:root{
  --bg:#0f1e18;--bg-2:#132720;--surface:#182f26;--line:#2a4337;--line-soft:#21382e;
  --ink:#f1eee2;--dim:#b3bfb0;--faint:#7f907f;--amber:#e7b46a;--amber-ink:#2b1d0c;
  --serif:"New York",ui-serif,Georgia,"Songti TC","Noto Serif TC","Noto Serif CJK TC",serif;
  --sans:-apple-system,BlinkMacSystemFont,"SF Pro Text","PingFang TC","Hiragino Sans","Microsoft JhengHei",system-ui,sans-serif;
  color-scheme:dark;
}
:lang(zh-Hans){--serif:"New York",ui-serif,Georgia,"Songti SC","Noto Serif SC","Noto Serif CJK SC",serif;--sans:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",system-ui,sans-serif}
:lang(ja){--serif:"New York",ui-serif,Georgia,"Hiragino Mincho ProN","Yu Mincho","Noto Serif JP",serif;--sans:-apple-system,BlinkMacSystemFont,"Hiragino Sans","Yu Gothic",system-ui,sans-serif}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:20px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.75 var(--sans);overflow-x:hidden}
body::before{content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:radial-gradient(1100px 620px at 78% -8%,#2d4b3a 0%,transparent 62%),radial-gradient(800px 520px at 8% 30%,#1b3428 0%,transparent 70%),var(--bg)}
h1,h2,h3,p,figure,dl,dd,ul{margin:0}
ul{padding:0;list-style:none}
a{color:inherit;text-underline-offset:.28em}
img{max-width:100%}
button{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--amber);outline-offset:4px;border-radius:6px}
.wrap{width:min(1240px,calc(100% - 32px));margin-inline:auto}
.skip{position:absolute;left:16px;top:-60px;background:var(--ink);color:var(--bg);padding:8px 14px;border-radius:8px;z-index:9}
.skip:focus{top:12px}
.eyebrow{font-size:13px;letter-spacing:.14em;text-transform:uppercase;color:var(--amber);margin-bottom:18px}
:lang(zh-Hant) .eyebrow,:lang(zh-Hans) .eyebrow,:lang(ja) .eyebrow{letter-spacing:.2em}

/* header */
.top{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:84px}
.brand{display:inline-flex;align-items:center;gap:11px;text-decoration:none;font:500 21px/1 var(--serif);letter-spacing:-.01em;white-space:nowrap}
.brand img{border-radius:9px;box-shadow:0 0 0 1px #ffffff1a}
.top-nav{display:flex;align-items:center;gap:26px;font-size:14px}
.top-nav>a{text-decoration:none;color:var(--dim)}
.top-nav>a.nav-duo{color:var(--amber)}
.top-nav>a:hover{color:var(--ink)}
.top-nav .nav-cta{color:var(--bg);background:var(--ink);padding:9px 18px;border-radius:99px;font-weight:600}
.top-nav .nav-cta:hover{background:var(--amber);color:var(--amber-ink)}
.langmenu{position:relative}
.langmenu summary{list-style:none;cursor:pointer;color:var(--dim);display:flex;align-items:center;gap:6px}
.langmenu summary::-webkit-details-marker{display:none}
.langmenu summary svg{flex:none;opacity:.85}
.langmenu summary:hover{color:var(--ink)}
.lang-list{position:absolute;right:0;top:calc(100% + 10px);display:grid;gap:2px;min-width:150px;padding:8px;background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:0 18px 40px #00000059;z-index:5}
.lang-list a{padding:8px 12px;border-radius:9px;text-decoration:none;color:var(--dim)}
.lang-list a:hover,.lang-list a[aria-current]{background:#ffffff0f;color:var(--ink)}

/* hero */
.hero{padding-top:48px}
.pill{display:inline-flex;align-items:center;gap:9px;margin-bottom:28px;padding:7px 14px;border-radius:99px;border:1px solid #e7b46a59;background:#e7b46a14;color:var(--amber);font-size:14px;line-height:1.4;text-decoration:none;transition:background .18s}
.pill:hover{background:#e7b46a2b}
.pill svg{flex:none}
.hero-copy{text-align:center;max-width:820px;margin:0 auto}
.hero h1{font:400 clamp(42px,6.2vw,84px)/1.12 var(--serif);letter-spacing:-.035em;text-wrap:balance}
.heading-line{display:block;text-wrap:balance}
.heading-line+br{display:none}
:lang(ja) .heading-line{line-break:strict}
:lang(zh-Hant) .hero h1,:lang(zh-Hans) .hero h1,:lang(ja) .hero h1{letter-spacing:.01em;line-height:1.22}
.lead{margin:26px auto 0;max-width:620px;font-size:17px;color:var(--dim);text-wrap:pretty}
.actions{display:flex;flex-wrap:wrap;justify-content:center;align-items:center;gap:14px 26px;margin-top:34px}
.button{display:inline-flex;align-items:center;gap:12px;background:var(--amber);color:var(--amber-ink);font-weight:600;text-decoration:none;padding:15px 26px;border-radius:99px;box-shadow:0 10px 30px #e7b46a29;transition:transform .18s,background .18s}
.button:hover{background:#f1c682;transform:translateY(-2px)}
.listen{display:inline-flex;align-items:center;gap:10px;background:none;border:0;padding:10px 4px;cursor:pointer;color:var(--ink);font-size:15px}
.listen:hover #sound-label{text-decoration:underline;text-underline-offset:5px}
.wave{display:inline-flex;align-items:center;gap:3px;height:20px}
.wave i{width:3px;height:8px;border-radius:2px;background:var(--amber);transition:height .3s}
.wave i:nth-child(2){height:16px}.wave i:nth-child(3){height:12px}.wave i:nth-child(4){height:6px}
.listen[aria-pressed=true] .wave i{animation:wave 1.1s ease-in-out infinite}
.listen[aria-pressed=true] .wave i:nth-child(2){animation-delay:-.3s}.listen[aria-pressed=true] .wave i:nth-child(3){animation-delay:-.6s}.listen[aria-pressed=true] .wave i:nth-child(4){animation-delay:-.15s}
@keyframes wave{50%{height:20px}}
.fine{margin-top:18px;font-size:13px;color:var(--faint)}
#notice{display:block;font-size:14px;color:var(--amber);min-height:1px}
.window{position:relative;margin:56px auto 0;border-radius:28px;overflow:hidden;box-shadow:0 0 0 1px #ffffff14,0 40px 90px -20px #000000b3,0 0 120px -30px #e7b46a40}
.window img{display:block;width:100%;height:auto}
.facts{display:grid;grid-template-columns:repeat(5,1fr);margin-top:44px;border-top:1px solid var(--line)}
.facts div{padding:24px 24px 0 0}
.facts div+div{padding-left:24px;border-left:1px solid var(--line-soft)}
.facts dt{font:500 19px/1.3 var(--serif);margin-bottom:8px}
.facts dd{font-size:14px;color:var(--dim);line-height:1.65}

/* section heads */
.section-head{max-width:640px;margin-bottom:56px}
.section-head h2,.collection h2,.closing h2{font:400 clamp(26px,4vw,54px)/1.2 var(--serif);letter-spacing:-.02em;text-wrap:balance}
:lang(en) #faq-title{font-size:clamp(24px,4vw,54px)}
:lang(zh-Hant) h2,:lang(zh-Hans) h2,:lang(ja) h2{letter-spacing:.01em}
.section-head>p:not(.eyebrow){margin-top:18px;color:var(--dim);font-size:16px}

/* modes */
.modes{padding-top:150px}
.mode{display:grid;grid-template-columns:1fr minmax(220px,290px);align-items:center;gap:clamp(32px,8vw,120px);padding:56px 0;border-top:1px solid var(--line-soft)}
.mode:nth-of-type(even){grid-template-columns:minmax(220px,290px) 1fr}
.mode:nth-of-type(even) .mode-copy{order:2}
.mode-copy{max-width:520px}
.tag{display:inline-flex;align-items:center;gap:9px;font-size:14px;color:var(--dim);margin-bottom:18px}
.tag span{width:7px;height:7px;border-radius:50%;background:var(--amber);box-shadow:0 0 12px var(--amber)}
.mode h3{font:400 clamp(26px,2.8vw,38px)/1.3 var(--serif);letter-spacing:-.01em}
.mode-copy>p{margin-top:16px;color:var(--dim)}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:24px}
.chips li{font-size:13px;padding:6px 14px;border-radius:99px;border:1px solid var(--line);color:var(--ink);background:#ffffff08}
.phone{justify-self:center;width:100%;max-width:290px}
.phone img{display:block;width:100%;height:auto}

/* iPhone Duo */
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
.duo{padding-top:150px}
.fold{display:grid;grid-template-columns:minmax(0,.82fr) minmax(0,1.18fr);gap:clamp(28px,5vw,80px);align-items:center}
.fold .section-head{margin-bottom:34px}
.fold-track.pin .fold{position:sticky}
.more{display:inline-flex;align-items:center;gap:8px;margin-top:22px;color:var(--amber);text-decoration:none;font-size:15px}
.more:hover{text-decoration:underline;text-underline-offset:5px}
.more svg{transition:transform .18s}
.more:hover svg{transform:translateX(3px)}
.poses{display:grid;gap:4px;margin:0;padding:0;border:0;min-width:0}
.pose{position:relative;display:block;padding:13px 18px;border-radius:16px;border:1px solid transparent;cursor:pointer;color:var(--dim);font-size:14px;line-height:1.6;transition:background .25s,border-color .25s}
.pose input{position:absolute;opacity:0;pointer-events:none}
.pose strong{display:block;font:500 19px/1.35 var(--serif);color:var(--ink);transition:color .25s}
.pose:hover{background:#ffffff08}
.pose:has(:checked){background:#ffffff0d;border-color:var(--line)}
.pose:has(:checked) strong{color:var(--amber)}
.pose:has(:focus-visible){outline:2px solid var(--amber);outline-offset:2px}
.fold-stage{position:relative;aspect-ratio:1/.8;border-radius:32px;border:1px solid var(--line-soft);background:radial-gradient(58% 52% at 50% 46%,#e7b46a24,transparent 72%),linear-gradient(160deg,#1b3329,#11231b)}
.shot{position:absolute;inset:0;margin:auto;height:auto;opacity:0;transition:opacity .6s ease}
.shot-closed{width:43.5%}
.shot-book{width:76%}
.shot-laptop{width:75%}
.shot-open{width:86%}
.fold:has([value=closed]:checked) .shot-closed,.fold:has([value=book]:checked) .shot-book,.fold:has([value=laptop]:checked) .shot-laptop,.fold:has([value=open]:checked) .shot-open{opacity:1}

/* iPhone Duo page */
.crumbs{display:flex;justify-content:center;gap:10px;margin-bottom:26px;font-size:13px;color:var(--faint)}
.crumbs a{color:var(--dim);text-decoration:none}
.crumbs a:hover{color:var(--ink)}
.crumbs [aria-current]{color:var(--amber)}
.duo-page .hero h1{font-size:clamp(28px,4.6vw,62px)}
:lang(ja) .duo-page .hero-copy{max-width:1040px}
.duo-page .fold{margin-top:72px}
.keep{padding-top:150px}
.facts.four{grid-template-columns:repeat(4,1fr);margin-top:0}

/* collection */
.collection{display:grid;grid-template-columns:1fr minmax(240px,340px);align-items:center;gap:clamp(32px,8vw,120px);margin-top:110px;padding:72px clamp(24px,6vw,80px);border-radius:32px;background:linear-gradient(140deg,#1b3329,#11231b);border:1px solid var(--line-soft)}
.collection-copy>p:not(.eyebrow){margin-top:18px;color:var(--dim);max-width:520px}
.points{margin-top:28px;display:grid;gap:14px}
.points li{position:relative;padding-left:28px;color:var(--ink)}
.points li::before{content:"";position:absolute;left:0;top:.62em;width:14px;height:1.5px;background:var(--amber)}

/* faq */
.faq{padding-top:150px}
.faq .section-head{margin-bottom:28px}
.faq-list{border-top:1px solid var(--line)}
.faq details{border-bottom:1px solid var(--line)}
.faq summary{list-style:none;cursor:pointer;display:flex;justify-content:space-between;align-items:center;gap:24px;padding:24px 0}
.faq summary::-webkit-details-marker{display:none}
.faq summary h3{font:400 clamp(18px,1.8vw,22px)/1.45 var(--serif)}
.faq summary::after{content:"";flex:none;width:12px;height:12px;border-right:1.5px solid var(--dim);border-bottom:1.5px solid var(--dim);transform:rotate(45deg) translate(-3px,-3px);transition:transform .2s}
.faq details[open] summary::after{transform:rotate(-135deg)}
.faq details p{padding:0 48px 28px 0;color:var(--dim);max-width:820px}

/* closing */
.closing{text-align:center;padding:150px 0 130px}
.closing img{border-radius:16px;margin-bottom:28px;box-shadow:0 0 0 1px #ffffff1a,0 20px 50px #00000080}
.closing p{color:var(--dim);margin:20px auto 34px;max-width:520px}
.closing small{display:block;margin-top:16px;color:var(--faint);font-size:13px}

/* footer */
.foot{border-top:1px solid var(--line-soft);padding:44px 0 56px;font-size:14px;color:var(--dim)}
.foot-inner{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:28px;align-items:start}
.foot .brand{color:var(--ink);font-size:19px}
.foot p{margin-top:12px}
.foot nav{display:flex;flex-wrap:wrap;gap:10px 22px}
.foot nav a{text-decoration:none}
.foot nav a:hover,.foot nav a[aria-current]{color:var(--ink)}
.credit{margin-top:32px;font-size:12px;color:var(--faint)}

/* language suggestion */
.lang-hint{position:fixed;left:16px;right:16px;bottom:20px;margin-inline:auto;width:fit-content;z-index:20;display:flex;align-items:center;gap:14px;max-width:calc(100% - 32px);padding:10px 10px 10px 18px;border-radius:99px;background:#f1eee2;color:#13241c;font-size:14px;box-shadow:0 18px 40px #00000066}
.lang-hint a{font-weight:600;background:#13241c;color:#f1eee2;padding:7px 14px;border-radius:99px;text-decoration:none;white-space:nowrap}
.lang-hint button{border:0;background:none;cursor:pointer;font-size:18px;line-height:1;padding:4px 8px;color:#13241c}

@media (max-width:900px){
  .facts{grid-template-columns:1fr 1fr}
  .facts div:nth-child(odd){padding-left:0;border-left:0}
  .facts div:last-child{grid-column:1/-1}
  .facts.four div:last-child{grid-column:auto}
  .fold{grid-template-columns:1fr}
  .poses{grid-template-columns:1fr 1fr}
  .mode,.mode:nth-of-type(even),.collection{grid-template-columns:1fr;gap:40px}
  .mode:nth-of-type(even) .mode-copy{order:0}
  .phone{max-width:250px}
  .foot-inner{grid-template-columns:1fr}
}
@media (max-width:640px){
  .hide-sm{display:none}
  .top{min-height:68px}
  .top-nav{gap:14px}
  .top-nav .nav-cta{padding:8px 14px;font-size:13px}
  .langmenu summary span{display:none}
  .langmenu summary svg{width:19px;height:19px}
  .brand{font-size:18px}
  .brand img{width:30px;height:30px}
  .hero{padding-top:28px}
  .hero h1{font-size:clamp(28px,10vw,42px)}
  .lead{font-size:16px}
  .window{margin-top:40px;border-radius:18px}
  .facts{grid-template-columns:1fr;margin-top:32px}
  .facts div,.facts div+div{padding:18px 0;border-left:0;border-bottom:1px solid var(--line-soft)}
  .modes,.faq,.duo,.keep{padding-top:100px}
  .duo-page .fold{margin-top:48px}
  .fold-stage{border-radius:22px}
  .pose{padding:11px 13px;font-size:13px}
  .pose strong{font-size:17px}
  .section-head{margin-bottom:32px}
  .mode{padding:44px 0}
  .collection{margin-top:72px;padding:44px 22px;border-radius:24px}
  .faq details p{padding-right:0}
  .closing{padding:100px 0 90px}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.button,.wave i,.shot{transition:none}.listen[aria-pressed=true] .wave i{animation:none}}