/* ============ TOKENS ============ */
:root{
  --bg:#FFFFFF;
  --bg-alt:#F5F6F9;
  --bg-deep:#0B1220;
  --ink:#0B1220;
  --ink-soft:#4A5166;
  --ink-faint:#9096A6;
  --line:#E6E8EE;
  --line-soft:#EFF1F5;
  --accent:#2952FF;
  --accent-deep:#1A36B8;
  --accent-soft:#EEF1FF;
  --accent-ink:#16205C;
  --good:#0F9D78;
  --good-soft:#E7F7F2;
  --warn:#B76E00;
  --warn-soft:#FDF3E2;
  --display:'Fraunces', serif;
  --body:'Inter', sans-serif;
  --mono:'IBM Plex Mono', monospace;
  --radius:14px;
  --radius-sm:8px;
  --maxw:1160px;
}

*{ box-sizing:border-box; margin:0; padding:0; }
html{ scroll-behavior:smooth; }
body{
  background:var(--bg); color:var(--ink); font-family:var(--body);
  font-size:16px; line-height:1.65; -webkit-font-smoothing:antialiased;
}
a{ color:inherit; text-decoration:none; }
img{ max-width:100%; display:block; }
::selection{ background:var(--accent); color:#fff; }

.wrap{ max-width:var(--maxw); margin:0 auto; padding:0 32px; }

/* ============ NAV ============ */
header.site-header{
  position:sticky; top:0; z-index:60;
  background:rgba(255,255,255,0.86); backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
nav.site-nav{
  max-width:var(--maxw); margin:0 auto; padding:18px 32px;
  display:flex; align-items:center; justify-content:space-between;
}
.brand{ display:flex; align-items:center; gap:10px; font-family:var(--display); font-weight:600; font-size:19px; }
.brand .mark{
  width:30px; height:30px; border-radius:8px; background:var(--ink);
  color:#fff; display:flex; align-items:center; justify-content:center;
  font-family:var(--mono); font-size:12px; font-weight:600; flex-shrink:0;
}
.nav-links{ display:flex; align-items:center; gap:8px; }
.nav-links a{
  font-family:var(--body); font-weight:500; font-size:14.5px; color:var(--ink-soft);
  padding:9px 14px; border-radius:100px; transition:all .22s cubic-bezier(.22,1,.36,1);
}
.nav-links a:hover{ color:var(--ink); background:var(--bg-alt); transform:translateY(-1px); }
.nav-links a.active{ color:var(--ink); background:var(--accent-soft); }
.nav-links a.resume-link{ display:inline-flex; align-items:center; gap:6px; color:var(--accent); font-weight:600; }
.nav-links a.resume-link:hover{ color:var(--accent-deep); background:var(--accent-soft); }
.nav-links a.resume-link svg{ flex-shrink:0; }
.nav-cta{
  font-family:var(--body); font-weight:600; font-size:14px; color:#fff !important;
  background:var(--ink); padding:10px 18px; border-radius:100px; transition:background .18s;
}
.nav-cta:hover{ background:var(--accent); }
.nav-toggle{ display:none; background:none; border:none; cursor:pointer; padding:6px; }
.nav-toggle span{ display:block; width:22px; height:2px; background:var(--ink); margin:5px 0; border-radius:2px; }

/* ============ BUTTONS ============ */
.btn{
  display:inline-flex; align-items:center; gap:8px; font-family:var(--body); font-weight:600;
  font-size:14.5px; padding:13px 24px; border-radius:100px; transition:all .2s; border:1px solid transparent;
}
.btn-primary{ background:var(--ink); color:#fff; }
.btn-primary:hover{ background:var(--accent); transform:translateY(-1px); }
.btn-outline{ border-color:var(--line); color:var(--ink); }
.btn-outline:hover{ border-color:var(--ink); }
.btn-sm{ padding:9px 16px; font-size:13.5px; }
.btn svg{ transition:transform .2s; }
.btn:hover svg{ transform:translate(2px,-2px); }

/* ============ TYPE HELPERS ============ */
.eyebrow{
  font-family:var(--mono); font-size:12.5px; letter-spacing:0.08em; text-transform:uppercase;
  color:var(--accent); display:flex; align-items:center; gap:10px; margin-bottom:16px;
}
.eyebrow::before{ content:''; width:22px; height:1.5px; background:var(--accent); }
h1,h2,h3,h4{ font-family:var(--display); font-weight:600; letter-spacing:-0.01em; color:var(--ink); }
.lede{ color:var(--ink-soft); font-size:18px; max-width:60ch; }

/* ============ PAGE HEADER (inner pages) ============ */
.page-header{ padding:64px 0 56px; border-bottom:1px solid var(--line); }
.page-header h1{ font-size:clamp(2rem, 4.4vw, 3rem); margin-bottom:16px; }
.page-header p{ color:var(--ink-soft); font-size:17px; max-width:64ch; }

section{ padding:88px 0; }
section.alt{ background:var(--bg-alt); }
.section-head{ margin-bottom:52px; }
.section-head h2{ font-size:clamp(1.6rem,3.2vw,2.3rem); margin-bottom:14px; }
.section-head p{ color:var(--ink-soft); max-width:60ch; font-size:16px; }

/* ============ HERO (home) ============ */
.hero{
  padding:96px 0 40px; display:grid; grid-template-columns:1.1fr 0.9fr; gap:48px; align-items:center;
  position:relative; --mx:50%; --my:30%;
}
.hero::before{
  content:''; position:absolute; inset:-40px -32px; pointer-events:none; z-index:0;
  background:radial-gradient(560px circle at var(--mx) var(--my), rgba(41,82,255,0.08), transparent 68%);
}
.hero > div:first-child, .hero .diagram-card{ position:relative; z-index:1; }

/* hero load-in sequence */
.hero > div:first-child > .eyebrow{ animation:heroIn .7s cubic-bezier(.22,1,.36,1) both; animation-delay:.05s; }
.hero > div:first-child > h1{ animation:heroIn .8s cubic-bezier(.22,1,.36,1) both; animation-delay:.16s; }
.hero > div:first-child > p.lede{ animation:heroIn .8s cubic-bezier(.22,1,.36,1) both; animation-delay:.30s; }
.hero > div:first-child > .hero-actions{ animation:heroIn .8s cubic-bezier(.22,1,.36,1) both; animation-delay:.42s; }
.hero .diagram-card{ animation:heroInScale .9s cubic-bezier(.22,1,.36,1) both; animation-delay:.24s; }

@keyframes heroIn{
  from{ opacity:0; transform:translateY(22px); }
  to{ opacity:1; transform:translateY(0); }
}
@keyframes heroInScale{
  from{ opacity:0; transform:translateY(26px) scale(.97); }
  to{ opacity:1; transform:translateY(0) scale(1); }
}
@keyframes pulse{ 0%,100%{opacity:1;} 50%{opacity:0.3;} }
.hero h1{ font-size:clamp(2.6rem,5.4vw,4rem); line-height:1.06; margin-bottom:22px; }
.hero h1 em{ font-style:italic; color:var(--accent); }
.hero p.lede{ margin-bottom:34px; }
.hero-actions{ display:flex; gap:14px; flex-wrap:wrap; }

/* pipeline diagram signature */
.diagram-card{
  background:var(--bg-deep); border-radius:20px; padding:32px 26px; position:relative; overflow:hidden;
  box-shadow:0 30px 70px -30px rgba(11,18,32,0.5); --mx:50%; --my:20%;
  transition:box-shadow .4s, transform .4s cubic-bezier(.22,1,.36,1);
}
.diagram-card::after{
  content:''; position:absolute; inset:0; pointer-events:none; opacity:0; transition:opacity .4s;
  background:radial-gradient(340px circle at var(--mx) var(--my), rgba(143,164,255,0.16), transparent 65%);
}
.diagram-card:hover::after{ opacity:1; }
.diagram-card:hover{ box-shadow:0 36px 80px -28px rgba(11,18,32,0.6); }
.diagram-card .diagram-label{ font-family:var(--mono); font-size:11.5px; color:#8891A6; letter-spacing:0.06em; margin-bottom:22px; text-transform:uppercase; }
.node-row{ display:flex; flex-direction:column; gap:0; }
.node{
  display:flex; align-items:center; gap:14px; padding:13px 0; position:relative;
}
.node .idx{
  font-family:var(--mono); font-size:11px; color:#5A6480; width:20px; flex-shrink:0;
}
.node .box{
  flex-grow:1; background:#151D30; border:1px solid #232C44; border-radius:10px; padding:12px 16px;
  transition:all .4s;
}
.node .box .name{ font-family:var(--body); font-weight:600; font-size:14px; color:#E7EAF2; }
.node .box .meta{ font-family:var(--mono); font-size:11.5px; color:#6E7890; margin-top:3px; }
.node.active .box{ border-color:var(--accent); background:#161F3C; box-shadow:0 0 0 1px rgba(41,82,255,0.25); transform:translateX(3px); }
.node.active .box .meta{ color:#8FA4FF; }
.node .connector{
  position:absolute; left:29px; top:100%; width:1px; height:0; background:#2A3450;
}
.node:not(:last-child) .connector{ height:14px; }
.node:not(:last-child) .connector::after{
  content:''; position:absolute; left:50%; top:-4px; width:6px; height:6px; border-radius:50%;
  background:var(--accent); transform:translateX(-50%); opacity:0;
  box-shadow:0 0 10px 3px rgba(41,82,255,.85);
  animation:flowPulse 7s linear infinite;
}
.node:nth-child(1) .connector::after{ animation-delay:0s; }
.node:nth-child(2) .connector::after{ animation-delay:1.4s; }
.node:nth-child(3) .connector::after{ animation-delay:2.8s; }
.node:nth-child(4) .connector::after{ animation-delay:4.2s; }
@keyframes flowPulse{
  0%{ opacity:0; top:-4px; }
  6%{ opacity:1; }
  85%{ opacity:1; }
  100%{ opacity:0; top:15px; }
}

/* ============ STATS ROW ============ */
.stats-row{ display:grid; grid-template-columns:repeat(4,1fr); border:1px solid var(--line); border-radius:var(--radius); overflow:hidden; }
.stat{ padding:26px 22px; border-right:1px solid var(--line); }
.stat:last-child{ border-right:none; }
.stat .num{ font-family:var(--display); font-size:30px; font-weight:600; margin-bottom:4px; }
.stat .lbl{ font-size:13px; color:var(--ink-soft); }

/* ============ FEATURED / CARDS ============ */
.feature-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:20px; }
.card{
  background:#fff; border:1px solid var(--line); border-radius:var(--radius); padding:26px;
  transition:all .25s; display:flex; flex-direction:column; height:100%;
}
.card:hover{ border-color:var(--accent); transform:translateY(-4px); box-shadow:0 20px 40px -24px rgba(41,82,255,0.25); }
.card-top{ display:flex; justify-content:space-between; align-items:flex-start; gap:10px; margin-bottom:14px; }
.card h3{ font-size:18px; }
.badge{
  font-family:var(--mono); font-size:10.5px; text-transform:uppercase; letter-spacing:0.05em;
  padding:4px 10px; border-radius:100px; white-space:nowrap; flex-shrink:0;
}
.badge.prod{ color:var(--good); background:var(--good-soft); }
.badge.research{ color:var(--warn); background:var(--warn-soft); }
.badge.oss{ color:var(--accent); background:var(--accent-soft); }
.card p{ color:var(--ink-soft); font-size:14.5px; flex-grow:1; margin-bottom:18px; }
.chip-row{ display:flex; flex-wrap:wrap; gap:6px; margin-bottom:18px; }
.chip{
  font-family:var(--mono); font-size:11px; color:var(--ink-soft); background:var(--bg-alt);
  border:1px solid var(--line-soft); padding:4px 9px; border-radius:6px;
}
.card-link{
  font-family:var(--body); font-weight:600; font-size:13.5px; display:inline-flex; align-items:center; gap:6px;
  padding-top:16px; border-top:1px solid var(--line-soft); color:var(--ink); transition:color .2s;
}
.card-link:hover{ color:var(--accent); }

/* ============ EXPERIENCE TIMELINE ============ */
.timeline{ }
.tl-item{
  display:grid; grid-template-columns:180px 1fr; gap:36px; padding:40px 0; border-top:1px solid var(--line);
}
.tl-item:first-child{ border-top:none; padding-top:0; }
.tl-meta{ font-family:var(--mono); font-size:13px; color:var(--ink-faint); }
.tl-meta .period{ color:var(--ink-soft); font-weight:600; margin-bottom:10px; }
.tl-tag{
  display:inline-flex; align-items:center; gap:6px; font-family:var(--mono); font-size:11px;
  color:var(--good); background:var(--good-soft); padding:4px 10px; border-radius:100px; margin-top:12px;
}
.tl-tag .dot{ width:5px; height:5px; border-radius:50%; background:var(--good); animation:pulse 2.2s infinite; }
.tl-body h3{ font-size:21px; margin-bottom:4px; }
.tl-body .company{ color:var(--ink-soft); font-size:14.5px; margin-bottom:18px; }
.tl-body ul{ list-style:none; }
.tl-body li{ position:relative; padding-left:22px; margin-bottom:12px; color:var(--ink-soft); font-size:15px; }
.tl-body li::before{ content:'—'; position:absolute; left:0; color:var(--accent); font-weight:700; }
.tl-body li b{ color:var(--ink); font-weight:600; }

/* ============ SKILLS PANELS ============ */
.skill-grid{ display:grid; grid-template-columns:repeat(2,1fr); gap:16px; }
.skill-panel{ background:#fff; border:1px solid var(--line); border-radius:var(--radius); padding:26px 28px; }
.skill-panel .head{ display:flex; align-items:center; gap:10px; margin-bottom:16px; font-weight:600; font-size:15px; }
.skill-panel .head .idot{ width:8px; height:8px; border-radius:50%; }
.skill-panel .tags{ display:flex; flex-wrap:wrap; gap:8px; }
.skill-panel .tags span{
  font-family:var(--mono); font-size:12.5px; padding:6px 12px; border-radius:7px;
  background:var(--bg-alt); border:1px solid var(--line-soft); color:var(--ink);
}

/* ============ FILTER TABS (projects page) ============ */
.filter-row{ display:flex; gap:10px; margin-bottom:36px; flex-wrap:wrap; }
.filter-btn{
  font-family:var(--body); font-weight:600; font-size:13.5px; padding:9px 18px; border-radius:100px;
  border:1px solid var(--line); color:var(--ink-soft); cursor:pointer; background:#fff; transition:all .18s;
}
.filter-btn:hover{ border-color:var(--ink); color:var(--ink); }
.filter-btn.active{ background:var(--ink); color:#fff; border-color:var(--ink); }
.proj-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:20px; }
.proj-grid .card{ transition:opacity .28s ease, transform .28s ease, border-color .25s, box-shadow .25s; }
.proj-grid .card.fade-out{ opacity:0; transform:scale(.94); pointer-events:none; }
.proj-grid .card.hidden{ display:none; }

/* ============ ACHIEVEMENT TILES ============ */
.metrics{ display:grid; grid-template-columns:repeat(4,1fr); gap:16px; }
.metric{ background:#fff; border:1px solid var(--line); border-radius:var(--radius); padding:24px 20px; }
.metric .num{ font-family:var(--display); font-size:26px; font-weight:600; color:var(--accent); margin-bottom:6px; }
.metric .lbl{ font-size:13px; color:var(--ink-soft); line-height:1.5; }

/* ============ EDUCATION ROW ============ */
.edu-row{ display:flex; justify-content:space-between; align-items:baseline; gap:14px; flex-wrap:wrap; padding:22px 0; border-top:1px solid var(--line); }
.edu-row:first-child{ border-top:none; padding-top:0; }
.edu-row h4{ font-size:17px; }
.edu-row .sub{ color:var(--ink-soft); font-size:14px; margin-top:2px; }
.edu-row .meta{ font-family:var(--mono); font-size:13px; color:var(--ink-faint); text-align:right; }

/* ============ CTA BANNER ============ */
.cta-banner{
  background:var(--bg-deep); border-radius:24px; padding:64px 56px; text-align:center; color:#fff;
  position:relative; overflow:hidden; --mx:30%; --my:20%;
}
.cta-banner::before{
  content:''; position:absolute; inset:0; transition:background .3s;
  background:radial-gradient(circle at var(--mx) var(--my), rgba(41,82,255,0.35), transparent 55%);
}
.cta-banner *{ position:relative; }
.cta-banner .eyebrow{ color:#8FA4FF; justify-content:center; }
.cta-banner .eyebrow::before{ background:#8FA4FF; }
.cta-banner h2{ color:#fff; font-size:clamp(1.8rem,4vw,2.6rem); margin-bottom:16px; }
.cta-banner p{ color:#B7BFD6; max-width:52ch; margin:0 auto 32px; font-size:16px; }
.cta-actions{ display:flex; gap:14px; justify-content:center; flex-wrap:wrap; }
.cta-banner .btn-primary{ background:#fff; color:var(--bg-deep); }
.cta-banner .btn-primary:hover{ background:var(--accent); color:#fff; }
.cta-banner .btn-outline{ border-color:rgba(255,255,255,0.28); color:#fff; }
.cta-banner .btn-outline:hover{ border-color:#fff; }

/* ============ CONTACT PAGE ============ */
.contact-grid{ display:grid; grid-template-columns:1fr 1fr; gap:20px; }
.contact-card{
  background:#fff; border:1px solid var(--line); border-radius:var(--radius); padding:30px;
  display:flex; align-items:center; gap:18px; transition:all .2s;
}
.contact-card:hover{ border-color:var(--accent); transform:translateY(-3px); }
.contact-card .ic{
  width:46px; height:46px; border-radius:12px; background:var(--accent-soft); color:var(--accent-ink);
  display:flex; align-items:center; justify-content:center; flex-shrink:0;
}
.contact-card .lbl{ font-size:12.5px; color:var(--ink-faint); font-family:var(--mono); margin-bottom:3px; }
.contact-card .val{ font-weight:600; font-size:15.5px; }

/* ============ FOOTER ============ */
footer.site-footer{ border-top:1px solid var(--line); padding:36px 0; }
footer.site-footer .wrap{ display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:14px; }
footer.site-footer p{ font-family:var(--mono); font-size:12.5px; color:var(--ink-faint); }
.footer-links{ display:flex; gap:20px; }
.footer-links a{ font-size:13.5px; color:var(--ink-soft); transition:color .18s; }
.footer-links a:hover{ color:var(--accent); }

/* ============ REVEAL ANIM ============ */
.reveal{ opacity:0; transform:translateY(20px) scale(.985); transition:opacity .7s cubic-bezier(.22,1,.36,1), transform .7s cubic-bezier(.22,1,.36,1); }
.reveal.in{ opacity:1; transform:translateY(0) scale(1); }

/* ============ MOTION UTILITIES ============ */
.scroll-progress{
  position:fixed; top:0; left:0; height:3px; width:100%;
  background:var(--accent); transform:scaleX(0); transform-origin:0 50%;
  z-index:200; opacity:.85;
}

.card, .contact-card, .skill-panel{ will-change:transform; }

.num-pop{ animation:numPop .45s cubic-bezier(.22,1,.36,1); }
@keyframes numPop{ 0%{ transform:scale(1); } 45%{ transform:scale(1.14); } 100%{ transform:scale(1); } }

/* Progressive-enhancement cross-page fade (supported browsers only; no-op elsewhere) */
@view-transition{ navigation:auto; }

/* ============ RESPONSIVE ============ */
@media (max-width: 920px){
  .hero{ grid-template-columns:1fr; padding-top:56px; }
  .feature-grid, .proj-grid{ grid-template-columns:1fr 1fr; }
  .skill-grid, .contact-grid{ grid-template-columns:1fr; }
  .stats-row{ grid-template-columns:1fr 1fr; }
  .metrics{ grid-template-columns:1fr 1fr; }
  .tl-item{ grid-template-columns:1fr; gap:14px; }
  .nav-links{ display:none; }
  .nav-toggle{ display:block; }
  .cta-banner{ padding:44px 28px; }
}
@media (max-width: 640px){
  .feature-grid, .proj-grid{ grid-template-columns:1fr; }
  .stats-row{ grid-template-columns:1fr 1fr; }
  .stat{ border-bottom:1px solid var(--line); }
  .metrics{ grid-template-columns:1fr 1fr; }
}

@media (prefers-reduced-motion: reduce){
  *{ animation:none !important; transition:none !important; }
}