/*
  Rohit Babbar academic website
  Static, responsive and compatible with GitHub Pages.
*/

:root {
  --background: #ffffff;
  --background-soft: #f4f6f8;
  --background-dark: #12263a;
  --text: #172033;
  --text-soft: #526173;
  --text-light: #eef4f8;
  --accent: #006f73;
  --accent-dark: #00595c;
  --accent-soft: #dff1f0;
  --border: #dfe5ea;
  --white: #ffffff;
  --shadow: 0 18px 50px rgba(23, 32, 51, 0.09);
  --radius: 18px;
  --page-width: 1120px;
  --header-height: 72px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 20px);
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family:
    Inter,
    ui-sans-serif,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--accent);
  text-underline-offset: 3px;
}

a:hover {
  color: var(--accent-dark);
}

button,
input {
  font: inherit;
}

h1,
h2,
h3 {
  margin-top: 0;
  color: var(--text);
  font-family:
    Georgia,
    "Times New Roman",
    serif;
  line-height: 1.15;
}

h1 {
  margin-bottom: 20px;
  font-size: clamp(2.35rem, 5vw, 4.25rem);
  letter-spacing: -0.035em;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(2rem, 4vw, 3.2rem);
  letter-spacing: -0.025em;
}

h3 {
  margin-bottom: 12px;
  font-size: 1.35rem;
}

p {
  margin-top: 0;
}

.page-width,
.nav-container {
  width: min(calc(100% - 40px), var(--page-width));
  margin-inline: auto;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 2000;
  padding: 10px 14px;
  background: var(--background-dark);
  color: var(--white);
  transform: translateY(-150%);
}

.skip-link:focus {
  transform: translateY(0);
}

/* Header and navigation */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  min-height: var(--header-height);
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid rgba(223, 229, 234, 0.9);
  backdrop-filter: blur(14px);
}

.nav-container {
  display: flex;
  min-height: var(--header-height);
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-name {
  color: var(--text);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.25rem;
  font-weight: 700;
  text-decoration: none;
}

.primary-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.primary-nav a {
  position: relative;
  color: var(--text-soft);
  font-size: 0.95rem;
  font-weight: 650;
  text-decoration: none;
}

.primary-nav a:hover,
.primary-nav a.active {
  color: var(--text);
}

.primary-nav a.active::after {
  position: absolute;
  right: 0;
  bottom: -23px;
  left: 0;
  height: 3px;
  background: var(--accent);
  content: "";
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 8px;
  background: transparent;
  border: 0;
  cursor: pointer;
}

.nav-toggle span:not(.sr-only) {
  display: block;
  width: 24px;
  height: 2px;
  margin: 5px auto;
  background: var(--text);
  transition: transform 180ms ease, opacity 180ms ease;
}

/* Hero */

.hero {
  overflow: hidden;
  padding: clamp(52px, 7vw, 88px) 0;
  background:
    radial-gradient(circle at 84% 28%, rgba(0, 111, 115, 0.13), transparent 28rem),
    linear-gradient(180deg, #ffffff 0%, #f9fbfc 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.65fr) minmax(230px, 0.55fr);
  align-items: center;
  gap: clamp(36px, 6vw, 72px);
}

.eyebrow {
  margin-bottom: 16px;
  color: var(--accent);
  font-size: 0.79rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.eyebrow-light {
  color: #8fe0dc;
}

.hero-lead {
  max-width: 760px;
  margin-bottom: 18px;
  color: var(--text);
  font-size: clamp(1.08rem, 1.8vw, 1.32rem);
  line-height: 1.55;
}

.hero-description {
  max-width: 700px;
  margin-bottom: 30px;
  color: var(--text-soft);
  font-size: 1.05rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 28px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 11px 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-weight: 750;
  text-decoration: none;
  transition: transform 150ms ease, background 150ms ease, border-color 150ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  background: var(--accent);
  color: var(--white);
}

.button-primary:hover {
  background: var(--accent-dark);
  color: var(--white);
}

.button-secondary {
  background: var(--white);
  color: var(--text);
  border-color: var(--border);
}

.button-secondary:hover {
  border-color: var(--accent);
  color: var(--accent-dark);
}

.profile-links {
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
}

.profile-links a {
  font-weight: 700;
  text-decoration: none;
}

.hero-photo-wrap {
  position: relative;
  width: min(100%, 290px);
  justify-self: end;
}

.hero-photo-wrap::before {
  position: absolute;
  top: 16px;
  right: -16px;
  bottom: -16px;
  left: 16px;
  z-index: 0;
  background: var(--accent-soft);
  border-radius: 22px;
  content: "";
}

.hero-photo {
  position: relative;
  z-index: 1;
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  object-position: center;
  border-radius: 22px;
  box-shadow: var(--shadow);
}

/* Sections */

.section {
  padding: clamp(72px, 9vw, 118px) 0;
}

.section-muted {
  background: var(--background-soft);
}

.section-dark {
  background: var(--background-dark);
  color: var(--text-light);
}

.section-dark h2,
.section-dark h3 {
  color: var(--white);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 46px;
}

.section-heading > p:last-child {
  margin-bottom: 0;
  color: var(--text-soft);
  font-size: 1.08rem;
}

.section-heading-row {
  display: flex;
  max-width: none;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
}

.text-link {
  flex-shrink: 0;
  margin-bottom: 20px;
  font-weight: 750;
  text-decoration: none;
}

.card-grid {
  display: grid;
  gap: 24px;
}

.research-grid {
  grid-template-columns: repeat(3, 1fr);
}

.card {
  padding: 32px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(23, 32, 51, 0.04);
}

.card-number {
  margin-bottom: 26px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 850;
  letter-spacing: 0.14em;
}

.card p {
  color: var(--text-soft);
}

.card .card-tags {
  margin: 26px 0 0;
  color: var(--accent-dark);
  font-size: 0.88rem;
  font-weight: 750;
}

/* Featured publications */

.featured-list {
  border-top: 1px solid var(--border);
}

.featured-item {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 36px;
  padding: 34px 0;
  border-bottom: 1px solid var(--border);
}

.featured-meta {
  display: flex;
  flex-direction: column;
  gap: 6px;
  color: var(--text-soft);
  font-size: 0.9rem;
}

.venue {
  color: var(--accent-dark);
  font-weight: 850;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.featured-item h3 {
  margin-bottom: 10px;
  font-size: 1.55rem;
}

.featured-item p {
  margin-bottom: 15px;
  color: var(--text-soft);
}

.publication-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.publication-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 5px 12px;
  background: var(--accent-soft);
  border-radius: 999px;
  color: var(--accent-dark);
  font-size: 0.85rem;
  font-weight: 800;
  text-decoration: none;
}

.publication-links a:hover {
  background: var(--accent);
  color: var(--white);
}

/* Group */

.group-layout {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: clamp(50px, 8vw, 110px);
}

.section-intro-light {
  max-width: 510px;
  color: #c6d2dc;
  font-size: 1.08rem;
}

.people-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
}

.people-list article {
  padding: 28px 24px 28px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
}

.people-list article:nth-child(even) {
  padding-left: 24px;
  border-left: 1px solid rgba(255, 255, 255, 0.16);
}

.people-list p {
  margin: 0;
  color: #c6d2dc;
}

/* Opportunity and teaching */

.opportunity-box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 56px;
  padding: 48px;
  background: linear-gradient(135deg, #ecf8f7 0%, #f7fbfb 100%);
  border: 1px solid #cde6e4;
  border-radius: 28px;
}

.opportunity-box > div {
  max-width: 760px;
}

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

.two-column {
  display: grid;
  grid-template-columns: 0.75fr 1.25fr;
  gap: 70px;
}

.clean-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.teaching-list {
  border-top: 1px solid var(--border);
}

.teaching-list li {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
}

.teaching-list li span:first-child {
  font-weight: 700;
}

.teaching-list li span:last-child {
  color: var(--text-soft);
  white-space: nowrap;
}

/* Publications page */

.page-hero {
  padding: clamp(70px, 9vw, 110px) 0 64px;
  background: linear-gradient(180deg, #ffffff 0%, #f6f9fa 100%);
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  margin-bottom: 20px;
  font-size: clamp(3rem, 7vw, 5.1rem);
}

.page-hero > .page-width > p:not(.eyebrow) {
  max-width: 760px;
  color: var(--text-soft);
  font-size: 1.15rem;
}

.publications-layout {
  display: grid;
  grid-template-columns: 245px minmax(0, 1fr);
  align-items: start;
  gap: 70px;
}

.publication-filter {
  position: sticky;
  top: calc(var(--header-height) + 28px);
  padding: 24px;
  background: var(--background-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.publication-filter h2 {
  margin-bottom: 20px;
  font-family: inherit;
  font-size: 1.05rem;
}

.publication-filter label {
  display: block;
  margin-bottom: 8px;
  color: var(--text-soft);
  font-size: 0.85rem;
  font-weight: 750;
}

.publication-filter input {
  width: 100%;
  min-height: 44px;
  padding: 8px 12px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  outline: none;
}

.publication-filter input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0, 111, 115, 0.13);
}

.filter-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.filter-button {
  padding: 6px 11px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-soft);
  cursor: pointer;
}

.filter-button:hover,
.filter-button.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--white);
}

.publication-count {
  margin-bottom: 16px;
  color: var(--text-soft);
  font-size: 0.9rem;
  font-weight: 700;
}

.publication-list {
  border-top: 1px solid var(--border);
}

.publication {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 24px;
  padding: 32px 0;
  border-bottom: 1px solid var(--border);
}

.publication[hidden] {
  display: none;
}

.publication-year {
  padding-top: 3px;
  color: var(--accent);
  font-size: 0.92rem;
  font-weight: 850;
}

.publication h2 {
  margin-bottom: 10px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.5rem;
  line-height: 1.3;
}

.authors,
.venue-line {
  margin-bottom: 8px;
  color: var(--text-soft);
}

.venue-line {
  font-style: italic;
}

.no-results {
  padding: 50px 0;
  color: var(--text-soft);
  text-align: center;
}

/* Footer */

.site-footer {
  padding: 70px 0 26px;
  background: #0d1d2c;
  color: #c8d3dc;
}

.site-footer h2,
.site-footer h3 {
  color: var(--white);
}

.site-footer h2 {
  font-size: 1.6rem;
}

.site-footer h3 {
  margin-bottom: 12px;
  font-family: inherit;
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 0.7fr;
  gap: 70px;
}

.footer-links {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-links li + li {
  margin-top: 8px;
}

.site-footer a {
  color: #e7f3f3;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-top: 46px;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  font-size: 0.85rem;
}

.footer-bottom p {
  margin: 0;
}

/* Responsive layout */

@media (max-width: 920px) {
  .nav-toggle {
    display: block;
  }

  .primary-nav {
    position: absolute;
    top: var(--header-height);
    right: 0;
    left: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px 20px 20px;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 20px 30px rgba(23, 32, 51, 0.08);
  }

  .primary-nav.open {
    display: flex;
  }

  .primary-nav a {
    padding: 12px 0;
  }

  .primary-nav a.active::after {
    display: none;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(2) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(3) {
    opacity: 0;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(4) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .hero-grid {
    grid-template-columns: 1fr;
  }

  .hero-photo-wrap {
    width: min(64%, 300px);
    justify-self: start;
  }

  .research-grid {
    grid-template-columns: 1fr;
  }

  .group-layout,
  .two-column,
  .publications-layout {
    grid-template-columns: 1fr;
  }

  .publication-filter {
    position: static;
  }

  .opportunity-box {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 700px) {
  body {
    font-size: 16px;
  }

  .page-width,
  .nav-container {
    width: min(calc(100% - 28px), var(--page-width));
  }

  .hero {
    padding-top: 58px;
  }

  .hero-photo-wrap {
    width: min(72%, 280px);
  }

  .section-heading-row {
    align-items: flex-start;
    flex-direction: column;
    gap: 0;
  }

  .text-link {
    margin-bottom: 0;
  }

  .featured-item {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .featured-meta {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .people-list {
    grid-template-columns: 1fr;
  }

  .people-list article,
  .people-list article:nth-child(even) {
    padding: 22px 0;
    border-right: 0;
    border-left: 0;
  }

  .opportunity-box {
    padding: 30px 24px;
  }

  .teaching-list li {
    align-items: flex-start;
    flex-direction: column;
    gap: 4px;
  }

  .publication {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
    gap: 6px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}