/* Yuganshu Kathuria — design system.  Palette: white / dark navy / slate / muted blue. */
:root{
  --paper:#ffffff; --surface:#f6f7f9; --surface-2:#eef1f5;
  --ink:#0b1f3a; --body:#3e4a5b; --muted:#697488;
  --accent:#3d6fa6; --accent-strong:#2f5c8a;
  --border:#e7eaef; --border-strong:#d8dde5;
  --shadow:0 1px 2px rgba(11,31,58,.05),0 8px 30px rgba(11,31,58,.05);
  --sans:'Inter',system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  --wrap:1120px; --prose:44rem; --radius:16px;
  --step:clamp(4.5rem,9vw,8rem);
}
html[data-theme="dark"]{
  --paper:#0a0f1a; --surface:#0f1726; --surface-2:#131d2f;
  --ink:#eef2f7; --body:#c3cdda; --muted:#8b95a7;
  --accent:#7ba3d7; --accent-strong:#9dbde6;
  --border:#1d2a3d; --border-strong:#26374e;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 34px rgba(0,0,0,.34);
}
*,*::before,*::after{box-sizing:border-box}
*{margin:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:6rem}
body{
  font-family:var(--sans);background:var(--paper);color:var(--body);
  line-height:1.65;font-size:1.0625rem;font-weight:400;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
  font-feature-settings:"cv05","ss01";
  transition:background .3s ease,color .3s ease;
}
::selection{background:rgba(61,111,166,.18)}
img,svg{display:block;max-width:100%}
a{color:var(--accent);text-decoration:none}
h1,h2,h3,h4{color:var(--ink);font-weight:600;letter-spacing:-.02em;line-height:1.1}
p{color:var(--body)}
strong{color:var(--ink);font-weight:600}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:4px}

.skip-link{position:absolute;left:-999px;top:0;background:var(--ink);color:#fff;
  padding:.6rem 1rem;border-radius:0 0 8px 0;z-index:200}
.skip-link:focus{left:0}

.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:clamp(1.25rem,4vw,2.5rem)}
.prose{max-width:var(--prose)}
.eyebrow{font-size:.75rem;font-weight:600;letter-spacing:.16em;text-transform:uppercase;
  color:var(--accent);margin-bottom:1.1rem;display:block}
.muted{color:var(--muted)}
.lead{font-size:clamp(1.15rem,1.7vw,1.4rem);line-height:1.55;color:var(--body);font-weight:400;
  max-width:42rem}
.rule{height:1px;background:var(--border);border:0;margin:0}
.center{text-align:center}

/* ---------- header ---------- */
.site-header{position:sticky;top:0;z-index:100;background:var(--paper);
  border-bottom:1px solid transparent;transition:border-color .3s,box-shadow .3s,background .3s}
.site-header.is-scrolled{border-bottom-color:var(--border);box-shadow:0 1px 0 rgba(11,31,58,.02)}
.nav{display:flex;align-items:center;gap:1.5rem;height:4.5rem}
.brand{font-weight:600;color:var(--ink);letter-spacing:-.01em;font-size:1.02rem;white-space:nowrap;
  display:flex;align-items:center;gap:.6rem}
.brand .mono{width:1.9rem;height:1.9rem;border-radius:7px;background:var(--ink);color:#fff;
  display:grid;place-items:center;font-size:.72rem;font-weight:700;letter-spacing:-.02em}
html[data-theme="dark"] .brand .mono{background:var(--surface-2);border:1px solid var(--border-strong)}
.nav-links{display:flex;align-items:center;gap:.35rem;margin-left:auto}
.nav-links a{color:var(--body);font-size:.94rem;padding:.5rem .7rem;border-radius:8px;
  transition:color .18s,background .18s}
.nav-links a:hover{color:var(--ink);background:var(--surface)}
.nav-links a[aria-current="page"]{color:var(--ink);font-weight:500}
.nav-actions{display:flex;align-items:center;gap:.4rem;margin-left:.4rem}
.icon-btn{width:2.3rem;height:2.3rem;display:grid;place-items:center;border-radius:9px;
  border:1px solid var(--border);background:transparent;color:var(--body);cursor:pointer;transition:.18s}
.icon-btn:hover{color:var(--ink);border-color:var(--border-strong);background:var(--surface)}
.nav-toggle{display:none}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:.5rem;font-family:inherit;font-size:.95rem;
  font-weight:500;padding:.72rem 1.3rem;border-radius:10px;cursor:pointer;border:1px solid transparent;
  transition:transform .15s,background .18s,border-color .18s,color .18s;white-space:nowrap}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--ink);color:#fff}
.btn-primary:hover{background:#12294a}
html[data-theme="dark"] .btn-primary{background:var(--accent);color:#06101f}
html[data-theme="dark"] .btn-primary:hover{background:var(--accent-strong)}
.btn-ghost{background:transparent;color:var(--ink);border-color:var(--border-strong)}
.btn-ghost:hover{border-color:var(--ink);background:var(--surface)}
.btn-arrow{color:var(--accent);font-weight:500;padding:0;background:none;border:0}
.btn-arrow .a{transition:transform .18s}
.btn-arrow:hover .a{transform:translateX(4px)}

/* ---------- sections & layout ---------- */
main{display:block}
.section{padding-block:var(--step)}
.section--tight{padding-block:clamp(3rem,6vw,4.5rem)}
.section-head{max-width:46rem;margin-bottom:clamp(2.2rem,4vw,3.2rem)}
.section-head h2{font-size:clamp(1.7rem,3.2vw,2.4rem)}
.section-head p{margin-top:1rem;font-size:1.12rem}
.grid{display:grid;gap:clamp(1.1rem,2vw,1.6rem)}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}

/* ---------- hero ---------- */
.hero{padding-top:clamp(3.5rem,7vw,6rem);padding-bottom:clamp(3rem,6vw,5rem)}
.hero h1{font-size:clamp(2.6rem,6vw,4.6rem);letter-spacing:-.035em;line-height:1.02;max-width:16ch}
.hero .lead{margin-top:1.6rem;font-size:clamp(1.15rem,1.7vw,1.4rem)}
.hero-cta{display:flex;flex-wrap:wrap;gap:.8rem;margin-top:2.3rem}
.hero-facts{display:flex;flex-wrap:wrap;gap:2.5rem;margin-top:3.4rem;padding-top:2.2rem;
  border-top:1px solid var(--border)}
.hero-fact .n{color:var(--ink);font-size:1.35rem;font-weight:600;letter-spacing:-.02em}
.hero-fact .l{color:var(--muted);font-size:.9rem;margin-top:.25rem}

/* page hero (interior) */
.page-hero{padding-top:clamp(3rem,6vw,5rem);padding-bottom:clamp(2rem,4vw,3rem)}
.page-hero h1{font-size:clamp(2.2rem,4.6vw,3.4rem);max-width:20ch}
.page-hero .lead{margin-top:1.4rem}

/* ---------- cards ---------- */
.card{background:var(--paper);border:1px solid var(--border);border-radius:var(--radius);
  padding:clamp(1.4rem,2.4vw,1.9rem);transition:border-color .2s,box-shadow .2s,transform .2s}
.card h3{font-size:1.18rem;margin-bottom:.55rem}
.card p{font-size:.98rem;color:var(--body)}
a.card:hover{border-color:var(--border-strong);box-shadow:var(--shadow);transform:translateY(-2px)}
.card--plain{background:var(--surface);border-color:transparent}

/* ---------- article cards ---------- */
.cover{position:relative;aspect-ratio:3/2;border-radius:12px;overflow:hidden;background:var(--surface-2)}
.cover .cover-art{width:100%;height:100%}
.article-card{display:flex;flex-direction:column;gap:1rem}
.article-card .cover{margin-bottom:.2rem}
.tag{display:inline-block;font-size:.72rem;font-weight:600;letter-spacing:.06em;text-transform:uppercase;
  color:var(--accent)}
.meta{font-size:.85rem;color:var(--muted);display:flex;gap:.6rem;align-items:center;flex-wrap:wrap}
.meta .dot{width:3px;height:3px;border-radius:50%;background:var(--muted);display:inline-block}
.article-card h3{font-size:1.24rem;line-height:1.25}
.article-card h3 a{color:var(--ink)}
.article-card:hover h3 a{color:var(--accent)}
.article-card p{font-size:.97rem;color:var(--body)}

/* list-of-links (index rows) */
.rows{border-top:1px solid var(--border)}
.row{display:grid;grid-template-columns:1fr auto;gap:1.5rem;padding:1.7rem 0;
  border-bottom:1px solid var(--border);align-items:start}
.row:hover .row-title{color:var(--accent)}
.row-title{font-size:1.3rem;font-weight:600;color:var(--ink);letter-spacing:-.02em}
.row p{margin-top:.5rem;font-size:1rem;max-width:52ch}
.row-side{text-align:right;color:var(--muted);font-size:.85rem;white-space:nowrap;padding-top:.35rem}

/* ---------- prose (article body & legal) ---------- */
.prose-body{max-width:var(--prose)}
.prose-body p{font-size:1.14rem;line-height:1.8;margin-top:1.5rem;color:var(--body)}
.prose-body p:first-child{margin-top:0}
.prose-body h2{font-size:1.5rem;margin-top:2.8rem;letter-spacing:-.02em}
.prose-link{color:var(--accent);text-decoration:underline;text-underline-offset:3px;
  text-decoration-thickness:1px;text-decoration-color:rgba(61,111,166,.4)}
.prose-link:hover{text-decoration-color:var(--accent)}
.legal h2{font-size:1.2rem;margin-top:2.4rem;margin-bottom:.6rem}
.legal p{margin-top:.4rem;line-height:1.75}
.legal .updated{color:var(--muted);font-size:.9rem}

/* ---------- feature lists ---------- */
.deflist{display:grid;gap:0}
.deflist .item{padding:1.6rem 0;border-top:1px solid var(--border);
  display:grid;grid-template-columns:15rem 1fr;gap:1.5rem}
.deflist .item:last-child{border-bottom:1px solid var(--border)}
.deflist h3{font-size:1.12rem;color:var(--ink)}
.deflist p{font-size:1rem;color:var(--body)}
.pill-list{display:flex;flex-wrap:wrap;gap:.6rem;margin-top:.4rem}
.pill{border:1px solid var(--border);border-radius:999px;padding:.5rem 1rem;font-size:.9rem;color:var(--body)}
.check-list{list-style:none;display:grid;gap:.9rem}
.check-list li{position:relative;padding-left:1.7rem;color:var(--body);line-height:1.6}
.check-list li::before{content:"";position:absolute;left:0;top:.55rem;width:.5rem;height:.5rem;
  border-radius:2px;background:var(--accent)}

/* ---------- book / cert rows ---------- */
.stack{display:grid;gap:0}
.stack .line{display:grid;grid-template-columns:auto 1fr;gap:1.1rem;padding:1.35rem 0;
  border-top:1px solid var(--border);align-items:baseline}
.stack .line:last-child{border-bottom:1px solid var(--border)}
.stack .k{color:var(--ink);font-weight:600;font-size:1.02rem}
.stack .sub{color:var(--muted);font-size:.9rem;margin-top:.15rem}
.stack .v{color:var(--body);font-size:.98rem}

/* ---------- callout / newsletter / cta ---------- */
.panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
  padding:clamp(1.8rem,4vw,3rem)}
.cta-band{background:var(--ink);border-radius:var(--radius);padding:clamp(2.2rem,5vw,3.6rem);color:#fff}
.cta-band h2{color:#fff;font-size:clamp(1.6rem,3vw,2.2rem);max-width:20ch}
.cta-band p{color:rgba(255,255,255,.72);margin-top:1rem;max-width:44ch}
.cta-band .btn-primary{background:#fff;color:var(--ink);margin-top:1.8rem}
.cta-band .btn-primary:hover{background:#eef1f5}
html[data-theme="dark"] .cta-band{background:var(--surface-2);border:1px solid var(--border-strong)}
html[data-theme="dark"] .cta-band h2{color:var(--ink)}
html[data-theme="dark"] .cta-band p{color:var(--muted)}
html[data-theme="dark"] .cta-band .btn-primary{background:var(--accent);color:#06101f}

/* ---------- forms ---------- */
.field{display:grid;gap:.45rem;margin-bottom:1.1rem}
.field label{font-size:.9rem;color:var(--ink);font-weight:500}
.input,textarea.input{width:100%;font-family:inherit;font-size:1rem;color:var(--ink);
  background:var(--paper);border:1px solid var(--border-strong);border-radius:10px;padding:.8rem .95rem;
  transition:border-color .18s,box-shadow .18s}
.input::placeholder{color:var(--muted)}
.input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(61,111,166,.15)}
textarea.input{min-height:8rem;resize:vertical}
.form-note{font-size:.85rem;color:var(--muted);margin-top:.4rem}
.form-success{display:none;background:var(--surface);border:1px solid var(--border);border-radius:12px;
  padding:1.1rem 1.2rem;color:var(--ink);font-size:.98rem;margin-top:.4rem}
.form-success.show{display:block}
.nl-form{display:flex;gap:.6rem;flex-wrap:wrap;margin-top:1.4rem}
.nl-form .input{flex:1;min-width:15rem}

/* ---------- search ---------- */
.search-input{font-size:1.15rem;padding:1rem 1.1rem}
.search-count{color:var(--muted);font-size:.9rem;margin:1.4rem 0}
.filterbar{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:1.4rem}
.chip{border:1px solid var(--border-strong);background:transparent;color:var(--body);border-radius:999px;
  padding:.45rem .95rem;font-size:.88rem;cursor:pointer;font-family:inherit;transition:.15s}
.chip:hover{border-color:var(--ink);color:var(--ink)}
.chip[aria-pressed="true"]{background:var(--ink);border-color:var(--ink);color:#fff}
html[data-theme="dark"] .chip[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:#06101f}

/* ---------- 404 ---------- */
.notfound{min-height:58vh;display:grid;align-content:center}
.notfound .code{font-size:clamp(3.5rem,10vw,6rem);color:var(--ink);letter-spacing:-.04em;font-weight:600}

/* ---------- footer ---------- */
.site-footer{border-top:1px solid var(--border);background:var(--surface);margin-top:var(--step)}
.footer-top{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:2rem;
  padding-block:clamp(3rem,5vw,4.5rem)}
.footer-brand .brand{font-size:1.05rem}
.footer-brand p{color:var(--muted);font-size:.92rem;margin-top:1rem;max-width:26rem}
.footer-col h4{font-size:.78rem;text-transform:uppercase;letter-spacing:.12em;color:var(--muted);
  font-weight:600;margin-bottom:1rem}
.footer-col a{display:block;color:var(--body);font-size:.94rem;padding:.32rem 0;transition:color .15s}
.footer-col a:hover{color:var(--ink)}
.footer-bottom{border-top:1px solid var(--border);padding-block:1.8rem;display:flex;
  justify-content:space-between;gap:1.5rem;flex-wrap:wrap;align-items:center}
.footer-bottom .disc{color:var(--muted);font-size:.82rem;max-width:48rem;line-height:1.6}
.footer-bottom .copy{color:var(--muted);font-size:.82rem;white-space:nowrap}

/* ---------- reveal ---------- */
.reveal{opacity:0;transform:translateY(14px);transition:opacity .6s cubic-bezier(.2,.6,.2,1),transform .6s cubic-bezier(.2,.6,.2,1)}
.reveal.is-visible{opacity:1;transform:none}

/* ---------- responsive ---------- */
@media (max-width:900px){
  .grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}
  .deflist .item{grid-template-columns:1fr;gap:.5rem}
  .footer-top{grid-template-columns:1fr 1fr;gap:1.8rem 2rem}
  .footer-brand{grid-column:1 / -1}
}
@media (max-width:640px){
  .nav-links{position:absolute;top:4.5rem;left:0;right:0;background:var(--paper);
    border-bottom:1px solid var(--border);flex-direction:column;align-items:stretch;gap:0;
    padding:.6rem clamp(1.25rem,4vw,2.5rem) 1rem;margin-left:0;display:none;box-shadow:var(--shadow)}
  .nav-links.open{display:flex}
  .nav-links a{padding:.75rem .4rem;border-radius:8px}
  .nav-toggle{display:grid;margin-left:auto}
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr}
  .row{grid-template-columns:1fr}
  .row-side{text-align:left;padding-top:0}
  .stack .line{grid-template-columns:1fr}
  .hero-facts{gap:1.5rem 2rem}
  .footer-top{grid-template-columns:1fr}
  .nl-form .input{min-width:100%}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms!important;transition-duration:.001ms!important}
  .reveal{opacity:1;transform:none}
}
@media print{.site-header,.site-footer,.nav-actions{display:none}}