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

body {
  font-family: Arial, sans-serif;
  background-color: #f0f0f0;
}

.container {
  max-width: calc(100vh - 85px);
  margin: 5px auto;
  padding: 5px;
  background-color: #fff;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
  text-align: center;
}

h1 {
  font-size: 40px;
  margin-bottom: 0;
}

#board {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  grid-gap: 1px;
}

.row {
  display: flex;
  justify-content: space-between;
}

.cell {
  aspect-ratio: 1 / 1;
  border: 1px solid #ccc;
  cursor: pointer;
  font-size: xx-large;
  font-weight: bold;
  display: flex;
  justify-content: center;
  align-items: center;
  background-position: center;
  background-repeat: no-repeat;
  background-size: 80%;
}

.cell:hover {
  background-color: #f0f0f0;
}

.X {
  background-image: url("x-solid.svg");
}

.O {
  background-image: url("o-solid.svg");
}

.X-turn {
  color: #e74c3c;
}

.O-turn {
  color: #3498db;
}

#message {
  font-size: 25px;
  margin-top: 20px;
  margin-bottom: 20px;
}

.btn-game {
  background-color: #3498db;
  border: none;
  color: #fff;
  padding: 10px 20px;
  font-size: 16px;
  font-weight: bold;
  cursor: pointer;
  transition: background-color 0.3s;
  width: 100%;
}

.btn-game:hover {
  background-color: #2980b9;
}

.actions {
  position: fixed;
  right: 0;
  height: 100%;
  background-color: #fff;
  padding: 10px 20px;
  width: 250px;
}

.ratio-container {
  margin-bottom: 20px;
}

.board-size {
  margin-bottom: 20px;
}

.credit {
  position: fixed;
  bottom: 5px;
}