/* ============================================================
   SciArtWorks 科艺 — portal · LIGHT gallery theme
   Science × Art · dependency-free · bilingual · Cloudflare Pages
   ============================================================ */

:root{
  --bg:#f7f5f0;          /* warm off-white */
  --bg-soft:#fffdf8;     /* sections / cards */
  --card:#ffffff;
  --ink:#16131c;         /* near-black, warm */
  --ink-soft:#403b4c;
  --muted:#6c6678;
  --muted-2:#9a93a6;
  --line:rgba(22,19,28,.10);
  --line-2:rgba(22,19,28,.06);

  --music:#6b3df0;
  --dance:#e23d6b;
  --robot:#0bbfa6;
  --vfx:#e0901e;

  --spectrum:linear-gradient(100deg,#6b3df0 0%,#e23d6b 38%,#0bbfa6 70%,#e0901e 100%);

  --maxw:1180px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --r:18px;
  --font:"Inter","Segoe UI",system-ui,-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);
  font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;overflow-x:hidden}

a{color:inherit;text-decoration:none}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.container{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:clamp(20px,5vw,40px)}
.skip-link{position:absolute;left:-9999px;top:0;background:var(--ink);color:#fff;padding:10px 16px;z-index:1000;border-radius:0 0 8px 0}
.skip-link:focus{left:0}

/* lang visibility */
:lang(zh-CN) [lang="en"]{display:none}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:.5em;padding:.85em 1.5em;border-radius:100px;font-weight:600;font-size:.98rem;
  border:1px solid transparent;cursor:pointer;transition:transform .25s var(--ease),box-shadow .3s var(--ease),background .3s,border-color .3s;will-change:transform}
.btn:active{transform:translateY(1px) scale(.99)}
.btn-primary{color:#fff;background:var(--ink);box-shadow:0 10px 26px -12px rgba(22,19,28,.6)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 18px 40px -14px rgba(107,61,240,.5)}
.btn-ghost{color:var(--ink);border-color:var(--line);background:transparent}
.btn-ghost:hover{border-color:var(--ink);transform:translateY(-2px)}
.btn-lg{font-size:1.08rem;padding:1em 1.9em}

/* ---------- header / nav ---------- */
.site-header{position:fixed;top:0;left:0;right:0;z-index:100;transition:background .35s,border-color .35s,backdrop-filter .35s;border-bottom:1px solid transparent}
.site-header.scrolled{background:rgba(247,245,240,.78);backdrop-filter:blur(16px) saturate(140%);border-bottom-color:var(--line)}
.nav{display:flex;align-items:center;justify-content:space-between;height:74px}
.brand{display:flex;align-items:center;gap:.55em;font-weight:700;letter-spacing:-.01em}
.brand-logo{height:38px;width:auto;display:block;filter:drop-shadow(0 5px 12px rgba(63,99,221,.22))}
.footer-brand-row{display:flex;align-items:center;gap:.55em}
.footer-brand-row .brand-logo{height:30px}
.brand-text{font-size:1.12rem}
.brand-cn{margin-left:.45em;font-size:.7em;color:var(--muted);font-weight:500;letter-spacing:.08em}
.brand-cn:empty{display:none}

.nav-menu{display:flex;align-items:center;gap:clamp(16px,2.2vw,30px);list-style:none;margin:0;padding:0}
.nav-menu a{font-size:.95rem;color:var(--muted);font-weight:500;transition:color .2s;position:relative}
.nav-menu a:hover{color:var(--ink)}
.nav-menu a:not(.nav-cta)::after{content:"";position:absolute;left:0;bottom:-6px;width:0;height:2px;background:var(--spectrum);transition:width .3s var(--ease)}
.nav-menu a:not(.nav-cta):hover::after{width:100%}
.nav-cta{padding:.55em 1.1em;border:1px solid var(--line);border-radius:100px;color:var(--ink)!important}
.nav-cta:hover{border-color:var(--ink)}
.lang-toggle{font-family:inherit;font-size:.82rem;font-weight:700;letter-spacing:.06em;color:var(--ink);
  background:transparent;border:1px solid var(--line);border-radius:100px;padding:.5em .9em;cursor:pointer;transition:border-color .2s,background .2s}
.lang-toggle:hover{border-color:var(--ink)}

.nav-toggle{display:none;flex-direction:column;gap:5px;width:42px;height:42px;align-items:center;justify-content:center;background:none;border:1px solid var(--line);border-radius:12px;cursor:pointer}
.nav-toggle span{width:18px;height:2px;background:var(--ink);border-radius:2px;transition:transform .3s,opacity .3s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* ---------- hero ---------- */
.hero{position:relative;padding-top:120px;padding-bottom:60px;overflow:hidden}
.hero::before{content:"";position:absolute;inset:0;z-index:-1;
  background:
    radial-gradient(50% 50% at 80% 12%,rgba(107,61,240,.10),transparent 60%),
    radial-gradient(45% 45% at 92% 40%,rgba(226,61,107,.08),transparent 60%),
    radial-gradient(50% 40% at 70% 80%,rgba(11,191,166,.07),transparent 60%)}
.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:clamp(28px,5vw,64px);align-items:center;min-height:calc(100svh - 200px)}
.eyebrow{display:inline-block;font-size:.82rem;letter-spacing:.14em;color:var(--muted);font-weight:600;
  margin:0 0 22px;padding:.5em 1.1em;border:1px solid var(--line);border-radius:100px;background:var(--bg-soft)}
.eyebrow i{font-style:italic;font-family:Georgia,"Times New Roman",serif;color:var(--ink);letter-spacing:.02em}
.hero-title{font-size:clamp(2.6rem,6.6vw,5.4rem);line-height:1.04;letter-spacing:-.035em;font-weight:800;margin:0 0 26px;max-width:14ch}
.grad{background:var(--spectrum);-webkit-background-clip:text;background-clip:text;color:transparent;background-size:200% auto;animation:hue 9s linear infinite}
.grad-line{position:relative;white-space:nowrap}
.grad-line::after{content:"";position:absolute;left:0;right:0;bottom:.04em;height:.08em;background:var(--spectrum);border-radius:2px}
@keyframes hue{to{background-position:200% center}}
.hero-sub{font-size:clamp(1.05rem,1.5vw,1.28rem);color:var(--muted);max-width:48ch;margin:0 0 34px;line-height:1.72}
.hero-sub b{color:var(--ink);font-weight:600}
.hero-actions{display:flex;flex-wrap:wrap;gap:14px}

.hero-art{display:flex;justify-content:center;align-items:center}
.hero-svg{width:100%;max-width:480px;height:auto;filter:drop-shadow(0 30px 60px rgba(107,61,240,.14))}
.hero-svg .orbit{transform-origin:240px 220px;animation:spin 60s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}

/* ---------- statement ---------- */
.statement-sec{padding:clamp(48px,7vw,96px) 0;border-block:1px solid var(--line-2);background:var(--bg-soft)}
.statement{font-size:clamp(1.5rem,3.4vw,2.5rem);line-height:1.4;letter-spacing:-.02em;font-weight:600;max-width:24ch;margin:0 auto;text-align:center;color:var(--ink)}
.statement em{font-style:normal;background:var(--spectrum);-webkit-background-clip:text;background-clip:text;color:transparent}

/* ---------- sections ---------- */
.section{position:relative;padding:clamp(76px,10vw,140px) 0}
.section-soft{background:var(--bg-soft)}
.section-head{max-width:62ch;margin:0 0 clamp(42px,6vw,70px)}
.section-kicker{font-size:.8rem;letter-spacing:.16em;color:var(--music);font-weight:700;margin:0 0 16px}
.section-title{font-size:clamp(1.9rem,4.2vw,3.1rem);line-height:1.1;letter-spacing:-.03em;font-weight:800;margin:0 0 18px}
.section-intro{font-size:clamp(1rem,1.4vw,1.16rem);color:var(--muted);margin:0;line-height:1.7}

/* ---------- practice ---------- */
.practice-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:18px}
.pcard{position:relative;padding:30px 26px 32px;border-radius:var(--r);background:var(--card);border:1px solid var(--line);
  box-shadow:0 1px 0 rgba(22,19,28,.02);transition:transform .35s var(--ease),box-shadow .35s,border-color .35s}
.pcard[data-accent="music"]{--ac:var(--music)} .pcard[data-accent="dance"]{--ac:var(--dance)}
.pcard[data-accent="robot"]{--ac:var(--robot)} .pcard[data-accent="vfx"]{--ac:var(--vfx)}
.pcard:hover{transform:translateY(-6px);box-shadow:0 22px 40px -22px rgba(22,19,28,.28);border-color:color-mix(in srgb,var(--ac) 40%,var(--line))}
.p-ic{display:grid;place-items:center;width:50px;height:50px;border-radius:14px;color:var(--ac);
  background:color-mix(in srgb,var(--ac) 12%,#fff);margin-bottom:18px}
.p-ic svg{width:26px;height:26px}
.pcard h3{font-size:1.3rem;margin:0;letter-spacing:-.01em}
.p-en{margin:.2em 0 .8em;font-size:.74rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--ac)}
.p-d{color:var(--muted);font-size:.96rem;margin:0;line-height:1.62}

/* ---------- universe / domains ---------- */
.domain-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px}
.domain{position:relative;padding:28px 24px;border-radius:var(--r);background:var(--card);border:1px solid var(--line);
  overflow:hidden;transition:transform .4s var(--ease),box-shadow .4s,border-color .4s}
.domain[data-accent="music"]{--ac:var(--music)} .domain[data-accent="dance"]{--ac:var(--dance)}
.domain[data-accent="robot"]{--ac:var(--robot)} .domain[data-accent="vfx"]{--ac:var(--vfx)}
.domain::after{content:"";position:absolute;width:160px;height:160px;top:-70px;right:-70px;border-radius:50%;
  background:radial-gradient(circle,color-mix(in srgb,var(--ac) 30%,transparent),transparent 70%);opacity:0;transition:opacity .45s}
.domain:hover{transform:translateY(-6px);box-shadow:0 22px 40px -24px rgba(22,19,28,.3);border-color:color-mix(in srgb,var(--ac) 45%,var(--line))}
.domain:hover::after{opacity:1}
.d-ic{display:grid;place-items:center;width:48px;height:48px;border-radius:13px;color:var(--ac);
  background:color-mix(in srgb,var(--ac) 12%,#fff);margin-bottom:18px}
.d-ic svg{width:26px;height:26px}
.domain h3{font-size:1.3rem;margin:0;letter-spacing:-.01em}
.d-en{margin:.2em 0 .8em;font-size:.74rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--ac)}
.d-line{margin:0;color:var(--muted);font-size:.94rem}
.domain-more{margin:clamp(28px,4vw,44px) 0 0;text-align:center;color:var(--muted-2);font-size:1rem;letter-spacing:.02em}

/* ---------- about ---------- */
.about-wrap{display:grid;grid-template-columns:1.25fr .75fr;gap:clamp(32px,5vw,64px);align-items:center}
.about-lead{color:var(--muted);font-size:1.08rem;line-height:1.8;margin:0 0 34px;max-width:54ch}
.about-stats{display:flex;flex-wrap:wrap;gap:clamp(24px,4vw,52px)}
.about-stats div{display:flex;flex-direction:column}
.about-stats strong{font-size:clamp(2rem,4vw,2.8rem);font-weight:800;letter-spacing:-.03em;background:var(--spectrum);-webkit-background-clip:text;background-clip:text;color:transparent}
.about-stats span{font-size:.9rem;color:var(--muted)}
.about-art{display:flex;justify-content:center}
.about-svg{width:100%;max-width:320px;height:auto}

/* ---------- contact ---------- */
.section-cta{text-align:center}
.cta-inner{max-width:680px;margin-inline:auto;padding:clamp(40px,6vw,68px) clamp(24px,5vw,56px);border-radius:28px;
  background:radial-gradient(120% 120% at 50% 0,rgba(107,61,240,.08),transparent 60%),var(--card);border:1px solid var(--line);
  box-shadow:0 30px 60px -40px rgba(22,19,28,.4)}
.cta-kicker{margin-bottom:14px}
.cta-inner h2{font-size:clamp(1.7rem,3.6vw,2.6rem);letter-spacing:-.03em;margin:0 0 14px;font-weight:800}
.cta-sub{color:var(--muted);margin:0 0 32px;font-size:1.05rem}
.contact-form{text-align:left}
.cf-row{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.cf-field{display:block;margin-bottom:16px}
.cf-field>span{display:block;font-size:.85rem;color:var(--muted);margin-bottom:8px;font-weight:600}
.cf-field input,.cf-field textarea{width:100%;font-family:inherit;font-size:1rem;color:var(--ink);background:var(--bg-soft);
  border:1px solid var(--line);border-radius:12px;padding:.8em .95em;transition:border-color .2s,box-shadow .2s;resize:vertical}
.cf-field input::placeholder,.cf-field textarea::placeholder{color:var(--muted-2)}
.cf-field input:focus,.cf-field textarea:focus{outline:none;border-color:var(--music);box-shadow:0 0 0 3px color-mix(in srgb,var(--music) 18%,transparent)}
.cf-hp{position:absolute;left:-9999px;width:1px;height:1px;opacity:0}
.cf-actions{display:flex;align-items:center;gap:18px;flex-wrap:wrap;margin-top:6px}
.cf-status{margin:0;font-size:.92rem;color:var(--muted)}
.cf-status.ok{color:var(--robot)}
.cf-status.err{color:var(--dance)}
.contact-form.sending .btn-primary{opacity:.6;pointer-events:none}

/* ---------- footer ---------- */
.site-footer{border-top:1px solid var(--line);padding:56px 0 36px;background:var(--bg-soft)}
.footer-inner{display:flex;flex-wrap:wrap;gap:32px;justify-content:space-between;align-items:flex-start;margin-bottom:36px}
.footer-brand p{color:var(--muted);margin:.6em 0 0;font-size:.95rem}
.footer-nav{display:flex;flex-wrap:wrap;gap:22px}
.footer-nav a{color:var(--muted);font-size:.95rem;transition:color .2s}
.footer-nav a:hover{color:var(--ink)}
.footer-bottom{display:flex;flex-wrap:wrap;gap:12px;justify-content:space-between;color:var(--muted-2);font-size:.85rem;padding-top:24px;border-top:1px solid var(--line)}

/* ---------- reveal ---------- */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .8s var(--ease),transform .8s var(--ease)}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  .grad,.hero-svg .orbit{animation:none}
}

/* ---------- responsive ---------- */
@media (max-width:900px){
  .hero-grid{grid-template-columns:1fr;min-height:0;gap:24px}
  .hero-art{order:-1;max-width:380px;margin:0 auto}
  .about-wrap{grid-template-columns:1fr}
  .about-art{order:-1;max-width:240px}
}
@media (max-width:860px){
  .nav-toggle{display:flex}
  .nav-menu{position:fixed;inset:74px 0 auto 0;flex-direction:column;align-items:flex-start;gap:0;
    background:rgba(255,253,248,.98);backdrop-filter:blur(20px);border-bottom:1px solid var(--line);
    padding:8px 0;transform:translateY(-12px);opacity:0;pointer-events:none;transition:transform .3s var(--ease),opacity .3s}
  .nav-menu.open{transform:none;opacity:1;pointer-events:auto}
  .nav-menu li{width:100%}
  .nav-menu a{display:block;padding:16px clamp(20px,5vw,40px);width:100%}
  .nav-menu a:not(.nav-cta)::after{display:none}
  .nav-cta,.lang-toggle{margin:8px clamp(20px,5vw,40px);display:inline-block}
}
@media (max-width:520px){
  body{font-size:16px}
  .hero{padding-top:100px}
  .cf-row{grid-template-columns:1fr}
}
@media (min-width:1700px){:root{--maxw:1280px}}