:root {
  --b53-ink: #222724;
  --b53-jade: #205c53;
  --b53-jade-dark: #16473f;
  --b53-berry: #983b56;
  --b53-paper: #f7f9f8;
  --b53-white: #fff;
  --b53-line: #d9e1dd;
  --b53-muted: #56655f;
  --b53-serif: "Songti SC", "STSong", "Noto Serif CJK SC", "PMingLiU", serif;
  --b53-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body { margin: 0; background: var(--b53-paper); color: var(--b53-ink); font: 16px/1.85 var(--b53-sans); letter-spacing: 0; }
img { display: block; max-width: 100%; }
button, summary, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; cursor: pointer; }
a { color: var(--b53-jade); text-underline-offset: 5px; text-decoration-thickness: 1px; }
a:hover { color: var(--b53-berry); }
a:focus-visible, button:focus-visible, summary:focus-visible, [tabindex]:focus-visible { outline: 3px solid var(--b53-berry); outline-offset: 5px; }
p, ul, ol, dl, figure { margin: 0 0 1.25em; }
p, li, figcaption { text-wrap: pretty; }
h1, h2, h3 { margin: 0; font-weight: 650; overflow-wrap: anywhere; }
h1, h2 { font-family: var(--b53-serif); }
button:disabled { opacity: .4; cursor: default; }
[hidden] { display: none !important; }
::selection { background: #f1d970; color: #222724; }
.b53-mark-icon { flex: 0 0 auto; vertical-align: middle; stroke-width: 1.7; }
.b53-route-skip { position: fixed; top: -100px; left: 16px; z-index: 10; background: white; padding: 10px 20px; }
.b53-route-skip:focus { top: 10px; }
.b53-mark-mast { background: white; border-top: 4px solid var(--b53-jade); }
.b53-mark-wrap { max-width: 1220px; margin: auto; min-height: 96px; padding: 18px 40px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.b53-mark-identity { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--b53-ink); }
.b53-mark-identity img { width: 52px; height: 52px; object-fit: contain; }
.b53-mark-name { display: flex; align-items: center; gap: 12px; font-family: var(--b53-serif); font-size: 24px; line-height: 1.4; white-space: nowrap; }
.b53-mark-name span { font: 12px/1.4 var(--b53-sans); border-left: 1px solid var(--b53-line); padding-left: 12px; color: var(--b53-muted); }
.b53-mark-identity small { display: block; margin-top: 3px; font-size: 9px; color: var(--b53-muted); }
.b53-route-primary { display: flex; gap: 28px; }
.b53-route-primary a { text-decoration: none; font-size: 14px; color: var(--b53-muted); padding: 9px 0; position: relative; white-space: nowrap; }
.b53-route-primary a span { margin-right: 7px; font-size: 10px; }
.b53-route-primary a::after { content: ''; position: absolute; left: 0; right: 0; bottom: 0; height: 2px; background: var(--b53-jade); transform: scaleX(0); transform-origin: left; transition: transform .2s ease; }
.b53-route-primary a[aria-current], .b53-route-primary a:hover { color: var(--b53-jade); }
.b53-route-primary a[aria-current]::after, .b53-route-primary a:hover::after { transform: scaleX(1); }
.b53-scene-opening { position: relative; isolation: isolate; min-height: 458px; display: grid; align-items: center; color: white; background: #20352d; overflow: hidden; }
.b53-scene-image { position: absolute; z-index: -2; width: 100%; height: 100%; object-fit: cover; object-position: center 55%; }
.b53-scene-opening::before { content: ''; position: absolute; inset: 0; z-index: -1; background: linear-gradient(90deg, rgb(9 27 24 / 85%), rgb(9 27 24 / 48%) 54%, rgb(9 27 24 / 8%)); }
.b53-scene-copy { width: min(1140px, calc(100% - 80px)); margin: auto; padding: 44px 0 50px; animation: b53-arrive .65s ease both; }
.b53-mark-kicker { font-size: 10px; font-weight: 650; line-height: 1.5; margin-bottom: 16px; }
.b53-scene-copy > .b53-mark-kicker { color: #e1eadb; }
.b53-scene-copy h1 { font-size: 48px; line-height: 1.3; max-width: 780px; }
.b53-scene-subtitle { font: 24px/1.6 var(--b53-serif); margin: 14px 0 8px; }
.b53-scene-deck { max-width: 600px; font-size: 14px; color: #f0f3ef; margin-bottom: 24px; line-height: 1.9; text-wrap: pretty; }
.b53-route-external { display: flex; flex-wrap: wrap; gap: 12px; }
.b53-route-action { display: inline-flex; justify-content: center; align-items: center; gap: 16px; min-height: 46px; padding: 11px 21px; color: white; background: var(--b53-jade); border: 1px solid #8da69f; border-radius: 3px; font-size: 14px; text-decoration: none; transition: transform .2s ease, background .2s ease; }
.b53-route-action:hover { color: white; background: var(--b53-jade-dark); transform: translateY(-3px); }
.b53-route-action--light { color: var(--b53-ink); background: #f7f9f8; border-color: #f7f9f8; }
.b53-route-action--light:hover { background: #f2dfdf; color: var(--b53-ink); }
.b53-scene-disclosure { font-size: 10px; margin: 12px 0 0; color: #e6eeeb; }
.b53-scene-location { position: absolute; bottom: 22px; right: 40px; display: flex; align-items: center; gap: 7px; padding: 5px 9px; font-size: 11px; background: rgb(11 29 25 / 75%); }
.b53-scene-location svg { width: 13px; height: 13px; }
.b53-read-metadata { max-width: 1220px; margin: auto; display: flex; justify-content: space-between; gap: 16px; padding: 18px 40px; border-bottom: 1px solid var(--b53-line); font-size: 11px; color: var(--b53-muted); }
.b53-read-metadata nav { display: flex; gap: 12px; }
.b53-read-metadata a { text-decoration: none; }
.b53-read-layout { max-width: 1220px; margin: auto; padding: 64px 40px 80px; display: grid; grid-template-columns: 215px minmax(0, 1fr); gap: 64px; }
.b53-route-rail { min-width: 0; }
.b53-route-desktop { position: sticky; top: 35px; }
.b53-route-desktop .b53-mark-kicker { color: var(--b53-berry); margin-bottom: 8px; }
.b53-route-title { font: 650 20px/1.5 var(--b53-serif); margin-bottom: 24px; }
.b53-route-desktop ol { list-style: none; padding: 0; margin: 0; }
.b53-route-desktop li { border-bottom: 1px solid var(--b53-line); }
.b53-route-desktop li a { display: flex; align-items: start; gap: 13px; padding: 13px 0; text-decoration: none; color: var(--b53-muted); font-size: 12px; line-height: 1.7; transition: padding-left .2s ease, color .2s ease; }
.b53-route-desktop li a span { font: 13px/1.7 var(--b53-serif); color: var(--b53-berry); flex: 0 0 12px; }
.b53-route-desktop li a:hover { padding-left: 6px; color: var(--b53-jade); }
.b53-proof-note { font-size: 11px; color: var(--b53-muted); margin: 25px 0 0; line-height: 2; }
.b53-proof-note svg { width: 14px; height: 14px; margin-right: 5px; }
.b53-proof-note time { margin-left: 23px; }
.b53-route-mobile { display: none; }
.b53-read-flow { min-width: 0; }
.b53-read-lead { font-size: 16px; line-height: 2; border-left: 3px solid var(--b53-jade); padding-left: 24px; margin-bottom: 40px; }
.b53-read-lead p:last-child { margin-bottom: 0; }
.b53-route-picks { display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid var(--b53-line); border-bottom: 1px solid var(--b53-line); margin: 0 0 48px; }
.b53-route-picks a { position: relative; text-decoration: none; padding: 22px 28px 24px 0; transition: background .2s ease; }
.b53-route-picks a + a { border-left: 1px solid var(--b53-line); padding-left: 22px; }
.b53-route-picks span { display: block; font-size: 10px; color: var(--b53-berry); margin-bottom: 7px; }
.b53-route-picks strong { font-family: var(--b53-serif); font-size: 18px; font-weight: 550; }
.b53-route-picks svg { position: absolute; right: 10px; top: 24px; width: 16px; }
.b53-route-picks a:hover { background: #ecf1ed; }
.b53-read-chapter { padding-bottom: 36px; margin-bottom: 36px; border-bottom: 1px solid var(--b53-line); scroll-margin-top: 24px; }
.b53-read-heading { display: flex; gap: 14px; align-items: baseline; margin-bottom: 24px; }
.b53-read-heading > span { color: var(--b53-berry); font: 16px/1 var(--b53-serif); flex: 0 0 16px; }
.b53-read-heading h2 { font-size: 27px; line-height: 1.55; }
.b53-read-chapter h3 { font-size: 17px; line-height: 1.7; margin: 28px 0 12px; color: var(--b53-jade-dark); }
.b53-read-chapter p { line-height: 2; }
.b53-read-chapter ul, .b53-read-chapter ol { padding-left: 23px; }
.b53-read-chapter li { margin-bottom: 10px; }
.b53-read-chapter li::marker { color: var(--b53-berry); }
.b53-read-chapter p:last-child { margin-bottom: 0; }
.b53-grid-compare, .b53-grid-costs { width: 100%; border-collapse: collapse; font-size: 13px; margin: 22px 0; table-layout: fixed; }
caption { text-align: left; color: var(--b53-muted); font-size: 11px; margin-bottom: 10px; }
th { text-align: left; background: #e9efeb; color: var(--b53-jade-dark); font-weight: 600; }
th, td { padding: 14px 12px; border-bottom: 1px solid var(--b53-line); vertical-align: top; overflow-wrap: anywhere; }
tbody tr { transition: background .2s ease; }
tbody tr:hover { background: #eef2ee; }
.b53-term-ledger { margin-top: 25px; padding: 3px 25px 20px; border-left: 2px solid var(--b53-berry); background: #f2f0ee; }
.b53-term-entry p:last-child { margin-bottom: 0; }
.b53-term-entry + .b53-term-entry { border-top: 1px solid #ddd6d2; margin-top: 22px; }
.b53-term-entry dfn { font-style: normal; }
.b53-term-entry h3 { color: var(--b53-berry); }
.b53-proof-question { border-bottom: 1px solid var(--b53-line); }
.b53-proof-question:first-child { border-top: 1px solid var(--b53-line); }
.b53-proof-question summary { display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 20px 0; cursor: pointer; list-style: none; transition: color .2s ease; }
summary::-webkit-details-marker { display: none; }
.b53-proof-question summary h3 { font: 550 16px/1.8 var(--b53-sans); margin: 0; color: inherit; }
.b53-proof-question summary:hover { color: var(--b53-jade); }
.b53-proof-question summary svg { transition: transform .22s ease; }
.b53-proof-question[open] summary svg { transform: rotate(45deg); }
.b53-proof-question[open] summary { color: var(--b53-jade); }
.b53-proof-answer { padding: 0 32px 23px 0; font-size: 15px; animation: b53-arrive .2s ease; }
.b53-proof-editor { padding: 22px 25px; background: #eaf0ed; border-left: 2px solid var(--b53-jade); font-size: 12px; color: var(--b53-muted); }
.b53-proof-editor p:last-child { margin-bottom: 0; }
.b53-media-band { border-top: 1px solid var(--b53-line); background: #edf1ee; }
.b53-media-wrap { max-width: 1220px; padding: 64px 40px 48px; margin: auto; }
.b53-media-heading { display: flex; justify-content: space-between; align-items: end; gap: 20px; margin-bottom: 28px; }
.b53-media-heading .b53-mark-kicker { color: var(--b53-berry); margin-bottom: 10px; }
.b53-media-heading h2 { font-size: 30px; margin-bottom: 10px; }
.b53-media-heading p:last-child { color: var(--b53-muted); font-size: 12px; margin-bottom: 0; }
.b53-media-controls { display: flex; gap: 8px; }
.b53-media-controls button { width: 44px; height: 44px; display: grid; place-items: center; border: 1px solid #b3c3bb; background: transparent; border-radius: 50%; color: var(--b53-jade); transition: background .2s; }
.b53-media-controls button:hover:not(:disabled) { background: #dce5de; }
.b53-media-reel { display: flex; gap: 24px; overflow-x: auto; overscroll-behavior-x: contain; scroll-snap-type: x mandatory; scrollbar-color: #a5b8ad transparent; scrollbar-width: thin; }
.b53-media-scene { flex: 0 0 calc(50% - 12px); min-width: 0; scroll-snap-align: start; margin: 0; }
.b53-media-frame { overflow: hidden; aspect-ratio: 3/2; background: #d8dfd9; }
.b53-media-scene img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.b53-media-scene:hover img { transform: scale(1.035); }
.b53-media-scene figcaption { display: flex; justify-content: space-between; gap: 15px; font-size: 11px; padding: 14px 0; color: var(--b53-muted); }
.b53-media-scene figcaption span:last-child { white-space: nowrap; }
.b53-media-credits { margin-top: 15px; border-top: 1px solid #d0dbd3; font-size: 11px; color: var(--b53-muted); }
.b53-media-credits summary { display: flex; align-items: center; justify-content: space-between; list-style: none; cursor: pointer; padding: 15px 0; }
.b53-media-credits ul { padding-left: 18px; }
.b53-media-credits li { margin-bottom: 12px; overflow-wrap: anywhere; }
.b53-media-credits[open] summary svg { transform: rotate(180deg); }
.b53-close-colophon { background: #183e35; color: #f1f3ed; }
.b53-close-wrap { max-width: 1220px; margin: auto; padding: 48px 40px 20px; display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.b53-close-brand { font: 24px/1.5 var(--b53-serif); text-decoration: none; color: white; }
.b53-close-wrap p { margin: 10px 0 5px; font-size: 13px; }
.b53-close-wrap small { color: #c3d2ca; font-size: 11px; }
.b53-close-wrap nav { display: flex; align-items: start; justify-content: end; gap: 22px; font-size: 12px; }
.b53-close-wrap nav a { color: #e3ece5; text-decoration: none; }
.b53-close-wrap a:hover { color: #f1d970; }
.b53-close-fine { grid-column: 1/-1; display: flex; justify-content: space-between; gap: 20px; border-top: 1px solid #476559; padding-top: 18px; color: #c3d2ca; font-size: 10px; }
.b53-read-missing { max-width: 640px; margin: 12vh auto; padding: 0 24px; }
.b53-read-missing h1 { font-size: 36px; margin-bottom: 16px; }
.b53-read-missing .b53-mark-kicker { color: var(--b53-berry); }
@keyframes b53-arrive { from { opacity: .4; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
@media (min-width: 1600px) { .b53-scene-opening { min-height: 500px; } }
@media (max-width: 1000px) {
  .b53-mark-wrap { padding-inline: 28px; }
  .b53-route-primary { gap: 20px; }
  .b53-mark-name span { display: none; }
  .b53-read-layout { gap: 35px; grid-template-columns: 180px minmax(0, 1fr); padding-inline: 28px; }
  .b53-read-heading h2 { font-size: 24px; }
  .b53-route-picks { grid-template-columns: 1fr; }
  .b53-route-picks a + a { border-left: 0; border-top: 1px solid var(--b53-line); padding-left: 0; }
  .b53-close-wrap nav { flex-wrap: wrap; gap: 15px; }
}
@media (max-width: 720px) {
  .b53-mark-wrap { min-height: auto; padding: 12px 20px 0; flex-wrap: wrap; gap: 10px; }
  .b53-mark-identity img { width: 42px; height: 42px; }
  .b53-mark-name { font-size: 21px; }
  .b53-mark-name span { display: block; font-size: 11px; }
  .b53-mark-identity small { font-size: 8px; }
  .b53-route-primary { width: 100%; justify-content: space-between; gap: 8px; border-top: 1px solid #eef1ee; }
  .b53-route-primary a { padding: 10px 0; font-size: 12px; }
  .b53-scene-opening { min-height: 415px; }
  .b53-scene-copy { width: calc(100% - 40px); padding: 32px 0 53px; }
  .b53-scene-copy h1 { font-size: 34px; max-width: 550px; }
  .b53-scene-subtitle { font-size: 21px; margin-top: 15px; }
  .b53-scene-deck { font-size: 13px; line-height: 1.9; margin-bottom: 22px; }
  .b53-scene-opening::before { background: linear-gradient(90deg, rgb(9 27 24 / 78%), rgb(9 27 24 / 48%)); }
  .b53-scene-image { object-position: 62% center; }
  .b53-route-external { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; max-width: 420px; }
  .b53-route-action { min-height: 46px; padding: 10px 12px; gap: 9px; font-size: 13px; }
  .b53-scene-disclosure { font-size: 9px; }
  .b53-scene-location { bottom: 13px; right: 20px; font-size: 9px; }
  .b53-read-metadata { padding: 14px 20px; font-size: 10px; }
  .b53-read-layout { padding: 24px 20px 45px; display: block; }
  .b53-route-desktop { display: none; }
  .b53-route-mobile { display: block; margin-bottom: 30px; border-top: 1px solid var(--b53-line); border-bottom: 1px solid var(--b53-line); }
  .b53-route-mobile summary { cursor: pointer; list-style: none; display: flex; justify-content: space-between; padding: 12px 0; color: var(--b53-jade); font-size: 13px; }
  .b53-route-mobile ol { padding-left: 22px; font-size: 13px; }
  .b53-route-mobile li { padding: 6px 0; }
  .b53-read-lead { font-size: 15px; padding-left: 17px; margin-bottom: 32px; }
  .b53-read-chapter { font-size: 15px; margin-bottom: 28px; padding-bottom: 28px; }
  .b53-read-heading { gap: 9px; margin-bottom: 18px; }
  .b53-read-heading h2 { font-size: 23px; }
  .b53-read-heading > span { flex-basis: 12px; font-size: 14px; }
  .b53-read-chapter h3 { font-size: 16px; }
  .b53-route-picks { margin-bottom: 34px; }
  .b53-route-picks strong { font-size: 19px; }
  .b53-grid-compare, .b53-grid-costs { display: block; font-size: 13px; }
  table caption, table tbody, table tr, table td { display: block; width: 100%; }
  table caption { font-size: 11px; }
  table thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  table tr { padding: 8px 0; border-bottom: 1px solid var(--b53-line); }
  table td { border: 0; display: grid; grid-template-columns: 5.5em minmax(0, 1fr); gap: 8px; padding: 7px 0; }
  table td::before { content: attr(data-b53-label); color: var(--b53-jade); font-size: 11px; }
  .b53-term-ledger { padding-inline: 16px; }
  .b53-proof-question summary { padding-block: 18px; }
  .b53-proof-question summary h3 { font-size: 15px; }
  .b53-proof-answer { padding-right: 0; font-size: 14px; }
  .b53-proof-editor { padding: 18px; }
  .b53-media-wrap { padding: 35px 20px; }
  .b53-media-heading { align-items: start; gap: 15px; }
  .b53-media-heading h2 { font-size: 25px; }
  .b53-media-heading p:last-child { font-size: 11px; }
  .b53-media-controls { gap: 6px; flex-shrink: 0; margin-top: 21px; }
  .b53-media-controls button { width: 36px; height: 36px; }
  .b53-media-reel { gap: 16px; }
  .b53-media-scene { flex-basis: 90%; }
  .b53-media-scene figcaption { font-size: 10px; }
  .b53-close-wrap { padding: 35px 20px 20px; grid-template-columns: 1fr; gap: 25px; }
  .b53-close-wrap nav { justify-content: start; }
  .b53-close-fine { flex-direction: column; gap: 5px; }
}
@media (max-width: 359px) {
  .b53-scene-copy h1 { font-size: 29px; }
  .b53-scene-subtitle { font-size: 18px; }
  .b53-route-action { padding-inline: 11px; gap: 6px; }
  .b53-mark-name span { display: none; }
  .b53-media-heading h2 { font-size: 22px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}