:root {
  --color-deep-blue: #020826;
  --color-galaxy-purple: #47407A;
  --color-matrix-green: #00E8C4;
  --color-gold-dust: #E6D0AA;
  --color-soft-light: #A0B9C9;
}

body {
  font-family: 'Montserrat', 'Segoe UI', sans-serif;
  background-color: var(--color-deep-blue);
  color: var(--color-soft-light);
  margin: 0;
  padding: 30px 20px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

h1 {
  color: var(--color-matrix-green);
  font-weight: 700;
  margin-bottom: 20px;
  border-bottom: 2px solid var(--color-galaxy-purple);
  padding-bottom: 10px;
}

.board {
  display: grid;
  grid-template-columns: repeat(4, 80px);
  grid-template-rows: repeat(4, 80px);
  gap: 15px;
  justify-content: center;
  margin: 20px auto;
  background-color: rgba(71, 64, 122, 0.1);
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 0 15px rgba(0, 232, 196, 0.3);
  border: 1px solid var(--color-galaxy-purple);
  user-select: none;
}

.tile {
  width: 80px;
  height: 80px;
  background-color: var(--color-galaxy-purple);
  color: var(--color-gold-dust);
  font-weight: bold;
  font-size: 36px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(71, 64, 122, 0.7);
  transition: background-color 0.3s ease, color 0.3s ease;
  border: 2px solid transparent;
}

.tile.flipped, .tile.matched {
  background-color: var(--color-matrix-green);
  color: var(--color-deep-blue);
  cursor: default;
  border-color: var(--color-matrix-green);
  animation: pulseGlow 2s infinite;
}

.tile.hidden {
  background-color: var(--color-galaxy-purple);
  color: transparent;
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 8px var(--color-matrix-green); }
  50% { box-shadow: 0 0 20px var(--color-matrix-green); }
}

#score {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-gold-dust);
  margin-bottom: 5px;
}

#timer {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-gold-dust);
  margin-bottom: 15px;
}

#message {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 24px;
  font-weight: 700;
  color: var(--color-gold-dust);
  background: rgba(0, 0, 0, 0.75);
  padding: 20px 30px;
  border-radius: 12px;
  box-shadow: 0 0 20px var(--color-gold-dust);
  z-index: 1000;
  text-align: center;
  display: none;
}

#message.show {
  display: block;
}

#main {
  display: flex;
  max-width: 900px;
  margin: 0 auto;
  gap: 20px;
  font-family: 'Montserrat', sans-serif;
  color: var(--color-soft-light);
}

#left-panel {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  max-width: 300px;
  margin-right: 40px;
  margin-top: 30px;	
}

#nameInputContainer {
  background: rgba(7, 40, 90, 0.8);
  padding: 15px;
  border-radius: 8px;
  text-align: center;
  margin-bottom: 15px;
}

#nameInput {
  font-size: 18px;
  padding: 6px;
  width: 100%;
  text-transform: uppercase;
}

#nameSubmit {
  margin-top: 10px;
  padding: 8px 12px;
  font-weight: 600;
  cursor: pointer;
  border-radius: 6px;
  border: none;
  background-color: var(--color-matrix-green);
  color: var(--color-deep-blue);
}

#nameError {
  color: #f88;
  margin-top: 8px;
  display: none;
}

#leaderboard {
  flex: 0 0 auto;
  background: rgba(7, 40, 90, 0.8);
  padding: 12px 15px;
  border-radius: 8px;
  font-size: 15px;
  color: var(--color-soft-light);
  font-family: 'Montserrat', sans-serif;
  width: 100%;
  overflow: visible;
  max-height: none;
  height: auto;
}

#leaderboard h2 {
  margin: 0 0 6px 0;
  color: var(--color-gold-dust);
  font-size: 17px;
  text-align: center;
}

#leaderboard ol {
  margin: 0;
  padding: 0 0 0 20px;
  list-style-position: inside;
  line-height: 1.2;
}

#leaderboard li {
  margin: 2px 0;
  padding: 0;
}

#game-container {
  flex: 1.5;
  text-align: center;
  color: var(--color-soft-light);
}

#startBtn {
  font-size: 20px;
  padding: 12px 28px;
  border-radius: 8px;
  border: none;
  background-color: var(--color-matrix-green);
  color: var(--color-deep-blue);
  cursor: pointer;
  font-weight: 600;
  user-select: none;
}

#startBtn:disabled {
  background-color: #999;
  cursor: not-allowed;
}