;
  padding: 20px;
}

.section-box {
  background: #111;
  border: 3px solid limegreen;
  padding: 20px;
  margin-bottom: 20px;
  border-radius: 8px;
  color: white;
}


.blinking {
  animation: blink 1s infinite;
  color: blue;
  font-size: 24px;
}
.rainbow-text {
  font-size: 26px;
  font-weight: bold;
  background: linear-gradient(to right, limegreen, white, blue, black);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.marquee {
  background: blue;
  color: white;
  font-weight: bold;
  padding: 10px;
  border: 3px solid limegreen;
}


.popup {
  display: none;
  position: fixed;
  z-index: 999;
  left: 0; top: 0;
  width: 100%; height: 100%;
  background-color: rgba(0,0,0,0.8);
}
.popup:target {
  display: block;
}
.popup-content {
  background: black;
  margin: 10% auto;
  padding: 20px;
  border: 3px solid limegreen;
  width: 80%;
  max-width: 500px;
  color: white;
  border-radius: 8px;
}
.close {
  float: right;
  font-size: 28px;
  text-decoration: none;
  color: limegreen;
}

.gif-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
  margin: 15px 0 20px 0;
  padding: 10px;
  background: #000;
  border: 3px solid limegreen;
}

.gif-grid img {
  width: 100%;
  height: auto;
  border: 2px solid blue;
  background: black;
}
.close:hover {
  color: blue;
}