:root{
  --max-w:1200px;
  --space-2:8px;
  --space-3:12px;
  --space-4:16px;
  --space-6:24px;
  --space-8:32px;
  --space-12:48px;
  --radius-6:12px;
  --radius-10:20px;
  --shadow-1:0 4px 16px rgba(0,0,0,.08);
  --shadow-2:0 10px 30px rgba(41,98,255,.20);
  --c-bg:#F7F7F7;
  --c-bg-hero:#F7F7F7;
  --c-card:#FFFFFF;
  --c-txt:#272829;
  --c-sub:#707173;
  --c-primary:#15CCC0;
  --c-primary-2:rgba(21,204,192,.6);
  --header-h:68px;
  --mobile-menu-offset:56px;
  --nav-bg:rgba(255,255,255,.58);
  --nav-ink:#272829;
  --nav-ink-sub:rgba(39,40,41,.72);
  --accent-pink:#15CCC0;
  --primary-60:rgba(21,204,192,.6);
  --primary-50:rgba(21,204,192,.5);
  --primary-30:rgba(21,204,192,.3);
  --primary-14:rgba(21,204,192,.14);
  --ink-gray:#707173;
  --ink-light:#A2A3A5;
  --prompt:#FF3859;
}

/* 基础重置 */
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,"Apple Color Emoji","Segoe UI Emoji";
  color:var(--c-txt);
  background:linear-gradient(180deg,var(--c-bg-hero),var(--c-bg));
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font:inherit}

.container{max-width:var(--max-w);margin:0 auto;padding:0 var(--space-6)}
.section{padding:88px 0;scroll-margin-top:calc(var(--header-h) + 16px)}
.section__head{margin-bottom:var(--space-8)}
.section__head h2{margin:0 0 var(--space-3);font-size:32px}
.section__head p{margin:0;color:var(--c-sub)}

/* Header */
.site-header{position:sticky;top:0;z-index:20;background:var(--nav-bg);backdrop-filter:blur(8px);border-bottom:1px solid rgba(15,23,42,.05)}
.header-inner{height:var(--header-h);display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:10px;font-weight:700;color:var(--c-txt)}
.ph--app{width:32px;height:32px;border-radius:8px}
.app-icon{width:32px;height:32px;border-radius:8px;object-fit:cover;box-shadow:0 2px 6px rgba(0,0,0,.12)}

.nav ul{display:flex;gap:22px;list-style:none;margin:0;padding:0}
.nav a{position:relative;color:var(--nav-ink-sub);padding:10px 0;border-radius:0;letter-spacing:.01em;transition:color .2s ease, opacity .2s ease}
.nav a:hover{color:var(--nav-ink)}
.nav a::after{content:"";position:absolute;left:0;right:0;bottom:-10px;height:2px;background:currentColor;opacity:.28;transform:scaleX(0);transform-origin:left;border-radius:2px;transition:transform .25s ease, opacity .2s ease}
.nav a:hover::after{transform:scaleX(.6);opacity:.4}
.nav a.is-active{color:var(--nav-ink)}
.nav a.is-active::after{transform:scaleX(1);opacity:.5}

.nav-toggle{display:none;flex-direction:column;gap:5px;background:transparent;border:0;cursor:pointer}
.nav-toggle__bar{width:24px;height:2px;background:#111;border-radius:2px}

/* Hero */
.hero{padding-top:40px;background:radial-gradient(80% 80% at 0% 10%, rgba(156,193,255,.25), transparent 60%), radial-gradient(60% 60% at 100% 0%, rgba(255, 212, 219, .22), transparent 60%)}
.hero__inner{display:grid;grid-template-columns:1.1fr .9fr;gap:40px;align-items:center}
.hero__content .eyebrow{margin:0 0 var(--space-4);font-weight:600;color:#111;font-size:18px}
.highlight{position:relative;color:var(--c-txt)}
.highlight::after{content:"";position:absolute;left:0;right:0;bottom:-4px;height:10px;background:linear-gradient(90deg,transparent 0%,var(--c-primary-2) 30%,var(--c-primary) 100%);opacity:.35;border-radius:6px}
.hero__title{margin:8px 0 4px;font-size:54px;line-height:1.05}
.hero__subtitle{margin:0 0 var(--space-4);font-size:22px;color:var(--c-sub)}
.hero__desc{color:var(--c-sub);margin-bottom:var(--space-6)}

.hero__media{position:relative;min-height:520px}
.ph--phone{--rot:12deg;position:absolute;right:0;top:30px;width:min(46vw,320px);height:auto;border-radius:36px;box-shadow:var(--shadow-2);animation:floatY 6s ease-in-out infinite;object-fit:contain}
.ph--phone--secondary{--rot:-18deg;right:200px;top:120px;opacity:.95}

/* Scroll hint */
.scroll-hint{display:inline-flex;align-items:center;gap:8px;margin-top:16px;padding:8px 12px;border-radius:999px;background:rgba(255,255,255,.65);backdrop-filter:blur(6px);border:1px solid rgba(15,23,42,.08);color:var(--c-sub);font-size:14px;box-shadow:var(--shadow-1)}
.scroll-hint svg{color:var(--c-primary);width:18px;height:18px;animation:bounceDown 1.6s ease-in-out infinite;transform:rotate(180deg)}
.scroll-hint span{letter-spacing:.02em}

@keyframes bounceDown{0%,100%{transform:rotate(180deg) translateY(0);opacity:.95}50%{transform:rotate(180deg) translateY(6px);opacity:.75}}

/* 占位图通用样式 */
.ph{display:flex;align-items:center;justify-content:center;background:linear-gradient(180deg,#fff, #eef4ff);border:1px solid rgba(42,108,246,.20);color:#6b7280;border-radius:var(--radius-10);box-shadow:var(--shadow-1);text-shadow:0 1px 0 #fff}
.ph::after{content:attr(data-size);position:absolute;top:8px;right:8px;font-size:12px;color:#6b7280;background:rgba(255,255,255,.8);padding:2px 6px;border-radius:999px;border:1px solid rgba(0,0,0,.06)}
.ph--square{width:72px;height:72px;border-radius:20px}
.ph--wide{width:100%;height:420px;border-radius:28px}
.model-image{display:block;width:100%;height:auto;border-radius:28px;box-shadow:var(--shadow-1);object-fit:contain;background:#fff}
.ph--cube{width:min(42vw,480px);height:360px}
.about-image{display:block;width:100%;height:auto;border-radius:24px;box-shadow:var(--shadow-1);object-fit:contain;background:#fff}
.ph--qr{width:200px;height:200px;border-radius:14px}

/* Feature grid */
.features{position:relative;background:
  radial-gradient(70% 70% at 10% 0%, rgba(255, 210, 224, .28), transparent 60%),
  radial-gradient(60% 60% at 90% 0%, rgba(156,193,255,.32), transparent 60%),
  radial-gradient(30% 30% at 50% 10%, rgba(140,224,255,.18), transparent 70%),
  linear-gradient(180deg,#ffffff, #f7faff)}
.features__grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.feature-card{position:relative;background:linear-gradient(180deg,#ffffff,#f8fbff);border:1px solid rgba(15,23,42,.06);border-radius:24px;padding:22px;text-align:center;box-shadow:var(--shadow-1);overflow:hidden}
.feature-card > *{position:relative;z-index:1}
/* 渐变边框闪烁 */
.feature-card::before{content:"";position:absolute;inset:-1px;border-radius:inherit;padding:1px;background:conic-gradient(from 0deg, var(--c-primary), var(--accent-pink), #8ce0ff, var(--c-primary));-webkit-mask:linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude;animation:spin 6s linear infinite;opacity:.75}
/* 卡片内轻微彩色云层背景 */
.feature-card::after{content:"";position:absolute;inset:0;border-radius:calc(24px - 2px);background:radial-gradient(60% 60% at 30% 0%, rgba(156,193,255,.25), transparent 60%), radial-gradient(50% 40% at 80% 20%, rgba(255, 170, 200, .22), transparent 60%);z-index:0}
.feature-card__icon{margin:10px auto 14px}
.feature-icon{width:72px;height:72px;object-fit:contain;border-radius:16px;background:linear-gradient(180deg,#ffffff,#f3f7ff);box-shadow:var(--shadow-1);border:1px solid rgba(15,23,42,.06)}
.feature-card h3{margin:4px 0 6px}
.feature-card p{margin:0;color:var(--c-sub)}
@keyframes spin{to{transform:rotate(360deg)}}
@media (prefers-reduced-motion: reduce){.feature-card::before{animation:none}}

/* Reveal animation */
.reveal{opacity:0;filter:blur(6px);transform:translateY(26px);transition:opacity .6s cubic-bezier(.2,.7,.2,1), transform .6s cubic-bezier(.2,.7,.2,1), filter .6s}
.reveal.is-visible{opacity:1;transform:translateY(0);filter:blur(0)}
.reveal-l{transform:translateX(-36px);}
.reveal-l.is-visible{transform:translateX(0)}
.reveal-r{transform:translateX(36px);}
.reveal-r.is-visible{transform:translateX(0)}
.reveal-zoom{transform:scale(.94);}
.reveal-zoom.is-visible{transform:scale(1)}

/* 视差层（Hero/Model） */
.parallax{transform:translateY(var(--py,0));will-change:transform}

@keyframes floatY{
  0%,100%{ transform:rotate(var(--rot,0deg)) translateY(0) }
  50%{ transform:rotate(var(--rot,0deg)) translateY(-8px) }
}

/* Spotlight hover effect */
.fx-spotlight{position:relative;will-change:transform;transition:transform .15s ease, box-shadow .25s ease}
.fx-spotlight::before{content:"";position:absolute;inset:-1px;border-radius:inherit;background:radial-gradient(300px circle at var(--mx,50%) var(--my,50%), rgba(42,108,246,.18), transparent 40%);pointer-events:none;opacity:0;transition:opacity .2s ease}
.fx-spotlight:hover::before,.fx-spotlight:focus-visible::before{opacity:1}
.fx-spotlight.is-tilting{box-shadow:0 12px 30px rgba(42,108,246,.18)}

/* Buttons with spotlight */
.btn.fx-spotlight{overflow:hidden}
.btn.fx-spotlight::before{background:radial-gradient(140px circle at var(--mx,50%) var(--my,50%), rgba(255,255,255,.6), rgba(156,193,255,0) 60%)}

/* Model */
.model{position:relative;background:linear-gradient(180deg,#f4f9ff,#edf6ff)}
.model__bg{position:absolute;inset:0;background:radial-gradient(60% 60% at 50% 40%, rgba(42,108,246,.12), transparent 60%), radial-gradient(40% 30% at 80% 10%, rgba(156,193,255,.25), transparent 70%)}
.model__canvas{position:relative}

/* About */
.about{background:radial-gradient(70% 60% at 85% 10%, rgba(173,216,230,.25), transparent 60%), radial-gradient(60% 60% at 10% 0%, rgba(255,233,200,.24), transparent 60%), linear-gradient(180deg,#ffffff,#f6fbff)}
.about__inner{display:grid;grid-template-columns:1.1fr .9fr;gap:40px;align-items:center}
.about__content p{color:var(--c-sub)}

/* Footer */
/* Download QR */
.download{background:linear-gradient(180deg,#f7fbff,#eef5ff)}
.download__grid{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;align-items:start;justify-items:center}
.qr-card{background:#fff;border:1px solid rgba(15,23,42,.06);border-radius:16px;padding:16px 18px;text-align:center;box-shadow:var(--shadow-1);max-width:460px}
.qr-card h3{margin:10px 0 6px}
.qr-card p{margin:0;color:var(--c-sub)}
.link-cta{color:var(--c-primary);text-decoration:underline;text-underline-offset:3px}
.link-cta:hover{color:var(--nav-ink)}
.qr-card .ph--qr{display:block;margin:0 auto 10px}
.qr-card img.qr-img{display:block;margin:0 auto 10px;width:200px;height:200px;object-fit:contain;border-radius:14px}
.site-footer{background:#0b1425;color:#c9d4f3;padding:56px 0 24px;margin-top:20px}
.cta{display:flex;flex-direction:column;align-items:center;gap:16px;margin-bottom:28px}
.cta h3{margin:0;font-weight:700;line-height:1.2;background:linear-gradient(90deg,#ffffff, var(--c-primary));-webkit-background-clip:text;background-clip:text;color:transparent;text-shadow:0 0 18px rgba(21,204,192,.18)}
.cta__form{display:none}
.footer__meta{display:flex;flex-wrap:wrap;gap:10px;justify-content:space-between;align-items:center;border-top:1px solid rgba(255,255,255,.12);padding-top:16px;font-size:14px}
.footer__links{display:flex;gap:16px}
.footer__links a{color:#c9d4f3}

/* Buttons */
.btn{display:inline-flex;align-items:center;gap:8px;border:0;border-radius:999px;padding:12px 18px;font-weight:600;cursor:pointer}
.btn--primary{background:#15CCC0;color:#fff;box-shadow:0 8px 20px rgba(21,204,192,.35)}
.btn--secondary{background:#1f2a44;color:#fff}
.btn:active{transform:translateY(1px)}

/* Back to top */
.back-to-top{position:fixed;right:24px;bottom:24px;width:44px;height:44px;border-radius:999px;border:1px solid var(--primary-30);background:#15CCC0;color:#fff;box-shadow:0 10px 24px rgba(21,204,192,.35);cursor:pointer;display:none;transition:transform .18s ease, box-shadow .2s ease}
.back-to-top:hover{transform:translateY(-2px);box-shadow:0 14px 30px rgba(21,204,192,.45)}
.back-to-top:active{transform:translateY(0)}
.back-to-top:focus-visible{outline:2px solid var(--primary-50);outline-offset:2px}
.back-to-top.is-show{display:block}

/* Toast */
.toast,.toast--error{display:none}

/* Responsive */
@media (max-width: 1024px){
  .hero__inner{grid-template-columns:1fr;gap:24px}
  .hero__media{min-height:460px}
  .ph--phone{right:24px}
  .ph--phone--secondary{right:160px}
  .about__inner{grid-template-columns:1fr}
}

@media (max-width: 860px){
  .features__grid{grid-template-columns:repeat(2,1fr)}
  .hero__title{font-size:44px}
  .download__grid{grid-template-columns:1fr}
}

@media (max-width: 640px){
  .section{padding:64px 0}
  .features__grid{grid-template-columns:1fr}
  .ph--phone{position:relative;right:auto;top:auto;width:100%;height:auto;max-height:460px}
  .ph--phone--secondary{display:none}

  .nav-toggle{display:flex}
  .nav{position:fixed;inset:var(--mobile-menu-offset) 0 auto 0;background:#fff;border-bottom:1px solid rgba(15,23,42,.06);transform:translateY(calc(-100% - 8px));opacity:0;visibility:hidden;pointer-events:none;transition:transform .25s ease, opacity .2s ease;}
  .nav ul{flex-direction:column;gap:0}
  .nav li{border-top:1px solid rgba(15,23,42,.06)}
  .nav a{display:block;padding:14px var(--space-6)}
  .nav a::after{display:none}
  body.menu-open .nav{transform:translateY(0);opacity:1;visibility:visible;pointer-events:auto}
}