:root {
    --bg-color: #f0f0f0;
    --container-bg: #fff;
    --text-color: #333;
    --heading-color: #333;
    --history-item-bg: #eee;
    --shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    --btn-bg: #4CAF50;
    --btn-hover: #45a049;
    --number-bg: #3498db;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --container-bg: #2d2d2d;
    --text-color: #f0f0f0;
    --heading-color: #fff;
    --history-item-bg: #3d3d3d;
    --shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    --btn-bg: #2ecc71;
    --btn-hover: #27ae60;
    --number-bg: #2980b9;
}

body {
    font-family: sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color 0.3s, color 0.3s;
}

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

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

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

#theme-btn {
    background: none;
    border: 2px solid var(--text-color);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s;
}

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

.generator-container {
    margin-bottom: 2rem;
}

#generate-btn {
    background-color: var(--btn-bg);
    color: white;
    padding: 1rem 2rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

#generate-btn:hover {
    background-color: var(--btn-hover);
    box-shadow: 0 6px 12px rgba(0,0,0,0.3);
}

.numbers-display {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
}

.number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: #fff;
    background-color: var(--number-bg);
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    transition: background-color 0.3s;
}

.history-container {
    margin-top: 2rem;
}

#view-history-btn {
    background-color: var(--container-bg);
    color: var(--text-color);
    padding: 0.5rem 1.5rem;
    border: 2px solid var(--text-color);
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s;
}

#view-history-btn:hover {
    background-color: var(--text-color);
    color: var(--container-bg);
}