:root {
  --bg:#071820;
  --surface:#0c292b;
  --surface-warm:#103235;
  --fg:#efe4c9;
  --fg-2:#d3d3c9;
  --muted:#adb9b5;
  --meta:#c6a05d;
  --border:#47605c;
  --border-soft:#294747;
  --accent:#e4c47a;
  --accent-on:#071820;
  --accent-hover:color-mix(in oklab,var(--accent),black 8%);
  --accent-active:color-mix(in oklab,var(--accent),black 14%);
  --success:#4f8a4f;
  --warn:#c9822f;
  --danger:#ffb4a9;
  --seal:#7d3028;
  --gold:#c6a05d;
  --bronze:#59604a;
  --font-display:Georgia,"Times New Roman",serif;
  --font-body:Inter,system-ui,sans-serif;
  --font-mono:"SF Mono",ui-monospace,Menlo,monospace;
  --text-xs:12px;
  --text-sm:14px;
  --text-base:17px;
  --text-lg:20px;
  --text-xl:28px;
  --text-2xl:42px;
  --text-3xl:42px;
  --text-4xl:60px;
  --leading-body:1.62;
  --leading-tight:1;
  --tracking-display:-.025em;
  --space-1:4px;
  --space-2:8px;
  --space-3:12px;
  --space-4:16px;
  --space-5:20px;
  --space-6:24px;
  --space-8:32px;
  --space-12:48px;
  --section-y-desktop:64px;
  --section-y-tablet:56px;
  --section-y-phone:40px;
  --radius-sm:2px;
  --radius-md:2px;
  --radius-lg:2px;
  --radius-pill:9999px;
  --elev-flat:none;
  --elev-ring:0 0 0 1px var(--border);
  --elev-raised:0 20px 52px rgba(32,25,20,.12);
  --focus-ring:0 0 0 4px rgba(155,91,50,.24);
  --motion-fast:150ms;
  --motion-base:240ms;
  --ease-standard:cubic-bezier(.2,0,0,1);
  --container-max:1352px;
  --container-gutter-desktop:36px;
  --container-gutter-tablet:24px;
  --container-gutter-phone:16px;
  --immersive-night:#071820;
  --immersive-teal:#0b3432;
  --immersive-gold:#c79a45;
  --immersive-gold-highlight:#e4c47a;
  --immersive-parchment:#d8bd8a;
  --immersive-brown:#5a321d;
  --immersive-text:#f0e4cb;
}

*,*::before,*::after{box-sizing:border-box}
html{color-scheme:dark;scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{max-width:100%;margin:0;background-color:var(--bg);background-image:linear-gradient(rgba(7,24,32,.96),rgba(7,24,32,.96)),url("/assets/immersive/fresco-texture.webp");background-size:auto,720px 720px;color:var(--fg);font-family:var(--font-body);font-size:var(--text-base);line-height:var(--leading-body);text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased}
::selection{background:var(--accent);color:var(--accent-on)}
img,svg{display:block;max-width:100%}img{height:auto}a{color:inherit;text-decoration:none}button,input,textarea,select{font:inherit}button{cursor:pointer}p{margin-top:0;text-wrap:pretty}h1,h2,h3,h4{text-wrap:balance}
:focus-visible{outline:2px solid var(--accent);outline-offset:4px;box-shadow:none}[hidden]{display:none!important} :where(.container,.grid-2,.grid-3,.grid-1-2,.grid-2-1)>*{min-width:0}
.skip-link{position:fixed;left:var(--space-4);top:-80px;z-index:100;padding:var(--space-3) var(--space-4);background:var(--fg);color:var(--bg)}.skip-link:focus{top:var(--space-4)}
.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}
.container{width:min(100%,var(--container-max));margin-inline:auto;padding-inline:var(--container-gutter-desktop)}
.section{position:relative;padding-block:var(--section-y-desktop)}
.section+.section{border-top:1px solid var(--border-soft)}
.soft-section{background-color:color-mix(in oklab,var(--bg) 82%,var(--surface));background-image:url("assets/paper-fiber.svg");background-size:320px 320px}
.stack{display:flex;flex-direction:column}.stack>*+*{margin-top:var(--space-5)}
.row{display:flex;align-items:center;gap:var(--space-5)}.row-between{display:flex;align-items:center;justify-content:space-between;gap:var(--space-5)}
.grid-2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--space-8)}
.grid-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:var(--space-8)}
.grid-4{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:var(--space-5)}
.grid-2-1{display:grid;grid-template-columns:minmax(0,2fr) minmax(280px,1fr);gap:var(--space-12);align-items:start}
.grid-1-2{display:grid;grid-template-columns:minmax(260px,1fr) minmax(0,2fr);gap:var(--space-12);align-items:start}
h1,h2,h3,h4,.h1,.h2,.h3{font-family:var(--font-display);color:var(--fg);margin:0;font-variant-ligatures:common-ligatures discretionary-ligatures}
h1,.h1{font-size:clamp(var(--text-2xl),6vw,var(--text-4xl));line-height:var(--leading-tight);letter-spacing:var(--tracking-display);font-weight:500}
h2,.h2{font-size:clamp(var(--text-xl),4vw,var(--text-3xl));line-height:1.08;letter-spacing:var(--tracking-display);font-weight:500}
h3,.h3{font-size:var(--text-xl);line-height:1.22;font-weight:500}h4{font-size:var(--text-lg);line-height:1.3}
.lead{color:var(--fg-2);font-size:var(--text-lg);line-height:1.6;max-width:56ch;margin:0}
.eyebrow{display:flex;align-items:center;gap:var(--space-3);color:var(--accent);font-family:var(--font-mono);font-size:var(--text-xs);font-weight:650;letter-spacing:.13em;text-transform:uppercase;margin:0 0 var(--space-5)}
.eyebrow::before{content:"";width:38px;border-top:2px solid var(--gold)}
.meta{color:var(--muted);font-family:var(--font-mono);font-size:var(--text-xs);font-weight:560}.num{font-family:var(--font-mono);font-variant-numeric:tabular-nums}

.btn{min-height:48px;max-width:100%;display:inline-flex;align-items:center;justify-content:center;gap:var(--space-2);padding:14px var(--space-5);border:1px solid transparent;border-radius:var(--radius-sm);font-weight:680;font-size:var(--text-sm);letter-spacing:.01em;text-align:center;white-space:normal;transition:transform var(--motion-fast) var(--ease-standard),background var(--motion-fast) var(--ease-standard),border-color var(--motion-fast) var(--ease-standard)}
.btn:active{transform:translateY(1px)}.btn-primary{background:var(--accent);color:var(--accent-on);border-color:var(--accent);box-shadow:none}.btn-primary:hover{background:var(--accent-hover);border-color:var(--accent-hover);color:var(--accent-on);transform:translateY(1px)}
.btn-secondary{background:transparent;color:var(--accent);border-color:var(--accent)}.btn-secondary:hover,.btn-ghost:hover{background:color-mix(in oklab,var(--accent) 7%,var(--surface));color:var(--accent-active)}
.btn-ghost{background:transparent;color:var(--fg);border-color:transparent}.btn-arrow::after{content:"→"}.text-link{color:var(--accent);font-weight:680;text-decoration:underline;text-underline-offset:4px}.text-link:hover{background:color-mix(in oklab,var(--accent) 7%,var(--surface));color:var(--accent-active);text-decoration:none}

.hero{position:relative;isolation:isolate;display:flex;align-items:center;padding-block:56px}
.hero::before{content:"";position:absolute;z-index:-1;top:24px;right:0;width:min(26vw,360px);aspect-ratio:1;background:url("assets/porcelain-corner.svg") repeat;background-size:96px 96px;opacity:.16;transform:rotate(90deg);pointer-events:none}
.hero-split{display:grid;grid-template-columns:minmax(0,6fr) minmax(0,5fr);gap:clamp(var(--space-8),7vw,92px);align-items:center;width:100%}
.hero-center{text-align:center;max-width:860px;margin-inline:auto}.hero-center .eyebrow{justify-content:center}.hero-center .lead{margin-inline:auto}.hero h1{max-width:20ch;margin-bottom:20px}.hero-center h1{max-width:none}
.hero-cta{display:flex;align-items:center;flex-wrap:wrap;gap:var(--space-3);margin-top:var(--space-8)}.hero-center .hero-cta{justify-content:center}
.archive-mark{display:inline-flex;align-items:center;gap:var(--space-3);margin-bottom:var(--space-6);color:var(--muted)}.archive-mark span{width:40px;height:58px;display:grid;place-items:center;background:color-mix(in oklab,var(--seal) 5%,var(--surface));border:2px solid var(--seal);border-radius:2px;color:var(--seal);box-shadow:inset 0 0 0 3px var(--surface);font-family:Georgia,"Noto Serif SC",serif;font-weight:700;writing-mode:vertical-rl}.archive-mark small{font-family:var(--font-mono);font-size:10px;line-height:1.45;letter-spacing:.14em;text-align:left}
.museum-frame{position:relative;isolation:isolate;background:var(--surface);border:1px solid var(--gold);border-radius:var(--radius-md);padding:16px 58px 16px 16px;box-shadow:0 18px 48px rgba(32,25,20,.13),inset 0 0 0 5px var(--surface),inset 0 0 0 6px color-mix(in oklab,var(--accent) 32%,var(--border))}
.museum-frame::before{content:"";position:absolute;z-index:2;top:4px;right:4px;width:96px;height:96px;background:url("assets/porcelain-corner.svg") no-repeat top right/96px;pointer-events:none}.museum-frame img{width:100%;max-height:520px;object-fit:cover;border-radius:calc(var(--radius-sm) - 2px);filter:sepia(.12) saturate(.78) contrast(1.06)}
.collection-mark{position:absolute;z-index:3;top:112px;right:13px;min-width:36px;padding:var(--space-2) var(--space-1);display:grid;place-items:center;background:var(--accent);border-radius:2px;color:var(--accent-on);font-family:var(--font-display);font-size:var(--text-sm);line-height:1;letter-spacing:.12em;writing-mode:vertical-rl}.image-caption{display:flex;justify-content:space-between;gap:var(--space-4);color:var(--muted);font-family:var(--font-mono);font-size:10px;letter-spacing:.04em;margin-top:var(--space-3)}

.section-head{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(240px,.7fr);gap:24px;align-items:end;margin-bottom:28px;padding-bottom:20px;border-bottom:1px solid var(--gold);position:relative}.section-head::after{content:"";position:absolute;bottom:-2px;left:0;width:96px;border-bottom:3px solid var(--accent)}.section-head .lead{font-size:var(--text-base)}
.card{position:relative;isolation:isolate;overflow:hidden;background:color-mix(in oklab,var(--surface) 97%,var(--bg));border:1px solid var(--border);border-top:3px solid var(--accent);border-radius:var(--radius-md);padding:clamp(var(--space-5),3vw,var(--space-8));box-shadow:var(--elev-ring);transition:transform var(--motion-base) var(--ease-standard),box-shadow var(--motion-base) var(--ease-standard),border-color var(--motion-base) var(--ease-standard)}
.card::after{content:"";position:absolute;z-index:0;top:0;right:0;width:82px;height:82px;background:url("assets/porcelain-corner.svg") no-repeat top right/82px;opacity:.46;pointer-events:none}.card>*{position:relative;z-index:1}a.card:hover{border-color:color-mix(in oklab,var(--accent) 60%,var(--border));box-shadow:var(--elev-raised);transform:translateY(-3px)}.card h3{margin-bottom:var(--space-3)}.card p{color:var(--fg-2)}
.card-flat{background:transparent;border:0;padding:0}.card-rule{background:transparent;border:0;border-top:1px solid var(--gold);box-shadow:inset 0 3px 0 color-mix(in oklab,var(--accent) 16%,transparent);padding:var(--space-6) 0 0}.card-rule h3{margin-bottom:var(--space-3)}.card-rule p{color:var(--fg-2)}
.card-kicker{color:var(--accent);font-family:var(--font-mono);font-size:10px;font-weight:650;letter-spacing:.08em;text-transform:uppercase;display:flex;justify-content:space-between;gap:var(--space-3);margin-bottom:var(--space-6);padding-bottom:var(--space-3);border-bottom:1px solid var(--border-soft)}
.pill,.tag,.filter-chip{min-height:36px;display:inline-flex;align-items:center;justify-content:center;padding:var(--space-1) var(--space-3);border:1px solid color-mix(in oklab,var(--accent) 30%,var(--border));border-radius:var(--radius-sm);color:var(--accent);background:color-mix(in oklab,var(--accent) 5%,var(--surface));font-family:var(--font-mono);font-size:10px;font-weight:650;letter-spacing:.04em;text-transform:uppercase}
.resource-meta{display:flex;flex-wrap:wrap;gap:var(--space-2);margin:var(--space-5) 0}

.cta-strip{text-align:center}.cta-strip .lead{margin:var(--space-4) auto var(--space-8)}
.cta-strip--contrast{background:var(--surface);color:var(--fg);padding-block:clamp(32px,5vw,56px)}.cta-strip--contrast h2,.cta-strip--contrast .eyebrow{color:var(--fg)}.cta-strip--contrast .eyebrow{justify-content:center}.cta-strip--contrast .eyebrow::before{border-color:var(--gold)}.cta-strip--contrast .btn{background:var(--surface);border-color:var(--surface);color:var(--accent);box-shadow:none}.cta-strip--contrast .btn:hover{background:var(--bg)}

.breadcrumb{display:flex;flex-wrap:wrap;align-items:center;gap:var(--space-2);color:var(--muted);font-size:var(--text-sm);padding-top:var(--space-6)}.breadcrumb a:hover{color:var(--accent);text-decoration:underline;text-underline-offset:4px}.breadcrumb span::before{content:"/";margin-right:var(--space-2);color:var(--gold)}
.lesson-intro{padding-block:clamp(56px,8vw,92px)}.lesson-intro h1{max-width:18ch}.lesson-intro .lead{margin-top:var(--space-5)}.lesson-facts{margin:var(--space-6) 0 0;padding-top:var(--space-5);border-top:1px solid var(--gold);display:flex;flex-wrap:wrap;gap:var(--space-3);align-items:center}.curriculum-fit{flex-basis:100%;color:var(--fg-2);font-size:var(--text-sm);margin:var(--space-1) 0 0}
.preview-stage{position:relative;isolation:isolate;overflow:hidden;background:color-mix(in oklab,var(--gold) 9%,var(--surface-warm));border:1px solid var(--gold);border-radius:var(--radius-md);box-shadow:inset 0 0 0 5px var(--surface),inset 0 0 0 6px rgba(185,138,72,.35);padding:var(--space-6)}
.slide-preview{position:relative;z-index:1;aspect-ratio:16/9;background-color:color-mix(in oklab,var(--surface) 97%,var(--bg));background-image:url("assets/paper-fiber.svg");border:1px solid color-mix(in oklab,var(--accent) 36%,var(--border));padding:clamp(var(--space-5),5vw,var(--space-12));display:none;overflow:hidden}.slide-preview.is-active{display:flex;flex-direction:column;justify-content:space-between}.slide-preview h3{font-size:clamp(var(--text-xl),4vw,var(--text-3xl));max-width:15ch}.slide-preview p{color:var(--fg-2);max-width:46ch;margin:0}.slide-placeholder{height:100%;display:flex;flex-direction:column;justify-content:space-between}.slide-placeholder::after{content:"";position:absolute;right:-30px;bottom:-34px;width:190px;height:190px;border:1px solid var(--gold);border-radius:50%;opacity:.25}.preview-controls{position:relative;z-index:1;display:flex;align-items:center;justify-content:space-between;margin-top:var(--space-4)}.preview-actions{display:flex;gap:var(--space-2)}.icon-btn{width:44px;height:44px;display:grid;place-items:center;border:1px solid var(--accent);border-radius:var(--radius-sm);background:var(--surface);color:var(--accent)}.icon-btn:hover{background:var(--accent);color:var(--accent-on)}
.download-panel{position:sticky;top:104px;border-top-color:var(--seal);box-shadow:0 18px 44px rgba(32,25,20,.1)}.download-panel .card-kicker{color:var(--seal)}.download-panel h2{font-size:var(--text-2xl)}.download-panel .adapt-line{padding-top:var(--space-5);border-top:1px solid var(--border-soft);color:var(--fg-2);font-size:var(--text-sm)}
.download-cta{width:100%;margin-top:var(--space-3)}.download-cta.is-disabled{cursor:not-allowed;background:var(--muted);border-color:var(--muted);box-shadow:none;opacity:.72}.download-unavailable{margin:var(--space-3) 0 var(--space-6);color:var(--muted);font-size:var(--text-xs);line-height:1.5}.optional-subscribe{margin-top:var(--space-8);padding-top:var(--space-6);border-top:1px solid var(--gold)}.optional-subscribe h3{font-size:var(--text-lg);margin-bottom:var(--space-2)}.optional-subscribe>p{color:var(--muted);font-size:var(--text-sm)}.optional-subscribe .btn{width:100%}
.check-list{list-style:none;padding:0;margin:var(--space-6) 0}.check-list li{position:relative;padding-left:26px;margin-top:var(--space-3);color:var(--fg-2)}.check-list li::before{content:"✓";position:absolute;left:0;color:var(--accent);font-weight:700}
.field{display:flex;flex-direction:column;gap:var(--space-2);margin-bottom:var(--space-5)}.field label{color:var(--fg-2);font-size:var(--text-sm)}.input,.textarea,.select{width:100%;min-height:48px;padding:12px 14px;border:0;border:1px solid var(--border);border-radius:2px;background:var(--bg);color:var(--fg)}.textarea{min-height:112px;resize:vertical}.input:focus,.textarea:focus,.select:focus{outline:2px solid var(--accent);outline-offset:2px;box-shadow:none}.field-error{min-height:0;color:var(--danger);font-size:var(--text-xs);margin:0}.form-status{display:none;margin-top:var(--space-5);padding:var(--space-4);border:1px solid color-mix(in oklab,var(--success) 45%,var(--border));border-radius:var(--radius-sm);background:color-mix(in oklab,var(--success) 7%,var(--surface));color:var(--fg-2)}.form-status.is-visible{display:block}.form-status strong{display:block;color:var(--fg);margin-bottom:var(--space-1)}
.process{counter-reset:process}.process-step{counter-increment:process;display:grid;grid-template-columns:72px 1fr;gap:var(--space-5);padding:var(--space-6) 0;border-top:1px solid var(--border)}.process-step::before{content:counter(process,decimal-leading-zero);font-family:var(--font-mono);color:var(--muted)}.process-step p{margin:var(--space-2) 0 0;color:var(--fg-2)}
.accordion{border-top:3px double var(--fg)}.accordion-item{border-bottom:1px solid var(--border)}.accordion-trigger{width:100%;min-height:64px;display:flex;align-items:center;justify-content:space-between;gap:var(--space-5);padding:var(--space-4) 0;border:0;background:transparent;color:var(--fg);text-align:left;font-family:var(--font-display);font-size:var(--text-lg)}.accordion-trigger::after{content:"+";font-family:var(--font-mono)}.accordion-trigger[aria-expanded="true"]::after{content:"−"}.accordion-panel{display:none;color:var(--fg-2);padding:0 0 var(--space-5)}.accordion-panel.is-open{display:block}
.other-lessons{display:flex;flex-wrap:wrap;gap:var(--space-3);justify-content:center;margin-top:var(--space-8)}
.trust-copy{max-width:840px}.trust-copy p{font-size:var(--text-lg);color:var(--fg-2)}.trust-promise{margin-top:var(--space-8);padding:var(--space-8);border:1px solid var(--gold);border-left:4px solid var(--accent);background:var(--surface)}

.pagefoot{position:relative;background:var(--bg);border-top:1px solid var(--gold);color:var(--muted);padding-block:40px;font-size:14px}.foot-grid{display:grid;grid-template-columns:2fr 1fr;gap:var(--space-8);align-items:start}.foot-grid strong,.foot-links b{color:var(--fg);font-family:var(--font-display);font-size:var(--text-lg)}.foot-links{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:var(--space-5)}.foot-links a:hover{color:var(--accent);text-decoration:underline;text-decoration-color:var(--gold);text-underline-offset:4px}.foot-note{border-top:1px solid rgba(255,255,255,.25);margin-top:var(--space-8);padding-top:var(--space-5);display:flex;justify-content:space-between;gap:var(--space-5)}

.feature .feature-mark{width:36px;height:36px;display:grid;place-items:center;border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--fg);margin-bottom:var(--space-5)}.feature .feature-mark svg{width:18px}.feature p{color:var(--fg-2);font-size:var(--text-sm)}
.topic-index{border-top:1px solid var(--gold)}.topic-row{display:grid;grid-template-columns:110px 1fr auto;gap:var(--space-8);align-items:baseline;padding:var(--space-6) var(--space-3);border-bottom:1px solid var(--border)}.topic-row h3{font-size:var(--text-lg)}.topic-row p{color:var(--muted);font-size:var(--text-sm);margin:var(--space-1) 0 0}.topic-row:hover{background:color-mix(in oklab,var(--accent) 5%,var(--surface))}.pull{text-align:right}
.timeline{border-left:3px double var(--fg);margin-left:var(--space-2)}.timeline-item{position:relative;display:grid;grid-template-columns:120px 1fr;gap:var(--space-6);padding:0 0 var(--space-8) var(--space-8)}.timeline-item::before{content:"";position:absolute;left:-5px;top:8px;width:9px;height:9px;border-radius:50%;background:var(--accent)}.timeline-item time{color:var(--muted);font-family:var(--font-mono);font-size:var(--text-xs)}.timeline-item p{color:var(--fg-2)}
.person-list{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--space-5)}.person{border-top:1px solid var(--fg);padding-top:var(--space-5)}.person b{font-family:var(--font-display);font-size:var(--text-xl);font-weight:500}.person p{color:var(--fg-2);font-size:var(--text-sm)}
.dynasty-track{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:var(--space-2);margin-top:var(--space-12)}.era{padding-top:var(--space-4);border-top:1px solid var(--gold)}.era-hanzi{width:44px;height:44px;display:grid;place-items:center;background:var(--surface);border:1px solid var(--accent);color:var(--accent);font-family:Georgia,serif;font-size:24px}.era strong{display:block;font-family:var(--font-display);font-size:var(--text-lg);margin-top:var(--space-3)}.era>span:not(.era-hanzi){color:var(--muted);font-family:var(--font-mono);font-size:10px}
.filter-row{display:flex;flex-wrap:wrap;gap:var(--space-2)}.filter-chip{cursor:pointer}.filter-chip:hover,.filter-chip[aria-pressed="true"]{background:var(--accent);color:var(--accent-on)}
.toc{position:sticky;top:104px}.toc strong{font-family:var(--font-display)}.toc a{display:block;min-height:40px;padding:var(--space-2) 0;color:var(--muted);border-bottom:1px solid var(--border-soft)}.toc a:hover{color:var(--accent)}
.article{max-width:720px}.article h2{font-size:var(--text-2xl);margin:var(--section-y-phone) 0 var(--space-5)}.article h2:first-child{margin-top:0}.article p{color:var(--fg-2)}
.fact-box{border-block:3px double var(--fg);padding-block:var(--space-6);margin-block:var(--space-8);display:grid;grid-template-columns:repeat(3,1fr);gap:var(--space-5)}.fact-box span{display:block;color:var(--muted);font-family:var(--font-mono);font-size:var(--text-xs)}.fact-box strong{font-family:var(--font-display);font-size:var(--text-lg)}
.log-row{display:grid;grid-template-columns:120px 1fr 96px;gap:var(--space-8);padding:var(--space-6) var(--space-3);border-top:1px solid var(--border);align-items:baseline}.log-row:last-child{border-bottom:1px solid var(--border)}.log-row h3{font-size:var(--text-lg)}.log-row p{margin:var(--space-1) 0 0;color:var(--muted);font-size:var(--text-sm)}.log-row:hover{background:var(--surface)}.search-box{display:flex;align-items:center;gap:var(--space-3);border-bottom:1px solid var(--muted)}.search-box svg{width:18px;color:var(--muted)}.search-box .input{border:0}.search-box:focus-within{border-bottom:2px solid var(--accent)}
.hidden{display:none!important}.empty-state{display:none;text-align:center;color:var(--muted);padding:var(--space-12)}.empty-state.is-visible{display:block}


/* One navigation component: normal-flow on information pages, overlaid on visual heroes. */
.topnav{position:relative;z-index:30;background:var(--bg);border-bottom:1px solid rgba(198,160,93,.5)}
.topnav-inner{position:relative;min-height:80px;display:grid;grid-template-columns:1fr auto 1fr;gap:24px;align-items:center}
.logo{position:relative;grid-column:1;grid-row:1;justify-self:start;min-height:48px;padding-left:58px;display:flex;flex-direction:column;justify-content:center;color:var(--fg);font-family:var(--font-display);font-size:20px;font-weight:600;line-height:1.2}
.logo::before{content:"史";position:absolute;left:0;top:50%;transform:translateY(-50%);width:44px;height:44px;display:grid;place-items:center;background:rgba(7,24,32,.8);border:1px solid var(--gold);color:var(--accent);font-size:25px;box-shadow:inset 0 0 0 3px rgba(198,160,93,.12)}
.logo small{margin-top:4px;color:var(--muted);font-family:var(--font-mono);font-size:9px;letter-spacing:.1em;text-transform:uppercase}
.home-rosette,.nav-rosette{grid-column:2;grid-row:1;width:62px;height:62px;pointer-events:none}
.topnav nav{grid-column:3;grid-row:1;justify-self:end;display:flex;align-items:center;gap:28px}
.topnav nav a{min-height:44px;display:inline-flex;align-items:center;border-bottom:1px solid transparent;color:var(--fg);font-size:14px;font-weight:600}
.topnav nav a:hover,.topnav nav a[aria-current="page"]{color:var(--accent);border-color:var(--gold)}
.menu-toggle{display:none;width:44px;height:44px;border:1px solid var(--gold);background:var(--bg);color:var(--accent);align-items:center;justify-content:center}
.menu-toggle svg{width:22px}
.home-page .topnav,.lesson-page .topnav{position:absolute;inset:0 0 auto;background:rgba(7,24,32,.36)}

/* Shared museum reading surfaces. No light page panels. */
.museum-section{position:relative;padding-block:48px}
.museum-panel{padding:32px;border:1px solid var(--border);border-top-color:var(--gold);border-radius:2px;background-color:var(--surface);background-image:linear-gradient(rgba(12,41,43,.96),rgba(12,41,43,.96)),url("/assets/immersive/fresco-texture.webp");background-size:auto,720px 720px}
.museum-panel p{color:var(--fg-2)}
.museum-section-heading{margin-bottom:24px;padding-bottom:18px;border-bottom:1px solid var(--gold)}
.museum-section-heading h2{font-size:clamp(28px,3vw,38px);line-height:1.15}
.museum-section-heading p{margin:8px 0 0;color:var(--fg-2);font-size:16px}
.gold-divider{display:flex;align-items:center;gap:16px;color:var(--accent);font-size:12px;letter-spacing:.06em}
.gold-divider::before,.gold-divider::after{content:"";flex:1;border-top:1px solid var(--border)}
.btn-primary{background:var(--surface-warm);color:var(--fg);border-color:var(--gold)}
.btn-primary:hover{background:#1b4340;color:var(--fg);border-color:var(--accent)}
.btn-secondary{color:var(--fg);border-color:var(--border);background:transparent}
.btn-secondary:hover{color:var(--fg);border-color:var(--gold);background:var(--surface)}
.btn-ghost{color:var(--fg)}
input::placeholder,textarea::placeholder{color:var(--muted);opacity:1}
fieldset{min-width:0;margin:0;padding:0;border:0}
fieldset:disabled :is(input,select,textarea){opacity:1;color:var(--muted);cursor:not-allowed;-webkit-text-fill-color:var(--muted)}
button:disabled{background:var(--surface);color:var(--muted);border-color:var(--border);cursor:not-allowed;box-shadow:none}
.field-hint{font-size:13px;color:var(--muted);margin:0}
.field-error:empty{display:none}
.field label{color:var(--fg)}
.foot-links a{display:inline-flex;align-items:center;min-height:44px}
.foot-grid p{margin:8px 0 0}

/* Home hero retains independent image, texture, route, and floral layers. */
.immersive-home{position:relative;isolation:isolate;min-height:100svh;overflow:hidden;background:var(--bg)}
.immersive-home-media,.immersive-home-media img,.immersive-home-veil,.immersive-home-texture{position:absolute;inset:0;width:100%;height:100%}
.immersive-home-media{z-index:-4}.immersive-home-media img{object-fit:cover;object-position:center}
.immersive-home-veil{z-index:-3;background:rgba(3,15,18,.44);box-shadow:inset 0 -160px 140px rgba(7,24,32,.72)}
.immersive-home-texture{z-index:-2;object-fit:cover;opacity:.16;mix-blend-mode:soft-light;pointer-events:none}
.immersive-home-copy{position:relative;z-index:2;display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100svh;padding-block:126px 150px;text-align:center}
.immersive-kicker{margin:0 0 16px;color:var(--accent);font-family:var(--font-mono);font-size:12px;letter-spacing:.17em;text-transform:uppercase}
.immersive-home h1{max-width:1100px;color:var(--fg);font-size:clamp(48px,6.5vw,92px);line-height:.98;letter-spacing:.045em;text-transform:uppercase;text-shadow:0 3px 20px #071820}
.immersive-subtitle{margin:24px 0 0;color:var(--accent);font-family:var(--font-display);font-size:clamp(23px,2.2vw,32px);line-height:1.25}
.immersive-summary{max-width:64ch;margin:16px auto 0;color:var(--fg-2);font-size:17px;line-height:1.55;text-shadow:0 1px 8px #071820}
.immersive-actions,.lesson-hero-actions{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:16px 28px;margin-top:24px}
.immersive-button{min-height:48px;max-width:100%;display:inline-flex;align-items:center;justify-content:center;padding:13px 24px;border:1px solid var(--accent);background:rgba(7,24,32,.88);color:var(--accent);font-size:14px;font-weight:650;letter-spacing:.02em;text-align:center;box-shadow:inset 0 0 0 2px rgba(198,160,93,.12)}
.immersive-button:hover{background:var(--surface-warm);border-color:var(--fg)}
.immersive-text-link{min-height:44px;display:inline-flex;align-items:center;justify-content:center;border-bottom:1px solid var(--gold);color:var(--fg);font-size:14px;font-weight:600;text-align:center}
.immersive-text-link:hover{color:var(--accent)}
.immersive-home-route{position:absolute;z-index:1;left:3%;bottom:48px;width:94%;height:auto;max-height:160px;opacity:.75;pointer-events:none}
.immersive-home-floral{position:absolute;bottom:0;left:0;width:100%;height:42px;object-fit:cover;border-top:1px solid var(--gold);background:var(--immersive-teal);pointer-events:none}
.home-hero-caption{position:absolute;bottom:52px;left:16px;right:16px;margin:0;color:var(--muted);font-size:11px;text-align:center}

/* Portrait collection only. Intrinsic 4:5 art sets height; the header is not fixed. */
.home-lesson-collection{scroll-margin-top:0;padding-block:32px 40px;background-image:linear-gradient(rgba(7,24,32,.91),rgba(7,24,32,.97)),url("/assets/immersive/fresco-texture.webp");background-size:auto,720px 720px}
.home-lesson-collection>.container{width:calc(100% - 80px);max-width:1320px;padding-inline:0}
.home-lesson-collection .museum-section-heading{margin-bottom:24px;padding:0;border:0;text-align:center}
.home-lesson-collection .museum-section-heading h2{font-size:clamp(28px,3vw,40px);line-height:1.15}
.home-lesson-collection .lesson-collection-label{display:flex;align-items:center;justify-content:center;gap:18px;margin:0 0 12px;color:var(--accent);font-family:var(--font-mono);font-size:11px;line-height:1.5;letter-spacing:.2em;text-transform:uppercase}
.home-lesson-collection .lesson-collection-label::before,.home-lesson-collection .lesson-collection-label::after{content:"";flex:1;border-top:1px solid var(--border)}
.home-lesson-collection .lesson-card-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.home-lesson-collection .lesson-card{min-width:0;display:flex;flex-direction:column;border:1px solid var(--gold);border-radius:2px;background:var(--surface);box-shadow:0 8px 18px rgba(0,0,0,.18);transition:border-color .2s,transform .2s}
.home-lesson-collection .lesson-card__visual{position:relative;display:block;aspect-ratio:4/5;background:var(--bg)}
.home-lesson-collection .lesson-card__image{display:block;width:100%;height:auto;aspect-ratio:4/5}
.home-lesson-collection .lesson-card__frame{position:absolute;inset:0;width:100%;height:100%;object-fit:contain;pointer-events:none}
.home-lesson-collection .lesson-card__body{flex:1;display:flex;flex-direction:column;padding:18px 20px 20px;border-top:1px solid var(--border);text-align:center}
.lesson-status{display:inline-block;align-self:flex-start;width:max-content;max-width:100%;margin:0;padding:5px 8px;border:1px solid rgba(198,160,93,.45);color:var(--accent);background:rgba(198,160,93,.05);font-size:11px;line-height:1.35;letter-spacing:.02em}
.home-lesson-collection .lesson-status{align-self:center;letter-spacing:.12em}
.home-lesson-collection .lesson-card h3{font-size:28px;line-height:1.2;margin:10px 0 8px}
.home-lesson-collection .lesson-card h3 a:hover{color:var(--accent)}
.home-lesson-collection .lesson-card__meta{margin:0;color:var(--fg-2);font-size:15px;line-height:1.5}
.home-lesson-collection .lesson-card__actions{display:grid;gap:10px;margin-top:auto;padding-top:14px}
.home-lesson-collection .lesson-card__actions .btn{width:100%;min-height:46px;padding:10px 12px;font-size:15px;line-height:1.5;gap:10px}
.home-lesson-collection .lesson-card__visual:focus-visible{outline-offset:-4px}
.home-lesson-collection .lesson-collection-end{display:flex;align-items:center;gap:14px;margin-top:28px;color:var(--gold)}
.home-lesson-collection .lesson-collection-end::before,.home-lesson-collection .lesson-collection-end::after{content:"";flex:1;border-top:1px solid var(--border)}
.home-lesson-collection .lesson-collection-end span{width:8px;height:8px;border:1px solid currentColor;transform:rotate(45deg)}
.home-lesson-collection .lesson-card--available .lesson-status{background:var(--accent);color:var(--bg);border-color:var(--accent);font-weight:700}
.home-lesson-collection .lesson-card--available .lesson-card__actions{grid-template-columns:1.15fr 1fr}
.home-lesson-collection .lesson-card--available .lesson-card__actions .btn{padding-inline:8px;font-size:14px;gap:5px}
@media(max-width:399px),(min-width:700px) and (max-width:850px){
  .home-lesson-collection .lesson-card--available .lesson-card__actions{grid-template-columns:1fr}
}
@media(min-width:700px) and (max-width:1099px){
  .home-lesson-collection>.container{width:calc(100% - 64px)}
  .home-lesson-collection .lesson-card-grid{grid-template-columns:repeat(4,minmax(0,1fr))}
  .home-lesson-collection .lesson-card{grid-column:span 2}
  .home-lesson-collection .lesson-card:last-child:nth-child(odd){grid-column:2/span 2}
}
@media(max-width:699px){
  .home-lesson-collection{padding-block:28px 32px}
  .home-lesson-collection>.container{width:calc(100% - 40px)}
  .home-lesson-collection .museum-section-heading{margin-bottom:22px}
  .home-lesson-collection .lesson-collection-label{gap:10px;letter-spacing:.14em}
  .home-lesson-collection .lesson-card-grid{grid-template-columns:1fr;gap:28px}
}
.lesson-download-control.is-available{background:var(--accent);color:var(--bg)}
[data-lesson-download]:empty{display:none}
.home-custom-band{padding-block:0 48px}
.home-custom-panel{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:32px;padding:28px 32px}
.home-custom-panel h2{font-size:clamp(26px,2.6vw,34px);max-width:28ch}
.home-custom-panel .eyebrow{margin-bottom:10px}
.home-custom-panel p:last-child{max-width:65ch;margin:12px 0 0}
.catalog-noscript{padding:20px;border:1px solid var(--gold)}

/* One resource layout for all three lessons, with content-driven hero height. */
.lesson-hero{position:relative;isolation:isolate;overflow:hidden;background:var(--bg)}
.lesson-hero-media,.lesson-hero-media img,.lesson-hero-veil,.lesson-hero-texture{position:absolute;inset:0;width:100%;height:100%}
.lesson-hero-media{z-index:-4}.lesson-hero-media img{object-fit:cover;object-position:center}
.lesson-hero-veil{z-index:-3;background:rgba(3,15,18,.61);box-shadow:inset 0 -100px 100px rgba(7,24,32,.7)}
.lesson-hero-texture{z-index:-2;object-fit:cover;opacity:.15;mix-blend-mode:soft-light;pointer-events:none}
.lesson-hero-content{position:relative;z-index:2;display:flex;flex-direction:column;align-items:center;text-align:center;padding-block:96px 76px}
.breadcrumb--dark{align-self:stretch;padding:0;color:var(--muted);text-align:left;font-size:13px}
.breadcrumb--dark a{display:inline-flex;align-items:center;min-height:32px}
.lesson-status--hero{align-self:center;margin-top:14px;background:rgba(7,24,32,.65)}
.lesson-hero h1{max-width:22ch;margin:12px 0 0;font-size:clamp(38px,4.5vw,62px);line-height:1.04;letter-spacing:.025em}
.lesson-hero-deck{margin:14px 0 0;color:var(--accent);font-family:var(--font-display);font-size:clamp(21px,2vw,28px);line-height:1.25}
.lesson-hero-summary{max-width:70ch;margin:14px auto 0;color:var(--fg-2);font-size:16px;line-height:1.5}
.lesson-hero-meta{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));width:min(100%,800px);margin:20px 0 0;border-block:1px solid var(--border)}
.lesson-hero-meta div{padding:10px 16px}.lesson-hero-meta div+div{border-left:1px solid var(--border)}
.lesson-hero-meta dt{font-size:11px;color:var(--muted);line-height:1.5}
.lesson-hero-meta dd{margin:4px 0 0;font-size:16px;color:var(--fg)}
.lesson-curriculum{max-width:80ch;margin:12px auto 0;font-size:14px;line-height:1.5;color:var(--fg-2)}
.lesson-curriculum strong{color:var(--fg)}
.lesson-hero-actions{margin-top:18px}
.lesson-hero-route{position:absolute;left:3%;bottom:28px;width:94%;max-height:110px;opacity:.32;pointer-events:none}
.lesson-hero-route--quiet{opacity:.18}
.lesson-hero-floral{position:absolute;bottom:0;left:0;width:100%;height:28px;object-fit:cover;background:var(--immersive-teal);border-top:1px solid var(--gold);pointer-events:none}
.lesson-framework-section{padding-block:36px 24px}
.lesson-framework-panel{padding:28px 32px}
.lesson-brief-heading{display:grid;grid-template-columns:minmax(0,.7fr) minmax(0,1.3fr);gap:32px;padding-bottom:24px;margin-bottom:24px;border-bottom:1px solid var(--gold);align-items:start}
.lesson-brief-heading h2{font-size:32px;line-height:1.2}
.lesson-brief-heading .eyebrow{margin-bottom:10px}
.essential-question{padding-left:20px;margin:0;border-left:2px solid var(--gold)}
.essential-question span{color:var(--muted);font-size:12px}
.essential-question p{margin:8px 0 0;color:var(--fg);font-family:var(--font-display);font-size:24px;line-height:1.4}
.lesson-brief-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px 40px}
.lesson-brief-grid article{border-top:1px solid var(--border);padding-top:16px}
.lesson-brief-grid .card-kicker{margin:0 0 8px;padding:0;border:0;color:var(--muted);font-size:12px;text-transform:none}
.lesson-brief-grid h3{font-size:23px;margin-bottom:12px}
.lesson-brief-grid .check-list{margin:0}
.lesson-brief-grid p:last-child{margin-bottom:0}
.lesson-preview-section{padding-block:0 24px}
.lesson-readiness{display:grid;grid-template-columns:64px minmax(0,1fr);gap:28px;align-items:center}
.lesson-readiness .eyebrow{margin-bottom:10px}
.lesson-readiness h2{font-size:28px;line-height:1.2}
.lesson-readiness p:last-of-type{max-width:88ch;margin:12px 0 0}
.lesson-readiness .btn{margin-top:16px}
.lesson-related{padding-block:12px 40px}
.lesson-related .other-lessons{margin-top:20px}
.lesson-preparation>h2{margin-bottom:20px}
.preview-stage{padding:16px;background:var(--bg);box-shadow:none}
.slide-preview{margin:0;padding:0;aspect-ratio:16/9}
.slide-preview img{width:100%;height:100%;object-fit:contain}
.preview-thumbnails{display:flex;gap:10px;overflow-x:auto;padding:12px 4px}
.preview-thumbnails button{flex:0 0 96px;padding:2px;border:1px solid var(--border);background:var(--surface)}
.preview-thumbnails button[aria-pressed="true"]{border:2px solid var(--gold)}

/* Services, trust, and archive pages share the same dark reading system. */
.info-page .hero,.service-page .hero{background-image:linear-gradient(90deg,rgba(7,24,32,.9),rgba(7,24,32,.67)),url("/assets/immersive/home-hero-desktop.webp");background-size:cover;background-position:center 58%;border-bottom:1px solid var(--gold);padding-block:56px 60px}
.info-page .hero::before,.service-page .hero::before{display:none}
.info-page .hero h1,.service-page .hero h1{font-size:clamp(36px,4.2vw,56px)}
.info-page .hero .lead,.service-page .hero .lead{max-width:62ch}
.service-page .hero .lesson-status{margin-bottom:20px}
.service-page .hero .hero-cta{margin-top:24px}
.service-page .section-head h2{font-size:34px}
.service-page .section-head .lead{font-size:16px}
.service-tiers .card{padding:24px}
.service-tiers h3{font-size:26px}
.service-tiers .check-list{margin:18px 0}
.service-price-note{margin:16px 0 0;padding-top:16px;border-top:1px solid var(--border);color:var(--muted);font-size:14px}
.service-unavailable-note{margin:0 0 24px;padding:16px 20px;border:1px solid var(--gold);background:var(--surface-warm);color:var(--fg-2)}
.service-unavailable-note strong{display:block;color:var(--fg)}
.service-unavailable-note p{margin:8px 0 0}
.service-page .process-step{padding-block:20px}
.service-page #process h2,.service-page #brief-form h2,.service-page .faq-section h2{font-size:34px}
.service-page form{padding:28px}
.service-page form .grid-2{gap:20px}
.service-page form button[type=submit]{width:100%}
.service-page .accordion-trigger{font-size:21px;min-height:68px}
.service-page .accordion-panel{max-width:70ch}
.about-standards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.about-standards article{padding-top:20px;border-top:1px solid var(--gold)}
.about-standards h3{font-size:24px;margin-bottom:12px}
.about-standards p{color:var(--fg-2);margin:0}
.trust-promise{margin-top:28px;background:var(--surface);border-color:var(--border);border-left-color:var(--gold)}
.trust-promise h2{font-size:28px}
.trust-promise p{font-size:17px}
.index-page .hero,.editorial-page:not(.exhibition-page) .hero{background:var(--surface);border-bottom:1px solid var(--gold)}
.index-page .hero h1,.editorial-page .hero h1{font-size:clamp(36px,4vw,54px)}
.card{border-top-color:var(--gold);box-shadow:none}
.card::after{opacity:.1}
.search-box{padding:0 12px;background:var(--surface);border:1px solid var(--border)}
.filter-chip{min-height:44px;color:var(--fg)}
.filter-chip[aria-pressed="true"]{background:var(--accent);color:var(--bg)}
.lesson-status--paper{margin-bottom:14px;color:var(--accent)}
.topic-row--static,.log-row--static{cursor:default}
.toc{position:static;padding:20px;border:1px solid var(--border);background:var(--surface)}
.era-hanzi{color:var(--accent)}

/* The Silk Roads exhibition: a visual history journey that remains distinct from the teacher resource page. */
.exhibition-page{overflow-x:hidden;background:var(--bg)}
.exhibition-page .brand-nav.topnav{position:absolute;inset:0 0 auto;z-index:50;background-color:rgba(7,23,27,.3);background-image:none;border-bottom-color:rgba(228,196,122,.42)}
.exhibition-hero{position:relative;isolation:isolate;min-height:max(92svh,720px);display:flex;justify-content:center;overflow:hidden;background:var(--immersive-night);color:var(--immersive-text)}
.exhibition-hero-media,.exhibition-hero-media img,.exhibition-hero-veil,.exhibition-hero-texture{position:absolute;inset:0;width:100%;height:100%}
.exhibition-hero-media{z-index:-6}.exhibition-hero-media img{object-fit:cover;object-position:center center}
.exhibition-hero-veil{z-index:-5;background:rgba(3,15,18,.4);box-shadow:inset 0 -170px 150px rgba(2,12,15,.55),inset 0 100px 90px rgba(2,12,15,.32)}
.exhibition-hero-texture{z-index:-4;object-fit:cover;opacity:.2;mix-blend-mode:soft-light;pointer-events:none}
.exhibition-hero-route{position:absolute;z-index:0;left:4%;bottom:62px;width:92%;height:auto;opacity:.9;filter:drop-shadow(0 0 9px rgba(228,196,122,.32));pointer-events:none}
.exhibition-hero-copy{position:relative;z-index:2;display:flex;flex-direction:column;align-items:center;text-align:center;padding-top:clamp(142px,18vh,178px)}
.exhibition-kicker{margin:0 0 18px;color:var(--immersive-gold-highlight);font-family:var(--font-mono);font-size:12px;font-weight:700;letter-spacing:.2em;text-transform:uppercase;text-shadow:0 2px 12px rgba(0,0,0,.82)}
.exhibition-hero h1{max-width:none;margin:0;color:var(--immersive-text);font-size:clamp(66px,8vw,116px);font-weight:500;line-height:.88;letter-spacing:.09em;text-transform:uppercase;text-shadow:0 4px 26px rgba(0,0,0,.76)}
.exhibition-subtitle{margin:22px 0 0;color:var(--immersive-gold-highlight);font-family:var(--font-display);font-size:clamp(25px,2.6vw,38px);line-height:1.18;letter-spacing:.045em;text-shadow:0 2px 14px rgba(0,0,0,.78)}
.exhibition-summary{max-width:690px;margin:14px auto 0;color:rgba(240,228,203,.9);font-size:17px;line-height:1.55;text-shadow:0 2px 12px rgba(0,0,0,.82)}
.exhibition-actions{display:flex;align-items:center;justify-content:center;gap:24px;margin-top:25px}
.exhibition-note{margin:12px 0 0;color:rgba(240,228,203,.7);font-family:var(--font-mono);font-size:11px;letter-spacing:.05em}
.exhibition-hero-floral{position:absolute;z-index:3;left:0;bottom:0;width:100%;height:54px;object-fit:cover;object-position:center top;background:var(--immersive-teal);border-top:1px solid var(--immersive-gold);pointer-events:none}

.exhibition-index{position:sticky;top:0;z-index:25;background:var(--immersive-night);border-block:1px solid rgba(199,154,69,.52);color:var(--immersive-text)}
.exhibition-index .container{display:flex;justify-content:center;gap:clamp(18px,3.2vw,46px);overflow-x:auto;scrollbar-width:none;overscroll-behavior-inline:contain}
.exhibition-index .container::-webkit-scrollbar{display:none}
.exhibition-index a{flex:none;min-height:52px;display:inline-flex;align-items:center;color:rgba(240,228,203,.8);font-family:var(--font-mono);font-size:11px;font-weight:650;letter-spacing:.08em;text-transform:uppercase;border-bottom:2px solid transparent}
.exhibition-index a:hover,.exhibition-index a:focus-visible{color:var(--immersive-gold-highlight);border-bottom-color:var(--immersive-gold)}
.exhibition-section{scroll-margin-top:54px;background-color:var(--bg);background-image:linear-gradient(rgba(7,24,32,.96),rgba(7,24,32,.96)),url("/assets/immersive/fresco-texture.webp");background-size:auto,720px 720px}
.exhibition-section--tinted{background-color:var(--bg)}
.exhibition-section--ink{background-color:var(--fg);background-image:linear-gradient(rgba(11,52,50,.92),rgba(7,23,27,.96)),url("/assets/immersive/fresco-texture.webp");background-size:auto,640px 640px;color:var(--immersive-text)}
.exhibition-section--ink h2,.exhibition-section--ink h3{color:var(--immersive-text)}
.exhibition-section--ink .eyebrow{color:var(--immersive-gold-highlight)}
.exhibition-section--ink p{color:rgba(240,228,203,.78)}
.exhibition-section h2{max-width:18ch;color:var(--fg)}
.exhibition-split{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(300px,.65fr);gap:clamp(40px,8vw,104px);align-items:start}
.exhibition-prose>p:not(.eyebrow):not(.exhibition-lede){max-width:66ch;color:var(--fg-2)}
.exhibition-lede{max-width:54ch;color:var(--fg);font-family:var(--font-display);font-size:clamp(22px,2.2vw,30px);line-height:1.4}
.exhibition-prose h2{margin-bottom:var(--space-6)}
.exhibition-facts{border-block:3px double var(--immersive-teal)}
.exhibition-facts div{padding:20px 4px;border-bottom:1px solid color-mix(in oklab,var(--immersive-gold) 55%,var(--border))}
.exhibition-facts div:last-child{border-bottom:0}
.exhibition-facts span{display:block;color:var(--accent);font-family:var(--font-mono);font-size:11px;font-weight:700;letter-spacing:.1em;text-transform:uppercase}
.exhibition-facts strong{display:block;margin-top:4px;color:var(--fg);font-family:var(--font-display);font-size:24px;font-weight:500}
.route-story{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);gap:clamp(40px,7vw,88px);align-items:center}
.route-map{position:relative;margin:0;padding:18px;border:1px solid var(--immersive-gold);background:color-mix(in oklab,var(--immersive-teal) 7%,var(--surface));box-shadow:0 22px 48px rgba(32,25,20,.14),inset 0 0 0 5px var(--surface)}
.route-map::after{content:"";position:absolute;inset:8px;border:1px solid color-mix(in oklab,var(--immersive-gold) 45%,transparent);pointer-events:none}
.route-map img{width:100%;height:auto;filter:sepia(.1) saturate(.82) contrast(1.06)}
.route-map figcaption{padding-top:13px;color:var(--muted);font-family:var(--font-mono);font-size:11px;letter-spacing:.03em}
.route-reading{margin-top:var(--space-6);padding:var(--space-5);border-left:3px solid var(--immersive-gold);background:var(--surface)}
.route-reading span{color:var(--accent);font-family:var(--font-mono);font-size:11px;font-weight:700;letter-spacing:.1em;text-transform:uppercase}
.route-reading p{margin:6px 0 0;color:var(--fg);font-family:var(--font-display);font-size:20px;line-height:1.4}
.exhibition-narrow{width:min(100%,920px)}
.exhibition-narrow>h2{max-width:19ch;margin-bottom:var(--space-12)}
.exhibition-timeline{border-left-color:var(--immersive-gold)}
.exhibition-timeline .timeline-item{grid-template-columns:160px 1fr;padding-bottom:40px}
.exhibition-timeline .timeline-item::before{background:var(--immersive-brown)}
.exhibition-timeline .timeline-item h3{color:var(--fg);font-size:25px}
.exhibition-timeline .timeline-item time{color:var(--accent);font-weight:700}
.exhibition-section-heading{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(280px,.75fr);gap:var(--space-12);align-items:end;margin-bottom:var(--space-12);padding-bottom:var(--space-6);border-bottom:1px solid var(--immersive-gold)}
.exhibition-section-heading>p{max-width:42ch;margin:0;color:var(--fg-2)}
.exchange-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:var(--space-8)}
.exchange-grid article{padding:var(--space-6);border:1px solid rgba(199,154,69,.58);border-top:3px solid var(--immersive-gold);background:rgba(7,23,27,.34)}
.exchange-grid article>span{color:var(--immersive-gold-highlight);font-family:var(--font-mono);font-size:12px;letter-spacing:.1em}
.exchange-grid h3{margin:12px 0;font-size:26px}
.people-places-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:var(--space-5)}
.people-places-grid article{padding:var(--space-6) 0;border-top:2px solid var(--immersive-gold)}
.people-places-grid h3{margin:8px 0 12px;color:var(--fg);font-size:25px}
.people-places-grid p:last-child{color:var(--fg-2);font-size:15px}
.evidence-layout{display:grid;grid-template-columns:minmax(0,1fr) minmax(360px,.8fr);gap:clamp(40px,8vw,96px);align-items:center}
.evidence-questions{list-style:none;margin:0;padding:0;border-top:3px double var(--immersive-teal)}
.evidence-questions li{display:grid;grid-template-columns:48px 1fr;gap:var(--space-4);align-items:start;padding:var(--space-5) 0;border-bottom:1px solid color-mix(in oklab,var(--immersive-gold) 62%,var(--border))}
.evidence-questions span{color:var(--accent);font-family:var(--font-mono);font-size:12px}
.evidence-questions p{margin:0;color:var(--fg);font-family:var(--font-display);font-size:20px;line-height:1.4}
.exhibition-visuals{background-color:var(--immersive-night);background-image:linear-gradient(rgba(7,23,27,.92),rgba(7,23,27,.98)),url("/assets/immersive/fresco-texture.webp");background-size:auto,640px 640px;color:var(--immersive-text)}
.exhibition-visuals h2,.exhibition-visuals h3{color:var(--immersive-text)}
.exhibition-visuals .eyebrow{color:var(--immersive-gold-highlight)}
.exhibition-visuals .exhibition-section-heading>p{color:rgba(240,228,203,.74)}
.exhibition-card-track{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:14px}
.exhibition-card{min-width:0;display:flex;flex-direction:column;border:1px solid rgba(199,154,69,.58);background:var(--immersive-teal);box-shadow:0 16px 32px rgba(0,0,0,.28);transition:transform var(--motion-base) var(--ease-standard),border-color var(--motion-base) var(--ease-standard),box-shadow var(--motion-base) var(--ease-standard)}
.exhibition-card-art{position:relative;overflow:hidden;aspect-ratio:4/5;background:var(--immersive-night)}
.exhibition-card-art>img:first-child{width:100%;height:100%;object-fit:cover;transition:transform 900ms var(--ease-standard)}
.exhibition-card-frame{position:absolute;inset:0;width:100%;height:100%;object-fit:fill;pointer-events:none}
.exhibition-card-label{flex:1;padding:18px 16px 20px;border-top:1px solid rgba(199,154,69,.5)}
.exhibition-card-label span{display:block;color:var(--immersive-gold-highlight);font-family:var(--font-mono);font-size:10px;font-weight:650;letter-spacing:.08em;text-transform:uppercase}
.exhibition-card-label h3{margin:7px 0 8px;font-size:21px;line-height:1.12}
.exhibition-card-label p{margin:0;color:rgba(240,228,203,.76);font-size:14px;line-height:1.48}
.exhibition-card:hover{transform:translateY(-5px);border-color:var(--immersive-gold-highlight);box-shadow:0 22px 38px rgba(0,0,0,.38),0 0 16px rgba(199,154,69,.16)}
.exhibition-card:hover .exhibition-card-art>img:first-child{transform:scale(1.035)}
.exhibition-card:focus-visible{outline:2px solid var(--immersive-gold-highlight);outline-offset:4px;box-shadow:none}
.classroom-connection{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(320px,.65fr);gap:clamp(40px,8vw,96px);align-items:start}
.exhibition-actions--light{justify-content:flex-start}
.teacher-lesson-panel{padding:var(--space-8);border:1px solid var(--immersive-gold);border-top:4px solid var(--immersive-teal);background:var(--surface);box-shadow:0 18px 38px rgba(32,25,20,.1)}
.teacher-lesson-panel h3{margin:8px 0;color:var(--fg);font-size:28px}
.teacher-lesson-panel .check-list{margin-block:var(--space-5)}
.exhibition-connected-heading{margin-bottom:var(--space-8)}

@media(max-width:1023px){
  .exhibition-page .brand-nav.topnav{background-color:rgba(7,23,27,.62)}
  .exhibition-section-heading,.exhibition-split,.route-story,.evidence-layout,.classroom-connection{grid-template-columns:1fr}
  .exhibition-section-heading{align-items:start}
  .people-places-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .exhibition-card-track{display:flex;gap:14px;overflow-x:auto;padding:6px 4px 18px;scroll-snap-type:x mandatory;scroll-padding-inline:4px;scrollbar-width:none;overscroll-behavior-inline:contain}
  .exhibition-card-track::-webkit-scrollbar{display:none}
  .exhibition-card{flex:0 0 min(40vw,300px);scroll-snap-align:start}
}

@media(max-width:639px){
  .exhibition-hero{min-height:max(100svh,790px)}
  .exhibition-hero-media img{object-position:center center}
  .exhibition-hero-veil{background:rgba(3,15,18,.5);box-shadow:inset 0 -140px 115px rgba(2,12,15,.58),inset 0 80px 64px rgba(2,12,15,.3)}
  .exhibition-hero-texture{opacity:.16}
  .exhibition-hero-copy{padding:116px 18px 96px}
  .exhibition-kicker{margin-bottom:14px;font-size:10px;letter-spacing:.15em}
  .exhibition-hero h1{max-width:350px;font-size:clamp(48px,14.5vw,60px);line-height:.9;letter-spacing:.055em}
  .exhibition-subtitle{max-width:330px;margin-top:17px;font-size:24px;line-height:1.2}
  .exhibition-summary{max-width:340px;margin-top:11px;font-size:14px;line-height:1.45}
  .exhibition-actions{width:100%;flex-direction:column;gap:6px;margin-top:18px}
  .exhibition-actions .immersive-button{min-height:48px}
  .exhibition-actions .immersive-text-link{min-height:44px}
  .exhibition-note{margin-top:8px;font-size:11px}
  .exhibition-hero-route{left:-22%;bottom:48px;width:144%;opacity:.6}
  .exhibition-hero-floral{height:42px}
  .exhibition-index .container{justify-content:flex-start;padding-inline:16px;scroll-padding-inline:16px}
  .exhibition-index a{min-height:48px}
  .exhibition-section{scroll-margin-top:50px}
  .exhibition-section-heading{gap:var(--space-5);margin-bottom:var(--space-8)}
  .exhibition-lede{font-size:22px}
  .exhibition-facts strong{font-size:22px}
  .route-map{padding:12px}
  .route-reading{padding:var(--space-4)}
  .exhibition-narrow>h2{margin-bottom:var(--space-8)}
  .exhibition-timeline .timeline-item{grid-template-columns:1fr;gap:8px;padding-left:24px;padding-bottom:30px}
  .exhibition-timeline .timeline-item h3{font-size:23px}
  .exchange-grid,.people-places-grid{grid-template-columns:1fr}
  .exchange-grid{gap:var(--space-5)}
  .exchange-grid article{padding:var(--space-5)}
  .evidence-questions li{grid-template-columns:40px 1fr}
  .evidence-questions p{font-size:19px}
  .exhibition-card-track{margin-inline:-16px;padding:6px 16px 18px;scroll-padding-inline:16px}
  .exhibition-card{flex:0 0 min(76vw,304px)}
  .exhibition-card-label{padding:17px 16px 19px}
  .teacher-lesson-panel{padding:var(--space-5)}
  .exhibition-actions--light{align-items:stretch}.exhibition-actions--light .btn{width:100%}
  .exhibition-connected-heading{align-items:flex-start}
}

@media(hover:none){
  .exhibition-card:active{border-color:var(--immersive-gold-highlight);box-shadow:0 14px 30px rgba(0,0,0,.35)}
}



/* Content-driven reflow. Medium widths use two course columns, narrow widths one. */
@media(max-width:1100px){
  .topnav-inner{grid-template-columns:1fr auto;min-height:72px}
  .home-rosette,.nav-rosette{position:absolute;grid-column:1/-1;grid-row:1;left:50%;transform:translateX(-50%);width:54px;height:54px}
  .logo{z-index:1;font-size:18px}
  .menu-toggle{display:flex;grid-column:2;grid-row:1;z-index:1}
  .topnav nav{display:none;position:absolute;top:100%;left:24px;right:24px;grid-column:auto;width:auto;max-height:calc(100svh - 80px);overflow-y:auto;flex-direction:column;align-items:stretch;gap:0;padding:8px 18px;background:var(--bg);border:1px solid var(--gold);box-shadow:0 12px 24px rgba(0,0,0,.4)}
  .topnav nav.is-open{display:flex}.topnav nav a{min-height:48px;border-bottom:1px solid var(--border)}
  .home-custom-panel{grid-template-columns:1fr;gap:20px}
  .home-custom-panel .btn{justify-self:start}
  .container{padding-inline:24px}
  .grid-4,.people-places-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .dynasty-track{grid-template-columns:repeat(3,minmax(0,1fr))}
  .hero-split,.grid-1-2,.grid-2-1{grid-template-columns:1fr}
  .service-tiers{grid-template-columns:1fr}
  .foot-grid{grid-template-columns:1fr}.foot-links{justify-content:flex-start}
}
@media(max-width:760px){
  .section-head,.lesson-brief-heading{grid-template-columns:1fr;gap:20px}
  .lesson-brief-grid,.about-standards,.grid-3,.person-list{grid-template-columns:1fr}
  .topnav .logo small{display:none}
  .topnav .logo{font-size:0;width:44px;padding-left:44px}
  .immersive-home-copy{padding-block:112px 150px}
  .immersive-home h1{font-size:clamp(38px,8vw,58px)}
  .immersive-actions{gap:12px}
  .lesson-hero-content{padding-block:84px 62px}
  .lesson-hero h1{max-width:18ch}
  .lesson-hero-summary{font-size:16px}
}
@media(max-width:639px){
  .container{padding-inline:16px}
  .section{padding-block:40px}
  .topnav-inner{gap:12px;min-height:70px}
  .topnav nav{left:16px;right:16px}
  .home-rosette,.nav-rosette{width:48px;height:48px}
  .immersive-home-copy{justify-content:flex-start;padding-block:106px 140px}
  .immersive-home h1{font-size:clamp(36px,10.4vw,49px);letter-spacing:.02em;line-height:1.02}
  .immersive-kicker{font-size:11px;margin-bottom:14px}
  .immersive-subtitle{margin-top:20px;font-size:23px}
  .immersive-summary{font-size:16px;margin-top:16px}
  .immersive-actions{flex-direction:column;gap:12px;width:100%;margin-top:24px}
  .immersive-button{width:100%;padding:13px 16px}
  .immersive-home-route{left:0;width:100%;bottom:30px;opacity:.6}
  .immersive-home-floral{height:30px}.home-hero-caption{display:none}
  .museum-section-heading{margin-bottom:22px;padding-bottom:18px}
  .museum-section-heading h2{font-size:30px}
  .home-custom-band{padding-bottom:32px}
  .museum-panel,.home-custom-panel,.lesson-framework-panel{padding:24px 20px}
  .home-custom-panel .btn{width:100%}
  .home-custom-panel h2{font-size:28px}
  .lesson-hero h1{font-size:40px;line-height:1.08}
  .lesson-status--hero{margin-top:20px}
  .lesson-hero-deck{font-size:22px}
  .lesson-hero-meta{grid-template-columns:repeat(2,minmax(0,1fr))}
  .lesson-hero-meta div{padding:10px 8px}
  .lesson-hero-meta div:nth-child(3){grid-column:1/-1;border-left:0;border-top:1px solid var(--border)}
  .lesson-curriculum{font-size:14px}
  .lesson-hero-actions{width:100%}
  .lesson-hero-actions [data-lesson-download]{width:100%}
  .lesson-hero-actions .btn{width:100%}
  .lesson-hero-route{left:0;width:100%;bottom:26px}
  .lesson-framework-section{padding-top:28px}
  .lesson-brief-heading h2{font-size:29px}
  .essential-question{padding-left:16px}
  .essential-question p{font-size:22px}
  .lesson-brief-grid{gap:24px}
  .lesson-readiness{grid-template-columns:1fr;gap:16px}
  .lesson-readiness>img{width:48px;height:48px}
  .lesson-readiness h2{font-size:27px}
  .other-lessons{flex-direction:column;align-items:stretch}
  .gold-divider{text-align:center}
  .grid-2,.grid-4{grid-template-columns:1fr}
  .row-between{align-items:flex-start;flex-direction:column}
  .hero-cta{flex-direction:column;align-items:stretch}
  .hero-cta .btn{width:100%}
  .info-page .hero,.service-page .hero{padding-block:40px;background-image:linear-gradient(rgba(7,24,32,.82),rgba(7,24,32,.88)),url("/assets/immersive/home-hero-mobile.webp");background-position:center 38%}
  .info-page .hero h1,.service-page .hero h1{font-size:36px}
  .lead{font-size:18px}.trust-promise{padding:20px}
  .service-page form{padding:24px 18px}
  .process-step{grid-template-columns:36px 1fr;gap:16px}
  .process-step h3{font-size:24px}
  .topic-row,.log-row{grid-template-columns:1fr;gap:8px}
  .timeline-item{grid-template-columns:1fr;gap:8px;padding-left:24px}
  .dynasty-track{grid-template-columns:repeat(2,minmax(0,1fr))}
  .fact-box{grid-template-columns:1fr}
  .pull{text-align:left}
  .article{max-width:100%}.article h2{font-size:30px}
  .foot-note{flex-direction:column;gap:8px}
  .foot-links{gap:12px 24px}
  .btn{font-size:14px}
}
@media(max-height:800px) and (min-width:761px){
  .immersive-home-copy{padding-block:110px 116px}
  .immersive-home h1{font-size:clamp(46px,6vw,78px)}
  .immersive-subtitle{margin-top:20px}
  .immersive-summary{margin-top:12px}
  .immersive-actions{margin-top:20px}
}
@media(hover:hover){
  .home-lesson-collection .lesson-card:hover{transform:translateY(-3px);border-color:var(--accent)}
}
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{scroll-behavior:auto!important;animation:none!important;transition:none!important}
}

/* Silk Roads v4 release: document colors stay intact inside the museum shell. */
.silk-roads-release .lesson-hero-content{padding-block:100px 62px}
.silk-roads-release .lesson-hero h1{font-size:clamp(38px,4.2vw,60px);line-height:1.1}
.silk-roads-release .lesson-hero-deck{max-width:45ch;font-size:clamp(20px,2vw,26px);line-height:1.4}
.silk-roads-release .lesson-hero-meta{width:min(100%,650px);margin-top:18px}
.silk-roads-release .lesson-status--hero{text-transform:uppercase;letter-spacing:.12em}
.silk-roads-release .lesson-hero-actions{gap:12px;margin-top:18px}
.silk-roads-release .release-note{margin:12px 0 0;font-size:14px;line-height:1.6;color:var(--fg-2)}
.silk-roads-release #lesson-preview,.silk-roads-release #lesson-framework{scroll-margin-top:16px}
.silk-roads-release .material-preview-section{padding-block:32px 24px}
.silk-roads-release .release-section-heading{display:flex;justify-content:space-between;align-items:baseline;gap:12px 32px;margin-bottom:20px}
.silk-roads-release .release-section-heading h2{font-size:clamp(28px,3vw,38px);line-height:1.2}
.silk-roads-release .release-section-heading p{margin:0;max-width:42ch;font-size:14px;color:var(--fg-2)}
.silk-roads-release .material-preview-grid{display:grid;grid-template-columns:minmax(0,2.25fr) minmax(260px,1fr);gap:24px;align-items:start}
.silk-roads-release .material-browser{min-width:0;border:1px solid var(--border);border-radius:2px;background:rgba(12,41,43,.75)}
.silk-roads-release .material-tabs{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border-bottom:1px solid var(--gold)}
.silk-roads-release .material-tabs button{min-height:50px;padding:10px 6px;background:transparent;color:var(--fg);font:600 13px/1.5 var(--font-body);border:0;border-right:1px solid var(--border);cursor:pointer}
.silk-roads-release .material-tabs button:last-child{border-right:0}
.silk-roads-release .material-tabs button[aria-selected="true"]{background:var(--surface-warm);color:var(--accent);box-shadow:inset 0 -3px var(--accent)}
.silk-roads-release #material-panel{padding:16px}
.silk-roads-release .material-title{margin:0 0 10px;color:var(--fg-2);font-size:13px;line-height:1.4}
.silk-roads-release .material-stage{margin:0;min-width:0;display:flex;justify-content:center;position:relative;aspect-ratio:16/9;background:var(--bg)}
.silk-roads-release .material-stage[data-format="portrait"]{aspect-ratio:1530/1980;max-width:570px;margin-inline:auto}
.silk-roads-release .material-stage img{display:block;width:100%;height:auto;object-fit:contain;align-self:flex-start}
.silk-roads-release .material-loading{position:absolute;z-index:2;left:50%;top:12px;transform:translateX(-50%);max-width:calc(100% - 24px);padding:8px 14px;border:1px solid var(--gold);background:#0b252c;color:var(--fg);font:600 13px/1.5 var(--font-body);text-align:center;pointer-events:none;box-shadow:0 2px 8px #0006}
.silk-roads-release .reader-loading{top:78px}
.silk-roads-release .material-thumbs{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:8px;margin-top:12px}
.silk-roads-release .material-thumbs button{min-width:0;min-height:44px;padding:3px;background:var(--bg);border:1px solid var(--border);color:var(--fg-2);cursor:pointer;font:12px var(--font-body)}
.silk-roads-release .material-thumbs img{width:100%;height:55px;object-fit:contain;display:block;margin-bottom:3px}
.silk-roads-release .material-thumbs button[aria-pressed="true"]{border-color:var(--accent);box-shadow:inset 0 0 0 1px var(--accent);color:var(--accent)}
.silk-roads-release .material-controls{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px;padding-top:14px;margin-top:12px;border-top:1px solid var(--border)}
.silk-roads-release .material-controls .btn,.silk-roads-release .reader-controls .btn,.silk-roads-release .reader-header .btn{min-height:44px;padding:8px 10px;box-shadow:none;border-radius:2px;font-size:13px;gap:6px}
.silk-roads-release .page-picker{flex:1;min-width:122px;max-width:170px}
.silk-roads-release .page-picker select{width:100%;min-height:44px;padding:8px 24px 8px 8px;margin:0;background-color:var(--bg);color:var(--fg);border:1px solid var(--border);font-size:13px}
.silk-roads-release .material-pack-summary{padding:26px 24px;border:1px solid var(--gold);background:var(--surface);border-radius:2px}
.silk-roads-release .material-pack-summary .eyebrow{font-size:10px;line-height:1.5;letter-spacing:.08em}
.silk-roads-release .material-pack-summary h3{font-size:30px;line-height:1.2}
.silk-roads-release .material-pack-summary>p{font-size:14px;color:var(--fg-2)}
.silk-roads-release .material-pack-summary ul{list-style:none;padding:10px 0 20px;margin:18px 0 22px;border-block:1px solid var(--border)}
.silk-roads-release .material-pack-summary li{position:relative;padding:11px 0 0 18px;font-size:15px;color:var(--fg)}
.silk-roads-release .material-pack-summary li::before{content:"";position:absolute;left:0;top:21px;width:5px;height:5px;border:1px solid var(--gold)}
.silk-roads-release .material-pack-summary .btn{width:100%;padding-inline:10px;font-size:15px}
.silk-roads-release .release-files-section{padding-block:24px 32px}
.silk-roads-release .release-file-list{border:1px solid var(--border);background:rgba(12,41,43,.75)}
.silk-roads-release .release-file-row{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(130px,.7fr) auto;gap:16px;align-items:center;padding:12px 20px}
.silk-roads-release .release-file-row+.release-file-row{border-top:1px solid var(--border)}
.silk-roads-release .release-file-row h3{font-size:19px;line-height:1.4}
.silk-roads-release .release-file-row p{margin:0;font-size:14px;color:var(--fg-2)}
.silk-roads-release .release-file-actions{display:flex;gap:14px}
.silk-roads-release .release-file-actions a{display:flex;align-items:center;justify-content:center;min-height:44px;min-width:44px;font-size:13px}
.silk-roads-release .release-teaching-section{padding-block:20px 24px}
.silk-roads-release .release-teaching-section>.museum-panel{padding:28px 32px;width:calc(100% - 64px)}
.silk-roads-release .release-teaching-section h2{font-size:clamp(28px,3vw,36px)}
.silk-roads-release .release-teaching-section p{color:var(--fg-2);font-size:15px;line-height:1.7}
.silk-roads-release .release-core-map{padding-bottom:20px;border-bottom:1px solid var(--border)}
.silk-roads-release .release-teaching-grid{display:grid;grid-template-columns:1fr 1fr;gap:32px}
.silk-roads-release .release-teaching-grid h3{font-size:23px}
.silk-roads-release .material-image-error{align-self:center;margin:auto;padding:20px;color:var(--fg);background:var(--surface);text-align:center}
.silk-roads-release .material-image-error button{color:var(--accent);background:transparent;border:1px solid var(--border);min-height:44px;padding:8px;cursor:pointer}
.silk-roads-release .btn:disabled{opacity:.42;cursor:default;pointer-events:none}
.silk-roads-release .material-reader{position:fixed;inset:0;width:100%;max-width:none;height:100dvh;max-height:none;padding:0;margin:0;border:0;background:#06151c;color:var(--fg);overflow:hidden}
.silk-roads-release .material-reader[open]{display:flex;flex-direction:column}
.silk-roads-release .material-reader::backdrop{background:rgba(0,0,0,.88)}
.silk-roads-release .reader-header{display:flex;align-items:center;gap:16px;padding:12px max(16px,env(safe-area-inset-right)) 12px max(16px,env(safe-area-inset-left));border-bottom:1px solid var(--gold);flex-shrink:0}
.silk-roads-release .reader-header h2{flex:1;margin:0;font:600 18px/1.4 var(--font-body);text-align:center}
.silk-roads-release .reader-header>span{font-size:14px;white-space:nowrap}
.silk-roads-release .reader-viewport{flex:1;min-height:0;overflow:auto;overscroll-behavior:contain;scroll-behavior:auto;touch-action:pan-x pan-y pinch-zoom}
.silk-roads-release .reader-canvas{width:max-content;min-width:100%;min-height:100%;display:flex;align-items:center;justify-content:center;padding:12px}
.silk-roads-release .reader-canvas img{display:block;max-width:none;height:auto;flex-shrink:0;box-shadow:0 3px 18px rgba(0,0,0,.35)}
.silk-roads-release .reader-controls{display:flex;justify-content:center;align-items:center;gap:16px;flex-shrink:0;padding:12px 16px max(12px,env(safe-area-inset-bottom));border-top:1px solid var(--gold);background:var(--bg)}
.silk-roads-release .reader-zoom{display:flex;align-items:center;gap:8px}
.silk-roads-release .reader-zoom output{min-width:42px;font-size:12px;text-align:center}
.silk-roads-release .reader-zoom button{min-width:44px;font-size:20px}
.silk-roads-release .mobile-pack-bar{position:fixed;z-index:40;left:0;right:0;bottom:0;display:flex;align-items:center;gap:16px;padding:10px 16px max(10px,env(safe-area-inset-bottom));background:var(--surface);border-top:1px solid var(--gold);box-shadow:0 -4px 20px rgba(0,0,0,.3)}
.silk-roads-release .mobile-pack-bar>span{font-size:13px;white-space:nowrap}
.silk-roads-release .mobile-pack-bar>div{flex:1}
.silk-roads-release .mobile-pack-bar .btn{width:100%;min-height:48px;font-size:14px;padding:10px 8px}
.silk-roads-release [hidden]{display:none!important}
@media(max-width:999px){
  .silk-roads-release .material-preview-grid{grid-template-columns:1fr}
  .silk-roads-release .material-pack-summary{display:none}
  .silk-roads-release .release-section-heading{display:block}
  .silk-roads-release .release-section-heading p{margin-top:8px;max-width:none}
}
@media(max-width:767px){
  .silk-roads-release.has-mobile-pack-bar{padding-bottom:calc(84px + env(safe-area-inset-bottom))}
  .silk-roads-release .lesson-hero-content{padding-block:82px 56px}
  .silk-roads-release .lesson-hero-deck{max-width:32ch;font-size:21px}
  .silk-roads-release .lesson-hero-meta{display:flex;justify-content:center;flex-wrap:wrap;border:0;gap:0 12px}
  .silk-roads-release .lesson-hero-meta div,.silk-roads-release .lesson-hero-meta div:nth-child(3){padding:4px 0;border:0}
  .silk-roads-release .lesson-hero-meta dt{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}
  .silk-roads-release .lesson-hero-meta dd{font-size:14px;margin:0}
  .silk-roads-release .lesson-hero-meta div+div dd::before{content:"·";margin-right:12px;color:var(--accent)}
  .silk-roads-release .lesson-hero-actions{flex-direction:column;width:100%;max-width:420px}
  .silk-roads-release .lesson-hero-actions>*,.silk-roads-release .lesson-hero-actions .btn{width:100%}
  .silk-roads-release .material-tabs{grid-template-columns:1fr 1fr}
  .silk-roads-release .material-tabs button{border:1px solid var(--border);min-height:44px}
  .silk-roads-release #material-panel{padding:10px}
  .silk-roads-release .material-thumbs{gap:5px}
  .silk-roads-release .material-thumbs img{height:42px}
  .silk-roads-release .material-controls{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:8px}
  .silk-roads-release .control-word{display:none}
  .silk-roads-release .page-picker{max-width:none;min-width:0;grid-column:span 4}
  .silk-roads-release [data-reader-open],.silk-roads-release [data-preview-pdf]{grid-column:span 3}
  .silk-roads-release .material-controls:has([data-preview-prev][hidden]){grid-template-columns:1fr 1fr}
  .silk-roads-release .material-controls:has([data-preview-prev][hidden]) .page-picker{grid-column:1/-1}
  .silk-roads-release .material-controls:has([data-preview-prev][hidden]) [data-reader-open],.silk-roads-release .material-controls:has([data-preview-prev][hidden]) [data-preview-pdf]{grid-column:auto}
  .silk-roads-release .release-file-row{grid-template-columns:minmax(0,1fr) auto;gap:0 10px;padding:12px}
  .silk-roads-release .release-file-row h3{font-size:17px}
  .silk-roads-release .release-file-row p{grid-column:1;font-size:12px}
  .silk-roads-release .release-file-actions{grid-column:2;grid-row:1/3;gap:6px}
  .silk-roads-release .release-teaching-section>.museum-panel{width:calc(100% - 32px);padding:22px 20px}
  .silk-roads-release .release-teaching-grid{grid-template-columns:1fr;gap:16px}
  .silk-roads-release .reader-header{gap:10px;padding:10px 12px}
  .silk-roads-release .reader-header h2{font-size:14px}
  .silk-roads-release .reader-controls{gap:8px;flex-wrap:wrap;padding-inline:10px}
  .silk-roads-release .reader-controls [data-reader-pdf]{flex:1;min-width:90px}
  .silk-roads-release .reader-controls [data-reader-prev],.silk-roads-release .reader-controls [data-reader-next]{width:44px}
}

/* Great Wall release: readable tabs and a mural with a quiet central text area. */
body[data-lesson-page="great-wall"] .material-tabs{flex-wrap:wrap;overflow:visible}
body[data-lesson-page="great-wall"] .lesson-hero-media img{object-position:50% 50%}
body[data-lesson-page="great-wall"] .lesson-hero-veil{background:radial-gradient(ellipse at 50% 48%,rgba(3,15,18,.45),rgba(3,15,18,.12) 72%),linear-gradient(to bottom,rgba(3,15,18,.25),rgba(3,15,18,.16) 60%,rgba(7,24,32,.82));box-shadow:none}
body[data-lesson-page="great-wall"] .lesson-hero-texture{opacity:.06}
@media(min-width:640px) and (max-width:980px){body[data-lesson-page="great-wall"] .lesson-hero-media img{object-position:85% 50%}}
@media(max-width:639px){body[data-lesson-page="great-wall"] .lesson-hero-media img{object-position:50% 25%}body[data-lesson-page="great-wall"] .lesson-hero-veil{background:linear-gradient(to bottom,rgba(3,15,18,.32),rgba(3,15,18,.52) 35%,rgba(3,15,18,.48) 65%,rgba(7,24,32,.9))}}
body[data-lesson-page="great-wall"] .material-tabs{display:flex;flex-wrap:wrap}body[data-lesson-page="great-wall"] .material-tabs button{flex:1 1 140px;min-height:48px}

.home-lesson-collection .lesson-card__coming{display:block;padding:10px 12px;min-height:46px;border:1px solid var(--border);color:var(--fg-2);font-size:15px;line-height:1.5}

/* Chinese inventions v2: existing mural art, a longer title, seven readable tabs. */
.home-lesson-collection .lesson-card__subtitle{margin:-2px 0 7px;color:var(--fg-2);font-size:15px;line-height:1.35}
body[data-lesson-page="chinese-inventions"] .lesson-hero h1{max-width:24ch;font-size:clamp(36px,4vw,56px);line-height:1.12;text-wrap:balance}
body[data-lesson-page="chinese-inventions"] .lesson-hero-media img{object-position:50% 50%}
body[data-lesson-page="chinese-inventions"] .lesson-hero-veil{background:radial-gradient(ellipse at 50% 45%,rgba(3,15,18,.65),rgba(3,15,18,.2) 76%),linear-gradient(to bottom,rgba(3,15,18,.2),rgba(3,15,18,.24) 60%,rgba(7,24,32,.94));box-shadow:none}
body[data-lesson-page="chinese-inventions"] .lesson-hero-texture{opacity:.06}
body[data-lesson-page="chinese-inventions"] .material-tabs{display:flex;flex-wrap:wrap;overflow:visible}
body[data-lesson-page="chinese-inventions"] .material-tabs button{flex:1 1 140px;min-height:48px}
@media(max-width:639px){body[data-lesson-page="chinese-inventions"] .lesson-hero h1{font-size:36px;max-width:19ch}body[data-lesson-page="chinese-inventions"] .lesson-hero-media img{object-position:70% 50%}body[data-lesson-page="chinese-inventions"] .lesson-hero-veil{background:linear-gradient(to bottom,rgba(3,15,18,.45),rgba(3,15,18,.66) 35%,rgba(3,15,18,.57) 65%,rgba(7,24,32,.96))}}