/* ============================================================
   NorthStar AI Research Institute
   Shared design system — deep-blue / glassmorphism / cyan
   ============================================================ */

:root{
  /* Palette */
  --bg:        #04060e;
  --bg-1:      #05080f;
  --bg-2:      #070c1c;
  --bg-grad-a: #070d18;
  --bg-grad-b: #04060c;

  --surface:      rgba(255,255,255,.045);
  --surface-2:    rgba(255,255,255,.07);
  --surface-hi:   rgba(255,255,255,.12);
  --border:       rgba(150,190,255,.14);
  --border-hi:    rgba(120,200,255,.42);

  --text:    #e9f1ff;
  --text-2:  #b9c8e6;
  --muted:   #7e90b4;
  --faint:   #4c5b78;

  --accent:   #35c8ff;   /* cyan */
  --accent-2: #4f7cff;   /* electric blue */
  --accent-3: #7c5cff;   /* violet (sparing) */
  --accent-soft: rgba(53,200,255,.14);

  --glow:    0 0 0 1px rgba(53,200,255,.25), 0 0 38px -8px rgba(53,200,255,.55);
  --glow-soft: 0 18px 60px -20px rgba(20,80,180,.55);

  --radius:    16px;
  --radius-lg: 24px;
  --radius-sm: 10px;

  --maxw: 1240px;
  --nav-h: 80px;

  --font-display: "Sora", system-ui, sans-serif;
  --font-ui:      "Manrope", "Noto Sans SC", system-ui, sans-serif;
  --font-cjk:     "Noto Sans SC", "Manrope", system-ui, sans-serif;
  --font-mono:    "IBM Plex Mono", ui-monospace, monospace;

  --ease: cubic-bezier(.22,.61,.36,1);
  --ease-out: cubic-bezier(.16,.84,.44,1);
  --ease-soft: cubic-bezier(.33,.9,.27,1);
}

*{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }

body{
  margin:0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
  cursor:none;
}
@media (pointer:coarse){ body{ cursor:auto; } }

/* Fixed background — calm technical lab field (no cosmic nebula) */
#starfield{
  position:fixed; inset:0; z-index:0;
  pointer-events:none;
  background:
    radial-gradient(1000px 520px at 50% -14%, rgba(40,92,168,.13), transparent 60%),
    linear-gradient(180deg, var(--bg-grad-a), var(--bg-grad-b) 56%);
}
#starfield::after{ /* edge vignette to ground the page */
  content:""; position:absolute; inset:0;
  background:radial-gradient(130% 100% at 50% 38%, transparent 62%, rgba(2,4,9,.72));
}
/* technical blueprint grid — the dominant ambient texture now */
.bpgrid{
  position:fixed; inset:0; z-index:1; pointer-events:none; opacity:.9;
  background-image:
    linear-gradient(rgba(96,150,220,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(96,150,220,.05) 1px, transparent 1px),
    linear-gradient(rgba(96,150,220,.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(96,150,220,.025) 1px, transparent 1px);
  background-size:120px 120px, 120px 120px, 24px 24px, 24px 24px;
  mask-image:radial-gradient(150% 130% at 50% 0%, #000 30%, transparent 80%);
  -webkit-mask-image:radial-gradient(150% 130% at 50% 0%, #000 30%, transparent 80%);
}
.grain{
  position:fixed; inset:0; z-index:1; pointer-events:none; opacity:.25;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.03'/%3E%3C/svg%3E");
  mix-blend-mode:overlay;
}

main, .page{ position:relative; z-index:2; }

::selection{ background:rgba(53,200,255,.3); color:#fff; }

/* ---------- Typography ---------- */
h1,h2,h3,h4{ font-family:var(--font-display); font-weight:700; line-height:1.05; letter-spacing:-.02em; margin:0; }
.display{ font-size:clamp(40px, 7vw, 92px); }
.h1{ font-size:clamp(34px,5vw,64px); }
.h2{ font-size:clamp(28px,3.6vw,46px); }
.h3{ font-size:clamp(20px,2vw,28px); }
p{ margin:0; }

.eyebrow{
  font-family:var(--font-mono);
  font-size:12.5px; letter-spacing:.32em; text-transform:uppercase;
  color:var(--accent); display:inline-flex; align-items:center; gap:10px;
}
.eyebrow::before{ content:""; width:26px; height:1px; background:linear-gradient(90deg,var(--accent),transparent); }

.lead{ color:var(--text-2); font-size:clamp(16px,1.5vw,20px); line-height:1.7; }
.muted{ color:var(--muted); }
.mono{ font-family:var(--font-mono); }
.grad-text{
  background:linear-gradient(100deg,#fff 10%, var(--accent) 55%, var(--accent-3) 100%);
  -webkit-background-clip:text; background-clip:text; color:transparent;
}

/* ---------- Layout ---------- */
.wrap{ max-width:var(--maxw); margin:0 auto; padding:0 28px; }
.section{ padding:clamp(72px,11vh,150px) 0; position:relative; }
.center{ text-align:center; }
.stack{ display:flex; flex-direction:column; }

/* ---------- Nav ---------- */
.nav{
  position:fixed; top:0; left:0; right:0; height:var(--nav-h); z-index:60;
  display:flex; align-items:center;
  backdrop-filter:blur(20px) saturate(140%);
  -webkit-backdrop-filter:blur(20px) saturate(140%);
  background:rgba(7,11,24,.62);
  border-bottom:1px solid var(--border);
  transition:background .4s, border-color .4s;
}
.nav.scrolled{ background:rgba(5,8,16,.82); }
.nav .wrap{ display:flex; align-items:center; justify-content:space-between; width:100%; }
.brand{ display:flex; align-items:center; gap:13px; text-decoration:none; color:var(--text); }
.brand .mark{ width:34px; height:34px; flex:none; }
.brand .bt{ display:flex; flex-direction:column; line-height:1.05; }
.brand .bt b{ font-family:var(--font-display); font-size:15px; letter-spacing:.01em; }
.brand .bt span{ font-family:var(--font-mono); font-size:9.5px; letter-spacing:.26em; color:var(--muted); text-transform:uppercase; }

.navlinks{ display:flex; align-items:center; gap:4px; }
.navlinks a{
  position:relative; color:var(--text-2); text-decoration:none;
  font-size:14px; font-weight:500; padding:9px 14px; border-radius:9px;
  transition:color .25s, transform .25s;
}
.navlinks a .en{ display:block; font-size:9px; font-family:var(--font-mono); letter-spacing:.18em; color:var(--faint); text-transform:uppercase; margin-top:1px; }
.navlinks a:hover{ color:var(--accent); transform:translateY(-1px); }
.navlinks a::after{
  content:""; position:absolute; left:14px; right:14px; bottom:3px; height:1.5px;
  background:linear-gradient(90deg,transparent,var(--accent),transparent);
  transform:scaleX(0); transform-origin:center; transition:transform .3s var(--ease);
  box-shadow:0 0 10px var(--accent);
}
.navlinks a:hover::after{ transform:scaleX(1); }
.navlinks a.active{ color:#fff; }
.navlinks a.active::after{ transform:scaleX(1); animation:flow 2.4s linear infinite; }
@keyframes flow{ 0%{background-position:0 0} 100%{background-position:40px 0} }

.nav-cta{ display:flex; align-items:center; gap:10px; }
.lang-switch{
  display:inline-flex; align-items:center; gap:4px; padding:5px;
  border:1px solid var(--border); border-radius:999px; background:var(--surface);
  backdrop-filter:blur(10px);
}
.lang-switch button{
  min-height:32px; padding:0 12px; border:0; border-radius:999px; background:transparent;
  color:var(--muted); font-family:var(--font-mono); font-size:11px; letter-spacing:.08em;
  cursor:none; transition:background .2s, color .2s, box-shadow .2s;
}
.lang-switch button.on{
  color:#02121f; background:linear-gradient(100deg,var(--accent),#8ad7ff);
  box-shadow:0 0 18px -6px rgba(53,200,255,.9);
}
.lang-switch button:not(.on):hover{ color:#fff; background:rgba(255,255,255,.06); }
@media(pointer:coarse){ .lang-switch button{ cursor:pointer; } }

/* ---------- Buttons ---------- */
.btn{
  position:relative; display:inline-flex; align-items:center; gap:9px;
  font-family:var(--font-ui); font-weight:600; font-size:14.5px;
  padding:13px 24px; border-radius:999px; border:1px solid transparent;
  text-decoration:none; cursor:none; overflow:hidden;
  transition:transform .2s var(--ease), box-shadow .3s, background .3s, border-color .3s;
}
@media(pointer:coarse){ .btn{ cursor:pointer; } }
.btn svg{ width:16px; height:16px; }
.btn-primary{
  color:#02121f; font-weight:700;
  background:linear-gradient(100deg,var(--accent),#8ad7ff);
  box-shadow:0 0 0 1px rgba(53,200,255,.4), 0 14px 38px -12px rgba(53,200,255,.7);
}
.btn-primary:hover{ transform:translateY(-2px); box-shadow:0 0 0 1px rgba(53,200,255,.7), 0 18px 50px -10px rgba(53,200,255,.9); }
.btn-primary:active{ transform:translateY(1px) scale(.98); }
.btn-ghost{
  color:var(--text); background:var(--surface); border-color:var(--border);
  backdrop-filter:blur(10px);
}
.btn-ghost:hover{ border-color:var(--border-hi); color:#fff; transform:translateY(-2px); box-shadow:var(--glow); }
.btn-ghost:active{ transform:translateY(1px) scale(.98); }
.btn-sm{ padding:9px 16px; font-size:13px; }

/* ripple */
.ripple{ position:absolute; border-radius:50%; transform:translate(-50%,-50%) scale(0); background:radial-gradient(circle, rgba(255,255,255,.7), transparent 70%); pointer-events:none; animation:ripple .7s ease-out forwards; mix-blend-mode:screen; }
@keyframes ripple{ to{ transform:translate(-50%,-50%) scale(18); opacity:0; } }

/* wallet chip */
.wallet{ font-family:var(--font-mono); font-size:12.5px; letter-spacing:.04em; }
.wallet .dot{ width:7px; height:7px; border-radius:50%; background:#2de2b6; box-shadow:0 0 8px #2de2b6; display:inline-block; }

/* ---------- Glass card ---------- */
.glass{
  background:linear-gradient(160deg, var(--surface-2), var(--surface));
  border:1px solid var(--border);
  border-radius:var(--radius-lg);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
}
.card{
  position:relative; padding:30px; border-radius:var(--radius-lg);
  background:linear-gradient(160deg, var(--surface-2), var(--surface));
  border:1px solid var(--border);
  backdrop-filter:blur(12px); overflow:hidden;
  transform-style:preserve-3d;
  transition:transform .25s var(--ease-out), border-color .4s, box-shadow .4s;
}
.card::before{
  content:""; position:absolute; inset:0; border-radius:inherit; padding:1px;
  background:linear-gradient(140deg, rgba(53,200,255,.5), transparent 40%);
  -webkit-mask:linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite:xor; mask-composite:exclude; opacity:0; transition:opacity .4s; z-index:2;
}
/* cursor spotlight */
.card::after{
  content:""; position:absolute; inset:0; border-radius:inherit; pointer-events:none; opacity:0; transition:opacity .35s; z-index:1;
  background:radial-gradient(280px circle at var(--mx,50%) var(--my,50%), rgba(80,180,255,.14), transparent 62%);
}
.card:hover{ transform:translateY(-8px); border-color:var(--border-hi); box-shadow:var(--glow-soft), var(--glow); }
.card:hover::before{ opacity:1; }
.card:hover::after{ opacity:1; }
.card:active{ transform:translateY(-3px) scale(.992); }

/* ---------- Reveal on scroll (calm focus-in) ---------- */
.reveal{ opacity:0; transform:translateY(9px); filter:blur(5px); will-change:opacity,transform,filter;
  transition:opacity 1.25s var(--ease-out), transform 1.25s var(--ease-out), filter 1.1s var(--ease-out); }
.reveal.in{ opacity:1; transform:none; filter:none; }
.reveal[data-d="1"]{ transition-delay:.07s } .reveal[data-d="2"]{ transition-delay:.14s }
.reveal[data-d="3"]{ transition-delay:.21s } .reveal[data-d="4"]{ transition-delay:.28s }
.reveal[data-d="5"]{ transition-delay:.35s } .reveal[data-d="6"]{ transition-delay:.42s }
@media (prefers-reduced-motion:reduce){ .reveal{ opacity:1; transform:none; filter:none; transition:none; } }

/* ---------- Scroll progress ---------- */
#scrollbar{ position:fixed; top:0; left:0; height:2px; width:0; z-index:80;
  background:linear-gradient(90deg, var(--accent), var(--accent-3));
  box-shadow:0 0 12px rgba(53,200,255,.8); transition:width .12s linear; }

/* ---------- Custom cursor ---------- */
#cursor, #cursor-dot{ position:fixed; top:0; left:0; z-index:9999; pointer-events:none; mix-blend-mode:screen; }
#cursor{ width:34px; height:34px; margin:-17px 0 0 -17px; border:1.5px solid rgba(53,200,255,.6); border-radius:50%; transition:width .25s, height .25s, margin .25s, border-color .25s, background .25s; }
#cursor.hot{ width:54px; height:54px; margin:-27px 0 0 -27px; border-color:var(--accent); background:rgba(53,200,255,.08); }
#cursor-dot{ width:5px; height:5px; margin:-2.5px 0 0 -2.5px; border-radius:50%; background:var(--accent); box-shadow:0 0 10px var(--accent); }
@media (pointer:coarse){ #cursor,#cursor-dot{ display:none; } }

/* ---------- Page transition ---------- */
#pageveil{
  position:fixed; inset:0; z-index:9000; pointer-events:none;
  background:var(--bg);
  opacity:0; transition:opacity .6s var(--ease-soft);
}
#pageveil.show{ opacity:1; pointer-events:all; }
/* leaving: gently dissolve current content */
body.leaving main{ opacity:0; transform:translateY(-10px); filter:blur(4px);
  transition:opacity .5s var(--ease-soft), transform .5s var(--ease-soft), filter .5s var(--ease-soft); }
/* entering: soft focus-in */
body.entering main{ animation:pageIn 1s var(--ease-out) both; }
@keyframes pageIn{ from{ opacity:0; transform:translateY(16px); filter:blur(8px); } to{ opacity:1; transform:none; filter:none; } }

/* ---------- Footer ---------- */
.footer{ position:relative; z-index:2; border-top:1px solid var(--border); margin-top:40px; padding:62px 0 40px; }
.footer .grid{ display:grid; grid-template-columns:1.6fr 1fr 1fr 1fr; gap:40px; }
.footer h5{ font-family:var(--font-mono); font-size:11px; letter-spacing:.2em; text-transform:uppercase; color:var(--muted); margin:0 0 16px; }
.footer a{ display:block; color:var(--text-2); text-decoration:none; font-size:14px; padding:5px 0; transition:color .2s; }
.footer a:hover{ color:var(--accent); }
.footer .bottom{ display:flex; justify-content:space-between; align-items:center; margin-top:48px; padding-top:24px; border-top:1px solid var(--border); color:var(--faint); font-size:13px; font-family:var(--font-mono); }

/* ---------- Helpers ---------- */
.tag{ display:inline-flex; align-items:center; gap:7px; padding:6px 13px; border-radius:999px; background:var(--surface); border:1px solid var(--border); font-family:var(--font-mono); font-size:11.5px; letter-spacing:.12em; text-transform:uppercase; color:var(--text-2); }
.divider{ height:1px; background:linear-gradient(90deg,transparent,var(--border),transparent); }
.grid-2{ display:grid; grid-template-columns:repeat(2,1fr); gap:24px; }
.grid-3{ display:grid; grid-template-columns:repeat(3,1fr); gap:24px; }
.grid-4{ display:grid; grid-template-columns:repeat(4,1fr); gap:20px; }
.kicker-num{ font-family:var(--font-mono); color:var(--accent); font-size:13px; }

@media (max-width:1000px){
  .footer .grid{ grid-template-columns:1fr 1fr; }
  .grid-4{ grid-template-columns:repeat(2,1fr); }
  .grid-3{ grid-template-columns:1fr; }
  .navlinks{ display:none; }
}
@media (max-width:680px){
  .grid-2,.grid-4{ grid-template-columns:1fr; }
  .nav-cta .joinbtn{ display:none; }
}

/* page-specific helpers used across pages */
.section-head{ max-width:720px; margin:0 auto 56px; text-align:center; }
.section-head .h2{ margin:16px 0 14px; }
.glow-orb{ position:absolute; border-radius:50%; filter:blur(90px); opacity:.18; pointer-events:none; z-index:0; }