/* ============================================
   CSS 변수 정의 (다크/라이트 모드)
   ============================================ */
:root {
    /* 라이트 모드 색상 */
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8f9fa;
    --color-bg-tertiary: #e9ecef;
    --color-text-primary: #1a1a1a;
    --color-text-secondary: #6c757d;
    --color-text-tertiary: #adb5bd;
    --color-accent: #0066cc;
    --color-accent-hover: #0052a3;
    --color-border: #dee2e6;
    --color-card-bg: #ffffff;
    --color-card-border: #e9ecef;
    --color-shadow: rgba(0, 0, 0, 0.08);
    --color-shadow-hover: rgba(0, 0, 0, 0.12);
    
    /* 타이포그래피 */
    --font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans KR', 'Malgun Gothic', sans-serif;
    --font-family-heading: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans KR', 'Malgun Gothic', sans-serif;
    
    /* 간격 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* 전환 효과 */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 레이아웃 */
    --container-max-width: 1280px;
    --header-height: 70px;
}

[data-theme="dark"] {
    /* 다크 모드 색상 */
    --color-bg-primary: #0a0a0a;
    --color-bg-secondary: #141414;
    --color-bg-tertiary: #1f1f1f;
    --color-text-primary: #f5f5f5;
    --color-text-secondary: #b0b0b0;
    --color-text-tertiary: #707070;
    --color-accent: #4a9eff;
    --color-accent-hover: #6bb0ff;
    --color-border: #2a2a2a;
    --color-card-bg: #141414;
    --color-card-border: #2a2a2a;
    --color-shadow: rgba(0, 0, 0, 0.3);
    --color-shadow-hover: rgba(0, 0, 0, 0.5);
}

/* ============================================
   기본 스타일 리셋
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-base);
    font-size: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    transition: background-color var(--transition-base), color var(--transition-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent);
}

button {
    background: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
    padding: 0;
}

ul, ol {
    list-style: none;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text-primary);
}

/* ============================================
   헤더
   ============================================ */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--color-bg-primary);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.95);
    transition: background-color var(--transition-base), border-color var(--transition-base);
}

[data-theme="dark"] .header {
    background-color: rgba(10, 10, 10, 0.95);
}

.header-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-lg);
}

.logo a {
    display: flex;
    align-items: center;
    text-decoration: none;
}

.logo-img {
    height: 16px;
    width: auto;
    transition: opacity var(--transition-base);
}

.logo a:hover .logo-img {
    opacity: 0.8;
}

/* 네비게이션 */
.main-nav {
    flex: 1;
    display: flex;
    justify-content: center;
}

/* 모바일 태그 영역 (PC에서는 숨김) */
.mobile-tags {
    display: none;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-menu a {
    font-size: clamp(0.875rem, 0.8rem + 0.25vw, 1rem);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    color: var(--color-text-secondary);
    position: relative;
    transition: color var(--transition-fast);
}

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

.nav-menu a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: var(--spacing-sm);
    right: var(--spacing-sm);
    height: 2px;
    background-color: var(--color-accent);
}

/* 모바일 메뉴 토글 */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 28px;
    height: 28px;
    padding: 0;
    justify-content: center;
    align-items: center;
    z-index: 1001;
    position: relative;
}

.mobile-menu-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--color-text-primary);
    transition: transform var(--transition-base), opacity var(--transition-base);
    transform-origin: center;
    position: absolute;
}

.mobile-menu-toggle span:nth-child(1) {
    top: 8px;
}

.mobile-menu-toggle span:nth-child(2) {
    top: 13px;
}

.mobile-menu-toggle span:nth-child(3) {
    top: 18px;
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(1) {
    top: 13px;
    transform: rotate(45deg);
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(3) {
    top: 13px;
    transform: rotate(-45deg);
}

/* 헤더 액션 버튼 */
.header-actions {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.search-btn,
.theme-toggle {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    color: var(--color-text-secondary);
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.search-btn:hover,
.theme-toggle:hover {
    background-color: var(--color-bg-secondary);
    color: var(--color-text-primary);
}

.theme-toggle svg {
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.theme-toggle .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: block;
}

/* ============================================
   검색 오버레이
   ============================================ */
.search-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(4px);
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.search-overlay.active {
    display: flex;
    opacity: 1;
}

.search-container {
    width: 90%;
    max-width: 600px;
    position: relative;
}

.search-input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: clamp(1rem, 1.5vw, 1.25rem);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    border: 2px solid var(--color-border);
    border-radius: 12px;
    outline: none;
    transition: border-color var(--transition-fast);
}

.search-input:focus {
    border-color: var(--color-accent);
}

.search-close {
    position: absolute;
    right: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    font-size: 2rem;
    color: var(--color-text-secondary);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.search-close:hover {
    background-color: var(--color-bg-secondary);
    color: var(--color-text-primary);
}

/* ============================================
   메인 콘텐츠
   ============================================ */
.main-content {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: var(--spacing-xl);
}

/* ============================================
   히어로 섹션
   ============================================ */
.hero-section {
    grid-column: 1 / -1;
    margin-bottom: var(--spacing-xl);
}

.hero-article {
    position: relative;
    border-radius: 16px;
    overflow: hidden;
    background-color: var(--color-card-bg);
    border: 1px solid var(--color-card-border);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.hero-article:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px var(--color-shadow-hover);
}

.hero-image-wrapper {
    position: relative;
    width: 100%;
    padding-top: 100%;
    overflow: hidden;
    background-color: var(--color-bg-tertiary);
}

.hero-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.hero-article:hover .hero-image {
    transform: scale(1.05);
}

.hero-badge {
    position: absolute;
    top: var(--spacing-md);
    left: var(--spacing-md);
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--color-accent);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 6px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.hero-content {
    padding: var(--spacing-xl);
}

.hero-category {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--color-bg-secondary);
    color: var(--color-accent);
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 6px;
    margin-bottom: var(--spacing-md);
}

.hero-title {
    font-size: clamp(1.75rem, 3vw + 0.5rem, 3rem);
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
    letter-spacing: -0.02em;
}

.hero-excerpt {
    font-size: clamp(1rem, 1.2vw + 0.5rem, 1.25rem);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.7;
}

.hero-meta {
    display: flex;
    gap: var(--spacing-md);
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
}

/* ============================================
   섹션 헤더
   ============================================ */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: clamp(1.5rem, 2vw + 0.5rem, 2rem);
    font-weight: 800;
    letter-spacing: -0.02em;
}

.section-more {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-accent);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 6px;
    transition: background-color var(--transition-fast);
}

.section-more:hover {
    background-color: var(--color-bg-secondary);
}

/* ============================================
   최신 뉴스 섹션 (Bento Grid)
   ============================================ */
.latest-section {
    grid-column: 1;
}

.bento-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.bento-grid .featured-card {
    grid-column: span 2;
    grid-row: span 2;
}

.news-card {
    background-color: var(--color-card-bg);
    border: 1px solid var(--color-card-border);
    border-radius: 12px;
    overflow: hidden;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
    display: flex;
    flex-direction: column;
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px var(--color-shadow-hover);
}

.card-image-wrapper {
    position: relative;
    width: 100%;
    padding-top: 100%;
    overflow: hidden;
    background-color: var(--color-bg-tertiary);
}

.featured-card .card-image-wrapper {
    padding-top: 100%;
}

.card-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.news-card:hover .card-image {
    transform: scale(1.05);
}

.card-category {
    display: inline-block;
    padding: 2px var(--spacing-xs);
    background-color: var(--color-bg-secondary);
    color: var(--color-accent);
    font-size: 0.7rem;
    font-weight: 600;
    border-radius: 4px;
    margin-right: -15px;
    margin-top: -1px;
    vertical-align: middle;
}

.card-content {
    padding: var(--spacing-md);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-title {
    font-size: clamp(1rem, 1.2vw + 0.5rem, 1.25rem);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.featured-card .card-title {
    font-size: clamp(1.25rem, 1.5vw + 0.5rem, 1.75rem);
    -webkit-line-clamp: 3;
}

.card-excerpt {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
    flex: 1;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.featured-card .card-excerpt {
    font-size: 1rem;
    -webkit-line-clamp: 4;
}

.card-meta {
    display: flex;
    justify-content: flex-start;
    gap: var(--spacing-md);
    font-size: 0.75rem;
    color: var(--color-text-tertiary);
    margin-top: auto;
}

/* ============================================
   카테고리 섹션
   ============================================ */
.category-section {
    grid-column: 1;
    margin-top: var(--spacing-2xl);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.category-card {
    background-color: var(--color-card-bg);
    border: 1px solid var(--color-card-border);
    border-radius: 12px;
    overflow: hidden;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.category-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px var(--color-shadow-hover);
}

.category-card-image {
    width: 100%;
    padding-top: 100%;
    position: relative;
    overflow: hidden;
    background-color: var(--color-bg-tertiary);
}

.category-card-image img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.category-card:hover .category-card-image img {
    transform: scale(1.05);
}

.category-card-content {
    padding: var(--spacing-md);
}

.category-card-title {
    font-size: clamp(1rem, 1.1vw + 0.5rem, 1.125rem);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.category-card-excerpt {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.category-card-date {
    font-size: 0.75rem;
    color: var(--color-text-tertiary);
}

/* ============================================
   사이드바
   ============================================ */
.sidebar {
    grid-column: 2;
    grid-row: 1 / -1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    position: sticky;
    top: calc(var(--header-height) + var(--spacing-md));
    align-self: flex-start;
    height: fit-content;
}

.sidebar-widget {
    background-color: var(--color-card-bg);
    border: 1px solid var(--color-card-border);
    border-radius: 12px;
    padding: var(--spacing-lg);
}

.widget-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-border);
}

.popular-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.popular-item {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border);
}

.popular-item:last-child {
    border-bottom: none;
}

.popular-link {
    display: flex;
    gap: var(--spacing-sm);
    align-items: flex-start;
    transition: color var(--transition-fast);
}

.popular-link:hover {
    color: var(--color-accent);
}

.popular-rank {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    background-color: var(--color-bg-secondary);
    color: var(--color-accent);
    font-size: 0.875rem;
    font-weight: 700;
    border-radius: 4px;
    flex-shrink: 0;
}

.popular-text {
    font-size: 0.875rem;
    line-height: 1.5;
    flex: 1;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tag {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--color-bg-secondary);
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    border-radius: 6px;
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.tag:hover {
    background-color: var(--color-accent);
    color: white;
}

/* ============================================
   푸터
   ============================================ */
.footer {
    margin-top: var(--spacing-2xl);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
    background-color: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border);
}

.footer-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section {
    display: flex;
    flex-direction: column;
}

.footer-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.footer-description {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.footer-links a {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--color-accent);
}

.footer-bottom {
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.footer-copyright {
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
}

/* ============================================
   반응형 디자인
   ============================================ */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        display: none;
    }
    
    .bento-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .bento-grid .featured-card {
        grid-column: span 2;
    }
    
    .category-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-container {
        padding: 0 var(--spacing-sm);
        position: relative;
    }
    
    .main-nav {
        order: 3;
        width: 100%;
        position: absolute;
        top: 100%;
        left: 0;
        background-color: var(--color-bg-primary);
        border-top: 1px solid var(--color-border);
        max-height: 0;
        overflow: hidden;
        transition: max-height var(--transition-base);
        z-index: 1000;
    }
    
    .main-nav.active {
        max-height: 100vh;
        display: flex;
        flex-direction: column;
    }
    
    .nav-menu {
        flex-direction: column;
        padding: var(--spacing-md);
        gap: 0;
        align-items: flex-start;
        width: 100%;
    }
    
    .nav-menu li {
        width: 100%;
    }
    
    .nav-menu a {
        display: block;
        padding: var(--spacing-sm);
        border-bottom: 1px solid var(--color-border);
        text-align: left;
    }
    
    .nav-menu a.active::after {
        display: none;
    }
    
    /* 모바일 태그 영역 - 사이드바와 동일한 디자인 */
    .mobile-tags {
        display: flex;
        flex-direction: column;
        margin-top: auto;
        padding: var(--spacing-lg);
        background-color: var(--color-card-bg);
        border-top: 1px solid var(--color-card-border);
    }
    
    .mobile-tags-title {
        font-size: 1.125rem;
        font-weight: 700;
        margin-bottom: var(--spacing-md);
        padding-bottom: var(--spacing-sm);
        border-bottom: 2px solid var(--color-border);
        color: var(--color-text-primary);
    }
    
    .mobile-tags .tag-cloud {
        display: flex;
        flex-wrap: wrap;
        gap: var(--spacing-xs);
    }
    
    .mobile-tags .tag {
        display: inline-block;
        padding: var(--spacing-xs) var(--spacing-sm);
        background-color: var(--color-bg-secondary);
        color: var(--color-text-secondary);
        font-size: 0.875rem;
        border-radius: 6px;
        transition: background-color var(--transition-fast), color var(--transition-fast);
    }
    
    .mobile-tags .tag:hover {
        background-color: var(--color-accent);
        color: white;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .main-content {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .bento-grid {
        grid-template-columns: 1fr;
    }
    
    .bento-grid .featured-card {
        grid-column: span 1;
        grid-row: span 1;
    }
    
    .category-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .hero-content {
        padding: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .header-container {
        gap: var(--spacing-sm);
    }
    
    .logo a {
        font-size: 1.25rem;
    }
    
    .hero-content {
        padding: var(--spacing-sm);
    }
    
    .card-content,
    .category-card-content {
        padding: var(--spacing-sm);
    }
}

/* ============================================
   접근성 개선
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 포커스 스타일 */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
    border-radius: 4px;
}

/* 스크린 리더 전용 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}