:root{
  /* ----- DARK THEME (default — matches branding) ----- */
  --bg:#0a0b12;
  --bg-2:#0f1120;
  --panel:#13152a;
  --panel-2:#181b33;
  --ink:#eef0fb;
  --muted:#a3a7c4;
  --line:rgba(255,255,255,.08);
  --brand:#7c5cff;
  --brand-2:#22d3ee;
  --gold:#f4c46b;
  --radius:18px;
  --max:1180px;
  --font:'Sora','Noto Sans SC',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  /* surfaces / overlays that need to flip between themes */
  --nav-bg:rgba(10,11,18,.82);
  --img-bg:#1a1d33;
  --chip-bg:rgba(10,11,18,.78);
  --em-chip-bg:rgba(10,11,18,.82);
  --em-close-bg:rgba(10,11,18,.55);
  --em-body-ink:#c5c9e2;
  --link-hi:#5ee9ff;
  --grid-line:rgba(255,255,255,.04);
}
/* ----- LIGHT THEME ----- */
html[data-theme="light"]{
  --bg:#f6f7fb;
  --bg-2:#eceefb;
  --panel:#ffffff;
  --panel-2:#f1f2fa;
  --ink:#171a2e;
  --muted:#525879;
  --line:rgba(20,24,60,.12);
  --brand:#6a45f0;
  --brand-2:#0bb6cf;
  --nav-bg:rgba(255,255,255,.86);
  --img-bg:#e6e8f4;
  --chip-bg:rgba(255,255,255,.86);
  --em-chip-bg:rgba(255,255,255,.9);
  --em-close-bg:rgba(20,24,60,.06);
  --em-body-ink:#2c3050;
  --link-hi:#089bb4;
  --grid-line:rgba(20,24,60,.05);
}
html[data-theme="light"] body{color:var(--ink)}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);
  line-height:1.6;-webkit-font-smoothing:antialiased;overflow-x:hidden;
  transition:background-color .4s ease,color .4s ease;
}
html[data-lang="zh"] body{font-family:'Noto Sans SC','Sora',system-ui,sans-serif}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.container{width:100%;max-width:var(--max);margin:0 auto;padding:0 24px}

/* ---------- NAV ---------- */
.nav{position:fixed;top:0;left:0;right:0;z-index:50;transition:.3s;
  background:transparent;backdrop-filter:blur(0)}
.nav.scrolled{background:var(--nav-bg);backdrop-filter:blur(16px);border-bottom:1px solid var(--line);
  box-shadow:0 8px 30px rgba(0,0,0,.28)}
.nav-inner{max-width:var(--max);margin:0 auto;padding:16px 24px;display:flex;align-items:center;justify-content:space-between}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:.14em;font-size:18px}
.brand-logo{height:30px;width:auto;display:block;object-fit:contain;flex:0 0 auto}
.nav-links{display:flex;align-items:center;gap:28px}
.nav-links a{color:var(--muted);font-size:14px;font-weight:500;transition:.2s}
.nav-links a:hover{color:var(--ink)}
.lang-toggle{background:transparent;border:1px solid var(--line);color:var(--ink);
  padding:7px 14px;border-radius:99px;font-family:inherit;font-size:13px;cursor:pointer;transition:.2s}
.lang-toggle:hover{border-color:var(--brand);background:rgba(124,92,255,.12)}
.theme-toggle{display:inline-flex;align-items:center;justify-content:center;
  width:38px;height:38px;background:transparent;border:1px solid var(--line);
  color:var(--ink);border-radius:99px;cursor:pointer;padding:0;transition:.2s}
.theme-toggle:hover{border-color:var(--brand);background:rgba(124,92,255,.12)}
.theme-toggle svg{display:block}
/* show moon in dark mode (offer "switch to light"), sun in light mode */
.theme-toggle .icon-sun{display:none}
.theme-toggle .icon-moon{display:block}
html[data-theme="light"] .theme-toggle .icon-sun{display:block}
html[data-theme="light"] .theme-toggle .icon-moon{display:none}

/* ---------- HERO ---------- */
.hero{position:relative;min-height:auto;display:flex;align-items:center;justify-content:center;
  text-align:center;padding:178px 24px 64px;overflow:visible}
.hero-bg{position:absolute;inset:0;z-index:0;overflow:hidden;pointer-events:none}
.orb{position:absolute;border-radius:50%;filter:blur(80px);opacity:.55}
.orb-1{width:520px;height:520px;background:radial-gradient(circle,#7c5cff,transparent 70%);top:-120px;left:-80px;animation:float1 14s ease-in-out infinite}
.orb-2{width:480px;height:480px;background:radial-gradient(circle,#22d3ee,transparent 70%);bottom:-140px;right:-60px;animation:float2 17s ease-in-out infinite}
.grid-overlay{position:absolute;inset:0;
  background-image:linear-gradient(rgba(255,255,255,.04) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.04) 1px,transparent 1px);
  background-size:54px 54px;mask-image:radial-gradient(ellipse 70% 60% at 50% 40%,#000 30%,transparent 75%)}
.grid-overlay{background-image:linear-gradient(var(--grid-line) 1px,transparent 1px),linear-gradient(90deg,var(--grid-line) 1px,transparent 1px)}
@keyframes float1{50%{transform:translate(60px,40px)}}
@keyframes float2{50%{transform:translate(-50px,-30px)}}
.hero-content{position:relative;z-index:2;max-width:880px}
.hero-title{margin:0;font-weight:800;line-height:1.18;letter-spacing:-.02em}
.hero-word{display:block;font-size:clamp(56px,11vw,128px);line-height:1.16;padding:0.06em 0.04em 0.14em;
  background:linear-gradient(180deg,#fff 28%,#b9b3ff);-webkit-background-clip:text;background-clip:text;color:transparent;
  -webkit-text-fill-color:transparent}
/* Light mode: re-declaring the `background` shorthand resets background-clip
   back to border-box, which fills the whole word as a flat purple→cyan block
   with transparent (invisible) text. Re-assert the text-clip longhands so the
   gradient clips to the glyphs, not the box. */
html[data-theme="light"] .hero-word{
  background:linear-gradient(180deg,var(--brand) 10%,var(--brand-2));
  -webkit-background-clip:text;background-clip:text;
  color:transparent;-webkit-text-fill-color:transparent}
.hero-sub{display:block;font-size:clamp(20px,3.4vw,34px);font-weight:600;color:var(--muted);
  line-height:1.3;margin-top:8px;letter-spacing:.04em}
.hero-tagline{max-width:640px;margin:26px auto 0;color:var(--muted);font-size:clamp(16px,2.2vw,19px)}
.hero-cta{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;margin-top:38px}
.btn{position:relative;display:inline-flex;align-items:center;justify-content:center;padding:14px 30px;border-radius:99px;
  font-weight:600;font-size:15px;letter-spacing:.01em;cursor:pointer;border:1px solid transparent;
  transition:transform .25s cubic-bezier(.2,.7,.2,1),box-shadow .25s ease,background .25s ease,border-color .25s ease}
.btn-primary{background:linear-gradient(135deg,var(--brand),#9b7bff);color:#fff;
  box-shadow:0 10px 30px rgba(124,92,255,.38),inset 0 1px 0 rgba(255,255,255,.18)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 18px 44px rgba(124,92,255,.5),inset 0 1px 0 rgba(255,255,255,.22)}
.btn-primary:active{transform:translateY(0);box-shadow:0 8px 22px rgba(124,92,255,.42)}
.btn-ghost{border-color:var(--line);color:var(--ink);background:rgba(255,255,255,.03)}
.btn-ghost:hover{transform:translateY(-2px);border-color:rgba(34,211,238,.55);background:rgba(34,211,238,.09);box-shadow:0 12px 30px rgba(0,0,0,.3)}
.btn-ghost:active{transform:translateY(0)}
.btn:focus-visible{outline:2px solid var(--brand-2);outline-offset:3px}
.hero-scroll{display:none}
@keyframes scroll{0%{opacity:0;transform:translateY(-4px)}40%{opacity:1}80%,100%{opacity:0;transform:translateY(10px)}}

/* ---------- SECTIONS ---------- */
.section{padding:110px 0;position:relative}
.about{background:linear-gradient(180deg,var(--bg),var(--bg-2))}
.section-head{max-width:760px;margin:0 0 56px}
.kicker{display:inline-block;color:var(--brand-2);font-size:13px;font-weight:600;letter-spacing:.18em;text-transform:uppercase;margin-bottom:14px}
.section-head h2{font-size:clamp(28px,4.4vw,46px);line-height:1.12;margin:0;font-weight:800;letter-spacing:-.01em}
.section-lead{color:var(--muted);font-size:18px;margin-top:18px}

/* ABOUT */
.about-grid{display:grid;grid-template-columns:1.5fr 1fr;gap:54px;align-items:start}
.about-text p{color:var(--muted);font-size:17px;margin:0 0 20px}
.about-stats{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:1fr 1fr;gap:16px}
.about-stats li{background:linear-gradient(180deg,var(--panel),var(--panel-2));border:1px solid var(--line);
  border-radius:var(--radius);padding:24px 20px;
  transition:transform .35s cubic-bezier(.2,.7,.2,1),border-color .35s ease,box-shadow .35s ease}
.about-stats li:hover{transform:translateY(-5px);border-color:rgba(34,211,238,.45);box-shadow:0 16px 40px rgba(0,0,0,.4)}
.stat-big{display:block;font-size:34px;font-weight:800;
  background:linear-gradient(135deg,var(--brand-2),var(--brand));-webkit-background-clip:text;background-clip:text;color:transparent}
.stat-label{display:block;color:var(--muted);font-size:13.5px;margin-top:8px}

/* MILESTONES TIMELINE */
.milestones{background:linear-gradient(180deg,var(--bg-2),var(--bg))}
.timeline{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.tl-card{background:linear-gradient(180deg,var(--panel),var(--panel-2));border:1px solid var(--line);
  border-radius:var(--radius);overflow:hidden;display:flex;flex-direction:column;
  transition:transform .35s cubic-bezier(.2,.7,.2,1),border-color .35s ease,box-shadow .35s ease}
.tl-card:hover{transform:translateY(-6px);border-color:rgba(124,92,255,.5);box-shadow:0 22px 54px rgba(0,0,0,.5)}
.tl-card:focus-within{border-color:rgba(124,92,255,.5)}
.tl-thumb{position:relative;aspect-ratio:16/10;overflow:hidden;background:var(--img-bg);
  display:block;width:100%;border:0;padding:0;cursor:pointer;font:inherit;color:inherit}
.tl-thumb:focus-visible{outline:2px solid var(--brand-2);outline-offset:-2px}
.tl-thumb img{width:100%;height:100%;object-fit:cover;transition:transform .6s cubic-bezier(.2,.7,.2,1)}
.tl-card:hover .tl-thumb img{transform:scale(1.06)}
.tl-date{position:absolute;top:12px;left:12px;background:var(--chip-bg);backdrop-filter:blur(6px);
  color:var(--brand-2);font-size:12px;font-weight:600;padding:5px 11px;border-radius:99px;letter-spacing:.04em}
.tl-tag{position:absolute;top:12px;right:12px;background:rgba(124,92,255,.85);color:#fff;
  font-size:11px;font-weight:600;padding:5px 10px;border-radius:99px;text-transform:uppercase;letter-spacing:.06em}
.tl-body{padding:20px 20px 22px;display:flex;flex-direction:column;flex:1}
.tl-body h3{margin:0 0 10px;font-size:17.5px;line-height:1.3;font-weight:700}
.tl-body p{color:var(--muted);font-size:14px;margin:0 0 18px;flex:1}
.tl-link{display:inline-flex;align-items:center;gap:7px;color:var(--brand-2);font-size:13.5px;font-weight:600;align-self:flex-start;transition:.2s;
  background:none;border:0;padding:0;cursor:pointer;font-family:inherit}
.tl-link:hover{gap:11px;color:var(--link-hi)}
.tl-link svg{width:14px;height:14px}

/* CONTACT */
.contact{background:var(--bg);padding-bottom:0}
.contact-inner{max-width:980px}
.contact-head{max-width:620px;margin-bottom:40px}
.contact-head h2{font-size:clamp(30px,5vw,52px);margin:6px 0 14px;font-weight:800}
.contact-head p{color:var(--muted);font-size:17px;margin:0}
.contact-form{max-width:720px;margin-bottom:90px}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.form-field{margin-bottom:18px}
.form-field label{display:block;color:var(--brand-2);font-size:12px;letter-spacing:.16em;text-transform:uppercase;font-weight:600;margin-bottom:8px}
.form-field input,.form-field textarea{width:100%;box-sizing:border-box;background:var(--panel);border:1px solid var(--line);
  border-radius:12px;padding:14px 16px;color:var(--ink);font-family:var(--font);font-size:15.5px;
  transition:border-color .25s ease,box-shadow .25s ease,background .25s ease;resize:vertical}
.form-field input::placeholder,.form-field textarea::placeholder{color:rgba(163,167,196,.5)}
.form-field input:hover,.form-field textarea:hover{border-color:rgba(255,255,255,.16)}
.form-field input:focus,.form-field textarea:focus{outline:none;background:var(--panel-2);
  border-color:rgba(124,92,255,.65);box-shadow:0 0 0 3px rgba(124,92,255,.18)}
.form-submit{border:none;cursor:pointer;font-size:15.5px}
.form-success{margin:18px 0 0;padding:16px 18px;border-radius:12px;font-size:15.5px;font-weight:600;
  color:#7ef0c0;background:rgba(46,196,134,.12);border:1px solid rgba(46,196,134,.4)}

/* FOOTER */
.footer{border-top:1px solid var(--line);padding:30px 0;background:var(--bg-2)}
.footer-inner{display:flex;align-items:center;justify-content:space-between;gap:18px;flex-wrap:wrap}
.copyright{color:var(--muted);font-size:13px;margin:0}

/* reveal */
.reveal{opacity:0;transform:translateY(30px);transition:opacity .8s cubic-bezier(.2,.7,.2,1),transform .8s cubic-bezier(.2,.7,.2,1)}
.reveal.in{opacity:1;transform:none}
.tl-card.reveal{transition-delay:calc(var(--d,0) * 70ms)}

/* ---------- HERO BANNER CAROUSEL (full-width showcase) ---------- */
.banner-section{position:relative;padding:0 0 8px;background:var(--bg)}
.banner{position:relative;width:min(1320px,calc(100% - 48px));margin:0 auto;
  border-radius:24px;overflow:hidden;border:1px solid var(--line);background:#0c0e1a;
  box-shadow:0 34px 90px rgba(0,0,0,.6),0 0 0 1px rgba(124,92,255,.08)}
.banner-track{position:relative;height:clamp(360px,64vh,680px);width:100%}
.banner-slide{position:absolute;inset:0;margin:0;opacity:0;
  transition:opacity 1.1s ease;pointer-events:none}
.banner-slide.active{opacity:1;pointer-events:auto}
.banner-slide img{width:100%;height:100%;object-fit:cover;object-position:center 38%;
  transform:scale(1.06);transition:transform .6s ease}
.banner-slide.active img{animation:kenburns 9s ease-out forwards}
@keyframes kenburns{from{transform:scale(1.005)}to{transform:scale(1.085)}}
.banner-slide::after{content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(180deg,rgba(8,9,16,.22) 0%,transparent 26%,transparent 48%,rgba(8,9,16,.62) 78%,rgba(8,9,16,.94) 100%)}
.banner-caption{position:absolute;left:0;right:0;bottom:0;z-index:2;
  padding:clamp(24px,4vw,46px) clamp(26px,5vw,58px);text-align:left;color:#fff;
  font-size:clamp(18px,2.8vw,30px);font-weight:700;letter-spacing:.01em;
  line-height:1.25;text-shadow:0 2px 24px rgba(0,0,0,.55);max-width:760px}
.banner-arrow{position:absolute;top:50%;transform:translateY(-50%);z-index:3;
  width:52px;height:52px;border-radius:50%;border:1px solid rgba(255,255,255,.18);
  background:rgba(10,11,18,.45);backdrop-filter:blur(8px);color:#fff;
  font-size:28px;line-height:1;cursor:pointer;display:flex;align-items:center;
  justify-content:center;transition:.25s;opacity:0}
.banner:hover .banner-arrow{opacity:.9}
.banner-arrow:hover{background:rgba(124,92,255,.8);opacity:1;border-color:transparent;transform:translateY(-50%) scale(1.06)}
.banner-prev{left:22px}.banner-next{right:22px}
.banner-dots{position:absolute;bottom:22px;right:clamp(24px,5vw,46px);z-index:4;
  display:flex;gap:10px}
.banner-dot{width:10px;height:10px;border-radius:50%;border:0;cursor:pointer;
  background:rgba(255,255,255,.4);transition:.3s;padding:0}
.banner-dot:hover{background:rgba(255,255,255,.7)}
.banner-dot.active{background:var(--brand-2);width:30px;border-radius:99px;box-shadow:0 0 14px rgba(34,211,238,.6)}
/* Light-mode hardening: the banner shows real photos with a white caption over
   a dark bottom gradient in BOTH themes. Pin the image/slide visibility, the
   dark overlay and the white caption so no light-theme variable or
   gradient-text rule can blank them out. */
html[data-theme="light"] .banner-slide,
html[data-theme="light"] .banner-slide img{visibility:visible;filter:none}
html[data-theme="light"] .banner-slide img{opacity:1}
html[data-theme="light"] .banner-slide::after{
  background:linear-gradient(180deg,rgba(8,9,16,.22) 0%,transparent 26%,transparent 48%,rgba(8,9,16,.62) 78%,rgba(8,9,16,.94) 100%)}
html[data-theme="light"] .banner-caption{
  color:#fff;-webkit-text-fill-color:#fff;opacity:1;visibility:visible;
  text-shadow:0 2px 24px rgba(0,0,0,.6)}

/* ---------- INTERNAL EVENT MODAL ---------- */
.event-modal{position:fixed;inset:0;z-index:100;display:none}
.event-modal.open{display:block}
.em-backdrop{position:absolute;inset:0;background:rgba(5,6,12,.82);
  backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);
  animation:emFade .3s ease both}
@keyframes emFade{from{opacity:0}to{opacity:1}}
.em-dialog{position:relative;z-index:2;
  width:min(1100px,92vw);max-width:1100px;
  max-height:90vh;display:flex;flex-direction:column;overflow:hidden;
  margin:5vh auto 0;background:var(--panel);
  border:1px solid var(--line);border-radius:26px;
  box-shadow:0 50px 120px rgba(0,0,0,.66),0 0 0 1px rgba(124,92,255,.08);
  animation:emIn .4s cubic-bezier(.2,.7,.2,1)}
@keyframes emIn{from{opacity:0;transform:translateY(26px) scale(.985)}to{opacity:1;transform:none}}
/* slim header bar — date + category + close only, NO large cover image */
.em-bar{position:relative;flex:0 0 auto;display:flex;align-items:center;gap:12px;
  padding:14px clamp(18px,4vw,26px);border-bottom:1px solid var(--line);
  background:var(--panel-2)}
.em-close{flex:0 0 auto;margin-left:auto;width:38px;height:38px;
  border-radius:50%;border:1px solid var(--line);
  background:var(--em-close-bg);
  color:var(--ink);font-size:24px;line-height:1;cursor:pointer;
  display:flex;align-items:center;justify-content:center;
  transition:background .2s,transform .2s,border-color .2s}
.em-close:hover{background:rgba(124,92,255,.85);border-color:transparent;color:#fff;transform:rotate(90deg)}
.em-date{flex:0 0 auto;background:var(--em-chip-bg);
  color:var(--brand-2);font-size:12.5px;font-weight:600;padding:6px 13px;border-radius:99px}
.em-tag{flex:0 0 auto;background:rgba(124,92,255,.9);
  color:#fff;font-size:11px;font-weight:600;padding:6px 12px;border-radius:99px;
  text-transform:uppercase;letter-spacing:.06em}
/* scrollable body */
.em-content{flex:1 1 auto;overflow-y:auto;overscroll-behavior:contain;
  scroll-behavior:smooth;scrollbar-width:thin;
  padding:34px clamp(22px,5vw,56px) 48px}
.em-content::-webkit-scrollbar{width:10px}
.em-content::-webkit-scrollbar-thumb{background:rgba(124,92,255,.4);border-radius:99px;
  border:3px solid var(--panel)}
.em-title{margin:0 auto 22px;max-width:760px;font-size:clamp(22px,2.4vw,30px);font-weight:800;
  line-height:1.3;padding-bottom:18px;border-bottom:1px solid var(--line)}
.em-body{margin:0 auto;color:var(--em-body-ink);font-size:17px;line-height:1.85}
/* keep prose at a comfortable reading width, let galleries breathe wider */
.em-body .em-para{margin:0 auto 20px;max-width:760px}
.em-body .em-para:last-child{margin-bottom:0}
.em-figure{margin:28px auto 30px;max-width:900px;border-radius:16px;overflow:hidden;
  background:var(--img-bg);border:1px solid var(--line)}
.em-figure img{display:block;width:100%;height:auto}
.em-gallery{display:grid;grid-template-columns:repeat(2,1fr);gap:14px;margin:28px 0 32px}
.em-gallery-dense{grid-template-columns:repeat(3,1fr)}
.em-gallery img{display:block;width:100%;height:100%;aspect-ratio:4/3;object-fit:cover;
  border-radius:14px;border:1px solid var(--line);background:var(--img-bg);
  transition:transform .35s cubic-bezier(.2,.7,.2,1),box-shadow .35s}
.em-gallery img:hover{transform:scale(1.025);box-shadow:0 16px 40px rgba(0,0,0,.45)}
/* a lone trailing image in a 2-col grid spans full width */
.em-gallery:not(.em-gallery-dense) img:nth-child(odd):last-child{grid-column:1/-1;aspect-ratio:16/9}

/* ---------- RESPONSIVE ---------- */
@media(max-width:980px){
  .about-grid{grid-template-columns:1fr;gap:36px}
  .timeline{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:980px){
  .banner-track{height:clamp(320px,52vh,520px)}
}
@media(max-width:680px){
  .nav-links a:not(.lang-toggle){display:none}
  .section{padding:72px 0}
  .hero{padding:128px 20px 40px}
  .timeline{grid-template-columns:1fr}
  .form-row{grid-template-columns:1fr}
  .about-stats{grid-template-columns:1fr 1fr}
  .footer-inner{flex-direction:column;text-align:center}
  .banner{width:calc(100% - 28px);border-radius:18px}
  .banner-track{height:62vh;min-height:340px;max-height:560px}
  .banner-arrow{width:42px;height:42px;font-size:22px;opacity:.85}
  .banner-prev{left:12px}.banner-next{right:12px}
  .banner-caption{padding:22px 22px 30px;font-size:clamp(16px,5vw,22px)}
  .banner-dots{bottom:16px;right:18px}
  /* event modal — full width with comfortable padding on phones */
  .em-dialog{width:calc(100% - 24px);max-height:92vh;margin:4vh auto 0;border-radius:20px}
  .em-content{padding:26px 20px 36px}
  .em-gallery,.em-gallery-dense{grid-template-columns:repeat(2,1fr);gap:10px}
}
@media(max-width:420px){
  .em-gallery,.em-gallery-dense{grid-template-columns:1fr}
}
@media(prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
  .reveal{opacity:1;transform:none}
}