/* ============ InternSphere · shared design system ============ */
:root{
  --ink:#081626; --ink2:#0C2444; --ink3:#060F1B;
  --gold:#C9A66B; --gold-bright:#E7CE95; --gold-deep:#A9854B;
  --teal:#9BD0D6; --teal2:#6FA8B0;
  --paper:#F3EFE5; --soft:#DCE3EC; --dim:#A9B6C7; --faint:#7C8A9C;
  --hair:rgba(201,166,107,.30); --hair2:rgba(255,255,255,.09);
  --card:rgba(155,208,214,.05); --cardln:rgba(155,208,214,.16);
  --maxw:1180px;
  --nav-h:74px;
  --ease:cubic-bezier(.4,0,.2,1);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:'Manrope','Noto Sans SC',system-ui,sans-serif;
  color:var(--paper);background:var(--ink3);line-height:1.6;
  overflow-x:hidden;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 28px}

/* ---- bilingual visibility ---- */
html[data-lang="en"] .zh{display:none!important}
html[data-lang="zh"] .en{display:none!important}

/* ---- typography helpers ---- */
.serif{font-family:'Fraunces',Georgia,serif}
.serif-cn{font-family:'Noto Serif SC',serif}
.kicker{font-size:12px;letter-spacing:.28em;text-transform:uppercase;color:var(--teal);font-weight:700}
.gold{color:var(--gold-bright)}
.eyebrow{display:inline-block;font-size:11px;letter-spacing:.22em;text-transform:uppercase;color:var(--gold);
  border:1px solid var(--hair);border-radius:30px;padding:6px 16px;font-weight:600}
h1,h2,h3{line-height:1.12;font-weight:800}
.h-xl{font-size:clamp(38px,6vw,68px);font-weight:800;letter-spacing:.01em}
.h-lg{font-size:clamp(30px,4.4vw,46px);font-weight:800}
.h-md{font-size:clamp(24px,3.2vw,32px);font-weight:800}
.lead{font-size:clamp(15px,1.6vw,18px);color:var(--soft);line-height:1.85}
.muted{color:var(--dim)}
.faint{color:var(--faint)}

/* ---- buttons ---- */
.btn{display:inline-flex;align-items:center;gap:9px;font-weight:700;font-size:14px;
  padding:13px 26px;border-radius:40px;cursor:pointer;border:1px solid transparent;
  transition:.25s var(--ease);white-space:nowrap}
.btn-gold{background:linear-gradient(180deg,var(--gold-bright),var(--gold));color:#21160a}
.btn-gold:hover{transform:translateY(-2px);box-shadow:0 10px 30px rgba(201,166,107,.30)}
.btn-ghost{border-color:var(--hair);color:var(--paper)}
.btn-ghost:hover{border-color:var(--gold);color:var(--gold-bright)}
.btn-sm{padding:10px 18px;font-size:13px}

/* ============ NAV ============ */
.nav{position:fixed;top:0;left:0;right:0;height:var(--nav-h);z-index:100;
  display:flex;align-items:center;transition:.3s var(--ease);
  background:rgba(8,18,30,0);backdrop-filter:blur(0)}
.nav.scrolled{background:rgba(8,18,30,.92);backdrop-filter:blur(14px);
  border-bottom:1px solid var(--hair2);height:64px}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;width:100%}
.brand{display:flex;align-items:center;gap:11px}
.brand img{height:34px;width:auto}
.brand .wm{font-family:'Fraunces',serif;font-weight:560;font-size:18px;color:var(--paper)}
.brand .wm b{color:var(--gold-bright)}
.brand .wm .sub{font-family:'Noto Serif SC',serif;font-size:11px;color:var(--gold);margin-left:6px;font-weight:600}
.navlinks{display:flex;align-items:center;gap:28px}
.navlinks a{font-size:14px;font-weight:600;color:var(--soft);position:relative;padding:4px 0;transition:.2s}
.navlinks a:hover,.navlinks a.active{color:var(--gold-bright)}
.navlinks a.active:after{content:"";position:absolute;left:0;right:0;bottom:-4px;height:2px;background:var(--gold)}
.nav-cta-mobile{display:none}
.navtools{display:flex;align-items:center;gap:16px}
.langtoggle{display:flex;align-items:center;font-size:13px;font-weight:700;border:1px solid var(--hair2);
  border-radius:30px;overflow:hidden}
.langtoggle button{background:none;border:none;color:var(--faint);padding:6px 12px;cursor:pointer;font-weight:700;font-size:12px}
.langtoggle button.on{background:var(--gold);color:#21160a}
.burger{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:6px}
.burger span{width:24px;height:2px;background:var(--paper);transition:.3s}

/* ============ HERO ============ */
.hero{position:relative;min-height:88vh;display:flex;align-items:center;overflow:hidden;
  background:radial-gradient(120% 90% at 80% 10%,#0C2444 0%,#081626 55%,#060F1B 100%)}
.hero .sphere{position:absolute;right:-10%;top:50%;transform:translateY(-50%);
  width:min(70vw,760px);aspect-ratio:1;opacity:.5;pointer-events:none}
.hero-inner{position:relative;z-index:2;max-width:760px;padding-top:var(--nav-h)}
.hero .gold-line{width:56px;height:2px;background:var(--gold);margin-bottom:26px}
.hero h1{margin:18px 0}
.hero .lead{max-width:620px;margin-top:16px}
.hero .cta-row{display:flex;gap:14px;margin-top:34px;flex-wrap:wrap}
.hero-tags{display:flex;gap:10px;margin-top:30px;flex-wrap:wrap}
.hero-tags span{font-size:12.5px;color:var(--soft);border:1px solid var(--hair);border-radius:30px;padding:7px 16px}

/* sphere wireframe stroke */
.sphere circle,.sphere ellipse,.sphere line{fill:none;stroke:var(--gold);stroke-width:.6;opacity:.30;vector-effect:non-scaling-stroke}

/* ============ SECTIONS ============ */
section{position:relative}
.sec{padding:clamp(64px,9vw,110px) 0}
.sec-head{max-width:760px;margin-bottom:46px}
.sec-head .kicker{margin-bottom:16px;display:block}
.sec-head h2{margin-bottom:16px}
.sec.alt{background:linear-gradient(180deg,#0C2444,#0A1B30)}
.center{text-align:center;margin-left:auto;margin-right:auto}

/* grids */
.grid{display:grid;gap:20px}
.g2{grid-template-columns:repeat(2,1fr)}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}

/* cards */
.card{background:var(--card);border:1px solid var(--cardln);border-radius:16px;padding:28px 24px;
  transition:.3s var(--ease)}
.card:hover{border-color:var(--hair);transform:translateY(-4px);background:rgba(155,208,214,.08)}
.card .num{font-family:'Fraunces',serif;font-size:30px;color:var(--teal);line-height:1;font-weight:500}
.card .cl{font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--teal);font-weight:700}
.card h3{font-size:20px;margin:12px 0 6px;color:#fff;font-weight:700}
.card .en-sub{font-family:'Fraunces',serif;font-style:italic;font-size:14px;color:var(--gold);margin-bottom:10px}
.card p{font-size:14px;color:var(--dim);line-height:1.7}
.card p b,.card.feature p b{color:var(--gold-bright)}
.card.feature{border-color:var(--gold);background:rgba(201,166,107,.07)}
.card.feature.bright{border:1.6px solid var(--gold-bright);background:rgba(201,166,107,.10)}

/* stat row */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:0;border-top:1px solid var(--hair);
  border-bottom:1px solid var(--hair)}
.stat{padding:34px 14px;text-align:center;border-right:1px solid var(--hair2)}
.stat:last-child{border-right:0}
.stat .n{font-family:'Fraunces',serif;font-weight:500;font-size:clamp(32px,4.4vw,46px);color:var(--gold-bright);line-height:1}
.stat .t{font-size:13px;color:var(--soft);margin-top:12px}
.stat .s{font-size:11px;color:var(--faint);margin-top:6px}

/* callout */
.callout{background:rgba(201,166,107,.07);border-left:3px solid var(--gold);border-radius:0 12px 12px 0;
  padding:22px 28px;font-size:15px;color:var(--soft);line-height:1.75}
.callout b{color:var(--gold-bright)}

/* list */
ul.dot{list-style:none}
ul.dot li{padding-left:24px;position:relative;margin-bottom:15px;font-size:15px;color:var(--soft);line-height:1.65}
ul.dot li:before{content:"";position:absolute;left:0;top:9px;width:7px;height:7px;border-radius:50%;background:var(--teal)}
ul.dot li b{color:var(--gold-bright)}

/* table */
.tablewrap{overflow-x:auto;border:1px solid var(--hair2);border-radius:14px}
table{width:100%;border-collapse:collapse;font-size:14px;min-width:620px}
th,td{text-align:left;padding:16px 18px;border-bottom:1px solid var(--hair2);vertical-align:top}
th{color:var(--teal);font-size:11px;letter-spacing:.08em;text-transform:uppercase;font-weight:700;background:rgba(155,208,214,.04)}
td{color:var(--soft)}td b{color:var(--gold-bright)}
tr td:first-child{color:var(--dim);font-weight:600}
tr:last-child td{border-bottom:0}

/* tabs (for source-mechanism etc.) */
.tabs{display:flex;gap:10px;margin-bottom:24px;flex-wrap:wrap}
.tab{padding:10px 22px;border:1px solid var(--hair);border-radius:30px;cursor:pointer;font-size:13px;
  font-weight:700;color:var(--dim);transition:.2s}
.tab.on{background:var(--gold);color:#21160a;border-color:var(--gold)}
.tabpane{display:none}.tabpane.on{display:block;animation:fade .4s var(--ease)}
@keyframes fade{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* steps */
.step{display:flex;gap:22px;padding:24px 0;border-bottom:1px solid var(--hair2)}
.step:last-child{border-bottom:0}
.step .sn{font-family:'Fraunces',serif;font-weight:500;font-size:30px;color:var(--teal);min-width:54px;line-height:1.1}
.step h4{font-size:18px;color:#fff;font-weight:700}
.step h4 .en-sub{font-family:'Fraunces',serif;font-style:italic;font-size:13px;color:var(--gold);margin-left:10px;font-weight:400}
.step p{font-size:14px;color:var(--dim);margin-top:8px;line-height:1.7}
.step p b{color:var(--gold-bright)}

/* faq accordion */
.faq{border-top:1px solid var(--hair2)}
.faq details{border-bottom:1px solid var(--hair2)}
.faq summary{list-style:none;cursor:pointer;padding:22px 0;display:flex;justify-content:space-between;
  align-items:center;gap:20px;font-family:'Noto Serif SC',serif;font-weight:600;font-size:17px;color:#fff}
.faq summary::-webkit-details-marker{display:none}
.faq summary .pm{color:var(--gold);font-size:24px;transition:.3s;flex-shrink:0;line-height:1}
.faq details[open] summary .pm{transform:rotate(45deg)}
.faq details p{padding:0 0 24px;font-size:14.5px;color:var(--dim);line-height:1.8;max-width:820px}

/* quotes */
.quote{border-left:2px solid var(--teal2);background:rgba(155,208,214,.04);border-radius:0 12px 12px 0;padding:22px 24px}
.quote p{font-size:14.5px;color:var(--soft);line-height:1.7}
.quote .by{font-size:12px;color:var(--gold);margin-top:12px;font-weight:700}

/* split entry cards (homepage) */
.entry{position:relative;border:1px solid var(--cardln);border-radius:20px;padding:44px 38px;overflow:hidden;
  transition:.35s var(--ease);min-height:340px;display:flex;flex-direction:column;justify-content:flex-end;background:rgba(12,36,68,.5)}
.entry:hover{transform:translateY(-6px);border-color:var(--gold)}
.entry .sphere{position:absolute;right:-30%;top:-20%;width:60%;opacity:.4}
.entry .eyebrow{margin-bottom:18px}
.entry h3{font-size:30px;color:#fff;margin-bottom:10px}
.entry .en-sub{font-family:'Fraunces',serif;font-style:italic;color:var(--gold);font-size:16px;margin-bottom:14px}
.entry p{color:var(--dim);font-size:14.5px;line-height:1.7;margin-bottom:22px}
.entry .go{color:var(--gold-bright);font-weight:700;font-size:14px;display:inline-flex;gap:8px;align-items:center}
.entry:hover .go{gap:14px}

/* page hero (sub pages, shorter) */
.pagehero{position:relative;padding:calc(var(--nav-h) + 70px) 0 60px;overflow:hidden;
  background:radial-gradient(120% 100% at 85% 0%,#0C2444,#081626 60%,#060F1B)}
.pagehero .sphere{position:absolute;right:-12%;top:-30%;width:min(60vw,620px);opacity:.4}
.pagehero h1{margin:14px 0 16px}
.pagehero .lead{max-width:680px}
.breadcrumb{font-size:12px;color:var(--faint);letter-spacing:.04em;margin-bottom:6px}
.breadcrumb a:hover{color:var(--gold)}

/* team circle */
.teamwrap{max-width:760px;margin:0 auto}

/* ============ FOOTER ============ */
.footer{background:var(--ink3);border-top:1px solid var(--hair2);padding:64px 0 34px}
.footer .cols{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.2fr;gap:40px}
.footer .brand{margin-bottom:18px}
.footer p.about{font-size:13.5px;color:var(--dim);line-height:1.7;max-width:300px}
.footer h5{font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--teal);margin-bottom:18px;font-weight:700}
.footer a.fl{display:block;font-size:13.5px;color:var(--soft);margin-bottom:11px;transition:.2s}
.footer a.fl:hover{color:var(--gold-bright)}
.footer .contact a{display:block;font-size:13.5px;color:var(--soft);margin-bottom:10px}
.footer .contact a:hover{color:var(--gold-bright)}
.footer .bottom{border-top:1px solid var(--hair2);margin-top:48px;padding-top:24px;display:flex;
  justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap;font-size:12px;color:var(--faint)}

/* ============ CTA band ============ */
.ctaband{background:linear-gradient(120deg,#0C2444,#0A1B33);border:1px solid var(--hair);border-radius:22px;
  padding:clamp(40px,6vw,64px);text-align:center;position:relative;overflow:hidden}
.ctaband .sphere{position:absolute;right:-14%;top:-40%;width:46%;opacity:.4}
.ctaband h2{margin-bottom:14px}
.ctaband .lead{max-width:560px;margin:0 auto 28px}

/* ============ MODAL (book a demo) ============ */
.modal{position:fixed;inset:0;z-index:200;display:none;align-items:center;justify-content:center;padding:20px;
  background:rgba(4,9,16,.7);backdrop-filter:blur(6px)}
.modal.open{display:flex;animation:fade .3s var(--ease)}
.modal-box{background:linear-gradient(165deg,#0E2A4A,#081626);border:1px solid var(--hair);border-radius:20px;
  padding:40px;max-width:480px;width:100%;position:relative}
.modal-box .x{position:absolute;top:18px;right:20px;background:none;border:none;color:var(--faint);font-size:26px;cursor:pointer;line-height:1}
.modal-box .x:hover{color:var(--gold)}
.modal-box h3{font-size:24px;color:#fff;margin-bottom:8px}
.modal-box .lead{font-size:14px;margin-bottom:24px}
.field{margin-bottom:16px}
.field label{display:block;font-size:12px;letter-spacing:.04em;color:var(--teal);margin-bottom:7px;font-weight:600}
.field input,.field select,.field textarea{width:100%;background:rgba(155,208,214,.06);border:1px solid var(--hair2);
  border-radius:10px;padding:12px 14px;color:var(--paper);font-size:14px;font-family:inherit;transition:.2s}
.field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--gold)}
.field input::placeholder,.field textarea::placeholder{color:var(--faint)}
.modal .btn{width:100%;justify-content:center;margin-top:6px}
.modal .privacy{font-size:11px;color:var(--faint);text-align:center;margin-top:14px;line-height:1.6}
.modal .thanks{display:none;text-align:center;padding:20px 0}
.modal .thanks .ic{font-size:46px;color:var(--gold);margin-bottom:14px}

/* reveal on scroll */
html:not(.js) .reveal{opacity:1!important;transform:none!important}
.reveal{opacity:0;transform:translateY(24px);transition:.7s var(--ease)}
.reveal.in{opacity:1;transform:none}

/* ============ RESPONSIVE ============ */
@media(max-width:920px){
  .footer .cols{grid-template-columns:1fr 1fr}
  .g4{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:760px){
  .navlinks{position:fixed;top:0;right:0;height:100vh;width:78%;max-width:320px;background:rgba(8,18,30,.98);
    backdrop-filter:blur(16px);flex-direction:column;align-items:flex-start;justify-content:center;gap:26px;
    padding:40px;transform:translateX(100%);transition:.35s var(--ease);border-left:1px solid var(--hair2)}
  .navlinks.open{transform:translateX(0)}
  .navlinks a{font-size:19px}
  .burger{display:flex}
  .navtools .langtoggle{display:flex}
  .nav-cta-desktop{display:none}
  .nav-cta-mobile{display:inline-flex}
  .g2,.g3,.g4{grid-template-columns:1fr}
  .stats{grid-template-columns:repeat(2,1fr)}
  .stat{border-bottom:1px solid var(--hair2)}
  .footer .cols{grid-template-columns:1fr;gap:30px}
  .step{flex-direction:column;gap:8px}
  .hero{min-height:auto;padding:120px 0 70px}
}