:root {
    --main-bg-color: #f0f0f0;
    --container-bg-color: #ffffff;
    --primary-color: #4a90e2;
    --secondary-color: #ff7f50;
    --text-color: #333333;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --gradient-start: #4a90e2;
    --gradient-end: #ff7f50;
}

body.dark-theme {
    --main-bg-color: #1a1a1a;
    --container-bg-color: #2d2d2d;
    --primary-color: #64b5f6;
    --secondary-color: #ffab91;
    --text-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.4);
    --gradient-start: #1e3a5f;
    --gradient-end: #5f3e1e;
}

body {
    background-color: var(--main-bg-color);
    font-family: 'Helvetica Neue', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-image: 
        linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px),
        linear-gradient(45deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    background-size: 20px 20px, 20px 20px, 100% 100%;
    transition: background-color 0.3s ease, background-image 0.3s ease;
}

.container {
    background-color: var(--container-bg-color);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow-color);
    text-align: center;
    width: 90%;
    max-width: 600px;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    margin: 20px;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
}

#theme-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 5px;
    border-radius: 50%;
    transition: transform 0.3s ease;
}

#theme-btn:hover {
    transform: rotate(20deg);
}

h1 {
    color: var(--text-color);
    font-size: 2.5rem;
    margin-bottom: 30px;
}

#generate-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.2rem;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(74, 144, 226, 0.4);
}

#generate-btn:hover {
    background-color: #357abd;
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(74, 144, 226, 0.5);
}

lotto-display {
    display: block;
    margin-bottom: 30px;
}