/* ========================================================================
   sotoby · 新途标 — Apple-style minimalist, white, highly animated
   Self-contained: no external fonts / libraries / CDNs (China-friendly)
   ===================================================================== */

:root{
  --bg:#ffffff;
  --bg-soft:#fbfbfd;
  --bg-soft-2:#f5f5f7;
  --ink:#1d1d1f;
  --ink-soft:#6e6e73;
  --ink-faint:#86868b;
  --line:rgba(0,0,0,.08);
  --blue:#0071e3;
  --blue-d:#0058b9;
  --blue-l:#2997ff;
  --cyan:#26d3ff;
  --navy:#04204e;
  --grad:linear-gradient(120deg,#0a84ff 0%,#28c8ff 55%,#5ad1ff 100%);
  --grad-deep:linear-gradient(135deg,#04204e 0%,#0a5bd6 60%,#26d3ff 100%);
  --shadow-s:0 2px 10px rgba(0,0,0,.05);
  --shadow-m:0 18px 50px rgba(8,40,100,.12);
  --shadow-l:0 40px 90px rgba(8,40,100,.18);
  --r:22px;
  --nav-h:62px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --ease-out:cubic-bezier(.16,1,.3,1);
  --font:-apple-system,BlinkMacSystemFont,"SF Pro Display","Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font);
  color:var(--ink);
  background:var(--bg);
  line-height:1.5;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
:lang(zh) .intro-title,:lang(zh) .section-title,:lang(zh) .contact-title{letter-spacing:.01em}

/* ---------- shared wrap ---------- */
.wrap{width:min(1120px,92vw);margin:0 auto}

/* ====================================================================
   NAV
   ================================================================= */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  height:var(--nav-h);
  background:rgba(255,255,255,.72);
  backdrop-filter:saturate(180%) blur(20px);
  -webkit-backdrop-filter:saturate(180%) blur(20px);
  border-bottom:1px solid transparent;
  transition:border-color .4s,background .4s;
}
.nav.scrolled{border-color:var(--line)}
.nav-inner{
  width:min(1120px,92vw);margin:0 auto;height:100%;
  display:flex;align-items:center;gap:18px;
}
.nav-logo{display:flex;align-items:center;gap:11px;height:100%}
.nav-logo img{height:42px;width:auto}
.nav-zh{
  /* 圆润光滑字体优先，逐级回退到依然漂亮的平滑字体 */
  font-family:"Yuanti SC","YuanTi SC","STYuanti","华文圆体","Hiragino Maru Gothic ProN","Hiragino Maru Gothic Pro","YouYuan","幼圆","PingFang SC","Microsoft YaHei","微软雅黑",system-ui,sans-serif;
  font-size:23px;font-weight:600;letter-spacing:.1em;line-height:1;
  color:var(--navy);
  padding-left:12px;border-left:1px solid var(--line);
  white-space:nowrap;
}
@media(max-width:480px){
  .nav-zh{font-size:19px;padding-left:9px;letter-spacing:.06em}
  .nav-logo img{height:36px}
}
.nav-links{margin-left:auto;display:flex;gap:30px}
.nav-links a{
  font-size:14px;color:var(--ink-soft);font-weight:450;
  position:relative;transition:color .25s;
}
.nav-links a:hover{color:var(--ink)}
.nav-links a::after{
  content:"";position:absolute;left:0;right:0;bottom:-6px;height:2px;
  background:var(--grad);transform:scaleX(0);transform-origin:left;
  transition:transform .3s var(--ease);border-radius:2px;
}
.nav-links a:hover::after{transform:scaleX(1)}
.lang-toggle{
  margin-left:6px;border:1px solid var(--line);background:rgba(255,255,255,.6);
  border-radius:100px;padding:7px 13px;font-family:var(--font);
  font-size:13px;font-weight:600;color:var(--ink-soft);cursor:pointer;
  display:flex;align-items:center;gap:3px;transition:.25s;
}
.lang-toggle:hover{border-color:var(--blue);color:var(--blue)}
.lang-toggle .lang-sep{opacity:.35;font-weight:400}
html[lang="en"] .lang-toggle .lang-en{color:var(--blue)}
html[lang="zh"] .lang-toggle .lang-zh{color:var(--blue)}

@media(max-width:720px){
  .nav-links{display:none}
}

/* ====================================================================
   HERO SLIDESHOW
   ================================================================= */
.show{
  position:relative;
  height:100svh;min-height:560px;
  overflow:hidden;
  background:var(--bg);
}
/* aurora background blobs */
.show-aurora,.contact-aurora{position:absolute;inset:0;overflow:hidden;pointer-events:none;z-index:0}
.blob{
  position:absolute;border-radius:50%;filter:blur(70px);opacity:.5;
  will-change:transform;
}
.show-aurora .b1{width:46vw;height:46vw;left:-8vw;top:-6vw;background:radial-gradient(circle,#a8e0ff,transparent 70%);animation:float1 18s var(--ease) infinite}
.show-aurora .b2{width:40vw;height:40vw;right:-6vw;top:8vw;background:radial-gradient(circle,#bfe9ff,transparent 70%);animation:float2 22s var(--ease) infinite}
.show-aurora .b3{width:38vw;height:38vw;left:24vw;bottom:-14vw;background:radial-gradient(circle,#d4ccff,transparent 70%);animation:float3 26s var(--ease) infinite;opacity:.4}
@keyframes float1{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(8vw,5vw) scale(1.12)}}
@keyframes float2{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(-7vw,6vw) scale(1.08)}}
@keyframes float3{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(5vw,-6vw) scale(1.15)}}

.show-progress{position:absolute;top:0;left:0;right:0;height:3px;z-index:6;background:rgba(0,0,0,.05)}
.show-progress span{display:block;height:100%;width:0;background:var(--grad);transition:width .15s linear}

.show-track{position:relative;z-index:2;display:flex;height:100%;width:100%;
  transition:transform .7s var(--ease-out);will-change:transform}
.slide{
  position:relative;flex:0 0 100%;width:100%;height:100%;
  display:flex;align-items:center;justify-content:center;
  padding:calc(var(--nav-h) + 22px) 6vw 64px;
}
.slide-c{width:min(1080px,100%);margin:0 auto}

/* ---- intro slide ---- */
.intro-c{text-align:center;display:flex;flex-direction:column;align-items:center}
.eyebrow{
  font-size:clamp(13px,1.6vw,16px);font-weight:600;letter-spacing:.18em;
  text-transform:uppercase;color:var(--blue);margin-bottom:22px;
}
.intro-title{
  font-size:clamp(44px,8.4vw,108px);line-height:1.04;font-weight:700;
  letter-spacing:-.03em;margin-bottom:26px;overflow-wrap:break-word;
  background:linear-gradient(120deg,#04204e 10%,#0a5bd6 50%,#26d3ff 92%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
  background-size:200% auto;animation:shimmer 7s linear infinite;
}
@keyframes shimmer{to{background-position:200% center}}
.intro-sub{
  font-size:clamp(17px,2.3vw,23px);color:var(--ink-soft);font-weight:400;
  max-width:720px;margin:0 auto 38px;line-height:1.5;
}
.intro-cta{display:flex;gap:14px;flex-wrap:wrap;justify-content:center}

.scroll-hint{
  position:absolute;bottom:26px;left:0;right:0;text-align:center;
  font-size:12.5px;color:var(--ink-faint);letter-spacing:.08em;
  display:flex;flex-direction:column;align-items:center;gap:9px;
}
.scroll-dot{width:22px;height:36px;border:1.5px solid var(--ink-faint);border-radius:14px;position:relative}
.scroll-dot::after{content:"";position:absolute;top:7px;left:50%;width:3px;height:7px;border-radius:3px;background:var(--ink-faint);transform:translateX(-50%);animation:scrolly 1.8s var(--ease) infinite}
@keyframes scrolly{0%{opacity:0;transform:translate(-50%,0)}40%{opacity:1}100%{opacity:0;transform:translate(-50%,12px)}}

/* ---- product slide (full-bleed image fills the frame) ---- */
.slide-prod{padding:0;background:linear-gradient(155deg,var(--g1),var(--g2))}
.slide-bg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;z-index:0}
.slide-prod.is-active .slide-bg{animation:bgZoom 10s ease-out both}
@keyframes bgZoom{from{transform:scale(1.09)}to{transform:scale(1)}}
.slide-scrim{position:absolute;inset:0;z-index:1;
  background:
    linear-gradient(180deg,rgba(6,14,30,.28) 0%,rgba(6,14,30,0) 22%,rgba(6,14,30,.08) 48%,rgba(6,14,30,.80) 100%),
    linear-gradient(90deg,rgba(6,14,30,.58) 0%,rgba(6,14,30,.14) 44%,rgba(6,14,30,0) 72%);
}
.slide-overlay{position:relative;z-index:2;width:100%;height:100%;display:flex;align-items:flex-end;
  padding:calc(var(--nav-h) + 30px) 7vw clamp(60px,12vh,120px)}
.overlay-inner{max-width:660px;color:#fff}
.prod-index{font-size:13px;font-weight:600;letter-spacing:.16em;color:#a9e2ff;text-transform:uppercase;margin-bottom:14px}
.prod-name{font-size:clamp(13px,1.5vw,15px);font-weight:600;letter-spacing:.05em;color:rgba(255,255,255,.86);margin-bottom:12px}
.prod-big{
  font-size:clamp(36px,6vw,78px);line-height:1.03;font-weight:700;
  letter-spacing:-.025em;margin-bottom:18px;color:#fff;text-shadow:0 2px 34px rgba(0,0,0,.36);
}
.prod-big em{font-style:normal;color:#5fe0ff;-webkit-text-fill-color:#5fe0ff}
.prod-small{font-size:clamp(15px,2vw,20px);color:rgba(255,255,255,.93);line-height:1.5;margin-bottom:24px;max-width:36ch;text-shadow:0 1px 18px rgba(0,0,0,.32)}
.prod-chips{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:26px}
.chip{font-size:12.5px;font-weight:500;color:#fff;background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.32);padding:6px 14px;border-radius:100px;backdrop-filter:blur(6px)}
.prod-more{display:inline-flex;align-items:center;gap:6px;font-size:15px;font-weight:600;color:#fff;cursor:pointer}
.prod-more.is-soon{color:rgba(255,255,255,.78);cursor:default}
.prod-more svg{width:16px;height:16px}

/* slide content reveal */
.slide .reveal,.slide-prod .overlay-inner>*{opacity:0;transform:translateY(26px)}
.slide.is-active .reveal,.slide-prod.is-active .overlay-inner>*{animation:slideRise .9s var(--ease-out) forwards}
.slide-prod.is-active .overlay-inner>*:nth-child(1){animation-delay:.10s}
.slide-prod.is-active .overlay-inner>*:nth-child(2){animation-delay:.17s}
.slide-prod.is-active .overlay-inner>*:nth-child(3){animation-delay:.24s}
.slide-prod.is-active .overlay-inner>*:nth-child(4){animation-delay:.31s}
.slide-prod.is-active .overlay-inner>*:nth-child(5){animation-delay:.38s}
.slide-prod.is-active .overlay-inner>*:nth-child(6){animation-delay:.45s}
.slide-intro.is-active .reveal:nth-child(1){animation-delay:.05s}
.slide-intro.is-active .reveal:nth-child(2){animation-delay:.14s}
.slide-intro.is-active .reveal:nth-child(3){animation-delay:.24s}
.slide-intro.is-active .reveal:nth-child(4){animation-delay:.34s}
@keyframes slideRise{to{opacity:1;transform:none}}

/* arrows */
.show-arrow{
  position:absolute;top:50%;transform:translateY(-50%);z-index:7;
  width:46px;height:46px;border-radius:50%;border:1px solid var(--line);
  background:rgba(255,255,255,.7);backdrop-filter:blur(10px);
  display:flex;align-items:center;justify-content:center;cursor:pointer;
  color:var(--ink);transition:.25s;box-shadow:var(--shadow-s);
}
.show-arrow:hover{background:#fff;color:var(--blue);transform:translateY(-50%) scale(1.08)}
.show-arrow svg{width:22px;height:22px}
.show-arrow.prev{left:24px}
.show-arrow.next{right:24px}

/* bottom control bar: pause button + dots (subtle pill, legible on white & photos) */
.show-controls{
  position:absolute;bottom:22px;left:50%;transform:translateX(-50%);z-index:7;
  display:flex;align-items:center;gap:11px;
  padding:7px 14px;border-radius:100px;
  background:rgba(18,22,34,.32);border:1px solid rgba(255,255,255,.16);
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
}
.show-pause{
  width:22px;height:22px;padding:0;border:none;background:transparent;cursor:pointer;
  display:flex;align-items:center;justify-content:center;color:#fff;transition:transform .2s,opacity .2s;
}
.show-pause:hover{transform:scale(1.12);opacity:.85}
.show-pause svg{width:15px;height:15px;fill:currentColor}
.show-pause .ic-play{display:none}
.show-pause.is-paused .ic-pause{display:none}
.show-pause.is-paused .ic-play{display:block}
.show-divider{width:1px;height:14px;background:rgba(255,255,255,.26)}
.show-dots{display:flex;gap:8px;align-items:center}
.dot{width:7px;height:7px;border-radius:50%;background:rgba(255,255,255,.45);border:none;cursor:pointer;padding:0;transition:.3s}
.dot:hover{background:rgba(255,255,255,.7)}
.dot.active{width:22px;border-radius:4px;background:#fff}

@media(max-width:860px){
  .slide-overlay{padding:calc(var(--nav-h) + 24px) 6vw clamp(46px,10vh,90px)}
  .prod-chips{gap:7px}
  .show-arrow{width:38px;height:38px}
  .show-arrow svg{width:18px;height:18px}
  .show-arrow.prev{left:8px}
  .show-arrow.next{right:8px}
  .scroll-hint{display:none}
  .intro-sub{font-size:16.5px}
}

/* ====================================================================
   GENERIC SECTIONS
   ================================================================= */
.section{padding:clamp(80px,13vh,150px) 0;position:relative}
.section.what{background:var(--bg-soft)}
.section.who{background:var(--bg)}
.section.products{background:var(--bg-soft)}
.section.approach{background:var(--bg)}

.kicker{font-size:14px;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:var(--blue);margin-bottom:16px}
.section-title{font-size:clamp(30px,5vw,56px);line-height:1.07;font-weight:700;letter-spacing:-.025em;max-width:16ch;margin-bottom:18px}
.section-lead{font-size:clamp(16px,2vw,20px);color:var(--ink-soft);max-width:54ch;line-height:1.5;margin-bottom:54px}

/* ---- capability grid ---- */
.cap-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.cap{
  background:#fff;border:1px solid var(--line);border-radius:var(--r);
  padding:34px 30px;transition:transform .45s var(--ease-out),box-shadow .45s;
}
.cap:hover{transform:translateY(-7px);box-shadow:var(--shadow-m)}
.cap-ic{
  width:54px;height:54px;border-radius:15px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,#eaf4ff,#e6f9ff);margin-bottom:20px;
}
.cap-ic svg{width:28px;height:28px;stroke:var(--blue);fill:none;stroke-width:1.7}
.cap h3{font-size:20px;font-weight:600;letter-spacing:-.01em;margin-bottom:9px}
.cap p{font-size:15px;color:var(--ink-soft);line-height:1.55}

@media(max-width:860px){.cap-grid{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.cap-grid{grid-template-columns:1fr}}

/* ---- who grid ---- */
.who-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}
.who-card{
  position:relative;border-radius:28px;padding:46px 42px;overflow:hidden;
  background:linear-gradient(150deg,#0a5bd6,#26d3ff);color:#fff;
  box-shadow:var(--shadow-m);min-height:280px;
  display:flex;flex-direction:column;justify-content:flex-end;
}
.who-card-alt{background:linear-gradient(150deg,#04204e,#0a5bd6)}
.who-card::before{content:"";position:absolute;width:240px;height:240px;border-radius:50%;
  background:rgba(255,255,255,.14);top:-90px;right:-70px;filter:blur(8px)}
.who-tag{font-size:13px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;opacity:.85;margin-bottom:14px;position:relative}
.who-card h3{font-size:clamp(24px,3.4vw,34px);font-weight:700;letter-spacing:-.02em;line-height:1.1;margin-bottom:12px;position:relative}
.who-card p{font-size:16.5px;line-height:1.55;opacity:.92;position:relative}
@media(max-width:760px){.who-grid{grid-template-columns:1fr}.who-card{min-height:220px;padding:38px 32px}}

/* ---- products grid ---- */
.prod-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.pcard{
  background:#fff;border:1px solid var(--line);border-radius:24px;overflow:hidden;
  transition:transform .5s var(--ease-out),box-shadow .5s;cursor:pointer;
  display:flex;flex-direction:column;
}
.pcard:hover{transform:translateY(-8px);box-shadow:var(--shadow-m)}
.pcard-top{position:relative;aspect-ratio:16/10;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(155deg,var(--g1),var(--g2));color:#fff;overflow:hidden}
.pcard-top .pimg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.pcard-top .pimg.hide{display:none}
.pcard-ic{width:60px;height:60px;display:flex;align-items:center;justify-content:center;
  background:rgba(255,255,255,.2);border:1px solid rgba(255,255,255,.35);border-radius:18px}
.pcard-ic svg{width:32px;height:32px;stroke:#fff;fill:none;stroke-width:1.7}
.pcard:hover .pcard-top{}
.pcard:hover .pimg,.pcard:hover .pcard-ic{transform:scale(1.05)}
.pcard-ic,.pimg{transition:transform .6s var(--ease-out)}
.pcard-body{padding:22px 22px 24px}
.pcard-body h3{font-size:18.5px;font-weight:650;letter-spacing:-.01em;margin-bottom:6px}
.pcard-body .pcat{font-size:12px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--blue);margin-bottom:10px;display:block}
.pcard-body p{font-size:14.5px;color:var(--ink-soft);line-height:1.5}
@media(max-width:860px){.prod-grid{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.prod-grid{grid-template-columns:1fr}}

/* ---- approach ---- */
.appr-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.appr{padding:6px 4px}
.appr-no{font-size:clamp(40px,5vw,58px);font-weight:700;letter-spacing:-.03em;
  background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;display:block;margin-bottom:14px;line-height:1}
.appr h3{font-size:21px;font-weight:600;letter-spacing:-.01em;margin-bottom:10px}
.appr p{font-size:15.5px;color:var(--ink-soft);line-height:1.6}
@media(max-width:760px){.appr-grid{grid-template-columns:1fr}.appr{padding-bottom:8px;border-bottom:1px solid var(--line)}}

/* ====================================================================
   CONTACT
   ================================================================= */
.contact{background:var(--navy);color:#fff;overflow:hidden;text-align:center}
.contact-aurora .b1{width:50vw;height:50vw;left:-10vw;top:-16vw;background:radial-gradient(circle,#0a5bd6,transparent 68%);opacity:.6;animation:float1 20s var(--ease) infinite}
.contact-aurora .b2{width:44vw;height:44vw;right:-8vw;bottom:-18vw;background:radial-gradient(circle,#26d3ff,transparent 68%);opacity:.45;animation:float2 24s var(--ease) infinite}
.contact-wrap{position:relative;z-index:2}
.contact-title{font-size:clamp(34px,6vw,68px);font-weight:700;letter-spacing:-.03em;line-height:1.05;margin-bottom:18px}
.contact-lead{font-size:clamp(16px,2.2vw,21px);color:rgba(255,255,255,.78);max-width:46ch;margin:0 auto 40px}
.contact-qr{display:flex;flex-direction:column;align-items:center;gap:15px;margin-bottom:34px}
.qr-card{background:#fff;border-radius:24px;padding:14px;width:min(244px,64vw);box-shadow:0 24px 60px rgba(0,0,0,.34)}
.qr-card img{width:100%;height:auto;display:block;border-radius:12px}
.qr-cap{font-size:14.5px;color:rgba(255,255,255,.82);letter-spacing:.01em}
.contact-methods{display:flex;gap:12px;justify-content:center;align-items:center;flex-wrap:wrap}
.cm-or{font-size:14.5px;color:rgba(255,255,255,.6)}
.cm{padding:13px 28px;border-radius:100px;font-size:16px;font-weight:600;background:#fff;color:var(--navy);transition:.3s;border:1px solid transparent}
.cm:hover{transform:translateY(-3px);box-shadow:0 14px 36px rgba(0,0,0,.3)}

/* ====================================================================
   FOOTER
   ================================================================= */
.foot{background:var(--bg);padding:56px 0 64px;border-top:1px solid var(--line)}
.foot-inner{display:flex;flex-direction:column;align-items:center;text-align:center;gap:14px}
.foot-logo{height:48px;width:auto;opacity:.9}
.foot-tag{font-size:15px;color:var(--ink-soft);max-width:44ch}
.foot-copy{font-size:13px;color:var(--ink-faint)}

/* ====================================================================
   BUTTONS
   ================================================================= */
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  padding:14px 28px;border-radius:100px;font-size:16px;font-weight:600;
  cursor:pointer;transition:transform .3s var(--ease-out),box-shadow .3s,background .3s;
  border:1px solid transparent;font-family:var(--font);
}
.btn-primary{background:var(--blue);color:#fff;box-shadow:0 8px 24px rgba(0,113,227,.32)}
.btn-primary:hover{background:var(--blue-d);transform:translateY(-3px);box-shadow:0 14px 34px rgba(0,113,227,.42)}
.btn-ghost{background:transparent;color:var(--blue);border-color:rgba(0,113,227,.3)}
.btn-ghost:hover{background:rgba(0,113,227,.06);transform:translateY(-3px)}

/* ====================================================================
   SCROLL REVEAL (sections)
   ================================================================= */
.reveal{opacity:0;transform:translateY(34px);transition:opacity .9s var(--ease-out),transform .9s var(--ease-out)}
.reveal.in{opacity:1;transform:none}
/* slideshow handles its own reveal (overrides above when active) */

/* ====================================================================
   REDUCED MOTION
   ================================================================= */
@media(prefers-reduced-motion:reduce){
  *{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
  .reveal{opacity:1;transform:none}
  /* Keep the hero slideshow animated on phones in Low Power Mode (which reports
     reduced-motion). Autoplay is JS-driven and always runs; these restore the
     slide glide + active-slide entrance/zoom so mobile matches desktop. The
     infinite decorative aurora blobs stay disabled to save battery. */
  .show-track{transition-duration:.7s!important}
  .slide-prod.is-active .slide-bg{animation-duration:10s!important}
  .slide.is-active .reveal,.slide-prod.is-active .overlay-inner>*{animation-duration:.9s!important}
}