:root {
  --primary: #1B5E20;
  --accent: #4CAF50;
  --light: #f5f7f5;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: var(--light);
  color: #222;
}

header {
  background: white;
  padding: 15px 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 3px solid var(--primary);
}

nav a {
  margin: 0 12px;
  text-decoration: none;
  color: var(--primary);
  font-weight: bold;
}

.hero {
  padding: 80px 40px;
  background: linear-gradient(to right, #1B5E20, #4CAF50);
  color: white;
}

.section {
  background: white;
  margin: 30px;
  padding: 40px;
  border-radius: 8px;
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 25px;
}

.card {
  background: #f9f9f9;
  padding: 20px;
  border-left: 5px solid var(--accent);
}

footer {
  background: var(--primary);
  color: white;
  text-align: center;
  padding: 20px;
}

.collab-list {
  margin-top: 15px;
  padding-left: 25px;
}

.collab-list li {
  margin-bottom: 8px;
  line-height: 1.6;
}

.card {
  background: white;
  padding: 20px;
  border-radius: 8px;
  border-left: 4px solid #4CAF50;
  overflow: hidden;
}

.research-img {
  width: 100%;
  height: 180px;
 object-fit: contain;   /* ✅ GIỮ ĐỦ ẢNH */
  background: #f7f7f7;   /* nền xám nhẹ */

  border-radius: 6px;
  margin-bottom: 12px;
  display: block;
}

.card p {
  text-align: justify;
  hyphens: auto;
}

.img-box {
  width: 100%;
  height: 260px;          /* tăng chiều cao */
  background: #f7f7f7;    /* nền trung tính */
  display: flex;
  align-items: center;
  justify-content: center;
}

.img-box img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
}

.hero h1 {
  font-size: 52px;      /* tăng size tiêu đề */
  font-weight: 700;
  margin-bottom: 10px;
  line-height: 1.15;
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 42px;
  }
}

.hero h1 {
  letter-spacing: 0.5px;
}

/* ===== Group headers ===== */
.member-group-title {
  margin: 35px 0 12px;
  font-size: 22px;
  font-weight: 700;
  color: var(--primary);
  border-bottom: 2px solid var(--accent);
  padding-bottom: 4px;
}

/* ===== Member list ===== */
.member-list {
  list-style: disc;
  padding-left: 30px;   /* indent */
  margin: 0 0 20px 0;
}

/* ===== Member item ===== */
.member-item {
  margin-bottom: 8px;
  color: #000;          /* tên màu đen */
}

/* ===== Member name ===== */
.member-name {
  font-weight: 500;
}

/* ===== Profile link ===== */
.member-item a {
  margin-left: 8px;
  font-size: 14px;
  color: var(--accent);
  text-decoration: none;
}

.member-item a:hover {
  text-decoration: underline;
}

/* ===== Activities Accordion ===== */

.activity-year {
  margin-top: 40px;
  margin-bottom: 15px;
  font-size: 22px;
  color: var(--primary);
  border-bottom: 2px solid var(--accent);
  padding-bottom: 4px;
}

.activity-album {
  margin-bottom: 15px;
  border-left: 4px solid var(--accent);
  padding-left: 15px;
}

.activity-album summary {
  cursor: pointer;
  font-size: 16px;
  padding: 8px 0;
  list-style: none;
}

.activity-album summary::-webkit-details-marker {
  display: none;
}

.activity-meta {
  color: #666;
  font-size: 14px;
  margin-left: 10px;
}

/* ===== Gallery inside album ===== */
.activity-gallery {
  margin-top: 15px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 25px;
}

.activity-gallery img {
  width: 100%;
  height: 300px;
  object-fit: cover;   /* giữ đủ ảnh */
  background: #f5f5f5;
  border-radius: 6px;
}

.activity-album summary::before {
  content: "▸";
  display: inline-block;
  margin-right: 8px;
  transition: transform 0.2s ease;
}

.activity-album[open] summary::before {
  transform: rotate(90deg);
}

.pi .member-name {
  font-weight: 700;
}

.member-profile{
  display:flex;
  gap:30px;
  align-items:center;
  margin-bottom:30px;
}

.member-photo{
  width:180px;
  border-radius:10px;
}

.member-info h2{
  margin:0;
}

.member-info p{
  margin-top:8px;
  font-size:16px;
}

.member-links{
  margin-top:10px;
  line-height:1.6;
}

.member-links a{
  color:var(--primary);
  text-decoration:none;
}

.member-links a:hover{
  text-decoration:underline;
}

.project-list li{
  margin-bottom:18px;
}

.project-list em{
  color:#555;
  display:block;
  margin-top:4px;
}