:root {
    --bg-main: linear-gradient(135deg, #020617, #0f172a, #020617);
    --text-color: #ffffff;

    --card-bg: rgba(255, 255, 255, 0.05);
    --card-hover: rgba(255, 255, 255, 0.08);
    --border-light: rgba(255, 255, 255, 0.08);

    --board-bg: rgba(2, 6, 23, 0.9);

    --primary: #22c55e;
    --primary-light: #4ade80;
    --primary-dark: #16a34a;

    --danger: #ff4d4d;
    --danger-dark: #b91c1c;

    --shadow-glow: 0 0 25px rgba(34, 197, 94, 0.15);
    --radius: 14px;
}

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

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

.app {
    width: 100%;
    max-width: 900px;
    padding: 15px;
}

.top-bar {
    display: flex;
    gap: 12px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.card {
    flex: 1;
    text-align: center;
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    padding: 14px;
    border-radius: var(--radius);
    font-weight: 600;
    border: 1px solid var(--border-light);
    transition: 0.3s;
}

.card:hover {
    transform: translateY(-3px);
    background: var(--card-hover);
}

.game-area {
    display: flex;
    justify-content: center;
}

.board {
    width: 100%;
    max-width: 520px;
    aspect-ratio: 1;
    display: grid;
    grid-template-columns: repeat(20, 1fr);
    background: var(--board-bg);
    border-radius: 20px;
    overflow: hidden;
    border: 2px solid rgba(34, 197, 94, 0.2);
    box-shadow: var(--shadow-glow);
}

.block {
    border: 1px solid rgba(255, 255, 255, 0.02);
}

.fill {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 6px;
    box-shadow: 0 0 8px var(--primary);
}

.food {
    background: radial-gradient(circle, var(--danger), var(--danger-dark));
    border-radius: 50%;
    box-shadow: 0 0 10px var(--danger);
}

.modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    display: flex;
    justify-content: center;
    align-items: center;
}

.modal-box {
    background: rgba(30, 41, 59, 0.8);
    backdrop-filter: blur(15px);
    padding: 35px;
    border-radius: 20px;
    text-align: center;
    width: 90%;
    max-width: 320px;
    border: 1px solid var(--border-light);
    animation: pop 0.3s ease;
}

@keyframes pop {
    from {
        transform: scale(0.8);
        opacity: 0;
    }

    to {
        transform: scale(1);
        opacity: 1;
    }
}

.game-over {
    display: none;
}

.btn {
    margin-top: 18px;
    padding: 12px;
    width: 100%;
    border: none;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    font-weight: bold;
    border-radius: 12px;
    cursor: pointer;
    color: white;
    transition: 0.3s;
    box-shadow: 0 5px 15px rgba(34, 197, 94, 0.3);
}

.btn:hover {
    transform: translateY(-2px);
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
}

@media (max-width: 500px) {
    .card {
        font-size: 12px;
        padding: 10px;
    }

    .board {
        max-width: 95vw;
    }

    .modal-box {
        padding: 25px;
    }
}