:root {
  color-scheme: dark;
  --bg: #11100e;
  --bg-deep: #090908;
  --paper: #e9e1d3;
  --muted: #a49d91;
  --line: rgba(233,225,211,.18);
  --line-strong: rgba(233,225,211,.38);
  --copper: #d59a58;
  --copper-bright: #efb56f;
  --red: #a23828;
  --max: 1200px;
  --serif: Georgia, "Noto Serif SC", "Songti SC", serif;
  --sans: Inter, "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--paper); font: 16px/1.7 var(--sans); }
body::before { content: ""; position: fixed; inset: 0; pointer-events: none; opacity: .22; z-index: 20; background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.15'/%3E%3C/svg%3E"); }
a { color: inherit; }
button, input { font: inherit; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 100; background: var(--copper); color: #111; padding: .6rem 1rem; }
.skip-link:focus { top: 1rem; }

.site-header { width: min(calc(100% - 3rem), var(--max)); height: 84px; margin: auto; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); position: relative; z-index: 10; }
.brand { display: flex; align-items: center; gap: .8rem; text-decoration: none; font-size: .9rem; letter-spacing: .08em; }
.brand-mark { display: grid; place-items: center; width: 42px; height: 30px; border: 1px solid var(--copper); color: var(--copper-bright); font: 700 .7rem var(--sans); }
.site-nav { display: flex; gap: 2rem; }
.site-nav a { color: var(--muted); text-decoration: none; font-size: .84rem; transition: color .2s; }
.site-nav a:hover, .site-nav a:focus-visible { color: var(--paper); }
.nav-toggle { display: none; color: var(--paper); border: 1px solid var(--line-strong); background: transparent; padding: .4rem .7rem; }

main > section, footer { width: min(calc(100% - 3rem), var(--max)); margin-inline: auto; }
.hero { min-height: calc(100vh - 84px); display: grid; grid-template-columns: .9fr 1.1fr; align-items: center; gap: clamp(3rem, 7vw, 7rem); padding-block: 4rem; }
.eyebrow, .kicker { color: var(--copper-bright); font-size: .72rem; letter-spacing: .2em; text-transform: uppercase; }
.hero h1 { margin: 1.2rem 0 1.8rem; font: 400 clamp(3.8rem, 7.3vw, 7.3rem)/.94 var(--serif); letter-spacing: -.055em; }
.hero h1 em { color: var(--copper-bright); font-weight: 400; }
.lead { max-width: 32rem; color: #c9c1b5; font-size: 1.12rem; }
.hero-actions { display: flex; align-items: center; gap: 1.8rem; margin-top: 2.2rem; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: .65rem 1.15rem; text-decoration: none; }
.button.primary { background: var(--copper); color: #17110b; font-weight: 700; }
.button.primary:hover { background: var(--copper-bright); }
.text-link { text-underline-offset: .3rem; font-size: .9rem; }
.text-link span { color: var(--copper-bright); margin-left: .45rem; }
.hero-stats { display: grid; grid-template-columns: repeat(3,1fr); margin: 4rem 0 0; border-top: 1px solid var(--line); padding-top: 1rem; gap: 1rem; }
.hero-stats div { min-width: 0; }
.hero-stats dt { font: 400 1.3rem var(--serif); }
.hero-stats dd { margin: .25rem 0 0; color: var(--muted); font-size: .72rem; line-height: 1.45; }
.hero-visual { position: relative; margin: 0; }
.hero-visual::after { content: ""; position: absolute; inset: 0; background: linear-gradient(150deg, transparent 58%, rgba(0,0,0,.55)); pointer-events: none; }
.hero-visual img { width: 100%; aspect-ratio: 4/5; object-fit: cover; filter: grayscale(1) sepia(.18) contrast(1.08); display: block; }
.hero-visual figcaption { position: absolute; bottom: 1rem; left: 1rem; z-index: 1; font-size: .7rem; letter-spacing: .14em; text-transform: uppercase; }
.hero-visual figcaption span { color: var(--copper-bright); margin-right: .6rem; }
.frame-corner { position: absolute; z-index: 2; width: 44px; height: 44px; border-color: var(--copper-bright); border-style: solid; }
.frame-corner.tl { left: -10px; top: -10px; border-width: 1px 0 0 1px; }
.frame-corner.br { right: -10px; bottom: -10px; border-width: 0 1px 1px 0; }

.section-rule { border-top: 1px solid var(--line); }
.intro { display: grid; grid-template-columns: 1fr 1fr; gap: 8vw; padding-block: 7rem; }
.intro h2, .section-heading h2, .chooser h2 { margin: .8rem 0 0; font: 400 clamp(2.3rem, 4vw, 4.3rem)/1.08 var(--serif); letter-spacing: -.035em; }
.intro-copy { padding-top: 2rem; color: #bdb5a9; font-size: 1.04rem; }
.intro-copy p:first-child { color: var(--paper); }

.anatomy { padding-block: 7rem; }
.section-heading { max-width: 46rem; margin-bottom: 4rem; }
.section-heading > p:last-child { max-width: 37rem; color: var(--muted); }
.section-heading.compact { max-width: none; display: grid; grid-template-columns: .34fr 1fr; align-items: end; gap: 1rem; }
.section-heading.compact .kicker { grid-column: 1; }
.section-heading.compact h2 { grid-column: 2; }
.section-heading.compact > p:last-child:not(.kicker) { grid-column: 2; }
.anatomy-grid { display: grid; grid-template-columns: .9fr 1.1fr; border: 1px solid var(--line); min-height: 590px; }
.parts-list { list-style: none; padding: 0; margin: 0; border-right: 1px solid var(--line); }
.parts-list li:not(:last-child) { border-bottom: 1px solid var(--line); }
.parts-list button { width: 100%; min-height: 96px; display: grid; grid-template-columns: 2.8rem 1fr; grid-template-rows: auto auto; text-align: left; color: var(--paper); background: transparent; border: 0; padding: 1rem 1.2rem; cursor: pointer; transition: background .2s; }
.parts-list button:hover, .parts-list button.active { background: rgba(213,154,88,.11); }
.parts-list button > span { grid-row: 1/3; color: var(--copper-bright); font-size: .68rem; }
.parts-list strong { font: 400 1.1rem var(--serif); }
.parts-list small { color: var(--muted); font-size: .74rem; }
.camera-diagram { position: relative; display: flex; flex-direction: column; justify-content: space-between; overflow: hidden; min-height: 100%; padding: 2rem; background: repeating-linear-gradient(0deg,transparent 0,transparent 39px,rgba(233,225,211,.035) 40px), repeating-linear-gradient(90deg,transparent 0,transparent 39px,rgba(233,225,211,.035) 40px); }
.diagram-label { color: var(--copper-bright); font: 400 1.15rem var(--serif); }
.camera-diagram > p { margin: 0; color: var(--muted); font-size: .7rem; text-align: right; }
.camera-shape { position: relative; height: 270px; margin-inline: 5%; }
.rail { position: absolute; left: 3%; right: 3%; bottom: 28px; height: 9px; background: #9c9386; box-shadow: 0 16px 0 #4c4842; transition: .25s; }
.rear-standard, .front-standard { position: absolute; z-index: 2; bottom: 35px; width: 28px; height: 190px; border: 5px solid #8b8376; background: #2c2925; transition: .25s; }
.rear-standard { left: 8%; }
.front-standard { right: 10%; height: 165px; }
.rear-standard > span { position: absolute; inset: 7px -2px; border: 1px solid #c8bca8; background: rgba(191,215,211,.16); }
.front-standard > span { position: absolute; width: 70px; aspect-ratio: 1; border: 8px solid #34302b; border-radius: 50%; background: radial-gradient(circle,#0a0908 0 28%,#807568 30% 38%,#181614 40%); left: 50%; top: 45%; transform: translate(-50%,-50%); }
.bellows { position: absolute; z-index: 1; left: 13%; right: 14%; bottom: 74px; height: 128px; clip-path: polygon(0 6%,100% 19%,100% 87%,0 96%); background: repeating-linear-gradient(90deg,#25211e 0 12px,#5a4b3d 13px 18px,#171513 19px 27px); transition: .25s; }
.camera-shape [data-shape].highlight { filter: drop-shadow(0 0 9px var(--copper-bright)); border-color: var(--copper-bright); background-color: rgba(213,154,88,.35); }

.movements { padding-block: 7rem; }
.move-tabs { display: grid; grid-template-columns: repeat(4,1fr); border-bottom: 1px solid var(--line); margin-top: 3rem; }
.move-tabs button { background: transparent; border: 0; border-top: 1px solid transparent; color: var(--muted); padding: 1rem; cursor: pointer; }
.move-tabs button[aria-selected="true"] { color: var(--paper); border-color: var(--copper-bright); background: rgba(213,154,88,.08); }
.move-panel { display: grid; grid-template-columns: 1.2fr .8fr; min-height: 440px; border-bottom: 1px solid var(--line); }
.move-stage { display: grid; place-items: center; position: relative; overflow: hidden; background: #d7d0c4; color: #222; }
.move-stage::after { content: "焦平面控制示意"; position: absolute; left: 1rem; bottom: .8rem; font-size: .64rem; letter-spacing: .12em; }
.move-frame { position: absolute; left: 12%; bottom: 17%; width: 34%; height: 62%; border: 6px solid #26231f; transition: .45s cubic-bezier(.2,.8,.2,1); }
.move-axis { position: absolute; left: 50%; top: -26%; height: 150%; border-left: 1px dashed var(--red); }
.move-lens { position: absolute; right: -12px; top: 44%; width: 18px; height: 38px; background: #25221e; }
.building { position: absolute; right: 12%; bottom: 17%; width: 23%; height: 58%; border: 4px solid #34312c; display: grid; grid-template-columns: 1fr 1fr; gap: 12%; padding: 13%; transition: .45s; }
.building i { border: 2px solid #504a43; }
.move-stage[data-state="rise"] .move-frame { transform: translateY(-12%); }
.move-stage[data-state="shift"] .move-frame { transform: translateX(18%); }
.move-stage[data-state="tilt"] .move-frame { transform: rotate(-8deg); transform-origin: bottom center; }
.move-stage[data-state="swing"] .move-frame { transform: perspective(600px) rotateY(-23deg); }
.move-copy { display: flex; flex-direction: column; justify-content: center; padding: clamp(2rem,5vw,5rem); background: #171512; }
.move-copy h3 { font: 400 2rem/1.2 var(--serif); }
.move-copy > p:not(.move-index) { color: var(--muted); }
.move-index { color: var(--copper-bright); font-size: .68rem; letter-spacing: .2em; }
.move-note { border-top: 1px solid var(--line); padding-top: 1.2rem; font-size: .78rem; }

.sinar { padding-block: 7rem; }
.sinar-heading { display: grid; grid-template-columns: 1fr 1fr; gap: 8vw; align-items: end; margin-bottom: 4rem; }
.sinar-heading h2 { margin: .8rem 0 0; font: 400 clamp(2.3rem,4vw,4.3rem)/1.08 var(--serif); letter-spacing: -.035em; }
.sinar-intro { color: var(--muted); }
.sinar-intro p:first-child { color: var(--paper); }
.sinar-feature { display: grid; grid-template-columns: 1.35fr .65fr; min-height: 500px; border: 1px solid var(--line); }
.sinar-feature-image { position: relative; margin: 0; min-width: 0; overflow: hidden; background: #ccc3b6; }
.sinar-feature-image::after { content: ""; position: absolute; inset: 0; background: linear-gradient(160deg,transparent 50%,rgba(0,0,0,.62)); pointer-events: none; }
.sinar-feature-image img { width: 100%; height: 100%; object-fit: cover; display: block; filter: grayscale(.28) sepia(.1) contrast(1.05); }
.sinar-feature-image figcaption { position: absolute; z-index: 1; left: 1.2rem; bottom: 1rem; font-size: .72rem; letter-spacing: .1em; }
.sinar-feature-image figcaption span { color: var(--copper-bright); margin-right: .7rem; }
.sinar-feature-copy { display: flex; flex-direction: column; justify-content: center; padding: clamp(2rem,4vw,4rem); background: #171512; }
.model-code { color: var(--copper-bright); font-size: .68rem; letter-spacing: .17em; }
.sinar-feature-copy h3, .sinar-models h3 { margin: .55rem 0 1rem; font: 400 1.75rem/1.2 var(--serif); }
.sinar-feature-copy > p:not(.model-code), .sinar-models article > p:not(.model-code), .sinar-choice > p:not(.model-code) { color: var(--muted); }
.sinar-facts { margin: 1.4rem 0 0; border-top: 1px solid var(--line); }
.sinar-facts div { display: grid; grid-template-columns: 5.5rem 1fr; gap: 1rem; padding: .65rem 0; border-bottom: 1px solid var(--line); font-size: .74rem; }
.sinar-facts dt { color: var(--muted); }
.sinar-facts dd { margin: 0; }
.sinar-models { display: grid; grid-template-columns: 1fr 1fr .72fr; border-inline: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.sinar-models > * { min-width: 0; padding: 1.2rem; }
.sinar-models > *:not(:last-child) { border-right: 1px solid var(--line); }
.sinar-models figure { height: 290px; margin: 0 0 1.5rem; overflow: hidden; background: #d7d0c4; }
.sinar-models figure img { width: 100%; height: 100%; object-fit: cover; display: block; filter: grayscale(.82) sepia(.12) contrast(1.08); transition: filter .25s, transform .4s; }
.sinar-models article:hover figure img { filter: grayscale(.2) sepia(.08); transform: scale(1.015); }
.sinar-models ul { margin: 1.3rem 0 .4rem; padding: 1rem 0 0 1.2rem; border-top: 1px solid var(--line); color: #c8c0b4; font-size: .76rem; }
.sinar-choice { display: flex; flex-direction: column; justify-content: center; background: var(--paper); color: #1c1916; }
.sinar-choice .model-code { color: #855c2f; }
.sinar-choice > p:not(.model-code) { color: #645c53; }
.choice-rule { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: .6rem; margin-top: 2rem; color: #6d655c; font-size: .66rem; }
.choice-rule i { height: 1px; background: linear-gradient(90deg,#b48650,#302b26); }
.series-scale { display: flex; justify-content: space-between; margin-top: .5rem; font: 400 1rem var(--serif); }
.series-scale b:nth-child(2) { color: #8a5a25; }
.sinar-note { margin: 1.3rem 0 0; padding-left: 1rem; border-left: 2px solid var(--copper); color: var(--muted); font-size: .78rem; }

.formats { padding-block: 7rem; }
.format-cards { display: grid; grid-template-columns: repeat(3,1fr); gap: 1rem; margin-top: 4rem; }
.format-cards article { border: 1px solid var(--line); padding: 1.2rem; min-width: 0; }
.format-cards article > p:not(.tag) { color: var(--muted); min-height: 5.2rem; }
.format-cards h3 { margin: .3rem 0 1rem; font: 400 1.6rem var(--serif); }
.format-cards .tag { color: var(--copper-bright); font-size: .7rem; letter-spacing: .12em; margin: 1.3rem 0 0; }
.film { height: 210px; margin: 0 auto; border: 8px solid #24211e; outline: 1px solid #6f685f; background: radial-gradient(circle at 45% 35%,#dfc08e 0,#99714a 35%,#473326 68%,#1d1916); display: grid; place-items: center; color: rgba(255,255,255,.8); font: 400 1.1rem var(--serif); }
.film-45 { width: 168px; }
.film-57 { width: 150px; }
.film-810 { width: 168px; height: 210px; }
.format-cards dl { border-top: 1px solid var(--line); padding-top: .7rem; }
.format-cards dl div { display: flex; justify-content: space-between; gap: 1rem; font-size: .73rem; }
.format-cards dt { color: var(--muted); }
.format-cards dd { margin: 0; text-align: right; }
.fineprint { color: var(--muted); font-size: .72rem; }

.workflow { padding-block: 7rem; }
.timeline { list-style: none; margin: 4rem 0 0; padding: 0; display: grid; grid-template-columns: repeat(5,1fr); }
.timeline li { border-top: 1px solid var(--line-strong); padding: 1.2rem 1.2rem 1.2rem 0; position: relative; }
.timeline li::before { content: ""; position: absolute; width: 7px; height: 7px; border: 2px solid var(--copper-bright); border-radius: 50%; top: -5px; left: 0; background: var(--bg); }
.timeline span { color: var(--copper-bright); font-size: .68rem; }
.timeline h3 { margin: 1.5rem 0 .5rem; font: 400 1.15rem var(--serif); }
.timeline p { color: var(--muted); font-size: .78rem; }
.ritual { margin-top: 3rem; display: grid; grid-template-columns: 5rem 1fr; border: 1px solid var(--line); padding: 1rem; }
.ritual span { color: var(--copper-bright); font-size: .72rem; letter-spacing: .18em; }
.ritual p { margin: 0; }

.chooser { padding-block: 7rem; display: grid; grid-template-columns: .75fr 1.25fr; gap: 7vw; }
.chooser-copy > p:last-child { color: var(--muted); max-width: 30rem; }
.chooser-tool { border: 1px solid var(--line); padding: clamp(1.2rem,3vw,2.5rem); }
.chooser-tool fieldset { border: 0; padding: 0; margin: 0; }
.chooser-tool legend { font: 400 1.35rem var(--serif); margin-bottom: 1.2rem; }
.choice-grid { display: grid; grid-template-columns: 1fr 1fr; gap: .7rem; }
.choice-grid input { position: absolute; opacity: 0; }
.choice-grid span { display: flex; flex-direction: column; border: 1px solid var(--line); padding: .9rem 1rem; cursor: pointer; }
.choice-grid small { color: var(--muted); font-size: .72rem; }
.choice-grid input:checked + span { border-color: var(--copper-bright); background: rgba(213,154,88,.1); }
.choice-grid input:focus-visible + span { outline: 2px solid var(--paper); outline-offset: 2px; }
.recommendation { margin-top: 2rem; padding: 1.5rem; background: var(--paper); color: #1d1a17; }
.recommendation > p:first-child { margin: 0; color: #7c5a32; font-size: .68rem; letter-spacing: .16em; }
.recommendation h3 { margin: .6rem 0; font: 400 1.8rem var(--serif); }
.recommendation ul { padding-left: 1.1rem; }
.rec-reason { color: #5f584f; font-size: .86rem; }

.closing { padding-block: 8rem; text-align: center; }
.closing blockquote { margin: 2rem auto 3rem; font: 400 clamp(2rem,4vw,4.2rem)/1.2 var(--serif); }
footer { display: flex; justify-content: space-between; gap: 1rem; padding-block: 2rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .68rem; }
footer p { margin: 0; }

@media (max-width: 900px) {
  .site-header { height: 70px; }
  .nav-toggle { display: block; }
  .site-nav { display: none; position: absolute; left: 0; right: 0; top: 69px; flex-direction: column; gap: 0; background: #171512; border: 1px solid var(--line); }
  .site-nav.open { display: flex; }
  .site-nav a { padding: .9rem 1rem; border-bottom: 1px solid var(--line); }
  .hero { min-height: auto; grid-template-columns: 1fr; padding-block: 4rem 6rem; }
  .hero-visual { width: min(100%, 620px); justify-self: center; }
  .hero-visual img { aspect-ratio: 5/4; }
  .intro, .chooser { grid-template-columns: 1fr; gap: 2rem; }
  .anatomy-grid { grid-template-columns: 1fr; }
  .parts-list { border-right: 0; border-bottom: 1px solid var(--line); display: grid; grid-template-columns: 1fr 1fr; }
  .parts-list li { border-bottom: 1px solid var(--line); }
  .parts-list li:nth-child(odd) { border-right: 1px solid var(--line); }
  .camera-diagram { min-height: 480px; }
  .section-heading.compact { display: block; }
  .move-panel { grid-template-columns: 1fr; }
  .move-stage { min-height: 360px; }
  .sinar-heading, .sinar-feature { grid-template-columns: 1fr; }
  .sinar-feature-image { min-height: 420px; }
  .sinar-models { grid-template-columns: 1fr 1fr; }
  .sinar-models .sinar-choice { grid-column: 1 / -1; min-height: 300px; }
  .sinar-models > article:nth-child(2) { border-right: 0; }
  .sinar-models > .sinar-choice { border-top: 1px solid var(--line); }
  .format-cards { overflow-x: auto; grid-template-columns: repeat(3,minmax(270px,1fr)); scroll-snap-type: x mandatory; }
  .format-cards article { scroll-snap-align: start; }
  .timeline { grid-template-columns: 1fr; }
  .timeline li { border-top: 0; border-left: 1px solid var(--line-strong); padding: 0 0 2rem 2rem; }
  .timeline li::before { top: .2rem; left: -5px; }
  .timeline h3 { margin: .3rem 0; }
}

@media (max-width: 600px) {
  main > section, footer, .site-header { width: min(calc(100% - 2rem), var(--max)); }
  .hero h1 { font-size: clamp(3.4rem,18vw,5rem); }
  .hero-stats { grid-template-columns: 1fr; }
  .hero-stats div { display: grid; grid-template-columns: 4rem 1fr; align-items: baseline; }
  .intro, .anatomy, .movements, .sinar, .formats, .workflow, .chooser, .closing { padding-block: 5rem; }
  .parts-list { grid-template-columns: 1fr; }
  .parts-list li:nth-child(odd) { border-right: 0; }
  .parts-list button { min-height: 82px; }
  .camera-diagram { padding: 1rem; min-height: 390px; }
  .camera-shape { transform: scale(.82); transform-origin: center; margin-inline: -10%; }
  .move-tabs { grid-template-columns: 1fr 1fr; }
  .move-stage { min-height: 300px; }
  .sinar-feature-image { min-height: 300px; }
  .sinar-models { grid-template-columns: 1fr; }
  .sinar-models > *:not(:last-child) { border-right: 0; border-bottom: 1px solid var(--line); }
  .sinar-models .sinar-choice { grid-column: auto; }
  .sinar-models figure { height: 270px; }
  .choice-grid { grid-template-columns: 1fr; }
  .ritual { grid-template-columns: 1fr; gap: .5rem; }
  footer { flex-direction: column; }
}

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