:root {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --text-color: #333333;
    --btn-primary: #008CBA;
    --btn-primary-hover: #007B9A;
    --btn-primary-active: #005F6B;
    --number-bg: #4CAF50;
    --number-color: #ffffff;
    --shadow: rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] {
    --bg-color: #121212;
    --container-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --btn-primary: #00bcd4;
    --btn-primary-hover: #00acc1;
    --btn-primary-active: #0097a7;
    --number-bg: #81c784;
    --number-color: #121212;
    --shadow: rgba(255, 255, 255, 0.05);
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Helvetica Neue', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    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 30px var(--shadow);
    transition: background-color 0.3s, box-shadow 0.3s;
    position: relative;
}

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

.numbers {
    display: flex;
    justify-content: center;
    margin-bottom: 30px;
}

.number {
    width: 60px;
    height: 60px;
    background-color: var(--number-bg);
    color: var(--number-color);
    font-size: 24px;
    font-weight: bold;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    transition: background-color 0.3s, color 0.3s;
}

#generate {
    background-color: var(--btn-primary);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s;
}

#generate:hover {
    background-color: var(--btn-primary-hover);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

#generate:active {
    background-color: var(--btn-primary-active);
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: 2px solid var(--text-color);
    color: var(--text-color);
    padding: 5px 10px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s;
}

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