#bg-x-canvas {
    position: fixed;
    left: 0;
    top: 0;
    width: 100vw;
    height: 100vh;
    z-index: 0;
    pointer-events: none;
    display: block;
}

body {
    background-color: #001524;
    min-height: 100svh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    font-family: Arial, sans-serif;
    overflow: hidden;
    padding: clamp(8px, 2vmin, 20px);
    gap: clamp(6px, 1.5vmin, 12px);
    position: relative;
    isolation: isolate;
}

body::before,
body::after {
    content: '';
    position: fixed;
    left: 50%;
    top: 50%;
    width: 90vmax;
    height: 90vmax;
    margin-left: -45vmax;
    margin-top: -45vmax;
    z-index: 0;
    pointer-events: none;
    opacity: 0.4;
}

:root {
    --cell-size: clamp(72px, 18vmin, 170px);
    --grid-gap: clamp(10px, 3vmin, 36px);
    --grid-padding: clamp(10px, 3vmin, 40px);
    --grid-border: clamp(3px, 0.6vmin, 7px);
    --grid-border-win: clamp(6px, 1.2vmin, 14px);
    --cell-radius: clamp(10px, 2vmin, 25px);
}

#titleBlock {
    width: min(90vw, 520px);
    min-height: clamp(60px, 10vmin, 120px);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: clamp(8px, 2vmin, 18px);
    position: relative;
    z-index: 1;
}

h1 {
    color: #C8963E;
    font-size: clamp(28px, 5vmin, 52px);
    margin: 0;
}

#winner {
    color: #C8963E;
    font-size: clamp(18px, 4vmin, 40px);
    min-height: 1.2em;
}



#grid {
    --grid-frame-color: #15616D;
    background-color: #001524;
    display: grid;
    grid-template-areas: "a a a"
        "a a a"
        "a a a";
    grid-gap: var(--grid-gap);
    padding: var(--grid-padding);
    border-style: solid;
    border-width: var(--grid-border);
    border-radius: var(--cell-radius);
    border-color: var(--grid-frame-color);
    color: var(--grid-frame-color);
    box-sizing: border-box;
    position: relative;
    z-index: 2;
    transition: border-color 0.4s, box-shadow 0.4s;
}

#grid::before {
    content: '';
    position: absolute;
    inset: calc(var(--grid-border-win) - var(--grid-border));
    border: var(--grid-border) solid var(--grid-frame-color);
    border-radius: calc(var(--cell-radius) - (var(--grid-border-win) - var(--grid-border)));
    pointer-events: none;
}

#grid.is-finished {
    box-shadow: 0 0 0 8px rgba(200, 150, 62, 0.25), 0 0 24px 4px var(--grid-frame-color);
    border-color: var(--grid-frame-color);
}

#grid.is-finished::before {
    opacity: 0;
}

#scoreboard {
    margin-top: clamp(8px, 2vmin, 20px);
    display: flex;
    gap: clamp(16px, 4vmin, 36px);
    font-size: clamp(16px, 3.2vmin, 38px);
    letter-spacing: 0.04em;
    position: relative;
    z-index: 1;
}

.score-item {
    font-weight: 700;
}

.score-x {
    color: #A63D40;
}

.score-o {
    color: #CFFFB3;
}

.buttonSquare {
    position: relative;
    width: var(--cell-size);
    height: var(--cell-size);
    border-radius: var(--cell-radius);
    border-color: #15616D;
    background-color: #001524;
    border-style: solid;
    border-width: var(--grid-border);
    color: #15616D;

    transition: transform .5s, font-size .5s;

    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 3;
    background: #001524;
    box-shadow: 0 0 0 8px #001524;
}

button:hover {
    transform: scale(1.1);
}

.O {
    position: absolute;
    z-index: 0;
}

.X {
    position: absolute;
    z-index: 0;
}

.O-outer {
    width: calc(var(--cell-size) * 0.72);
    height: calc(var(--cell-size) * 0.72);
    border-radius: 50%;
    background-color: #CFFFB3;
    display: flex;
    align-items: center;
    justify-content: center;
}

.O-inner {
    width: calc(var(--cell-size) * 0.56);
    height: calc(var(--cell-size) * 0.56);
    border-radius: 50%;
    background-color: #001524;
}


.X-left, .X-right {
    width: calc(var(--cell-size) * 0.10);
    height: calc(var(--cell-size) * 0.78);
    background-color: #A63D40;
    position: absolute;
    left: 50%;
    top: 50%;
    transform-origin: center center;
    border-radius: calc(var(--cell-size) * 0.04);
}

.X-left {
    transform: translate(-50%, -50%) rotate(45deg);
}
.X-right {
    transform: translate(-50%, -50%) rotate(90deg);
}