:root {
    --bg-color: #f0f2f5;
    --container-bg: white;
    --text-color: #333;
    --number-bg: #4CAF50;
    --button-bg: #007BFF;
    --button-hover: #0056b3;
}

.dark-mode {
    --bg-color: #18191a;
    --container-bg: #242526;
    --text-color: #e4e6eb;
    --number-bg: #2e7d32;
    --button-bg: #3a3b3c;
    --button-hover: #4e4f50;
}

body {
    font-family: 'Helvetica Neue', sans-serif;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    margin: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    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 25px rgba(0, 0, 0, 0.1);
    transition: background-color 0.3s;
    position: relative;
    width: 100%;
    max-width: 500px;
    box-sizing: border-box;
}

.contact-section {
    margin-top: 40px;
}

.contact-section h2 {
    margin-bottom: 20px;
}

.form-group {
    text-align: left;
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

.form-group input, 
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 8px;
    background-color: var(--container-bg);
    color: var(--text-color);
    box-sizing: border-box;
    font-size: 16px;
    transition: border-color 0.3s;
}

.dark-mode .form-group input, 
.dark-mode .form-group textarea {
    border-color: #444;
}

.form-group input:focus, 
.form-group textarea:focus {
    outline: none;
    border-color: var(--button-bg);
}

.submit-btn {
    width: 100%;
    padding: 15px;
    border: none;
    border-radius: 10px;
    background-color: var(--button-bg);
    color: white;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.submit-btn:hover {
    background-color: var(--button-hover);
}

.theme-toggle {
    position: absolute;
    top: 15px;
    right: 15px;
}

#theme-btn {
    background: none;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 5px 10px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
}

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

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

.number {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    margin: 0 5px;
    border-radius: 50%;
    background-color: var(--number-bg);
    color: white;
    font-size: 24px;
    font-weight: bold;
}

#generate-btn {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    background-color: var(--button-bg);
    color: white;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

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