:root {
    --bg-color: #f0f2f5;
    --container-bg-color: white;
    --text-color: #333;
    --button-bg-color: #007bff;
    --button-text-color: white;
    --button-hover-bg-color: #0056b3;
    --number-bg-color: #f8f9fa;
    --number-border-color: #dee2e6;
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --container-bg-color: #2c2c2c;
    --text-color: #f0f0f0;
    --button-bg-color: #0056b3;
    --button-text-color: #ffffff;
    --button-hover-bg-color: #007bff;
    --number-bg-color: #3d3d3d;
    --number-border-color: #555555;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: var(--bg-color);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    text-align: center;
    background-color: var(--container-bg-color);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

h1 {
    color: var(--text-color);
    margin-bottom: 24px;
}

#generate {
    background-color: var(--button-bg-color);
    color: var(--button-text-color);
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-bottom: 24px;
}

#generate:hover {
    background-color: var(--button-hover-bg-color);
}

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.number {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--number-bg-color);
    border: 1px solid var(--number-border-color);
    font-size: 20px;
    font-weight: bold;
    color: var(--text-color);
}

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

.theme-switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: #2196F3;
}

input:checked + .slider:before {
    transform: translateX(26px);
}