/* ==========================================================================
   Ankit Mathanker — Academic portfolio
   Palette: dark navy base, teal / purple / blue accents, glass cards
   ========================================================================== */

:root {
  --bg-deep: #060d1a;
  --bg-elevated: rgba(15, 28, 48, 0.65);
  --accent-teal: #2dd4bf;
  --accent-blue: #38bdf8;
  --accent-purple: #a78bfa;
  --accent-magenta: #c084fc;
  --text-primary: #e8edf5;
  --text-muted: #94a3b8;
  --border-glass: rgba(148, 163, 184, 0.12);
  --glow-teal: rgba(45, 212, 191, 0.35);
  --glow-purple: rgba(167, 139, 250, 0.3);
  --radius-md: 0.65rem;
  --radius-lg: 1rem;
  --radius-full: 9999px;
  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --header-h: 4rem;
  --transition: 0.22s ease;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-deep);
  overflow-x: hidden;
}

/* --- Particle canvas (fixed behind content) --- */
.particle-canvas {
  position: fixed;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.55;
}

/* --- Skip link --- */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 1000;
  padding: 0.75rem 1rem;
  background: var(--accent-teal);
  color: var(--bg-deep);
  font-weight: 600;
  border-radius: 0.5rem;
  text-decoration: none;
  transition: top var(--transition);
}

.skip-link:focus {
  top: 1rem;
  outline: 2px solid var(--accent-purple);
  outline-offset: 2px;
}

/* --- Sticky nav with blur --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: rgba(6, 13, 26, 0.72);
  border-bottom: 1px solid var(--border-glass);
}

.nav {
  max-width: 72rem;
  margin: 0 auto;
  padding: 0 1.25rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: 0.06em;
  text-decoration: none;
  background: linear-gradient(120deg, var(--accent-teal), var(--accent-blue), var(--accent-purple));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  border: 1px solid var(--border-glass);
  padding: 0.4rem 0.65rem;
  border-radius: 0.5rem;
  transition: box-shadow var(--transition), border-color var(--transition);
}

.nav__logo:hover,
.nav__logo:focus-visible {
  box-shadow: 0 0 20px var(--glow-teal);
  border-color: rgba(45, 212, 191, 0.35);
  outline: none;
}

.nav__menu {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
  align-items: center;
}

.nav__menu a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
  padding: 0.35rem 0;
  position: relative;
  transition: color var(--transition);
}

.nav__menu a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-teal), var(--accent-purple));
  transition: width var(--transition);
}

.nav__menu a:hover,
.nav__menu a:focus-visible {
  color: var(--text-primary);
  outline: none;
}

.nav__menu a:hover::after,
.nav__menu a:focus-visible::after {
  width: 100%;
}

/* Mobile hamburger */
.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0;
  border: 1px solid var(--border-glass);
  border-radius: 0.5rem;
  background: var(--bg-elevated);
  cursor: pointer;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.nav__toggle:hover,
.nav__toggle:focus-visible {
  border-color: rgba(45, 212, 191, 0.4);
  box-shadow: 0 0 16px var(--glow-teal);
  outline: none;
}

.nav__toggle-bar {
  display: block;
  width: 1.25rem;
  height: 2px;
  margin: 0 auto;
  background: var(--text-primary);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav.is-open .nav__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav.is-open .nav__toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav.is-open .nav__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 768px) {
  .nav__toggle {
    display: flex;
  }

  .nav__menu {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 1rem 1.25rem 1.5rem;
    background: rgba(6, 13, 26, 0.95);
    border-bottom: 1px solid var(--border-glass);
    backdrop-filter: blur(12px);
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
  }

  .nav.is-open .nav__menu {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav__menu li {
    border-bottom: 1px solid var(--border-glass);
  }

  .nav__menu a {
    display: block;
    padding: 0.85rem 0;
  }

  .nav__menu a::after {
    display: none;
  }
}

/* Offset in-page anchors for sticky header */
section[id] {
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

/* --- Layout --- */
main,
.site-footer {
  position: relative;
  z-index: 1;
}

.section {
  max-width: 72rem;
  margin: 0 auto;
  padding: 4rem 1.25rem;
}

.section__head {
  margin-bottom: 2.5rem;
  text-align: center;
}

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.section__lead {
  margin: 0;
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 36rem;
  margin-inline: auto;
}

.gradient-text {
  background: linear-gradient(120deg, var(--accent-teal), var(--accent-blue) 45%, var(--accent-purple));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* --- Glass cards --- */
.glass-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.glass-card:hover {
  transform: translateY(-2px);
  border-color: rgba(148, 163, 184, 0.22);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.45), 0 0 24px rgba(45, 212, 191, 0.08);
}

/* --- Hero --- */
.hero {
  padding-top: calc(var(--header-h) + 2rem);
  padding-bottom: 4rem;
  min-height: min(92vh, 900px);
  display: flex;
  align-items: center;
}

.hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  align-items: center;
  width: 100%;
}

@media (min-width: 900px) {
  .hero__grid {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 2.5rem;
  }
}

.hero__eyebrow {
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent-teal);
  margin: 0 0 0.75rem;
  font-weight: 600;
}

.hero__name {
  font-size: clamp(2.5rem, 6vw, 3.75rem);
  font-weight: 700;
  line-height: 1.1;
  margin: 0 0 0.75rem;
  letter-spacing: -0.03em;
}

.hero__subtitle {
  font-size: 1.25rem;
  color: var(--text-primary);
  margin: 0 0 0.35rem;
  font-weight: 500;
}

.hero__affil {
  margin: 0 0 1.75rem;
  color: var(--text-muted);
  font-size: 1rem;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.35rem;
  font-size: 0.9375rem;
  font-weight: 600;
  font-family: inherit;
  border-radius: 0.65rem;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background var(--transition);
}

.btn--primary {
  background: linear-gradient(135deg, var(--accent-teal), #0d9488);
  color: #041016;
  box-shadow: 0 4px 20px rgba(45, 212, 191, 0.35);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 8px 28px rgba(45, 212, 191, 0.45);
  outline: none;
}

.btn--ghost {
  background: rgba(15, 28, 48, 0.5);
  color: var(--text-primary);
  border-color: var(--border-glass);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: rgba(167, 139, 250, 0.45);
  box-shadow: 0 0 20px var(--glow-purple);
  outline: none;
}

.hero__visual {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
}

.hero__photo-wrap {
  position: relative;
  width: min(280px, 75vw);
  height: min(280px, 75vw);
}

.hero__photo-ring {
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  background: conic-gradient(from 180deg, var(--accent-teal), var(--accent-blue), var(--accent-purple), var(--accent-teal));
  animation: ring-pulse 3.5s ease-in-out infinite;
}

@keyframes ring-pulse {
  0%,
  100% {
    opacity: 0.85;
    transform: scale(1);
    filter: blur(0);
  }
  50% {
    opacity: 1;
    transform: scale(1.03);
    filter: blur(0.5px);
  }
}

.hero__photo {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
  border: 3px solid rgba(6, 13, 26, 0.9);
  background: linear-gradient(145deg, #0f2847, #1a1033);
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.5);
}

.photo-toggle {
  position: relative;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1rem;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  background: var(--bg-elevated);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.photo-toggle:hover,
.photo-toggle:focus-visible {
  border-color: rgba(56, 189, 248, 0.45);
  box-shadow: 0 0 18px rgba(56, 189, 248, 0.2);
  outline: none;
}

.photo-toggle__icon {
  font-size: 1.1rem;
  line-height: 1;
}

/* --- About --- */
.section--about {
  padding-top: 2rem;
}

.about__grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1fr;
}

@media (min-width: 960px) {
  .about__grid {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: start;
  }
}

.about__bio {
  padding: 1.75rem;
}

.about__bio p {
  margin: 0 0 1rem;
  color: var(--text-muted);
}

.about__bio p:last-child {
  margin-bottom: 0;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 1rem;
}

.stat-card {
  padding: 1.25rem;
  text-align: center;
}

.stat-card__value {
  display: block;
  font-size: 1.75rem;
  font-weight: 700;
  background: linear-gradient(120deg, var(--accent-teal), var(--accent-purple));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.stat-card__label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.education-card {
  padding: 1.5rem;
}

.education-card__title {
  margin: 0 0 1rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.timeline li {
  padding-left: 1rem;
  border-left: 2px solid rgba(45, 212, 191, 0.35);
}

.timeline__degree {
  display: block;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.95rem;
}

.timeline__meta {
  display: block;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* --- Research grid --- */
.research-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}

@media (min-width: 600px) {
  .research-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .research-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.research-card {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.research-card__icon {
  font-size: 1.75rem;
  line-height: 1;
}

.research-card__title {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.research-card__desc {
  margin: 0;
  flex: 1;
  font-size: 0.9375rem;
  color: var(--text-muted);
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.tag-row--wrap {
  margin-top: 0.25rem;
}

.tag {
  display: inline-block;
  padding: 0.25rem 0.55rem;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent-blue);
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: var(--radius-full);
}

/* --- Showcase --- */
.showcase {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 0;
  max-width: none;
}

.showcase__media {
  position: relative;
  width: 100%;
  min-height: min(56vw, 520px);
  max-height: 640px;
  overflow: hidden;
}

.showcase__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  min-height: 320px;
  background: linear-gradient(160deg, #0c1829, #1e1b4b);
}

.showcase__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(6, 13, 26, 0.95) 0%, rgba(6, 13, 26, 0.2) 55%, transparent 100%);
  pointer-events: none;
}

.showcase__caption-wrap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 2rem 1.25rem 2.5rem;
  max-width: 72rem;
  margin: 0 auto;
}

.showcase__title {
  margin: 0 0 0.5rem;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.showcase__caption {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-muted);
  max-width: 48rem;
  line-height: 1.55;
}

/* --- Publications --- */
.pub-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  counter-reset: pub;
}

.pub-item {
  display: grid;
  grid-template-columns: auto minmax(0, 11rem) minmax(0, 1fr);
  gap: 1rem 1.25rem;
  padding: 1.25rem 1.5rem;
  align-items: start;
}

.pub-item__figure {
  margin: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-glass);
  background: rgba(15, 23, 42, 0.45);
  align-self: start;
}

.pub-item__thumb-link {
  display: block;
  line-height: 0;
  outline: none;
  transition: box-shadow var(--transition), transform var(--transition);
}

.pub-item__thumb-link:hover .pub-item__thumb,
.pub-item__thumb-link:focus-visible .pub-item__thumb {
  transform: scale(1.02);
}

.pub-item__thumb-link:focus-visible {
  box-shadow: 0 0 0 2px var(--bg-deep), 0 0 0 4px rgba(45, 212, 191, 0.55);
  border-radius: var(--radius-md);
}

.pub-item__thumb {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  vertical-align: middle;
  transition: transform var(--transition);
}

.pub-item__num {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent-teal);
  opacity: 0.9;
  min-width: 2rem;
  line-height: 1.3;
}

.pub-item__title {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
}

.pub-item__title a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid rgba(148, 163, 184, 0.35);
  transition: color var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.pub-item__title a:hover,
.pub-item__title a:focus-visible {
  color: var(--accent-teal);
  border-bottom-color: rgba(45, 212, 191, 0.55);
  outline: none;
}

.pub-item__meta {
  margin: 0 0 0.35rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.pub-item__authors {
  margin: 0 0 0.65rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border-radius: var(--radius-full);
}

@media (max-width: 768px) {
  .pub-item {
    grid-template-columns: auto 1fr;
  }

  .pub-item__figure {
    grid-column: 1 / -1;
    grid-row: 1;
    width: 100%;
    max-width: none;
  }

  .pub-item__num {
    grid-column: 1;
    grid-row: 2;
    align-self: start;
  }

  .pub-item__body {
    grid-column: 2;
    grid-row: 2;
    min-width: 0;
  }
}

.badge--press {
  color: #fbbf24;
  background: rgba(251, 191, 36, 0.12);
  border: 1px solid rgba(251, 191, 36, 0.35);
}

.badge--review {
  color: var(--accent-blue);
  background: rgba(56, 189, 248, 0.12);
  border: 1px solid rgba(56, 189, 248, 0.35);
}

.badge--published {
  color: var(--accent-teal);
  background: rgba(45, 212, 191, 0.12);
  border: 1px solid rgba(45, 212, 191, 0.35);
}

/* --- Skills --- */
.skills-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.skill-card {
  padding: 1.5rem;
}

.skill-card__title {
  margin: 0 0 1rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* --- Awards --- */
.awards-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}

@media (min-width: 600px) {
  .awards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .awards-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.award-card {
  padding: 1.35rem;
}

.award-card__icon {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.award-card__title {
  margin: 0 0 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.35;
}

.award-card__desc {
  margin: 0;
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* --- Contact --- */
.section--contact {
  padding-bottom: 5rem;
}

.contact {
  max-width: 36rem;
  margin: 0 auto;
  padding: 2.5rem 2rem;
  text-align: center;
}

.contact .section__title {
  margin-bottom: 0.5rem;
}

.contact__lead {
  margin: 0 0 1.5rem;
  color: var(--text-muted);
}

.contact__email {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--accent-teal);
  text-decoration: none;
  margin-bottom: 0.75rem;
  transition: color var(--transition), text-shadow var(--transition);
}

.contact__email:hover,
.contact__email:focus-visible {
  color: var(--accent-blue);
  text-shadow: 0 0 20px var(--glow-teal);
  outline: none;
}

.contact__email-icon {
  font-size: 1.25rem;
}

.contact__cv {
  margin: 0 0 1.75rem;
}

.contact__cv-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}

.contact__cv-link:hover,
.contact__cv-link:focus-visible {
  color: var(--accent-purple);
  border-bottom-color: rgba(167, 139, 250, 0.5);
  outline: none;
}

.contact__cv-icon {
  font-size: 1.1rem;
}

.contact__socials {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
}

.social-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  border: 1px solid var(--border-glass);
  border-radius: 0.65rem;
  background: rgba(15, 28, 48, 0.4);
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.social-btn:hover,
.social-btn:focus-visible {
  border-color: rgba(167, 139, 250, 0.45);
  box-shadow: 0 0 20px var(--glow-purple);
  transform: translateY(-2px);
  outline: none;
}

.social-btn__icon {
  width: 1.125rem;
  height: 1.125rem;
}

/* --- Footer --- */
.site-footer {
  padding: 1.5rem 1.25rem 2rem;
  text-align: center;
  border-top: 1px solid var(--border-glass);
  color: var(--text-muted);
  font-size: 0.875rem;
}

.site-footer p {
  margin: 0;
}