:root,
[data-theme="light"] {
    --primary-color: #4a90e2;
    --secondary-color: #f5a623;
    --background-color: #f0f2f5;
    --text-color: #333;
    --white: #fff;
    --container-bg: #fff;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] {
    --primary-color: #64a8f0;
    --secondary-color: #f5a623;
    --background-color: #1a1a2e;
    --text-color: #e0e0e0;
    --white: #16213e;
    --container-bg: #16213e;
    --shadow-color: rgba(0, 0, 0, 0.4);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    text-align: center;
    background: var(--container-bg);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px var(--shadow-color);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

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

#generate-btn {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 1rem 2rem;
    font-size: 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 4px 15px var(--shadow-color);
}

#generate-btn:hover {
    background-color: #357abd;
    box-shadow: 0 6px 20px var(--shadow-color);
}

#theme-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 0.5rem 1.2rem;
    font-size: 0.9rem;
    border-radius: 20px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    z-index: 100;
}

#theme-toggle:hover {
    background-color: #357abd;
}