@import url("https://fonts.googleapis.com/css2?family=Russo+One&family=Nunito:wght@500;700;800&display=swap");

:root {
    --bg-a: #07172a;
    --bg-b: #0d2a44;
    --panel: rgba(10, 33, 58, 0.85);
    --text: #e9f2ff;
    --muted: #b4c7df;
    --line: rgba(224, 241, 255, 0.22);
    --board: #123f69;
    --slot: #071a2f;
    --human: #ffb347;
    --ai: #ff556a;
    --button: #1d6fb5;
    --button-hover: #2a84d2;
    --cell-size: clamp(24px, 5.2vw, 36px);
}

body {
    min-height: 90vh;
    margin: 0;
    background:
        radial-gradient(circle at 12% 18%, rgba(43, 145, 220, 0.35) 0%, transparent 38%),
        radial-gradient(circle at 86% 20%, rgba(255, 179, 71, 0.2) 0%, transparent 32%),
        linear-gradient(145deg, var(--bg-a), var(--bg-b));
    color: var(--text);
    font-family: "Nunito", sans-serif;
    padding: 20px 14px;
}

.container {
    min-height: calc(100vh - 40px);
}

.c4-shell {
    width: min(94vw, 430px);
    background: var(--panel);
    border: 2px solid var(--line);
    border-radius: 22px;
    box-shadow: 0 18px 40px rgba(4, 11, 20, 0.45);
    padding: 20px 14px 16px;
}

h1 {
    margin: 0;
    font-family: "Russo One", sans-serif;
    font-size: clamp(1.8rem, 6vw, 2.4rem);
    letter-spacing: 0.8px;
}

.subtitle {
    margin: 4px 0 12px;
    color: var(--muted);
    font-weight: 700;
}

.score-strip {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    margin-bottom: 10px;
}

.score-pill {
    border-radius: 999px;
    padding: 7px 9px;
    font-size: 0.88rem;
    font-weight: 800;
    border: 1px solid var(--line);
    background: rgba(10, 31, 53, 0.78);
}

.status {
    min-height: 24px;
    margin: 8px 0 10px;
    font-weight: 800;
    font-size: 0.92rem;
}

.board {
    display: grid;
    grid-template-columns: repeat(7, var(--cell-size));
    grid-template-rows: repeat(6, var(--cell-size));
    justify-content: center;
    gap: 4px;
    background: var(--board);
    border-radius: 12px;
    padding: 8px;
    border: 1px solid rgba(233, 242, 255, 0.18);
    margin-inline: auto;
}

.cell {
    width: var(--cell-size);
    height: var(--cell-size);
    border-radius: 50%;
    border: 2px solid rgba(0, 0, 0, 0.3);
    background: var(--slot);
    box-shadow: inset 0 4px 8px rgba(0, 0, 0, 0.3);
    transition: transform 0.14s ease, outline-color 0.14s ease;
    cursor: pointer;
}

.board.playable .cell.column-hover {
    transform: scale(1.06);
    outline: 2px solid rgba(233, 242, 255, 0.38);
    outline-offset: -1px;
}

.cell.human {
    background: radial-gradient(circle at 28% 22%, #ffd8a3, var(--human) 58%, #d8821e 100%);
}

.cell.ai {
    background: radial-gradient(circle at 28% 22%, #ffb1bc, var(--ai) 56%, #b6112e 100%);
}

.actions {
    margin-top: 12px;
    display: flex;
    justify-content: center;
}

.btn {
    border: 1px solid rgba(233, 242, 255, 0.25);
    border-radius: 12px;
    padding: 8px 14px;
    font-size: 0.9rem;
    font-weight: 800;
    color: var(--text);
    background: var(--button);
    cursor: pointer;
}

.btn:hover {
    background: var(--button-hover);
}

@media (max-width: 560px) {
    .c4-shell {
        padding: 16px 10px 14px;
    }

    .score-strip {
        grid-template-columns: 1fr;
    }

    .board {
        gap: 3px;
        padding: 7px;
    }
}