style.css

body {
  background: rgb(28, 27, 34);
  color: whitesmoke;
  width: 100vw;
  height: 100vh;
  display: grid;
  justify-content: center;
  align-content: center;
}
.opponentPicking {
  display: grid;
  justify-items: center;
}
.oponentbtn {
  display: grid;
  grid-template-columns: auto auto;
  gap: 20px;
}
.hide {
  display: none;
}
.alert {
  border: 2px solid red;
}
.playersNames {
  display: none;
  gap: 25px;
}
form.active {
  display: grid;
  gap: 25px;
  grid-template-columns: 154px 155px;
}
input:invalid {
  border: 1px solid red;
}
.error {
  width: 100%;
  padding: 0;
  font-size: 80%;
  color: white;
  background-color: #900;
  border-radius: 0 0 5px 5px;
  box-sizing: border-box;
  position: relative;
  left: 91px;
}
.gameboard {
  display: grid;
  grid-template-columns: auto auto auto;
}
.gameboard > div {
  display: none;
  width: 111px;
  height: 111px;
  border: 1px solid blue;
  padding: 0;
  justify-content: center;
  align-content: center;
  font-size: 4em;
}
.scoore {
  display: grid;
  grid-template-columns: auto auto;
  justify-content: space-between;
  gap: 24px;
}
.winner {
  position: absolute;
  top: 5%;
  left: 41%;
  color: #900;
}
.restart {
  display: none;
  justify-self: center;
}