body {
  background: #eef2f3;
  font-family: Arial, sans-serif;
  text-align: center;
  color: #222;
  margin: 0;
  padding: 0;
}

h1 {
  margin-top: 2rem;
  color: #3498db;
  font-size: 2.5rem;
  line-height: 1.2;
}

/* Board responsive styles */
#board {
  display: grid;
  grid-template-columns: repeat(3, minmax(60px, 22vw));
  grid-template-rows: repeat(3, minmax(60px, 22vw));
  gap: 0.8em;
  justify-content: center;
  margin: 2rem auto 1.5rem auto;
  max-width: 95vw;
}

/* Cell responsive styles */
.cell {
  width: 100%;
  height: 100%;
  background: #fff;
  border-radius: 0.5em;
  box-shadow: 0 2px 8px #bbb;
  font-size: 8em;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.cell:hover, .cell:focus {
  background: #f1fafe;
}

#status {
  font-size: 1.15em;
  min-height: 2em;
  margin-bottom: 1em;
  word-break: break-word;
}

#restart-btn {
  background: #3498db;
  color: #fff;
  font-size: 1em;
  border: none;
  border-radius: 0.7em;
  padding: 0.7em 2em;
  cursor: pointer;
  transition: background 0.2s;
}

#restart-btn:hover,
#restart-btn:focus {
  background: #297fb8;
}

/* SMALL DEVICES (phones) */
@media (max-width: 480px) {
  h1 {
    font-size: 1.5rem;
    margin-top: 1rem;
  }
  #board {
    grid-template-columns: repeat(3, minmax(40px, 28vw));
    grid-template-rows: repeat(3, minmax(40px, 28vw));
    gap: 0.5em;
    margin: 1rem auto;
  }
  .cell {
    font-size: 10em;
    border-radius: 0.35em;
  }
  #status {
    font-size: 1em;
    min-height: 1.2em;
    margin-bottom: 0.7em;
  }
  #restart-btn {
    font-size: 0.95em;
    padding: 0.6em 1.2em;
  }
}

/* TABLETS */
@media (max-width: 768px) {
  h1 {
    font-size: 2rem;
  }
  #board {
    grid-template-columns: repeat(3, minmax(50px, 22vw));
    grid-template-rows: repeat(3, minmax(50px, 22vw));
  }
  .cell {
    font-size: 10em;
  }
}

/* BIG SCREENS */
@media (min-width: 1200px) {
  #board {
    grid-template-columns: repeat(3, 110px);
    grid-template-rows: repeat(3, 110px);
    gap: 1em;
  }
  .cell {
    font-size: 3em;
  }
}
/* Controles de partida y marcador */
#controls {
  margin: 1rem auto 0.5rem auto;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
#controls select#first-player {
  font-size: 1em;
  padding: 6px 10px;
  border-radius: 8px;
  border: 1px solid #ddd;
}
#score {
  margin: 0.6rem auto 0.4rem auto;
  font-size: 1em;
  color: #444;
}

/* Ajustes para botones-celda (accesibilidad) */
.cell {
  border: none;
  outline: none;
}
.cell:focus-visible {
  box-shadow: 0 0 0 4px rgba(52, 152, 219, 0.35);
}

/* Resaltado de combinación ganadora */
.win {
  background: #eaf7ff;
  box-shadow: 0 0 0 2px rgba(61, 90, 254, 0.25), 0 2px 10px rgba(61, 90, 254, 0.16);
}

@media (prefers-color-scheme: dark) {
  #controls select#first-player {
    background: #20233a;
    color: #eaeaf0;
    border-color: #2c3252;
  }
  #score {
    color: #a0a3b0;
  }
  .cell:focus-visible {
    box-shadow: 0 0 0 4px rgba(61, 90, 254, 0.35);
  }
  .win {
    background: #172441;
    box-shadow: 0 0 0 2px rgba(61, 90, 254, 0.35), 0 2px 12px rgba(61, 90, 254, 0.22);
  }
}