body {
    margin: 0;
    padding: 0;
    height: 100vh;
    font-family: Arial, sans-serif;

    /* Nền sân cỏ */
    background: linear-gradient(
        180deg,
        #2e7d32 0%,
        #388e3c 50%,
        #1b5e20 100%
    );

    /* Tạo vân sân bóng */
    background-size: 100% 40px;
}

/* Thêm lớp overlay tạo vạch sân */
body::before {
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(white 2px, transparent 2px),
        linear-gradient(90deg, white 2px, transparent 2px);
    background-size: 200px 200px;
    opacity: 0.15;
    pointer-events: none;
}

.ball {
    position: absolute;
    width: 120px;
    height: 120px;
    bottom: 30px;
    right: 30px;

    background: url('https://upload.wikimedia.org/wikipedia/commons/d/d3/Soccerball.svg') no-repeat center/cover;
    
    border-radius: 50%;
    box-shadow: 0 10px 25px rgba(0,0,0,0.6);

    animation: bounce 1.8s infinite ease-in-out,
               spin 6s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Hiệu ứng nảy */
@keyframes bounce {
    0%, 100% {
        transform: translateY(0) scale(1);
    }
    40% {
        transform: translateY(-35px) scale(1.05);
    }
    60% {
        transform: translateY(-20px) scale(0.95);
    }
}

/* Tiêu đề */
.title {
    margin-top: 30px;
    font-size: 48px;
    text-shadow: 0 0 15px #00ff88;
}

/* Bảng xếp hạng */
.leaderboard {
    margin-top: 40px;
}

/* Mỗi người */
.player {
    font-size: 24px;
    margin: 10px auto;
    padding: 10px;
    width: 300px;
    border-radius: 10px;
    background: rgba(0,0,0,0.3);
    transition: 0.3s;
}

/* Hover */
.player:hover {
    transform: scale(1.05);
    background: rgba(0,0,0,0.6);
}

/* Top 1-2-3 nổi bật */
.top1 {
    color: gold;
    font-weight: bold;
}

.top2 {
    color: silver;
}

.top3 {
    color: #cd7f32; /* đồng */
}

/* Nút quay lại */
.back {
    display: inline-block;
    margin-top: 40px;
    color: #00ff88;
    text-decoration: none;
    font-size: 20px;
}

.back:hover {
    text-shadow: 0 0 10px #00ff88;
}