:root {
  --bg-app: #f7f5f1;
  --bg-soft: #f1eee7;
  --border: #eae4d9;
  --border-light: #f0ece4;
  --border-input: #e5dfd4;

  --ink: #1c1a17;
  --ink-inverse: #f7f5f1;
  --muted: #6b6257;
  --faint: #a09889;

  --card-bg: #ffffff;
  --green-bg: #e8ebe3;
  --green-ink: #2b3226;
  --green-muted: #6e7864;
  --blue-bg: #e6eaf2;
  --blue-ink: #3a4763;

  --accent: #5b2a8c;
  --accent-strong: #4a2170;
  --accent-soft: #f1e9f9;

  --font-sans: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Gowun Batang', serif;
  --font-mono: 'IBM Plex Mono', monospace;

  --header-h: 56px;
  --pager-h: 56px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg-app);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  word-break: keep-all;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -48px;
  padding: 8px 14px;
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  z-index: 100;
}

.skip-link:focus {
  top: 8px;
}

/* ---------- header ---------- */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  padding: 0 28px;
  background: rgba(247, 245, 241, 0.96);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 1px;
  text-decoration: none;
}

.brand-title {
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.2;
  color: var(--accent);
}

.brand-sub {
  font-size: 11px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--muted);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.page-count {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--muted);
}

.toc-btn {
  display: none;
  padding: 6px 14px;
  border: 1px solid var(--border-input);
  border-radius: 10px;
  background: var(--card-bg);
  color: var(--ink);
  font: inherit;
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
}

.toc-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.js .toc-btn {
  display: inline-block;
}

/* ---------- 한 화면 한 페이지 레이아웃 (JS 사용 시) ---------- */
.js body {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

.js .site-header,
.js .pager {
  flex-shrink: 0;
}

.stage {
  min-width: 0;
}

.js .stage {
  position: relative;
  flex: 1;
  min-height: 0;
}

.js .page {
  display: none;
  position: absolute;
  inset: 0;
  overflow-y: auto;
  overflow-x: hidden;
}

.js .page.is-active {
  display: flex;
}

.page-inner {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 32px;
}

.js .page-inner {
  margin: auto;
}

@media (prefers-reduced-motion: no-preference) {
  .js .page.is-active {
    animation: page-in 0.22s ease-out;
  }

  @keyframes page-in {
    from {
      opacity: 0;
      transform: translateY(6px);
    }
    to {
      opacity: 1;
      transform: none;
    }
  }
}

/* ---------- 페이지 이동 막대 ---------- */
.pager {
  display: none;
  align-items: center;
  gap: 16px;
  height: var(--pager-h);
  padding: 0 28px;
  background: rgba(247, 245, 241, 0.96);
  border-top: 1px solid var(--border);
}

.js .pager {
  display: flex;
}

.pager-btn {
  min-width: 92px;
  padding: 9px 16px;
  border: 1px solid var(--border-input);
  border-radius: 12px;
  background: var(--card-bg);
  color: var(--ink);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.pager-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.pager-next {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.pager-next:hover:not(:disabled) {
  background: var(--accent-strong);
  color: #fff;
}

.pager-btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.progress {
  flex: 1;
  height: 5px;
  border-radius: 999px;
  background: var(--border);
  overflow: hidden;
}

.progress i {
  display: block;
  height: 100%;
  width: 0;
  border-radius: 999px;
  background: var(--accent);
  transition: width 0.25s ease;
}

/* ---------- 목차 ---------- */
.toc-overlay {
  position: fixed;
  inset: 0;
  z-index: 60;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(28, 26, 23, 0.4);
}

.toc-overlay[hidden] {
  display: none;
}

.toc-panel {
  width: 100%;
  max-width: 760px;
  max-height: 100%;
  overflow-y: auto;
  padding: 24px;
  border-radius: 20px;
  background: var(--bg-app);
}

.toc-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.toc-head h2 {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 24px;
  font-weight: 400;
}

.toc-close {
  padding: 6px 12px;
  border: 1px solid var(--border-input);
  border-radius: 10px;
  background: var(--card-bg);
  font: inherit;
  font-size: 13px;
  cursor: pointer;
}

.toc-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.toc-list a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border: 1px solid var(--border-light);
  border-radius: 12px;
  background: var(--card-bg);
  color: var(--ink);
  font-size: 14.5px;
  text-decoration: none;
}

.toc-list a:hover {
  border-color: var(--accent);
}

.toc-list a[aria-current='true'] {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
}

.toc-num {
  min-width: 22px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--faint);
}

.toc-foot {
  margin: 16px 0 0;
  text-align: center;
  font-size: 12.5px;
  color: var(--faint);
}

.toc-foot a {
  color: inherit;
}

/* ---------- 첫 페이지 ---------- */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: 40px;
  align-items: center;
}

.hero-tags {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.tag {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--muted);
}

.tag-accent {
  padding: 5px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}

.hero-title {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-size: 44px;
  font-weight: 400;
  line-height: 1.35;
  color: var(--ink);
}

.hero-title span {
  color: var(--accent);
}

.hero-lead {
  margin: 0 0 20px;
  font-size: 17px;
  color: var(--muted);
}

.hero-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip {
  padding: 8px 16px;
  border: 1px solid var(--border-input);
  border-radius: 12px;
  background: var(--card-bg);
  font-size: 14px;
  font-weight: 600;
}

/* ---------- 노트북 모양 ---------- */
.notebook {
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--card-bg);
  box-shadow: 0 1px 2px rgba(28, 26, 23, 0.03);
  overflow: hidden;
}

.notebook-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.dots {
  display: flex;
  gap: 6px;
}

.dots i {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--border-input);
}

.notebook-file {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.notebook-status {
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--green-bg);
  color: var(--green-ink);
  font-family: var(--font-sans);
  font-size: 11.5px;
  white-space: nowrap;
}

.notebook .cell {
  margin: 16px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 12px;
  overflow: hidden;
}

.cell-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 14px;
  background: var(--bg-app);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--faint);
}

.cell-state {
  padding: 2px 9px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-family: var(--font-sans);
  font-size: 11.5px;
  white-space: nowrap;
}

.code {
  margin: 0;
  padding: 16px 18px;
  background: #1c1a17;
  color: #f7f5f1;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.7;
  overflow-x: auto;
  word-break: normal;
}

.code code {
  font-family: inherit;
  white-space: pre;
}

.code .fn {
  color: #e3b8ff;
}

.code .str {
  color: #b8d9b0;
}

.code .kw {
  color: #f0b3a0;
}

.code .cm {
  color: #a09889;
}

.code-mini {
  margin-top: 12px;
  padding: 10px 14px;
  border-radius: 10px;
  font-size: 12px;
  overflow-x: hidden;
}

.code-mini code {
  white-space: pre-wrap;
  word-break: break-all;
}

.output {
  margin: 0 16px 16px;
  padding: 12px 16px;
  border-radius: 12px;
  background: var(--green-bg);
  color: var(--green-ink);
  font-family: var(--font-mono);
  font-size: 14px;
}

.out-label {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-sans);
  font-size: 11.5px;
  color: var(--green-muted);
}

.notebook-small .cell {
  margin: 14px;
}

.notebook-small .output {
  margin: 0 14px 14px;
}

.copy-btn {
  padding: 3px 11px;
  border: 1px solid var(--border-input);
  border-radius: 999px;
  background: var(--card-bg);
  color: var(--muted);
  font: inherit;
  font-size: 12px;
  cursor: pointer;
}

.copy-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ---------- 공통 요소 ---------- */
.eyebrow {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--accent);
}

.eyebrow-blue {
  color: var(--blue-ink);
}

.page-inner > h2 {
  margin: 0 0 22px;
  font-family: var(--font-serif);
  font-size: 30px;
  font-weight: 400;
  line-height: 1.4;
}

.page-inner h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
}

.section-lead {
  margin: -10px 0 18px;
  color: var(--muted);
  font-size: 14.5px;
}

kbd {
  padding: 2px 9px;
  border: 1px solid var(--border-input);
  border-bottom-width: 2px;
  border-radius: 8px;
  background: var(--card-bg);
  font-family: var(--font-mono);
  font-size: 0.9em;
}

.card,
.step,
.timeline li,
.roadmap li,
.flow li:not(.flow-arrow) {
  background: var(--card-bg);
  border: 1px solid var(--border-light);
  border-radius: 18px;
  box-shadow: 0 1px 2px rgba(28, 26, 23, 0.03);
}

.card {
  padding: 24px;
}

.card p {
  margin: 0 0 6px;
  color: var(--muted);
  font-size: 15px;
}

.card .eyebrow {
  margin-bottom: 8px;
}

.card-accent {
  background: var(--accent-soft);
  border-color: transparent;
}

.card-note {
  margin: 10px 0 0;
  font-size: 13px;
  color: var(--faint);
}

.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.card-grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card-grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.split {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  align-items: start;
}

.split.practice {
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: 24px;
}

.split-cell {
  align-items: center;
}

.callout {
  margin-top: 18px;
  padding: 16px 22px;
  border-radius: 16px;
  background: var(--green-bg);
  color: var(--green-ink);
}

.callout strong {
  display: block;
  margin-bottom: 2px;
  font-size: 14px;
}

.callout p {
  margin: 0;
  font-size: 15px;
}

.callout-soft {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.badge {
  display: inline-block;
  margin: 0 0 10px;
  padding: 3px 11px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
}

.badge-green {
  background: var(--green-bg);
  color: var(--green-ink);
}

/* 타임라인 */
.timeline {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.timeline li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 14px;
  font-size: 13.5px;
  color: var(--muted);
}

.timeline li strong {
  font-size: 15px;
  color: var(--ink);
}

.timeline li.is-focus {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.step-no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--accent);
}

/* 파이썬 vs 코랩 */
.flow {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 10px;
  align-items: stretch;
  margin: 0;
  padding: 0;
  list-style: none;
}

.flow li:not(.flow-arrow) {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px;
}

.flow li p {
  margin: 0;
  font-size: 14.5px;
  color: var(--muted);
}

.flow-arrow {
  align-self: center;
  font-size: 20px;
  color: var(--faint);
}

.flow-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
}

.metaphor {
  margin-top: auto;
  padding: 8px 12px;
  border-radius: 10px;
  background: var(--bg-app);
  font-size: 13px;
}

.flow-caption {
  margin: 12px 0 0;
  text-align: center;
  font-size: 13px;
  color: var(--faint);
}

/* 단계 카드 */
.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.step {
  position: relative;
  padding: 22px;
}

.step p {
  margin: 0 0 8px;
  font-size: 14.5px;
  color: var(--muted);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  margin-bottom: 10px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 14px;
}

.step-key {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.step-extra {
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 13px !important;
}

.step-extra code {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink);
}

.step-extra span {
  color: var(--faint);
}

.mini-terminal {
  display: flex;
  flex-direction: column;
  padding: 12px 14px;
  border-radius: 12px;
  background: #1c1a17;
  color: #f7f5f1;
  font-family: var(--font-mono);
  font-size: 13px;
}

.mini-terminal span:last-child {
  color: #b8d9b0;
}

blockquote {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-size: 20px;
  line-height: 1.5;
  color: var(--ink);
}

/* 목록 */
.plain-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.plain-list li {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.plain-list strong {
  font-size: 15px;
}

.plain-list span {
  font-size: 14px;
  color: var(--muted);
}

/* 단축키 */
.shortcut {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 32px;
  align-items: center;
  padding: 32px;
  background: var(--card-bg);
  border: 1px solid var(--border-light);
  border-radius: 18px;
}

.keys {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  color: var(--faint);
}

.keys kbd {
  padding: 14px 24px;
  font-size: 18px;
  color: var(--ink);
  background: var(--bg-app);
}

.shortcut p {
  margin: 0 0 6px;
  color: var(--muted);
}

.shortcut .shortcut-lead {
  font-family: var(--font-serif);
  font-size: 22px;
  color: var(--ink);
}

/* 오류 / 정리 */
.error-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.error-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 20px;
  border-radius: 14px;
  background: var(--card-bg);
  border: 1px solid var(--border-light);
}

.error-card p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

.error-card strong {
  font-size: 17px;
}

.error-card .fix {
  margin-top: 8px;
  padding: 8px 10px;
  border-radius: 10px;
  background: var(--bg-app);
  font-size: 13px;
  color: var(--ink);
}

.error-name {
  align-self: flex-start;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 11.5px;
}

.recap-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.recap-grid li {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 26px 12px;
  border-radius: 18px;
  background: var(--card-bg);
  border: 1px solid var(--border-light);
  text-align: center;
}

.recap-grid span:not(.recap-emoji) {
  font-size: 13.5px;
  color: var(--muted);
}

.recap-grid em {
  margin-top: 8px;
  padding: 2px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-style: normal;
  font-size: 12px;
  font-weight: 600;
}

.recap-emoji {
  font-size: 30px;
}

/* 조건문 설명 */
.branch {
  padding: 20px 22px;
  border-radius: 16px;
  background: var(--card-bg);
  border: 1px solid var(--border-light);
}

.branch p {
  margin: 0 0 6px;
  font-size: 14.5px;
}

.branch-q {
  font-weight: 700;
}

.branch-paths {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 12px 0;
}

.branch-paths > div {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 14px;
  border-radius: 12px;
  font-size: 13.5px;
}

.branch-paths em {
  font-style: normal;
  font-size: 12px;
}

.branch-yes {
  background: var(--green-bg);
  color: var(--green-ink);
}

.branch-no {
  border: 1px dashed var(--border-input);
  color: var(--faint);
}

/* 표 / 예시 */
.mini-table {
  width: 100%;
  margin-top: 10px;
  border-collapse: collapse;
  font-size: 13px;
}

.mini-table th,
.mini-table td {
  padding: 5px 8px;
  border-bottom: 1px solid var(--border-light);
  text-align: left;
}

.mini-table th {
  color: var(--faint);
  font-weight: 600;
}

.mini-bars {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  height: 64px;
  margin-top: 10px;
  padding: 8px 12px 0;
  border-radius: 10px;
  background: var(--bg-app);
}

.mini-bars i {
  flex: 1;
  border-radius: 4px 4px 0 0;
  background: var(--accent);
  opacity: 0.75;
}

.sample {
  margin: 10px 0 0 !important;
  padding: 10px 12px;
  border-radius: 10px;
  background: var(--bg-app);
  font-size: 13px !important;
}

/* 로드맵 */
.roadmap {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.roadmap li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 22px;
}

.roadmap h3 {
  margin: 0;
}

.roadmap p {
  margin: 0;
  font-size: 14.5px;
  color: var(--muted);
}

.rec {
  margin-top: auto;
  padding-top: 8px;
  font-size: 13px;
  color: var(--accent);
}

/* 부록 */
.menu-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin: 0;
  padding: 8px 14px 0;
  list-style: none;
  font-size: 13px;
  color: var(--muted);
}

.menu-bar li {
  padding: 3px 9px;
  border-radius: 8px;
}

.menu-bar .menu-sep {
  margin-left: 12px;
  border: 1px solid var(--border-input);
}

.menu-bar .menu-sep ~ li {
  border: 1px solid var(--border-input);
}

.links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 12px;
  margin: 16px 0 0;
  font-size: 14.5px;
  color: var(--muted);
}

.qa {
  margin-left: auto;
  font-family: var(--font-serif);
  font-size: 20px;
  color: var(--accent);
}

/* JS가 꺼진 경우의 푸터 */
.site-footer {
  padding: 22px 24px;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 12.5px;
  color: var(--faint);
}

.site-footer a {
  color: inherit;
}

/* ---------- 좁은 화면 ---------- */
@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 22px;
  }

  .toc-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  :root {
    --header-h: 52px;
    --pager-h: 56px;
  }

  .site-header {
    padding: 0 16px;
  }

  .pager {
    padding: 0 16px;
    gap: 12px;
  }

  .pager-btn {
    min-width: 76px;
    padding: 9px 12px;
  }

  .page-inner {
    padding: 20px 16px;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-lead {
    font-size: 15.5px;
  }

  .page-inner > h2 {
    font-size: 23px;
    margin-bottom: 16px;
  }

  .timeline,
  .steps,
  .roadmap,
  .split,
  .split.practice,
  .card-grid-3,
  .error-grid {
    grid-template-columns: 1fr;
  }

  .card-grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .card-grid-4 .card {
    padding: 16px;
  }

  .card-grid-4 .card h3 {
    font-size: 15px;
  }

  .card-grid-4 .card p {
    font-size: 13px;
  }

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

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

  .flow-arrow {
    justify-self: center;
    transform: rotate(90deg);
  }

  .shortcut {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 22px;
  }

  .notebook-status {
    display: none;
  }

  .code {
    padding: 14px;
    font-size: 12.5px;
  }

  .hero .code code {
    white-space: pre-wrap;
    word-break: break-all;
  }

  .qa {
    margin-left: 0;
  }
}

/* ---------- 가독성 향상: 글자·카드를 키우고 대비를 높임 ---------- */
:root {
  --faint: #857c6f;
}

.page-inner > h2 {
  margin-bottom: 26px;
  font-size: 36px;
  line-height: 1.35;
}

.eyebrow {
  margin-bottom: 8px;
  font-size: 13px;
}

.hero-title {
  font-size: 56px;
}

.hero-lead {
  font-size: 19px;
  line-height: 1.6;
}

.tag {
  font-size: 14px;
}

.chip {
  padding: 10px 20px;
  font-size: 16px;
}

.page-inner h3 {
  margin-bottom: 10px;
  font-size: 20px;
}

.card {
  padding: 28px;
}

.card p {
  font-size: 17px;
  line-height: 1.65;
}

.card-note {
  font-size: 14.5px;
}

.callout {
  padding: 18px 26px;
}

.callout strong {
  font-size: 15.5px;
}

.callout p {
  font-size: 17px;
}

.section-lead {
  font-size: 16.5px;
}

.step {
  padding: 26px;
}

.step p {
  font-size: 16.5px;
  line-height: 1.6;
}

.step-extra {
  font-size: 14.5px !important;
}

.step-num {
  width: 36px;
  height: 36px;
  font-size: 16px;
}

.timeline li {
  gap: 6px;
  padding: 22px 16px;
  font-size: 15px;
}

.timeline li strong {
  font-size: 18px;
}

.step-no {
  font-size: 12.5px;
}

.flow li:not(.flow-arrow) {
  padding: 26px 22px;
}

.flow li strong {
  font-size: 19px;
}

.flow li p {
  font-size: 16.5px;
}

.flow-label {
  font-size: 13.5px;
}

.metaphor {
  font-size: 14.5px;
}

.plain-list {
  gap: 18px;
}

.plain-list strong {
  font-size: 18px;
}

.plain-list span {
  font-size: 16px;
  line-height: 1.6;
}

.code {
  padding: 18px 22px;
  font-size: 16px;
}

.output {
  font-size: 16px;
}

.cell-head {
  font-size: 13px;
}

.copy-btn {
  padding: 4px 14px;
  font-size: 13px;
}

.code-mini {
  font-size: 13.5px;
}

.shortcut {
  gap: 40px;
  padding: 40px;
}

.shortcut p {
  font-size: 17px;
}

.shortcut .shortcut-lead {
  font-size: 26px;
}

.keys kbd {
  padding: 18px 30px;
  font-size: 22px;
}

blockquote {
  font-size: 23px;
}

.error-card {
  padding: 24px;
}

.error-card strong {
  font-size: 20px;
}

.error-card p {
  font-size: 16.5px;
}

.error-card .fix {
  font-size: 15px;
}

.error-name {
  font-size: 12.5px;
}

.recap-grid li {
  padding: 32px 14px;
}

.recap-grid strong {
  font-size: 19px;
}

.recap-grid span:not(.recap-emoji) {
  font-size: 15.5px;
}

.recap-emoji {
  font-size: 36px;
}

.branch {
  padding: 24px 26px;
}

.branch p {
  font-size: 16.5px;
}

.branch-paths > div {
  font-size: 15.5px;
}

.roadmap li {
  padding: 26px;
}

.roadmap p {
  font-size: 16.5px;
  line-height: 1.6;
}

.rec {
  font-size: 14.5px;
}

.mini-table {
  font-size: 14.5px;
}

.sample {
  font-size: 14.5px !important;
}

.mini-bars {
  height: 80px;
}

.links {
  font-size: 16px;
}

.menu-bar {
  font-size: 14px;
}

.toc-list a {
  font-size: 15.5px;
}

@media (max-width: 760px) {
  .page-inner > h2 {
    font-size: 25px;
  }

  .hero-title {
    font-size: 34px;
  }

  .hero-lead {
    font-size: 16px;
  }

  .card,
  .step,
  .roadmap li {
    padding: 20px;
  }

  .card p,
  .step p {
    font-size: 15.5px;
  }

  .plain-list strong {
    font-size: 16.5px;
  }

  .plain-list span {
    font-size: 15px;
  }

  .code {
    font-size: 13.5px;
  }
}

/* 실습 페이지: 오른쪽 설명을 카드로 만들어 빈 공간을 채움 */
.split.practice {
  align-items: stretch;
}

.split.practice > div:last-child {
  display: flex;
  flex-direction: column;
}

.split.practice > div:last-child > .eyebrow {
  margin-bottom: 10px;
}

.split.practice .plain-list {
  flex: 1;
  gap: 14px;
}

.split.practice .plain-list li {
  flex: 1;
  justify-content: center;
  gap: 6px;
  padding: 18px 24px;
  border: 1px solid var(--border-light);
  border-left: 4px solid var(--accent);
  border-radius: 16px;
  background: var(--card-bg);
}

.split.practice .branch {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* 휴대폰: 너무 작아지지 않도록 일부 페이지를 촘촘하게 */
@media (max-width: 760px) {
  .timeline {
    gap: 8px;
  }

  .timeline li {
    padding: 10px 14px;
    gap: 2px;
    font-size: 14px;
  }

  .timeline li strong {
    font-size: 16px;
  }

  .steps {
    gap: 8px;
  }

  .step {
    padding: 14px 16px;
  }

  .step-num {
    width: 28px;
    height: 28px;
    margin-bottom: 6px;
    font-size: 14px;
  }

  .step h3 {
    margin-bottom: 4px;
    font-size: 17px;
  }

  .step p {
    margin-bottom: 4px;
    font-size: 14.5px;
    line-height: 1.5;
  }

  .callout {
    margin-top: 12px;
    padding: 12px 16px;
  }

  .callout p {
    font-size: 15px;
  }

  .split {
    gap: 10px;
  }

  .split .card {
    padding: 16px 18px;
  }

  .split .card p {
    font-size: 15px;
  }

  blockquote {
    margin-bottom: 8px;
    font-size: 19px;
  }

  .plain-list {
    gap: 10px;
  }
}

/* ---------- 글씨 크기 살짝 줄임 ---------- */
.page-inner > h2 {
  margin-bottom: 22px;
  font-size: 32px;
}

.hero-title {
  font-size: 50px;
}

.hero-lead {
  font-size: 18px;
}

.page-inner h3 {
  font-size: 18.5px;
}

.card p {
  font-size: 16px;
}

.card-note {
  font-size: 14px;
}

.callout p {
  font-size: 16px;
}

.section-lead {
  font-size: 15.5px;
}

.step p {
  font-size: 15.5px;
}

.timeline li {
  font-size: 14px;
}

.timeline li strong {
  font-size: 17px;
}

.flow li strong {
  font-size: 18px;
}

.flow li p {
  font-size: 15.5px;
}

.plain-list strong {
  font-size: 16.5px;
}

.plain-list span {
  font-size: 15px;
}

.code {
  font-size: 15px;
}

.output {
  font-size: 15px;
}

.shortcut .shortcut-lead {
  font-size: 24px;
}

.shortcut p {
  font-size: 16px;
}

.keys kbd {
  padding: 16px 26px;
  font-size: 20px;
}

blockquote {
  font-size: 21px;
}

.error-card strong {
  font-size: 18.5px;
}

.error-card p {
  font-size: 15.5px;
}

.recap-grid strong {
  font-size: 18px;
}

.recap-grid span:not(.recap-emoji) {
  font-size: 15px;
}

.branch p {
  font-size: 15.5px;
}

.roadmap p {
  font-size: 15.5px;
}

/* 휴대폰 크기 최종 지정 (위의 일반 크기보다 우선) */
@media (max-width: 760px) {
  .page-inner > h2 {
    font-size: 24px;
  }

  .hero-title {
    font-size: 34px;
  }

  .hero-lead {
    font-size: 16px;
  }

  .page-inner h3 {
    font-size: 17px;
  }

  .card p,
  .step p {
    font-size: 14.5px;
    line-height: 1.5;
  }

  .step h3 {
    font-size: 16.5px;
  }

  .timeline li {
    font-size: 13.5px;
  }

  .timeline li strong {
    font-size: 16px;
  }

  .plain-list strong {
    font-size: 16px;
  }

  .plain-list span {
    font-size: 14.5px;
  }

  .callout p {
    font-size: 14.5px;
  }

  .code,
  .output {
    font-size: 13px;
  }

  .card {
    padding: 16px 18px;
  }

  .step {
    padding: 14px 16px;
  }

  .card-grid-3 {
    gap: 8px;
  }

  .card-grid-3 .card .code-mini {
    margin-top: 8px;
  }
}

/* ---------- 왼쪽 메뉴: 파워포인트식 페이지 미리보기 ---------- */
.side {
  display: none;
}

.js .workspace {
  display: flex;
  flex: 1;
  min-height: 0;
}

.js .side {
  display: block;
  flex-shrink: 0;
  width: var(--side-w, 25vw);
  min-width: 200px;
  max-width: 50vw;
  overflow-y: auto;
  padding: 12px 10px 16px;
  border-right: 1px solid var(--border);
  background: #ece8df;
}

.side-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.side-list a {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 4px;
  border-radius: 8px;
  color: var(--muted);
  text-decoration: none;
}

.side-list a:hover {
  background: rgba(255, 255, 255, 0.55);
}

.side-num {
  flex-shrink: 0;
  width: 20px;
  padding-top: 2px;
  text-align: right;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--muted);
}

.side-thumb {
  position: relative;
  display: block;
  flex: 1;
  min-width: 0;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--border-input);
  border-radius: 4px;
  background: var(--bg-app);
  box-shadow: 0 1px 2px rgba(28, 26, 23, 0.08);
}

.side-thumb .thumb-inner {
  position: absolute;
  left: 0;
  top: 0;
  margin: 0 !important;
  transform-origin: 0 0;
  pointer-events: none;
  user-select: none;
}

.side-list a[aria-current='true'] {
  background: rgba(91, 42, 140, 0.1);
}

.side-list a[aria-current='true'] .side-thumb {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent);
}

.side-list a[aria-current='true'] .side-num {
  color: var(--accent);
}

@media (min-width: 1101px) {
  .js .toc-btn {
    display: none;
  }
}

@media (max-width: 1100px) {
  .js .side {
    display: none;
  }
}

/* ---------- 균형 점검 후 보정 ---------- */
.nowrap {
  white-space: nowrap;
}

/* 1번: 제목 줄바꿈과 코드 잘림 */
.hero {
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 32px;
}

.hero-title {
  font-size: clamp(34px, 3.5vw, 48px);
  line-height: 1.3;
}

.hero .code code {
  white-space: pre-wrap;
  word-break: keep-all;
}

/* 3번: 작은 코드 상자 */
.code-mini {
  padding: 10px 12px;
  font-size: 12px;
  overflow-x: hidden;
}

.code-mini code {
  white-space: nowrap;
  word-break: normal;
}

/* 18번: 표가 카드 밖으로 잘리지 않도록 */
.mini-table {
  table-layout: fixed;
  font-size: 12.5px;
}

.mini-table th,
.mini-table td {
  padding: 5px 4px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.card-grid-4 .card {
  padding: 22px 20px;
}

.mini-table th:nth-child(1) {
  width: 27%;
}

.mini-table th:nth-child(2) {
  width: 41%;
}

.mini-table th:nth-child(3) {
  width: 32%;
}

.mini-table th,
.mini-table td {
  padding: 5px 2px;
  font-size: 12px;
  text-overflow: clip;
}

/* ---------- 왼쪽 메뉴 너비 조절 손잡이 ---------- */
.side-resizer {
  display: none;
}

.js .side-resizer {
  position: relative;
  z-index: 5;
  display: block;
  flex: 0 0 10px;
  margin: 0 -5px;
  cursor: col-resize;
  touch-action: none;
}

.js .side-resizer::after {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 4px;
  width: 2px;
  background: var(--border-input);
  transition: background 0.15s;
}

.js .side-resizer:hover::after,
.js .side-resizer:focus-visible::after,
.is-resizing .side-resizer::after {
  background: var(--accent);
}

.is-resizing,
.is-resizing * {
  cursor: col-resize !important;
  user-select: none !important;
}

@media (max-width: 1100px) {
  .js .side-resizer {
    display: none;
  }
}