:root {
  --bg: #f4f8f7;
  --surface: #fff;
  --surface-soft: #edf6f4;
  --text: #172328;
  --muted: #5d6c70;
  --border: #ccdcd8;
  --brand: #138477;
  --brand-dark: #075f57;
  --navy: #102f46;
  --sky: #dff2f7;
  --coral: #e56f5b;
  --coral-soft: #fff0eb;
  --gold: #c78b28;
  --gold-soft: #fff7df;
  --violet: #7358a5;
  --violet-soft: #f3effb;
  --blue: #2e72b8;
  --blue-soft: #eaf4ff;
  --mint: #24a98f;
  --mint-soft: #e7faf5;
  --page-glow-1: rgb(19 132 119 / 12%);
  --page-glow-2: rgb(229 111 91 / 10%);
  --site-header-background: linear-gradient(105deg, #0e695f, #102f46 72%);
  --hero-background:
    linear-gradient(105deg, transparent 0 68%, rgb(229 111 91 / 16%) 68% 69%, transparent 69%),
    radial-gradient(circle at 86% 18%, rgb(255 255 255 / 13%) 0 5rem, transparent 5.1rem),
    radial-gradient(circle at 91% 15%, transparent 0 7.6rem, rgb(255 255 255 / 8%) 7.7rem 7.8rem, transparent 7.9rem),
    linear-gradient(132deg, #0b8b78 0%, #126c72 38%, #174c70 68%, #392f68 112%);
  --toc-background: linear-gradient(135deg, var(--mint-soft), var(--sky) 55%, var(--violet-soft));
  --flow-background: linear-gradient(135deg, var(--mint-soft), var(--sky) 52%, var(--violet-soft));
  --code-background: linear-gradient(145deg, #10242c, #142f38);
  --table-header-background: linear-gradient(110deg, #0d766b, #174c70);
  --previous-background: linear-gradient(135deg, var(--mint-soft), var(--sky));
  --next-background: linear-gradient(135deg, var(--coral-soft), var(--violet-soft));
  --code-bg: #10242c;
  --code-text: #e4f2ef;
  --content-width: 940px;
  --shadow: 0 20px 55px rgb(16 47 70 / 10%);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b171b;
    --surface: #122329;
    --surface-soft: #173238;
    --text: #eef4fa;
    --muted: #a9b8c8;
    --border: #2d474b;
    --brand: #66d3c2;
    --brand-dark: #8ee2d5;
    --navy: #d7edf5;
    --sky: #183944;
    --coral: #ff9a87;
    --coral-soft: #452d2c;
    --gold: #f0c36c;
    --gold-soft: #423922;
    --violet: #c2a9ef;
    --violet-soft: #302943;
    --blue: #7db9f3;
    --blue-soft: #1d3248;
    --mint: #6bdac3;
    --mint-soft: #193c38;
    --shadow: none;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 8% 5%, var(--page-glow-1), transparent 24rem),
    radial-gradient(circle at 92% 15%, var(--page-glow-2), transparent 22rem),
    var(--bg);
  font-family: Pretendard, "Noto Sans KR", system-ui, -apple-system,
    BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.8;
  overflow-wrap: anywhere;
  word-break: keep-all;
}

a { color: var(--brand-dark); text-underline-offset: .2em; }
a:hover { text-decoration-thickness: .14em; }
a:focus-visible, button:focus-visible {
  outline: 3px solid var(--brand);
  outline-offset: 3px;
}
.shared-portal-menu { display: contents; }
.site-nav a.active {
  font-weight: 900;
  text-decoration: underline;
  text-decoration-thickness: .16em;
}

.lecture-community-comments {
  width: min(100%, var(--content-width));
  margin: 2rem auto 4rem;
  padding: clamp(1.2rem, 4vw, 2rem);
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.lecture-community-comments > header { margin-bottom: 1.25rem; }
.lecture-community-comments > header p { margin: 0; color: var(--brand); font-size: .72rem; font-weight: 900; letter-spacing: .16em; }
.lecture-community-comments > header h2 { margin: .2rem 0; color: var(--navy); font-size: 1.7rem; }
.lecture-community-comments > header span { color: var(--muted); font-size: .9rem; }
.lecture-community-comments form { display: grid; grid-template-columns: 1fr 7rem; overflow: hidden; border: 1px solid var(--border); border-radius: 12px; }
.lecture-community-comments textarea { min-height: 6rem; padding: 1rem; border: 0; resize: vertical; color: var(--text); background: var(--surface-soft); font: inherit; }
.lecture-community-comments form button,.comment-load-more { border: 0; color: #fff; background: linear-gradient(135deg, var(--mint), var(--blue), var(--violet)); font-weight: 800; cursor: pointer; }
.lecture-community-comments form button:disabled { opacity: .55; cursor: wait; }
.comment-login-notice { padding: 1rem; border-radius: 12px; background: var(--surface-soft); color: var(--muted); }
.comment-login-notice a { font-weight: 900; }
.comment-status { min-height: 1.5rem; color: var(--muted); font-size: .85rem; }
.lecture-comment { position: relative; padding: 1.15rem .2rem; border-top: 1px solid var(--border); }
.lecture-comment > div:first-child { display: flex; justify-content: space-between; gap: 1rem; }
.lecture-comment time { color: var(--muted); font-size: .75rem; }
.lecture-comment > p { margin: .45rem 0 0; white-space: pre-wrap; }
.comment-actions { display: flex; gap: .45rem; margin-top: .6rem; }
.comment-actions button { padding: .3rem .65rem; border: 1px solid var(--border); border-radius: 7px; color: var(--muted); background: var(--surface-soft); cursor: pointer; }
.comment-load-more { display: block; margin: 1rem auto 0; padding: .65rem 1.1rem; border-radius: 9px; }
.comment-load-more[hidden] { display: none; }
@media (max-width: 640px) { .lecture-community-comments form { grid-template-columns: 1fr; } .lecture-community-comments form button { min-height: 2.8rem; } }

img, video { display: block; max-width: 100%; height: auto; }

.skip-link {
  position: fixed;
  z-index: 1000;
  top: .75rem;
  left: .75rem;
  padding: .6rem .9rem;
  color: #fff;
  background: #111;
  transform: translateY(-200%);
}
.skip-link:focus { transform: none; }

.site-header {
  border-bottom: 1px solid rgb(255 255 255 / 18%);
  color: #fff;
  background: var(--site-header-background);
  box-shadow: 0 6px 20px rgb(16 47 70 / 13%);
}

.header-inner, .footer-inner {
  width: min(calc(100% - 2rem), 1120px);
  margin-inline: auto;
}

.header-inner {
  display: flex;
  min-height: 64px;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  color: #fff;
  font-size: 1.2rem;
  font-weight: 800;
  text-decoration: none;
}

.site-nav, .footer-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
}
.site-nav { font-size: .94rem; }
.site-nav a { color: #d7eeeb; font-weight: 700; text-decoration: none; }
.site-nav a:hover { color: #fff; }
.theme-picker {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding-left: .25rem;
  color: #fff;
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .04em;
}
.theme-picker select {
  min-height: 2rem;
  padding: .3rem .75rem;
  border: 2px solid #78d2c2;
  border-radius: 999px;
  color: #102f46;
  background: #dff8f2;
  font: inherit;
  font-weight: 900;
  cursor: pointer;
  box-shadow: 0 3px 10px rgb(0 0 0 / 20%), inset 0 0 0 1px rgb(255 255 255 / 55%);
}
.theme-picker select option { color: #102f46; background: #dff8f2; }
.theme-picker select:focus-visible { outline: 3px solid #fff; outline-offset: 2px; }

.page-shell {
  width: min(calc(100% - 2rem), 1120px);
  margin: 2rem auto 4rem;
}

.breadcrumbs {
  max-width: var(--content-width);
  margin: 0 auto 1rem;
  color: var(--muted);
  font-size: .88rem;
}
.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.breadcrumbs li:not(:last-child)::after {
  margin-left: .35rem;
  color: var(--muted);
  content: "/";
}

.article-card {
  max-width: var(--content-width);
  margin-inline: auto;
  padding: clamp(1.25rem, 4vw, 3.5rem);
  border: 1px solid var(--border);
  overflow: hidden;
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.article-header {
  position: relative;
  margin: calc(clamp(1.25rem, 4vw, 3.5rem) * -1) calc(clamp(1.25rem, 4vw, 3.5rem) * -1) 0;
  padding: clamp(2.4rem, 7vw, 5rem) clamp(1.25rem, 4vw, 3.5rem) 2.7rem;
  color: #fff;
  background: var(--hero-background);
}
.article-header::after {
  position: absolute;
  right: -2.5rem;
  bottom: -4.5rem;
  width: 12rem;
  height: 12rem;
  border: 1px solid rgb(255 255 255 / 14%);
  border-radius: 50%;
  content: "";
}
.eyebrow {
  display: inline-flex;
  margin: 0 0 1rem;
  padding: .35rem .7rem;
  border: 1px solid rgb(255 255 255 / 25%);
  border-radius: 999px;
  color: #d8f7f2;
  background: rgb(255 255 255 / 9%);
  font-size: .88rem;
  font-weight: 800;
  letter-spacing: .04em;
  text-transform: uppercase;
}

h1, h2, h3 { line-height: 1.35; scroll-margin-top: 1.5rem; }
h1 {
  max-width: 12em;
  margin: 0;
  color: #fff;
  font-family: "Noto Serif KR", "Nanum Myeongjo", Georgia, serif;
  font-size: clamp(2.35rem, 7vw, 4.2rem);
  font-weight: 850;
  line-height: 1.18;
  letter-spacing: -.055em;
  text-wrap: balance;
  text-shadow: 0 4px 22px rgb(0 0 0 / 18%);
}
.description { max-width: 39rem; margin: 1.25rem 0 0; color: #d8e9ed; font-size: 1.08rem; }
.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem 1rem;
  margin: 1rem 0 0;
  color: #c4dddd;
  font-size: .9rem;
}
.article-header a { color: #bff5ec; font-weight: 750; }
.article-header a:hover { color: #fff; }
.hero-image {
  margin: 1.5rem 0 0;
  border-radius: 14px;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: var(--surface-soft);
}

.table-of-contents {
  position: relative;
  margin: 2.5rem 0 3rem;
  padding: 1.35rem 1.5rem 1.35rem 3.8rem;
  border: 1px solid #b9dcd6;
  border-radius: 16px;
  background: var(--toc-background);
}
.table-of-contents::before {
  position: absolute;
  top: 1.25rem;
  left: 1.25rem;
  display: grid;
  width: 1.8rem;
  height: 1.8rem;
  place-items: center;
  border-radius: 8px;
  color: #fff;
  background: linear-gradient(135deg, var(--brand), var(--blue));
  box-shadow: 0 5px 12px rgb(19 132 119 / 23%);
  content: "☰";
  font-size: .8rem;
}
.table-of-contents h2 {
  margin: 0 0 1rem;
  color: var(--navy);
  font-size: 1.15rem;
  letter-spacing: -.02em;
}
.table-of-contents :is(ol, ul) {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .45rem .8rem;
  margin: 0;
  padding: 0;
  counter-reset: lesson-toc;
  list-style: none;
}
.table-of-contents li {
  display: grid;
  grid-template-columns: 1.7rem minmax(0, 1fr);
  align-items: start;
  gap: .55rem;
  min-width: 0;
  padding: .55rem .65rem;
  border: 1px solid transparent;
  border-radius: 10px;
  background: rgb(255 255 255 / 52%);
  counter-increment: lesson-toc;
  transition: border-color .16s ease, background .16s ease, transform .16s ease;
}
.table-of-contents li::before {
  display: grid;
  width: 1.7rem;
  height: 1.7rem;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--brand);
  content: counter(lesson-toc, decimal-leading-zero);
  font-size: .62rem;
  font-weight: 900;
  line-height: 1;
}
.table-of-contents li.toc-unnumbered {
  grid-template-columns: minmax(0, 1fr);
  counter-increment: none;
  background: rgb(255 255 255 / 30%);
}
.table-of-contents li.toc-unnumbered::before { display: none; }
.table-of-contents li.toc-unnumbered a {
  padding-left: .15rem;
  color: var(--brand-dark);
  font-weight: 850;
}
.table-of-contents li:hover {
  border-color: var(--border);
  background: var(--surface);
  transform: translateX(2px);
}
.table-of-contents a {
  min-width: 0;
  padding-top: .12rem;
  color: var(--text);
  font-size: .88rem;
  font-weight: 680;
  line-height: 1.45;
  text-decoration: none;
}
.table-of-contents a:hover { color: var(--brand-dark); }

.article-body h2 {
  position: relative;
  margin: 3.8rem 0 1.2rem;
  padding: .8rem 1rem .8rem 1.15rem;
  border-left: 6px solid var(--brand);
  border-radius: 0 12px 12px 0;
  color: var(--navy);
  background: linear-gradient(90deg, var(--surface-soft), transparent 88%);
  font-size: clamp(1.45rem, 4vw, 2rem);
  letter-spacing: -.025em;
}
.article-body h2:nth-of-type(5n + 2) { border-left-color: var(--coral); background: linear-gradient(90deg, var(--coral-soft), transparent 88%); }
.article-body h2:nth-of-type(5n + 3) { border-left-color: var(--gold); background: linear-gradient(90deg, var(--gold-soft), transparent 88%); }
.article-body h2:nth-of-type(5n + 4) { border-left-color: var(--violet); background: linear-gradient(90deg, var(--violet-soft), transparent 88%); }
.article-body h2:nth-of-type(5n + 5) { border-left-color: var(--blue); background: linear-gradient(90deg, var(--blue-soft), transparent 88%); }
.article-body h3 { margin: 2rem 0 .75rem; color: var(--brand-dark); font-size: 1.25rem; }
.article-body :is(p, ul, ol, table, pre, blockquote) { margin-block: 1rem; }
.article-body > p { max-width: 72ch; }
.article-body strong { color: var(--navy); }

.article-body .learning-objectives {
  margin: 0 0 2.5rem;
  padding: clamp(1.1rem, 3vw, 1.7rem);
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--flow-background);
  box-shadow: var(--shadow);
}
.article-body .learning-objectives h2 {
  margin: 0 0 .8rem;
  background: rgb(255 255 255 / 38%);
}
.article-body .learning-objectives > p {
  margin: 0 0 1rem;
  color: var(--muted);
  font-weight: 700;
}
.article-body .learning-objectives ul {
  display: grid;
  gap: .75rem;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: learning-objective;
}
.article-body .learning-objectives li {
  position: relative;
  min-height: 3.5rem;
  padding: .85rem 1rem .85rem 3.65rem;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  counter-increment: learning-objective;
}
.article-body .learning-objectives li::before {
  content: counter(learning-objective, decimal-leading-zero);
  position: absolute;
  top: .72rem;
  left: .8rem;
  width: 2.05rem;
  height: 2.05rem;
  display: grid;
  place-items: center;
  border-radius: 9px;
  color: #fff;
  background: linear-gradient(135deg, var(--mint), var(--blue), var(--violet));
  font-size: .75rem;
  font-weight: 900;
}
.flow {
  display: flex;
  margin: 1.8rem 0;
  padding: 1.2rem;
  border: 1px solid #b9dcd6;
  border-radius: 16px;
  background: var(--flow-background);
}
.flow-step {
  position: relative;
  display: flex;
  min-width: 0;
  align-items: center;
  gap: .8rem;
  padding: .9rem 1rem;
  border: 1px solid rgb(19 132 119 / 22%);
  border-radius: 12px;
  background: var(--surface);
  box-shadow: 0 5px 14px rgb(16 47 70 / 7%);
}
.flow-step:nth-child(5n + 2) { border-color: rgb(229 111 91 / 35%); background: var(--coral-soft); }
.flow-step:nth-child(5n + 3) { border-color: rgb(199 139 40 / 35%); background: var(--gold-soft); }
.flow-step:nth-child(5n + 4) { border-color: rgb(115 88 165 / 32%); background: var(--violet-soft); }
.flow-step:nth-child(5n + 5) { border-color: rgb(46 114 184 / 32%); background: var(--blue-soft); }
.flow-number {
  display: grid;
  width: 2rem;
  height: 2rem;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--brand);
  font-size: .72rem;
  font-weight: 850;
}
.flow-step:nth-child(5n + 2) .flow-number { background: var(--coral); }
.flow-step:nth-child(5n + 3) .flow-number { background: var(--gold); }
.flow-step:nth-child(5n + 4) .flow-number { background: var(--violet); }
.flow-step:nth-child(5n + 5) .flow-number { background: var(--blue); }
.flow-label { color: var(--navy); font-weight: 750; line-height: 1.55; }
.flow-vertical { flex-direction: column; gap: 2rem; }
.flow-vertical .flow-step:not(:first-child)::before {
  position: absolute;
  top: -1.72rem;
  left: 50%;
  color: var(--coral);
  content: "↓";
  font-size: 1.25rem;
  font-weight: 900;
  transform: translateX(-50%);
}
.flow-horizontal { align-items: stretch; gap: 2rem; }
.flow-horizontal .flow-step { flex: 1 1 0; justify-content: center; text-align: center; }
.flow-horizontal .flow-step:not(:first-child)::before {
  position: absolute;
  top: 50%;
  left: -1.45rem;
  color: var(--coral);
  content: "→";
  font-size: 1.25rem;
  font-weight: 900;
  transform: translateY(-50%);
}
.article-body blockquote {
  margin-inline: 0;
  padding: 1rem 1.2rem 1rem 1.35rem;
  border: 1px solid #f0c5bb;
  border-left: 5px solid var(--coral);
  border-radius: 0 12px 12px 0;
  color: var(--text);
  background: var(--coral-soft);
}
.article-body code {
  padding: .12em .34em;
  border-radius: 5px;
  background: var(--surface-soft);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: .9em;
  word-break: break-word;
}
.article-body pre {
  overflow-x: auto;
  padding: 1rem;
  border: 1px solid #294952;
  border-radius: 14px;
  color: var(--code-text);
  background:
    linear-gradient(90deg, var(--mint) 0 33%, var(--blue) 33% 66%, var(--violet) 66%) top / 100% 3px no-repeat,
    var(--code-background);
  box-shadow: 0 12px 24px rgb(16 47 70 / 13%);
  line-height: 1.55;
  tab-size: 2;
}
.article-body pre code {
  padding: 0;
  color: inherit;
  background: transparent;
  font-size: .88rem;
  word-break: normal;
}

.table-scroll { overflow-x: auto; margin-block: 1rem; }
.article-body table { overflow: hidden; width: 100%; border-collapse: separate; border-spacing: 0; border: 1px solid var(--border); border-radius: 12px; font-size: .94rem; }
.article-body th, .article-body td {
  padding: .7rem;
  border: 1px solid var(--border);
  vertical-align: top;
  text-align: left;
}
.article-body th { color: #fff; background: var(--table-header-background); }
.article-body tbody tr:nth-child(even) { background: var(--surface-soft); }
.article-body tbody tr:hover { background: var(--gold-soft); }

.lesson-glossary {
  margin: 4rem 0 3rem;
  padding: clamp(1.25rem, 4vw, 2.2rem);
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--flow-background);
  box-shadow: 0 14px 30px rgb(16 47 70 / 8%);
}
.glossary-heading {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: end;
  margin-bottom: 1.4rem;
}
.glossary-heading p {
  grid-column: 1 / -1;
  margin: 0;
  color: var(--brand-dark);
  font-size: .72rem;
  font-weight: 900;
  letter-spacing: .14em;
}
.glossary-heading h2 {
  margin: .2rem 0 0;
  padding: 0;
  border: 0;
  color: var(--navy);
  background: none;
  font-family: "Noto Serif KR", "Nanum Myeongjo", Georgia, serif;
  font-size: clamp(1.8rem, 5vw, 2.5rem);
}
.glossary-heading > a { font-size: .84rem; font-weight: 800; }
.glossary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .8rem;
  margin: 0;
}
.glossary-entry {
  padding: 1rem;
  border: 1px solid rgb(19 132 119 / 24%);
  border-top: 5px solid var(--brand);
  border-radius: 13px;
  background: linear-gradient(180deg, var(--mint-soft) 0 3.4rem, var(--surface) 3.4rem);
  box-shadow: 0 6px 15px rgb(16 47 70 / 7%);
}
.glossary-entry:nth-child(5n + 2) { border-top-color: var(--coral); background: linear-gradient(180deg, var(--coral-soft) 0 3.4rem, var(--surface) 3.4rem); }
.glossary-entry:nth-child(5n + 3) { border-top-color: var(--gold); background: linear-gradient(180deg, var(--gold-soft) 0 3.4rem, var(--surface) 3.4rem); }
.glossary-entry:nth-child(5n + 4) { border-top-color: var(--violet); background: linear-gradient(180deg, var(--violet-soft) 0 3.4rem, var(--surface) 3.4rem); }
.glossary-entry:nth-child(5n + 5) { border-top-color: var(--blue); background: linear-gradient(180deg, var(--blue-soft) 0 3.4rem, var(--surface) 3.4rem); }
.glossary-entry dt { color: var(--navy); font-size: 1.05rem; font-weight: 900; }
.glossary-entry dt span { display: block; color: var(--brand-dark); font-size: .72rem; font-weight: 700; }
.glossary-entry dd { margin: .5rem 0 0; color: var(--muted); font-size: .88rem; line-height: 1.65; }

.glossary-page { width: min(calc(100% - 2rem), 1120px); margin: 3rem auto 5rem; }
.glossary-index-header {
  padding: clamp(2rem, 7vw, 4.5rem);
  border-radius: 24px;
  color: #fff;
  background: var(--hero-background);
  box-shadow: var(--shadow);
}
.glossary-index-header > p { margin: 0 0 .7rem; color: #d8f7f2; font-size: .75rem; font-weight: 900; letter-spacing: .14em; }
.glossary-index-header h1 { max-width: 13em; }
.glossary-index-header span { display: block; margin-top: 1rem; color: #d8e9ed; }
.glossary-index-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; margin-top: 1.5rem; }
.glossary-index-entry {
  padding: 1.4rem;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--surface);
  box-shadow: 0 8px 20px rgb(16 47 70 / 6%);
}
.glossary-index-entry:nth-child(5n + 1) { border-top: 4px solid var(--brand); }
.glossary-index-entry:nth-child(5n + 2) { border-top: 4px solid var(--coral); }
.glossary-index-entry:nth-child(5n + 3) { border-top: 4px solid var(--gold); }
.glossary-index-entry:nth-child(5n + 4) { border-top: 4px solid var(--violet); }
.glossary-index-entry:nth-child(5n + 5) { border-top: 4px solid var(--blue); }
.glossary-term { margin: 0; color: var(--brand-dark); font-size: .75rem; font-weight: 900; letter-spacing: .08em; text-transform: uppercase; }
.glossary-index-entry h2 { margin: .2rem 0 .65rem; color: var(--navy); font-size: 1.25rem; }
.glossary-index-entry > p:not(.glossary-term) { margin: 0; color: var(--muted); font-size: .9rem; }
.glossary-related { display: flex; flex-wrap: wrap; gap: .4rem .7rem; margin-top: 1rem; padding-top: .8rem; border-top: 1px solid var(--border); font-size: .75rem; }
.glossary-related span { color: var(--muted); }
.glossary-related a { font-weight: 800; }

.ad-slot {
  min-height: 90px;
  margin: 2.5rem 0;
  padding: .5rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--muted);
  background: var(--surface-soft);
  text-align: center;
}
.ad-label { display: block; margin-bottom: .3rem; font-size: .72rem; letter-spacing: .06em; }

.article-footer { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--border); }
.exercise-answer-link { display:flex; align-items:center; justify-content:space-between; gap:1rem; margin:1.5rem 0 2.5rem; padding:1.1rem 1.25rem; border:1px solid var(--accent); border-radius:14px; background:var(--soft); }
.exercise-answer-link a { color:var(--accent-strong); font-weight:800; }
.review-note {
  padding: 1rem;
  border-radius: 10px;
  border-left: 4px solid var(--gold);
  color: var(--muted);
  background: var(--gold-soft);
  font-size: .9rem;
}
.lesson-navigation {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .75rem;
  margin-top: 1.5rem;
}
.lesson-navigation a {
  display: block;
  padding: .9rem;
  border: 1px solid #b7d8d2;
  border-radius: 10px;
  color: var(--brand-dark);
  background: var(--previous-background);
  font-weight: 750;
  text-decoration: none;
  transition: transform .18s ease, box-shadow .18s ease;
}
.lesson-navigation a:hover { transform: translateY(-2px); box-shadow: 0 8px 18px rgb(16 47 70 / 10%); }
.lesson-navigation a:last-child { border-color: #d6c7ed; color: var(--violet); background: var(--next-background); text-align: right; }

.site-footer {
  padding: 2rem 0;
  border-top: 1px solid var(--border);
  color: var(--muted);
  background: var(--surface);
  font-size: .88rem;
}
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem; }
.footer-links { gap: .8rem; }
.privacy-settings-link { padding: 0; border: 0; color: inherit; background: none; text-decoration: underline; cursor: pointer; font: inherit; }

@media (max-width: 640px) {
  body { font-size: 16px; word-break: normal; }
  .header-inner { align-items: flex-start; flex-direction: column; padding-block: .85rem; }
  .site-nav { gap: .65rem 1rem; }
  .theme-picker { width: 100%; }
  .page-shell { width: 100%; margin-top: 0; }
  .breadcrumbs { padding: .8rem 1rem 0; }
  .article-card { border-right: 0; border-left: 0; border-radius: 0; }
  .article-header { padding-top: 2.6rem; }
  .table-of-contents { padding-left: 1.2rem; }
  .table-of-contents::before { display: none; }
  .table-of-contents :is(ol, ul) { grid-template-columns: 1fr; }
  .article-body h2 { margin-top: 3rem; padding-inline: .85rem; }
  .glossary-heading { grid-template-columns: 1fr; gap: .5rem; }
  .glossary-grid, .glossary-index-grid { grid-template-columns: 1fr; }
  .flow-horizontal { align-items: stretch; flex-direction: column; gap: 2rem; }
  .flow-horizontal .flow-step { justify-content: flex-start; text-align: left; }
  .flow-horizontal .flow-step:not(:first-child)::before {
    top: -1.72rem;
    left: 50%;
    content: "↓";
    transform: translateX(-50%);
  }
  .lesson-navigation { grid-template-columns: 1fr; }
  .lesson-navigation a:last-child { text-align: left; }
}

@media print {
  .site-header, .site-footer, .ad-slot, .lesson-navigation, .table-of-contents { display: none; }
  body, .article-card { color: #000; background: #fff; }
  .article-card { max-width: none; padding: 0; border: 0; box-shadow: none; }
}