body {
  background: linear-gradient(132deg, #000000,#00ff00, #0000ff,#e60073,#ff0000,#ffffff);
  background-size: 400% 400%;
  animation: BackgroundGradient 15s ease infinite;
}

h1 {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translateX(-50%) translateY(-50%);
  font-family: Open Sans, sans-serif;
  color: #fff;
  font-weight: 400;
  text-transform: uppercase;
  text-align: center;
  font-size: 2em;
  padding: 5px;
}
@keyframes BackgroundGradient {
  0% {background-position: 0% 50%;}
  50% {background-position: 100% 50%;}
  100% {background-position: 0% 50%;}
}

/* The gigantic rave sheet */
#sheet {
  position: relative;
  width: 6000px;
  height: 4000px;
}

/* Neon poster blocks */
.poster {
  position: absolute;
  width: 320px;
  height: 200px;
  background: rgba(255, 0, 150, 0.15);
  border: 2px solid #ff00ff;
  box-shadow: 0 0 25px #ff00ff, 0 0 50px #ff00ff inset;
  overflow: hidden;
  animation: neon-flicker 2s infinite;
}

.poster iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* Neon flicker animation */
@keyframes neon-flicker {
  0%, 18%, 22%, 25%, 53%, 57%, 100% {
    box-shadow: 0 0 25px #ff00ff, 0 0 50px #ff00ff inset;
    border-color: #ff00ff;
  }
  20%, 24%, 55% {
    box-shadow: 0 0 5px #ff00ff;
    border-color: #770077;
  }
}

/* Glitch effect on posters */
.poster::before,
.poster::after {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(255,0,255,0.1);
  mix-blend-mode: screen;
  pointer-events: none;
  animation: glitch 3s infinite;
}

.poster::after {
  background: rgba(0,255,255,0.15);
  animation: glitch 2.5s infinite reverse;
}

@keyframes glitch {
  0% { transform: translate(0,0); opacity: 0; }
  10% { transform: translate(-5px, 3px) skew(5deg); opacity: 1; }
  20% { transform: translate(5px,-3px) skew(-3deg); }
  30% { transform: translate(-3px, 2px); opacity: 0.6; }
  40% { transform: translate(0,0); opacity: 0; }
  100% { transform: translate(0,0); opacity: 0; }
}

/* Graffiti text with flicker & glitch */
.graffiti {
  position: absolute;
  font-size: 48px;
  font-weight: bold;
  color: #0ff;
  text-shadow: 0 0 15px #0ff, 0 0 25px #f0f;
  transform: rotate(-10deg);
  animation: graffiti-flicker 4s infinite, graffiti-glitch 2s infinite;
}

@keyframes graffiti-flicker {
  0%, 19%, 21%, 23%, 60%, 100% {
    color: #0ff;
    text-shadow: 0 0 15px #0ff, 0 0 25px #f0f;
  }
  20%, 22%, 61% {
    color: #044;
    text-shadow: none;
  }
}

@keyframes graffiti-glitch {
  0% { transform: translate(0,0) rotate(-10deg); }
  10% { transform: translate(-2px,1px) rotate(-10deg); }
  20% { transform: translate(3px,-1px) rotate(-10deg); }
  30% { transform: translate(-1px,2px) rotate(-10deg); }
  40% { transform: translate(0,0) rotate(-10deg); }
  100% { transform: translate(0,0) rotate(-10deg); }
}

/* Secret hotspots */
.secret {
  position: absolute;
  width: 40px;
  height: 40px;
  background: radial-gradient(circle, #ff0, #f00);
  border-radius: 50%;
  box-shadow: 0 0 20px #ff0;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(1); box-shadow: 0 0 10px #ff0, 0 0 20px #f00; }
  50% { transform: scale(1.2); box-shadow: 0 0 20px #ff0, 0 0 40px #f00; }
  100% { transform: scale(1); box-shadow: 0 0 10px #ff0, 0 0 20px #f00; }
}

.secret-message {
  display: none;
  position: absolute;
  top: -80px;
  left: -50px;
  background: rgba(0, 0, 0, 0.85);
  color: #0f0;
  padding: 10px;
  border: 1px solid #0f0;
  box-shadow: 0 0 15px #0f0;
  font-size: 14px;
  white-space: nowrap;
}

.secret:hover .secret-message {
  display: block;
}