:root {
    --squareSize: 15vh;
    --borderSize: 2px;
}

body {
    display: flex;
    align-items: center;
    flex-direction: column;
}

h1 {
    margin: 10vh auto 10vh auto;
}

a {
    font-size: 3vh;
    
    text-align: center;
    
}

#board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    width: min-content;
    position: relative;
}

.spaces {
    background-color: white;
    height: var(--squareSize);
    width: var(--squareSize);
    display: grid;
    place-content: center;
}

.spaces:nth-child(1), 
.spaces:nth-child(2),
.spaces:nth-child(3),
.spaces:nth-child(4),
.spaces:nth-child(5),
.spaces:nth-child(6) {
    border-bottom: var(--borderSize) black solid;
}

.spaces:nth-child(1),
.spaces:nth-child(2),
.spaces:nth-child(4),
.spaces:nth-child(5),
.spaces:nth-child(7),
.spaces:nth-child(8) {
    border-right: var(--borderSize) black solid;
}

.spaces:nth-child(2),
.spaces:nth-child(3),
.spaces:nth-child(5),
.spaces:nth-child(6),
.spaces:nth-child(8),
.spaces:nth-child(9) {
    border-left: var(--borderSize) black solid;
}

.spaces:nth-child(4),
.spaces:nth-child(5),
.spaces:nth-child(6),
.spaces:nth-child(7),
.spaces:nth-child(8),
.spaces:nth-child(9) {
    border-top: var(--borderSize) black solid;
}

.circle {
    border-radius: 50%;
    background-color: blue;
    height: calc(var(--squareSize) - 4vh);
    width: calc(var(--squareSize) - 4vh);
    display: grid;
    place-content: center;
}

.circle div {
    border-radius: inherit;
    background-color: #fff;
    height: calc(var(--squareSize) - 6vh);
    width: calc(var(--squareSize) - 6vh);
}

.cross {
    height: calc(var(--squareSize) - 2vh);
    width: calc(var(--squareSize) - 2vh);
    display: grid;
    place-content: center;
    position: relative;
}

.cross div {
    height: 1vh;
    width: calc(var(--squareSize) - 2vh);
    background-color: red;
    position: absolute;
    top: calc(50% - 0.5vh);
}

.cross div:nth-child(1) {
    transform: rotate(45deg);
}

.cross div:nth-child(2) {
    transform: rotate(-45deg);
    
}

#screen {
    position: absolute;
    right: 0;
    left: 0;
    top: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.50);
    color: white;
    display: grid;
    place-content: center;
    font-size: calc(var(--squareSize) - 4vh);
    border-radius: calc(var(--squareSize) / 2);
}

#choosePlayerPiece,
#chooseFirstPlayer,
#menu {
    display: flex;
    margin-top: 7vh;
}

#menu a {
    margin: 2vh;
}

#choosePlayerPiece button {
    background: none;
    border: none;
}

#chooseFirstPlayer button {
    margin: 1vh;
    height: calc(var(--squareSize) - 4vh);
    width: calc(var(--squareSize) - 4vh);
    background: none;
    border: none;
}

#github {
    position: fixed;
    bottom: 1vh;
}