/* ==========================================================================
   Shantanu Parmar — Academic site
   Design tokens
   ========================================================================== */
:root {
  /* Color */
  --ink:        #10192b;   /* primary dark ink — text, nav */
  --ink-soft:   #2c3a54;   /* secondary ink — subheads */
  --paper:      #f7f4ec;   /* warm parchment background */
  --paper-deep: #efe9d9;   /* recessed panel / card background */
  --paper-line: #d9d0b8;   /* hairline rule on paper */
  --brass:      #a8703a;   /* primary accent — links, active state */
  --brass-deep: #7f5326;   /* hover / pressed accent */
  --crimson:    #7c3230;   /* status: accepted / talk */
  --pine:       #3c5a44;   /* status: ongoing / oral */
  --slate:      #5c6270;   /* muted text */
  --white:      #fffdf8;

  /* Type */
  --font-display: 'Fraunces', 'Iowan Old Style', Georgia, serif;
  --font-body: 'Source Sans 3', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  /* Layout */
  --content-w: 980px;
  --wide-w: 1180px;
  --gutter: clamp(20px, 5vw, 56px);
}

/* ==========================================================================
   Reset
   ========================================================================== */
* { margin: 0; padding: 0; box-sizing: border-box; }

html {
  background: var(--paper);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

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

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

/* faint star-field texture, used sparingly behind hero sections */
.field-tex {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(1px 1px at 10% 20%, rgba(16,25,43,0.18) 0, transparent 60%),
    radial-gradient(1px 1px at 80% 10%, rgba(16,25,43,0.14) 0, transparent 60%),
    radial-gradient(1.5px 1.5px at 60% 65%, rgba(16,25,43,0.16) 0, transparent 60%),
    radial-gradient(1px 1px at 30% 80%, rgba(16,25,43,0.12) 0, transparent 60%),
    radial-gradient(1px 1px at 92% 55%, rgba(16,25,43,0.14) 0, transparent 60%),
    radial-gradient(1.5px 1.5px at 45% 35%, rgba(16,25,43,0.10) 0, transparent 60%);
  opacity: 0.9;
}

/* ==========================================================================
   Eyebrow / catalog-style labels — the page's recurring signature device.
   Modeled on astronomical object designations (e.g. "SP-01 · RESEARCH").
   ========================================================================== */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brass-deep);
}

.eyebrow::before {
  content: '';
  width: 22px;
  height: 1px;
  background: var(--brass-deep);
  display: inline-block;
}

/* ==========================================================================
   Header / Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 244, 236, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--paper-line);
}

.nav-wrap {
  max-width: var(--wide-w);
  margin: 0 auto;
  padding: 16px var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-decoration: none;
  color: var(--ink);
  display: flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
}

.brand .mark {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--brass);
  transform: translateY(-1px);
}

.brand small {
  font-size: 11px;
  color: var(--slate);
  font-weight: 400;
}

nav.primary-nav ul {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: wrap;
}

nav.primary-nav a {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink-soft);
  padding: 8px 12px;
  border-radius: 3px;
  transition: color 0.15s ease, background 0.15s ease;
}

nav.primary-nav a:hover { color: var(--brass-deep); background: var(--paper-deep); }

nav.primary-nav a.active {
  color: var(--ink);
  font-weight: 600;
  box-shadow: inset 0 -2px 0 var(--brass);
}

nav.primary-nav a.cv-link {
  border: 1px solid var(--ink);
  color: var(--ink);
  margin-left: 6px;
}
nav.primary-nav a.cv-link:hover { background: var(--ink); color: var(--white); }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--ink);
  width: 38px;
  height: 34px;
  border-radius: 3px;
  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: 1.5px;
  background: var(--ink);
  position: relative;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }

@media (max-width: 880px) {
  .nav-toggle { display: flex; }
  nav.primary-nav {
    display: none;
    width: 100%;
    order: 3;
  }
  nav.primary-nav.open { display: block; }
  nav.primary-nav ul { flex-direction: column; align-items: stretch; padding: 10px 0 4px; }
  nav.primary-nav a { padding: 10px 4px; }
  .nav-wrap { flex-wrap: wrap; }
}

/* ==========================================================================
   Page header (non-home pages)
   ========================================================================== */
.page-header {
  max-width: var(--wide-w);
  margin: 0 auto;
  padding: 64px var(--gutter) 40px;
  border-bottom: 1px solid var(--paper-line);
}

.page-header h1 {
  font-family: var(--font-display);
  font-size: clamp(34px, 5vw, 52px);
  font-weight: 600;
  margin-top: 14px;
  color: var(--ink);
}

.page-header .lede {
  font-size: 17px;
  color: var(--slate);
  max-width: 640px;
  margin-top: 14px;
}

/* ==========================================================================
   Hero (home page)
   ========================================================================== */
.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--paper-line);
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: var(--wide-w);
  margin: 0 auto;
  padding: 88px var(--gutter) 72px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 56px;
  align-items: center;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(40px, 6vw, 68px);
  line-height: 1.04;
  font-weight: 600;
  color: var(--ink);
  margin: 18px 0 20px;
}

.hero h1 em {
  font-style: italic;
  color: var(--brass-deep);
}

.hero .role {
  font-size: 18px;
  color: var(--ink-soft);
  max-width: 520px;
  margin-bottom: 26px;
}

.hero .coords {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--slate);
  border-top: 1px solid var(--paper-line);
  padding-top: 16px;
  margin-top: 30px;
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-portrait {
  position: relative;
  justify-self: center;
}

.hero-portrait .frame {
  width: 100%;
  max-width: 320px;
  aspect-ratio: 4/5;
  overflow: hidden;
  border: 1px solid var(--ink);
  background: var(--paper-deep);
  box-shadow: 10px 10px 0 var(--paper-line);
}

.hero-portrait img { width: 100%; height: 100%; object-fit: cover; }

.hero-portrait .tag {
  position: absolute;
  bottom: -14px;
  left: -14px;
  background: var(--ink);
  color: var(--white);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  padding: 6px 10px;
}

@media (max-width: 780px) {
  .hero-inner { grid-template-columns: 1fr; padding-top: 56px; }
  .hero-portrait { order: -1; max-width: 220px; margin: 0 auto; }
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-decoration: none;
  padding: 11px 18px;
  border: 1px solid var(--ink);
  color: var(--ink);
  transition: all 0.15s ease;
  background: transparent;
}
.btn:hover { background: var(--ink); color: var(--white); }

.btn.primary { background: var(--ink); color: var(--white); }
.btn.primary:hover { background: var(--brass-deep); border-color: var(--brass-deep); }

.btn.small { padding: 7px 12px; font-size: 11.5px; }

/* ==========================================================================
   Sections / generic content blocks
   ========================================================================== */
.section {
  max-width: var(--wide-w);
  margin: 0 auto;
  padding: 56px var(--gutter);
  border-bottom: 1px solid var(--paper-line);
}

.section:last-of-type { border-bottom: none; }

.section-head {
  margin-bottom: 34px;
  max-width: 640px;
}

.section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.4vw, 36px);
  font-weight: 600;
  margin-top: 10px;
}

.section-head p { color: var(--slate); margin-top: 10px; font-size: 15px; }

/* ==========================================================================
   Home — highlight strip
   ========================================================================== */
.stat-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--ink);
}

.stat-strip div {
  padding: 22px 20px;
  border-right: 1px solid var(--paper-line);
}
.stat-strip div:last-child { border-right: none; }

.stat-strip .num {
  font-family: var(--font-display);
  font-size: 30px;
  color: var(--ink);
}
.stat-strip .label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--slate);
  margin-top: 6px;
}

@media (max-width: 700px) {
  .stat-strip { grid-template-columns: 1fr 1fr; }
  .stat-strip div:nth-child(2) { border-right: none; }
  .stat-strip div:nth-child(1), .stat-strip div:nth-child(2) { border-bottom: 1px solid var(--paper-line); }
}

/* ==========================================================================
   Home — focus areas
   ========================================================================== */
.focus-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--paper-line);
  border: 1px solid var(--paper-line);
}

.focus-card {
  background: var(--paper);
  padding: 28px 24px;
}

.focus-card .idx {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--brass-deep);
}

.focus-card h3 {
  font-family: var(--font-display);
  font-size: 20px;
  margin: 10px 0 8px;
}

.focus-card p { font-size: 14.5px; color: var(--slate); }

@media (max-width: 780px) {
  .focus-grid { grid-template-columns: 1fr; }
}

/* ==========================================================================
   About page
   ========================================================================== */
.about-layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 48px;
}

.about-layout .portrait {
  border: 1px solid var(--ink);
  overflow: hidden;
  aspect-ratio: 4/5;
}
.about-layout .portrait img { width: 100%; height: 100%; object-fit: cover; }

.about-copy p { margin-bottom: 16px; font-size: 15.5px; }
.about-copy p:last-child { margin-bottom: 0; }

@media (max-width: 720px) {
  .about-layout { grid-template-columns: 1fr; }
  .about-layout .portrait { max-width: 240px; margin: 0 auto; }
}

/* Education timeline */
.timeline { border-top: 1px solid var(--ink); }

.timeline-item {
  border-bottom: 1px solid var(--paper-line);
}

.timeline-head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 20px 4px;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-body);
}

.timeline-head .inst {
  display: flex;
  align-items: center;
  gap: 16px;
}

.timeline-head img {
  width: 52px;
  height: 52px;
  object-fit: contain;
  background: var(--white);
  border: 1px solid var(--paper-line);
  padding: 4px;
  flex-shrink: 0;
}

.timeline-head h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
}

.timeline-head .yrs {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--slate);
  white-space: nowrap;
}

.timeline-head .chev {
  font-family: var(--font-mono);
  color: var(--brass-deep);
  transition: transform 0.2s ease;
  flex-shrink: 0;
}

.timeline-item.open .chev { transform: rotate(45deg); }

.timeline-body {
  display: none;
  padding: 0 4px 26px 68px;
}
.timeline-item.open .timeline-body { display: block; }

.timeline-body li {
  font-size: 14px;
  color: var(--ink-soft);
  padding: 6px 0;
  border-bottom: 1px dotted var(--paper-line);
}
.timeline-body li:last-child { border-bottom: none; }
.timeline-body a { color: var(--brass-deep); }

/* Associations */
.assoc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.assoc-card {
  border: 1px solid var(--paper-line);
  background: var(--paper-deep);
  padding: 20px;
  text-align: center;
}

.assoc-card img { height: 56px; margin: 0 auto 14px; object-fit: contain; }
.assoc-card p { font-size: 13px; color: var(--ink-soft); }
.assoc-card b { color: var(--ink); }

/* ==========================================================================
   Research
   ========================================================================== */
.domain-label {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink);
  border-bottom: 2px solid var(--ink);
  padding-bottom: 10px;
  margin: 48px 0 28px;
}
.domain-label:first-child { margin-top: 0; }

.research-card {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 30px;
  padding: 30px 0;
  border-bottom: 1px solid var(--paper-line);
}
.research-card:last-child { border-bottom: none; }

.research-card .media {
  width: 100%;
  aspect-ratio: 16/10;
  overflow: hidden;
  border: 1px solid var(--ink);
  background: #000;
}
.research-card .media img, .research-card .media video { width: 100%; height: 100%; object-fit: cover; }

.research-card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 8px;
}

.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 10px; }

.tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.03em;
  padding: 4px 9px;
  border: 1px solid currentColor;
}
.tag.venue { color: var(--brass-deep); }
.tag.accepted { color: var(--pine); }
.tag.talk { color: var(--crimson); }
.tag.status { color: var(--slate); }

.research-card .meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--slate);
  font-style: normal;
  margin-bottom: 12px;
}

.research-card p.abstract { font-size: 14.5px; color: var(--ink-soft); margin-bottom: 14px; }

.link-row { display: flex; flex-wrap: wrap; gap: 10px; }
.link-row a {
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  text-decoration: none;
  padding: 7px 12px;
  border: 1px solid var(--ink);
  color: var(--ink);
}
.link-row a:hover { background: var(--ink); color: var(--white); }

@media (max-width: 720px) {
  .research-card { grid-template-columns: 1fr; }
}

/* ==========================================================================
   Projects
   ========================================================================== */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.project-card {
  border: 1px solid var(--paper-line);
  background: var(--white);
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}
.project-card:hover { box-shadow: 6px 6px 0 var(--paper-line); transform: translate(-2px, -2px); }

.project-card .thumb {
  aspect-ratio: 16/10;
  overflow: hidden;
  border-bottom: 1px solid var(--paper-line);
  background: var(--paper-deep);
}
.project-card .thumb img { width: 100%; height: 100%; object-fit: cover; }

.project-card .body { padding: 18px; }
.project-card h3 {
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 600;
  margin-bottom: 12px;
  min-height: 44px;
}

.project-card .links { display: flex; gap: 14px; flex-wrap: wrap; }
.project-card .links a {
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  color: var(--brass-deep);
  text-decoration: none;
}
.project-card .links a:hover { text-decoration: underline; }

/* ==========================================================================
   Outreach
   ========================================================================== */
.outreach-group h3 {
  font-family: var(--font-display);
  font-size: 20px;
  margin: 40px 0 16px;
}
.outreach-group:first-child h3 { margin-top: 0; }

.talk-list li {
  border-bottom: 1px solid var(--paper-line);
  padding: 14px 0;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
}
.talk-list li:last-child { border-bottom: none; }

.talk-list .title { font-size: 14.5px; color: var(--ink-soft); flex: 1; min-width: 220px; }

.talk-list a.watch {
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--brass-deep);
  border-bottom: 1px solid var(--brass-deep);
  white-space: nowrap;
}
.talk-list a.watch:hover { color: var(--brass); }

/* ==========================================================================
   Contact
   ========================================================================== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1px;
  background: var(--paper-line);
  border: 1px solid var(--paper-line);
}

.contact-card {
  background: var(--paper);
  padding: 26px 22px;
}

.contact-card h3 {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--brass-deep);
  margin-bottom: 10px;
}

.contact-card a, .contact-card span { font-size: 14.5px; color: var(--ink-soft); text-decoration: none; }
.contact-card a:hover { color: var(--brass-deep); text-decoration: underline; }

.contact-card ul.icons { display: flex; gap: 16px; }
.contact-card ul.icons a { font-size: 20px; color: var(--ink); }
.contact-card ul.icons a:hover { color: var(--brass-deep); }

/* Beyond research / hobbies strip */
.photo-strip {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 6px;
}
.photo-strip img {
  width: 150px;
  height: 190px;
  object-fit: cover;
  border: 1px solid var(--ink);
  flex-shrink: 0;
}

/* ==========================================================================
   Footer
   ========================================================================== */
footer.site-footer {
  border-top: 1px solid var(--paper-line);
  padding: 30px var(--gutter) 40px;
}

.footer-inner {
  max-width: var(--wide-w);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-inner .copy {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--slate);
}

.footer-inner ul.icons { display: flex; gap: 16px; }
.footer-inner ul.icons a { color: var(--ink-soft); font-size: 16px; }
.footer-inner ul.icons a:hover { color: var(--brass-deep); }

/* ==========================================================================
   Utility
   ========================================================================== */
.reduced-motion, .no-motion * { transition: none !important; animation: none !important; }

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