/**
 * 비트세이빙 배움터 (Learn)
 * - 레이아웃: 사이드·TOC 각 240px / 본문 968px — learn-layout 3열 그리드
 * - UI: 페이지 배경 회색, 좌·중·우 패널 분리 (계산기 styles-common 토큰)
 */

/* 푸터를 뷰포트 하단에 붙이는 페이지 골격 */
body.page-learn {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  --learn-common-header-stack: 180px;
}

body.page-learn > .header-container {
  flex-shrink: 0;
  width: 100%;
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
  box-sizing: border-box;
}

/* 흰 카드 바깥 너비 = 컨테이너 콘텐츠 트랙 968px (계산기 페이지와 동일) */
body.page-learn > .header-container .header-section {
  width: 100%;
  box-sizing: border-box;
}

body.page-learn > .learn-page {
  flex: 1 0 auto;
  width: 100%;
}

body.page-learn > #commonFooterMount {
  flex-shrink: 0;
  width: 100%;
  margin-top: auto;
}

body.page-learn #commonFooterMount .footer {
  margin-top: 0;
}

.learn-page {
  --learn-container-max: 968px;
  --learn-gutter: 16px;
  --learn-column-gap: 20px;
  --learn-side-panel-width: 240px;
  --learn-sidebar-width: var(--learn-side-panel-width);
  --learn-toc-width: var(--learn-side-panel-width);
  --learn-layout-max: calc(
    var(--learn-side-panel-width) + var(--learn-column-gap) +
      var(--learn-container-max) + var(--learn-column-gap) +
      var(--learn-side-panel-width)
  );
  /* TOC 숨김 시: 사이드+본문 합계 = 헤더·본문 열과 동일 968px */
  --learn-layout-2col-max: var(--learn-container-max);
  --learn-main-2col-width: calc(
    var(--learn-container-max) - var(--learn-sidebar-width) -
      var(--learn-column-gap)
  );
  /* 본문은 .learn-main 카드 너비를 꽉 사용 (별도 680px 제한 없음) */
  --learn-mobile-bar-height: 48px;
  /* TOC·# 클릭 시 제목이 헤더 아래 이만큼 내려옴 (값 키우면 더 위로) */
  --learn-scroll-margin: 1rem;
  --learn-sticky-top: var(--learn-common-header-stack);
  --learn-panel-radius: var(--radius-lg);
  --learn-panel-border: 1px solid var(--border-color);
  --learn-panel-shadow: var(--shadow-sm);

  box-sizing: border-box;
  background: var(--bg-primary);
  padding-bottom: 24px;
}

.learn-page *,
.learn-page *::before,
.learn-page *::after {
  box-sizing: border-box;
}

body:has(> .header-container + .learn-page) .learn-page {
  --learn-sticky-top: var(--learn-common-header-stack);
}

/* 모바일 네비 — 버튼에 섹션·글 제목 표시, 탭 시 목록 */
.learn-page .learn-mobile-bar {
  display: none;
  width: calc(100% - var(--learn-gutter) * 2);
  max-width: var(--learn-container-max);
  margin: 0 auto;
  padding: 0;
  box-sizing: border-box;
  background: var(--bg-primary);
}

.learn-page .learn-mobile-toggle {
  width: 100%;
  box-sizing: border-box;
  min-height: var(--learn-mobile-bar-height);
  padding: 10px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border: var(--learn-panel-border);
  border-radius: var(--learn-panel-radius);
  background: var(--bg-white);
  box-shadow: var(--learn-panel-shadow);
  cursor: pointer;
  text-align: left;
  font: inherit;
  color: inherit;
}

.learn-page .learn-mobile-toggle-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
  flex: 1;
}

.learn-page .learn-mobile-section {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.3;
}

.learn-page .learn-mobile-article {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  line-height: 1.35;
}

.learn-page .learn-mobile-chevron {
  flex-shrink: 0;
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--text-secondary);
  border-bottom: 2px solid var(--text-secondary);
  transform: rotate(45deg);
  margin-top: -4px;
  transition: transform var(--transition-fast);
}

.learn-page.learn-nav-open .learn-mobile-chevron {
  transform: rotate(225deg);
  margin-top: 2px;
}

.learn-page .learn-mobile-toggle:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
}

.learn-page.learn-nav-open .learn-mobile-toggle {
  border-color: var(--primary-color);
  color: var(--primary-color);
  background: rgba(102, 126, 234, 0.08);
}

.learn-page .learn-mobile-dropdown {
  display: none;
  width: calc(100% - var(--learn-gutter) * 2);
  max-width: var(--learn-container-max);
  margin: 0 auto;
  padding: 12px 14px 16px;
  box-sizing: border-box;
  background: var(--bg-white);
  border: var(--learn-panel-border);
  border-top: none;
  border-radius: 0 0 var(--learn-panel-radius) var(--learn-panel-radius);
  box-shadow: var(--learn-panel-shadow);
  max-height: min(60vh, 400px);
  overflow-y: auto;
  flex-direction: column;
  gap: 2px;
}

/*
 * 3열 그리드: 240px | 본문 968px | 240px
 * learn-page 자체는 그리드가 아님 — learn-layout만 그리드, 전체 블록을 margin auto로 중앙
 */
.learn-page .learn-layout {
  display: grid;
  width: 100%;
  max-width: var(--learn-layout-max);
  margin: 12px auto 0;
  padding: 0 0 24px;
  box-sizing: border-box;
  grid-template-columns:
    var(--learn-sidebar-width)
    minmax(0, var(--learn-container-max))
    var(--learn-toc-width);
  column-gap: var(--learn-column-gap);
  align-items: start;
}

.learn-page .learn-sidebar {
  grid-column: 1;
  width: var(--learn-sidebar-width);
  position: sticky;
  top: var(--learn-sticky-top);
  max-height: calc(100vh - var(--learn-sticky-top) - 32px);
  overflow-y: auto;
  padding: 16px 12px;
  background: var(--bg-white);
  border: var(--learn-panel-border);
  border-radius: var(--learn-panel-radius);
  box-shadow: var(--learn-panel-shadow);
  scrollbar-width: none;
}

.learn-page .learn-sidebar:hover,
.learn-page .learn-toc:hover {
  scrollbar-width: thin;
  scrollbar-color: rgba(0, 0, 0, 0.12) transparent;
}

.learn-page .learn-sidebar::-webkit-scrollbar,
.learn-page .learn-toc::-webkit-scrollbar {
  width: 0;
}

.learn-page .learn-sidebar:hover::-webkit-scrollbar,
.learn-page .learn-toc:hover::-webkit-scrollbar {
  width: 6px;
}

.learn-page .learn-sidebar::-webkit-scrollbar-thumb,
.learn-page .learn-toc::-webkit-scrollbar-thumb {
  background: transparent;
  border-radius: 3px;
}

.learn-page .learn-sidebar:hover::-webkit-scrollbar-thumb,
.learn-page .learn-toc:hover::-webkit-scrollbar-thumb {
  background: rgba(0, 0, 0, 0.12);
}

.learn-page .learn-sidebar::-webkit-scrollbar-track,
.learn-page .learn-toc::-webkit-scrollbar-track {
  background: transparent;
}

.learn-page .learn-toc {
  grid-column: 3;
  width: var(--learn-toc-width);
  position: sticky;
  top: var(--learn-sticky-top);
  max-height: calc(100vh - var(--learn-sticky-top) - 32px);
  overflow-y: auto;
  padding: 16px 12px;
  background: var(--bg-white);
  border: var(--learn-panel-border);
  border-radius: var(--learn-panel-radius);
  box-shadow: var(--learn-panel-shadow);
  font-size: 13px;
  scrollbar-width: none;
}

.learn-page .learn-sidebar .learn-sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

/* 중앙 본문 — 2번째 그리드 열, 바깥 너비 968px */
.learn-page .learn-main {
  grid-column: 2;
  min-width: 0;
  width: 100%;
  box-sizing: border-box;
  padding: 28px 32px;
  background: var(--bg-white);
  border: var(--learn-panel-border);
  border-radius: var(--learn-panel-radius);
}

.learn-page .learn-article {
  max-width: 100%;
  padding-bottom: 48px;
  margin-bottom: 48px;
  border-bottom: 1px solid var(--border-light);
}

.learn-page .learn-article:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.learn-page .learn-breadcrumb {
  margin: 0 0 20px;
  font-size: 13px;
  color: var(--text-muted);
}

.learn-page .learn-article h2,
.learn-page .learn-article h3,
.learn-page .learn-article h4 {
  scroll-margin-top: var(--learn-scroll-margin);
}

@media (max-width: 1023px) {
  .learn-page {
    --learn-scroll-margin: 5rem;
  }
}

.learn-page .learn-article h2 {
  margin-top: 0;
  margin-bottom: 16px;
  font-size: 2.0rem;
  font-weight: 700;
  color: var(--text-primary);
  border-bottom: none;
  padding-bottom: 0;
}

.learn-page .learn-article h3 {
  margin: 24px 0 12px;
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  border-bottom: none;
}

.learn-page .learn-article h4 {
  margin: 20px 0 10px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.learn-page .learn-article p {
  margin: 0 0 16px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.learn-page .learn-article strong {
  font-weight: 600;
  color: inherit;
}

.learn-page .learn-article em {
  font-style: italic;
}

.learn-page .learn-article p a {
  color: var(--link-color, #4d4dff);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.learn-page .learn-article p a:hover {
  color: var(--link-hover-color, #3333cc);
}

/* 외부·mailto 링크, 또는 md {icon} — 글자 뒤 SVG(새 창 아이콘) */
.learn-page .learn-article p a.learn-link-has-icon {
  display: inline;
  gap: 0.2em;
}

.learn-page .learn-article p a.learn-link-has-icon::after {
  content: '';
  display: inline-block;
  width: 0.85em;
  height: 0.85em;
  margin-left: 0.15em;
  vertical-align: -0.08em;
  background-color: currentColor;
  opacity: 0.85;
  -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none'%3E%3Cpath d='M5.5 3.5H12v6.5M12 3.5L4 11.5' stroke='black' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none'%3E%3Cpath d='M5.5 3.5H12v6.5M12 3.5L4 11.5' stroke='black' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  -webkit-mask-size: contain;
  mask-size: contain;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-position: center;
  mask-position: center;
}

.learn-page .learn-article .learn-figure {
  margin: 0 0 20px;
}

.learn-page .learn-article .learn-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm, 8px);
}

.learn-page .learn-article .learn-figure figcaption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* 이미지 바로 아래 @caption 출처·설명 */
.learn-page .learn-article .learn-image-caption {
  margin: 4px 0 20px;
  font-size: 12px;
  line-height: 1.45;
  color: var(--text-muted);
  text-align: center;
}

.learn-page .learn-article .learn-figure:has(+ .learn-image-caption) {
  margin-bottom: 8px;
}

/* 표 — md GitHub 스타일 + @table striped|compact|borderless|numeric */
.learn-page .learn-article .learn-table-wrap {
  width: 100%;
  max-width: 100%;
  margin: 0 0 20px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.learn-page .learn-article table.learn-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
  line-height: 1.5;
  color: var(--text-secondary);
  background: #fff;
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: var(--radius-sm, 8px);
  overflow: hidden;
}

.learn-page .learn-article table.learn-table th,
.learn-page .learn-article table.learn-table td {
  padding: 10px 14px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  text-align: center;
  vertical-align: middle;
}

.learn-page .learn-article table.learn-table thead th {
  background: #f9f9f9;
  color: var(--text-primary);
  font-weight: 600;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.learn-page .learn-article table.learn-table tbody tr:last-child td {
  border-bottom: none;
}

.learn-page .learn-article table.learn-table tbody tr:hover td {
  background: rgba(102, 126, 234, 0.04);
}

.learn-page .learn-article table.learn-table a {
  color: var(--link-color, #4d4dff);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.learn-page .learn-article table.learn-table a:hover {
  color: var(--link-hover-color, #3333cc);
}

.learn-page .learn-article table.learn-table--striped tbody tr:nth-child(even) td {
  background: #fafafa;
}

.learn-page .learn-article table.learn-table--striped tbody tr:nth-child(even):hover td {
  background: rgba(102, 126, 234, 0.06);
}

.learn-page .learn-article table.learn-table--compact th,
.learn-page .learn-article table.learn-table--compact td {
  padding: 6px 10px;
  font-size: 0.9rem;
}

.learn-page .learn-article table.learn-table--borderless {
  border: none;
}

.learn-page .learn-article table.learn-table--borderless th,
.learn-page .learn-article table.learn-table--borderless td {
  border-bottom-color: rgba(0, 0, 0, 0.04);
}

.learn-page .learn-article table.learn-table--numeric tbody td:not(:first-child) {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* @table rowheader — 1열이 행 제목일 때 (굵게·배경만, 정렬은 가운데 유지) */
.learn-page .learn-article table.learn-table--rowheader tbody td:first-child {
  font-weight: 600;
  color: var(--text-primary);
  text-align: center;
  background: #f7f8fa;
}

.learn-page .learn-article table.learn-table--rowheader tbody tr:hover td:first-child {
  background: #f0f2f6;
}

.learn-page .learn-article table.learn-table--rowheader tbody td:not(:first-child),
.learn-page .learn-article table.learn-table--rowheader thead th {
  text-align: center;
}

.learn-page .learn-article .learn-video {
  position: relative;
  width: 100%;
  margin: 0 0 20px;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  border-radius: var(--radius-sm, 8px);
  background: #111;
}

.learn-page .learn-article .learn-video iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.learn-page .learn-nav-group {
  margin-bottom: 20px;
}

.learn-page .learn-nav-group:last-child {
  margin-bottom: 0;
}

.learn-page .learn-nav-group-label {
  margin: 0 0 8px;
  padding: 0 4px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text-muted);
  text-transform: uppercase;
}

.learn-page .nav-item {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  text-decoration: none;
  font-size: 14px;
  line-height: 1.4;
  border-left: 3px solid transparent;
}

.learn-page .nav-item:hover {
  background: var(--bg-light);
  color: var(--primary-color);
}

.learn-page .nav-item.is-current {
  background: rgba(102, 126, 234, 0.1);
  color: var(--primary-color);
  font-weight: 600;
}

.learn-page .nav-item.is-locked {
  display: flex;
  align-items: flex-start;
  gap: 6px;
  cursor: not-allowed;
  pointer-events: none;
  opacity: 0.6;
}

.learn-page .nav-item.is-locked::before {
  content: '🔒';
  flex-shrink: 0;
  font-size: 0.85em;
  line-height: 1.4;
}

/* TOC — 글(1.) + 소제목(1-1.) 계층, TikTok Ads 문서 스타일 참고 */
.learn-page .learn-toc-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 16px;
  padding: 0 2px;
}

.learn-page .learn-toc-header-icon {
  position: relative;
  flex-shrink: 0;
  width: 14px;
  height: 10px;
  color: var(--text-muted);
}

.learn-page .learn-toc-header-icon::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 14px;
  height: 2px;
  border-radius: 1px;
  background: currentColor;
  box-shadow: 0 4px 0 currentColor, 0 8px 0 currentColor;
}

.learn-page .learn-toc-header-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  text-transform: uppercase;
}

.learn-page .learn-toc-nav {
  margin: 0;
}

.learn-page .learn-toc-list,
.learn-page .learn-toc-sublist {
  list-style: none;
  margin: 0;
  padding: 0;
}

.learn-page .learn-toc-entry {
  margin: 0 0 2;
}

.learn-page .learn-toc-link,
.learn-page .learn-toc-sublink {
  display: flex;
  align-items: flex-start;
  gap: 4px;
  padding: 3px 4px;
  text-decoration: none;
  line-height: 1.35;
  border-radius: 4px;
  transition: color 0.15s ease;
}

.learn-page .learn-toc-link {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.9rem;
}

.learn-page .learn-toc-sublink {
  color: var(--text-muted);
  font-weight: 400;
  font-size: 0.8125rem;
  padding: 4px 4px;
}

.learn-page .learn-toc-num {
  flex-shrink: 0;
  min-width: auto;
  font-variant-numeric: tabular-nums;
  color: inherit;
  opacity: 0.85;
}

.learn-page .learn-toc-sublink .learn-toc-num {
  min-width: auto;
}

.learn-page .learn-toc-text {
  flex: 1;
  min-width: 0;
}

.learn-page .learn-toc-link:hover,
.learn-page .learn-toc-sublink:hover {
  color: var(--primary-color);
}

.learn-page .learn-toc-link.is-active {
  color: var(--primary-color);
}

.learn-page .learn-toc-sublink.is-active {
  color: var(--primary-color);
  font-weight: 500;
}

.learn-page .learn-toc-sublist {
  margin: 0 0 6px 0.4em;
  padding-left: 12px;
  border-left: 1px solid rgba(0, 0, 0, 0.1);
}

.learn-page .learn-toc-entry.is-current .learn-toc-sublist {
  border-left-color: rgba(102, 126, 234, 0.35);
}

@media (min-width: 1024px) and (max-width: 1280px) {
  .learn-page .learn-main {
    padding: 24px 20px;
  }
}

/* 2열: 사이드+본문 합 968px (TOC 숨김, 헤더와 같은 너비) */
@media (min-width: 1024px) and (max-width: 1487px) {
  .learn-page .learn-layout {
    max-width: var(--learn-layout-2col-max);
    grid-template-columns:
      var(--learn-sidebar-width)
      minmax(0, var(--learn-main-2col-width));
  }

  .learn-page .learn-toc {
    display: none;
  }
}

/* 1023px 이하: 사이드·TOC 숨김 — 모바일 메뉴는 헤더·본문 사이, 스크롤 시 상단 고정 */
@media (max-width: 1023px) {
  .learn-page {
    --learn-sticky-top: var(--learn-mobile-bar-height);
  }

  .learn-page .learn-mobile-sticky {
    position: sticky;
    top: 0;
    z-index: 100;
    width: calc(100% - var(--learn-gutter) * 2);
    max-width: var(--learn-container-max);
    margin: 0 auto 12px;
    box-sizing: border-box;
  }

  .learn-page .learn-mobile-bar {
    display: block;
    position: relative;
    width: 100%;
    margin: 0;
  }

  .learn-page.learn-nav-open .learn-mobile-toggle {
    border-radius: var(--learn-panel-radius) var(--learn-panel-radius) 0 0;
  }

  .learn-page .learn-mobile-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    width: 100%;
    z-index: 99;
    margin: 0;
  }

  .learn-page.learn-nav-open .learn-mobile-dropdown {
    display: flex;
  }

  .learn-page .learn-layout {
    margin-top: 0;
    width: calc(100% - var(--learn-gutter) * 2);
    max-width: var(--learn-container-max);
    padding: 0 0 24px;
    grid-template-columns: minmax(0, 1fr);
  }

  .learn-page .learn-sidebar,
  .learn-page .learn-toc {
    display: none;
  }

  .learn-page .learn-main {
    grid-column: 1;
    padding: 20px 16px;
  }

}