:root {
    --bg-color: #f0f2f5;
    --text-color: #333;
    --primary-color: #4a90e2;
    --white: #ffffff;
    --border-radius: 12px;
    --shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background: var(--white);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    width: 90%;
    max-width: 500px;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.lotto-numbers {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
}

.lotto-ball {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--white);
    box-shadow: inset -5px -5px 10px rgba(0, 0, 0, 0.2);
}

#generate-btn {
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 1rem 2rem;
    font-size: 1.2rem;
    font-weight: bold;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.4);
}

#generate-btn:hover {
    background-color: #357ABD;
    transform: translateY(-2px);
}