@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800;900&display=swap");

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Poppins", sans-serif;
}

:root{
    --cell-size: 100px;
    --mark-size: calc(var(--cell-size) *.9);
}

.container{
    display: flex;
    width: 100%;
    min-height: 100vh;
    background: linear-gradient(90deg, rgba(22,160,133,1) 0%, rgba(41,128,185,1) 100%);
    padding: 10px;
}

.board{
    width: 500px;
    height: 500px;
    display: grid;
    margin: auto;
    justify-content: center;
    align-content: center;
    justify-items: center;
    align-items: center;
    background-color: #fff;
    grid-template-columns: repeat(3, auto);
    border-radius: 10px;
}

.cell{
    width: var(--cell-size);
    height: var(--cell-size);
    border: 2px solid black;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    cursor: pointer;
}

.cell:first-child,
.cell:nth-child(2),
.cell:nth-child(3) {
    border-top: none;
}
.cell:nth-child(3n+1){
    border-left: none;
}
.cell:nth-child(3n+3){
    border-right: none;
}
.cell:last-child,
.cell:nth-child(8),
.cell:nth-child(7) {
    border-bottom: none;
}

.cell.x, .cell.circle{
    cursor: not-allowed;
}

.cell.x::before,
.cell.x::after,
.cell.circle::before{
    background-color: black;
}

.board.x .cell:not(.x):not(.circle):hover::before,
.board.x .cell:not(.x):not(.circle):hover::after,
.board.circle .cell:not(.x):not(.circle):hover::before{
    background-color: lightgray;
}

.cell.x::before,
.cell.x::after,
.board.x .cell:not(.x):not(.circle):hover::before,
.board.x .cell:not(.x):not(.circle):hover::after{
    content: '';
    position: absolute;
    width: calc(var(--mark-size) *.15);
    height: calc(var(--mark-size));
}
.cell.x::before,
.board.x .cell:not(.x):not(.circle):hover::before{
    transform: rotate(45deg);
}
.cell.x::after,
.board.x .cell:not(.x):not(.circle):hover::after{
    transform: rotate(-45deg);
}

.cell.circle::before,
.cell.circle::after,
.board.circle .cell:not(.x):not(.circle):hover::before,
.board.circle .cell:not(.x):not(.circle):hover::after{
    content: '';
    position: absolute;
    border-radius: 50%;
}
.cell.circle::before,
.board.circle .cell:not(.x):not(.circle):hover::before{
    width: var(--mark-size);
    height: var(--mark-size);
}
.cell.circle::after,
.board.circle .cell:not(.x):not(.circle):hover::after{
    width: calc(var(--mark-size) *.7);
    height: calc(var(--mark-size) *.7);
    background-color: white;
}

.win-screen{
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, .9);
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 5rem;
    flex-direction: column;
}

.win-screen button{
    font-size: 3rem;
    background-color: white;
    padding: 10px;
    border-radius: 50px;
    cursor: pointer;
    width: 400px;
    transition: all 0.5s ease;
}

.win-screen button:hover{
    background-color: #90EE90;
    color: white;
    width: 250px;
}

.win-screen.show{
    display: flex;
}