/* ==========================================================================
   Dr. Rakesh Kumar — Portfolio
   Design language: cyanotype blueprint meets structural drafting.
   Palette, type and layout tokens below.
   ========================================================================== */

:root{
  --ink:        #14181c;   /* structural steel — near-black */
  --paper:      #eceee9;   /* concrete grey-white */
  --paper-2:    #e2e5df;   /* slightly deeper panel tone */
  --blueprint:  #1b4b66;   /* cyanotype blue — primary accent */
  --blueprint-2:#4a90a4;   /* lighter blueprint blue */
  --signal:     #b8842a;   /* rebar / brass amber — secondary accent */
  --line:       #b9bdb4;   /* hairline grey */
  --line-strong:#8b9088;
  --white:      #fbfbf9;

  --font-display: 'Space Grotesk', sans-serif;
  --font-body:    'IBM Plex Serif', serif;
  --font-mono:    'IBM Plex Mono', monospace;

  --max: 1180px;
  --gutter: clamp(20px, 5vw, 64px);
}

*,*::before,*::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
body{
  margin:0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img{ max-width:100%; display:block; }
a{ color: inherit; }

::selection{ background: var(--blueprint); color: var(--white); }

/* Focus visibility */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible{
  outline: 2px solid var(--signal);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce){
  *{ animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

/* ---------- Page backdrop (plain, no pattern) ---------- */
.grid-bg{
  position: relative;
  background-color: var(--paper);
}

/* ---------- Layout shell ---------- */
.wrap{ max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }

/* ---------- Header / nav ---------- */
.site-header{
  position: sticky; top:0; z-index: 50;
  background: rgba(236,238,233,0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line-strong);
}
.site-header .wrap{
  display:flex; align-items:center; justify-content:space-between;
  height: 76px;
}
.brand{
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
  text-decoration:none;
  display:flex; align-items:center; gap:10px;
}
.brand .mark{
  width: 30px; height:30px;
  border: 1.5px solid var(--ink);
  display:flex; align-items:center; justify-content:center;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--blueprint);
  background: var(--white);
  transform: rotate(0deg);
}
.brand small{
  display:block; font-family: var(--font-mono); font-weight:400; font-size:0.62rem;
  letter-spacing: 0.12em; color: var(--blueprint); text-transform: uppercase; margin-top:2px;
}

nav.primary-nav{ display:flex; align-items:center; gap: 2px; }
nav.primary-nav a{
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration:none;
  color: var(--ink);
  padding: 8px 14px;
  position: relative;
}
nav.primary-nav a::after{
  content:"";
  position:absolute; left:14px; right:14px; bottom:4px; height:1px;
  background: var(--signal);
  transform: scaleX(0); transform-origin:left;
  transition: transform .25s ease;
}
nav.primary-nav a:hover::after, nav.primary-nav a[aria-current="page"]::after{ transform: scaleX(1); }
nav.primary-nav a[aria-current="page"]{ color: var(--blueprint); }

.nav-toggle{
  display:none; background:none; border:1px solid var(--ink); width:40px; height:40px;
  cursor:pointer; align-items:center; justify-content:center;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after{
  content:""; display:block; width:18px; height:2px; background:var(--ink); position:relative;
}
.nav-toggle span::before{ position:absolute; top:-6px; }
.nav-toggle span::after{ position:absolute; top:6px; }

@media (max-width: 820px){
  nav.primary-nav{
    position:fixed; inset: 76px 0 0 0; height:calc(100dvh - 76px);
    background: var(--paper); flex-direction:column; align-items:flex-start;
    padding: 24px var(--gutter); gap: 4px;
    transform: translateX(100%); transition: transform .3s ease;
    border-top: 1px solid var(--line-strong);
  }
  nav.primary-nav.open{ transform: translateX(0); }
  nav.primary-nav a{ width:100%; padding: 16px 4px; font-size: 0.95rem; border-bottom:1px solid var(--line); }
  .nav-toggle{ display:flex; }
}

/* ---------- Eyebrow / drafting labels ---------- */
.eyebrow{
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blueprint);
  display:flex; align-items:center; gap:10px;
  margin: 0 0 14px;
}
.eyebrow::before{ content:""; width:22px; height:1px; background: var(--signal); display:inline-block; }

/* ---------- Section frame (annotated / cropmark box) ---------- */
.frame{
  position:relative;
  border: 1px solid var(--line-strong);
  padding: clamp(20px,4vw,40px);
  background: var(--white);
}
.frame::before, .frame::after,
.frame .tick-br, .frame .tick-bl{
  content:""; position:absolute; width:10px; height:10px; border-color: var(--blueprint); border-style:solid; border-width:0;
}
.frame::before{ top:-1px; left:-1px; border-top-width:2px; border-left-width:2px; }
.frame::after{ top:-1px; right:-1px; border-top-width:2px; border-right-width:2px; }
.frame .tick-bl{ bottom:-1px; left:-1px; border-bottom-width:2px; border-left-width:2px; }
.frame .tick-br{ bottom:-1px; right:-1px; border-bottom-width:2px; border-right-width:2px; }

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:10px;
  font-family: var(--font-mono); font-size:0.78rem; letter-spacing:0.06em; text-transform:uppercase;
  text-decoration:none; padding: 13px 22px; border: 1px solid var(--ink); color: var(--ink);
  background: transparent; cursor:pointer; transition: background .2s ease, color .2s ease, border-color .2s ease;
}
.btn:hover{ background: var(--ink); color: var(--white); }
.btn.primary{ background: var(--blueprint); border-color: var(--blueprint); color: var(--white); }
.btn.primary:hover{ background: var(--ink); border-color: var(--ink); }
.btn svg{ width:14px; height:14px; }

/* ---------- Headings ---------- */
h1,h2,h3,h4{ font-family: var(--font-display); font-weight:700; margin: 0 0 0.5em; line-height:1.1; }
.h-huge{ font-size: clamp(2.4rem, 6vw, 4.6rem); letter-spacing:-0.01em; }
.h-section{ font-size: clamp(1.6rem, 3.4vw, 2.3rem); }
p{ margin: 0 0 1em; color: #2a2f33; }
.lede{ font-size: 1.15rem; color: var(--ink); }

/* ---------- Page hero banner (interior pages) ---------- */
.page-hero{
  padding: 64px 0 40px;
  border-bottom: 1px solid var(--line-strong);
}
.page-hero .kicker{ font-family: var(--font-mono); color: var(--blueprint); font-size:0.78rem; letter-spacing:0.14em; text-transform:uppercase; }

/* ---------- Section spacing ---------- */
section{ padding: clamp(48px, 8vw, 96px) 0; }
section.tight{ padding: clamp(32px,5vw,56px) 0; }
.divider{ border:none; border-top:1px solid var(--line-strong); margin:0; }

/* ---------- Hero (home) ---------- */
.hero{
  padding: 56px 0 64px;
  position: relative;
}
.hero-grid{
  display:grid; grid-template-columns: 1.05fr 0.95fr; gap: clamp(24px,4vw,56px);
  align-items:center;
}
@media (max-width: 900px){ .hero-grid{ grid-template-columns: 1fr; } }

.hero-copy .role{
  font-family: var(--font-mono); font-size:0.95rem; color: var(--blueprint-2);
  margin-bottom: 18px; letter-spacing:0.02em;
}
.hero-copy .name{ font-size: clamp(2.6rem, 6.4vw, 4.4rem); }
.hero-copy .tagline{ max-width: 46ch; }

.stat-strip{
  display:flex; flex-wrap:wrap; gap: 0;
  margin-top: 30px;
  border-top: 1px solid var(--line-strong);
}
.stat{
  flex:1 1 120px; padding: 16px 18px 4px 0; border-right: 1px solid var(--line-strong);
}
.stat:last-child{ border-right:none; }
.stat .n{ font-family: var(--font-mono); font-size:1.6rem; color: var(--blueprint); display:block; }
.stat .l{ font-family: var(--font-mono); font-size:0.68rem; letter-spacing:0.08em; text-transform:uppercase; color:#5a6058; }

.hero-actions{ display:flex; gap:14px; flex-wrap:wrap; margin-top: 30px; }

/* ---------- Slideshow ---------- */
.slideshow{
  position:relative;
  height: 420px;
  height: clamp(380px, 56vw, 620px);
  overflow:hidden;
  border: 1px solid var(--ink);
  background: var(--ink);
}
@media (min-width: 901px){ .slideshow{ height: 480px; height: clamp(420px, 34vw, 560px); } }
.slideshow::before{
  content: "FIG. 01 — FIELD RECORD";
  position:absolute; top:10px; left:10px; z-index:5;
  font-family: var(--font-mono); font-size:0.62rem; letter-spacing:0.1em; text-transform:uppercase;
  color: var(--white); background: rgba(20,24,28,0.55); padding: 5px 9px;
}
.slide{
  position:absolute; inset:0; opacity:0; transition: opacity 1.1s ease;
}
.slide.active{ opacity:1; }
.slide img{
  width:100%; height:100%; object-fit:contain; object-position: center center;
  background: var(--ink);
  transform: scale(1.06);
  transition: transform 7s linear;
}
.slide.active img{ transform: scale(1); }
.slide .cap{
  position:absolute; left:0; right:0; bottom:0;
  padding: 14px 16px 12px;
  background: linear-gradient(0deg, rgba(20,24,28,0.86), rgba(20,24,28,0));
  color: var(--white);
  font-family: var(--font-mono); font-size:0.72rem; letter-spacing:0.03em;
}
.slide-dots{
  position:absolute; right:12px; bottom:14px; z-index:6;
  display:flex; gap:6px;
}
.slide-dots button{
  width:7px; height:7px; border-radius:50%; border:1px solid var(--white);
  background: transparent; padding:0; cursor:pointer;
}
.slide-dots button.active{ background: var(--white); }

/* ---------- Load-path diagram (signature element) ---------- */
.load-path{
  margin-top: 10px;
}
.load-path svg{ width:100%; height:auto; display:block; }
.load-path text{ font-family: var(--font-mono); }

/* ---------- Cards ---------- */
.grid-3{ display:grid; grid-template-columns: repeat(3,1fr); gap: 1px; background: var(--line-strong); border:1px solid var(--line-strong); }
.grid-2{ display:grid; grid-template-columns: repeat(2,1fr); gap: 1px; background: var(--line-strong); border:1px solid var(--line-strong); }
@media (max-width: 760px){ .grid-3{ grid-template-columns: 1fr; } .grid-2{ grid-template-columns:1fr; } }

.card{ background: var(--white); padding: 28px 26px; transition: transform .35s cubic-bezier(.2,.8,.2,1), box-shadow .35s ease; }
.card .idx{ font-family: var(--font-mono); color: var(--signal); font-size:0.78rem; letter-spacing:0.08em; }
.card h3{ font-size: 1.15rem; margin-top:8px; }
.card p{ font-size:0.96rem; }
.grid-3 .card:hover, .grid-2 .card:hover{
  transform: translateY(-6px);
  box-shadow: 0 18px 34px -18px rgba(20,24,28,0.35);
  position: relative; z-index: 2;
}

/* ---------- Publication list ---------- */
.pub{
  display:grid; grid-template-columns: 84px 1fr; gap: 22px;
  padding: 26px 0; border-bottom: 1px solid var(--line);
}
.pub:first-child{ padding-top:0; }
.pub .yr{ font-family: var(--font-mono); color: var(--blueprint); font-size:0.95rem; padding-top:2px; }
.pub h3{ font-size: 1.08rem; margin-bottom:6px; }
.pub .venue{ font-family: var(--font-mono); font-size:0.78rem; color:#565c54; letter-spacing:0.02em; text-transform:uppercase; }
.pub .desc{ margin-top:8px; font-size:0.95rem; }
.pub .tags{ margin-top:10px; display:flex; gap:8px; flex-wrap:wrap; }
.tag{
  font-family: var(--font-mono); font-size:0.66rem; letter-spacing:0.06em; text-transform:uppercase;
  border:1px solid var(--line-strong); padding:3px 8px; color:#4b504a;
}

/* ---------- Timeline (experience) ---------- */
.timeline{ position:relative; padding-left: 32px; }
.timeline::before{ content:""; position:absolute; left:6px; top:6px; bottom:6px; width:1px; background: var(--line-strong); }
.tl-item{ position:relative; padding-bottom: 42px; }
.tl-item:last-child{ padding-bottom:0; }
.tl-item::before{
  content:""; position:absolute; left:-32px; top:4px; width:11px; height:11px;
  background: var(--paper); border:2px solid var(--blueprint);
}
.tl-item .period{ font-family: var(--font-mono); font-size:0.76rem; color: var(--blueprint); text-transform:uppercase; letter-spacing:0.06em; }
.tl-item h3{ font-size:1.2rem; margin: 6px 0 2px; }
.tl-item .org{ font-family: var(--font-mono); font-size:0.86rem; color:#565c54; margin-bottom:10px; display:block; }

/* ---------- Skills ---------- */
.skill-row{
  display:grid; grid-template-columns: 220px 1fr; gap: 24px; align-items:start;
  padding: 22px 0; border-bottom: 1px solid var(--line);
}
@media (max-width:700px){ .skill-row{ grid-template-columns: 1fr; gap:10px; } }
.skill-row .cat{ font-family: var(--font-display); font-weight:700; font-size:1.02rem; }
.skill-row .cat small{ display:block; font-family:var(--font-mono); font-weight:400; font-size:0.68rem; color:var(--blueprint); letter-spacing:0.1em; text-transform:uppercase; margin-top:4px;}
.chip-row{ display:flex; flex-wrap:wrap; gap:9px; }
.chip{
  font-family: var(--font-mono); font-size:0.78rem;
  border:1px solid var(--ink); padding:7px 12px;
  background: var(--white);
}

/* meter bars (skills proficiency, qualitative) */
.meter{ margin-bottom:14px; }
.meter:last-child{ margin-bottom:0; }
.meter .row{ display:flex; justify-content:space-between; font-family:var(--font-mono); font-size:0.76rem; margin-bottom:6px; }
.meter .track{ height:6px; background: var(--paper-2); border:1px solid var(--line-strong); }
.meter .fill{ height:100%; background: var(--blueprint); }

/* ---------- Contact ---------- */
.contact-grid{ display:grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--line-strong); border:1px solid var(--line-strong); }
@media (max-width: 760px){ .contact-grid{ grid-template-columns: 1fr; } }
.contact-card{ background: var(--white); padding: 30px 28px; }
.contact-card .label{ font-family: var(--font-mono); font-size:0.72rem; letter-spacing:0.1em; text-transform:uppercase; color: var(--blueprint); }
.contact-card a.value, .contact-card .value{
  display:block; margin-top:10px; font-family: var(--font-display); font-weight:700; font-size:1.15rem; text-decoration:none;
  word-break: break-word;
}
.contact-card a.value:hover{ color: var(--blueprint); }

/* ---------- Footer ---------- */
footer.site-footer{
  border-top: 1px solid var(--line-strong);
  padding: 40px 0;
  margin-top: 20px;
}
footer .wrap{ display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:16px; }
footer .fmono{ font-family: var(--font-mono); font-size:0.74rem; color:#5a6058; letter-spacing:0.03em; }
footer .socials{ display:flex; gap:16px; }
footer .socials a{ font-family: var(--font-mono); font-size:0.74rem; text-decoration:none; border-bottom:1px solid var(--line-strong); padding-bottom:2px; margin-right:16px; }
footer .socials a:last-child{ margin-right:0; }
footer .socials a:hover{ border-color: var(--signal); color: var(--signal); }

/* ---------- Two column content (about) ---------- */
.split{ display:grid; grid-template-columns: 0.85fr 1.15fr; gap: clamp(28px,5vw,64px); align-items:start; }
@media (max-width: 860px){ .split{ grid-template-columns: 1fr; } }
.portrait-frame{ border: 1px solid var(--ink); padding:10px; background:var(--white); }
.portrait-frame img{ height: 420px; width:100%; object-fit:contain; object-position: center center; background: var(--paper-2); }
.portrait-frame .tag-line{ display:flex; justify-content:space-between; font-family:var(--font-mono); font-size:0.64rem; text-transform:uppercase; letter-spacing:0.06em; color:#5a6058; padding-top:8px; }

/* ---------- Scroll reveal ---------- */
.reveal-init{ opacity:0; transform: translateY(22px); }
.reveal-in{
  opacity:1; transform: translateY(0);
  transition: opacity .7s cubic-bezier(.2,.7,.2,1), transform .7s cubic-bezier(.2,.7,.2,1);
}

/* ---------- Header shrink on scroll ---------- */
.site-header{ transition: height .25s ease, box-shadow .25s ease; }
.site-header.scrolled{ box-shadow: 0 2px 14px -6px rgba(20,24,28,0.18); }
.site-header.scrolled .wrap{ height: 62px; transition: height .25s ease; }

/* ---------- Publication filter tabs ---------- */
.pub-filters{ display:flex; flex-wrap:wrap; gap:10px; margin: 22px 0 8px; }
.pub-filter{
  font-family: var(--font-mono); font-size:0.74rem; letter-spacing:0.05em; text-transform:uppercase;
  border:1px solid var(--line-strong); background:transparent; color:#4b504a;
  padding:8px 14px; cursor:pointer; transition: all .2s ease;
}
.pub-filter:hover{ border-color: var(--ink); color: var(--ink); }
.pub-filter.active{ background: var(--blueprint); border-color: var(--blueprint); color: var(--white); }
.pub.pub-hidden{ display:none; }

/* ---------- Animated meter fill ---------- */
.meter .fill{ height:100%; background: var(--blueprint); width:0; transition: width 1.4s cubic-bezier(.2,.8,.2,1); }
.meter.filled .fill{ width: var(--target-width, 0%); }

/* ---------- Number ticking ---------- */
.stat .n{ font-variant-numeric: tabular-nums; }

@media (prefers-reduced-motion: reduce){
  .reveal-init{ opacity:1; transform:none; }
  .slide img{ transform:none !important; transition:none !important; }
  .meter .fill{ transition:none; }
}
.mt-0{ margin-top:0; }
.text-mono{ font-family: var(--font-mono); }
.small{ font-size: 0.88rem; }
.center{ text-align:center; }