:root {
    /* Light Mode Variables */
    --primary-color: #4CAF50; /* A fresh green */
    --secondary-color: #FFC107; /* A warm yellow */
    --background-color: #e0f2f1; /* Light teal background */
    --text-color: #263238; /* Dark slate */
    --white: #FFFFFF;
    --shadow-color-1: rgba(0, 0, 0, 0.15);
    --shadow-color-2: rgba(0, 0, 0, 0.25);
    --border-color: #B2DFDB; /* Light teal border */
    --background-color-light: #f5f5f5; /* Lighter grey for elements */
    --button-text-color: var(--white);
    --primary-color-rgb: 76, 175, 80; /* RGB for primary-color */
}

body.dark-mode {
    /* Dark Mode Variables */
    --primary-color: #66BB6A; /* Lighter green for dark mode contrast */
    --secondary-color: #FFD54F; /* Lighter yellow for dark mode contrast */
    --background-color: #212121; /* Dark grey background */
    --text-color: #E0E0E0; /* Light grey text */
    --white: #424242; /* Darker 'white' for elements that were white */
    --shadow-color-1: rgba(0, 0, 0, 0.3);
    --shadow-color-2: rgba(0, 0, 0, 0.5);
    --border-color: #4CAF50; /* Greenish border */
    --background-color-light: #303030; /* Darker grey for elements */
    --button-text-color: var(--text-color);
    --primary-color-rgb: 102, 187, 106; /* RGB for primary-color in dark mode */
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    box-sizing: border-box;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    background: var(--white);
    border-radius: 15px;
    padding: 2.5rem;
    box-shadow: 0 10px 20px var(--shadow-color-1), 0 6px 6px var(--shadow-color-2);
    text-align: center;
    max-width: 600px;
    width: 100%;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

h1 {
    font-size: 2.8rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-shadow: 1px 1px 2px var(--shadow-color-1);
    transition: color 0.3s ease, text-shadow 0.3s ease;
}

.controls {
    margin-bottom: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.controls label {
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--text-color);
    transition: color 0.3s ease;
}

.controls input[type="number"] {
    padding: 10px 15px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    width: 80px;
    text-align: center;
    -moz-appearance: textfield; /* Firefox */
    background-color: var(--background-color-light);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

.controls input[type="number"]::-webkit-outer-spin-button,
.controls input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

#generateBtn {
    background-color: var(--primary-color);
    color: var(--button-text-color);
    border: none;
    padding: 12px 25px;
    font-size: 1.1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px var(--shadow-color-1);
    font-weight: bold;
}

#generateBtn:hover {
    background-color: #43A047; /* Slightly darker green */
    transform: translateY(-2px);
    box-shadow: 0 6px 8px var(--shadow-color-2);
}

/* Theme Toggle Switch */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 1rem;
    gap: 10px;
}

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

.theme-switch input {
    display: none;
}

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

.slider:before {
    background-color: #fff;
    bottom: 4px;
    content: "";
    height: 26px;
    left: 4px;
    position: absolute;
    transition: .4s;
    width: 26px;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

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

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

.theme-switch-wrapper span {
    font-size: 0.9rem;
    color: var(--text-color);
    transition: color 0.3s ease;
}

/* Styles for lotto-generator (shadow DOM) are handled internally by main.js */
lotto-generator {
    display: block; /* Ensure it takes up space */
}

/* Contact Form Section */
.contact-form-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.contact-form-section h2 {
    font-size: 2.2rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    text-shadow: 1px 1px 2px var(--shadow-color-1);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
    text-align: left;
    max-width: 400px;
    margin: 0 auto;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 1rem;
    font-weight: bold;
    margin-bottom: 5px;
    color: var(--text-color);
}

.contact-form input[type="text"],
.contact-form input[type="email"],
.contact-form textarea {
    padding: 10px;
    font-size: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--background-color-light);
    color: var(--text-color);
    transition: all 0.3s ease;
}

.contact-form input[type="text"]:focus,
.contact-form input[type="email"] 또는:focus,
.contact-form textarea:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(var(--primary-color-rgb), 0.3);
    outline: none;
}

.contact-form textarea {
    resize: vertical;
    min-height: 100px;
}

.submit-btn {
    background-color: var(--secondary-color);
    color: var(--text-color);
    border: none;
    padding: 12px 25px;
    font-size: 1.1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px var(--shadow-color-1);
    font-weight: bold;
    margin-top: 1rem;
}

.submit-btn:hover {
    background-color: #FFB300; /* Slightly darker yellow */
    transform: translateY(-2px);
    box-shadow: 0 6px 8px var(--shadow-color-2);
}

.formspree-notice {
    font-size: 0.85rem;
    color: var(--text-color);
    margin-top: 1rem;
}

.formspree-notice a {
    color: var(--primary-color);
    text-decoration: none;
}

.formspree-notice a:hover {
    text-decoration: underline;
}