@font-face {
  font-family: 'Pretendard Variable';
  src: url('/fonts/PretendardVariable.woff2') format('woff2');
  font-style: normal;
  font-weight: 45 920;
  font-display: swap;
}

:root {
  --ink: #111111;
  --paper: #f7fbff;
  --plain: #ffffff;
  --yellow: #dbeafe;
  --pink: #bfdbfe;
  --blue: #5294ff;
  --green: #e8f2ff;
  --violet: #9fc5ff;
  --orange: #5294ff;
  --shadow: 7px 7px 0 var(--ink);
  --shadow-small: 4px 4px 0 var(--ink);
  --border: 3px solid var(--ink);
  --radius: 6px;
  --sidebar-width: 288px;
  --content-max: 1520px;
  --toc-width: 420px;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(37, 99, 170, 0.12) 1px, transparent 1px),
    linear-gradient(rgba(37, 99, 170, 0.12) 1px, transparent 1px), #dbeafe;
  background-size: 42px 42px;
  font-family: 'Pretendard Variable', Pretendard, sans-serif;
  line-height: 1.65;
}

a {
  color: inherit;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 10px;
  left: 10px;
  padding: 10px 14px;
  color: var(--plain);
  text-decoration: none;
  background: var(--ink);
  border: 2px solid var(--plain);
  border-radius: var(--radius);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

button,
input {
  font: inherit;
}

.page-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  min-height: 100vh;
}

.page-shell.is-home .tools {
  display: none;
}

.sidebar-toggle,
.toc-toggle {
  display: none;
}

.page-shell.is-home .topbar {
  width: min(100%, 980px);
  margin-right: auto;
  margin-left: auto;
}

.sidebar {
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  height: 100vh;
  padding: 20px;
  overflow-y: auto;
  color: var(--ink);
  background: #5294ff;
  border-right: var(--border);
}

.brand {
  display: grid;
  grid-template-columns: 87px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  margin-bottom: 22px;
  text-decoration: none;
}

.brand-mark {
  width: 87px;
  height: 87px;
  display: block;
  object-fit: contain;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
}

.brand strong {
  display: block;
  font-size: 23px;
  font-weight: 950;
  line-height: 1.2;
}

.brand strong span {
  display: block;
  white-space: nowrap;
}

.doc-nav {
  display: grid;
  gap: 11px;
}

.doc-link {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 10px;
  align-items: center;
  width: 100%;
  padding: 11px;
  color: var(--ink);
  text-align: left;
  text-decoration: none;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
  cursor: pointer;
  transition:
    transform 140ms ease,
    box-shadow 140ms ease,
    background 140ms ease;
}

.doc-link:hover,
.doc-link:focus-visible {
  transform: translate(3px, 3px);
  box-shadow: 1px 1px 0 var(--ink);
  outline: none;
}

.doc-link:active {
  transform: translate(4px, 4px);
  box-shadow: 0 0 0 var(--ink);
}

.doc-link.is-active {
  background: var(--blue);
}

.doc-link:nth-child(3n).is-active {
  background: var(--blue);
}

.doc-link:nth-child(3n + 1).is-active {
  background: var(--blue);
}

.doc-index {
  display: grid;
  place-items: center;
  min-width: 34px;
  height: 34px;
  color: var(--plain);
  background: var(--ink);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 950;
}

.doc-link strong,
.doc-link small {
  display: block;
}

.doc-link strong {
  line-height: 1.2;
}

.doc-link small {
  margin-top: 3px;
  font-size: 12px;
  font-weight: 760;
}

.workspace {
  min-width: 0;
  padding: 42px 48px 72px;
}

.topbar {
  display: flex;
  width: min(100%, var(--content-max));
  gap: 18px;
  align-items: center;
  justify-content: space-between;
  margin: 0 auto 22px;
  padding: 18px;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

h1 {
  margin: 0;
  font-size: clamp(28px, 4vw, 56px);
  line-height: 0.98;
  letter-spacing: 0;
}

.tools {
  display: grid;
  grid-area: tools;
  gap: 12px;
}

.search-box {
  display: grid;
  gap: 8px;
  width: 100%;
  padding: 12px;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
  font-size: 12px;
  font-weight: 950;
  text-transform: uppercase;
}

.search-box input[type='search'] {
  width: 100%;
  padding: 12px 13px;
  background: var(--paper);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
}

.search-box input:focus {
  outline: 3px solid var(--blue);
}

.search-status {
  min-height: 1.4em;
  font-size: 13px;
  font-weight: 800;
  text-transform: none;
}

.content-layout {
  display: grid;
  width: min(100%, var(--content-max));
  position: relative;
  grid-template-columns: minmax(0, 1fr) var(--toc-width);
  grid-template-areas:
    'tools tools'
    'reader toc';
  gap: 18px;
  align-items: start;
  margin: 0 auto;
}

.resize-handle {
  position: absolute;
  z-index: 20;
  top: 0;
  bottom: 0;
  width: 34px;
  padding: 0;
  appearance: none;
  background: transparent;
  border: 0;
  cursor: col-resize;
}

.resize-handle::after {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 8px;
  height: 68px;
  content: '';
  background: transparent;
  border-radius: 999px;
  transform: translate(-50%, -50%);
}

.resize-handle:focus-visible {
  outline: none;
}

.resize-handle:focus-visible::after {
  background: var(--blue);
  border: 2px solid var(--ink);
  box-shadow: var(--shadow-small);
}

body.is-resizing {
  cursor: col-resize;
  user-select: none;
}

.resize-handle-toc {
  right: calc(var(--toc-width) - 8px);
}

.page-shell.is-home .resize-handle {
  display: none;
}

.reader {
  grid-area: reader;
  min-width: 0;
}

.home-page.is-active .home-reader {
  grid-column: 1 / -1;
}

.home-reader {
  width: min(100%, 980px);
  min-width: 0;
  justify-self: center;
  padding: 18px;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.home-intro {
  max-width: 780px;
  margin: 0 0 18px;
  font-size: 18px;
  font-weight: 850;
  line-height: 1.55;
}

.home-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.home-card {
  display: grid;
  gap: 9px;
  min-height: 96px;
  padding: 15px;
  color: var(--ink);
  text-decoration: none;
  background: var(--paper);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
  transition:
    transform 140ms ease,
    box-shadow 140ms ease,
    background 140ms ease;
}

.home-card:hover,
.home-card:focus-visible {
  background: var(--blue);
  outline: none;
  transform: translate(3px, 3px);
  box-shadow: 1px 1px 0 var(--ink);
}

.home-card:active {
  transform: translate(4px, 4px);
  box-shadow: 0 0 0 var(--ink);
}

.home-card strong {
  font-size: 20px;
  line-height: 1.2;
}

.home-card span {
  width: fit-content;
  padding: 4px 8px;
  background: var(--yellow);
  border: 2px solid var(--ink);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 950;
}

.doc-heading {
  margin: 0 0 16px;
  padding: 18px;
  background: var(--ink);
  color: var(--plain);
  border: var(--border);
  border-color: var(--ink);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-size: clamp(30px, 5vw, 66px);
  line-height: 0.96;
  letter-spacing: 0;
}

.reader > p {
  margin: 0 0 18px;
  padding: 14px 16px;
  background: var(--yellow);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
  font-weight: 750;
}

.question-card {
  margin: 0 0 22px;
  padding: 0;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.question-card.is-hidden {
  display: none;
}

.question-top {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 16px;
  align-items: start;
  padding: 16px;
  background: var(--blue);
  border-bottom: var(--border);
}

.question-title {
  margin: 0;
  font-size: clamp(20px, 3vw, 30px);
  line-height: 1.2;
  letter-spacing: 0;
}

.question-title:focus-visible {
  outline: 3px solid var(--ink);
  outline-offset: 4px;
}

.section-title {
  display: inline-block;
  margin: 22px 16px 8px;
  padding: 4px 10px;
  background: var(--ink);
  color: var(--plain);
  border-radius: 999px;
  font-size: 14px;
  font-weight: 950;
}

.followup-title {
  background: var(--blue);
  color: var(--ink);
  border: 2px solid var(--ink);
  box-shadow: var(--shadow-small);
}

.question-card p,
.question-card ul,
.question-card ol,
.question-card pre,
.question-card table {
  margin-right: 16px;
  margin-left: 16px;
}

.question-card p {
  margin-top: 8px;
  margin-bottom: 12px;
}

.question-card ul,
.question-card ol {
  padding-left: 24px;
}

.question-card li {
  margin: 8px 0;
}

.question-card .followup-list {
  display: grid;
  gap: 14px;
  margin: 8px 16px 22px;
}

.question-card .followup-item {
  overflow: hidden;
  background: var(--plain);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
}

.question-card .followup-question,
.question-card .followup-answer {
  margin: 0;
  padding: 12px;
}

.question-card .followup-question {
  background: var(--plain);
  border-bottom: 2px solid var(--ink);
  font-weight: 850;
}

.question-card .followup-answer {
  background: var(--paper);
}

.question-card .followup-answer + .followup-answer {
  border-top: 2px solid var(--ink);
}

.followup-label,
.answer-label {
  display: inline-block;
  margin-right: 8px;
  padding: 2px 7px;
  background: var(--blue);
  border: 2px solid var(--ink);
  border-radius: 999px;
  font-size: 12px;
  font-weight: 950;
  line-height: 1.2;
}

.answer-label {
  background: var(--yellow);
}

.question-card code {
  padding: 2px 6px;
  background: var(--yellow);
  border: 1px solid var(--ink);
  border-radius: 4px;
  font-weight: 800;
}

.question-card pre {
  padding: 14px;
  overflow-x: auto;
  background: var(--ink);
  color: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
}

.reader pre {
  max-width: 100%;
  padding: 14px;
  overflow-x: auto;
  background: var(--ink);
  color: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
}

.reader pre code {
  display: block;
  padding: 0;
  background: transparent;
  border: 0;
  color: inherit;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.code-tabs {
  margin: 8px 16px 22px;
  overflow: hidden;
  background: var(--paper);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
}

.code-tab-list {
  display: flex;
  gap: 0;
  overflow-x: auto;
  background: #e5e7eb;
  border-bottom: 2px solid var(--ink);
}

.code-tab {
  min-width: 72px;
  padding: 10px 14px;
  color: var(--ink);
  background: transparent;
  border: 0;
  border-right: 2px solid var(--ink);
  font-weight: 850;
  cursor: pointer;
}

.code-tab.is-active,
.code-tab:hover {
  background: var(--blue);
}

.code-tab:focus-visible {
  position: relative;
  z-index: 1;
  background: var(--blue);
  outline: none;
  box-shadow: inset 0 0 0 3px var(--ink);
}

.code-panel {
  display: none;
}

.code-panel.is-active {
  display: block;
}

.code-filebar {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  padding: 8px 12px;
  color: #4b5563;
  background: #f3f4f6;
  border-bottom: 1px solid #d1d5db;
  font-size: 13px;
  font-weight: 850;
}

.code-file-icon {
  display: grid;
  place-items: center;
  width: 26px;
  height: 22px;
  color: var(--plain);
  background: #6b7280;
  border: 2px solid var(--ink);
  border-radius: 5px;
  box-shadow: 2px 2px 0 var(--ink);
  font-size: 10px;
  font-weight: 950;
  line-height: 1;
}

.code-file-icon-cpp {
  color: var(--ink);
  background: #60a5fa;
}

.code-file-icon-java {
  color: var(--ink);
  background: #f87171;
}

.code-file-icon-python {
  color: var(--ink);
  background: #facc15;
}

.code-tabs pre {
  max-height: 520px;
  margin: 0;
  padding: 16px;
  overflow: auto;
  color: var(--ink);
  background: #f8fafc;
  border: 0;
  border-radius: 0;
  font-family: 'Consolas', monospace;
  font-size: 13px;
  line-height: 1.45;
}

.code-tabs pre:focus-visible {
  outline: 3px solid var(--ink);
  outline-offset: -3px;
}

.code-tabs code {
  display: block;
  padding: 0;
  color: inherit;
  background: transparent;
  border: 0;
  font-family: 'Consolas', monospace;
  white-space: pre;
}

.code-token-keyword {
  color: #7c3aed;
  font-weight: 850;
}

.code-token-type {
  color: #0369a1;
  font-weight: 850;
}

.code-token-function {
  color: #2563eb;
  font-weight: 850;
}

.code-token-string {
  color: #b45309;
}

.code-token-number {
  color: #dc2626;
}

.code-token-comment {
  color: #6b7280;
  font-style: italic;
}

.code-token-preprocessor {
  color: #be185d;
  font-weight: 850;
}

.reader table {
  width: calc(100% - 32px);
  border-collapse: collapse;
  background: var(--plain);
  border: var(--border);
}

.reader th,
.reader td {
  padding: 10px;
  border: 2px solid var(--ink);
  vertical-align: top;
}

.reader th {
  background: var(--yellow);
}

.toc-panel {
  grid-area: toc;
  position: sticky;
  top: 20px;
  max-height: calc(100vh - 40px);
  padding: 14px;
  overflow-y: auto;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
}

.toc-panel h2 {
  margin: 0 0 10px;
  font-size: 20px;
}

.toc {
  display: grid;
  gap: 8px;
}

.toc-link {
  display: block;
  padding: 8px 10px;
  color: var(--ink);
  text-decoration: none;
  background: var(--paper);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 850;
}

.toc-link:hover,
.toc-link:focus-visible {
  background: var(--violet);
  outline: none;
}

.toc-link.is-hidden {
  display: none;
}

.empty-state,
.loading-state {
  padding: 22px;
  background: var(--yellow);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-weight: 900;
}

.empty-state {
  margin: 0 0 22px;
}

.document-error {
  grid-column: 1 / -1;
}

@media (max-width: 1100px) {
  .page-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: sticky;
    z-index: 50;
    top: 0;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 12px;
    height: auto;
    max-height: 100vh;
    padding: 14px;
    overflow-y: auto;
    border-right: 0;
    border-bottom: var(--border);
  }

  .brand {
    margin-bottom: 0;
  }

  .sidebar-toggle,
  .toc-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 9px 12px;
    color: var(--ink);
    background: var(--plain);
    border: 2px solid var(--ink);
    border-radius: var(--radius);
    box-shadow: var(--shadow-small);
    font-weight: 900;
    cursor: pointer;
  }

  .sidebar-toggle:focus-visible,
  .toc-toggle:focus-visible {
    outline: 3px solid var(--plain);
    outline-offset: 2px;
  }

  .doc-nav {
    display: none;
  }

  .sidebar[data-nav-open='true'] .doc-nav {
    display: grid;
    grid-column: 1 / -1;
  }

  .doc-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .content-layout {
    grid-template-columns: 1fr;
    grid-template-areas:
      'tools'
      'reader';
  }

  .content-layout.is-toc-open {
    grid-template-areas:
      'tools'
      'toc'
      'reader';
  }

  .resize-handle {
    display: none;
  }

  .tools,
  .reader,
  .toc-panel {
    grid-column: 1;
  }

  .doc-page.is-active .toc-panel {
    display: none;
  }

  .content-layout.is-toc-open .doc-page.is-active .toc-panel {
    display: block;
    position: static;
    max-height: min(60vh, 560px);
  }

  .toc {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .workspace,
  .question-card {
    scroll-margin-top: 100px;
  }
}

@media (max-width: 720px) {
  .workspace {
    padding: 18px;
  }

  .topbar {
    display: grid;
  }

  .tools {
    justify-content: stretch;
  }

  .search-box {
    width: 100%;
  }

  .doc-nav,
  .home-links,
  .toc {
    grid-template-columns: 1fr;
  }

  .question-top {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .sidebar {
    gap: 8px;
    padding: 10px;
  }

  .brand {
    grid-template-columns: 66px minmax(0, 1fr);
    gap: 8px;
  }

  .brand-mark {
    width: 66px;
    height: 66px;
  }

  .brand strong {
    font-size: clamp(16px, 4.8vw, 19px);
  }

  .sidebar-toggle {
    min-height: 44px;
    padding: 8px;
    font-size: clamp(13px, 3.6vw, 14px);
    white-space: nowrap;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

.reader-section-heading {
  display: inline-block;
  margin: 20px 0 12px;
  padding: 8px 12px;
  background: var(--yellow);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
  font-size: 24px;
  line-height: 1.2;
}

.doc-page {
  display: none;
}

.doc-page.is-active {
  display: contents;
}

.reader > ul,
.reader > ol {
  margin: 0 0 18px;
  padding: 16px 18px 16px 34px;
  background: var(--plain);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-small);
  font-weight: 750;
}

.reader > pre {
  margin: 0 0 18px;
}

.bio-home-link {
  display: block;
  color: var(--ink);
  padding: 0.75rem 0;
  font-size: 0.875rem;
  font-weight: 700;
}
@media (max-width: 1100px) {
  .bio-home-link {
    grid-column: 1 / -1;
  }
}