:root {
    --background-color: #f0f2f5;
    --card-background-color: #ffffff;
    --primary-color: #4a90e2;
    --primary-hover-color: #357abd;
    --text-color: #333333;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --ball-size: 50px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    background-image: url('data:image/svg+xml,%3Csvg width="60" height="60" viewBox="0 0 60 60" xmlns="http://www.w3.org/2000/svg"%3E%3Cg fill="none" fill-rule="evenodd"%3E%3Cg fill="%239C92AC" fill-opacity="0.04"%3E%3Cpath d="M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z"/%3E%3C/g%3E%3C/g%3E%3C/svg%3E');
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    color: var(--text-color);
}

.app-container {
    background-color: var(--card-background-color);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 30px var(--shadow-color);
    text-align: center;
    max-width: 90%;
    width: 400px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.app-container:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.app-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.app-description {
    font-size: 1.1rem;
    margin-bottom: 30px;
    color: #666;
}

.lotto-display {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 30px;
    min-height: 70px;
}

.generate-btn {
    background-color: var(--primary-color);
    color: white;
    font-size: 1.2rem;
    font-weight: 600;
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.4);
}

.generate-btn:hover {
    background-color: var(--primary-hover-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.5);
}

.generate-btn:active {
    transform: translateY(0);
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.4);
}

/* Responsive Design */
@media (max-width: 480px) {
    .app-container {
        padding: 30px;
    }

    .app-title {
        font-size: 2rem;
    }

    .app-description {
        font-size: 1rem;
    }

    :root {
        --ball-size: 40px;
    }

    .generate-btn {
        padding: 12px 25px;
        font-size: 1.1rem;
    }
}