:root{
  --bg:#ffffff;
  --surface:#f7f7f8;
  --surface-2:#ffffff;
  --border:#e6e6ea;
  --text:#1a1a1e;
  --muted:#6b6b76;
  --accent:#2d6cdf;
  --accent-soft:#eaf1fe;
  --chip-link:#2864d2; /* darker than --accent to pass WCAG AA on --accent-soft */
  --tag:#eef0f4;
  --tag-text:#3a3a44;
  --shadow:0 1px 2px rgba(20,20,30,.04),0 8px 24px rgba(20,20,30,.06);
  --radius:14px;
  --maxw:820px;
}
:root[data-theme="dark"]{
  --bg:#0e0f13;
  --surface:#16181f;
  --surface-2:#1b1e27;
  --border:#282b36;
  --text:#e9e9ef;
  --muted:#9a9aa8;
  --accent:#6ea0ff;
  --accent-soft:#1a2337;
  --chip-link:#6ea0ff; /* passes AA on dark --accent-soft (6:1) */
  --tag:#242833;
  --tag-text:#c3c7d4;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px rgba(0,0,0,.35);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  line-height:1.6;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}

/* keyboard focus visibility (a11y) — shown only for keyboard nav, not mouse clicks */
a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,
select:focus-visible,[tabindex]:focus-visible,.media-card:focus-visible,.chip.link:focus-visible{
  outline:2px solid var(--accent);
  outline-offset:2px;
  border-radius:6px;
}

/* skip-to-content link — visible only when focused via keyboard */
.skip-link{
  position:absolute;left:8px;top:-52px;z-index:100;
  background:var(--accent);color:#fff;
  padding:9px 15px;border-radius:9px;font-weight:600;font-size:.9rem;
  transition:top .15s ease;
}
.skip-link:focus{top:8px;text-decoration:none;outline:2px solid var(--text);outline-offset:2px}
#content:focus{outline:none}

/* respect users who prefer reduced motion */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
  }
}

/* nav */
nav{
  position:sticky;top:0;z-index:50;
  backdrop-filter:saturate(180%) blur(12px);
  background:color-mix(in srgb,var(--bg) 80%,transparent);
  border-bottom:1px solid var(--border);
}
.nav-inner{
  max-width:var(--maxw);margin:0 auto;padding:12px 20px;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
}
.brand{font-weight:700;letter-spacing:-.01em}
.brand a{color:var(--text)}
.brand a:hover{color:var(--accent);text-decoration:none}
.nav-links{display:flex;gap:20px;align-items:center}
.nav-links a{color:var(--muted);font-size:.92rem;font-weight:500}
.nav-links a:hover{color:var(--text);text-decoration:none}
.nav-links a.active{color:var(--accent)}
.theme-btn{
  background:var(--surface);border:1px solid var(--border);color:var(--text);
  width:34px;height:34px;border-radius:9px;cursor:pointer;font-size:1rem;
  display:inline-flex;align-items:center;justify-content:center;transition:.15s;
}
.theme-btn:hover{background:var(--accent-soft)}
.nav-right{display:flex;align-items:center;gap:10px}
.nav-toggle{
  display:none;background:var(--surface);border:1px solid var(--border);color:var(--text);
  width:34px;height:34px;border-radius:9px;cursor:pointer;transition:.15s;
  align-items:center;justify-content:center;
}
.nav-toggle:hover{background:var(--accent-soft)}
.nav-toggle svg{width:18px;height:18px}
@media(max-width:560px){
  .nav-inner{position:relative;padding:12px 16px}
  .nav-toggle{display:inline-flex}
  .nav-links{
    display:none;position:absolute;top:100%;left:0;right:0;z-index:60;
    flex-direction:column;align-items:stretch;gap:0;
    background:var(--bg);border-bottom:1px solid var(--border);box-shadow:var(--shadow);
    padding:4px 16px 10px;
  }
  nav.open .nav-links{display:flex}
  .nav-links a{padding:12px 2px;font-size:1rem;border-top:1px solid var(--border)}
  .nav-links a:first-child{border-top:none}
}

/* layout */
main{max-width:var(--maxw);margin:0 auto;padding:0 20px 80px}
section{padding-top:52px;scroll-margin-top:72px}
.eyebrow{
  text-transform:uppercase;letter-spacing:.12em;font-size:.72rem;
  font-weight:600;color:var(--muted);margin-bottom:14px;
}
h2{font-size:1.45rem;font-weight:700;letter-spacing:-.02em;margin:0 0 22px}
/* page-title h1 styled like h2 (used on utility pages so each page has one h1) */
.sect-title{font-size:1.45rem;font-weight:700;letter-spacing:-.02em;margin:0 0 22px}

/* page header (secondary pages) */
.page-head{padding-top:56px}
.page-head h1{font-size:2rem;line-height:1.1;letter-spacing:-.03em;margin:0 0 8px}
.back-link{display:inline-block;margin-top:14px;font-size:.9rem;font-weight:500}

/* hero */
.hero{display:flex;gap:34px;align-items:center;padding-top:56px;position:relative}
.hero-emoji{
  display:inline-block;margin-left:12px;vertical-align:middle;
  font-size:1.7rem;line-height:1;cursor:pointer;user-select:none;z-index:3;position:relative;
  transition:transform .3s cubic-bezier(.22,1,.36,1);will-change:transform;
}
.hero-photo{flex:0 0 168px}
.hero-photo img{
  width:168px;height:168px;object-fit:cover;border-radius:20px;
  box-shadow:var(--shadow);border:1px solid var(--border);
}
.hero h1{font-size:2.15rem;line-height:1.1;letter-spacing:-.03em;margin:0 0 6px}
.hero .role{font-size:1.06rem;color:var(--muted);margin:0 0 16px}
.hero .role b{color:var(--text);font-weight:600}
.links{display:flex;flex-wrap:wrap;gap:10px;margin-top:4px}
.links a{
  display:inline-flex;align-items:center;gap:7px;
  background:var(--surface);border:1px solid var(--border);color:var(--text);
  padding:7px 13px;border-radius:10px;font-size:.9rem;font-weight:500;transition:.15s;
}
.links a:hover{background:var(--accent-soft);border-color:var(--accent);text-decoration:none}
.links a svg{width:16px;height:16px;flex:0 0 16px}
.links a.i-mail svg{color:#ea4335}
.links a.i-cv svg{color:#1f9d63}
.links a.i-scholar svg{color:#4285f4}
.links a.i-linkedin svg{color:#0a66c2}
.links a.i-github svg{color:#181717}
:root[data-theme="dark"] .links a.i-github svg{color:#e9e9ef}
@media(max-width:600px){
  .hero{flex-direction:column;text-align:center;gap:22px;padding-top:40px}
  .links{justify-content:center}
}

.prose p{color:var(--text);margin:0 0 14px}
.prose{max-width:70ch;margin-top:26px}

/* news */
.news{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.news li{
  display:flex;gap:14px;align-items:baseline;
  background:var(--surface);border:1px solid var(--border);
  border-radius:12px;padding:12px 16px;
}
.news .date{color:var(--muted);font-weight:600;font-size:.82rem;white-space:nowrap;min-width:64px}

/* publications */
.pub{
  display:grid;grid-template-columns:104px 1fr;gap:18px;
  padding:18px;border:1px solid var(--border);border-radius:var(--radius);
  background:var(--surface-2);box-shadow:var(--shadow);margin-bottom:14px;transition:.15s;
}
.pub:hover{border-color:var(--accent);transform:translateY(-1px)}
.venue-tag{
  --vt:var(--accent);--vtbg:var(--accent-soft);
  align-self:start;
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;
  min-height:64px;padding:10px 6px;text-align:center;
  background:var(--vtbg);color:var(--vt);
  border:1px solid color-mix(in srgb,var(--vt) 32%,transparent);border-radius:12px;
  font-weight:700;font-size:.82rem;line-height:1.15;
  overflow-wrap:anywhere;hyphens:auto;
}
.venue-tag .yr{
  display:block;color:var(--muted);font-weight:600;font-size:.82rem;letter-spacing:.01em;margin:0;
}
.venue-tag .ty{
  display:block;margin-top:2px;font-size:.6rem;font-weight:700;letter-spacing:.09em;
  text-transform:uppercase;color:var(--vt);opacity:.75;
}
.venue-tag[data-type="journal"]{--vt:#2d6cdf;--vtbg:rgba(45,108,223,.12)}
.venue-tag[data-type="conf"]{--vt:#1f9d63;--vtbg:rgba(31,157,99,.13)}
.venue-tag[data-type="workshop"]{--vt:#8a5cf6;--vtbg:rgba(138,92,246,.13)}
.venue-tag[data-type="preprint"]{--vt:#7b7b86;--vtbg:rgba(123,123,134,.14)}
.venue-tag[data-type="review"]{--vt:#e0872f;--vtbg:rgba(224,135,47,.13)}
.venue-tag[data-type="thesis"]{--vt:#c9821a;--vtbg:rgba(201,130,26,.14)}
:root[data-theme="dark"] .venue-tag[data-type="journal"]{--vt:#7aa8ff}
:root[data-theme="dark"] .venue-tag[data-type="conf"]{--vt:#4fd39b}
:root[data-theme="dark"] .venue-tag[data-type="workshop"]{--vt:#b596ff}
:root[data-theme="dark"] .venue-tag[data-type="preprint"]{--vt:#b0b0bd}
:root[data-theme="dark"] .venue-tag[data-type="review"]{--vt:#ffb066}
:root[data-theme="dark"] .venue-tag[data-type="thesis"]{--vt:#e6ad4f}
.pub-title{font-weight:600;font-size:1.02rem;letter-spacing:-.01em;margin:0 0 4px}
.pub-authors{color:var(--muted);font-size:.9rem;margin:0 0 4px}
.pub-authors b{color:var(--text)}
.pub-venue{color:var(--muted);font-size:.88rem;font-style:italic}
.pub-meta{margin-top:8px;display:flex;flex-wrap:wrap;gap:8px}
.chip{
  font-size:.76rem;font-weight:600;padding:3px 9px;border-radius:999px;
  background:var(--tag);color:var(--tag-text);
}
.chip.link{background:var(--accent-soft);color:var(--chip-link)}
.subhead{font-size:.8rem;font-weight:600;text-transform:uppercase;letter-spacing:.1em;color:var(--muted);margin:26px 0 14px}
@media(max-width:520px){
  .pub{grid-template-columns:1fr;gap:12px}
  .venue-tag{justify-self:start;flex-direction:row;gap:6px;min-height:auto;padding:6px 12px}
  .venue-tag .yr{display:inline;margin:0}
}

/* media */
.media{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.media li{
  background:var(--surface);border:1px solid var(--border);
  border-radius:12px;padding:14px 16px;
}
.media .outlet{font-weight:600;font-size:1rem}
.media .outlet a{color:var(--text)}
.media .outlet a:hover{color:var(--accent)}
.media .desc{color:var(--muted);font-size:.9rem;margin-top:2px}
.media .region{color:var(--muted);font-size:.78rem;font-weight:600;float:right}
.media-note{color:var(--muted);font-size:.9rem;margin:-6px 0 18px;max-width:70ch}

/* media preview cards */
.media-grid{
  list-style:none;padding:0;margin:0 0 8px;
  display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px;
}
.media-card{
  display:flex;flex-direction:column;gap:9px;height:100%;
  padding:16px;border:1px solid var(--border);border-radius:14px;
  background:var(--surface-2);box-shadow:var(--shadow);transition:.15s;
}
a.media-card:hover{border-color:var(--accent);transform:translateY(-2px);text-decoration:none}
.media-card .thumb{
  width:100%;aspect-ratio:16/9;object-fit:cover;
  border-radius:10px;background:var(--surface);border:1px solid var(--border);display:block;
}
.media-card .thumb-ph{
  width:100%;aspect-ratio:16/9;border-radius:10px;border:1px solid var(--border);
  display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--accent-soft),var(--surface));
}
.media-card .thumb-ph img{width:54px;height:54px;border-radius:13px;border:1px solid var(--border);background:var(--surface);object-fit:contain}
.media-card .head{display:flex;align-items:center;gap:10px}
.media-card .fav{
  width:30px;height:30px;border-radius:7px;flex:0 0 30px;
  background:var(--surface);border:1px solid var(--border);object-fit:contain;
}
.media-card .name{font-weight:600;font-size:.98rem;color:var(--text);line-height:1.2}
.media-card .desc{color:var(--muted);font-size:.85rem;line-height:1.45}
.media-card .region{color:var(--muted);font-size:.74rem;font-weight:600;margin-top:auto}
.media-card.pending{opacity:.72}
.media-card .badge{color:var(--muted);font-weight:400;font-size:.78rem}

/* awards */
.awards{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.awards li{
  background:var(--surface);border:1px solid var(--border);border-radius:12px;
  padding:12px 16px;display:flex;gap:12px;align-items:center;
}
.awards .medal{font-size:1.1rem}

/* timeline (phased, parallel internships) — breaks out wider than the text column */
.gt{position:relative;left:50%;transform:translateX(-50%);width:min(1160px,94vw);height:250px;margin:18px 0 8px}
.gt-line{position:absolute;left:5%;right:5%;top:176px;height:2px;background:var(--border);z-index:0}
.gt-band{position:absolute;top:136px;height:80px;z-index:0}
.gt-band.iitb{background:color-mix(in srgb,#2d6cdf 13%,transparent);border:1.5px solid color-mix(in srgb,#2d6cdf 34%,transparent);border-right:none;border-radius:40px 0 0 40px}
.gt-band.phd{background:color-mix(in srgb,#c28e0e 15%,transparent);border:1.5px solid color-mix(in srgb,#c28e0e 40%,transparent);border-left:none;border-radius:0 40px 40px 0}

.gt-node{position:absolute;width:100px;transform:translateX(-50%);text-align:center;display:flex;flex-direction:column;align-items:center;z-index:1}
.gt-node.main{top:140px}
.gt-node.gi{bottom:107px;width:92px}

.g-chip{width:72px;height:72px;border-radius:17px;background:#fff;border:1px solid var(--border);display:flex;align-items:center;justify-content:center;box-shadow:var(--shadow)}
.g-chip img{width:50px;height:50px;object-fit:contain}
.g-nm{font-size:.79rem;font-weight:600;color:var(--text);margin-top:7px;line-height:1.15}
.g-yr{font-size:.68rem;font-weight:700;color:var(--muted);line-height:1.25}
.gt-node.main .g-yr{color:var(--muted)}

.gt-node.gi .g-chip{width:58px;height:58px;border-radius:15px}
.gt-node.gi .g-chip img{width:39px;height:39px}
.gt-node.gi .g-nm{margin-top:0;font-size:.74rem}
.gt-node.gi .g-yr{font-size:.62rem;margin-bottom:6px}
.gt-node.gi .stem{position:relative;width:2px;height:30px;margin-top:7px;background:color-mix(in srgb,var(--c) 55%,transparent)}
.gt-node.gi .stem::after{content:"";position:absolute;left:50%;bottom:-4px;transform:translateX(-50%);width:9px;height:9px;border-radius:50%;background:var(--c);border:2px solid var(--bg)}
.gt-node.gi.iitb{--c:#2d6cdf}
.gt-node.gi.iitb .g-chip{border-color:color-mix(in srgb,#2d6cdf 45%,var(--border))}
.gt-node.gi.phd{--c:#c28e0e}
.gt-node.gi.phd .g-chip{border-color:color-mix(in srgb,#c28e0e 50%,var(--border))}
:root[data-theme="dark"] .gt-node.gi.iitb{--c:#7aa8ff}
:root[data-theme="dark"] .gt-node.gi.phd{--c:#e6b84f}

@media(max-width:640px){
  .gt-scroll{overflow-x:auto;overflow-y:hidden;-webkit-overflow-scrolling:touch;margin:0 -16px;padding:6px 16px 10px}
  .gt-scroll::-webkit-scrollbar{height:5px}
  .gt-scroll::-webkit-scrollbar-thumb{background:var(--border);border-radius:99px}
  .gt{height:220px;width:860px;min-width:860px;position:relative;left:auto;transform:none;margin:0}
  .gt-line{top:160px}
  .gt-band{top:128px;height:64px}
  .gt-band.iitb{border-radius:32px 0 0 32px}
  .gt-band.phd{border-radius:0 32px 32px 0}
  .gt-node.main{top:132px}
  .gt-node.gi{bottom:92px}
  .g-chip{width:56px;height:56px}.g-chip img{width:38px;height:38px}
  .gt-node.gi .g-chip{width:46px;height:46px}.gt-node.gi .g-chip img{width:30px;height:30px}
  .g-nm,.gt-node.gi .g-nm{font-size:.64rem}
  .g-yr,.gt-node.gi .g-yr{font-size:.58rem}
  .gt-node{width:72px}.gt-node.gi{width:68px}
}

/* password-protected page */
.lockform{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-top:18px}
.lockform input{
  padding:10px 14px;border:1px solid var(--border);border-radius:10px;
  background:var(--surface-2);color:var(--text);font-size:.95rem;min-width:220px;
}
.lockform input:focus{border-color:var(--accent)}
.lockform button{
  padding:10px 18px;border:1px solid var(--accent);border-radius:10px;cursor:pointer;
  background:var(--accent);color:#fff;font-size:.95rem;font-weight:600;transition:.15s;
}
.lockform button:hover{filter:brightness(1.06)}
.lockerr{color:#e0533f;font-size:.9rem;font-weight:500}

footer{
  max-width:var(--maxw);margin:0 auto;padding:28px 20px 48px;
  color:var(--muted);font-size:.82rem;text-align:center;border-top:1px solid var(--border);
}
.secret-dot{color:inherit;text-decoration:none;cursor:default}
.secret-dot:hover{color:var(--accent)}

/* paper figures */
.paper-fig{margin:16px 0 24px}
.paper-fig img{display:block;width:100%;height:auto;border:1px solid var(--border);border-radius:12px;background:var(--surface-2)}
.paper-fig figcaption{color:var(--muted);font-size:.82rem;margin-top:8px;line-height:1.5}

/* visitor globe */
.globe{width:100%;min-height:360px;border:1px solid var(--border);border-radius:16px;overflow:hidden;background:#05070d}
.vlist{color:var(--muted);font-size:.85rem;margin:14px 0 20px;line-height:1.9;word-spacing:.1em}

/* python playground */
.py-demo{margin:18px 0 6px}
.py-code{
  width:100%;box-sizing:border-box;min-height:200px;resize:vertical;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.88rem;line-height:1.5;
  padding:14px 16px;border:1px solid var(--border);border-radius:12px;
  background:var(--surface-2);color:var(--text);tab-size:4;
}
.py-code:focus{border-color:var(--accent)}
.py-bar{display:flex;align-items:center;gap:12px;margin:10px 0}
.py-run{
  padding:9px 18px;border:1px solid var(--accent);border-radius:10px;cursor:pointer;
  background:var(--accent);color:#fff;font-weight:600;font-size:.9rem;transition:.15s;
}
.py-run:hover{filter:brightness(1.06)}
.py-run:disabled{opacity:.6;cursor:progress}
.py-status{color:var(--muted);font-size:.85rem}
.py-fig{margin:8px 0}
.py-fig img{display:block;max-width:100%;border:1px solid var(--border);border-radius:12px;background:var(--surface-2)}
.py-out{
  white-space:pre-wrap;word-break:break-word;min-height:60px;margin:0;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.86rem;line-height:1.5;
  padding:14px 16px;border:1px solid var(--border);border-radius:12px;
  background:var(--surface);color:var(--text);
}

/* playful "are you sure?" theme-switch nag modal */
.theme-modal-backdrop{
  position:fixed;inset:0;z-index:200;display:flex;align-items:center;justify-content:center;
  padding:20px;background:rgba(8,10,16,.55);backdrop-filter:blur(3px);
  animation:tmFade .15s ease;
}
.theme-modal{
  background:var(--surface-2);color:var(--text);border:1px solid var(--border);
  border-radius:16px;box-shadow:var(--shadow);max-width:390px;width:100%;
  padding:22px 22px 18px;text-align:center;animation:tmPop .18s cubic-bezier(.22,1,.36,1);
}
.theme-modal .tm-step{
  color:var(--muted);font-size:.7rem;font-weight:600;
  text-transform:uppercase;letter-spacing:.11em;margin:0 0 8px;
}
.theme-modal h3{font-size:1.12rem;line-height:1.4;margin:0 0 18px;font-weight:700;letter-spacing:-.01em}
.tm-row{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.tm-row button{
  padding:9px 16px;border-radius:10px;font-size:.9rem;font-weight:600;
  cursor:pointer;transition:.15s;border:1px solid var(--border);
}
.tm-no{background:var(--accent);color:#fff;border-color:var(--accent)}        /* "keep dark" = prominent */
.tm-no:hover{filter:brightness(1.07)}
.tm-yes{background:var(--surface);color:var(--muted)}                         /* "go light" = quiet */
.tm-yes:hover{background:var(--accent-soft);color:var(--text)}
@keyframes tmFade{from{opacity:0}to{opacity:1}}
@keyframes tmPop{from{opacity:0;transform:translateY(8px) scale(.97)}to{opacity:1;transform:none}}