:root{--ink:#1d1d1f;--muted:#86868b;--paper:#f5f5f7;--accent:#6366f1;--edge:clamp(24px,6.2vw,120px)}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:80px}body{margin:0;background:#fff;color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","PingFang SC","Helvetica Neue",sans-serif;-webkit-font-smoothing:antialiased}button,a{-webkit-tap-highlight-color:transparent}button,input{font:inherit}a{color:inherit;text-decoration:none}button{cursor:pointer}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #6366f1;outline-offset:6px}button{border:0}img,video{display:block;max-width:100%}h1,h2,h3,p{margin:0}h1,h2{letter-spacing:-.055em;font-weight:650;line-height:1.12}h2{font-size:clamp(46px,5.5vw,88px)}h2 span{color:var(--muted)}.eyebrow{font-size:19px;font-weight:600;letter-spacing:.02em;margin-bottom:25px}.nav{height:66px;padding:0 var(--edge);display:flex;align-items:center;justify-content:space-between;gap:30px;background:rgba(255,255,255,.85);backdrop-filter:blur(22px);position:sticky;top:0;z-index:40;border-bottom:1px solid #00000009}.logo img{width:84px;height:auto}.nav nav{display:flex;gap:34px;font-size:14px;font-weight:500}.pill{background:var(--ink);color:#fff;display:inline-flex;border-radius:40px;padding:15px 26px;align-items:center;justify-content:center;font-size:16px}.pill.small{font-size:13px;padding:9px 18px}.skip{position:fixed;left:20px;top:-60px;z-index:100;background:white;padding:14px}.skip:focus{top:10px}.hero{height:max(720px,calc(100svh - 66px));max-height:1100px;position:relative;overflow:hidden;background:#f7f7f7}.hero-art{position:absolute;inset:0}.hero-art img{height:100%;width:100%;object-fit:cover;object-position:50% 50%;transform:translateX(22%) scale(1.03)}.hero-art:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,#f8f8f8 0%,#f8f8f8ed 25%,#f8f8f835 55%,transparent 80%)}.hero-copy{position:absolute;left:var(--edge);top:17%;z-index:2}.hero h1{font-size:clamp(72px,7.5vw,128px);letter-spacing:-.075em}.hero-sub{font-size:clamp(20px,1.8vw,28px);line-height:1.55;color:#6e6e73;margin-top:32px}.text-button{background:none;padding:0;font-size:18px;color:var(--accent);margin-top:32px}.text-button span{margin-left:10px}.hero-bottom{position:absolute;left:var(--edge);right:var(--edge);bottom:35px;display:flex;justify-content:space-between;font-size:14px;color:#6e6e73;z-index:2}.hero-bottom a span{margin-left:20px}.manifesto{height:190vh;position:relative}.manifesto-sticky{height:100svh;position:sticky;top:0;overflow:hidden;display:grid;place-items:center}.manifesto-sticky>img{position:absolute;width:100%;height:100%;object-fit:cover;filter:blur(26px);opacity:.36;transform:scale(1.07)}.frost{position:absolute;inset:0;background:#ffffffe0;opacity:.7}.manifesto-copy{z-index:2;text-align:center;padding:40px 24px;max-width:1100px}.manifesto-copy p{font-size:clamp(27px,3.25vw,50px);font-weight:600;line-height:1.45;letter-spacing:-.035em;margin:42px 0;transition:opacity .3s,filter .3s}.section-intro{padding:120px var(--edge) 64px}.film-section{padding-bottom:130px}.film-cover{padding:0;margin:0 3%;width:94%;height:min(70vw,780px);max-height:80svh;border-radius:28px;overflow:hidden;position:relative;background:#eee;text-align:left;color:white}.film-cover img{width:100%;height:100%;object-fit:cover;transition:transform .8s}.film-cover:hover img{transform:scale(1.025)}.film-cover:after{content:"";position:absolute;inset:40% 0 0;background:linear-gradient(transparent,#0009)}.play-circle{position:absolute;inset:0;margin:auto;width:84px;height:84px;border-radius:50%;display:grid;place-items:center;background:#ffffffc9;backdrop-filter:blur(12px);color:#222;font-size:24px;z-index:2;padding-left:5px}.film-caption{position:absolute;left:5%;right:5%;bottom:6%;font-size:24px;z-index:2;display:flex;justify-content:space-between}.film-caption span{font-size:16px;align-self:end}dialog{padding:0;border:0;border-radius:20px;background:#000;width:min(1200px,95vw);overflow:visible}dialog::backdrop{background:#000d;backdrop-filter:blur(18px)}dialog video{width:100%;border-radius:20px;max-height:85svh}.close-dialog{position:absolute;right:12px;top:12px;width:40px;height:40px;border-radius:50%;z-index:3;background:#ffffffd9;font-size:28px}.footer{padding:60px var(--edge);background:var(--paper);display:flex;align-items:center;gap:32px;flex-wrap:wrap;font-size:14px;color:#6e6e73}.footer>div{display:flex;gap:24px;margin-left:auto}.footer small{width:100%;padding-top:25px;border-top:1px solid #d2d2d7}.footer .logo img{width:70px}@media(max-width:700px){.nav{height:58px;gap:12px}.nav nav{gap:16px;font-size:12px}.nav nav a:first-child{display:none}.logo img{width:65px}.pill.small{padding:8px 12px;font-size:12px}.hero{height:850px;max-height:calc(100svh + 120px)}.hero-copy{top:8%;}.hero h1{font-size:68px}.hero-sub{font-size:20px;margin-top:20px}.hero-art img{transform:translate(5%,22%) scale(1.35);object-fit:contain}.hero-art:after{background:linear-gradient(#f8f8f8 0%,#f8f8f8b0 32%,transparent 55%)}.hero-bottom>span{display:none}.hero-bottom{justify-content:flex-end}.hero-copy .eyebrow{font-size:15px}.manifesto{height:155vh}.manifesto-copy p{font-size:27px;margin:40px 0}.section-intro{padding:90px var(--edge) 42px}.eyebrow{font-size:16px;margin-bottom:20px}.film-cover{height:60vh;max-height:650px;margin:0 5%;width:90%;border-radius:20px}.film-cover img{object-position:40%}.film-caption{font-size:17px}.play-circle{width:64px;height:64px;font-size:20px}.film-section{padding-bottom:70px}.footer>div{margin:0}.footer p{width:100%}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}.manifesto{height:auto}.manifesto-sticky{position:relative;min-height:700px}}
.section-body{font-size:clamp(20px,1.8vw,28px);line-height:1.6;color:#6e6e73;margin-top:32px}.features{background:var(--paper);padding-bottom:110px;overflow:hidden}.gallery-tools{padding:0 var(--edge) 28px;display:flex;justify-content:space-between;color:#6e6e73;font-size:16px;align-items:center}.gallery-tools div{display:flex;gap:10px}.gallery-tools button,.book-controls button{width:44px;height:44px;border-radius:50%;background:#e7e7eb;color:#29292d;font-size:21px}.gallery-tools button:hover,.book-controls button:hover{background:#d9d9e0}.feature-track{display:flex;gap:24px;overflow:auto;padding:0 var(--edge) 40px;scroll-snap-type:x mandatory;scrollbar-width:none}.feature-track::-webkit-scrollbar{display:none}.feature-card{width:clamp(340px,34vw,510px);height:630px;flex-shrink:0;position:relative;border-radius:28px;overflow:hidden;scroll-snap-align:center;background:#ddd}.feature-card>img{width:100%;height:100%;object-fit:cover}.feature-card:nth-child(2)>img{object-position:48% 55%}.feature-card:nth-child(5)>img{object-position:64%}.feature-shade{position:absolute;inset:0;background:linear-gradient(#0008,transparent 60%,#0003)}.feature-copy{position:absolute;top:38px;left:34px;right:30px;color:white}.feature-copy>p{font-size:17px;font-weight:500;margin-bottom:20px}.feature-copy h3{font-size:clamp(30px,2.8vw,43px);letter-spacing:-.04em;line-height:1.2}.feature-plus{position:absolute;right:24px;bottom:24px;width:40px;height:40px;border-radius:50%;background:#ffffffdf;color:#333;font-size:28px}.vault{background:#202126;color:#fff}.vault-visual{position:absolute;inset:35% 0 0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:55px}.vault-visual>span{font-size:45px;letter-spacing:8px;color:#b8b8c4}.vault-visual svg{width:78px;stroke:#aaaaff;stroke-width:3;fill:none}.inline-link{display:inline-block;color:var(--accent);font-size:18px}.features>.inline-link{margin:10px var(--edge)}.future{background:#101012;color:#f5f5f7;padding-bottom:110px}.future h2 span{color:#a2a2a8}.future .section-body{color:#a2a2a8}.cinema{position:relative;margin:0 3%;border-radius:28px;overflow:hidden;aspect-ratio:16/9;background:#202023}.cinema video{width:100%;height:100%;object-fit:cover}.video-toggle{position:absolute;right:25px;top:25px;width:42px;height:42px;border-radius:50%;color:#fff;background:#0007;backdrop-filter:blur(12px)}.cinema-caption{position:absolute;bottom:0;left:0;right:0;padding:70px 5% 35px;display:flex;justify-content:space-between;align-items:end;background:linear-gradient(transparent,#0009);font-size:23px}.cinema-caption small{font-size:14px;color:#eee}.devices-section{padding-bottom:120px}.device-tabs{display:flex;justify-content:center;gap:34px;margin:10px var(--edge) 44px;overflow:auto;white-space:nowrap}.device-tabs button{padding:14px 0;border-bottom:2px solid transparent;background:none;font-size:17px;color:#86868b}.device-tabs [aria-selected=true]{border-color:#1d1d1f;color:#1d1d1f}.device-display{margin:0 3%;height:680px;border-radius:28px;overflow:hidden;position:relative;background:var(--paper)}.device-display>img{width:100%;height:100%;object-fit:cover;object-position:center}.device-display:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,transparent 25%,#0002 55%,#0009)}.device-copy{position:absolute;right:5%;top:23%;width:33%;color:white;z-index:2}.device-copy>p:first-child{font-size:16px;margin-bottom:24px}.device-copy h3{font-size:clamp(34px,4vw,60px);line-height:1.15;letter-spacing:-.035em}.device-copy>p:not(:first-child){font-size:19px;line-height:1.6;margin:26px 0;color:#f5f5f7}.device-copy a{font-size:17px;border-bottom:1px solid #fffa;padding-bottom:5px}.device-note,.theme-note{margin:25px var(--edge) 0;color:#86868b;font-size:14px;line-height:1.7}.device-display.is-desktop{background:#f0f1f5}.device-display.is-desktop>img{object-fit:contain;width:50%;padding:60px;filter:drop-shadow(0 20px 30px #0001)}.device-display.is-desktop:after{display:none}.is-desktop .device-copy{color:#1d1d1f}.is-desktop .device-copy>p:not(:first-child){color:#6e6e73}.is-desktop .device-copy a{border-color:#888}.interface-section{padding:140px var(--edge);display:grid;grid-template-columns:1.15fr 1fr;gap:8%;align-items:center;background:var(--paper)}.interface-copy h2{font-size:clamp(42px,4.4vw,72px)}.example-tabs{display:flex;gap:12px;flex-wrap:wrap;margin-top:35px}.example-tabs button{padding:11px 17px;background:#e9e9ed;border-radius:30px;color:#6e6e73;font-size:14px}.example-tabs [aria-pressed=true]{background:#1d1d1f;color:white}.app-preview{background:white;padding:30px;max-width:460px;width:100%;min-height:620px;border:1px solid #e6e6eb;border-radius:32px;box-shadow:0 30px 60px #1919390d;position:relative;margin:auto}.app-top{display:flex;align-items:center;justify-content:space-between;font-size:13px;color:#6e6e73}.app-top img{width:58px}.app-greeting{font-size:27px;font-weight:600;letter-spacing:-.03em;margin:55px 0 28px}.spoken-bubble{background:#eef2ff;border-radius:20px 20px 4px 20px;padding:20px;font-size:17px;line-height:1.7;color:#3f4255}.result-stack{display:grid;gap:10px;margin:20px 0 30px}.result-stack article{padding:13px 16px;border:1px solid #ededf2;border-radius:14px;animation:pop .4s ease-out both}.result-stack small{display:block;color:var(--accent);font-size:12px;margin-bottom:5px}.result-stack strong{font-size:16px;font-weight:500}.app-input{padding:16px;background:#f5f5f7;color:#929298;border-radius:30px;display:flex;justify-content:space-between;font-size:14px}.app-preview>small{display:block;text-align:center;margin:15px 0 0;color:#a0a0a5;font-size:12px}@keyframes pop{from{opacity:0;transform:translateY(10px) scale(.97)}to{opacity:1;transform:none}}.monthly{height:290vh;background:#ebe8e2}.monthly-sticky{height:100svh;min-height:720px;position:sticky;top:0;display:grid;grid-template-columns:.8fr 1.2fr;align-items:center;padding:80px var(--edge);gap:30px;overflow:hidden}.monthly-copy{z-index:3}.monthly-copy h2{font-size:clamp(40px,4.5vw,70px)}.book-note{font-size:13px;color:#929089;line-height:1.6;margin-top:25px}.book-controls{display:flex;align-items:center;gap:18px;margin:28px 0 14px}.book-controls button{background:#d9d6cf}.book-controls button:disabled{opacity:.35;cursor:default}.book-controls span{font-size:14px;color:#77746e}.book-hint{font-size:13px;color:#929089}.book-stage{position:relative;width:min(100%,700px);height:480px;perspective:1700px;transform:rotate(-5deg);margin:0 auto;touch-action:pan-y;filter:drop-shadow(0 35px 25px #3b301126)}.book-base{position:absolute;inset:0;display:flex;border-radius:7px;background:#c6bdb0;padding:5px;box-shadow:0 7px #d2cabb,0 10px #b8ad9a}.base-page{width:50%;background:#fcfaf4;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:25px;text-align:center}.base-page p{font-size:20px;font-weight:600}.base-page span{font-size:13px;margin-top:20px;color:#8a8070}.left-page{box-shadow:inset -15px 0 25px #6c503417}.right-page{box-shadow:inset 15px 0 25px #6c503417}.sheet{position:absolute;left:50%;top:0;width:50%;height:100%;transform-origin:left center;transform-style:preserve-3d;transition:transform 1.15s cubic-bezier(.25,.65,.15,1);}.sheet.turned{transform:rotateY(-180deg)}.paper{position:absolute;inset:0;padding:26px;background:#fffdf7;backface-visibility:hidden;overflow:hidden;box-shadow:inset 16px 0 28px #745b2912;border:1px solid #ded7c9}.paper.back{transform:rotateY(180deg);box-shadow:inset -16px 0 28px #745b2912}.cover-paper{background:#f4efe5}.edition,.page-eyebrow{font-size:12px;color:#8a8070}.cover-paper h3{font-family:Georgia,"Songti SC",serif;font-weight:500;line-height:1.3;font-size:31px;margin:28px 0 20px;letter-spacing:-.04em}.cover-paper>img{width:100%;height:220px;object-fit:cover;object-position:50% 20%}.cover-paper>small{font-size:11px;color:#9a9387;display:block;margin-top:15px}.full-page-art{position:absolute;inset:18px;width:calc(100% - 36px);height:calc(100% - 60px);object-fit:cover}.page-number{position:absolute;bottom:16px;left:24px;font-size:11px;color:#8a8070}.half-page-art{margin:20px 0;width:100%;height:170px;object-fit:cover}.paper h3{font-size:24px;font-family:Georgia,"Songti SC",serif;font-weight:500}.page-prose{margin-top:20px;font-size:14px;line-height:1.8;color:#807567}.final-page{display:flex;flex-direction:column;justify-content:center}.final-page h3{font-size:35px;line-height:1.4;margin-top:25px}.themes{padding-bottom:110px}.theme-preview{margin:0 var(--edge);position:relative;min-height:560px;border-radius:32px;background:#eef0fc;overflow:hidden;transition:background .6s}.theme-words{padding:80px 7%;position:relative;z-index:2}.theme-words>span{font-size:12px;letter-spacing:.16em;color:#8288a6}.theme-words h3{font-size:clamp(36px,4.4vw,65px);line-height:1.15;margin:30px 0;letter-spacing:-.045em}.theme-words p{color:#848598;font-size:18px}.theme-preview>img{position:absolute;right:7%;top:12%;height:68%;width:38%;object-fit:contain;transition:opacity .5s,transform .5s}.theme-preview[data-theme=simple]{background:#f5f5f7}.theme-preview[data-theme=simple]>img{opacity:0;transform:translateY(40px)}.theme-selector{position:absolute;bottom:30px;left:7%;display:flex;gap:10px;z-index:3}.theme-selector button{padding:10px 17px;border-radius:30px;background:#fff8;font-size:14px;color:#6e6e73}.theme-selector [aria-pressed=true]{background:#252630;color:white}.get-started{text-align:center;padding:150px 24px;background:var(--paper)}.get-started .pill{margin:42px 0 25px}.get-started>.inline-link{display:block;font-size:16px}.detail-dialog{background:#fff;padding:75px;width:min(820px,93vw);max-height:85vh;overflow:auto}.detail-dialog h2{font-size:48px;margin-bottom:32px}.detail-dialog>p:not(.eyebrow){font-size:20px;line-height:1.7;color:#6e6e73;margin-top:20px}.detail-dialog .close-dialog{background:#eee}.glasses-hero{height:calc(100svh - 66px);min-height:650px;position:relative;background:#1d2620;color:white;overflow:hidden}.glasses-hero>video{width:100%;height:100%;object-fit:cover}.glasses-hero:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,#0007,transparent 65%)}.glasses-title{position:absolute;left:var(--edge);bottom:12%;z-index:2}.glasses-title h1{font-size:clamp(64px,7vw,108px)}.glasses-title>p:last-child{margin-top:25px;font-size:24px;color:#ddd}.glasses-intro{text-align:center;padding:150px var(--edge)}.glasses-intro .section-body{max-width:750px;margin:35px auto 0}.glasses-grid{display:grid;grid-template-columns:1fr 1fr;gap:30px;padding:0 var(--edge) 140px}.glasses-grid article{background:var(--paper);padding:65px 45px;border-radius:28px}.glasses-grid h3{font-size:38px;line-height:1.2;letter-spacing:-.035em;margin:24px 0}.glasses-grid p{font-size:20px;line-height:1.7;color:#6e6e73}.glasses-grid .number{font-size:16px;color:var(--accent)}.compatibility-block{padding:100px var(--edge);background:#141417;color:white}.compatibility-block h2{font-size:50px}.compatibility-block p{font-size:20px;line-height:1.7;color:#aaa;max-width:800px;margin-top:30px}.download-grid-new{display:grid;grid-template-columns:repeat(2,1fr);gap:25px;padding:0 var(--edge) 100px}.download-grid-new article{padding:55px;background:var(--paper);border-radius:25px}.download-grid-new h2{font-size:38px;margin:15px 0}.download-grid-new p{font-size:18px;color:#6e6e73;line-height:1.6}.availability{display:inline-block;margin-top:30px;font-size:14px;color:#86868b;border-top:1px solid #d2d2d7;padding-top:20px}@media(max-width:1000px){.monthly-sticky{grid-template-columns:.8fr 1.2fr;padding-left:35px;padding-right:35px;gap:20px}.book-stage{height:380px}.paper{padding:18px}.cover-paper h3{font-size:25px;margin:18px 0}.cover-paper>img{height:180px}.half-page-art{height:125px}.page-prose{font-size:12px}.paper h3{font-size:21px}.feature-card{height:560px}.device-display{height:560px}}@media(max-width:700px){.features{padding-bottom:70px}.feature-card{width:82vw;height:530px;border-radius:23px}.feature-copy{left:27px;top:30px}.feature-copy h3{font-size:34px}.feature-track{gap:16px;padding-left:24px;padding-right:24px}.future{padding-bottom:65px}.cinema{margin:0;border-radius:0;aspect-ratio:4/5}.cinema video{object-position:58%}.cinema-caption{font-size:17px;gap:20px;padding-bottom:25px}.cinema-caption small{font-size:12px}.device-tabs{justify-content:flex-start;gap:24px;margin-bottom:26px}.device-tabs button{font-size:15px}.device-display{height:660px;margin:0 5%;border-radius:22px}.device-display>img{height:66%;object-position:42%}.device-display:after{background:linear-gradient(transparent 30%,#121217 70%)}.device-copy{top:auto;bottom:7%;left:8%;right:8%;width:auto}.device-copy h3{font-size:36px}.device-copy>p:first-child{margin-bottom:12px;font-size:14px}.device-copy>p:not(:first-child){font-size:16px;margin:17px 0}.device-display.is-desktop>img{width:100%;height:52%;padding:28px}.device-note{font-size:12px}.devices-section{padding-bottom:70px}.interface-section{grid-template-columns:1fr;padding:90px 24px;gap:50px}.app-preview{padding:24px;min-height:600px}.monthly{height:auto;padding:80px 0}.monthly-sticky{position:relative;height:auto;min-height:0;display:flex;flex-direction:column;padding:0 24px;overflow:visible;gap:55px}.monthly-copy{align-self:start}.monthly-copy h2{font-size:46px}.book-stage{width:100%;max-width:520px;height:330px;transform:rotate(-3deg)}.paper{padding:12px}.cover-paper h3{font-size:19px}.cover-paper>img{height:150px}.edition,.page-eyebrow{font-size:10px}.paper h3{font-size:17px}.half-page-art{height:110px;margin:15px 0}.page-prose{font-size:11px;margin-top:12px}.page-number{font-size:9px;left:13px}.book-hint{font-size:0}.book-hint:after{content:'左右滑动，翻阅书页';font-size:13px}.themes{padding-bottom:70px}.theme-preview{margin:0 24px;min-height:650px}.theme-words{padding:45px 28px}.theme-words h3{font-size:39px}.theme-preview>img{width:75%;height:42%;top:auto;bottom:75px;right:10%}.theme-words p{font-size:16px}.theme-selector{left:28px;bottom:25px}.get-started{padding:95px 24px}.get-started h2{font-size:43px}.detail-dialog{padding:55px 28px}.detail-dialog h2{font-size:35px}.detail-dialog>p:not(.eyebrow){font-size:18px}.glasses-hero{min-height:730px}.glasses-hero>video{object-position:42%}.glasses-title{bottom:10%}.glasses-title h1{font-size:60px}.glasses-title>p:last-child{font-size:20px}.glasses-intro{padding:95px 24px}.glasses-grid{grid-template-columns:1fr;padding:0 24px 80px}.glasses-grid article{padding:40px 28px}.glasses-grid h3{font-size:32px}.compatibility-block{padding:75px 24px}.compatibility-block h2{font-size:40px}.download-grid-new{grid-template-columns:1fr;padding:0 24px 75px}.download-grid-new article{padding:38px 28px}}

/* The frosted second screen physically slides over the pinned hero. */
.opening-sequence{position:relative}
.opening-sequence>.hero{position:sticky;top:66px;height:calc(100svh - 66px);min-height:0;max-height:none;z-index:0}
.opening-sequence .manifesto{position:relative;z-index:2;height:190svh}
.opening-sequence .manifesto-sticky{top:66px;height:calc(100svh - 66px);overflow:hidden;border-top:1px solid #ffffffb3;box-shadow:0 -18px 65px #29252b0b}
.opening-sequence .frost{opacity:1;background:rgba(248,248,250,.64);-webkit-backdrop-filter:blur(28px) saturate(1.15);backdrop-filter:blur(28px) saturate(1.15)}
.opening-sequence .manifesto-copy{position:relative}
@media(max-width:700px){.opening-sequence>.hero{top:58px;height:calc(100svh - 58px)}.opening-sequence .manifesto-sticky{top:58px;height:calc(100svh - 58px)}.opening-sequence .manifesto{height:160svh}.opening-sequence .manifesto-copy p{font-size:25px;margin:32px 0}}
@media(prefers-reduced-motion:reduce){.opening-sequence>.hero{position:relative;top:0}.opening-sequence .manifesto{height:auto}.opening-sequence .manifesto-sticky{position:relative;top:0;height:auto;min-height:650px}.opening-sequence .frost{background:#f5f5f7}}

/* Keep both faces in the same 3D sheet; the moving sheet stays above the stack. */
.book-stage{filter:none}.book-base{box-shadow:0 7px #d2cabb,0 10px #b8ad9a,0 35px 35px #3b301126}
.sheet{-webkit-transform-style:preserve-3d;transform-style:preserve-3d}.paper{-webkit-backface-visibility:hidden;backface-visibility:hidden;transform:rotateY(0deg) translateZ(.1px)}.paper.back{transform:rotateY(180deg) translateZ(.1px)}

/* One scroll position controls all sheets; CSS transitions must not queue. */
.book-stage .sheet{transition:none!important;will-change:transform}