/* ============================================================
   Nightt — 夜 / night-sky personal site
   A bespoke design language. Deep night, moonlight serifs,
   constellations. Nothing borrowed from any other system.
   ============================================================ */

:root{
  --night-0:#04060f;  --night-1:#080b1d;  --night-2:#101637;  --night-3:#1b2550;
  --moon:#eef3ff;
  --ink:#eaf0ff;      --dim:#aebbe6;      --faint:#7e8bbf;    --hair:rgba(143,180,255,.16);
  --glow:#8fb4ff;     --violet:#b79bff;   --gold:#f0d28a;
  --serif:'Cormorant Garamond','Noto Serif SC',serif;
  --body:'Newsreader','Noto Serif SC',serif;
  --sans:'Space Grotesk','Noto Sans SC',sans-serif;
  --mono:'JetBrains Mono',monospace;
  --hand:'Ma Shan Zheng',cursive;
  --script:'Caveat',cursive;
  --ease:cubic-bezier(.16,1,.3,1);
  --maxw:1180px;
}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0; color:var(--ink); font-family:var(--body);
  background:var(--night-0);
  -webkit-font-smoothing:antialiased; text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
::selection{background:rgba(143,180,255,.28);color:#fff;}
a{color:inherit;text-decoration:none;}

/* ---------- fixed cosmos backdrop ---------- */
#cosmos{position:fixed;inset:0;z-index:-2;pointer-events:none;
  background:
    radial-gradient(120% 90% at 78% -10%,rgba(183,155,255,.10),transparent 50%),
    radial-gradient(130% 110% at 22% 4%,#1b2550 0%,#101637 34%,#080b1d 66%,#04060f 100%);}
#stars,#stars-near{position:fixed;inset:0;z-index:-2;pointer-events:none;}
.star{position:absolute;border-radius:50%;background:#fff;animation:tw var(--d,3.4s) ease-in-out infinite;}
@keyframes tw{0%,100%{opacity:.2}50%{opacity:.95}}
#stars.far .star{filter:blur(.3px);}
.moon{position:fixed;top:7vh;right:8vw;width:84px;height:84px;border-radius:50%;z-index:-2;pointer-events:none;
  background:radial-gradient(circle at 38% 36%,#fff,#dfe7ff 58%,#aab8e8 100%);
  box-shadow:0 0 70px 14px rgba(180,200,255,.28),inset -14px -9px 24px rgba(60,80,150,.5);}
.moon::after{content:'';position:absolute;top:-7px;right:-7px;width:66px;height:66px;border-radius:50%;
  background:radial-gradient(130% 110% at 22% 4%,#141a3c,#0a0f26 62%);}
.shoot{position:fixed;width:170px;height:2px;border-radius:2px;z-index:-1;top:16%;left:-180px;
  background:linear-gradient(90deg,transparent,rgba(255,255,255,.92));transform:rotate(17deg);opacity:0;
  animation:shoot 14s ease-in 6s infinite;}
@keyframes shoot{0%{left:-180px;top:12%;opacity:0}2.5%{opacity:1}11%{left:72%;top:38%;opacity:0}100%{opacity:0}}

/* ---------- nav ---------- */
.nav{position:fixed;top:0;left:0;right:0;z-index:50;display:flex;align-items:center;justify-content:space-between;
  padding:20px clamp(20px,5vw,56px);transition:background .3s,backdrop-filter .3s,border-color .3s;
  border-bottom:1px solid transparent;}
.nav.scrolled{background:rgba(8,11,29,.62);backdrop-filter:blur(14px);border-bottom-color:var(--hair);}
.nav .brand{font-family:var(--serif);font-size:24px;font-weight:500;letter-spacing:.02em;color:var(--moon);}
.nav .brand b{color:var(--violet);font-weight:500;}
.nav .brand i.num{font-style:normal;color:var(--moon);}
.nav-links{display:flex;gap:clamp(12px,2vw,30px);font-family:var(--sans);font-size:12.5px;letter-spacing:.03em;}
.nav-links a{color:var(--faint);transition:color .18s;position:relative;padding:4px 0;}
.nav-links a .en{display:block;font-size:9px;letter-spacing:.14em;text-transform:uppercase;opacity:.6;margin-top:1px;}
.nav-links a:hover,.nav-links a.active{color:var(--ink);}
.nav-links a.active::after{content:'';position:absolute;left:0;right:0;bottom:-2px;height:1px;background:var(--glow);
  box-shadow:0 0 8px var(--glow);}
.nav-toggle{display:none;}

/* ---------- shared section scaffold ---------- */
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 clamp(20px,5vw,56px);}
section{position:relative;padding:clamp(80px,12vh,150px) 0;}
.sec-head{display:flex;align-items:baseline;gap:18px;margin-bottom:48px;}
.sec-num{font-family:var(--mono);font-size:13px;color:var(--violet);letter-spacing:.1em;}
.sec-title{font-family:var(--serif);font-size:clamp(34px,5vw,52px);font-weight:500;line-height:1;color:var(--moon);}
.sec-title .en{font-family:var(--sans);font-size:12px;letter-spacing:.34em;text-transform:uppercase;
  color:var(--faint);font-weight:500;margin-left:14px;vertical-align:middle;}
.sec-head::after{content:'';flex:1;height:1px;background:linear-gradient(90deg,var(--hair),transparent);
  align-self:center;margin-top:6px;}

/* reveal-on-scroll: TRANSFORM ONLY (never opacity) so content can never
   stay invisible if a transition is paused/throttled (hidden tabs don't
   paint opacity transitions). IntersectionObserver toggles .in. */
.js .reveal{transform:translateY(26px);transition:transform .7s var(--ease);}
.js .reveal.in{transform:none;}

/* ============================================================
   HERO
   ============================================================ */
.hero{min-height:100vh;display:flex;flex-direction:column;justify-content:center;
  padding-top:40px;padding-bottom:64px;position:relative;}
.hero-kick{font-family:var(--sans);letter-spacing:.42em;font-size:11.5px;text-transform:uppercase;
  color:var(--glow);opacity:.9;margin-bottom:18px;}
.hero-name{font-family:var(--serif);font-weight:500;font-size:clamp(58px,12.5vw,156px);line-height:.82;margin:0;
  letter-spacing:.005em;color:var(--moon);text-shadow:0 0 42px rgba(143,180,255,.5),0 0 100px rgba(143,180,255,.22);}
.hero-name .tt{color:var(--violet);text-shadow:0 0 42px rgba(183,155,255,.6),0 0 100px rgba(183,155,255,.32);}
.hero-name .num{color:var(--moon);}
.hero-id{font-family:var(--sans);font-size:14px;letter-spacing:.06em;color:var(--dim);margin-top:24px;}
.hero-id .cn{font-family:var(--body);}
.hero-tag{font-family:var(--serif);font-size:clamp(26px,4.2vw,44px);font-weight:500;line-height:1.18;
  margin:30px 0 0;color:#dce5ff;max-width:18em;}
.hero-tag .en{display:block;font-family:var(--body);font-style:italic;font-size:clamp(15px,1.6vw,19px);
  color:var(--faint);margin-top:12px;letter-spacing:.01em;}

/* education path in hero — the thing the eye should catch first */
.path{display:inline-flex;align-items:center;gap:18px;margin-top:42px;padding:16px 26px;
  border:1px solid var(--hair);border-radius:999px;background:rgba(16,22,55,.4);backdrop-filter:blur(6px);
  flex-wrap:wrap;}
.path .lab{font-family:var(--sans);font-size:9.5px;letter-spacing:.26em;text-transform:uppercase;color:var(--faint);
  margin-right:2px;}
.path .school{display:flex;flex-direction:column;line-height:1.15;}
.path .school .cn{font-family:var(--serif);font-size:22px;color:var(--moon);font-weight:500;}
.path .school .en{font-family:var(--sans);font-size:10px;letter-spacing:.08em;color:var(--faint);text-transform:uppercase;margin-top:2px;}
.path .arrow{position:relative;width:48px;height:14px;flex:0 0 auto;}
.path .arrow svg{width:100%;height:100%;overflow:visible;}
.path .arrow .ln{stroke:var(--glow);stroke-width:1.4;filter:drop-shadow(0 0 4px var(--glow));}

.scroll-hint{position:absolute;bottom:30px;left:50%;transform:translateX(-50%);
  font-family:var(--sans);font-size:11px;letter-spacing:.34em;text-transform:uppercase;color:#8a97cc;
  display:flex;align-items:center;gap:10px;}
.scroll-hint .ar{width:1px;height:28px;background:linear-gradient(#8a97cc,transparent);
  animation:fall 1.8s ease-in-out infinite;}
@keyframes fall{0%,100%{opacity:.3;transform:translateY(-4px)}50%{opacity:1;transform:translateY(2px)}}

/* hand-drawn guide — anchored INSIDE the target constellation so the arrow
   always points exactly at its stars, regardless of viewport. */
.hcon-guide{position:absolute;left:138px;top:122px;transform:translateX(-50%) rotate(-3deg);
  display:flex;flex-direction:column;align-items:center;gap:2px;pointer-events:none;
  white-space:nowrap;transition:opacity .3s;}
.hcon:hover .hcon-guide{opacity:0;}
.sh-note{text-align:center;line-height:1;}
.sh-note b{font-family:var(--hand);font-weight:400;font-size:24px;color:var(--glow);
  text-shadow:0 0 18px rgba(143,180,255,.5);letter-spacing:.04em;display:block;}
.sh-note i{font-family:var(--script);font-style:normal;font-size:15px;color:var(--faint);margin-top:4px;display:block;}
.sh-arrow{width:50px;height:74px;flex:0 0 auto;}
.sh-arrow path{stroke:var(--glow);filter:drop-shadow(0 0 5px rgba(143,180,255,.5));}
@media (max-width:760px){.hcon-guide{display:none;}}

/* hero constellations */
#hero-cons{position:absolute;inset:0;z-index:3;pointer-events:none;}
.hcon{position:absolute;transform:translate(-50%,-50%);pointer-events:auto;cursor:pointer;width:200px;text-align:center;}
.hcon svg{overflow:visible;display:block;margin:0 auto;}
.hcon .cl{stroke:rgba(170,190,255,.26);stroke-width:1;transition:stroke .3s;}
.hcon .cs{fill:#dfe8ff;opacity:.55;transition:opacity .3s;}
.hcon .cs.hub{fill:#fff;}
.hcon .lab{margin-top:7px;opacity:0;transition:opacity .3s,transform .3s;transform:translateY(4px);}
.hcon .lab .nm{font-family:var(--body);font-size:17px;color:#eef3ff;}
.hcon .lab .tg{font-family:var(--sans);font-size:9.5px;letter-spacing:.16em;text-transform:uppercase;color:var(--violet);margin-top:4px;}
.hcon:hover .nm-dot{opacity:1;}
.hcon:hover .cl{stroke:rgba(190,205,255,.85);}
.hcon:hover .cs{opacity:1;filter:drop-shadow(0 0 5px rgba(190,205,255,.9));}
.hcon:hover .lab{opacity:1;transform:none;}

/* ============================================================
   ABOUT
   ============================================================ */
.about-grid{display:grid;grid-template-columns:1.6fr 1fr;gap:clamp(36px,6vw,90px);align-items:start;}
.about-lede{font-family:var(--body);font-size:clamp(19px,2.1vw,24px);line-height:1.62;color:#dbe3ff;}
.about-lede em{font-style:italic;color:var(--moon);}
.facts{display:flex;flex-direction:column;gap:22px;border-left:1px solid var(--hair);padding-left:30px;}
.fact .k{font-family:var(--sans);font-size:10px;letter-spacing:.2em;text-transform:uppercase;color:var(--faint);}
.fact .v{font-family:var(--serif);font-size:21px;color:var(--moon);margin-top:5px;line-height:1.2;}
.fact .v small{display:block;font-family:var(--sans);font-size:11px;letter-spacing:.04em;color:var(--dim);margin-top:3px;text-transform:none;}

/* ============================================================
   EDUCATION — constellation timeline
   ============================================================ */
.edu{position:relative;margin-left:8px;}
.edu::before{content:'';position:absolute;left:7px;top:8px;bottom:8px;width:1px;
  background:linear-gradient(var(--glow),var(--violet));opacity:.45;}
.edu-node{position:relative;padding:0 0 46px 44px;}
.edu-node:last-child{padding-bottom:0;}
.edu-node .dot{position:absolute;left:0;top:5px;width:15px;height:15px;border-radius:50%;background:var(--night-1);
  border:2px solid var(--glow);box-shadow:0 0 14px var(--glow);}
.edu-node.cur .dot{border-color:var(--violet);box-shadow:0 0 16px var(--violet);}
.edu-node .when{font-family:var(--mono);font-size:12px;color:var(--violet);letter-spacing:.04em;}
.edu-node .school{font-family:var(--serif);font-size:clamp(26px,3.4vw,38px);color:var(--moon);font-weight:500;line-height:1.05;margin:6px 0 2px;}
.edu-node .school .en{font-family:var(--sans);font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--faint);margin-left:0;display:block;margin-top:4px;}
.edu-node .deg{font-family:var(--body);font-size:17px;color:var(--dim);margin-top:10px;}
.edu-node .deg .ph{color:var(--faint);font-style:italic;}

/* ============================================================
   EXPERIENCE
   ============================================================ */
.exp-item{display:grid;grid-template-columns:160px 1fr;gap:30px;padding:26px 0;border-top:1px solid var(--hair);}
.exp-item:last-child{border-bottom:1px solid var(--hair);}
.exp-when{font-family:var(--mono);font-size:13px;color:var(--faint);letter-spacing:.02em;padding-top:4px;}
.exp-role{font-family:var(--serif);font-size:24px;color:var(--moon);font-weight:500;}
.exp-org{font-family:var(--sans);font-size:13px;color:var(--glow);letter-spacing:.03em;margin-top:4px;}
.exp-desc{font-family:var(--body);font-size:16.5px;color:var(--dim);line-height:1.6;margin-top:12px;max-width:46em;}
.ph{color:var(--faint);font-style:italic;}

/* ============================================================
   PROJECTS — star cards
   ============================================================ */
.proj-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:18px;}
.card{position:relative;display:block;padding:26px 26px 22px;border:1px solid var(--hair);border-radius:14px;
  background:linear-gradient(160deg,rgba(27,37,80,.34),rgba(8,11,29,.28));overflow:hidden;
  transition:transform .3s var(--ease),border-color .3s,box-shadow .3s;}
.card::after{content:'';position:absolute;inset:0;background:radial-gradient(120px 120px at var(--mx,80%) var(--my,0%),rgba(143,180,255,.16),transparent 70%);
  opacity:0;transition:opacity .3s;pointer-events:none;}
.card:hover{transform:translateY(-4px);border-color:rgba(143,180,255,.5);box-shadow:0 16px 40px rgba(4,6,15,.6);}
.card:hover::after{opacity:1;}
.card .top{margin-bottom:13px;}
.card .nm{display:block;font-family:var(--serif);font-size:25px;color:var(--moon);font-weight:500;line-height:1.12;padding-right:52px;}
.card .star{position:absolute;top:24px;right:24px;display:inline-flex;align-items:center;gap:4px;
  font-family:var(--mono);font-size:12px;color:var(--gold);}
.card .star svg{fill:var(--gold);}
.card .desc{font-family:var(--body);font-size:16px;color:var(--dim);line-height:1.55;min-height:48px;}
.card .foot{display:flex;align-items:center;justify-content:space-between;margin-top:20px;}
.card .tag{font-family:var(--sans);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--violet);
  border:1px solid var(--hair);border-radius:999px;padding:4px 11px;}
.card .go{font-family:var(--sans);font-size:11px;letter-spacing:.06em;color:var(--faint);transition:color .2s;}
.card:hover .go{color:var(--glow);}

/* ============================================================
   AWARDS
   ============================================================ */
.awards{display:flex;flex-direction:column;}
.award{display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:22px;padding:22px 4px;
  border-bottom:1px solid var(--hair);transition:padding-left .25s var(--ease);}
.award:hover{padding-left:14px;}
.award .yr{font-family:var(--mono);font-size:13px;color:var(--faint);}
.award .ttl{font-family:var(--serif);font-size:clamp(20px,2.4vw,27px);color:var(--moon);font-weight:500;}
.award .ttl small{display:block;font-family:var(--body);font-size:14px;color:var(--dim);margin-top:3px;font-weight:400;}
.award .medal{font-family:var(--sans);font-size:11px;letter-spacing:.1em;text-transform:uppercase;
  color:var(--gold);border:1px solid rgba(240,210,138,.4);border-radius:999px;padding:5px 13px;white-space:nowrap;}

/* ============================================================
   PUBLICATIONS
   ============================================================ */
.pub{padding:24px 0;border-top:1px solid var(--hair);}
.pub:last-of-type{border-bottom:1px solid var(--hair);}
.pub .t{font-family:var(--serif);font-size:23px;color:var(--moon);font-weight:500;line-height:1.3;}
.pub .meta{font-family:var(--sans);font-size:13px;color:var(--dim);margin-top:8px;letter-spacing:.02em;}
.orcid-line{display:inline-flex;align-items:center;gap:10px;margin-bottom:30px;font-family:var(--mono);
  font-size:13px;color:var(--dim);border:1px solid var(--hair);border-radius:999px;padding:9px 16px;transition:border-color .2s,color .2s;}
.orcid-line:hover{border-color:var(--glow);color:var(--ink);}
.orcid-line .dotg{width:8px;height:8px;border-radius:50%;background:var(--gold);box-shadow:0 0 8px var(--gold);}

/* ============================================================
   CONTACT + footer
   ============================================================ */
.contact{text-align:center;}
.contact .big{font-family:var(--serif);font-size:clamp(40px,7vw,88px);font-weight:500;color:var(--moon);line-height:1;
  text-shadow:0 0 40px rgba(143,180,255,.35);}
.contact .sub{font-family:var(--body);font-style:italic;font-size:20px;color:var(--dim);margin-top:18px;}
.links{display:flex;flex-wrap:wrap;justify-content:center;gap:14px;margin-top:46px;}
.links a{display:inline-flex;flex-direction:column;align-items:center;gap:5px;min-width:150px;
  padding:20px 22px;border:1px solid var(--hair);border-radius:14px;background:rgba(16,22,55,.3);
  transition:transform .25s var(--ease),border-color .25s,background .25s;}
.links a:hover{transform:translateY(-4px);border-color:rgba(143,180,255,.5);background:rgba(27,37,80,.4);}
.links a .k{font-family:var(--sans);font-size:10px;letter-spacing:.2em;text-transform:uppercase;color:var(--glow);}
.links a .v{font-family:var(--mono);font-size:13px;color:var(--ink);}
footer{padding:50px 0 60px;text-align:center;font-family:var(--sans);font-size:11.5px;letter-spacing:.08em;
  color:var(--faint);border-top:1px solid var(--hair);margin-top:60px;}
footer .s{color:var(--violet);}

/* ============================================================
   responsive
   ============================================================ */
@media (max-width:760px){
  .nav-links{display:none;}
  .nav-links.open{display:flex;position:absolute;top:100%;right:16px;flex-direction:column;gap:14px;
    background:rgba(8,11,29,.95);backdrop-filter:blur(14px);padding:20px 26px;border:1px solid var(--hair);border-radius:14px;}
  .nav-toggle{display:flex;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:6px;}
  .nav-toggle span{width:22px;height:1.5px;background:var(--ink);display:block;}
  .about-grid{grid-template-columns:1fr;}
  .facts{border-left:0;border-top:1px solid var(--hair);padding-left:0;padding-top:26px;}
  .exp-item{grid-template-columns:1fr;gap:8px;}
  .path{gap:12px;padding:14px 18px;}
  .path .school .cn{font-size:18px;}
  #hero-cons{opacity:.5;}
  .moon{width:60px;height:60px;}
}