:root {
  --primary: #111827;
  --accent: #8b0000;
  --light-gray: #f3f4f6;
  --text: #1f2937;
  --muted: #6b7280;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  color: var(--text);
  line-height: 1.75;
  background: white;
}

header {
  border-bottom: 1px solid #e5e7eb;
  padding: 1rem 2rem;
}

.header-container {
  max-width: 1300px;
  margin: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo-area img {
  height: 90px;
}

nav {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

nav a {
  text-decoration: none;
  color: var(--muted);
  font-weight: 500;
}

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

main {
  max-width: 1200px;
  margin: auto;
  padding: 4rem 2rem;
}

section {
  margin-bottom: 5rem;
}

h1 { font-size: 2rem; margin: 0; }
h2 { font-size: 1.5rem; margin-bottom: 1.5rem; }

.split {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.split img {
  width: 100%;
  border-radius: var(--radius);
}

.card {
  background: var(--light-gray);
  padding: 2rem;
  border-radius: var(--radius);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px,1fr));
  gap: 2rem;
}

/* Force 2x2 layout for Research page */
.research-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2.5rem;
}

/* Mobile stacking */
@media (max-width: 900px) {
  .research-grid {
    grid-template-columns: 1fr;
  }
}


.member-card {
  text-align: center;
}

.member-card img {
  width: 180px;
  height: 180px;
  object-fit: cover;
  border-radius: 50%;
  margin-bottom: 1rem;
}

.carousel {
  overflow: hidden;
}

.carousel-track {
  display: flex;
  gap: 3rem;
  animation: scroll 60s linear infinite;
}

.carousel img { height:150px; width:auto; opacity:0.95; object-fit:cover; border-radius:12px; }

@keyframes scroll {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

.publications li {
  margin-bottom: 1rem;
}

footer {
  border-top: 1px solid #e5e7eb;
  padding: 3rem;
  text-align: center;
  color: var(--muted);
}

@media(max-width:900px){
  .split { grid-template-columns: 1fr; }
  nav { justify-content: center; margin-top: 1rem; }
}

/* Research grid cards with images */
.research-grid .card {
  padding: 0;
  overflow: hidden;
}

.research-grid .card img {
  width: 100%;
  height: 360px;        /* smaller height */
  object-fit: contain;    /* fills box nicely */
  display: block;
}

.research-grid .card p {
  padding: 1.2rem;
}

/* Lab Head enhanced styling */
.lab-head {
  text-align: center;
  padding: 2rem 1rem;
}

.lab-head h3 {
  margin-top: 1.2rem;
  font-size: 1.3rem;
  letter-spacing: 1px;
}

.lab-head .designation {
  font-weight: 600;
  margin-top: 0.6rem;
}

.lab-head .affiliation {
  margin-top: 0.4rem;
  color: var(--muted);
}

.lab-head .contact {
  margin-top: 0.8rem;
}

.lab-head .scholar {
  margin-top: 0.6rem;
}

.lab-head a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.lab-head a:hover {
  text-decoration: underline;
}

/* Postdoc styling */
.postdoc-card {
  padding: 2rem 1rem;
  text-align: center;
}

.postdoc-card h3 {
  margin-top: 1.2rem;
  font-size: 1.15rem;
  letter-spacing: 0.8px;
}

.postdoc-card .research-interest {
  margin-top: 0.8rem;
  color: var(--muted);
  line-height: 1.6;
}

.postdoc-card .contact {
  margin-top: 0.8rem;
}

.postdoc-card .scholar {
  margin-top: 0.6rem;
}

.postdoc-card a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.postdoc-card a:hover {
  text-decoration: underline;
}

/* PhD styling */
.phd-card {
  padding: 2rem 1rem;
  text-align: center;
}

.phd-card h3 {
  margin-top: 1.2rem;
  font-size: 1.1rem;
  letter-spacing: 0.8px;
}

.phd-card .research-interest {
  margin-top: 0.8rem;
  color: var(--muted);
  line-height: 1.6;
}

.phd-card .contact {
  margin-top: 0.8rem;
}

.phd-card a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.phd-card a:hover {
  text-decoration: underline;
}

/* Alumni styling */
.alumni-card {
  padding: 2rem 1rem;
  text-align: center;
}

.alumni-card h3 {
  margin-top: 1.2rem;
  font-size: 1.1rem;
  letter-spacing: 0.8px;
}

.alumni-card .position {
  margin-top: 0.8rem;
  color: var(--muted);
  line-height: 1.6;
}

/* IIT Kharagpur text under lab title */
.iit-name {
  margin: 0.3rem 0 0 0;
  font-size: 1.3rem;
  color: #0077cc;        /* blue */
  font-weight: 600;
}

.education-list li {
  margin-bottom: 1.5rem;
  line-height: 1.6;
}