@charset "UTF-8";

:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --sidebar: #f7f7f7;
  --ink: #252525;
  --muted: #717171;
  --line: #e9e9e9;
  --accent: #087f70;
  --accent-soft: #efefef;
  --code: #f6f6f6;
  --shadow: 0 18px 70px #14141420;
  --font-body: "Noto Sans", "Noto Sans KR", sans-serif;
  --font-code: "JetBrains Mono", "Nanum Gothic Coding", monospace;
  color-scheme: light;
  font-family: var(--font-body);
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font-size: 14px; }
button, input, textarea { font: inherit; }
button, a, input { touch-action: manipulation; }
button { cursor: pointer; color: inherit; background: none; border: 0; }
a { color: inherit; text-decoration: none; }
button:hover, a:hover { color: var(--accent); }
button:focus-visible, a:focus-visible, input:focus-visible, textarea:focus-visible, [tabindex]:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
button:disabled { opacity: .4; cursor: default; }
[hidden] { display: none !important; }
.skip-link { position: fixed; left: 12px; top: -100px; z-index: 20; padding: 12px; background: var(--surface); }
.skip-link:focus { top: 12px; }
.workspace { display: flex; height: 100dvh; min-height: 480px; }

.sidebar { width: var(--sidebar-width, 288px); flex-shrink: 0; background: var(--sidebar); display: flex; flex-direction: column; padding: 0 19px 24px; overflow: hidden; }
.sidebar-header { display: flex; align-items: center; min-height: 76px; padding: 0 11px; }
.brand { display: flex; flex-direction: column; align-items: flex-start; font-size: clamp(24px, 11cqw, 31.5px); font-weight: 730; letter-spacing: -.65px; line-height: 1.15; gap: 4px; }
.brand-suffix { font-size: 12px; font-weight: 600; letter-spacing: .18em; color: var(--muted); }
.brand, .brand:hover, .brand:focus-visible { color: var(--ink); }
.dark .brand, .dark .brand:hover, .dark .brand:focus-visible,
.dark .brand-suffix { color: #fff; }
.sidebar { container-type: inline-size; }
.sidebar-footer { flex-shrink: 0; margin-top: 16px; padding: 12px 5px 0; border-top: 1px solid var(--line); color: var(--muted); line-height: 1.6; }
.sidebar-footer small { font-size: 10px; }
.explorer-label { display: flex; min-height: 42px; align-items: center; justify-content: space-between; margin: 19px 8px 9px; color: var(--muted); font-size: 13px; }
.introduction-link { padding: 8px 0; font-size: 16px; font-weight: 700; color: var(--accent); text-align: left; }
.introduction-link.selected { color: var(--accent); font-weight: 700; }
.tree-search-wrap { display: flex; align-items: center; gap: 6px; padding: 0 5px 12px; flex-shrink: 0; }
#tree-search { min-width: 0; flex: 1; }
#toggle-folders { flex-shrink: 0; color: var(--muted); }
.panel-resizer { position: relative; width: 6px; flex: 0 0 6px; cursor: col-resize; touch-action: none; z-index: 2; }
.panel-resizer::before { content: ""; position: absolute; width: 1px; top: 0; bottom: 0; left: 2px; background: var(--line); transition: background .15s; }
.panel-resizer::after { content: ""; position: absolute; width: 10px; top: 0; bottom: 0; left: -2px; }
.panel-resizer:hover::before, .panel-resizer:focus-visible::before, .panel-resizer.dragging::before { background: var(--accent); width: 2px; }
.resizing-panels, .resizing-panels * { cursor: col-resize !important; user-select: none !important; }
#tree-search { width: 100%; padding: 10px 12px; border: 1px solid var(--line); border-radius: 5px; color: var(--ink); background: var(--bg); font-size: 13px; }
.tree { flex: 1; min-height: 0; overflow: auto; overscroll-behavior: contain; scrollbar-width: thin; scrollbar-color: var(--muted) transparent; padding-right: 5px; }
.sidebar-header, .explorer-label { flex-shrink: 0; }
.blog-section { display: flex; flex-direction: column; flex: 1; min-height: 130px; border-top: 1px solid var(--line); padding-top: 18px; }
.sidebar-section-title { font-size: 16px; font-weight: 700; color: var(--accent); margin: 0; line-height: 1.6; }
.sidebar-section-header { display: flex; align-items: center; justify-content: space-between; gap: 6px; padding: 0 5px 12px 8px; flex-shrink: 0; }
.section-toggle { flex-shrink: 0; color: var(--muted); }
.section-toggle[aria-expanded="false"] svg { transform: rotate(-90deg); }
.section-body { display: flex; flex-direction: column; flex: 1; min-height: 0; }
.blog-section.section-collapsed, .class-section.section-collapsed { flex: 0 0 auto; min-height: 0; max-height: none; }
.section-collapsed .sidebar-section-header { padding-bottom: 0; }
.class-section { border-top: 1px solid var(--line); padding-top: 18px; margin-top: 18px; display: flex; flex-direction: column; flex: 1; min-height: 100px; }
.class-tree { flex: 1; overflow: auto; min-height: 0; scrollbar-width: thin; overscroll-behavior: contain; }
.course-folder summary { cursor: pointer; display: flex; align-items: baseline; gap: 8px; padding: 9px 5px; font-size: 13px; line-height: 1.65; overflow-wrap: anywhere; list-style: none; }
.course-folder summary::-webkit-details-marker { display: none; }
.course-folder summary::marker { content: ''; }
.folder-toggle::before, .course-folder summary::before { content: ''; display: block; flex: 0 0 7px; width: 7px; height: 9px; background: var(--muted); clip-path: polygon(0 0, 100% 50%, 0 100%); }
.folder-toggle[aria-expanded="true"]::before, .course-folder[open] > summary::before { transform: rotate(90deg); }
.course-folder summary:hover { color: var(--accent); }
.course-folder summary:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }
.outline-hidden .outline, .outline-hidden #outline-resizer { display: none; }
.folder-title { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.library-feedback { font-size: 12px; line-height: 1.7; color: var(--muted); }
.library-feedback:has(#library-status:empty):has(#retry-library[hidden]) { display: none; }
#retry-library { padding: 5px; text-decoration: underline; }
.empty-state { font-size: 13px; color: var(--muted); padding: 8px; }
.icon-button { display: inline-grid; place-items: center; width: 30px; height: 30px; border-radius: 5px; font-size: 18px; }
.icon-button:hover { background: var(--accent-soft); }
.folder { margin: 0; }
.folder-toggle { display: flex; align-items: baseline; gap: 8px; width: 100%; padding: 9px 5px; text-align: left; font-size: 13px; font-weight: 400; line-height: 1.65; }
.folder-children { margin-left: 12px; border-left: 1px solid var(--line); padding-left: 6px; }
.tree-post { width: 100%; padding: 9px 8px; display: flex; gap: 7px; align-items: center; text-align: left; color: var(--muted); font-size: 13px; border-radius: 4px; line-height: 1.65; }
.tree-post:hover { color: var(--ink); background: var(--code); }
.tree-post.selected { color: var(--accent); background: var(--accent-soft); font-weight: 550; }
.tree-post .title { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.draft-dot { width: 5px; height: 5px; flex-shrink: 0; border-radius: 50%; background: var(--muted); margin-left: auto; }

.main { flex: 1; min-width: 0; display: flex; flex-direction: column; overflow: hidden; }
.topbar { height: 76px; flex-shrink: 0; display: flex; align-items: center; gap: 12px; border-bottom: 1px solid var(--line); padding: 0 36px; }
.topbar-actions { margin-left: auto; display: flex; align-items: center; gap: 10px; }
.topbar-actions .icon-button { width: 30px; height: 30px; padding: 6px; color: #c7c7c7; background: #414141; border: 1px solid #555; }
.topbar-actions .icon-button svg { width: 16px; height: 16px; }
.topbar-actions .icon-button:hover { background: #505050; color: #fff; }
.topbar-actions .icon-button[aria-pressed="true"] { background: #dedede; border-color: #c7c7c7; color: #292929; }
.topbar-actions .icon-button[aria-pressed="true"]:hover { background: #eee; color: #171717; }
.topbar-actions .icon-button > span:not(.sr-only) { display: inline-grid; place-items: center; }
#mode-toggle .mode-book, #mode-toggle[aria-pressed="true"] .mode-pen,
#theme-toggle .theme-sun, #theme-toggle[aria-pressed="false"] .theme-moon { display: none; }
#mode-toggle[aria-pressed="true"] .mode-book, #theme-toggle[aria-pressed="false"] .theme-sun { display: inline-grid; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.button { border: 1px solid var(--line); padding: 10px 17px; border-radius: 5px; font-size: 13px; font-weight: 550; background: var(--surface); }
.button:hover { border-color: var(--accent); }
.button-small { min-width: 64px; padding: 8px 15px; }
.button-primary { background: var(--ink); color: var(--surface); border-color: var(--ink); }
.button-primary:hover { color: var(--surface); opacity: .85; }
#sidebar-toggle, .mobile-close { display: none; }

.reading-layout { display: flex; flex: 1; min-height: 0; }
.pdf-layout { display: flex; flex: 1; min-height: 0; min-width: 0; overflow: hidden; }
#course-pdf { display: block; width: 100%; height: 100%; flex: 1; min-height: 0; border: 0; background: var(--surface); }
.article-scroll { flex: 1; min-width: 0; overflow: auto; scroll-behavior: smooth; }
.article { max-width: 912px; padding: 65px 64px 100px; margin: auto; }
.article h1 { font-size: clamp(29px, 2.7vw, 40px); letter-spacing: -1.5px; line-height: 1.4; margin: 0 0 46px; font-weight: 730; word-break: keep-all; }
.prose { font-size: 17px; line-height: 1.95; word-break: keep-all; overflow-wrap: anywhere; }
.prose h2 { font-size: 25px; letter-spacing: -.7px; line-height: 1.5; margin: 38px 0 18px; font-weight: 680; scroll-margin-top: 25px; }
.article .prose > div:first-child > h2 { margin-top: 0; }
.prose h3 { font-size: 20px; margin: 30px 0 15px; scroll-margin-top: 25px; }
.prose h4, .prose h5, .prose h6 { font-size: 18px; margin: 25px 0 12px; }
.prose p { margin: 0 0 23px; }
.prose hr { height: 0; border: 0; border-top: 1px solid var(--line); margin: 36px 0; }
.introduction-page h1 { margin-bottom: 20px; }
.introduction-page .prose > div:first-child > p { font-size: 24px; line-height: 1.6; margin-bottom: 50px; letter-spacing: -.6px; }
.prose strong { font-weight: 650; }
.prose a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.prose img { display: block; max-width: 100%; height: auto; margin: 24px auto; border-radius: 5px; }
.prose code { font-family: var(--font-code); font-size: .84em; background: var(--code); border-radius: 3px; padding: 2px 5px; }
.prose pre { position: relative; border: 1px solid var(--line); background: var(--code); padding: 37px 22px 22px; border-radius: 5px; overflow: auto; word-break: normal; line-height: 1.8; font-size: 14px; margin: 25px 0; }
.prose pre::before { content: attr(data-language); position: absolute; left: 22px; top: 10px; color: var(--muted); font-family: var(--font-code); font-size: 12px; }
.prose pre code { background: none; padding: 0; font-size: inherit; white-space: pre; }
.token.keyword { color: #ad3053; }
.token.string { color: #21724c; }
.token.number { color: #a15716; }
.token.function { color: #176a9c; }
.token.variable { color: #3b5065; }
.token.type { color: #087f70; }
.token.comment { color: #777777; font-style: italic; }
.code-monochrome .token { color: inherit !important; font-style: inherit; }
.prose blockquote { border-left: 2px solid var(--accent); margin: 26px 0; padding: 8px 20px; color: var(--muted); }
.prose .formula { text-align: center; padding: 24px 12px; overflow-x: auto; overflow-y: hidden; word-break: normal; }
.markdown-table { max-width: 100%; overflow-x: auto; margin: 25px 0; border: 1px solid var(--line); border-radius: 5px; -webkit-overflow-scrolling: touch; }
.markdown-table table { width: 100%; border-collapse: collapse; font-size: .88em; line-height: 1.7; text-align: left; }
.markdown-table th, .markdown-table td { padding: 11px 15px; min-width: 100px; vertical-align: top; border-bottom: 1px solid var(--line); border-right: 1px solid var(--line); }
.markdown-table th { background: var(--code); font-weight: 650; }
.markdown-table th:last-child, .markdown-table td:last-child { border-right: 0; }
.markdown-table tbody tr:last-child td { border-bottom: 0; }
.markdown-table .align-left { text-align: left; }
.markdown-table .align-center { text-align: center; }
.markdown-table .align-right { text-align: right; }
.outline { width: var(--outline-width, 216px); flex-shrink: 0; padding: 69px 25px; overflow: auto; }
.outline-title { font-size: 13px; font-weight: 550; margin: 0 0 21px; color: var(--ink); }
.outline nav { display: flex; flex-direction: column; gap: 17px; border-left: 1px solid var(--line); padding-left: 16px; }
.outline nav button { text-align: left; padding: 0; font-size: 13px; color: var(--muted); line-height: 1.7; }
.outline nav button:hover { color: var(--accent); }

.editor-layout { display: flex; flex-direction: column; flex: 1; min-height: 0; }
.editor-actions { display: flex; align-items: center; justify-content: space-between; gap: 12px; border-bottom: 1px solid var(--line); padding: 13px 24px; }
.format-toolbar { display: flex; gap: 5px; align-items: center; }
.format-toolbar button { font-size: 14px; padding: 5px 10px; border-radius: 4px; }
.format-toolbar button:hover { background: var(--accent-soft); }
#open-media { border-left: 1px solid var(--line); border-radius: 0; margin-left: 6px; font-size: 13px; }
.sync-label { font-size: 12px; color: var(--muted); display: flex; align-items: center; gap: 6px; white-space: nowrap; }
.sync-label input { accent-color: var(--accent); }
.editor-panes { display: grid; grid-template-columns: minmax(0, var(--editor-width, 50%)) 5px minmax(0, 1fr); flex: 1; min-height: 0; overflow: hidden; }
.source-pane, .preview-pane { display: flex; flex-direction: column; min-height: 0; overflow: hidden; }
.pane-label { padding: 15px 28px; color: var(--muted); font-size: 12px; flex-shrink: 0; }
.source-wrap { position: relative; flex: 1; min-height: 0; overflow: hidden; }
#source, .source-mirror { font-family: var(--font-code); font-size: 14px; line-height: 1.95; letter-spacing: 0; padding: 12px 28px 28px; white-space: pre-wrap; overflow-wrap: break-word; tab-size: 2; border: 0; margin: 0; box-sizing: border-box; }
#source { resize: none; width: 100%; height: 100%; display: block; background: transparent; color: var(--ink); outline-offset: -3px; }
#source, .editor-preview { overflow-anchor: none; scroll-behavior: auto; scrollbar-gutter: stable; }
.source-mirror { position: absolute; left: 0; top: 0; visibility: hidden; pointer-events: none; }
.pane-resizer { background: var(--line); cursor: col-resize; z-index: 1; touch-action: none; }
.pane-resizer:hover, .pane-resizer:focus { background: var(--accent); }
.editor-preview { flex: 1; overflow: auto; padding: 12px 28px 28px; font-size: 16px; }
.editor-preview h1 { font-size: 30px; line-height: 1.5; letter-spacing: -1px; margin: 0 0 30px; }
.editor-preview h2 { font-size: 23px; }
.editor-preview h3 { font-size: 19px; }
.editor-footer { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 15px 25px; border-top: 1px solid var(--line); }
.editor-footer > span { font-size: 12px; color: var(--muted); }
.editor-footer > div { display: flex; gap: 8px; margin-left: auto; }
.editor-tabs { display: none; }

dialog { border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--ink); padding: 28px; max-width: 680px; width: calc(100% - 32px); box-shadow: var(--shadow); }
dialog::backdrop { background: #16161666; backdrop-filter: blur(3px); }
.dialog-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 24px; }
.dialog-header h2 { font-size: 20px; letter-spacing: -.5px; margin: 0; }
.media-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.media-card { border: 1px solid var(--line); border-radius: 5px; overflow: hidden; padding: 0; text-align: left; }
.media-card:hover { border-color: var(--accent); }
.media-art { height: 90px; display: grid; place-items: center; background: var(--code); font-size: 28px; color: var(--muted); }
.media-card strong { display: block; font-size: 12px; font-weight: 550; padding: 12px 12px 5px; overflow-wrap: anywhere; }
.media-card small { display: block; padding: 0 12px 13px; font-size: 12px; color: var(--muted); }
.media-placeholder { margin: 24px 0; border: 1px solid var(--line); border-radius: 5px; overflow: hidden; }
.media-placeholder .media-art { height: 130px; font-size: 34px; }
.media-placeholder figcaption { padding: 12px 15px; font-size: 13px; color: var(--muted); }
.toast { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); background: var(--ink); color: var(--surface); padding: 13px 20px; border-radius: 5px; box-shadow: var(--shadow); z-index: 10; font-size: 13px; max-width: calc(100vw - 30px); width: max-content; line-height: 1.6; }

body.dark {
  --bg: #1a1a1a;
  --surface: #1a1a1a;
  --sidebar: #161616;
  --ink: #e4e4e4;
  --muted: #a1a1a1;
  --line: #2d2d2d;
  --accent: #75dfc6;
  --accent-soft: #292929;
  --code: #222222;
  color-scheme: dark;
}
.dark .token.keyword { color: #f3a0b5; }
.dark .token.string { color: #a2d5a6; }
.dark .token.number { color: #e9bb87; }
.dark .token.function { color: #8fceea; }
.dark .token.variable { color: #d3d3d3; }
.dark .token.type { color: #75dfc6; }
.dark .token.comment { color: #a1a1a1; }

@media (min-width: 1700px) {
  .article { padding-top: 80px; }
  .outline { padding-top: 84px; }
}
@media (max-width: 1200px) {
  .sidebar { padding-left: 13px; padding-right: 13px; }
  .article { padding-left: 40px; padding-right: 40px; }
  .outline { padding-left: 18px; padding-right: 18px; }
  .topbar { padding: 0 26px; }
}
@media (max-width: 1000px) {
  #outline-toggle { display: none; }
  .outline, #outline-resizer { display: none; }
  .article { max-width: 790px; }
  .format-toolbar button { padding: 5px 8px; }
  .editor-actions { padding: 12px 16px; }
}
@media (max-width: 760px) {
  .workspace { min-height: 0; }
  .sidebar { position: fixed; left: 0; top: 0; bottom: 0; z-index: 5; transform: translateX(-100%); width: 280px; transition: transform .2s; }
  #sidebar-resizer { display: none; }
  .sidebar.open { transform: translateX(0); }
  .sidebar-header { padding-left: 10px; }
  .scrim { position: fixed; inset: 0; background: #16161666; z-index: 4; }
  #sidebar-toggle, .mobile-close { display: inline-grid; }
  .mobile-close { margin-left: auto; }
  .topbar { height: 62px; padding: 0 18px; }
  .topbar-actions { gap: 12px; }
  .article { padding: 38px 25px 70px; }
  .article h1 { font-size: 31px; letter-spacing: -1.1px; margin-bottom: 36px; }
  .prose { font-size: 16px; }
  .prose h2 { font-size: 23px; }
  .editor-tabs { display: flex; gap: 2px; }
  .editor-tabs button { padding: 6px 7px; font-size: 12px; border-radius: 4px; color: var(--muted); }
  .editor-tabs button[aria-pressed="true"] { background: var(--accent-soft); color: var(--accent); }
  .format-toolbar { gap: 0; }
  .format-toolbar button { padding: 5px; font-size: 13px; }
  #open-media span { display: none; }
  #open-media { margin-left: 2px; }
  .sync-label { font-size: 11px; gap: 2px; }
  .editor-actions { gap: 4px; padding: 10px 12px; flex-wrap: wrap; }
  .editor-panes { display: block; }
  .source-pane, .preview-pane { height: 100%; }
  .pane-resizer, .preview-pane, .pane-label { display: none; }
  .editor-panes.mobile-preview .source-pane { display: none; }
  .editor-panes.mobile-preview .preview-pane { display: flex; }
  .editor-preview, #source, .source-mirror { padding: 24px; }
  .editor-footer { padding: 12px 15px; }
  .button { padding: 9px 12px; }
  .media-grid { grid-template-columns: repeat(2, 1fr); }
  dialog { padding: 20px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}

.prose .formula .katex-display { margin: 0; }
.prose .math-error, .prose .katex-error { color: var(--muted); overflow-wrap: anywhere; }