body {
  background: #0a0a0a;
  color: #fff;
  font-family: 'Courier New', monospace;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  overflow: hidden;
}
body::before {
  content: '';
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: repeating-linear-gradient(
    to bottom,
    rgba(255,255,255,0.02) 0,
    rgba(255,255,255,0.02) 1px,
    transparent 2px
  );
  pointer-events: none;
  z-index: 0;
}
.overlay {
  position: absolute;
  background: rgba(0,0,0,0.85);
  border: 2px solid cyan;
  border-radius: 10px;
  padding: 20px 25px;
  box-shadow: 0 0 15px cyan;
  text-align: center;
  z-index: 10;
}
.overlay h2 {
  margin: 0 0 15px 0;
  font-weight: normal;
  font-size: 1.5rem;
  color: cyan;
  text-shadow: 0 0 8px cyan;
}
label {
  display: block;
  margin-bottom: 12px;
  font-size: 14px;
  color: #0ff;
  user-select: none;
}
select, button {
  background: black;
  border: 1px solid cyan;
  color: cyan;
  padding: 8px 12px;
  font-family: inherit;
  font-size: 14px;
  border-radius: 6px;
  transition: 0.3s;
}
select:hover, button:hover {
  background: cyan;
  color: black;
  cursor: pointer;
}
#board {
  display: grid;
  grid-template-columns: repeat(3, 80px);
  grid-template-rows: repeat(3, 80px);
  gap: 5px;
  z-index: 5;
}
.cell {
  background: #111;
  border: 2px solid #0ff;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 36px;
  font-weight: bold;
  cursor: pointer;
  color: cyan;
  text-shadow: 0 0 5px cyan, 0 0 10px cyan;
  user-select: none;
  transition: background 0.3s, color 0.3s;
}
.cell.taken {
  cursor: not-allowed;
}
.cell.X {
  color: #ff2aad;
  text-shadow: 0 0 10px #ff2aad, 0 0 20px #ff2aad;
}
.cell.O {
  color: #00fff7;
  text-shadow: 0 0 10px #00fff7, 0 0 20px #00fff7;
}
.win {
  animation: pulse 1s infinite alternate;
}
@keyframes pulse {
  0% {
    text-shadow:
      0 0 15px magenta,
      0 0 30px magenta,
      0 0 40px cyan,
      0 0 80px cyan;
    color: magenta;
  }
  100% {
    text-shadow:
      0 0 30px cyan,
      0 0 60px cyan,
      0 0 70px magenta,
      0 0 140px magenta;
    color: cyan;
  }
}
#restartBtn {
  margin-top: 15px;
  background: black;
  border: 1.5px solid cyan;
  color: cyan;
  padding: 8px 18px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  user-select: none;
}
#restartBtn:hover {
  background: cyan;
  color: black;
  cursor: pointer;
}
/* RESULT OVERLAY */
#resultOverlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(10, 10, 10, 0.9);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 20;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.4s ease;
  user-select: none;
  flex-direction: column;
  overflow: hidden;
}
#resultOverlay.visible {
  visibility: visible;
  opacity: 1;
}
#resultOverlay h1 {
  color: #ff2aad;
  font-size: 3rem;
  text-shadow:
    0 0 10px #ff2aad,
    0 0 20px #ff2aad,
    0 0 40px #00fff7,
    0 0 80px #00fff7;
  animation: pulse 1s infinite alternate;
  margin-bottom: 20px;
  position: relative;
}
#resultOverlay h1.glitch {
  color: #00fff7;
  animation: glitch 1.5s infinite;
}
#resultOverlay h1.glitch::before,
#resultOverlay h1.glitch::after {
  content: attr(data-text);
  position: absolute;
  left: 0; top: 0;
  width: 100%; height: 100%;
  opacity: 0.8;
  clip: rect(0, 900px, 0, 0);
}
#resultOverlay h1.glitch::before {
  left: 2px;
  text-shadow: -2px 0 red;
  animation: glitchTop 1.5s infinite;
}
#resultOverlay h1.glitch::after {
  left: -2px;
  text-shadow: -2px 0 blue;
  animation: glitchBottom 1.5s infinite;
}
#resultOverlay .message {
  color: cyan;
  font-size: 1.5rem;
  margin-bottom: 30px;
  text-shadow: 0 0 8px cyan;
  animation: flicker 2s infinite alternate;
}
#resultOverlay button {
  background: black;
  border: 2px solid cyan;
  padding: 12px 25px;
  font-size: 18px;
  font-weight: 700;
  border-radius: 12px;
  color: cyan;
  cursor: pointer;
  transition: 0.3s;
  user-select: none;
}
#resultOverlay button:hover {
  background: cyan;
  color: black;
}
/* SCANLINE OVERLAY */
#scanlineOverlay {
  pointer-events: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: repeating-linear-gradient(
    to bottom,
    rgba(0, 255, 255, 0.05) 0,
    rgba(0, 255, 255, 0.05) 1px,
    transparent 2px
  );
  animation: scanlineMove 3s linear infinite;
  z-index: 19;
  opacity: 0;
  transition: opacity 0.5s ease;
}
#scanlineOverlay.visible {
  opacity: 1;
}
@keyframes flicker {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}
@keyframes glitch {
  0% {
    clip: rect(0, 9999px, 0, 0);
    transform: translate(0);
  }
  20% {
    clip: rect(0, 9999px, 15px, 0);
    transform: translate(-2px, -2px);
  }
  40% {
    clip: rect(0, 9999px, 5px, 0);
    transform: translate(2px, 2px);
  }
  60% {
    clip: rect(0, 9999px, 12px, 0);
    transform: translate(-2px, 2px);
  }
  80% {
    clip: rect(0, 9999px, 7px, 0);
    transform: translate(2px, -2px);
  }
  100% {
    clip: rect(0, 9999px, 0, 0);
    transform: translate(0);
  }
}
@keyframes glitchTop {
  0% {
    clip: rect(0, 9999px, 10px, 0);
    transform: translate(2px, -2px);
  }
  50% {
    clip: rect(0, 9999px, 15px, 0);
    transform: translate(-2px, 2px);
  }
  100% {
    clip: rect(0, 9999px, 10px, 0);
    transform: translate(2px, -2px);
  }
}
@keyframes glitchBottom {
  0% {
    clip: rect(5px, 9999px, 20px, 0);
    transform: translate(-2px, 2px);
  }
  50% {
    clip: rect(0, 9999px, 12px, 0);
    transform: translate(2px, -2px);
  }
  100% {
    clip: rect(5px, 9999px, 20px, 0);
    transform: translate(-2px, 2px);
  }
}
@keyframes scanlineMove {
  0% { background-position: 0 0; }
  100% { background-position: 0 100%; }
}