/* Silver-paper chapter entrances. Every selector stays inside the chapter gateway. */
.chapter-gateway {
  --chapter-gateway-ink: #262b2d;
  --chapter-gateway-muted: #676b6d;
  --chapter-gateway-rule: #d5d6d5;
  --chapter-gateway-gold: #8b7250;
  --chapter-gateway-paper: #f5f5f2;
  width: min(1240px, 100%);
  margin: 0 auto;
  padding: 36px 48px 80px;
  color: var(--chapter-gateway-ink);
  font-family: "Avenir Next", "PingFang SC", "Microsoft YaHei", sans-serif;
  overflow-wrap: anywhere;
}
.chapter-gateway *, .chapter-gateway *::before, .chapter-gateway *::after { box-sizing: border-box; }
.chapter-gateway a { color: inherit; text-decoration: none; }
.chapter-gateway a:focus-visible { outline: 2px solid var(--chapter-gateway-gold); outline-offset: 6px; }
.chapter-gateway ::selection { background: #e2d6c3; }
.chapter-gateway-visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.chapter-gateway-breadcrumb { display: flex; align-items: center; gap: 18px; font-size: 12px; color: var(--chapter-gateway-muted); }
.chapter-gateway-breadcrumb a { display: inline-flex; align-items: center; gap: 10px; min-height: 36px; }
.chapter-gateway-breadcrumb a:hover { color: var(--chapter-gateway-ink); }
.chapter-gateway-breadcrumb > span:nth-child(2) { color: #a8aaa8; }
.chapter-gateway-hero { display: grid; grid-template-columns: minmax(0, 1.19fr) minmax(0, .91fr); gap: 76px; align-items: center; padding: 36px 0 52px; }
.chapter-gateway-hero--text { grid-template-columns: 1fr; max-width: 800px; }
.chapter-gateway-introduction { min-width: 0; padding-bottom: 12px; }
.chapter-gateway-heading-mark { display: flex; align-items: flex-end; gap: 25px; margin-bottom: 27px; }
.chapter-gateway-number { font-size: clamp(66px, 7.3vw, 108px); font-weight: 400; line-height: .88; letter-spacing: -.075em; color: #b1b3b2; font-variant-numeric: tabular-nums; }
.chapter-gateway-edition { display: flex; flex-direction: column; gap: 5px; padding-bottom: 4px; color: var(--chapter-gateway-gold); font-size: 11px; letter-spacing: .08em; }
.chapter-gateway-edition > span { color: var(--chapter-gateway-muted); font-size: 10px; letter-spacing: .14em; font-variant-numeric: tabular-nums; }
.chapter-gateway h1 { margin: 0; max-width: 680px; font-size: clamp(31px, 3vw, 43px); font-weight: 500; line-height: 1.4; letter-spacing: -.035em; text-wrap: balance; color: var(--chapter-gateway-ink); }
.chapter-gateway-intro { max-width: 520px; margin: 23px 0 27px; font-size: 14px; line-height: 1.95; color: var(--chapter-gateway-muted); text-wrap: pretty; }
.chapter-gateway-start { display: inline-flex; align-items: center; justify-content: space-between; gap: 38px; min-height: 49px; padding: 12px 20px; border: 1px solid #303637; border-radius: 2px; background: #303637; color: #fff !important; font-size: 13px; transition: background .18s, transform .18s, box-shadow .18s; }
.chapter-gateway-start:hover { background: #474744; transform: translateY(-2px); box-shadow: 0 5px 12px #20232414; }
.chapter-gateway-start > span:last-child { font-size: 20px; line-height: 1; }
.chapter-gateway-archive { position: relative; margin: 0; min-width: 0; width: 100%; max-width: 430px; justify-self: end; padding: 21px 25px 0; border: 1px solid #dddedc; border-radius: 3px; background: linear-gradient(142deg, #e4e5e3, #eeefed 48%, #dedfdd); }
.chapter-gateway-archive-top { position: relative; z-index: 2; display: flex; justify-content: space-between; gap: 15px; color: #5b6060; font-size: 10px; letter-spacing: .04em; }
.chapter-gateway-archive-top time { font-size: 12px; letter-spacing: .06em; }
.chapter-gateway-archive-link { display: block; position: relative; height: 326px; margin: 17px 17px 22px; isolation: isolate; }
.chapter-gateway-archive-back { position: absolute; inset: 18px 12px 0; background: #ede8dd; border: 1px solid #d0c7b9; transform: rotate(6deg); box-shadow: 0 10px 24px #23282914; }
.chapter-gateway-archive-sheet { display: flex; position: absolute; inset: 7px 6px 0; flex-direction: column; background: #fdfdfb; border: 1px solid #d0d0ca; box-shadow: 0 15px 25px #33393624, 0 2px 4px #3339360d; transform: rotate(-5deg); transform-origin: 50% 85%; transition: transform .28s ease, box-shadow .28s ease; overflow: hidden; }
.chapter-gateway-archive-sheet img { display: block; width: 100%; height: 100%; max-width: none; object-fit: cover; object-position: top; }
.chapter-gateway-archive-link:hover .chapter-gateway-archive-sheet, .chapter-gateway-archive-link:focus-visible .chapter-gateway-archive-sheet { transform: rotate(-1.5deg) translateY(-3px); box-shadow: 0 20px 30px #3339362b; }
.chapter-gateway-archive-open { position: absolute; z-index: 2; right: -12px; bottom: -7px; display: grid; place-items: center; width: 36px; height: 36px; border: 1px solid #b9b3a8; border-radius: 50%; background: #f2ede3; color: #65563f; font-size: 19px; }
.chapter-gateway-archive figcaption { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; border-top: 1px solid #c9ccca; padding: 15px 0 16px; color: #656967; font-size: 10px; line-height: 1.6; }
.chapter-gateway-archive figcaption > span:first-child { max-width: 76%; }
.chapter-gateway-archive figcaption > span:last-child { flex-shrink: 0; color: #6d5d45; }
.chapter-gateway-archive--type .chapter-gateway-archive-sheet { padding: 26px 25px 21px; }
.chapter-gateway-archive-category { color: #716c62; font-size: 11px; }
.chapter-gateway-archive-word { margin: auto 0 20px; font-size: clamp(24px, 2.9vw, 41px); line-height: 1.2; letter-spacing: -.055em; font-weight: 500; text-wrap: balance; }
.chapter-gateway-archive-rule { display: block; height: 1px; width: 45px; margin-bottom: 14px; background: #b19e81; }
.chapter-gateway-archive-people { color: #6b6b66; font-size: 10px; }
.chapter-gateway-archive-date { margin-top: 7px; color: #8a8173; font-size: 11px; letter-spacing: .08em; }
.chapter-gateway-reading-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 20px 40px; border-block: 1px solid var(--chapter-gateway-rule); padding: 23px 0; color: var(--chapter-gateway-muted); font-size: 11px; }
.chapter-gateway-reading-meta strong { color: var(--chapter-gateway-ink); font-size: 13px; font-weight: 500; margin-right: 5px; }
.chapter-gateway-reading-progress { display: flex; align-items: center; gap: 22px; margin-left: auto; }
.chapter-gateway-reading-progress strong { margin: 0 0 0 6px; font-variant-numeric: tabular-nums; }
.chapter-gateway-reading-progress progress { display: block; width: 100px; height: 3px; border: 0; border-radius: 0; background: #dbddda; accent-color: var(--chapter-gateway-gold); appearance: none; }
.chapter-gateway-reading-progress progress::-webkit-progress-bar { background: #dbddda; }
.chapter-gateway-reading-progress progress::-webkit-progress-value { background: var(--chapter-gateway-gold); }
.chapter-gateway-reading-progress progress::-moz-progress-bar { background: var(--chapter-gateway-gold); }
.chapter-gateway-curriculum { padding: 61px 0 0; }
.chapter-gateway-section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; margin-bottom: 26px; }
.chapter-gateway-section-caption { margin: 0 0 9px; color: var(--chapter-gateway-muted); font-size: 11px; }
.chapter-gateway h2 { margin: 0; font-size: 26px; font-weight: 500; line-height: 1.35; letter-spacing: -.025em; color: var(--chapter-gateway-ink); }
.chapter-gateway-course-count { color: #777b79; font-size: 9px; letter-spacing: .12em; padding-bottom: 3px; white-space: nowrap; }
.chapter-gateway-course-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid #b9bdb8; }
.chapter-gateway-course { margin: 0; border-bottom: 1px solid var(--chapter-gateway-rule); }
.chapter-gateway-course-link { display: grid; position: relative; grid-template-columns: 42px minmax(0, 1fr) 84px 24px; align-items: center; gap: 25px; min-height: 124px; padding: 24px 7px 25px 0; transition: background .18s; }
.chapter-gateway-course-link::before { content: ""; position: absolute; left: -16px; top: 24px; bottom: 24px; width: 2px; background: var(--chapter-gateway-gold); opacity: 0; transform: scaleY(.4); transition: opacity .18s, transform .18s; }
.chapter-gateway-course-link:hover { background: #e8e9e54f; }
.chapter-gateway-course-link:hover::before, .chapter-gateway-course-link:focus-visible::before { opacity: 1; transform: scaleY(1); }
.chapter-gateway-course-number { align-self: start; padding-top: 3px; color: #929690; font-size: 23px; font-weight: 400; letter-spacing: -.045em; font-variant-numeric: tabular-nums; }
.chapter-gateway-course-content { min-width: 0; }
.chapter-gateway-course-topline { display: flex; flex-wrap: wrap; gap: 4px 15px; margin-bottom: 9px; color: var(--chapter-gateway-muted); font-size: 10px; line-height: 1.6; }
.chapter-gateway-course-topline > span:first-child { color: var(--chapter-gateway-gold); }
.chapter-gateway-course-title { display: block; font-size: 17px; line-height: 1.6; font-weight: 500; text-wrap: pretty; }
.chapter-gateway-course-detail { display: flex; flex-direction: column; align-items: flex-end; gap: 8px; }
.chapter-gateway-course-duration { color: #636862; font-size: 11px; font-variant-numeric: tabular-nums; letter-spacing: .025em; }
.chapter-gateway-course-status { color: #767b74; font-size: 10px; }
.chapter-gateway-course--read .chapter-gateway-course-status { color: #6f5b3d; }
.chapter-gateway-course--read .chapter-gateway-course-status::before { content: ""; display: inline-block; width: 4px; height: 4px; margin: 0 6px 2px 0; border-radius: 50%; background: #8b7250; }
.chapter-gateway-course-arrow { font-size: 23px; color: #8b918a; transition: transform .18s, color .18s; }
.chapter-gateway-course-link:hover .chapter-gateway-course-arrow { color: var(--chapter-gateway-gold); transform: translate(2px, -2px); }
.chapter-gateway-history { padding: 72px 0 0; }
.chapter-gateway-text-link { border-bottom: 1px solid #b9b6ae; padding-bottom: 3px; color: #6c6659 !important; font-size: 11px; white-space: nowrap; }
.chapter-gateway-text-link > span { margin-left: 10px; }
.chapter-gateway-history-list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 1px solid var(--chapter-gateway-rule); }
.chapter-gateway-history-list:has(> :last-child:nth-child(2)) { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.chapter-gateway-history-item { position: relative; padding: 28px 27px 4px 0; }
.chapter-gateway-history-item + .chapter-gateway-history-item { padding-left: 27px; }
.chapter-gateway-history-item + .chapter-gateway-history-item::before { content: ""; position: absolute; left: 0; top: 31px; bottom: 4px; width: 1px; background: var(--chapter-gateway-rule); }
.chapter-gateway-history-item > time { display: block; margin-bottom: 19px; font-size: 38px; line-height: 1.1; letter-spacing: -.055em; color: #9a9f99; font-variant-numeric: tabular-nums; white-space: nowrap; }
.chapter-gateway-history-relation { color: #81725b; font-size: 10px; }
.chapter-gateway-history-item h3 { margin: 9px 0 10px; font-size: 15px; line-height: 1.65; font-weight: 500; }
.chapter-gateway-history-item h3 a { text-decoration-thickness: 1px; text-underline-offset: 4px; }
.chapter-gateway-history-item h3 a:hover { text-decoration-line: underline; }
.chapter-gateway-history-item p { margin: 0 0 15px; color: var(--chapter-gateway-muted); font-size: 12px; line-height: 1.9; }
.chapter-gateway-history-source { display: inline-flex; gap: 13px; align-items: center; min-height: 30px; color: #6c6659 !important; font-size: 10px; }
.chapter-gateway-history-source:hover { text-decoration: underline; text-underline-offset: 4px; }
.chapter-gateway-adjacent { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 55px; margin-top: 74px; border-top: 1px solid #b9bdb8; padding-top: 27px; }
.chapter-gateway-adjacent-link { min-width: 0; display: flex; flex-direction: column; align-items: flex-start; gap: 13px; padding: 5px 0; }
.chapter-gateway-adjacent-link--next { align-items: flex-end; text-align: right; }
.chapter-gateway-adjacent-label { color: var(--chapter-gateway-muted); font-size: 10px; }
.chapter-gateway-adjacent-label > span { margin-left: 13px; }
.chapter-gateway-adjacent-name { display: flex; gap: 15px; font-size: 15px; font-weight: 500; line-height: 1.75; transition: color .18s; }
.chapter-gateway-adjacent-name > span { color: #999e97; font-size: 16px; font-variant-numeric: tabular-nums; }
.chapter-gateway-adjacent-link:hover .chapter-gateway-adjacent-name { color: var(--chapter-gateway-gold); }
@media (max-width: 1024px) {
  .chapter-gateway { padding-inline: 36px; }
  .chapter-gateway-hero { gap: 40px; grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); }
  .chapter-gateway h1 { font-size: 34px; }
  .chapter-gateway-archive { padding: 18px 19px 0; }
  .chapter-gateway-archive-link { height: 300px; margin-inline: 3px; }
  .chapter-gateway-archive--type .chapter-gateway-archive-sheet { padding-inline: 21px; }
  .chapter-gateway-archive-word { font-size: 30px; }
  .chapter-gateway-course-link { gap: 19px; }
  .chapter-gateway-reading-meta { gap: 18px 24px; }
}
@media (max-width: 760px) {
  .chapter-gateway { padding: 21px 24px 55px; }
  .chapter-gateway-hero { grid-template-columns: minmax(0, 1fr); gap: 26px; padding: 29px 0 36px; }
  .chapter-gateway-heading-mark { gap: 22px; margin-bottom: 25px; }
  .chapter-gateway-number { font-size: 79px; }
  .chapter-gateway h1 { font-size: 33px; max-width: 600px; }
  .chapter-gateway-intro { margin-block: 19px 24px; max-width: 620px; }
  .chapter-gateway-archive { justify-self: center; max-width: 440px; padding: 19px 26px 0; }
  .chapter-gateway-archive-link { height: 274px; width: min(235px, 82%); margin: 15px auto 22px; }
  .chapter-gateway-archive-word { font-size: 32px; }
  .chapter-gateway-reading-meta { gap: 15px 25px; padding-block: 19px; }
  .chapter-gateway-reading-progress { margin-left: 0; gap: 15px; }
  .chapter-gateway-reading-progress progress { width: 68px; }
  .chapter-gateway-curriculum { padding-top: 42px; }
  .chapter-gateway-section-heading { gap: 20px; margin-bottom: 22px; }
  .chapter-gateway h2 { font-size: 23px; }
  .chapter-gateway-course-link { grid-template-columns: 30px minmax(0, 1fr) 22px; gap: 3px 15px; padding-block: 22px; min-height: 0; }
  .chapter-gateway-course-number { grid-row: 1 / 3; font-size: 22px; padding-top: 0; }
  .chapter-gateway-course-content { grid-column: 2; }
  .chapter-gateway-course-topline { gap: 3px 10px; margin-bottom: 8px; font-size: 10px; }
  .chapter-gateway-course-title { font-size: 16px; line-height: 1.75; }
  .chapter-gateway-course-detail { grid-column: 2; flex-direction: row; align-items: center; justify-content: flex-start; gap: 18px; margin-top: 7px; }
  .chapter-gateway-course-arrow { grid-column: 3; grid-row: 1 / 3; justify-self: end; font-size: 22px; }
  .chapter-gateway-course-link::before { left: -12px; top: 22px; bottom: 22px; }
  .chapter-gateway-history { padding-top: 49px; }
  .chapter-gateway-history .chapter-gateway-section-heading { align-items: flex-start; flex-direction: column; gap: 15px; }
  .chapter-gateway-history-list, .chapter-gateway-history-list:has(> :last-child:nth-child(2)) { grid-template-columns: minmax(0, 1fr); }
  .chapter-gateway-history-item, .chapter-gateway-history-item + .chapter-gateway-history-item { display: grid; grid-template-columns: 68px minmax(0, 1fr); gap: 17px; padding: 23px 0; border-bottom: 1px solid var(--chapter-gateway-rule); }
  .chapter-gateway-history-item + .chapter-gateway-history-item::before { display: none; }
  .chapter-gateway-history-item > time { font-size: 30px; margin: 3px 0 0; }
  .chapter-gateway-history-item h3 { font-size: 15px; }
  .chapter-gateway-history-item p { margin-bottom: 10px; }
  .chapter-gateway-adjacent { gap: 27px; margin-top: 46px; padding-top: 23px; }
  .chapter-gateway-adjacent-name { flex-direction: column; gap: 4px; font-size: 13px; }
  .chapter-gateway-adjacent-link--next .chapter-gateway-adjacent-name { align-items: flex-end; }
}
@media (max-width: 390px) {
  .chapter-gateway { padding-inline: 20px; }
  .chapter-gateway h1 { font-size: 29px; }
  .chapter-gateway-intro { font-size: 13px; }
  .chapter-gateway-course-link { grid-template-columns: 26px minmax(0, 1fr) 16px; column-gap: 11px; }
  .chapter-gateway-course-title { font-size: 15px; }
  .chapter-gateway-archive { padding-inline: 19px; }
  .chapter-gateway-archive figcaption { gap: 10px; font-size: 9px; }
  .chapter-gateway-history-item { grid-template-columns: 61px minmax(0, 1fr); gap: 13px; }
  .chapter-gateway-history-item > time { font-size: 28px; }
}
@media (prefers-reduced-motion: reduce) {
  .chapter-gateway *, .chapter-gateway *::before { transition: none !important; }
  .chapter-gateway-start:hover, .chapter-gateway-archive-link:hover .chapter-gateway-archive-sheet, .chapter-gateway-archive-link:focus-visible .chapter-gateway-archive-sheet, .chapter-gateway-course-link:hover .chapter-gateway-course-arrow { transform: none; }
}
@media print {
  .chapter-gateway { width: auto; max-width: none; padding: 0; color: #111; }
  .chapter-gateway-hero { display: block; padding: 15px 0; }
  .chapter-gateway-archive, .chapter-gateway-start, .chapter-gateway-breadcrumb, .chapter-gateway-adjacent { display: none; }
  .chapter-gateway h1 { font-size: 26pt; }
  .chapter-gateway-number { font-size: 42pt; }
  .chapter-gateway-curriculum, .chapter-gateway-history { padding-top: 25px; }
  .chapter-gateway-course-link { min-height: 0; padding-block: 15px; }
  .chapter-gateway-course, .chapter-gateway-history-item { break-inside: avoid; }
}

.chapter-gateway-history-item>time small{display:block;font-size:12px;letter-spacing:.015em;line-height:1.5;margin-top:5px;color:#817b71}

.chapter-gateway-topic-cover{align-self:center;margin:0;border:1px solid #c5cdd0;border-radius:6px;overflow:hidden;background:#e6e9e8}
.chapter-gateway-topic-cover img{display:block;width:100%;height:auto;aspect-ratio:1.6;object-fit:cover}
.chapter-gateway-topic-cover figcaption{display:flex;justify-content:space-between;gap:15px;padding:14px 17px;font-size:10px;letter-spacing:.08em;color:#69777a}
@media(max-width:760px){.chapter-gateway-topic-cover img{aspect-ratio:2.4}}