:root {
    --primary-color: #3498db;
    --background-color: #f2f2f2;
    --text-color: #333;
    --container-bg: #fff;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --btn-hover: #2980b9;
}

body.dark-mode {
    --background-color: #1a1a1a;
    --text-color: #f2f2f2;
    --container-bg: #2c3e50;
    --shadow-color: rgba(0, 0, 0, 0.5);
    --btn-hover: #5dade2;
}

body {
    font-family: 'Helvetica Neue', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--text-color);
    background-image: url("data:image/svg+xml,%3Csvg width='6' height='6' viewBox='0 0 6 6' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%239C92AC' fill-opacity='0.1'%3E%3Cpath d='M5 0h1L0 6V5zM6 5v1H5z'/%3E%3C/g%3E%3C/svg%3E");
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    text-align: center;
    background-color: var(--container-bg);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 10px 20px var(--shadow-color);
    max-width: 400px;
    width: 90%;
    position: relative;
    transition: background-color 0.3s, box-shadow 0.3s;
}

#theme-toggle {
    position: absolute;
    top: 15px;
    right: 15px;
    background: none;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 5px 10px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: all 0.3s;
}

#theme-toggle:hover {
    background-color: var(--text-color);
    color: var(--container-bg);
}

h1 {
    color: var(--text-color);
    margin-bottom: 30px;
}

#lotto-numbers {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 30px;
}

.lotto-ball {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--white);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

#generate-btn {
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 15px 30px;
    font-size: 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s;
    box-shadow: 0 0 10px rgba(52, 152, 219, 0.5);
}

#generate-btn:hover {
    background-color: #2980b9;
    box-shadow: 0 0 20px rgba(52, 152, 219, 0.8);
}

@media (max-width: 480px) {
    .container {
        padding: 20px;
    }

    .lotto-ball {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }

    #generate-btn {
        padding: 12px 25px;
        font-size: 1rem;
    }
}