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

body,
html {
  height: 100%;
  font-family: Arial, sans-serif;
  background-color: #1e1e2f;
  color: #f8f8f2;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

.welcome-screen {
  position: absolute;
  z-index: 10;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 20px;
  align-items: center;
  justify-content: center;
}

.welcome-screen h1 {
  font-size: 2.5rem;
  color: #ffcf56;
  text-shadow: 0 0 10px #ffcf56, 0 0 20px #ffaa00;
  animation: glow 2s ease-in-out infinite alternate;
}

.tagline {
  font-size: 1.1rem;
  color: #a8dadc;
  margin-top: -10px;
}

#welcome-btn {
  background-color: #00b4d8;
  color: white;
  padding: 10px 20px;
  font-size: 1.2rem;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

#welcome-btn:hover {
  background-color: #0077b6;
}

.game-container {
  display: none;
  text-align: center;
  background: #2b2d42;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 4px 15px rgba(0, 255, 255, 0.3);
  z-index: 5;
}

.scoreboard {
  display: flex;
  justify-content: space-around;
  margin-bottom: 10px;
  color: #a8dadc;
  font-weight: bold;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-gap: 5px;
  margin: 15px 0;
}

.cell {
  width: 80px;
  height: 80px;
  background: #edf2f4;
  font-size: 36px;
  font-weight: bold;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.3s, transform 0.3s;
}

.cell.X {
  color: #005f56;
}

.cell.O {
  color: #f72585;
}

.cell.win {
  background-color: #caffbf;
  box-shadow: 0 0 15px #00ffab;
  transform: scale(1.1);
}

#reset-btn {
  background-color: #00b4d8;
  color: white;
  padding: 10px 20px;
  border: none;
  border-radius: 5px;
  font-size: 1rem;
  cursor: pointer;
}

#reset-btn:hover {
  background-color: #0077b6;
}

#status {
  font-size: 20px;
  font-weight: bold;
  color: #ffcf56;
  text-shadow: 0 0 5px #ffcf56;
  margin-top: 10px;
}

.background {
  position: fixed;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  overflow: hidden;
  z-index: -1;
}

.shape {
  position: absolute;
  opacity: 0.5;
}

.square {
  width: 50px;
  height: 50px;
  background: #ff6b6b;
  animation: floatUp 12s ease-in-out infinite;
  top: 80%;
  left: 10%;
}

.circle {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: #00f5d4;
  animation: floatSide 10s ease-in-out infinite;
  top: 5%;
  left: 5%;
}

.triangle {
  width: 0;
  height: 0;
  border-left: 25px solid transparent;
  border-right: 25px solid transparent;
  border-bottom: 50px solid #f72585;
  animation: rotateMove 14s linear infinite;
  top: 50%;
  left: 25%;
}

.rectangle {
  width: 100px;
  height: 40px;
  background: #7209b7;
  border-radius: 10px;
  animation: horizontalWave 15s ease-in-out infinite;
  top: 30%;
  right: 5%;
}

.diamond {
  width: 50px;
  height: 50px;
  background: #ffd6a5;
  transform: rotate(45deg);
  animation: floatBounce 18s ease-in-out infinite;
  left: 40%;
  top: 20%;
}

.star {
  width: 0;
  height: 0;
  background: transparent;
  border-left: 30px solid transparent;
  border-right: 30px solid transparent;
  border-bottom: 60px solid #ffb703;
  animation: horizontalWave 10s ease-in-out infinite;
  top: 70%;
  right: 30%;
}

@keyframes glow {
  from {
    text-shadow: 0 0 10px #ffcf56, 0 0 20px #ffaa00;
  }
  to {
    text-shadow: 0 0 20px #ffaa00, 0 0 30px #ffcf56;
  }
}

@keyframes floatUp {
  0% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-100px);
  }
  100% {
    transform: translateY(0);
  }
}

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

@keyframes rotateMove {
  0% {
    transform: rotate(0deg) translateY(0);
  }
  50% {
    transform: rotate(180deg) translateY(-50px);
  }
  100% {
    transform: rotate(360deg) translateY(0);
  }
}

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

@keyframes floatBounce {
  0% {
    transform: rotate(45deg) translateY(0);
  }
  50% {
    transform: rotate(45deg) translateY(-60px);
  }
  100% {
    transform: rotate(45deg) translateY(0);
  }
}

@keyframes twinkle {
  0%,
  100% {
    opacity: 0.3;
  }
  50% {
    opacity: 0.7;
  }
}