:root {
    /* Light Mode */
    --background-color: #f8f9fa;
    --container-bg: #ffffff;
    --primary-color: #2e7d32;
    --primary-hover-color: #1b5e20;
    --text-color: #333;
    --secondary-text: #555;
    --border-color: #eee;
    --shadow-color: rgba(0, 0, 0, 0.05);
    --number-bg: #e8f5e9;
    --input-bg: #ffffff;
    --nav-bg: #ffffff;
    --link-color: #2e7d32;
}

[data-theme="dark"] {
    /* Dark Mode */
    --background-color: #121212;
    --container-bg: #1e1e1e;
    --primary-color: #81c784;
    --primary-hover-color: #a5d6a7;
    --text-color: #e0e0e0;
    --secondary-text: #bbb;
    --border-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --number-bg: #2e3b2e;
    --input-bg: #2d2d2d;
    --nav-bg: #1e1e1e;
    --link-color: #81c784;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', 'Malgun Gothic', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
    line-height: 1.7;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Navbar */
.navbar {
    background-color: var(--nav-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0.8rem 0;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1.5rem;
}

.nav-logo {
    font-weight: 800;
    font-size: 1.4rem;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-menu {
    list-style: none;
    display: flex;
    gap: 2rem;
    margin: 0;
    padding: 0;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-size: 0.95rem;
    font-weight: 600;
    transition: color 0.2s;
}

.nav-menu a:hover, .nav-menu a.active {
    color: var(--primary-color);
}

/* Main Container */
.container {
    background-color: var(--container-bg);
    margin: 3rem auto;
    padding: 3rem;
    border-radius: 1.5rem;
    box-shadow: 0 15px 40px var(--shadow-color);
    width: 90%;
    max-width: 850px;
    flex: 1; /* Pushes footer down */
}

h1 {
    color: var(--primary-color);
    font-size: 2.2rem;
    margin-bottom: 1.5rem;
    text-align: center;
    letter-spacing: -0.5px;
}

h2 {
    font-size: 1.6rem;
    margin-top: 2.5rem;
    margin-bottom: 1.2rem;
    color: var(--text-color);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.3rem;
    margin-top: 1.5rem;
    color: var(--primary-color);
}

p, li {
    color: var(--secondary-text);
    font-size: 1.05rem;
    margin-bottom: 1rem;
}

ul {
    padding-left: 1.5rem;
}

a {
    color: var(--link-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Generator Specific */
.generator-section {
    text-align: center;
    padding: 2rem 0;
}

.generator-desc {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 2rem;
}

#generate-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 1.2rem 4rem;
    border-radius: 4rem;
    font-size: 1.2rem;
    font-weight: 800;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(46, 125, 50, 0.25);
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

#generate-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 25px rgba(46, 125, 50, 0.35);
    background-color: var(--primary-hover-color);
}

#lotto-numbers-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
    justify-items: center;
}

lotto-numbers {
    display: block;
    width: 100%;
    max-width: 350px;
    background-color: var(--container-bg);
    padding: 1.2rem 0.5rem;
    border-radius: 1rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 8px var(--shadow-color);
    transition: transform 0.2s ease;
    white-space: nowrap; /* 숫자가 한 줄에 나오도록 강제 */
    overflow: hidden;
}

.quantity-selector {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

#reset-btn {
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    border: 1px solid #ff5252;
    background-color: transparent;
    color: #ff5252;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

#reset-btn:hover {
    background-color: #ff5252;
    color: white;
}

/* Contact Form */
.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-weight: 600; color: var(--text-color); }
.form-group input, .form-group textarea {
    width: 100%; padding: 1rem; border-radius: 0.8rem;
    border: 1px solid var(--border-color); background-color: var(--input-bg);
    color: var(--text-color); box-sizing: border-box; font-family: inherit; font-size: 1rem;
}
.form-group textarea { height: 150px; resize: vertical; }
.submit-btn {
    background-color: var(--text-color); color: var(--container-bg); padding: 1rem;
    border-radius: 0.8rem; font-weight: 700; width: 100%; border: none; cursor: pointer;
    font-size: 1.1rem; transition: opacity 0.2s;
}
.submit-btn:hover { opacity: 0.9; }

/* Footer */
.footer {
    background-color: var(--container-bg);
    padding: 3rem 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
    margin-top: 3rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.footer-links a {
    color: var(--secondary-text);
    font-size: 0.9rem;
    font-weight: 500;
}

.copyright {
    color: var(--secondary-text);
    font-size: 0.85rem;
    opacity: 0.8;
}

/* Theme Toggle */
#theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
}

/* Mobile */
@media (max-width: 768px) {
    .nav-menu { display: none; } /* Mobile Menu would need JS, keeping simple for now */
    .container { padding: 1.5rem; margin: 1.5rem auto; width: 92%; }
    lotto-numbers { gap: 0.5rem; }
    h1 { font-size: 1.8rem; }
}