:root {
  --ink: #0b1b3c;
  --ink-soft: #39465e;
  --teal: #087b83;
  --coral: #ef5a45;
  --line: #d9e0e8;
  --line-strong: #c4cfda;
  --cool: #f5f8fa;
  --white: #ffffff;
  --volume-accent: var(--teal);
  --display: "Iowan Old Style", "Palatino Linotype", Palatino, Baskerville, Georgia, serif;
  --ui: Inter, Aptos, "Segoe UI", Helvetica, Arial, sans-serif;
  --reading: Charter, "Bitstream Charter", Georgia, "Times New Roman", serif;
  color-scheme: light;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; }

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 12px;
  left: 12px;
  padding: 10px 14px;
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  font: 700 14px/1 var(--ui);
  transform: translateY(-150%);
}

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

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Series library */
.series-index { font-family: var(--ui); }

.site-header {
  min-height: 82px;
  padding: 14px clamp(24px, 4vw, 68px);
  display: flex;
  align-items: center;
  gap: 26px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, .97);
  position: sticky;
  top: 0;
  z-index: 50;
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--ink);
  text-decoration: none;
  font: 600 clamp(23px, 2vw, 31px)/1 var(--display);
}

.site-brand img {
  width: 64px;
  height: 50px;
  object-fit: contain;
}

.site-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: clamp(14px, 1.7vw, 29px);
}

.site-nav a,
.language-link {
  position: relative;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  font: 600 clamp(12px, 1vw, 14px)/1.3 var(--ui);
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -14px;
  height: 2px;
  background: var(--coral);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .18s ease;
}

.site-nav a:hover::after,
.site-nav a:focus-visible::after,
.site-nav a[aria-current="page"]::after { transform: scaleX(1); }

.language-link {
  padding-left: 22px;
  border-left: 1px solid var(--line-strong);
}

.nav-toggle { display: none; }

.series-library {
  max-width: 1500px;
  margin: 0 auto;
  padding: clamp(48px, 5vw, 72px) clamp(24px, 5vw, 78px) 96px;
}

.series-intro {
  display: block;
  padding-bottom: 32px;
}

.series-intro h1 {
  max-width: none;
  margin: 0 0 16px;
  font: 500 clamp(48px, 5.2vw, 76px)/.98 var(--display);
  letter-spacing: -.035em;
}

.series-intro > div:first-child > p {
  max-width: 760px;
  margin: 0;
  color: var(--ink-soft);
  font: 500 clamp(18px, 1.7vw, 24px)/1.45 var(--ui);
}

.series-tools {
  max-width: 790px;
  margin-top: 30px;
  display: grid;
  grid-template-columns: auto minmax(320px, 500px);
  align-items: center;
  column-gap: 36px;
  gap: 18px;
}

.library-count {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--teal);
  font-size: 17px;
}

.library-count svg,
.series-search svg,
.volume-arrow svg {
  width: 24px;
  height: 24px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.series-search {
  min-height: 58px;
  display: flex;
  align-items: center;
  gap: 13px;
  padding: 0 18px;
  border: 1px solid var(--line-strong);
  border-radius: 9px;
  background: var(--white);
  transition: border-color .18s ease, box-shadow .18s ease;
}

.series-search:focus-within {
  border-color: var(--teal);
  box-shadow: 0 0 0 3px rgba(8, 123, 131, .13);
}

.series-search svg { flex: 0 0 auto; color: var(--ink); }

.series-search input {
  width: 100%;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font: 500 16px/1.3 var(--ui);
}

.series-search input::placeholder { color: #727d8e; opacity: 1; }

.volume-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  grid-template-rows: repeat(5, auto);
  grid-auto-flow: column;
  column-gap: clamp(52px, 7vw, 112px);
}

.volume-row {
  --accent: var(--teal);
  min-height: 156px;
  display: grid;
  grid-template-columns: 82px 2px minmax(0, 1fr) 42px;
  gap: 24px;
  align-items: center;
  border-bottom: 1px solid var(--line);
  transition: background .18s ease;
}

.volume-row:hover { background: linear-gradient(90deg, transparent, color-mix(in srgb, var(--accent) 4%, white)); }
.volume-row[hidden] { display: none; }
.volume-1 { --accent: #087b83; }
.volume-2 { --accent: #2157b3; }
.volume-3 { --accent: #28743a; }
.volume-4 { --accent: #7040a0; }
.volume-5 { --accent: #ef5a45; }
.volume-6 { --accent: #354bc0; }
.volume-7 { --accent: #c66a00; }
.volume-8 { --accent: #b51235; }
.volume-9 { --accent: #6b3eb6; }

.volume-number {
  color: var(--accent);
  font: 500 62px/1 var(--display);
  letter-spacing: -.04em;
  font-variant-numeric: tabular-nums;
}

.volume-rule {
  width: 2px;
  height: 86px;
  background: var(--accent);
}

.volume-row h2 { margin: 0; }

.volume-row h2 a {
  color: var(--ink);
  text-decoration: none;
  font: 500 clamp(23px, 2.05vw, 31px)/1.14 var(--display);
  letter-spacing: -.012em;
}

.volume-row h2 a:hover,
.volume-row h2 a:focus-visible { color: var(--accent); }

.volume-row p {
  margin: 8px 0 0;
  color: #697487;
  font: 500 15px/1.4 var(--ui);
}

.volume-arrow {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: var(--accent);
  transition: transform .18s ease, background .18s ease;
}

.volume-arrow:hover,
.volume-arrow:focus-visible {
  background: color-mix(in srgb, var(--accent) 9%, white);
  transform: translateX(3px);
}

.no-results {
  grid-column: 1 / -1;
  padding: 64px 0;
  color: var(--ink-soft);
  font: 500 18px/1.5 var(--ui);
}

.series-footer {
  display: flex;
  justify-content: space-between;
  gap: 48px;
  padding: 34px clamp(24px, 5vw, 78px);
  border-top: 1px solid var(--line);
  color: #5c687a;
  font: 500 13px/1.5 var(--ui);
}

.series-footer p { max-width: 620px; margin: 0; }

/* Shared book reader refinements */
body:not(.series-index) {
  font-family: var(--reading);
  font-size: 17px;
  line-height: 1.7;
  color: #162139;
  background: #fff;
}

body:not(.series-index) .app {
  grid-template-columns: 292px minmax(0, 1fr);
  background: #fff;
}

body:not(.series-index) .sidebar {
  z-index: 40;
  padding: 0;
  background: #f8fafb;
  color: var(--ink);
  border-right: 1px solid var(--line);
  border-top: 0;
  box-shadow: none;
}

body:not(.series-index) .sidebar-brand {
  min-height: 124px;
  padding: 18px 20px 15px;
  border-bottom: 1px solid var(--line);
}

.reader-brand-row { display: flex; align-items: center; gap: 10px; }
.reader-brand-row img { width: 58px; height: 45px; object-fit: contain; }

body:not(.series-index) .sidebar-brand .mark {
  color: var(--ink);
  font: 600 19px/1 var(--display);
  letter-spacing: -.01em;
  text-transform: none;
}

body:not(.series-index) .sidebar-brand .title {
  margin-top: 5px;
  color: var(--volume-accent);
  font: 700 13px/1.25 var(--ui);
}

.all-volumes-link {
  display: inline-block;
  margin: 11px 0 0 52px;
  color: #5e6b7c;
  text-decoration: none;
  font: 600 12px/1.25 var(--ui);
}

.all-volumes-link:hover,
.all-volumes-link:focus-visible { color: var(--volume-accent); text-decoration: underline; }

body:not(.series-index) .sidebar-search {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
}

body:not(.series-index) .sidebar-search input {
  padding: 10px 12px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font: 500 13px/1.35 var(--ui);
}

body:not(.series-index) .sidebar-search input::placeholder { color: #758093; }

body:not(.series-index) .sidebar-search input:focus {
  outline: 3px solid color-mix(in srgb, var(--volume-accent) 18%, white);
  border-color: var(--volume-accent);
  background: #fff;
}

body:not(.series-index) .book-nav { padding: 8px 0 48px; }
body:not(.series-index) .book-group { border-bottom: 1px solid var(--line); }

body:not(.series-index) .book-head {
  min-height: 56px;
  gap: 10px;
  padding: 11px 16px;
  color: var(--ink);
}

body:not(.series-index) .book-head:hover { background: #eef3f5; }

body:not(.series-index) .book-head .num {
  background: var(--volume-accent);
  border-radius: 50%;
  font: 700 11px/24px var(--ui);
}

body:not(.series-index) .book-head .name {
  color: var(--ink);
  font: 700 12px/1.3 var(--ui);
}

body:not(.series-index) .book-head .chev { color: #758093; }

body:not(.series-index) .chapter-item {
  gap: 8px;
  min-height: 42px;
  padding: 7px 14px 7px 42px;
  color: #344158;
  font: 500 11.5px/1.32 var(--ui);
}

body:not(.series-index) .chapter-item:hover { background: #eef3f5; color: var(--ink); }
body:not(.series-index) .chapter-item.built { color: #344158; }

body:not(.series-index) .chapter-item.active {
  position: relative;
  background: color-mix(in srgb, var(--volume-accent) 8%, white);
  color: var(--volume-accent);
  font-weight: 700;
}

body:not(.series-index) .chapter-item.active::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--volume-accent);
}

body:not(.series-index) .chapter-item .cnum { color: #8993a2; }

body:not(.series-index) .chapter-item .badge,
body:not(.series-index) .book-card .pill { display: none; }

body:not(.series-index) .chapter-toc {
  margin: 0;
  padding: 0 0 10px;
  background: #fff;
  border-left: 3px solid var(--volume-accent);
}

body:not(.series-index) .chapter-toc-head {
  padding: 11px 16px 8px 20px;
  color: var(--ink-soft);
  font: 800 10px/1.2 var(--ui);
  letter-spacing: .08em;
  text-transform: uppercase;
}

body:not(.series-index) .chapter-toc-list a {
  padding: 5px 14px 5px 20px;
  color: #5a6678;
  font: 500 11px/1.3 var(--ui);
}

body:not(.series-index) .chapter-toc-list a:hover,
body:not(.series-index) .chapter-toc-list a.active {
  background: #f2f6f7;
  color: var(--volume-accent);
  text-decoration: none;
}

body:not(.series-index) .main,
body:not(.series-index) .reader { background: #fff; }

body:not(.series-index) .reader {
  width: 100%;
  max-width: none;
  padding: 0 0 120px;
}

body:not(.series-index) .module-doc {
  max-width: 1120px;
  margin: 0 auto;
}

body:not(.series-index) .module-topbar {
  z-index: 35;
  min-height: 62px;
  padding: 0 clamp(26px, 4vw, 56px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, .96);
  backdrop-filter: blur(12px);
  font-family: var(--ui);
}

.reader-menu-btn { display: none; }

.topbar-all-volumes,
body:not(.series-index) .module-topbar .back,
body:not(.series-index) .module-topbar .crumb {
  color: #596579;
  text-decoration: none;
  font: 600 12px/1.2 var(--ui);
}

.topbar-all-volumes {
  margin-right: 14px;
  padding-right: 14px;
  border-right: 1px solid var(--line);
}

.topbar-all-volumes:hover,
.topbar-all-volumes:focus-visible,
body:not(.series-index) .module-topbar .back:hover { color: var(--volume-accent); text-decoration: none; }

body:not(.series-index) .module-topbar button {
  padding: 8px 13px;
  border: 1px solid var(--line-strong);
  border-radius: 7px;
  background: #fff;
  color: var(--ink);
  font: 700 12px/1 var(--ui);
}

body:not(.series-index) .module-topbar button:hover,
body:not(.series-index) .module-topbar button:focus-visible {
  border-color: var(--volume-accent);
  color: var(--volume-accent);
  outline: none;
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--volume-accent) 13%, white);
}

body:not(.series-index) .module-header {
  position: relative;
  padding: 68px clamp(34px, 7vw, 100px) 54px clamp(168px, 16vw, 220px);
  border-bottom: 1px solid var(--line);
  text-align: left;
  background: #fff;
}

body:not(.series-index) .module-header::before {
  content: attr(data-chapter);
  position: absolute;
  left: clamp(36px, 6vw, 86px);
  top: 69px;
  color: var(--volume-accent);
  font: 500 64px/1 var(--display);
}

body:not(.series-index) .module-header::after {
  content: "";
  position: absolute;
  top: 68px;
  bottom: 54px;
  left: clamp(135px, 13vw, 178px);
  width: 1px;
  background: var(--line-strong);
}

body:not(.series-index) .module-header .series-label {
  margin-left: 0;
  color: var(--volume-accent);
  font: 700 13px/1.3 var(--ui);
  letter-spacing: 0;
  text-transform: none;
}

body:not(.series-index) .module-header .chapter-title {
  max-width: 900px;
  margin: 12px 0 22px;
  color: var(--ink);
  font: 500 clamp(43px, 5.7vw, 75px)/.99 var(--display);
  letter-spacing: -.035em;
  text-transform: none;
}

body:not(.series-index) .module-header .prepared,
body:not(.series-index) .module-header .standards {
  margin-top: 6px;
  color: #657185;
  font: 500 12px/1.45 var(--ui);
  letter-spacing: 0;
}

body:not(.series-index) .module-body {
  max-width: 960px;
  margin: 0 auto;
  padding: 56px clamp(26px, 4.5vw, 64px) 110px;
}

body:not(.series-index) .module-body > section { scroll-margin-top: 82px; }

body:not(.series-index) .section-banner {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin: 0 0 32px;
  padding: 34px 0 16px;
  border-top: 1px solid var(--line);
  border-radius: 0;
  background: transparent;
  color: var(--ink);
  font: 500 clamp(29px, 3.5vw, 43px)/1.1 var(--display);
  letter-spacing: -.025em;
  text-transform: none;
}

body:not(.series-index) .module-body > section:first-child .section-banner {
  padding-top: 0;
  border-top: 0;
}

body:not(.series-index) .section-banner .sec-num {
  color: var(--volume-accent);
  opacity: 1;
  font: 600 14px/1 var(--ui);
  letter-spacing: .06em;
}

body:not(.series-index) .module-body h3,
body:not(.series-index) .module-body .subheading {
  margin: 34px 0 12px;
  color: var(--ink);
  font: 600 24px/1.2 var(--display);
  letter-spacing: -.012em;
}

body:not(.series-index) .body,
body:not(.series-index) .module-body > section > p,
body:not(.series-index) .callout p,
body:not(.series-index) .callout li {
  font-family: var(--reading);
  font-size: 17px;
  line-height: 1.68;
}

body:not(.series-index) .module-body > section > p {
  max-width: 790px;
  margin: 0 0 18px;
}

body:not(.series-index) .section-rule {
  margin: 58px 0 0;
  border-color: var(--line);
}

body:not(.series-index) .callout {
  margin: 24px 0;
  padding: 22px 24px;
  border: 1px solid color-mix(in srgb, currentColor 18%, white);
  border-left-width: 4px;
  border-radius: 8px;
  box-shadow: none;
}

body:not(.series-index) .callout .co-label {
  margin-bottom: 9px;
  font: 800 11px/1.2 var(--ui);
  letter-spacing: .1em;
}

body:not(.series-index) .callout .co-title {
  margin-bottom: 9px;
  color: var(--ink);
  font: 750 15px/1.35 var(--ui);
}

body:not(.series-index) .co-mechanism { background: #f1f6ff; border-color: #2b67bd; }
body:not(.series-index) .co-mechanism .co-label { color: #2159a6; }
body:not(.series-index) .co-clinical { background: #f1f8f3; border-color: #2d7f49; }
body:not(.series-index) .co-clinical .co-label { color: #21673a; }
body:not(.series-index) .co-pearl { background: #fff9e9; border-color: #b97900; }
body:not(.series-index) .co-pearl .co-label { color: #966100; }
body:not(.series-index) .co-trap { background: #fff3f2; border-color: #bd3f3a; }
body:not(.series-index) .co-trap .co-label { color: #9e302c; }
body:not(.series-index) .co-case { background: #f8f3fb; border-color: #7a4695; }
body:not(.series-index) .co-case .co-label { color: #66377f; }
body:not(.series-index) .co-formula { background: #fff7ee; border-color: #b85f20; }
body:not(.series-index) .co-formula .co-label { color: #944915; }
body:not(.series-index) .co-board { background: #fff5ed; border-color: #c45116; }
body:not(.series-index) .co-board .co-label { color: #a33e0b; }
body:not(.series-index) .co-mcq { background: #fff9e9; border-color: #a86d00; }
body:not(.series-index) .co-mcq .co-label { color: #855700; }
body:not(.series-index) .co-memory { background: #fff7ed; border-color: #9f6427; }
body:not(.series-index) .co-memory .co-label { color: #7c4c1c; }
body:not(.series-index) .co-review { background: #f3f5f7; border-color: #687588; }
body:not(.series-index) .co-review .co-label { color: #4f5b6c; }

body:not(.series-index) .mech-field {
  grid-template-columns: minmax(150px, 190px) 1fr;
  gap: 18px;
  padding: 10px 0;
  border-top-color: rgba(43, 103, 189, .18);
}

body:not(.series-index) .mech-field .mf-key {
  color: #2159a6;
  font: 800 11px/1.4 var(--ui);
}

body:not(.series-index) .mech-field .mf-val { font-size: 16px; line-height: 1.58; }

body:not(.series-index) .tbl-wrap,
body:not(.series-index) .diagram {
  margin: 28px 0;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: #fff;
  box-shadow: none;
}

body:not(.series-index) .tbl-caption,
body:not(.series-index) .diagram .dg-title {
  padding: 13px 16px;
  border-bottom: 1px solid var(--line);
  background: #f7fafb;
  color: var(--ink);
  font: 800 13px/1.35 var(--ui);
}

body:not(.series-index) table.data {
  font-family: var(--ui);
  font-size: 13px;
  line-height: 1.5;
}

body:not(.series-index) table.data thead th {
  background: var(--ink);
  color: #fff;
  font: 750 12px/1.35 var(--ui);
}

body:not(.series-index) table.data tbody tr:nth-child(even) { background: #f5f8fa; }
body:not(.series-index) table.data tbody tr:nth-child(odd) { background: #fff; }

body:not(.series-index) .diagram .dg-body,
body:not(.series-index) .mono-block {
  color: #26364e;
  font-size: 13px;
  line-height: 1.55;
  background: #fbfcfd;
}

body:not(.series-index) .mcq .opts li {
  border-color: #e2d6aa;
  border-radius: 6px;
  background: rgba(255, 255, 255, .72);
  font: 500 14px/1.45 var(--ui);
}

body:not(.series-index) .flashcard {
  min-height: 205px;
  border-radius: 8px;
}

body:not(.series-index) .fc-face {
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  box-shadow: none;
}

body:not(.series-index) .fc-q { color: var(--ink); font: 700 15px/1.45 var(--ui); }
body:not(.series-index) .rapid { border-color: #687588; border-radius: 8px; }
body:not(.series-index) .rapid .rr-head { background: #4f5b6c; font-family: var(--ui); }

body:not(.series-index) .hero {
  padding: 68px clamp(34px, 7vw, 100px) 56px;
  background: #fff;
  color: var(--ink);
  text-align: left;
  border-bottom: 1px solid var(--line);
}

body:not(.series-index) .hero .series { color: var(--volume-accent); font: 700 13px/1.3 var(--ui); letter-spacing: 0; text-transform: none; }
body:not(.series-index) .hero h1 { max-width: 880px; margin: 14px 0; color: var(--ink); font: 500 clamp(46px, 6vw, 76px)/1 var(--display); letter-spacing: -.035em; text-transform: none; }
body:not(.series-index) .hero p { max-width: 760px; margin: 0; color: var(--ink-soft); font: 500 18px/1.55 var(--ui); }
body:not(.series-index) .hero .exam { margin-top: 22px; color: #657185; font: 600 12px/1.5 var(--ui); letter-spacing: 0; }
body:not(.series-index) .hero .credit { margin: 28px 0 0; padding-top: 20px; border-top-color: var(--line); color: #657185; }
body:not(.series-index) .hero .credit-site { color: var(--volume-accent); }

body:not(.series-index) .library { padding: 42px clamp(34px, 7vw, 100px) 90px; }
body:not(.series-index) .lib-intro { border-bottom-color: var(--line); color: var(--ink-soft); font-family: var(--ui); }
body:not(.series-index) .book-cards { grid-template-columns: 1fr; }
body:not(.series-index) .book-card { max-width: 760px; border-color: var(--line-strong); border-radius: 8px; box-shadow: none; }
body:not(.series-index) .book-card .bc-head { background: var(--volume-accent); }
body:not(.series-index) .book-card .bc-body { font-family: var(--ui); }

:focus-visible { outline: 3px solid rgba(8, 123, 131, .3); outline-offset: 3px; }

@media (max-width: 1180px) {
  .site-header { flex-wrap: wrap; }
  .site-nav { order: 3; width: 100%; justify-content: space-between; padding-top: 9px; border-top: 1px solid var(--line); }
  .site-nav a::after { bottom: -9px; }
  .series-tools { max-width: 580px; grid-template-columns: auto 1fr; align-items: center; }
}

@media (max-width: 900px) {
  .site-header { min-height: 70px; flex-wrap: nowrap; }
  .site-brand img { width: 54px; height: 42px; }
  .site-nav {
    position: absolute;
    inset: 100% 0 auto;
    display: none;
    padding: 16px 24px 24px;
    background: #fff;
    box-shadow: 0 14px 26px rgba(17, 34, 57, .1);
  }
  .site-nav.is-open { display: grid; gap: 0; }
  .site-nav a { padding: 12px 0; border-bottom: 1px solid var(--line); }
  .site-nav a::after { display: none; }
  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
    padding: 9px 12px;
    border: 1px solid var(--line-strong);
    border-radius: 7px;
    background: #fff;
    color: var(--ink);
    font: 700 13px/1 var(--ui);
  }
  .volume-list { display: block; }
  .volume-row { min-height: 138px; }
  .series-footer { display: grid; }
}

@media (max-width: 980px) {
  body:not(.series-index) .app { display: block; }
  body:not(.series-index) .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(84vw, 320px);
    height: 100vh;
    transform: translateX(-105%);
    transition: transform .22s ease;
    box-shadow: 12px 0 34px rgba(11, 27, 60, .14);
  }
  body.reader-nav-open .sidebar { transform: translateX(0); }
  .reader-menu-btn { display: inline-flex; }
  body:not(.series-index) .module-topbar { position: sticky; top: 0; padding-inline: 18px; }
  body:not(.series-index) .module-topbar .crumb { display: none; }
  body:not(.series-index) .module-header { padding: 46px 28px 40px; }
  body:not(.series-index) .module-header::before,
  body:not(.series-index) .module-header::after { display: none; }
  body:not(.series-index) .module-body { padding: 42px 24px 90px; }
}

@media (max-width: 640px) {
  .site-header { padding-inline: 18px; gap: 14px; }
  .site-brand span { font-size: 23px; }
  .language-link { padding-left: 14px; font-size: 12px; }
  .series-library { padding: 50px 18px 70px; }
  .series-intro { gap: 32px; padding-bottom: 30px; }
  .series-intro h1 { font-size: clamp(45px, 14vw, 64px); }
  .series-tools { grid-template-columns: 1fr; }
  .volume-row { grid-template-columns: 54px 2px minmax(0, 1fr) 34px; gap: 14px; min-height: 126px; }
  .volume-number { font-size: 42px; }
  .volume-rule { height: 72px; }
  .volume-row h2 a { font-size: 22px; }
  .volume-arrow { width: 34px; height: 34px; }
  .volume-arrow svg { width: 20px; height: 20px; }
  .series-footer { padding-inline: 18px; }

  body:not(.series-index) .module-topbar .back,
  .topbar-all-volumes { display: none; }
  body:not(.series-index) .module-header .chapter-title { font-size: clamp(40px, 13vw, 58px); }
  body:not(.series-index) .module-body { padding-inline: 18px; }
  body:not(.series-index) .body,
  body:not(.series-index) .module-body > section > p,
  body:not(.series-index) .callout p,
  body:not(.series-index) .callout li { font-size: 16px; }
  body:not(.series-index) .section-banner { font-size: 30px; }
  body:not(.series-index) .mech-field { grid-template-columns: 1fr; gap: 4px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; }
}

@media print {
  .site-header,
  .series-footer,
  body:not(.series-index) .sidebar,
  body:not(.series-index) .module-topbar { display: none !important; }
  body:not(.series-index) .app { display: block; }
  body:not(.series-index) .module-doc { max-width: none; }
  body:not(.series-index) .module-header { padding: 0 0 18mm; }
  body:not(.series-index) .module-body { max-width: none; padding: 0; }
  body:not(.series-index) .callout,
  body:not(.series-index) .tbl-wrap,
  body:not(.series-index) .diagram { break-inside: avoid; }
}