:root {
    --bg-color: #fcfaf7;
    --text-color: #2d3436;
    --card-bg: #ffffff;
    --ad-bg: #f8f9fa;
    --primary: #d4af37;
    --primary-light: #fdf2f2;
    --accent: #e84393;
    --border: #ececec;
    --hero-bg: #ffffff;
}

[data-theme="dark"] {
    --bg-color: #121212;
    --text-color: #e0e0e0;
    --card-bg: #1e1e1e;
    --ad-bg: #252525;
    --primary: #f1c40f;
    --border: #333333;
    --hero-bg: #1e1e1e;
}

body {
    margin: 0;
    background: var(--bg-color);
    color: var(--text-color);
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    line-height: 1.7;
}

/* 네비게이션 */
.navbar {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
    text-decoration: none;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    margin-left: 1.5rem;
    font-weight: 600;
}

/* 히어로 */
.hero-section {
    text-align: center;
    padding: 5rem 1.5rem;
    background: var(--hero-bg);
    border-bottom: 1px solid var(--border);
}

.header {
    font-size: 2.8rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.subtitle {
    color: #636e72;
    margin-bottom: 3rem;
}

/* 검색 */
.search-container {
    max-width: 600px;
    margin: 0 auto;
}

#term-search {
    width: 100%;
    padding: 1rem 1.5rem;
    border-radius: 30px;
    border: 2px solid var(--border);
    background: var(--card-bg);
    color: var(--text-color);
    font-size: 1.1rem;
    outline: none;
}

#term-search:focus {
    border-color: var(--primary);
}

/* 카테고리 그룹 */
.category-group {
    margin-bottom: 4rem;
}

.category-title {
    font-size: 1.8rem;
    font-weight: 800;
    margin-bottom: 2rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--primary);
    display: inline-block;
}

/* 용어 카드 그리드 */
.term-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.term-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2rem;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
}

.term-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}

.term-header h3 {
    margin: 0 0 1rem;
    font-size: 1.4rem;
    color: var(--primary);
}

.term-body .description {
    font-size: 1rem;
    color: var(--text-color);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.related-box {
    background: var(--ad-bg);
    padding: 1rem;
    border-radius: 0.8rem;
    font-size: 0.9rem;
}

.related-label {
    font-weight: 800;
    color: var(--accent);
    display: block;
    margin-bottom: 0.3rem;
}

.related-text {
    color: #636e72;
}

[data-theme="dark"] .related-text {
    color: #b2bec3;
}

/* 컨테이너 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

/* 광고 */
.ad-box {
    margin: 3rem auto;
    max-width: 970px;
    height: 120px;
    background: var(--ad-bg);
    border: 1px dashed var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #9ca3af;
    border-radius: 1rem;
}

/* 푸터 */
.footer {
    padding: 4rem 0;
    background: var(--card-bg);
    border-top: 1px solid var(--border);
    margin-top: 5rem;
    text-align: center;
}

.footer-links {
    margin-top: 1rem;
}

.footer-links a {
    margin: 0 1rem;
    color: var(--text-color);
    text-decoration: none;
}

.theme-toggle {
    background: var(--card-bg);
    border: 1px solid var(--border);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 10px;
    cursor: pointer;
}

@media (max-width: 768px) {
    .term-grid { grid-template-columns: 1fr; }
    .header { font-size: 2rem; }
}