/* TechDics IT 용어 사전의 전체 스타일 — CSS Variables 기반 라이트/다크 테마 */

/* ════════════════════════════════════════════
   1. CSS Custom Properties (테마 변수)
════════════════════════════════════════════ */
:root {
  /* 브랜드 컬러 */
  --primary:        #2563eb;
  --primary-hover:  #1d4ed8;
  --primary-light:  #dbeafe;
  --primary-muted:  #eff6ff;

  /* 카테고리 컬러 */
  --cat-ai:          #7c3aed;
  --cat-ai-bg:       #f5f3ff;
  --cat-network:     #2563eb;
  --cat-network-bg:  #eff6ff;
  --cat-cloud:       #0891b2;
  --cat-cloud-bg:    #ecfeff;
  --cat-dev:         #059669;
  --cat-dev-bg:      #ecfdf5;
  --cat-security:    #dc2626;
  --cat-security-bg: #fef2f2;
  --cat-data:        #d97706;
  --cat-data-bg:     #fffbeb;
  --cat-engineering: #475569;
  --cat-engineering-bg: #f8fafc;

  /* 난이도 컬러 */
  --diff-beginner:     #059669;
  --diff-beginner-bg:  #d1fae5;
  --diff-intermediate: #d97706;
  --diff-intermediate-bg: #fef3c7;
  --diff-advanced:     #dc2626;
  --diff-advanced-bg:  #fee2e2;

  /* 배경 & 표면 */
  --bg:        #f1f5f9;
  --surface:   #ffffff;
  --surface2:  #f8fafc;
  --surface3:  #f1f5f9;

  /* 텍스트 */
  --text:         #0f172a;
  --text-secondary: #475569;
  --text-muted:   #94a3b8;

  /* 테두리 & 그림자 */
  --border:       #e2e8f0;
  --border-focus: #93c5fd;
  --shadow-sm:    0 1px 2px rgba(0,0,0,.06);
  --shadow:       0 2px 8px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md:    0 4px 16px rgba(0,0,0,.1),  0 2px 4px rgba(0,0,0,.06);
  --shadow-lg:    0 20px 40px rgba(0,0,0,.15);

  /* 레이아웃 */
  --radius-sm:  6px;
  --radius:     12px;
  --radius-lg:  16px;
  --max-width:  1200px;

  /* 전환 */
  --transition: 180ms ease;
}

/* 다크 모드 변수 오버라이드 */
[data-theme="dark"] {
  --bg:        #0f172a;
  --surface:   #1e293b;
  --surface2:  #1e293b;
  --surface3:  #0f172a;

  --text:           #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted:     #64748b;

  --border:       #334155;
  --border-focus: #3b82f6;
  --shadow-sm:    0 1px 2px rgba(0,0,0,.3);
  --shadow:       0 2px 8px rgba(0,0,0,.3), 0 1px 2px rgba(0,0,0,.2);
  --shadow-md:    0 4px 16px rgba(0,0,0,.4), 0 2px 4px rgba(0,0,0,.2);
  --shadow-lg:    0 20px 40px rgba(0,0,0,.5);

  --primary-light: #1e3a8a;
  --primary-muted: #172554;

  --cat-ai-bg:          #2e1065;
  --cat-network-bg:     #172554;
  --cat-cloud-bg:       #083344;
  --cat-dev-bg:         #052e16;
  --cat-security-bg:    #450a0a;
  --cat-data-bg:        #451a03;
  --cat-engineering-bg: #1e293b;

  --diff-beginner-bg:     #052e16;
  --diff-intermediate-bg: #451a03;
  --diff-advanced-bg:     #450a0a;
}


/* ════════════════════════════════════════════
   2. Reset & Base
════════════════════════════════════════════ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Noto Sans KR", "Apple SD Gothic Neo", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 15px;
  transition: background var(--transition), color var(--transition);
  min-height: 100vh;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

button { cursor: pointer; border: none; background: none; font: inherit; }

input, select {
  font: inherit;
  color: var(--text);
}

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

.hidden { display: none !important; }


/* ════════════════════════════════════════════
   3. Header
════════════════════════════════════════════ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background var(--transition), border-color var(--transition);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

/* 로고 */
.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  flex-shrink: 0;
}

.logo-icon { font-size: 1.4rem; }

.logo-text {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: -.02em;
}

.logo-sub {
  font-size: .72rem;
  color: var(--text-muted);
  border-left: 1px solid var(--border);
  padding-left: 8px;
  margin-left: 4px;
  display: none;
}

@media (min-width: 480px) { .logo-sub { display: block; } }

/* 헤더 버튼 */
.header-actions { display: flex; align-items: center; gap: 8px; }

.btn-icon {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: .85rem;
  font-weight: 600;
  transition: background var(--transition), color var(--transition), transform .1s;
  position: relative;
}

.btn-icon:hover {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary);
}

.btn-icon:active { transform: scale(.96); }
.btn-icon .icon  { font-size: 1rem; }
.btn-label { display: none; }

@media (min-width: 520px) { .btn-label { display: inline; } }

/* 즐겨찾기 개수 뱃지 */
.badge {
  background: var(--primary);
  color: white;
  font-size: .65rem;
  font-weight: 700;
  border-radius: 99px;
  min-width: 18px;
  height: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 4px;
  position: absolute;
  top: 2px;
  right: 2px;
  pointer-events: none;
}

/* 즐겨찾기 모드 활성화 */
.btn-icon.active {
  background: #fef9c3;
  color: #d97706;
  border-color: #fcd34d;
}

[data-theme="dark"] .btn-icon.active {
  background: #451a03;
  color: #fcd34d;
  border-color: #92400e;
}


/* ════════════════════════════════════════════
   4. Hero & 검색창
════════════════════════════════════════════ */
.hero {
  background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 55%, #7c3aed 100%);
  padding: 48px 20px 52px;
  text-align: center;
  color: white;
}

.hero-inner { max-width: 640px; margin: 0 auto; }

.hero-title {
  font-size: clamp(1.5rem, 3.5vw, 2.2rem);
  font-weight: 800;
  letter-spacing: -.03em;
  margin-bottom: 10px;
}

.hero-desc {
  font-size: .95rem;
  opacity: .8;
  margin-bottom: 28px;
}

/* 검색 래퍼 */
.search-wrap {
  position: relative;
  display: flex;
  align-items: center;
  background: white;
  border-radius: 99px;
  box-shadow: 0 4px 20px rgba(0,0,0,.2);
  overflow: hidden;
  transition: box-shadow .2s;
}

.search-wrap:focus-within {
  box-shadow: 0 4px 20px rgba(0,0,0,.2), 0 0 0 3px rgba(147,197,253,.6);
}

.search-icon {
  padding: 0 6px 0 18px;
  font-size: 1.1rem;
  flex-shrink: 0;
  pointer-events: none;
}

.search-input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  padding: 14px 8px;
  font-size: 1rem;
  color: #0f172a;
}

.search-input::placeholder { color: #94a3b8; }

/* ✕ 지우기 버튼 */
.search-clear {
  padding: 0 16px 0 8px;
  color: #94a3b8;
  font-size: 1rem;
  background: transparent;
  flex-shrink: 0;
  transition: color .15s;
}

.search-clear:hover { color: #475569; }


/* ════════════════════════════════════════════
   5. 메인 레이아웃
════════════════════════════════════════════ */
.main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px 80px;
}


/* ════════════════════════════════════════════
   6. 카테고리 탭
════════════════════════════════════════════ */
.tabs-wrap {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding: 20px 0 4px;
  scrollbar-width: none;        /* Firefox 64+ */
  -ms-overflow-style: none;     /* IE/Edge */
}

.tabs-wrap::-webkit-scrollbar { display: none; }

.tab {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 8px 16px;
  border-radius: 99px;
  border: 1.5px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  font-size: .85rem;
  font-weight: 600;
  white-space: nowrap;
  transition: all var(--transition);
  flex-shrink: 0;
}

.tab:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-muted);
}

.tab.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
  box-shadow: 0 2px 8px rgba(37,99,235,.35);
}


/* ════════════════════════════════════════════
   7. 결과 정보 바
════════════════════════════════════════════ */
.results-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0 12px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 20px;
  gap: 12px;
}

.results-count {
  font-size: .875rem;
  color: var(--text-muted);
}

.results-count strong { color: var(--text); font-weight: 700; }

.sort-select {
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  font-size: .82rem;
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition);
}

.sort-select:focus { border-color: var(--primary); }


/* ════════════════════════════════════════════
   8. 카드 그리드
════════════════════════════════════════════ */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}

/* ── 개별 카드 ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 18px 14px;
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: transform .15s, box-shadow .15s, border-color .15s;
  display: flex;
  flex-direction: column;
  gap: 8px;
  position: relative;
  overflow: hidden;
  animation: fadeInUp .25s ease both;
}

.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--card-accent, var(--primary));
  border-radius: var(--radius) var(--radius) 0 0;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--card-accent, var(--primary));
}

/* 카테고리별 강조색 */
.card[data-category="ai"]          { --card-accent: var(--cat-ai); }
.card[data-category="network"]     { --card-accent: var(--cat-network); }
.card[data-category="cloud"]       { --card-accent: var(--cat-cloud); }
.card[data-category="dev"]         { --card-accent: var(--cat-dev); }
.card[data-category="security"]    { --card-accent: var(--cat-security); }
.card[data-category="data"]        { --card-accent: var(--cat-data); }
.card[data-category="engineering"] { --card-accent: var(--cat-engineering); }

/* 카드 헤더 */
.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
}

.card-title-wrap { flex: 1; min-width: 0; }

.card-term {
  font-size: 1rem;
  font-weight: 800;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.card-term-ko {
  font-size: .75rem;
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 2px;
}

/* 즐겨찾기 버튼 (카드) */
.card-favorite {
  font-size: 1.1rem;
  line-height: 1;
  padding: 4px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  transition: color .15s, transform .15s;
  flex-shrink: 0;
}

.card-favorite:hover { color: #f59e0b; transform: scale(1.2); }
.card-favorite.active { color: #f59e0b; }

/* 카드 정의 */
.card-definition {
  font-size: .845rem;
  color: var(--text-secondary);
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* 카드 푸터 */
.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  gap: 6px;
}

/* 카테고리 뱃지 */
.category-badge {
  font-size: .7rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 99px;
  white-space: nowrap;
  color: white;
  background: var(--cat-color, var(--primary));
}

.category-badge[data-cat="ai"]          { --cat-color: var(--cat-ai); }
.category-badge[data-cat="network"]     { --cat-color: var(--cat-network); }
.category-badge[data-cat="cloud"]       { --cat-color: var(--cat-cloud); }
.category-badge[data-cat="dev"]         { --cat-color: var(--cat-dev); }
.category-badge[data-cat="security"]    { --cat-color: var(--cat-security); }
.category-badge[data-cat="data"]        { --cat-color: var(--cat-data); }
.category-badge[data-cat="engineering"] { --cat-color: var(--cat-engineering); }

/* 난이도 뱃지 */
.difficulty-badge {
  font-size: .7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 99px;
  white-space: nowrap;
}

.difficulty-badge[data-level="beginner"] {
  background: var(--diff-beginner-bg);
  color: var(--diff-beginner);
}

.difficulty-badge[data-level="intermediate"] {
  background: var(--diff-intermediate-bg);
  color: var(--diff-intermediate);
}

.difficulty-badge[data-level="advanced"] {
  background: var(--diff-advanced-bg);
  color: var(--diff-advanced);
}

/* 검색어 하이라이트 */
.highlight {
  background: #fef08a;
  color: #713f12;
  border-radius: 3px;
  padding: 0 2px;
}

[data-theme="dark"] .highlight {
  background: #713f12;
  color: #fef08a;
}


/* ════════════════════════════════════════════
   9. Empty State
════════════════════════════════════════════ */
.empty-state {
  text-align: center;
  padding: 80px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.empty-icon   { font-size: 3rem; opacity: .5; }
.empty-title  { font-size: 1.1rem; font-weight: 700; color: var(--text); }
.empty-desc   { font-size: .9rem; color: var(--text-muted); }


/* ════════════════════════════════════════════
   10. 모달
════════════════════════════════════════════ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .55);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 0;
  animation: fadeIn .2s ease;
}

@media (min-width: 600px) {
  .modal-overlay {
    align-items: center;
    padding: 20px;
  }
}

/* 모달 박스 */
.modal {
  background: var(--surface);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  width: 100%;
  max-width: 560px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  position: relative;
  display: flex;
  flex-direction: column;
  animation: slideUp .25s cubic-bezier(.32,.72,0,1);
}

@media (min-width: 600px) {
  .modal {
    border-radius: var(--radius-lg);
    animation: scaleIn .2s cubic-bezier(.32,.72,0,1);
  }
}

/* 모달 닫기 버튼 */
.modal-close {
  position: absolute;
  top: 14px; right: 14px;
  width: 32px; height: 32px;
  border-radius: 50%;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: .9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition), color var(--transition);
  z-index: 1;
}

.modal-close:hover { background: var(--border); color: var(--text); }

/* 모달 헤더 */
.modal-header {
  padding: 24px 24px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.modal-term-wrap { padding-right: 36px; }

.modal-term {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -.02em;
}

.modal-term-ko {
  font-size: .9rem;
  color: var(--text-muted);
  display: block;
  margin-top: 4px;
}

.modal-meta {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* 모달 본문 */
.modal-body { padding: 20px 24px; display: flex; flex-direction: column; gap: 20px; }

.modal-definition {
  font-size: .96rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.modal-section { display: flex; flex-direction: column; gap: 10px; }

.modal-section-title {
  font-size: .78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--text-muted);
}

/* 태그 목록 */
.tags-list { display: flex; flex-wrap: wrap; gap: 6px; }

.tag-chip {
  padding: 4px 10px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: .78rem;
  color: var(--text-secondary);
}

/* 관련 용어 */
.related-list { display: flex; flex-wrap: wrap; gap: 8px; }

.related-link {
  padding: 5px 12px;
  background: var(--primary-muted);
  border: 1px solid var(--primary-light);
  border-radius: 99px;
  font-size: .82rem;
  font-weight: 600;
  color: var(--primary);
  transition: background var(--transition), transform .1s;
  cursor: pointer;
}

.related-link:hover {
  background: var(--primary-light);
  transform: scale(1.04);
  text-decoration: none;
}

/* 모달 푸터 */
.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
}

.btn-favorite-modal {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 99px;
  border: 1.5px solid var(--border);
  background: var(--surface2);
  color: var(--text-secondary);
  font-size: .9rem;
  font-weight: 600;
  transition: all var(--transition);
}

.btn-favorite-modal:hover {
  border-color: #f59e0b;
  color: #d97706;
  background: #fffbeb;
}

.btn-favorite-modal.active {
  border-color: #f59e0b;
  color: #d97706;
  background: #fef9c3;
}

[data-theme="dark"] .btn-favorite-modal.active {
  background: #451a03;
  color: #fcd34d;
  border-color: #92400e;
}


/* ════════════════════════════════════════════
   11. 로딩 오버레이
════════════════════════════════════════════ */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: var(--bg);
  z-index: 300;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  color: var(--text-muted);
  font-size: .9rem;
  transition: opacity .3s;
}

.spinner {
  width: 40px; height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin .7s linear infinite;
}


/* ════════════════════════════════════════════
   12. 토스트 알림
════════════════════════════════════════════ */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(0);
  background: #1e293b;
  color: white;
  padding: 10px 20px;
  border-radius: 99px;
  font-size: .875rem;
  font-weight: 600;
  box-shadow: var(--shadow-md);
  z-index: 400;
  white-space: nowrap;
  animation: toastIn .25s ease;
}

[data-theme="dark"] .toast {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
}

.toast.toast-out { animation: toastOut .25s ease forwards; }


/* ════════════════════════════════════════════
   13. Footer
════════════════════════════════════════════ */
.footer {
  border-top: 1px solid var(--border);
  padding: 20px;
  text-align: center;
  font-size: .8rem;
  color: var(--text-muted);
}


/* ════════════════════════════════════════════
   14. 애니메이션
════════════════════════════════════════════ */
@keyframes fadeIn    { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeInUp  { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: none; } }
@keyframes slideUp   { from { transform: translateY(100%); } to { transform: none; } }
@keyframes scaleIn   { from { opacity: 0; transform: scale(.96); } to { opacity: 1; transform: none; } }
@keyframes toastIn   { from { opacity: 0; transform: translateX(-50%) translateY(8px); } to { opacity: 1; transform: translateX(-50%) translateY(0); } }
@keyframes toastOut  { from { opacity: 1; } to { opacity: 0; transform: translateX(-50%) translateY(8px); } }
@keyframes spin      { to { transform: rotate(360deg); } }


/* ════════════════════════════════════════════
   15. 반응형
════════════════════════════════════════════ */
@media (max-width: 480px) {
  .hero { padding: 32px 16px 40px; }
  .hero-title { font-size: 1.4rem; }
  .main { padding: 0 12px 60px; }

  .cards-grid {
    grid-template-columns: 1fr;
  }

  .results-bar { flex-direction: column; align-items: flex-start; }
}

@media (min-width: 480px) and (max-width: 768px) {
  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .cards-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* 카드 애니메이션 지연 (최대 12개만) */
.card:nth-child(1)  { animation-delay: .02s; }
.card:nth-child(2)  { animation-delay: .04s; }
.card:nth-child(3)  { animation-delay: .06s; }
.card:nth-child(4)  { animation-delay: .08s; }
.card:nth-child(5)  { animation-delay: .10s; }
.card:nth-child(6)  { animation-delay: .12s; }
.card:nth-child(7)  { animation-delay: .14s; }
.card:nth-child(8)  { animation-delay: .16s; }
.card:nth-child(9)  { animation-delay: .18s; }
.card:nth-child(10) { animation-delay: .20s; }
.card:nth-child(11) { animation-delay: .22s; }
.card:nth-child(12) { animation-delay: .24s; }