/* ══════════════════════════════════════════════════════
   로미 수학 개념서 — 수능 시험지 스타일
   ══════════════════════════════════════════════════════ */

:root {
  --font-serif: 'Nanum Myeongjo', 'Batang', 'Georgia', serif;
  --font-sans:  'Nanum Gothic', 'Apple SD Gothic Neo', 'Malgun Gothic', sans-serif;
  --font-mono:  'D2Coding', 'Courier New', monospace;

  --primary:        #1c3d8c;
  --primary-light:  #edf0f8;
  --bg:             #eceae3;   /* 시험지 크림 배경 */
  --surface:        #ffffff;
  --text:           #111111;
  --text-sub:       #555555;
  --border:         #222222;
  --border-mid:     #888888;
  --border-thin:    #cccccc;

  --accent:       #1c3d8c;
  --accent-dark:  #142d6a;

  --elem-color:   #1a6b1a;
  --middle-color: #1a3a8c;
  --high-color:   #6b1a6b;
  --correct:      #1a6b1a;
  --wrong:        #8c1a1a;

  --sidebar-w:  256px;
  --header-h:   90px;
}

/* ─── Reset ─── */
* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: var(--font-serif);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.9;
}

/* ══════════════════════════════════════════════════════
   HEADER  —  시험지 상단바 스타일
   ══════════════════════════════════════════════════════ */
#header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--surface);
  border-bottom: 3px double var(--border);
  padding: 10px 24px 0;
}

.header-top {
  display: flex; align-items: center; gap: 20px;
  margin-bottom: 6px;
}

/* "로미 수학 개념서" — 제 N교시 타원형 스타일 */
.logo {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 800;
  white-space: nowrap;
  border: 2px solid var(--border);
  border-radius: 20px;
  padding: 2px 16px;
  letter-spacing: -0.3px;
  user-select: none;
}

.search-box {
  position: relative;
  flex: 1;
  max-width: 380px;
}
.search-box input {
  width: 100%;
  padding: 5px 12px;
  border: 1.5px solid var(--border);
  font-size: 0.85rem;
  outline: none;
  font-family: var(--font-sans);
  background: #fafaf7;
  border-radius: 0;
}
.search-box input:focus { border-color: var(--primary); }

.search-results {
  position: absolute; top: 100%; left: 0; right: 0;
  background: var(--surface);
  border: 1.5px solid var(--border);
  max-height: 400px; overflow-y: auto;
  z-index: 200;
  box-shadow: 3px 3px 0 rgba(0,0,0,0.12);
}
.search-results.hidden { display: none; }
.search-result-item {
  padding: 7px 12px;
  cursor: pointer;
  border-bottom: 1px solid var(--border-thin);
  font-size: 0.83rem;
  font-family: var(--font-sans);
}
.search-result-item:hover { background: var(--primary-light); }
.search-result-item .level-badge {
  font-size: 0.73rem;
  color: var(--text-sub);
  font-family: var(--font-sans);
}

/* 레벨 탭 — 시험지 과목 탭 */
.level-tabs {
  display: flex;
  gap: 0;
  overflow-x: auto;
  padding-bottom: 0;
  margin-top: 4px;
  scrollbar-width: none;
}
.level-tabs::-webkit-scrollbar { display: none; }

.level-tabs button {
  padding: 4px 13px;
  border: 1px solid var(--border-mid);
  border-bottom: none;
  border-left: none;
  background: #e5e1d8;
  cursor: pointer;
  font-size: 0.78rem;
  white-space: nowrap;
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--text-sub);
  letter-spacing: 0.3px;
  transition: background 0.12s;
}
.level-tabs button:first-child { border-left: 1px solid var(--border-mid); }
.level-tabs button:hover { background: #d8d4cb; color: var(--text); }
.level-tabs button.active {
  background: var(--surface);
  color: var(--primary);
  border-color: var(--border);
  border-bottom: 3px solid var(--surface);
  margin-bottom: -3px;
  position: relative;
  z-index: 1;
}

/* ══════════════════════════════════════════════════════
   LAYOUT
   ══════════════════════════════════════════════════════ */
.container {
  display: flex;
  margin-top: var(--header-h);
  min-height: calc(100vh - var(--header-h));
}

.sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--surface);
  border-right: 1.5px solid var(--border);
  padding: 14px 10px;
  overflow-y: auto;
  height: calc(100vh - var(--header-h));
  position: sticky;
  top: var(--header-h);
}

.content {
  flex: 1;
  padding: 32px 40px;
  max-width: 840px;
  background: var(--surface);
  border-right: 1px solid var(--border-thin);
  min-height: calc(100vh - var(--header-h) - 44px);
}

/* ══════════════════════════════════════════════════════
   SIDEBAR — 목차 스타일
   ══════════════════════════════════════════════════════ */
.tree-unit { margin-bottom: 10px; }

.tree-unit-header {
  font-weight: 700;
  font-size: 0.8rem;
  padding: 5px 8px;
  cursor: pointer;
  font-family: var(--font-sans);
  border-bottom: 1.5px solid var(--border);
  letter-spacing: 0.4px;
}
.tree-unit-header:hover { background: var(--primary-light); }

.tree-subunit { margin-left: 6px; }
.tree-subunit-header {
  font-size: 0.76rem;
  color: var(--text-sub);
  padding: 2px 8px;
  cursor: pointer;
  font-family: var(--font-sans);
  border-left: 2px solid var(--border-thin);
  margin: 2px 0;
}
.tree-subunit-header:hover {
  background: var(--primary-light);
  border-left-color: var(--primary);
}

.tree-concept {
  margin-left: 16px;
  font-size: 0.76rem;
  padding: 2px 8px;
  cursor: pointer;
  font-family: var(--font-sans);
  color: var(--text-sub);
}
.tree-concept:hover { color: var(--primary); text-decoration: underline; }
.tree-concept.active {
  color: var(--primary);
  font-weight: 700;
  background: var(--primary-light);
}

/* ══════════════════════════════════════════════════════
   CONCEPT CARD — 시험 문제지 스타일
   ══════════════════════════════════════════════════════ */
.concept-card {
  background: var(--surface);
}

/* 상단 구분선 */
.concept-card::before {
  content: '';
  display: block;
  height: 3px;
  background: var(--border);
  margin-bottom: 18px;
}

.breadcrumb {
  font-size: 0.76rem;
  color: var(--text-sub);
  margin-bottom: 10px;
  font-family: var(--font-sans);
}
.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
  font-family: var(--font-sans);
}
.breadcrumb a:hover { text-decoration: underline; }

/* 개념 제목 — 시험 번호 + 제목 스타일 */
.concept-title {
  font-family: var(--font-serif);
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 22px;
  line-height: 1.4;
  display: flex;
  align-items: baseline;
  gap: 0;
  border-bottom: 2px solid var(--border);
  padding-bottom: 10px;
}

.concept-section { margin-bottom: 22px; }

.concept-section > h3 {
  font-size: 0.75rem;
  font-weight: 700;
  margin-bottom: 6px;
  font-family: var(--font-sans);
  color: var(--text-sub);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  border-bottom: 1px solid var(--border-thin);
  padding-bottom: 3px;
}

/* 설명(definition) 박스 — 수능 보기(참고) 박스 */
.concept-section.sec-definition .content-text {
  border: 1.5px solid var(--border);
  padding: 16px 20px;
  background: #fdfcf8;
  line-height: 2.1;
  font-size: 0.93rem;
}

/* 예시 박스 */
.concept-section.sec-example .content-text {
  border: 1px solid var(--border-mid);
  padding: 12px 18px;
  background: #f7f6f1;
  line-height: 2.0;
  font-size: 0.9rem;
}

/* 추가설명 */
.concept-section.sec-extra .content-text {
  border-left: 3px solid var(--primary);
  padding: 8px 14px;
  background: var(--primary-light);
  font-size: 0.88rem;
  line-height: 1.9;
}

/* 수학 이야기 */
.concept-section.sec-story {
  border: 1px solid #c9a84c;
  border-left: 4px solid #a87820;
  background: #fdf6e3;
  border-radius: 2px;
}
.concept-section.sec-story > h3 {
  color: #7a5500;
  border-bottom-color: #c9a84c;
}
.concept-section.sec-story .content-text {
  padding: 10px 16px 4px;
  font-size: 0.9rem;
  line-height: 1.95;
  color: #2e1f00;
  font-family: var(--font-serif);
}

/* 일반 content-text (위 클래스 없을 때) */
.content-text {
  font-size: 0.93rem;
  line-height: 2.0;
  font-family: var(--font-serif);
}

/* ─── 줄 단위 텍스트 ─── */
.text-line {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  padding: 2px 0;
  border-bottom: 1px dotted var(--border-thin);
  min-height: 26px;
}
.text-line:last-child { border-bottom: none; }

.line-content {
  flex: 1;
  min-width: 200px;
  line-height: 2.0;
  font-family: var(--font-serif);
}
.line-content .list-marker {
  color: var(--primary);
  font-weight: bold;
  margin-right: 4px;
}

.line-concepts {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  flex-shrink: 0;
  align-self: center;
}
.concept-tag {
  display: inline-block;
  padding: 1px 7px;
  font-size: 0.68rem;
  background: var(--primary-light);
  color: var(--primary);
  text-decoration: none;
  white-space: nowrap;
  border: 1px solid var(--primary);
  font-family: var(--font-sans);
  transition: background 0.12s, color 0.12s;
}
.concept-tag:hover { background: var(--primary); color: #fff; }

/* ─── 마크다운 테이블 ─── */
.concept-table {
  border-collapse: collapse;
  width: 100%;
  margin: 10px 0;
  font-size: 0.86rem;
  font-family: var(--font-sans);
}
.concept-table th,
.concept-table td {
  border: 1px solid var(--border);
  padding: 6px 13px;
  text-align: center;
  line-height: 1.6;
}
.concept-table th {
  background: #e8ecf5;
  font-weight: 700;
}
.concept-table td { background: var(--surface); }

/* ─── ASCII 도형 / 코드블록 ─── */
.ascii-diagram {
  font-family: 'Consolas', 'Cascadia Code', 'D2Coding', 'Courier New', monospace;
  font-size: 0.78rem;
  background: #f7f6f0;
  border: 1px solid var(--border-mid);
  padding: 12px 16px;
  overflow-x: auto;
  overflow-y: hidden;
  white-space: pre;
  line-height: 1.6;
  margin: 10px 0;
  display: block;
  max-width: 100%;
  box-sizing: border-box;
}

/* ─── 퀴즈 버튼 ─── */
.btn-quiz {
  display: inline-block;
  padding: 8px 26px;
  background: var(--border);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 0.88rem;
  margin-top: 12px;
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: 0.5px;
  transition: background 0.12s;
}
.btn-quiz:hover { background: var(--primary); }

/* ══════════════════════════════════════════════════════
   NAV FOOTER — 하단 이전/다음
   ══════════════════════════════════════════════════════ */
#footer {
  position: fixed;
  bottom: 0;
  left: var(--sidebar-w);
  right: 0;
  background: var(--surface);
  border-top: 2px solid var(--border);
  padding: 7px 24px;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 32px;
  z-index: 50;
  font-family: var(--font-sans);
  font-size: 0.83rem;
}
#footer.hidden { display: none; }

.copyright-bar {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 49;
  text-align: center;
  padding: 5px 16px;
  background: var(--bg);
  border-top: 1px solid var(--border-thin);
  font-family: var(--font-sans);
  font-size: 0.72rem;
  color: var(--text-sub);
}
.copyright-bar a {
  color: var(--text-sub);
  text-decoration: none;
}
.copyright-bar a:hover { text-decoration: underline; }

.nav-link {
  cursor: pointer;
  color: var(--primary);
  text-decoration: none;
  font-family: var(--font-sans);
  padding: 2px 6px;
}
.nav-link:hover { text-decoration: underline; }

/* ══════════════════════════════════════════════════════
   RELATED CONCEPTS — 연결 개념
   ══════════════════════════════════════════════════════ */
.related-section {
  margin-top: 28px;
  padding-top: 14px;
  border-top: 2px solid var(--border);
}
.related-section h3 {
  font-size: 0.82rem;
  margin-bottom: 8px;
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--text-sub);
  letter-spacing: 0.5px;
}
.related-links { display: flex; flex-wrap: wrap; gap: 6px; }
.related-chip {
  padding: 3px 12px;
  background: #f0ede4;
  border: 1.5px solid var(--border);
  font-size: 0.78rem;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: background 0.12s;
}
.related-chip:hover { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ══════════════════════════════════════════════════════
   QUIZ — 확인문제 (수능 선택지 스타일)
   ══════════════════════════════════════════════════════ */
.quiz-card {
  background: var(--surface);
  padding: 22px 24px;
  margin-bottom: 18px;
  border: 1.5px solid var(--border);
}
.quiz-question {
  font-size: 0.95rem;
  margin-bottom: 16px;
  line-height: 1.9;
  font-family: var(--font-serif);
}
.quiz-choices { display: flex; flex-direction: column; gap: 7px; }
.quiz-choice {
  padding: 8px 14px;
  border: 1px solid var(--border-mid);
  cursor: pointer;
  font-size: 0.9rem;
  line-height: 1.7;
  transition: all 0.12s;
  font-family: var(--font-serif);
  display: flex;
  align-items: center;
  gap: 10px;
}
.quiz-choice:hover { border-color: var(--primary); background: var(--primary-light); }
.quiz-choice.correct {
  border-color: var(--correct);
  background: #e8f5e8;
  color: var(--correct);
  font-weight: 700;
}
.quiz-choice.wrong { border-color: var(--wrong); background: #f5e8e8; }
.quiz-choice.disabled { pointer-events: none; }

.flashcard-answer {
  padding: 12px 16px;
  background: #faf5e0;
  border: 1.5px solid #b89600;
  margin-top: 10px;
  display: none;
  font-family: var(--font-serif);
  font-size: 0.9rem;
}
.flashcard-answer.show { display: block; }
.btn-reveal {
  padding: 7px 20px;
  background: #b89600;
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 0.85rem;
  font-family: var(--font-sans);
  font-weight: 700;
}

/* ══════════════════════════════════════════════════════
   HOME — 표지 스타일
   ══════════════════════════════════════════════════════ */
.home-cover {
  border: 2px solid var(--border);
  padding: 36px 40px;
  margin-bottom: 28px;
  text-align: center;
  position: relative;
}
.home-cover-title {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 6px;
  letter-spacing: -1px;
}
.home-cover-subtitle {
  font-family: var(--font-sans);
  font-size: 0.88rem;
  color: var(--text-sub);
  margin-bottom: 24px;
}
.home-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  border-top: 1px solid var(--border-thin);
  padding-top: 18px;
  margin-top: 18px;
}
.home-stat-item {
  text-align: center;
  font-family: var(--font-sans);
}
.home-stat-num {
  display: block;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary);
  font-family: var(--font-serif);
}
.home-stat-label {
  font-size: 0.78rem;
  color: var(--text-sub);
}

/* 수준별 카드 그리드 */
.home-section-title {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--text-sub);
  border-bottom: 1.5px solid var(--border);
  padding-bottom: 6px;
  margin-bottom: 14px;
}
.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0;
  border: 1.5px solid var(--border);
  background: var(--border);
}
.home-card {
  background: var(--surface);
  padding: 22px 14px;
  text-align: center;
  cursor: pointer;
  transition: background 0.12s;
  border: 1px solid transparent;
}
.home-card:hover { background: var(--primary-light); }
.home-card .count {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
  font-family: var(--font-serif);
  line-height: 1;
}
.home-card .label {
  font-size: 0.85rem;
  color: var(--text-sub);
  margin-top: 8px;
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: 0.5px;
}

/* ══════════════════════════════════════════════════════
   LEVEL LIST VIEW
   ══════════════════════════════════════════════════════ */
.level-list-header {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 20px;
  border-bottom: 3px solid var(--border);
  padding-bottom: 10px;
}
.unit-group-title {
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-sub);
  letter-spacing: 1px;
  border-bottom: 1px solid var(--border-thin);
  padding: 8px 0 4px;
  margin: 14px 0 6px;
}
.concept-list-item {
  font-family: var(--font-sans);
  font-size: 0.83rem;
  padding: 4px 10px;
  cursor: pointer;
  color: var(--text-sub);
  border-left: 2px solid transparent;
  transition: all 0.1s;
}
.concept-list-item:hover {
  color: var(--primary);
  border-left-color: var(--primary);
  background: var(--primary-light);
}

/* ══════════════════════════════════════════════════════
   MAP GRID — 개념연결지도
   ══════════════════════════════════════════════════════ */
body.map-fullwidth .sidebar { display: none; }
body.map-fullwidth .content { max-width: none; padding: 12px; }
body.map-fullwidth #footer { left: 0; }

.map-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 6px;
  flex-wrap: wrap;
  font-family: var(--font-sans);
}
.map-toolbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.map-title {
  font-size: 0.95rem;
  font-weight: 700;
  white-space: nowrap;
  background: #2c4a2c;
  color: #fff;
  padding: 5px 18px;
  font-family: var(--font-sans);
}
.map-wrapper {
  overflow: auto;
  width: 100%;
  max-height: calc(100vh - var(--header-h) - 80px);
  border: 1.5px solid var(--border);
  background: #f5f3e6;
}
.map-table {
  border-collapse: separate;
  border-spacing: 0;
  min-width: max-content;
  font-family: var(--font-sans);
}
.map-table th, .map-table td { border: 1px solid rgba(0,0,0,0.08); }
.map-level-header {
  position: sticky; top: 0; z-index: 12;
  padding: 6px 4px; text-align: center;
  font-size: 0.72rem; font-weight: 700;
  white-space: pre-line; min-width: 72px;
  background: #d9d3b8; color: #4a4530;
  border-bottom: 2px solid #b8b098 !important;
  font-family: var(--font-sans);
}
.map-level-header.elem { background: #c9c4ad; }
.map-level-header.mid  { background: #aec4d6; }
.map-level-header.high { background: #c4b0d6; }
.map-area-header-cell {
  position: sticky; top: 0; left: 0; z-index: 15;
  min-width: 48px; background: #bfb99a;
  border-bottom: 2px solid #b8b098 !important;
}
.map-area-label {
  position: sticky; left: 0; z-index: 10;
  min-width: 48px; max-width: 48px; padding: 8px 4px;
  text-align: center; vertical-align: middle;
  color: #fff; font-weight: 700; font-size: 0.9rem;
  letter-spacing: 2px;
  font-family: var(--font-sans);
}
.map-area-label .area-label-char { display: block; line-height: 1.4; }
.map-area-label .area-label-space { display: block; height: 10px; }
.map-cell { padding: 3px 9px; vertical-align: top; min-height: 36px; }
.map-node {
  position: relative; /* ① 배지 기준점 */
  padding: 4px 8px;
  font-size: 0.75rem; text-align: center;
  border: 1.5px solid;
  white-space: nowrap;
  font-weight: 500; line-height: 1.3;
  transition: transform 0.12s, box-shadow 0.12s, opacity 0.15s, outline 0.12s;
  font-family: var(--font-sans);
}
.map-node.clickable { cursor: pointer; }
.map-node.clickable:not(.map-node-dim):hover {
  transform: scale(1.08);
  box-shadow: 2px 3px 0 rgba(0,0,0,0.25);
  z-index: 5;
}

/* ① 호버 강조 상태 */
.map-node-dim  { opacity: 0.12 !important; transform: none !important; }
.map-node-glow {
  outline: 2px solid #f59e0b !important;
  box-shadow: 0 0 6px #f59e0b88 !important;
}

/* ③ 경로 강조 상태 */
.map-node-active {
  outline: 3px solid #f97316 !important;
  box-shadow: 0 0 10px #f9731688 !important;
  z-index: 6; position: relative;
}
.map-node-ancestor {
  outline: 2px solid #3b82f6 !important;
  box-shadow: 0 0 7px #3b82f680 !important;
}
.map-node-descendant {
  outline: 2px solid #22c55e !important;
  box-shadow: 0 0 7px #22c55e80 !important;
}

/* 맵 노드 개념 팝업 */
.map-concept-popup {
  position: absolute;
  z-index: 100;
  background: #fff;
  border: 1.5px solid var(--border);
  box-shadow: 3px 3px 0 rgba(0,0,0,0.18);
  min-width: 160px;
  max-width: 260px;
  font-family: var(--font-sans);
  font-size: 0.78rem;
}
.map-concept-popup .popup-header {
  padding: 5px 10px;
  background: var(--border);
  color: #fff;
  font-weight: 700;
  font-size: 0.8rem;
}
.map-concept-popup .popup-item {
  padding: 6px 10px;
  cursor: pointer;
  border-bottom: 1px solid var(--border-thin);
  color: var(--text);
  line-height: 1.3;
  transition: background 0.1s;
}
.map-concept-popup .popup-item:last-child { border-bottom: none; }
.map-concept-popup .popup-item:hover { background: var(--primary-light); }

/* ④ 줌 컨트롤 */
.map-zoom-ctrl {
  display: flex;
  align-items: center;
  gap: 3px;
  font-family: var(--font-sans);
}
.map-zoom-ctrl button {
  width: 26px; height: 26px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  cursor: pointer;
  font-size: 0.9rem;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.1s;
}
.map-zoom-ctrl button:hover { background: var(--bg-code); }
#map-zoom-label {
  min-width: 40px;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-sub);
  font-family: var(--font-sans);
}

/* 범례 바 */
.map-legend {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 5px 14px;
  font-size: 0.72rem;
  font-family: var(--font-sans);
  color: var(--text-sub);
  background: #f8f6ee;
  border: 1.5px solid var(--border);
  border-bottom: none;
  flex-wrap: wrap;
}
.legend-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  display: inline-block;
  vertical-align: middle;
  flex-shrink: 0;
}
.map-legend span:first-child {
  margin-right: 6px;
  color: var(--text-sub);
  border-right: 1px solid var(--border);
  padding-right: 10px;
}

/* ③ 경로 패널 */
.map-path-panel {
  position: fixed;
  bottom: 24px; right: 24px;
  background: #fff;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.18);
  z-index: 200;
  min-width: 180px;
  font-family: var(--font-sans);
  overflow: hidden;
}
.path-panel-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 12px;
  background: var(--bg-code);
  font-size: 0.82rem;
  font-weight: 600;
  gap: 8px;
}
.path-panel-head button {
  background: none; border: none;
  cursor: pointer; color: var(--text-sub);
  font-size: 0.9rem; padding: 0 2px;
  line-height: 1;
}
.path-panel-stats {
  display: flex;
  gap: 12px;
  padding: 8px 12px 4px;
  font-size: 0.78rem;
}
.pp-anc  { color: #1d4ed8; font-weight: 600; }
.pp-desc { color: #15803d; font-weight: 600; }
.path-panel-go {
  display: block;
  width: 100%;
  padding: 8px 12px;
  background: var(--accent);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 0.82rem;
  font-family: var(--font-sans);
  text-align: left;
  transition: background 0.1s;
}
.path-panel-go:hover { background: var(--accent-dark, #4a7c59); }

/* 맵 드래그 커서 */
.map-wrapper { cursor: grab; }
.map-wrapper:active { cursor: grabbing; }

/* ══════════════════════════════════════════════════════
   MAP AREA TABS
   ══════════════════════════════════════════════════════ */
.area-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 14px;
  flex-wrap: wrap;
  border: 1.5px solid var(--border);
  font-family: var(--font-sans);
}
.area-tabs button {
  padding: 5px 14px;
  border: none;
  border-right: 1px solid var(--border-mid);
  background: #f0ede4;
  cursor: pointer;
  font-size: 0.8rem;
  font-family: var(--font-sans);
}
.area-tabs button:last-child { border-right: none; }
.area-tabs button.active { background: var(--primary); color: #fff; }

/* ══════════════════════════════════════════════════════
   VISUAL / SVG
   ══════════════════════════════════════════════════════ */
.visual-container {
  display: flex; flex-wrap: wrap; gap: 12px; align-items: flex-start;
  overflow: hidden;
}
.visual-container svg, .visual-container table {
  max-width: 100%; height: auto;
  overflow: hidden;
  border: 1.5px solid var(--border);
  background: #fafaf7;
}
.vis-table {
  border-collapse: collapse;
  font-size: 0.84rem;
  margin: 6px 0;
  font-family: var(--font-sans);
  width: 100%;
}
.vis-table th, .vis-table td {
  padding: 6px 13px;
  border: 1px solid var(--border);
  text-align: center;
}
.vis-table th { background: #e8ecf5; font-weight: 700; }
.vis-table td { background: var(--surface); }

/* ══════════════════════════════════════════════════════
   특수값 공식 페이지 (FormulaView)
   ══════════════════════════════════════════════════════ */

.fv-page {
  max-width: 1100px;
}

.fv-page-header {
  border-bottom: 2px solid var(--border);
  padding-bottom: 14px;
  margin-bottom: 28px;
}

.fv-page-title {
  font-size: 1.45rem;
  font-weight: 800;
  font-family: var(--font-serif);
  letter-spacing: -0.5px;
}

.fv-page-desc {
  font-size: 0.85rem;
  color: var(--text-sub);
  font-family: var(--font-sans);
  margin-top: 5px;
}

/* ─── 삼각함수 특수값 표 ─── */
.fv-trig-section {
  margin-bottom: 32px;
  border: 2px solid var(--border);
}

.fv-trig-header {
  background: #2a2a3a;
  color: #fff;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  padding: 8px 16px;
}

.fv-trig-wrap {
  overflow-x: auto;
}

.fv-trig-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  font-family: var(--font-serif);
}

.fv-trig-table th {
  background: #edf0f8;
  border: 1px solid var(--border-mid);
  padding: 9px 14px;
  text-align: center;
  font-weight: 700;
}

.fv-trig-table td {
  background: var(--surface);
  border: 1px solid var(--border-thin);
  padding: 10px 12px;
  text-align: center;
  vertical-align: middle;
}

.fv-trig-table tr:nth-child(even) td {
  background: #fafaf7;
}

.fv-trig-table td:first-child {
  font-weight: 700;
  background: #f3f3ee;
  color: var(--primary);
  font-size: 0.82rem;
}

/* ─── 범주 섹션 ─── */
.fv-cat {
  margin-bottom: 28px;
  border: 1px solid var(--border-mid);
}

.fv-cat-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  color: #fff;
}

.fv-cat-badge {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  background: rgba(255,255,255,0.18);
  border: 1px solid rgba(255,255,255,0.35);
  padding: 2px 10px;
  border-radius: 3px;
  white-space: nowrap;
  letter-spacing: 0.5px;
}

.fv-cat-title {
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  opacity: 0.92;
}

/* ─── 공식 카드 그리드 ─── */
.fv-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 0;
  background: var(--border-thin);
}

.fv-card {
  background: var(--surface);
  padding: 18px 16px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  border: 0.5px solid var(--border-thin);
  transition: background 0.15s;
}

.fv-card:hover {
  background: #fdfcf6;
}

.fv-expr {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  font-size: 1rem;
  text-align: center;
}

.fv-note {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: var(--text-sub);
  text-align: center;
  line-height: 1.5;
  padding-top: 4px;
  border-top: 1px solid var(--border-thin);
  width: 100%;
}

/* ══════════════════════════════════════════════════════
   RESPONSIVE
   ══════════════════════════════════════════════════════ */
@media (max-width: 768px) {
  .sidebar { display: none; }
  .content { padding: 16px 18px; }
  #footer { left: 0; }
  .header-top { flex-direction: column; align-items: stretch; }
  .search-box { max-width: none; }
  .home-cover-title { font-size: 1.6rem; }
  .home-stats { gap: 18px; }
  .fv-grid { grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); }
}

/* ══════════════════════════════════════════════════════
   실력 체크 뷰 (check-view)
   ══════════════════════════════════════════════════════ */

/* ── 공통 ── */
.ck-page, .ck-result { max-width: 860px; padding-bottom: 40px; }
.ck-back {
  background: none; border: 1px solid var(--border);
  border-radius: 4px; padding: 5px 12px;
  cursor: pointer; font-family: var(--font-sans);
  font-size: 0.82rem; color: var(--text-sub);
  transition: background 0.1s;
}
.ck-back:hover { background: var(--bg-code); }

/* ── 학년 선택 ── */
.ck-hero { margin-bottom: 24px; }
.ck-hero-title {
  font-size: 1.5rem; font-weight: 800;
  font-family: var(--font-serif);
  margin-bottom: 6px;
}
.ck-hero-desc {
  font-size: 0.88rem; color: var(--text-sub);
  font-family: var(--font-sans); line-height: 1.6;
}
.ck-level-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 12px;
}
.ck-lv-btn {
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 16px 12px;
  text-align: center;
  cursor: pointer;
  background: #fff;
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.1s;
  font-family: var(--font-sans);
}
.ck-lv-btn:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  transform: translateY(-2px);
}
.ck-lv-name {
  font-size: 1.1rem; font-weight: 700; margin-bottom: 4px;
}
.ck-lv-range {
  font-size: 0.72rem; color: var(--text-sub); margin-bottom: 6px;
}
.ck-lv-count {
  font-size: 0.8rem; color: var(--accent); font-weight: 600;
}

/* ── 문제 수 설정 화면 ── */
.ck-settings-box {
  margin-top: 20px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  background: #fff;
  font-family: var(--font-sans);
}
.ck-settings-title {
  font-size: 1.05rem; font-weight: 700; margin-bottom: 16px;
}
.ck-settings-lv {
  font-size: 1.2rem; font-weight: 800;
  font-family: var(--font-serif); margin-right: 8px;
}
.ck-settings-range { font-size: 0.82rem; color: var(--text-sub); }
.ck-settings-label {
  font-size: 0.9rem; font-weight: 600; margin-bottom: 4px;
}
.ck-settings-desc {
  font-size: 0.78rem; color: var(--text-sub); margin-bottom: 14px;
}
.ck-preset-row {
  display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px;
}
.ck-preset-btn {
  padding: 7px 18px;
  border: 1.5px solid var(--border);
  border-radius: 20px;
  background: #fff; cursor: pointer;
  font-family: var(--font-sans); font-size: 0.85rem;
  transition: border-color 0.1s, background 0.1s, color 0.1s;
}
.ck-preset-btn:hover { border-color: var(--accent); background: var(--primary-light); }
.ck-preset-btn.active {
  border-color: var(--accent); background: var(--accent); color: #fff; font-weight: 600;
}
.ck-custom-row {
  display: flex; align-items: center; gap: 8px; margin-bottom: 20px;
}
.ck-custom-label { font-size: 0.82rem; color: var(--text-sub); white-space: nowrap; }
.ck-custom-input {
  width: 80px; padding: 6px 10px;
  border: 1.5px solid var(--border); border-radius: 4px;
  font-family: var(--font-sans); font-size: 0.85rem;
  text-align: center;
}
.ck-custom-input:focus { outline: none; border-color: var(--accent); }
.ck-start-btn {
  display: block; width: 100%;
  padding: 12px;
  background: var(--accent); color: #fff;
  border: none; border-radius: 6px;
  cursor: pointer; font-family: var(--font-sans);
  font-size: 1rem; font-weight: 700;
  transition: opacity 0.15s;
}
.ck-start-btn:hover { opacity: 0.88; }

/* ── 문제 화면 ── */
.ck-quiz-bar {
  position: sticky; top: var(--header-h); z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px; padding: 8px 0 10px;
  background: var(--bg);
  border-bottom: 1.5px solid var(--border);
  margin-bottom: 16px;
  font-family: var(--font-sans);
}
.ck-prog { font-size: 0.85rem; color: var(--text-sub); }
.ck-submit {
  padding: 7px 18px;
  background: var(--accent); color: #fff;
  border: none; border-radius: 5px;
  cursor: pointer; font-family: var(--font-sans);
  font-size: 0.85rem; font-weight: 600;
  transition: opacity 0.15s;
}
.ck-submit:disabled { opacity: 0.35; cursor: not-allowed; }
.ck-submit:not(:disabled):hover { opacity: 0.85; }

.ck-list { display: flex; flex-direction: column; gap: 16px; }
.ck-card {
  border: 1.5px solid var(--border);
  border-radius: 6px; padding: 14px 16px;
  background: #fff;
  font-family: var(--font-sans);
}
.ck-qmeta {
  font-size: 0.75rem; color: var(--text-sub);
  margin-bottom: 6px; font-weight: 600;
}
.ck-qlv { font-weight: 400; }
.ck-qtext {
  font-size: 0.9rem; margin-bottom: 10px; line-height: 1.55;
}
.ck-choices { display: flex; flex-direction: column; gap: 6px; }
.ck-ch {
  text-align: left;
  padding: 7px 12px;
  border: 1.5px solid var(--border-thin);
  border-radius: 4px;
  background: #fff; cursor: pointer;
  font-family: var(--font-sans); font-size: 0.85rem;
  transition: border-color 0.1s, background 0.1s;
}
.ck-ch:hover { border-color: var(--accent); background: var(--primary-light); }
.ck-ch.sel {
  border-color: var(--accent); background: var(--primary-light);
  font-weight: 600;
}

/* ── 결과 화면 ── */
.ck-res-header {
  display: flex; align-items: center; gap: 16px;
  margin-bottom: 20px;
}
.ck-res-title {
  font-size: 1.1rem; font-weight: 700;
  font-family: var(--font-serif);
}

.ck-score-box {
  border: 1.5px solid var(--border);
  border-radius: 8px; padding: 24px;
  text-align: center;
  background: #fff; margin-bottom: 24px;
  font-family: var(--font-sans);
}
.ck-score-num {
  font-size: 3.5rem; font-weight: 800;
  font-family: var(--font-serif); line-height: 1;
  margin-bottom: 4px;
}
.ck-score-pt { font-size: 1.4rem; }
.ck-score-frac { font-size: 0.9rem; color: var(--text-sub); margin-bottom: 10px; }

.ck-grade-badge {
  display: inline-block; padding: 4px 16px;
  border-radius: 20px; font-size: 0.85rem; font-weight: 700;
  margin-bottom: 16px;
}
.ck-gr-great { background: #dcfce7; color: #15803d; }
.ck-gr-good  { background: #fef9c3; color: #854d0e; }
.ck-gr-fair  { background: #fee2e2; color: #b91c1c; }

.ck-gauge-wrap { max-width: 400px; margin: 0 auto; }
.ck-gauge-track {
  position: relative; height: 16px;
  background: #e2e8f0; border-radius: 8px;
  overflow: visible; margin-bottom: 4px;
}
.ck-gauge-fill {
  height: 100%; border-radius: 8px;
  background: linear-gradient(90deg, #818cf8, #6366f1);
  transition: width 0.6s ease;
}
.ck-gauge-mark {
  position: absolute; top: -4px;
  width: 2px; height: 24px;
  transform: translateX(-50%);
}
.ck-gauge-mark::before {
  content: ''; display: block;
  width: 2px; height: 100%;
}
.ck-gauge-mark:nth-child(3)::before { background: #f59e0b; }
.ck-gauge-mark:nth-child(4)::before { background: #22c55e; }
.ck-mark-label {
  position: absolute; top: 26px;
  font-size: 0.7rem; font-weight: 700;
  transform: translateX(-50%);
  font-family: var(--font-sans);
}
.ck-gauge-ends {
  display: flex; justify-content: space-between;
  font-size: 0.72rem; color: var(--text-sub);
  margin-top: 24px;
}

.ck-section { margin-bottom: 28px; }
.ck-section-title {
  font-size: 1rem; font-weight: 700;
  font-family: var(--font-serif);
  border-bottom: 2px solid var(--border);
  padding-bottom: 6px; margin-bottom: 14px;
}

/* 레이더 차트 */
.ck-radar-wrap { display: flex; justify-content: center; }
.ck-radar-legend {
  display: flex; gap: 16px; justify-content: center;
  font-size: 0.78rem; font-family: var(--font-sans);
  color: var(--text-sub); margin-top: 8px;
}

/* 바 차트 (fallback) */
.ck-bar-chart { display: flex; flex-direction: column; gap: 10px; }
.ck-bar-row {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-sans); font-size: 0.82rem;
}
.ck-bar-label { min-width: 120px; color: var(--text); }
.ck-bar-track {
  flex: 1; height: 14px; background: #e2e8f0; border-radius: 7px;
  position: relative;
}
.ck-bar-fill { height: 100%; border-radius: 7px; transition: width 0.5s; }
.ck-bar-mark {
  position: absolute; top: 0; width: 2px; height: 100%;
  background: rgba(0,0,0,0.25);
}
.ck-bar-pct { min-width: 36px; font-weight: 700; text-align: right; }

/* 틀린 문제 */
.ck-all-ok {
  text-align: center; padding: 24px;
  font-size: 1.1rem; color: var(--text-sub);
  font-family: var(--font-sans);
}
.ck-wrong-card {
  border: 1.5px solid var(--border);
  border-radius: 6px; padding: 14px 16px;
  margin-bottom: 12px; background: #fff;
  font-family: var(--font-sans);
}
.ck-ch-result {
  padding: 6px 12px; margin-bottom: 4px;
  border-radius: 4px; font-size: 0.85rem;
  border: 1.5px solid var(--border-thin);
}
.ck-ch-result.correct {
  border-color: #22c55e; background: #dcfce7; color: #15803d; font-weight: 600;
}
.ck-ch-result.wrong {
  border-color: #ef4444; background: #fee2e2; color: #b91c1c; font-weight: 600;
}

/* ── 결과 헤더 인쇄 버튼 ── */
.ck-res-header { justify-content: flex-start; flex-wrap: wrap; }
.ck-res-title  { flex: 1; }
.ck-print-btn  {
  padding: 5px 12px;
  border: 1.5px solid var(--border); border-radius: 4px;
  background: #fff; cursor: pointer;
  font-family: var(--font-sans); font-size: 0.78rem; color: var(--text-sub);
  transition: border-color 0.1s, background 0.1s;
}
.ck-print-btn:hover { border-color: var(--accent); background: var(--primary-light); }

/* ══════════════════════════════════════════════════════
   @media print
   ══════════════════════════════════════════════════════ */
@media print {
  #header, .sidebar, #footer,
  .ck-back, .ck-print-btn { display: none !important; }

  .container { margin-top: 0 !important; }
  .content {
    padding: 10px 20px !important;
    max-width: 100% !important;
    border: none !important;
    min-height: unset !important;
  }

  /* 배경색/그라디언트 강제 출력 */
  * { -webkit-print-color-adjust: exact !important; print-color-adjust: exact !important; }

  .ck-score-box, .ck-wrong-card { box-shadow: none !important; }
  .ck-wrong-card { break-inside: avoid; }
  .ck-score-box  { break-inside: avoid; }
}