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

body{
  height:100vh;
  overflow:hidden;
  background:#000;
  font-family:Arial, Helvetica, sans-serif;
}

/* =========================
   WORLD CONTAINER
========================= */
.world{
  position:relative;
  width:100%;
  height:100vh;
  overflow:hidden;
}

/* =========================
   SKY (MULTI-LAYER LIGHT)
========================= */
.sky{
  position:absolute;
  width:100%;
  height:100%;
  background:
    radial-gradient(circle at 20% 30%, #ff00ff33, transparent 40%),
    radial-gradient(circle at 80% 40%, #00ffff33, transparent 45%),
    radial-gradient(circle at 50% 70%, #7700ff22, transparent 60%),
    linear-gradient(180deg, #02020a, #000);
  animation:skyShift 10s infinite alternate;
}

@keyframes skyShift{
  0%{filter:hue-rotate(0deg) brightness(1);}
  100%{filter:hue-rotate(30deg) brightness(1.2);}
}

/* =========================
   CITY LAYERS (DEPTH PARALLAX)
========================= */
.city{
  position:absolute;
  bottom:0;
  width:120%;
  left:-10%;
  height:60%;
  background:
    repeating-linear-gradient(
      90deg,
      #050505 0px,
      #050505 25px,
      #0a0a0a 25px,
      #0a0a0a 50px
    );
  clip-path: polygon(
    0% 100%, 0% 60%, 5% 55%, 10% 65%, 15% 50%, 20% 70%,
    25% 40%, 30% 75%, 35% 45%, 40% 70%, 45% 35%, 50% 80%,
    55% 50%, 60% 75%, 65% 40%, 70% 70%, 75% 45%, 80% 65%,
    85% 50%, 90% 70%, 95% 55%, 100% 60%, 100% 100%
  );
}

/* BACK LAYER */
.city-back{
  transform:scale(1.2);
  opacity:0.4;
  filter:blur(2px) drop-shadow(0 0 20px #ff00ff);
  animation:moveBack 12s linear infinite;
}

/* MID LAYER */
.city-mid{
  transform:scale(1.1);
  opacity:0.6;
  filter:drop-shadow(0 0 30px #00ffff);
  animation:moveMid 8s linear infinite;
}

/* FRONT LAYER */
.city-front{
  opacity:0.9;
  filter:drop-shadow(0 0 40px #ff00ff);
  animation:moveFront 5s linear infinite;
}

@keyframes moveBack{
  0%{transform:translateX(0) scale(1.2);}
  100%{transform:translateX(-20px) scale(1.2);}
}

@keyframes moveMid{
  0%{transform:translateX(0) scale(1.1);}
  100%{transform:translateX(20px) scale(1.1);}
}

@keyframes moveFront{
  0%{transform:translateX(0);}
  100%{transform:translateX(-30px);}
}

/* =========================
   GLITCH TITLE
========================= */
.hud{
  position:absolute;
  top:18%;
  width:100%;
  text-align:center;
  z-index:10;
}

.glitch-title{
  font-size:6rem;
  color:white;
  letter-spacing:12px;
  text-transform:uppercase;
  animation:glitch 0.4s infinite;
  text-shadow:
    0 0 10px #ff00ff,
    0 0 30px #00ffff,
    0 0 60px #ff00ff;
}

@keyframes glitch{
  0%{transform:translate(0);}
  20%{transform:translate(-3px,2px);}
  40%{transform:translate(3px,-2px);}
  60%{transform:translate(-2px,1px);}
  80%{transform:translate(2px,-1px);}
  100%{transform:translate(0);}
}

.subtitle{
  color:#ffffffaa;
  margin-top:10px;
  letter-spacing:4px;
}

/* =========================
   BUTTON (HOLOGRAM STYLE)
========================= */
.button{
  margin-top:40px;
  display:inline-block;
  padding:15px 40px;
  border:1px solid #00ffff;
  color:#00ffff;
  letter-spacing:3px;
  cursor:pointer;
  transition:0.3s;
  text-shadow:0 0 10px #00ffff;
  box-shadow:0 0 20px #00ffff33;
}

.button:hover{
  background:#00ffff22;
  transform:scale(1.1);
  box-shadow:0 0 40px #00ffff;
}

/* =========================
   RAIN SYSTEM (DIGITAL CYBER RAIN)
========================= */
.rain{
  position:absolute;
  width:100%;
  height:100%;
  background-image:
    linear-gradient(#00ffff 1px, transparent 1px),
    linear-gradient(#ff00ff 1px, transparent 1px);
  background-size:2px 40px;
  opacity:0.15;
  animation:rain 0.8s linear infinite;
}

@keyframes rain{
  0%{transform:translateY(0);}
  100%{transform:translateY(-100px);}
}

/* =========================
   FOG (DEPTH ATMOSPHERE)
========================= */
.fog{
  position:absolute;
  width:100%;
  height:100%;
  background:
    radial-gradient(circle at center, transparent 40%, #000 90%),
    linear-gradient(90deg, #ff00ff11, #00ffff11);
  animation:fogMove 6s infinite alternate;
}

@keyframes fogMove{
  0%{transform:translateX(-50px);}
  100%{transform:translateX(50px);}
}

/* =========================
   SCANLINES + DISTORTION
========================= */
.scanlines{
  position:absolute;
  width:100%;
  height:100%;
  background:repeating-linear-gradient(
    to bottom,
    rgba(255,255,255,0.04),
    transparent 2px,
    transparent 4px
  );
  animation:scan 1s linear infinite;
  mix-blend-mode:overlay;
}

@keyframes scan{
  0%{transform:translateY(0);}
  100%{transform:translateY(10px);}
}