/* ============================================================
   Aayush Neupane · site styles
   Tokens → base → nav → home → article → utilities
   ============================================================ */

:root{
  --paper:#F6F7F8; --surface:#FFFFFF; --ink:#14171C; --ink-2:#333A44; --muted:#5A616B;
  --hair:#E5E7EB; --hair-2:#EEF0F2; --accent:#33409E; --accent-ink:#33409E;
  --accent-soft:rgba(51,64,158,.08); --tag:#EDEFF6; --code-bg:#F1F2F6; --code-ink:#2B3350;
  --maxw:960px; --readw:720px;
  --serif:"Charter","Newsreader","Iowan Old Style","Palatino Linotype",Palatino,Georgia,"Times New Roman",serif;
  --sans:"Inter","Helvetica Neue","Segoe UI",system-ui,-apple-system,Roboto,Arial,sans-serif;
  --mono:"SF Mono","JetBrains Mono","Fira Code",ui-monospace,Menlo,Consolas,monospace;
}
@media (prefers-color-scheme:dark){
  :root{--paper:#0E1116;--surface:#161A21;--ink:#E7EAF0;--ink-2:#C3C9D2;--muted:#8E96A2;
    --hair:#232833;--hair-2:#1C212A;--accent:#93A0F2;--accent-ink:#A6B1F6;--accent-soft:rgba(147,160,242,.12);
    --tag:#1B2130;--code-bg:#171C26;--code-ink:#C4CCE6;}
}
:root[data-theme="light"]{--paper:#F6F7F8;--surface:#FFFFFF;--ink:#14171C;--ink-2:#333A44;--muted:#5A616B;
  --hair:#E5E7EB;--hair-2:#EEF0F2;--accent:#33409E;--accent-ink:#33409E;--accent-soft:rgba(51,64,158,.08);
  --tag:#EDEFF6;--code-bg:#F1F2F6;--code-ink:#2B3350;}
:root[data-theme="dark"]{--paper:#0E1116;--surface:#161A21;--ink:#E7EAF0;--ink-2:#C3C9D2;--muted:#8E96A2;
  --hair:#232833;--hair-2:#1C212A;--accent:#93A0F2;--accent-ink:#A6B1F6;--accent-soft:rgba(147,160,242,.12);
  --tag:#1B2130;--code-bg:#171C26;--code-ink:#C4CCE6;}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--serif);
  font-size:17px;line-height:1.62;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
  transition:background .35s ease,color .35s ease}
a{color:var(--accent-ink);text-decoration:none}
.sans{font-family:var(--sans)}
.mono{font-family:var(--mono);font-size:.7rem;letter-spacing:.1em;text-transform:uppercase}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 clamp(20px,5vw,40px)}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

/* ---------- NAV ---------- */
header.nav{position:sticky;top:0;z-index:40;background:color-mix(in srgb,var(--paper) 85%,transparent);
  backdrop-filter:saturate(1.2) blur(10px);-webkit-backdrop-filter:saturate(1.2) blur(10px);
  border-bottom:1px solid transparent;transition:border-color .3s}
header.nav.scrolled{border-color:var(--hair)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:58px;font-family:var(--sans)}
.nav-name{font-weight:650;letter-spacing:-.01em;font-size:.98rem;color:var(--ink)}
.nav-name span{color:var(--muted);font-weight:400}
.nav-links{display:flex;align-items:center;gap:22px}
.nav-links a{color:var(--muted);font-size:.85rem;font-weight:500;font-family:var(--sans)}
.nav-links a:hover{color:var(--ink)}
.nav-links a.active{color:var(--ink)}
.toggle{width:34px;height:34px;border-radius:8px;border:1px solid var(--hair);background:var(--surface);
  color:var(--ink);cursor:pointer;display:grid;place-items:center;transition:border-color .2s;flex:0 0 auto}
.toggle:hover{border-color:var(--accent)}
@media(max-width:680px){.nav-links a{display:none}}

/* ---------- HOME LAYOUT ---------- */
.grid{display:grid;grid-template-columns:230px 1fr;gap:clamp(28px,5vw,60px);
  padding-top:clamp(34px,6vw,66px);padding-bottom:100px}
@media(max-width:760px){.grid{grid-template-columns:1fr;gap:34px}}

aside{align-self:start}
@media(min-width:761px){aside{position:sticky;top:80px}}
.avatar{width:118px;height:118px;border-radius:16px;object-fit:cover;display:block;
  border:1px solid var(--hair);box-shadow:0 6px 24px -12px rgba(20,23,28,.4)}
.who{font-family:var(--sans);font-weight:680;font-size:1.35rem;letter-spacing:-.02em;margin:18px 0 4px;line-height:1.15;color:var(--ink)}
.role{color:var(--ink-2);font-size:.95rem;line-height:1.45;margin-bottom:2px}
.affil{color:var(--muted);font-size:.9rem}
.avail{display:inline-flex;align-items:center;gap:8px;margin-top:14px;font-family:var(--mono);
  font-size:.63rem;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-2);
  background:var(--surface);border:1px solid var(--hair);border-radius:100px;padding:5px 11px}
.dot{width:7px;height:7px;border-radius:50%;background:#16A34A;box-shadow:0 0 0 0 rgba(22,163,74,.5);animation:pulse 2.6s infinite}
@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(22,163,74,.45)}70%{box-shadow:0 0 0 6px rgba(22,163,74,0)}100%{box-shadow:0 0 0 0 rgba(22,163,74,0)}}
.links{display:flex;flex-wrap:wrap;gap:7px;margin-top:20px}
.links a{width:36px;height:36px;border-radius:9px;display:grid;place-items:center;color:var(--muted);
  border:1px solid var(--hair);background:var(--surface);transition:.18s}
.links a:hover{color:var(--accent-ink);border-color:var(--accent);transform:translateY(-2px)}
.links a.cv{width:auto;padding:0 12px;gap:6px;font-family:var(--sans);font-size:.8rem;font-weight:600;color:var(--ink-2)}
.links a.cv:hover{color:var(--accent-ink)}
.links svg{width:17px;height:17px}
.side-label{font-family:var(--mono);font-size:.62rem;letter-spacing:.13em;text-transform:uppercase;
  color:var(--muted);margin:26px 0 10px}
.tags{display:flex;flex-wrap:wrap;gap:6px}
.tags span{font-family:var(--sans);font-size:.76rem;color:var(--ink-2);background:var(--tag);border-radius:6px;padding:3px 8px}

main{min-width:0}
section+section{margin-top:clamp(36px,5vw,56px)}
h2.sec{font-family:var(--sans);font-size:.76rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;
  color:var(--muted);margin:0 0 20px;padding-bottom:10px;border-bottom:1px solid var(--hair);
  display:flex;align-items:center;gap:10px}
h2.sec::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--accent);flex:0 0 auto}
.prose p{margin:0 0 16px;color:var(--ink-2)}
.prose p:last-child{margin-bottom:0}
.prose strong{color:var(--ink);font-weight:640}

/* news */
.news{list-style:none;margin:0;padding:0}
.news li{display:grid;grid-template-columns:96px 1fr;gap:14px;padding:11px 0;border-bottom:1px solid var(--hair-2);align-items:baseline}
.news li:last-child{border-bottom:0}
.news .date{font-family:var(--mono);font-size:.68rem;letter-spacing:.04em;color:var(--muted);text-transform:uppercase;padding-top:2px}
.news .what{color:var(--ink-2);font-size:.98rem}
@media(max-width:520px){.news li{grid-template-columns:1fr;gap:2px}}

/* publications */
.pub{display:grid;grid-template-columns:64px 1fr;gap:18px;padding:4px 0}
.pub .venue{font-family:var(--mono);font-size:.62rem;letter-spacing:.06em;text-transform:uppercase;
  color:#fff;background:var(--accent);border-radius:7px;height:64px;display:flex;flex-direction:column;
  align-items:center;justify-content:center;text-align:center;line-height:1.3;padding:6px}
:root[data-theme="dark"] .pub .venue{color:#0E1116}
@media (prefers-color-scheme:dark){.pub .venue{color:#0E1116}}
.pub h3{margin:0 0 5px;font-size:1.08rem;line-height:1.35;font-weight:640;letter-spacing:-.01em;color:var(--ink)}
.pub .authors{color:var(--muted);font-size:.92rem;margin:0 0 3px}
.pub .authors b{color:var(--ink);font-weight:640}
.pub .meta{color:var(--muted);font-size:.86rem;font-style:italic}
.pub .plinks{margin-top:8px;display:flex;gap:8px;flex-wrap:wrap}
.pub .plinks a{font-family:var(--sans);font-size:.76rem;font-weight:600;padding:3px 10px;border:1px solid var(--hair);
  border-radius:100px;color:var(--ink-2)}
.pub .plinks a:hover{border-color:var(--accent);color:var(--accent-ink)}

/* experience / education rows */
.rows{display:flex;flex-direction:column}
.row{display:grid;grid-template-columns:150px 1fr;gap:18px;padding:15px 0;border-bottom:1px solid var(--hair-2)}
.row:last-child{border-bottom:0}
.row .yr{font-family:var(--mono);font-size:.68rem;letter-spacing:.03em;color:var(--muted);text-transform:uppercase;padding-top:3px}
.row h3{margin:0;font-size:1.05rem;font-weight:640;letter-spacing:-.01em;color:var(--ink)}
.row .org{color:var(--accent-ink);font-weight:600;font-size:.96rem}
.row .loc{color:var(--muted);font-weight:400}
.row p{margin:7px 0 0;color:var(--ink-2);font-size:.96rem;line-height:1.55}
@media(max-width:520px){.row{grid-template-columns:1fr;gap:4px}.row .yr{order:-1}}

/* writing list */
.writing{list-style:none;margin:0;padding:0}
.writing li{padding:14px 0;border-bottom:1px solid var(--hair-2)}
.writing li:last-child{border-bottom:0}
.writing a.wl{display:flex;align-items:baseline;gap:14px;flex-wrap:wrap}
.writing .wdate{font-family:var(--mono);font-size:.66rem;letter-spacing:.04em;color:var(--muted);text-transform:uppercase;min-width:74px}
.writing .wtitle{font-size:1.06rem;font-weight:640;letter-spacing:-.01em;color:var(--ink);line-height:1.35}
.writing a.wl:hover .wtitle{color:var(--accent-ink)}
.writing .cat{font-family:var(--sans);font-size:.7rem;font-weight:600;color:var(--accent-ink);
  background:var(--accent-soft);border-radius:100px;padding:2px 9px}
.writing .wsum{margin:6px 0 0 88px;color:var(--muted);font-size:.9rem;line-height:1.5}
@media(max-width:520px){.writing .wsum{margin-left:0}}
.more{display:inline-flex;align-items:center;gap:6px;margin-top:16px;font-family:var(--sans);
  font-size:.82rem;font-weight:600;color:var(--accent-ink);transition:gap .2s}
.more:hover{gap:10px}
.more svg{width:15px;height:15px}

/* projects */
.projs{display:grid;grid-template-columns:1fr 1fr;gap:2px 26px}
@media(max-width:600px){.projs{grid-template-columns:1fr}}
.proj{padding:13px 0;border-bottom:1px solid var(--hair-2)}
.proj h3{margin:0 0 3px;font-size:1rem;font-weight:640;display:flex;align-items:center;gap:7px}
.proj h3 a{color:var(--ink)}
.proj h3 a:hover{color:var(--accent-ink)}
.proj h3 .arw{color:var(--muted);transition:transform .2s}
.proj:hover h3 .arw{transform:translate(2px,-2px);color:var(--accent-ink)}
.proj p{margin:0;color:var(--muted);font-size:.9rem;line-height:1.5}

/* teaching / tutorials */
.teach-intro{color:var(--ink-2);margin:0 0 22px;font-size:.98rem;max-width:66ch}
.teach-intro .ai{color:var(--muted);font-style:italic}
.courses{display:grid;grid-template-columns:1fr 1fr;gap:12px}
@media(max-width:600px){.courses{grid-template-columns:1fr}}
a.course{display:flex;flex-direction:column;gap:8px;background:var(--surface);border:1px solid var(--hair);
  border-radius:14px;padding:18px 20px;box-shadow:0 1px 2px rgba(20,23,28,.04);
  transition:transform .2s ease,border-color .2s ease,box-shadow .25s ease}
a.course:hover{transform:translateY(-3px);border-color:color-mix(in srgb,var(--accent) 42%,var(--hair));
  box-shadow:0 12px 28px -14px rgba(20,23,28,.28)}
:root[data-theme="dark"] a.course:hover{box-shadow:0 14px 30px -16px rgba(0,0,0,.7)}
.course-top{display:flex;align-items:center;gap:10px}
.course .subj{font-family:var(--mono);font-size:.58rem;letter-spacing:.12em;text-transform:uppercase;
  padding:3px 9px;border-radius:6px;color:#fff;background:var(--accent);flex:0 0 auto}
:root[data-theme="dark"] .course .subj{color:#0E1116}
@media (prefers-color-scheme:dark){.course .subj{color:#0E1116}}
.course h3{margin:0;font-size:1.06rem;font-weight:640;letter-spacing:-.015em;color:var(--ink);line-height:1.25}
a.course:hover h3{color:var(--accent-ink)}
.course .arw{margin-left:auto;color:var(--muted);transition:transform .2s,color .2s;flex:0 0 auto}
a.course:hover .arw{transform:translate(2px,-2px);color:var(--accent-ink)}
.course p{margin:0;color:var(--muted);font-size:.9rem;line-height:1.5}
.course .cmeta{font-family:var(--sans);font-size:.74rem;font-weight:600;color:var(--muted);margin-top:2px}

/* ---------- COURSE INDEX (tutorials in portfolio theme) ---------- */
.course-meta{display:flex;flex-wrap:wrap;gap:14px;margin:16px 0 0;font-family:var(--sans);font-size:.82rem;color:var(--muted)}
.course-meta span{display:inline-flex;align-items:center;gap:7px}
.course-meta span::before{content:"";width:4px;height:4px;border-radius:50%;background:var(--accent);flex:0 0 auto}
.lessons{display:flex;flex-direction:column;gap:10px;margin-top:4px}
a.lesson{display:flex;align-items:center;gap:16px;background:var(--surface);border:1px solid var(--hair);
  border-radius:12px;padding:15px 18px;box-shadow:0 1px 2px rgba(20,23,28,.04);
  transition:transform .18s ease,border-color .2s ease,box-shadow .25s ease}
a.lesson:hover{transform:translateY(-2px);border-color:color-mix(in srgb,var(--accent) 42%,var(--hair));
  box-shadow:0 12px 26px -16px rgba(20,23,28,.28)}
:root[data-theme="dark"] a.lesson:hover{box-shadow:0 14px 30px -18px rgba(0,0,0,.7)}
.lesson .day{font-family:var(--mono);font-size:.58rem;letter-spacing:.06em;text-transform:uppercase;
  color:#fff;background:var(--accent);border-radius:7px;padding:7px 6px;min-width:50px;text-align:center;
  flex:0 0 auto;line-height:1.2}
:root[data-theme="dark"] .lesson .day{color:#0E1116}
@media (prefers-color-scheme:dark){.lesson .day{color:#0E1116}}
.lesson .lbody{min-width:0}
.lesson .lbody h3{margin:0 0 3px;font-size:1.04rem;font-weight:640;letter-spacing:-.01em;color:var(--ink);line-height:1.3}
a.lesson:hover .lbody h3{color:var(--accent-ink)}
.lesson .lbody p{margin:0;color:var(--muted);font-size:.9rem;line-height:1.5}
.lesson .arw{margin-left:auto;color:var(--muted);flex:0 0 auto;transition:transform .2s,color .2s}
.lesson .arw svg{width:18px;height:18px;display:block}
a.lesson:hover .arw{transform:translateX(3px);color:var(--accent-ink)}
.course-note{margin-top:34px;color:var(--muted);font-size:.9rem;font-style:italic;line-height:1.55}
/* simple, blog-like list of visual explanations (no course scaffolding) */
.tut-list{list-style:none;margin:6px 0 0;padding:0}
.tut-list li{border-bottom:1px solid var(--hair-2)}
.tut-list li:last-child{border-bottom:0}
.tut-list a{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:17px 2px;
  font-size:1.18rem;font-weight:600;letter-spacing:-.015em;color:var(--ink);line-height:1.3}
.tut-list a:hover{color:var(--accent-ink)}
.tut-list a .ar{flex:0 0 auto;color:var(--muted);transition:transform .2s ease,color .2s ease}
.tut-list a .ar svg{width:18px;height:18px;display:block}
.tut-list a:hover .ar{transform:translateX(3px);color:var(--accent-ink)}

footer.site{border-top:1px solid var(--hair);padding:26px 0;color:var(--muted);font-size:.82rem;font-family:var(--sans);
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px}

/* reveal */
.reveal{opacity:0;transform:translateY(12px);transition:opacity .6s ease,transform .6s cubic-bezier(.2,.7,.2,1)}
.reveal.in{opacity:1;transform:none}

/* ---------- BLOG INDEX PAGE ---------- */
.page-head{max-width:var(--readw);margin:0 auto;padding:clamp(40px,7vw,72px) clamp(20px,5vw,40px) 0}
.page-head .kicker{font-family:var(--mono);font-size:.66rem;letter-spacing:.14em;text-transform:uppercase;color:var(--accent-ink)}
.page-head h1{font-family:var(--sans);font-size:clamp(2rem,5vw,2.7rem);letter-spacing:-.025em;font-weight:720;margin:12px 0 8px;color:var(--ink)}
.page-head p{color:var(--muted);max-width:56ch;margin:0}
.blog-wrap{max-width:var(--readw);margin:0 auto;padding:28px clamp(20px,5vw,40px) 110px}
.filters{display:flex;flex-wrap:wrap;gap:8px;margin:26px 0 6px}
.filters button{font-family:var(--sans);font-size:.78rem;font-weight:600;color:var(--muted);background:transparent;
  border:1px solid var(--hair);border-radius:100px;padding:5px 13px;cursor:pointer;transition:.18s}
.filters button:hover{color:var(--ink);border-color:var(--accent)}
.filters button.on{color:#fff;background:var(--accent);border-color:var(--accent)}
:root[data-theme="dark"] .filters button.on{color:#0E1116}
@media (prefers-color-scheme:dark){.filters button.on{color:#0E1116}}

/* ---------- ARTICLE / POST ---------- */
.progress{position:fixed;top:0;left:0;height:2.5px;background:var(--accent);width:0;z-index:60}
article{max-width:var(--readw);margin:0 auto;padding:48px clamp(20px,5vw,40px) 40px;font-size:18px;line-height:1.7}
.eyebrow{display:flex;align-items:center;gap:12px;font-family:var(--sans);margin-bottom:20px;flex-wrap:wrap}
.eyebrow .cat{font-size:.72rem;font-weight:700;color:var(--accent-ink);background:var(--accent-soft);border-radius:100px;padding:4px 12px}
.eyebrow .meta{font-family:var(--mono);font-size:.68rem;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
h1.post{font-family:var(--sans);font-size:clamp(2rem,5vw,2.85rem);line-height:1.1;letter-spacing:-.025em;
  font-weight:720;margin:0 0 18px;text-wrap:balance;color:var(--ink)}
.post-rule{height:1px;background:var(--hair);margin:30px 0 36px}

.post-body p{margin:0 0 22px;color:var(--ink-2)}
.post-body h1{font-family:var(--sans);font-size:1.7rem;font-weight:700;letter-spacing:-.02em;margin:46px 0 14px;line-height:1.2;color:var(--ink)}
.post-body h2{font-family:var(--sans);font-size:1.5rem;font-weight:680;letter-spacing:-.02em;margin:44px 0 14px;line-height:1.2;color:var(--ink)}
.post-body h3{font-family:var(--sans);font-size:1.18rem;font-weight:660;letter-spacing:-.01em;margin:36px 0 12px;color:var(--ink)}
.post-body h4{font-family:var(--sans);font-size:1.02rem;font-weight:660;margin:28px 0 10px;color:var(--ink)}
.post-body ul,.post-body ol{margin:0 0 22px;padding-left:22px;color:var(--ink-2)}
.post-body li{margin:0 0 8px}
.post-body li>ul,.post-body li>ol{margin:8px 0 0}
.post-body img{max-width:100%;height:auto;display:block;margin:8px auto 10px;border-radius:12px;border:1px solid var(--hair)}
.post-body figure{margin:0 0 24px}
.post-body em{font-style:italic}
.post-body strong{color:var(--ink);font-weight:640}
.post-body a{color:var(--accent-ink);border-bottom:1px solid color-mix(in srgb,var(--accent) 35%,transparent)}
.post-body a:hover{border-bottom-color:var(--accent)}
.post-body blockquote{margin:0 0 22px;padding:2px 18px;border-left:3px solid var(--accent);
  background:var(--surface);border-radius:0 10px 10px 0;color:var(--ink-2)}
.post-body blockquote p:last-child{margin-bottom:0}
.post-body code{font-family:var(--mono);font-size:.86em;background:var(--code-bg);color:var(--code-ink);padding:2px 6px;border-radius:5px}
.post-body pre{background:var(--code-bg);border:1px solid var(--hair);border-radius:12px;padding:18px 20px;overflow-x:auto;margin:0 0 22px}
.post-body pre code{background:none;padding:0;font-size:.82rem;line-height:1.6;color:inherit}
.post-body hr{border:0;border-top:1px solid var(--hair);margin:34px 0}
.post-body table{width:100%;border-collapse:collapse;margin:0 0 22px;font-size:.92rem}
.post-body th,.post-body td{border:1px solid var(--hair);padding:8px 12px;text-align:left}
.katex-display{overflow-x:auto;overflow-y:hidden;padding:4px 0}

.post-foot{max-width:var(--readw);margin:0 auto;padding:0 clamp(20px,5vw,40px) 100px}
.post-foot .card{background:var(--surface);border:1px solid var(--hair);border-radius:14px;padding:20px 22px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.post-foot img{width:52px;height:52px;border-radius:11px;object-fit:cover;border:1px solid var(--hair)}
.post-foot .n{font-family:var(--sans)}
.post-foot .n b{font-weight:680;letter-spacing:-.01em;color:var(--ink)}
.post-foot .n span{color:var(--muted);font-size:.88rem}
.post-foot .to-all{margin-left:auto;font-family:var(--sans);font-size:.85rem;font-weight:600;color:var(--accent-ink)}

.backbar{position:sticky;top:0;z-index:40;background:color-mix(in srgb,var(--paper) 85%,transparent);
  backdrop-filter:saturate(1.2) blur(10px);-webkit-backdrop-filter:saturate(1.2) blur(10px);
  border-bottom:1px solid transparent;transition:border-color .3s}
.backbar.scrolled{border-color:var(--hair)}
.backbar-in{max-width:var(--readw);margin:0 auto;padding:0 clamp(20px,5vw,40px);height:56px;display:flex;align-items:center;justify-content:space-between;font-family:var(--sans)}
.back{display:inline-flex;align-items:center;gap:8px;color:var(--ink-2);font-size:.9rem;font-weight:600}
.back:hover{color:var(--accent-ink)}
.back svg{width:16px;height:16px}

.loading{max-width:var(--readw);margin:0 auto;padding:80px clamp(20px,5vw,40px);color:var(--muted);font-family:var(--sans);text-align:center}

@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important;scroll-behavior:auto!important}
  .reveal{opacity:1;transform:none}
}