body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #667eea, #764ba2);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}
.container {
    background: #fff;
    width: 90%;
    max-width: 500px;
    padding: 30px;
    border-radius: 18px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}
h1 {
    text-align: center;
    margin-bottom: 10px;
}
p {
    text-align: center;
    color: #555;
}
button {
    width: 100%;
    margin-top: 20px;
    padding: 15px;
    font-size: 17px;
    background: #2ecc71;
    color: white;
    border: none;
    border-radius: 12px;
    cursor: pointer;
}
button:active {
    transform: scale(0.97);
}

.set {
    margin-top: 25px;
    padding-top: 15px;
    border-top: 1px solid #ddd;
}
.set-title {
    font-weight: bold;
    margin-bottom: 10px;
}

/* 🎯 로또 공 */
.ball {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    margin: 4px;
    border-radius: 50%;
    font-weight: bold;
    color: white;
    font-size: 16px;
    animation: pop 0.35s ease;
}
.bonus {
    border: 3px solid #000;
}

@keyframes pop {
    0% { transform: scale(0); }
    70% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

/* 색상 구간 */
.n1 { background: #f1c40f; } /* 1~10 */
.n2 { background: #3498db; } /* 11~20 */
.n3 { background: #e74c3c; } /* 21~30 */
.n4 { background: #7f8c8d; } /* 31~40 */
.n5 { background: #2ecc71; } /* 41~45 */