*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --bg:        #0d0d1a;
    --card:      #16213e;
    --border:    #1f3460;
    --cell-bg:   #0f3460;
    --cell-hover:#1a4a7a;
    --x-color:   #e94560;
    --o-color:   #4ecdc4;
    --text:      #eaeaea;
    --muted:     #8892a4;
    --radius:    12px;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Poppins', sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 40px 48px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.5);
}

.title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 2px;
    background: linear-gradient(135deg, var(--x-color), var(--o-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.scoreboard {
    display: flex;
    gap: 32px;
}

.player-label {
    font-size: 0.85rem;
    font-weight: 600;
    padding: 4px 16px;
    border-radius: 20px;
    letter-spacing: 1px;
}

.x-label {
    background: rgba(233, 69, 96, 0.15);
    color: var(--x-color);
    border: 1px solid rgba(233, 69, 96, 0.4);
}

.o-label {
    background: rgba(78, 205, 196, 0.15);
    color: var(--o-color);
    border: 1px solid rgba(78, 205, 196, 0.4);
}

.status {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--muted);
    min-height: 1.6rem;
    transition: color 0.3s;
}

.status.win   { color: var(--x-color); }
.status.lose  { color: var(--o-color); }
.status.draw  { color: #f7c948; }

.current-score {
    font-size: 1rem;
    font-weight: 600;
    color: var(--o-color);
    margin-top: -8px;
}

.board {
    display: grid;
    grid-template-columns: repeat(3, var(--cell-size, 90px));
    grid-template-rows: repeat(3, var(--cell-size, 90px));
    gap: 10px;
}

.cell {
    background: var(--cell-bg);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: background 0.15s, transform 0.1s;
    user-select: none;
}

.cell:hover:not(.taken) {
    background: var(--cell-hover);
    transform: scale(1.04);
}

.cell.taken {
    cursor: default;
}

.cell.x {
    color: var(--x-color);
    text-shadow: 0 0 16px rgba(233, 69, 96, 0.5);
}

.cell.o {
    color: var(--o-color);
    text-shadow: 0 0 16px rgba(78, 205, 196, 0.5);
}

@keyframes pop {
    0%   { transform: scale(0.5); opacity: 0; }
    70%  { transform: scale(1.15); }
    100% { transform: scale(1);   opacity: 1; }
}

.cell.pop {
    animation: pop 0.2s ease-out forwards;
}

.btn {
    background: linear-gradient(135deg, var(--x-color), #c2185b);
    color: #fff;
    border: none;
    border-radius: 10px;
    padding: 12px 36px;
    font-size: 0.95rem;
    font-weight: 600;
    font-family: 'Poppins', sans-serif;
    letter-spacing: 1px;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.1s;
}

.btn:hover  { opacity: 0.88; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-secondary {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--muted);
}
.btn-secondary:hover { background: rgba(255,255,255,0.05); opacity: 1; }

.game-buttons {
    display: flex;
    gap: 12px;
}

/* ---- setup screen ---- */

.mode-toggle {
    display: flex;
    background: rgba(0,0,0,0.3);
    border-radius: 10px;
    padding: 4px;
    gap: 4px;
}

.mode-btn {
    background: transparent;
    border: none;
    border-radius: 8px;
    color: var(--muted);
    font-family: 'Poppins', sans-serif;
    font-size: 0.9rem;
    font-weight: 600;
    padding: 8px 20px;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
}

.mode-btn.active {
    background: var(--cell-bg);
    color: var(--text);
}

.inputs {
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: 100%;
}

.name-input {
    background: var(--cell-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text);
    font-family: 'Poppins', sans-serif;
    font-size: 0.95rem;
    padding: 10px 16px;
    outline: none;
    transition: border-color 0.2s;
    width: 100%;
}

.name-input:focus {
    border-color: var(--x-color);
}

.name-input::placeholder {
    color: var(--muted);
}

.setup-error {
    color: var(--x-color);
    font-size: 0.85rem;
    margin-top: -8px;
}

.hidden {
    display: none !important;
}

/* ---- overlay / popup ---- */

.overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    backdrop-filter: blur(2px);
}

.popup {
    min-width: 320px;
    max-width: 480px;
    width: 90%;
    animation: fadeIn 0.15s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.95); }
    to   { opacity: 1; transform: scale(1); }
}

/* ---- leaderboard ---- */

.leaderboard-empty {
    color: var(--muted);
    font-size: 0.9rem;
    text-align: center;
}

.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.leaderboard-table th {
    color: var(--muted);
    font-weight: 600;
    text-align: left;
    padding: 4px 10px;
    border-bottom: 1px solid var(--border);
}

.leaderboard-table td {
    padding: 6px 10px;
    border-bottom: 1px solid rgba(31, 52, 96, 0.5);
    color: var(--text);
}

.leaderboard-table tbody tr:first-child td {
    color: #f7c948;
}

.leaderboard-table .points {
    font-weight: 700;
    color: var(--o-color);
}

.leaderboard-table tbody tr:first-child .points {
    color: #f7c948;
}

/* ---- responsive / mobile ---- */

@media (max-width: 480px) {
    body {
        align-items: flex-start;
        padding: 16px 0;
    }

    .container {
        padding: 28px 20px;
        gap: 18px;
        border-radius: 16px;
        width: 95vw;
    }

    .title {
        font-size: 1.5rem;
    }

    :root {
        --cell-size: calc((95vw - 40px - 20px) / 3);
    }

    .cell {
        font-size: 2rem;
    }

    .btn {
        padding: 12px 20px;
        font-size: 0.9rem;
        width: 100%;
    }

    .game-buttons {
        width: 100%;
        flex-direction: column;
    }

    .scoreboard {
        gap: 12px;
    }

    .popup {
        width: 95vw;
        max-height: 90vh;
        overflow-y: auto;
    }
}