:root {
    --bg-color: #f0f2f5;
    --text-color: #333;
    --container-bg: #fff;
    --primary-color: #008CBA;
    --primary-hover: #005f7a;
    --secondary-color: #4CAF50;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --btn-text-color: #fff;
    --theme-btn-bg: #fff;
    --theme-btn-color: #333;
    --input-bg: #fff;
    --input-border: #ccc;
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --text-color: #f0f2f5;
    --container-bg: #2d2d2d;
    --primary-color: #4db8ff;
    --primary-hover: #008CBA;
    --secondary-color: #66bb6a;
    --shadow-color: rgba(0, 0, 0, 0.5);
    --btn-text-color: #1a1a1a;
    --theme-btn-bg: #2d2d2d;
    --theme-btn-color: #f0f2f5;
    --input-bg: #3d3d3d;
    --input-border: #555;
}

body {
    font-family: 'Arial', 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 ease, color 0.3s ease;
    padding: 20px 0;
}

.container {
    background-color: var(--container-bg);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 20px var(--shadow-color);
    text-align: center;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    width: 90%;
    max-width: 500px;
}

h1 {
    color: var(--text-color);
    margin-bottom: 20px;
    transition: color 0.3s ease;
}

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

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

.generate-btn {
    background-color: var(--primary-color);
    color: var(--btn-text-color);
    padding: 15px 30px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 18px;
    font-weight: bold;
    transition: background-color 0.3s ease, color 0.3s ease;
    width: 100%;
}

.generate-btn:hover {
    background-color: var(--primary-hover);
}

/* Theme Toggle Button */
.theme-toggle-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--theme-btn-bg);
    color: var(--theme-btn-color);
    border: 2px solid var(--theme-btn-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 8px var(--shadow-color);
    z-index: 1000;
}

.theme-toggle-btn:hover {
    transform: scale(1.1);
}

.icon-moon {
    display: none;
}

body.dark-mode .icon-sun {
    display: none;
}

body.dark-mode .icon-moon {
    display: inline;
}

/* Form Styles */
.form-container {
    margin-top: 40px;
    text-align: left;
}

.form-container hr {
    border: 0;
    border-top: 1px solid var(--input-border);
    margin-bottom: 30px;
}

.form-container h3 {
    text-align: center;
    margin-bottom: 20px;
}

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

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

.form-group input, 
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--input-border);
    border-radius: 5px;
    background-color: var(--input-bg);
    color: var(--text-color);
    box-sizing: border-box;
    font-family: inherit;
}

.form-group textarea {
    height: 100px;
    resize: none;
}

.submit-btn {
    background-color: var(--secondary-color);
    color: white;
    padding: 12px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    width: 100%;
    transition: opacity 0.3s ease;
}

.submit-btn:hover {
    opacity: 0.9;
}