:root {
  --ink: #17212b;
  --muted: #65707b;
  --line: #d8ddd9;
  --paper: #f7f8f5;
  --white: #ffffff;
  --navy: #0d1c2b;
  --navy-soft: #142b3c;
  --teal: #0d827e;
  --teal-soft: #dceeed;
  --amber: #b97824;
  --red: #a94b43;
  --max: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Noto Sans KR", "Segoe UI", system-ui, sans-serif;
  line-height: 1.75;
  letter-spacing: 0;
}

a { color: inherit; }

.site-header {
  align-items: center;
  background: rgba(247, 248, 245, 0.96);
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  padding: 18px max(24px, calc((100vw - var(--max)) / 2));
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  align-items: center;
  display: inline-flex;
  font-size: 15px;
  font-weight: 800;
  gap: 10px;
  text-decoration: none;
}

.brand-mark {
  align-items: center;
  background: var(--navy);
  color: var(--white);
  display: inline-flex;
  font-size: 11px;
  height: 28px;
  justify-content: center;
  letter-spacing: 0.08em;
  width: 28px;
}

.site-nav { display: flex; gap: 26px; }
.site-nav a { color: var(--muted); font-size: 13px; text-decoration: none; }
.site-nav a:hover { color: var(--teal); }

.hero-band {
  background: var(--navy);
  color: var(--white);
  display: grid;
  gap: 70px;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  margin: 0 auto;
  max-width: 1440px;
  min-height: 570px;
  padding: 86px clamp(24px, calc((100vw - var(--max)) / 2), 130px) 74px;
}

.hero-copy, .hero-figure { min-width: 0; }
.hero-copy { align-self: center; max-width: 680px; }
.eyebrow, .section-index, .rail-label { letter-spacing: 0.12em; text-transform: uppercase; }
.eyebrow { color: #9bc7c5; font-size: 12px; font-weight: 700; margin: 0 0 25px; }
h1, h2, h3, p { margin-top: 0; }
h1 { font-size: clamp(38px, 5vw, 70px); letter-spacing: -0.03em; line-height: 1.12; margin-bottom: 28px; }
.hero-summary { color: #d4dfdf; font-size: 18px; max-width: 580px; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 34px; }
.hero-meta span { border: 1px solid #496170; color: #d9e7e8; font-size: 12px; padding: 5px 10px; }
.hero-figure { align-self: center; margin: 0; }
.hero-figure img { display: block; height: auto; max-width: 100%; width: 100%; }
.hero-figure figcaption { color: #aebfc4; font-size: 12px; margin-top: 14px; }

.article-shell {
  display: grid;
  gap: 76px;
  grid-template-columns: minmax(0, 780px) 230px;
  margin: 0 auto;
  max-width: var(--max);
  padding: 92px 24px 130px;
}

.article-lede { font-size: 21px; line-height: 1.8; margin-bottom: 28px; }
.reading-time { border-bottom: 1px solid var(--line); border-top: 1px solid var(--line); color: var(--muted); display: flex; flex-wrap: wrap; font-size: 12px; gap: 20px; justify-content: space-between; padding: 13px 0; }
.article-section { border-top: 1px solid var(--line); margin-top: 80px; padding-top: 28px; }
.section-index { color: var(--teal); font-size: 11px; font-weight: 800; margin-bottom: 13px; }
.article h2, .sources h2, .closing-note h2 { font-size: 30px; letter-spacing: -0.025em; line-height: 1.25; margin-bottom: 24px; }
.article-section p, .closing-note p { color: #3e4a54; font-size: 16px; }
.article a { color: var(--teal); text-underline-offset: 3px; }

.pull-quote { border-left: 4px solid var(--amber); margin: 58px 0; padding: 4px 0 4px 26px; }
.pull-quote p { color: var(--navy); font-size: 24px; font-weight: 700; line-height: 1.5; margin: 0; }

.flow-diagram { align-items: stretch; background: var(--navy); display: flex; gap: 12px; margin: 34px 0; overflow-x: auto; padding: 22px; }
.flow-node { background: #f2f6f3; flex: 1 0 145px; min-height: 112px; padding: 14px; }
.flow-node span { color: var(--teal); display: block; font-size: 11px; font-weight: 800; letter-spacing: 0.1em; }
.flow-node strong { display: block; font-size: 16px; margin-top: 8px; }
.flow-node small { color: var(--muted); display: block; font-size: 11px; margin-top: 5px; }
.flow-arrow { align-self: center; color: #94c8c5; font-size: 22px; }
.code-block { background: #172a37; color: #d6ece9; font-size: 15px; margin: 30px 0 8px; overflow-x: auto; padding: 22px 24px; }
.code-caption { color: var(--muted) !important; font-size: 12px !important; }

.decision-grid { border-top: 1px solid var(--line); margin: 32px 0; }
.decision-row { align-items: baseline; border-bottom: 1px solid var(--line); display: grid; gap: 18px; grid-template-columns: 108px 1fr; padding: 16px 0; }
.decision-row p { margin: 0; }
.decision-tag { font-size: 11px; font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; }
.decision-tag.keep { color: var(--teal); }
.decision-tag.defer { color: var(--red); }
.decision-tag.check { color: var(--amber); }

.beginner-section { background: #edf3f0; border-top: 0; margin-left: -26px; margin-right: -26px; padding: 30px 26px; }
.term-list { border-top: 1px solid #c7d6d1; }
.term-list div { border-bottom: 1px solid #c7d6d1; display: grid; gap: 24px; grid-template-columns: 160px 1fr; padding: 15px 0; }
.term-list strong { color: var(--navy); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 14px; }
.term-list span { color: #42564f; font-size: 14px; }

.next-list { counter-reset: next; list-style: none; margin: 27px 0 0; padding: 0; }
.next-list li { align-items: center; border-bottom: 1px solid var(--line); display: flex; gap: 17px; padding: 15px 0; }
.next-list span { align-items: center; background: var(--navy); color: var(--white); display: inline-flex; flex: 0 0 28px; font-size: 11px; height: 28px; justify-content: center; }

.closing-note { background: var(--navy); color: var(--white); margin-top: 80px; padding: 34px 36px; }
.closing-note .section-index { color: #9bc7c5; }
.closing-note h2 { color: var(--white); }
.closing-note p { color: #d4dfdf; }

.sources { border-top: 1px solid var(--line); margin-top: 80px; padding-top: 28px; }
.sources ul { color: #4d5961; font-size: 14px; padding-left: 20px; }
.sources li + li { margin-top: 8px; }
.source-boundary { color: var(--muted); font-size: 12px; margin-bottom: 0; }

.side-rail { align-self: start; position: sticky; top: 92px; }
.rail-block { border-top: 1px solid var(--line); padding: 18px 0 28px; }
.rail-label { color: var(--teal); font-size: 10px; font-weight: 800; margin-bottom: 10px; }
.rail-block h3 { font-size: 16px; margin-bottom: 8px; }
.rail-block p { color: var(--muted); font-size: 13px; line-height: 1.65; }
.rail-link { border-top: 1px solid var(--line); display: block; font-size: 13px; padding: 11px 0; text-decoration: none; }
.rail-link span { color: var(--teal); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 11px; margin-right: 8px; }
.rail-link:hover { color: var(--teal); }
.rail-note { border: 1px solid #c8d8d4; margin-top: 18px; padding: 16px; }

.site-footer { border-top: 1px solid var(--line); color: var(--muted); display: flex; font-size: 12px; justify-content: space-between; margin: 0 auto; max-width: var(--max); padding: 24px; }
.site-footer a { color: var(--ink); text-decoration: none; }

@media (max-width: 800px) {
  .site-header { padding: 15px 18px; }
  .site-nav { gap: 14px; }
  .site-nav a { font-size: 12px; }
  .hero-band { display: block; min-height: 0; padding: 66px 22px 52px; }
  .hero-figure { margin-top: 45px; }
  .hero-summary { font-size: 16px; }
  .article-shell { display: block; padding: 62px 18px 90px; }
  .side-rail { display: none; }
  .article-lede { font-size: 18px; }
  .article-section { margin-top: 60px; }
  .article h2, .sources h2, .closing-note h2 { font-size: 25px; }
  .flow-diagram { margin-left: -18px; margin-right: -18px; }
  .beginner-section { margin-left: -18px; margin-right: -18px; padding-left: 18px; padding-right: 18px; }
  .term-list div { display: block; }
  .term-list strong { display: block; margin-bottom: 4px; }
  .site-footer { display: block; padding: 20px 18px; }
  .site-footer a { display: block; margin-top: 8px; }
}

/* Archive layout for the learning journal home. Individual articles keep the editorial layout above. */
.archive-shell {
  display: grid;
  gap: 72px;
  grid-template-columns: 250px minmax(0, 720px);
  margin: 0 auto;
  max-width: 1080px;
  padding: 70px 24px 110px;
}

.profile-panel { align-self: start; position: sticky; top: 92px; }
.profile-mark {
  align-items: center;
  background: var(--navy);
  color: var(--white);
  display: flex;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  font-size: 18px;
  font-weight: 800;
  height: 58px;
  justify-content: center;
  margin-bottom: 22px;
  width: 58px;
}
.profile-kicker { color: var(--teal); font-size: 10px; font-weight: 800; letter-spacing: 0.14em; margin-bottom: 13px; }
.profile-panel h1 { color: var(--navy); font-size: 29px; letter-spacing: -0.025em; line-height: 1.28; margin-bottom: 18px; }
.profile-intro { color: #47535b; font-size: 14px; line-height: 1.8; }
.profile-facts { border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; list-style: none; margin: 22px 0; padding: 0; }
.profile-facts li { border-bottom: 1px solid var(--line); padding: 9px 0; }
.profile-external { color: var(--navy); display: inline-block; font-size: 12px; font-weight: 800; text-underline-offset: 4px; }
.profile-external span { color: var(--teal); font-size: 16px; margin-left: 5px; }
.archive-nav { border-top: 1px solid var(--line); margin-top: 38px; padding-top: 17px; }
.archive-nav-link { align-items: center; border-bottom: 1px solid var(--line); color: var(--muted); display: flex; font-size: 12px; gap: 9px; padding: 9px 0; text-decoration: none; }
.archive-nav-link span { color: #9aa4a5; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 10px; min-width: 24px; }
.archive-nav-link:hover, .archive-nav-link.active { color: var(--teal); }
.archive-nav-link.active span { color: var(--teal); }
.profile-note { border-left: 3px solid var(--amber); margin-top: 34px; padding: 5px 0 5px 14px; }
.profile-note .rail-label { margin-bottom: 6px; }
.profile-note p:last-child { color: var(--muted); font-size: 12px; line-height: 1.65; margin: 0; }

.archive-content { min-width: 0; }
.archive-heading { align-items: end; border-bottom: 2px solid var(--navy); display: flex; justify-content: space-between; padding-bottom: 22px; }
.archive-heading .eyebrow { color: var(--teal); margin-bottom: 8px; }
.archive-heading h2 { color: var(--navy); font-size: 48px; letter-spacing: -0.04em; line-height: 1.12; margin: 0; }
.archive-count { color: var(--navy); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 14px; line-height: 1.35; margin: 0; text-align: right; }
.archive-count span { color: var(--muted); font-family: inherit; font-size: 10px; }
.archive-description { color: var(--muted); font-size: 15px; margin: 18px 0 34px; }
.post-card { border-top: 1px solid var(--line); padding: 26px 0 34px; }
.post-card.featured { background: var(--white); border: 1px solid var(--line); border-top: 4px solid var(--teal); padding: 30px 32px 32px; }
.post-card-topline { align-items: center; display: flex; gap: 12px; margin-bottom: 18px; }
.post-number { color: var(--teal); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 12px; font-weight: 800; }
.post-category { color: var(--muted); font-size: 11px; }
.post-card h3 { color: var(--navy); font-size: 30px; letter-spacing: -0.025em; line-height: 1.3; margin-bottom: 10px; }
.post-card h3 a { text-decoration: none; }
.post-card h3 a:hover { color: var(--teal); }
.post-meta { color: var(--muted); display: flex; font-size: 11px; gap: 18px; margin-bottom: 22px; }
.post-excerpt { color: #45515a; font-size: 15px; line-height: 1.85; margin-bottom: 23px; max-width: 630px; }
.tag-list { display: flex; flex-wrap: wrap; gap: 7px; }
.tag-list span { border: 1px solid #cbd5d1; color: #4e6e6b; font-size: 11px; padding: 3px 8px; }
.read-link { color: var(--navy); display: inline-block; font-size: 12px; font-weight: 800; margin-top: 26px; text-decoration: none; }
.read-link span { color: var(--teal); font-size: 17px; margin-left: 6px; }
.read-link:hover { color: var(--teal); }

.shorts-strip, .roadmap-section, .source-note { border-top: 2px solid var(--navy); margin-top: 62px; padding-top: 22px; }
.section-heading-row { align-items: end; display: flex; justify-content: space-between; }
.section-heading-row h3, .source-note h3 { color: var(--navy); font-size: 25px; letter-spacing: -0.02em; line-height: 1.3; margin: 0; }
.section-index { margin-bottom: 8px; }
.section-aside { color: var(--muted); font-size: 11px; }
.shorts-list { border-top: 1px solid var(--line); margin-top: 22px; }
.shorts-list a { align-items: center; border-bottom: 1px solid var(--line); display: grid; gap: 14px; grid-template-columns: 24px minmax(0, 1fr) 120px; padding: 14px 0; text-decoration: none; }
.shorts-list a:hover strong { color: var(--teal); }
.shorts-list a > span { color: var(--teal); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 11px; }
.shorts-list strong { color: var(--navy); font-size: 13px; font-weight: 700; }
.shorts-list small { color: var(--muted); font-size: 11px; text-align: right; }

.roadmap-list { list-style: none; margin: 22px 0 0; padding: 0; }
.roadmap-list li { align-items: start; border-bottom: 1px solid var(--line); display: grid; gap: 15px; grid-template-columns: 28px minmax(0, 1fr) auto; padding: 16px 0; }
.roadmap-list li > span { align-items: center; background: var(--navy); color: var(--white); display: inline-flex; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 10px; height: 26px; justify-content: center; width: 26px; }
.roadmap-list strong { color: var(--navy); display: block; font-size: 14px; margin-bottom: 4px; }
.roadmap-list p { color: var(--muted); font-size: 12px; line-height: 1.65; margin: 0; }
.roadmap-list em { color: var(--teal); font-size: 11px; font-style: normal; padding-top: 2px; }
.source-note p:not(.section-index) { color: var(--muted); font-size: 13px; line-height: 1.8; }
.source-note a { color: var(--teal); text-underline-offset: 3px; }
.source-note .source-boundary { font-size: 11px; margin-top: 16px; }

@media (max-width: 860px) {
  .archive-shell { display: block; padding: 52px 18px 82px; }
  .profile-panel { position: static; }
  .profile-panel h1 { font-size: 27px; }
  .profile-intro { max-width: 600px; }
  .archive-nav { margin-top: 28px; }
  .archive-nav-link { display: inline-flex; border-bottom: 0; margin-right: 15px; }
  .profile-note { margin-bottom: 54px; max-width: 450px; }
  .archive-heading h2 { font-size: 39px; }
  .post-card.featured { padding: 24px 21px 26px; }
  .post-card h3 { font-size: 26px; }
  .shorts-list a { grid-template-columns: 24px minmax(0, 1fr); }
  .shorts-list small { grid-column: 2; text-align: left; }
  .roadmap-list li { grid-template-columns: 28px minmax(0, 1fr); }
  .roadmap-list em { grid-column: 2; }
}