:root {
    /* Default - Dark Mode */
    --primary-color: #f39c12;
    --secondary-color: #f1c40f;
    --background-color: #2c3e50;
    --text-color: #ecf0f1;
    --container-bg-color: #34495e;
    --gradient-start: #34495e;
    --gradient-end: #2c3e50;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --btn-text-color: #2c3e50;
}

[data-theme="light"] {
    --primary-color: #e67e22;
    --secondary-color: #d35400;
    --background-color: #ecf0f1;
    --text-color: #2c3e50;
    --container-bg-color: #ffffff;
    --gradient-start: #ecf0f1;
    --gradient-end: #bdc3c7;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --btn-text-color: #ffffff;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-image: linear-gradient(45deg, var(--gradient-start), var(--gradient-end));
    transition: background-color 0.3s, color 0.3s, background-image 0.3s;
}

.container {
    background-color: var(--container-bg-color);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 10px 20px var(--shadow-color), 0 6px 6px var(--shadow-color);
    text-align: center;
    max-width: 500px;
    width: 90%;
    transition: background-color 0.3s, box-shadow 0.3s;
    position: relative;
}

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

#theme-btn {
    background: none;
    border: 1px solid var(--primary-color);
    color: var(--text-color);
    padding: 5px 10px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9em;
    transition: all 0.3s;
}

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

h1 {
    color: var(--primary-color);
    margin-bottom: 30px;
    font-size: 2.5em;
    transition: color 0.3s;
}

#generate {
    background-color: var(--primary-color);
    color: var(--btn-text-color);
    border: none;
    padding: 15px 30px;
    font-size: 1.2em;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    box-shadow: 0 4px 6px var(--shadow-color);
}

#generate:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
}

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

.number {
    background-color: var(--primary-color);
    color: var(--btn-text-color);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.8em;
    margin: 10px;
    font-weight: bold;
    box-shadow: 0 2px 4px var(--shadow-color);
    animation: pop-in 0.5s ease-out forwards;
    opacity: 0;
    transition: background-color 0.3s, color 0.3s;
}

.divider {
    border: 0;
    height: 1px;
    background-image: linear-gradient(to right, rgba(0, 0, 0, 0), var(--primary-color), rgba(0, 0, 0, 0));
    margin: 40px 0;
}

.contact-section h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.5em;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.contact-form input,
.contact-form textarea {
    padding: 12px;
    border-radius: 8px;
    border: 1px solid var(--primary-color);
    background-color: var(--background-color);
    color: var(--text-color);
    font-family: inherit;
    transition: all 0.3s;
}

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

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    box-shadow: 0 0 8px var(--primary-color);
}

#submit-btn {
    background-color: var(--primary-color);
    color: var(--btn-text-color);
    border: none;
    padding: 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1em;
    font-weight: bold;
    transition: all 0.3s;
}

#submit-btn:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
}

@keyframes pop-in {
    from {
        transform: scale(0.5);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}