:root {
  color-scheme: dark;
  --bg: #0b0f14;
  --surface: #111820;
  --border: #263241;
  --text: #e6edf3;
  --secondary: #b9c3ce;
  --muted: #8b949e;
  --accent: #36c5b4;
  --display: "Space Grotesk", "Pretendard", sans-serif;
  --body: "Pretendard", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 110px; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.75 var(--body); -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
a:hover { color: var(--accent); }
img { display: block; max-width: 100%; height: auto; }
h1, h2, h3, p, figure { margin: 0; }
h1, h2, h3 { line-height: 1.35; overflow-wrap: anywhere; }
h1, h2 { font-family: var(--display); font-weight: 600; letter-spacing: -.035em; }
h2 { font-size: 25px; }
::selection { color: var(--bg); background: var(--accent); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
[hidden] { display: none !important; }
.accent { color: var(--accent); }
.shell { width: min(100% - 80px, 1080px); margin-inline: auto; }
.skip-link { position: fixed; top: 12px; left: 20px; z-index: 100; padding: 8px 16px; background: var(--accent); color: var(--bg); transform: translateY(-180%); }
.skip-link:focus { transform: translateY(0); color: var(--bg); }
.site-header { position: sticky; top: 0; z-index: 10; background: rgba(11, 15, 20, .97); border-bottom: 1px solid var(--border); }
.nav { display: flex; align-items: center; gap: 36px; min-height: 76px; }
.logo { font: 600 23px/1 var(--display); letter-spacing: -.055em; }
.logo span { color: var(--accent); }
.nav-links { display: flex; align-items: center; gap: 28px; margin-left: auto; }
.nav-links a, .nav-github { display: inline-flex; align-items: center; min-height: 44px; font-size: 13px; color: var(--secondary); }
.nav-github { gap: 7px; }
.nav a:hover, .nav [aria-current] { color: var(--accent); }
.hero { position: relative; padding: 58px 0 49px; border-bottom: 1px solid var(--border); }
.eyebrow, .section-index, .small-label { font: 10px/1.7 var(--mono); letter-spacing: .1em; color: var(--muted); }
.eyebrow { display: flex; align-items: center; gap: 10px; margin-bottom: 23px; }
.status-dot { width: 5px; height: 5px; background: var(--accent); border-radius: 50%; }
.hero h1 { font-size: clamp(41px, 4.7vw, 60px); line-height: 1.05; letter-spacing: -.065em; }
.hero-subtitle { margin-top: 13px; font: 400 27px/1.4 var(--display); letter-spacing: -.025em; }
.hero-topics { max-width: 700px; margin-top: 17px; color: var(--muted); font: 11px/2 var(--mono); }
.hero-topics span { padding-inline: 3px; color: var(--accent); }
.hero-description { margin-top: 24px; color: var(--secondary); font-size: 17px; line-height: 1.9; }
.hero-actions, .inline-links { display: flex; align-items: center; flex-wrap: wrap; gap: 25px; }
.hero-actions { margin-top: 23px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 23px; min-height: 44px; padding: 8px 17px; border: 1px solid var(--border); border-radius: 3px; background: var(--surface); font-size: 13px; }
.button:hover { border-color: var(--accent); }
.text-link { display: inline-flex; align-items: center; gap: 10px; min-height: 44px; font-size: 13px; }
.text-link span { color: var(--accent); }
.hero-margin-note { position: absolute; right: 12px; bottom: 60px; font: 9px var(--mono); letter-spacing: .12em; writing-mode: vertical-rl; color: var(--muted); opacity: .35; }
.reading-grid { display: grid; grid-template-columns: minmax(0, 1fr) 240px; gap: 60px; padding-block: 46px 48px; }
.reading-grid > *, .notebook-sections > * { min-width: 0; }
.section-heading { display: flex; align-items: flex-end; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.section-index { margin-bottom: 8px; }
.compact { min-height: 34px; font-size: 12px; }
.section-description { margin-top: 16px; color: var(--muted); font-size: 14px; line-height: 1.85; word-break: keep-all; overflow-wrap: anywhere; }
.post-list { margin: 25px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--border); }
.post-list:empty { display: none; }
.post-row { position: relative; display: grid; grid-template-columns: 22px minmax(0, 1fr) 18px; gap: 18px; padding: 25px 0; border-bottom: 1px solid var(--border); }
.post-row::before { content: ""; position: absolute; top: 24px; bottom: 24px; left: -12px; width: 2px; background: transparent; }
.post-row:hover::before, .post-row:focus-visible::before { background: var(--accent); }
.post-number, .post-arrow { font: 11px/2 var(--mono); color: var(--muted); }
.post-arrow { align-self: center; font-size: 17px; }
.post-labels { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; margin-bottom: 10px; }
.category-code { color: var(--accent); font: 10px/1.8 var(--mono); }
.badge { padding: 1px 5px; border: 1px solid var(--border); border-radius: 2px; font: 9px/1.7 var(--mono); letter-spacing: .05em; color: var(--secondary); }
.post-content h3 { font-size: 19px; font-weight: 600; letter-spacing: -.025em; color: #f0f6fc; }
.post-content p { margin-top: 8px; font-size: 13px; line-height: 1.8; color: var(--muted); word-break: keep-all; overflow-wrap: anywhere; }
.post-row:hover h3, .post-row:focus-visible h3 { color: var(--accent); }
.post-meta, .topic-tags { display: flex; flex-wrap: wrap; gap: 8px 14px; font: 10px/1.9 var(--mono); color: var(--muted); }
.post-meta { margin-top: 17px; }
.post-meta time { margin-right: 6px; }
.category-sidebar { border-left: 1px solid var(--border); padding-left: 28px; }
.category-sidebar h2 { font-size: 20px; }
.category-list { display: grid; margin-top: 17px; }
.category-list a { display: flex; justify-content: space-between; align-items: center; gap: 10px; min-height: 39px; color: var(--secondary); font-size: 12px; }
.category-list a:hover { color: var(--accent); }
.category-list a span { color: var(--muted); font-size: 11px; }
.topic-tags { gap: 6px 12px; margin-top: 23px; padding-top: 19px; border-top: 1px solid var(--border); overflow-wrap: anywhere; }
.notebook-sections { display: grid; grid-template-columns: 1fr 1fr; border-block: 1px solid var(--border); }
.notebook-sections > section { padding-block: 40px; }
.notebook-sections > section:first-child { padding-right: 50px; }
.notebook-sections > section + section { padding-left: 50px; border-left: 1px solid var(--border); }
.empty-note { margin-block: 23px 10px; padding: 16px 18px; border-left: 2px solid var(--border); background: var(--surface); }
.empty-note p { margin-top: 5px; font-size: 13px; color: var(--secondary); overflow-wrap: anywhere; }
.about-section { display: grid; grid-template-columns: 1fr 1.2fr; gap: 50px; padding-block: 46px 54px; }
.about-copy > p { color: var(--secondary); font-size: 14px; line-height: 1.9; word-break: keep-all; overflow-wrap: anywhere; }
.inline-links { gap: 24px; margin-top: 12px; }
.footer { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 84px; border-top: 1px solid var(--border); font: 10px/1.8 var(--mono); color: var(--muted); }
.footer a { display: inline-flex; align-items: center; gap: 10px; min-height: 44px; }

/* Archive: static rows remain readable when scripting is unavailable. */
.archive-header { padding: 50px 0 21px; }
.archive-header h1 { font-size: clamp(34px, 4vw, 44px); }
.archive-header .section-description { max-width: 620px; margin-top: 14px; line-height: 1.65; }
.archive-main { min-height: calc(100vh - 162px); padding-bottom: 60px; }
.filter-nav { display: flex; flex-wrap: wrap; gap: 6px 22px; padding-block: 12px 24px; border-bottom: 1px solid var(--border); }
.filter-nav a { display: inline-flex; align-items: center; min-height: 38px; padding: 5px 0; border-bottom: 2px solid transparent; color: var(--muted); font-size: 12px; }
.filter-nav a:hover { color: var(--accent); }
.filter-nav [aria-current] { color: var(--accent); border-bottom-color: var(--accent); }
.archive-results { max-width: 800px; padding-top: 29px; }
.archive-results h2 { font-size: 20px; }
.empty-results { padding-block: 29px; color: var(--muted); font-size: 13px; line-height: 1.75; word-break: keep-all; overflow-wrap: anywhere; }
.empty-results .empty-title { margin-bottom: 7px; color: var(--secondary); font: 500 18px/1.5 var(--display); letter-spacing: -.02em; }
.recent-empty { margin-top: 24px; border-block: 1px solid var(--border); }

/* Article measure is 780px; only code blocks scroll horizontally. */
.article-shell { width: min(100% - 80px, 780px); margin-inline: auto; padding-block: 34px 66px; }
.back-link { color: var(--muted); }
.article-header { padding-block: 27px 25px; border-bottom: 1px solid var(--border); }
.article-header h1 { font-size: clamp(28px, 4vw, 40px); word-break: keep-all; }
.article-header .post-meta { font-size: 11px; }
.sample-notice { margin-block: 26px 36px; padding: 15px 18px; background: var(--surface); border-left: 2px solid var(--accent); color: var(--secondary); font-size: 14px; }
.sample-notice strong { color: var(--accent); }
.article-body { font-size: 17px; line-height: 1.95; color: var(--secondary); overflow-wrap: anywhere; }
.article-body h2 { margin-block: 38px 13px; color: var(--text); font-size: 25px; }
.article-body p + p { margin-top: 16px; }
.article-body ul { padding-left: 24px; }
.article-body li + li { margin-top: 8px; }
.article-body a { color: var(--accent); text-decoration: underline; text-underline-offset: 4px; }
.article-body code { font: .82em/1.8 var(--mono); }
.code-block { margin-block: 24px; border: 1px solid var(--border); border-radius: 4px; background: var(--surface); overflow: hidden; }
.code-label { padding: 8px 17px; border-bottom: 1px solid var(--border); font: 10px/1.8 var(--mono); color: var(--muted); }
.code-block pre { margin: 0; padding: 19px; max-width: 100%; overflow-x: auto; white-space: pre; overscroll-behavior-x: contain; tab-size: 2; }
.code-block code { font-size: 12px; color: var(--text); }
.article-body figure { margin-block: 26px; }
.image-placeholder { display: grid; place-content: center; min-height: 150px; padding: 24px; border: 1px dashed var(--border); background: var(--surface); font: 11px var(--mono); letter-spacing: .08em; color: var(--muted); }
.article-body figcaption { margin-top: 9px; font-size: 12px; color: var(--muted); }
.article-end { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px; margin-top: 42px; padding-top: 20px; border-top: 1px solid var(--border); color: var(--muted); font-size: 12px; }

@media (max-width: 1080px) {
  .reading-grid { gap: 36px; grid-template-columns: minmax(0, 1fr) 215px; }
  .category-sidebar { padding-left: 22px; }
  .notebook-sections > section:first-child { padding-right: 32px; }
  .notebook-sections > section + section { padding-left: 32px; }
}
@media (max-width: 800px) {
  .shell, .article-shell { width: calc(100% - 48px); }
  .article-shell { max-width: 780px; }
  .nav { gap: 24px; }
  .nav-links { gap: 19px; }
  .hero { padding-top: 43px; }
  .hero-margin-note { display: none; }
  .reading-grid { grid-template-columns: minmax(0, 1fr); gap: 36px; }
  .category-sidebar { border-left: 0; border-top: 1px solid var(--border); padding: 26px 0 0; }
  .category-list { grid-template-columns: 1fr 1fr; column-gap: 32px; }
  .topic-tags { margin-top: 14px; }
  .notebook-sections > section:first-child { padding-right: 23px; }
  .notebook-sections > section + section { padding-left: 23px; }
  .notebook-sections h2 { font-size: 22px; }
  .about-section { grid-template-columns: 1fr; gap: 22px; }
}
@media (max-width: 560px) {
  html { scroll-padding-top: 130px; }
  .shell, .article-shell { width: calc(100% - 40px); }
  .nav { min-height: 99px; display: grid; grid-template-columns: 1fr auto; column-gap: 20px; row-gap: 0; padding-block: 10px 5px; }
  .logo { font-size: 22px; }
  .nav-github { justify-self: end; grid-column: 2; grid-row: 1; }
  .nav-links { grid-column: 1 / -1; grid-row: 2; justify-content: space-between; width: 100%; gap: 12px; margin: 0; }
  .nav-links a { min-height: 39px; font-size: 12px; }
  .hero { padding-block: 33px 32px; }
  .eyebrow { font-size: 9px; margin-bottom: 24px; }
  .hero h1 { font-size: 45px; }
  .hero-subtitle { font-size: 23px; }
  .hero-topics { max-width: 330px; font-size: 10px; line-height: 2.1; }
  .hero-description { margin-top: 23px; font-size: 16px; }
  .hero-actions { gap: 18px; margin-top: 21px; }
  .hero-actions .text-link { font-size: 12px; gap: 5px; }
  .button { gap: 13px; padding-inline: 12px; font-size: 12px; }
  h2 { font-size: 23px; }
  .reading-grid { padding-block: 32px; }
  .section-index { font-size: 9px; }
  .section-description { font-size: 13px; }
  .post-row { grid-template-columns: 18px minmax(0, 1fr) 14px; gap: 10px; padding-block: 23px; }
  .post-row::before { left: -9px; }
  .post-content h3 { font-size: 18px; line-height: 1.55; word-break: keep-all; }
  .post-meta { gap: 5px 10px; font-size: 9px; }
  .category-list { column-gap: 19px; }
  .category-list a { min-height: 44px; font-size: 11px; }
  .notebook-sections { grid-template-columns: 1fr; }
  .notebook-sections > section:first-child { padding: 30px 0; }
  .notebook-sections > section + section { padding: 30px 0; border-left: 0; border-top: 1px solid var(--border); }
  .about-section { grid-template-columns: 1fr; padding-block: 32px 37px; }
  .about-copy > p { font-size: 13px; }
  .footer { flex-wrap: wrap; padding-block: 16px; gap: 3px 12px; font-size: 9px; }
  .footer > p:nth-child(2) { display: none; }
  .archive-header { padding-top: 32px; }
  .filter-nav { gap: 3px 20px; }
  .filter-nav a { min-height: 44px; font-size: 11px; }
  .article-shell { padding-top: 22px; }
  .article-header { padding-top: 22px; }
  .article-header h1 { font-size: 29px; line-height: 1.5; }
  .article-body { font-size: 16px; }
  .article-body h2 { font-size: 23px; }
  .sample-notice { font-size: 13px; }
  .code-block pre { padding: 15px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}