/* ============================================================
   kirankumar.ai — design tokens
   bg: graphite (not pure black) · amber = signal/decision accent
   blue = data/flow accent · Fraunces (display) + IBM Plex Mono
   (structural/technical) + IBM Plex Sans (body)
   ============================================================ */

:root {
  --bg: #0d1015;
  --bg-elevated: #151a21;
  --bg-elevated-2: #1b212a;
  --text: #ece8e0;
  --text-dim: #8b93a1;
  --text-faint: #565f6c;
  --accent: #e8a33d;
  --accent-soft: rgba(232, 163, 61, 0.14);
  --accent-2: #6f9bf0;
  --accent-2-soft: rgba(111, 155, 240, 0.14);
  --rule: rgba(236, 232, 224, 0.1);
  --rule-strong: rgba(236, 232, 224, 0.18);
  --font-display: 'Fraunces', 'Iowan Old Style', Georgia, serif;
  --font-mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;
  --font-body: 'IBM Plex Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --max-width: 1080px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s ease-in-out;
}
a:hover, a:focus { color: #f4c169; }

:focus-visible {
  outline: 2px solid var(--accent-2);
  outline-offset: 3px;
}

.wrap {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 28px;
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: -0.01em;
  margin: 0;
  color: var(--text);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.eyebrow::before {
  content: "";
  display: inline-block;
  width: 18px;
  height: 1px;
  background: var(--accent);
}

/* ---------- nav ---------- */

#mainNav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  font-family: var(--font-mono);
  background: rgba(13, 16, 21, 0.82);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}

#mainNav.navbar-shrink {
  border-bottom: 1px solid var(--rule);
}

#mainNav .nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 18px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

#mainNav .navbar-brand {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
}
#mainNav .navbar-brand:hover { color: var(--accent); }
#mainNav .navbar-brand .dot { color: var(--accent); }

#mainNav .navbar-toggler {
  font-size: 13px;
  padding: 8px 12px;
  color: var(--text);
  border: 1px solid var(--rule-strong);
  background: transparent;
  border-radius: 2px;
}

#mainNav .navbar-nav {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}

#mainNav .nav-item { list-style: none; }

#mainNav .nav-link {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
}
#mainNav .nav-link:hover { color: var(--text); }
#mainNav .nav-link.cv { color: var(--accent); }

@media (max-width: 1179px) {
  #mainNav .navbar-toggler {
    display: inline-block;
    position: relative;
    width: 34px;
    height: 34px;
    padding: 0;
  }

  #mainNav .navbar-toggler .bar {
    position: absolute;
    left: 8px;
    right: 8px;
    height: 1.5px;
    background: var(--text);
    transition: transform 0.3s ease, opacity 0.2s ease, top 0.3s ease;
  }
  #mainNav .navbar-toggler .bar:nth-child(1) { top: 11px; }
  #mainNav .navbar-toggler .bar:nth-child(2) { top: 16.5px; }
  #mainNav .navbar-toggler .bar:nth-child(3) { top: 22px; }

  #mainNav .navbar-toggler[aria-expanded="true"] .bar:nth-child(1) {
    top: 16.5px;
    transform: rotate(45deg);
  }
  #mainNav .navbar-toggler[aria-expanded="true"] .bar:nth-child(2) {
    opacity: 0;
  }
  #mainNav .navbar-toggler[aria-expanded="true"] .bar:nth-child(3) {
    top: 16.5px;
    transform: rotate(-45deg);
  }

  #mainNav .navbar-collapse {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: 0;
    overflow: hidden;
    background: var(--bg);
    border-bottom: 1px solid transparent;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.4s ease;
  }

  #mainNav .navbar-collapse.show {
    max-height: min(70vh, 520px);
    overflow-y: auto;
    border-bottom-color: var(--rule);
  }

  #mainNav .navbar-nav {
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity 0.3s ease, transform 0.3s ease;
  }

  #mainNav .navbar-collapse.show .navbar-nav {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.1s;
  }
}

/* Laptop / narrow-desktop: horizontal reveal bar — a second thin
   bar spans full width with links in a single dividered row, same
   voice as the full desktop nav rather than a stacked mobile list. */
@media (min-width: 700px) and (max-width: 1179px) {
  #mainNav .navbar-nav {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0;
    padding: 14px 28px;
  }

  #mainNav .nav-link {
    display: inline-block;
    padding: 8px 22px;
    border-right: 1px solid var(--rule);
  }
  #mainNav .nav-item:last-child .nav-link { border-right: none; }
}

/* Phone: full-width vertical drawer, better suited to touch. */
@media (max-width: 699px) {
  #mainNav .navbar-nav {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    padding: 12px 28px 24px;
  }

  #mainNav .nav-link {
    display: block;
    padding: 10px 0;
    width: 100%;
    border-bottom: 1px solid var(--rule);
    font-size: 13.5px;
  }
  #mainNav .nav-item:last-child .nav-link { border-bottom: none; }
}

@media (min-width: 1180px) {
  #mainNav .navbar-toggler {
    display: none;
  }

  #mainNav .navbar-collapse {
    display: block;
    position: static;
    background: transparent;
    border-bottom: none;
  }

  #mainNav .navbar-nav {
    overflow: visible;
    opacity: 1;
    transform: none;
  }
}

/* ---------- hero ---------- */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 140px 0 80px;
  overflow: hidden;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 420px);
  gap: 40px;
  align-items: center;
}

.hero-copy { max-width: 620px; }

.hero-headline {
  font-size: clamp(38px, 5.2vw, 64px);
  line-height: 1.08;
  margin-bottom: 24px;
}

.hero-headline em {
  font-style: italic;
  color: var(--accent);
}

.hero-sub {
  font-size: 18px;
  line-height: 1.65;
  color: var(--text-dim);
  margin: 0 0 36px;
  max-width: 56ch;
}

.hero-sub strong { color: var(--text); font-weight: 500; }

.hero-cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 13px 22px;
  border-radius: 2px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.15s ease-in-out;
}

.btn-primary {
  background: var(--accent);
  color: #14110a;
  font-weight: 600;
}
.btn-primary:hover { background: #f4c169; color: #14110a; }

.btn-ghost {
  border: 1px solid var(--rule-strong);
  color: var(--text);
}
.btn-ghost:hover { border-color: var(--accent-2); color: var(--accent-2); }

.hero-graphic {
  width: 100%;
  height: 380px;
}
.hero-graphic svg { width: 100%; height: 100%; }

.route-line {
  fill: none;
  stroke-width: 1.4;
  stroke-linecap: round;
  stroke-dasharray: 460;
  stroke-dashoffset: 460;
  animation: draw 1.8s ease forwards;
}
.route-line.dim { stroke: var(--rule-strong); }
.route-line.blue { stroke: var(--accent-2); }
.route-line.amber { stroke: var(--accent); }
.route-node { fill: var(--bg); stroke: var(--text-faint); stroke-width: 1.2; }
.route-node.active { stroke: var(--accent); fill: var(--accent-soft); }
.route-node.dest { stroke: var(--accent-2); fill: var(--accent-2-soft); }

@keyframes draw {
  to { stroke-dashoffset: 0; }
}

@media (max-width: 860px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-graphic { height: 220px; opacity: 0.6; }
}

/* ---------- sections ---------- */

section {
  padding: 110px 0;
  border-top: 1px solid var(--rule);
}

.section-head {
  max-width: 640px;
  margin-bottom: 56px;
}

.section-head h2 {
  font-size: clamp(26px, 3vw, 36px);
  line-height: 1.25;
}

/* ---------- building / projects ---------- */

.project-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.project-card {
  background: var(--bg);
  padding: 36px;
}

.project-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.project-head h3 {
  font-size: 21px;
  font-family: var(--font-mono);
  font-weight: 600;
  letter-spacing: -0.01em;
}
.project-head h3 a { color: var(--text); }
.project-head h3 a:hover { color: var(--accent); }

.project-lang {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-faint);
  border: 1px solid var(--rule-strong);
  padding: 3px 8px;
  border-radius: 2px;
  white-space: nowrap;
}

.project-card p {
  color: var(--text-dim);
  line-height: 1.65;
  font-size: 15.5px;
  margin: 0 0 20px;
}

.project-meta {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-faint);
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.project-meta li::before { content: "· "; color: var(--accent); }

.project-link {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
}

.more-link {
  margin-top: 28px;
  font-family: var(--font-mono);
  font-size: 13px;
}

@media (max-width: 860px) {
  .project-grid { grid-template-columns: 1fr; }
}

/* ---------- experience timeline ---------- */

.timeline {
  border-top: 1px solid var(--rule);
}

.tl-item {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 24px;
  padding: 26px 0;
  border-bottom: 1px solid var(--rule);
}

.tl-date {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-faint);
  padding-top: 4px;
}

.tl-body h3 {
  font-family: var(--font-body);
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 6px;
}
.tl-body h3 .co { color: var(--text-dim); font-weight: 400; }

.tl-body p {
  color: var(--text-dim);
  font-size: 15px;
  line-height: 1.6;
  margin: 0;
  max-width: 62ch;
}

@media (max-width: 640px) {
  .tl-item { grid-template-columns: 1fr; gap: 6px; }
}

.cv-note {
  margin-top: 36px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-faint);
}

/* ---------- research ---------- */

.research-list {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
}

.research-list li {
  padding: 18px 0;
  border-bottom: 1px solid var(--rule);
}

.research-list .r-title { color: var(--text); font-size: 16.5px; }
.research-list .r-meta {
  display: block;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-faint);
  margin-top: 6px;
}

/* ---------- contact ---------- */

#contact { text-align: center; }
#contact .section-head { margin: 0 auto 40px; }
#contact .section-head p {
  color: var(--text-dim);
  font-size: 16px;
  margin-top: 14px;
}

.social-row {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}

.social-row a {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: 1px solid var(--rule-strong);
  color: var(--text);
  padding: 12px 20px;
  border-radius: 2px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.social-row a:hover { border-color: var(--accent); color: var(--accent); }

footer {
  padding: 40px 0;
  border-top: 1px solid var(--rule);
  text-align: center;
}
footer p {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-faint);
  margin: 0;
}