/* Basic resets */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
  color: #333;
}

header.hero {
  /* Use the collaboration background image on the hero section */
  position: relative;
  color: #fff;
  text-align: center;
  padding: 60px 20px;
  background-image: url('images/collaboration_bg.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

/* Overlay to improve readability on hero image */
header.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 0;
}

header.hero .overlay {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  z-index: 1;
}

/* Hero text styling */
header.hero .overlay h1 {
  font-size: 3rem;
  font-weight: 700;
}

header.hero .overlay .tagline {
  font-size: 1.8rem;
  margin-top: 10px;
  font-weight: 500;
}

nav.navbar {
  background: #333;
}

nav.navbar ul {
  list-style: none;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
}

nav.navbar li {
  margin: 0 15px;
}

nav.navbar a {
  display: block;
  padding: 15px 10px;
  color: #fff;
  text-decoration: none;
  font-weight: bold;
  transition: background 0.3s, color 0.3s;
}

nav.navbar a:hover,
nav.navbar a:focus {
  background: #4a90e2;
  color: #fff;
}

.section {
  padding: 40px 20px;
  max-width: 1000px;
  margin: 0 auto;
}

.section h2 {
  margin-bottom: 15px;
  font-size: 2rem;
  color: #333;
}

/* Model cards grid */
.model-grid {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin-top: 20px;
}

.model-card {
  position: relative;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  cursor: pointer;
  transition: transform 0.3s ease;
  background: #f5f5f5;
}

.model-card:hover {
  transform: translateY(-4px);
}

.model-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
  transition: height 0.3s ease;
}

.model-card .model-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.6);
  color: #fff;
  padding: 10px 15px;
  text-align: left;
  transition: background 0.3s ease;
}

.model-card .model-overlay h3 {
  font-size: 1.3rem;
  margin: 0;
}

.model-card .model-detail {
  display: none;
  background: #fff;
  padding: 15px;
  color: #333;
}

.model-card .model-detail h4 {
  margin-top: 0;
  font-size: 1.2rem;
}

/* Links inside model detail */
.model-detail a {
  color: #4a90e2;
  text-decoration: underline;
}

.model-detail a:hover {
  text-decoration: none;
}

/* When a card is active, shrink image height to allow more room for details */
.model-card.active img {
  height: 100px;
}

.model-card.active .model-detail {
  display: block;
}

.model-card.active .model-overlay {
  background: rgba(0, 0, 0, 0.8);
}

/* Increase card height when active to provide more space for text */
/* Increase card height when active */
.model-card.active {
  min-height: 380px;
}

.accordion {
  border-top: 1px solid #ddd;
}

.accordion-item {
  border-bottom: 1px solid #ddd;
}

.accordion-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 15px;
  font-size: 1.2rem;
  background: #f5f5f5;
  border: none;
  outline: none;
  cursor: pointer;
  transition: background 0.3s;
}

.accordion-header:hover {
  background: #e0e0e0;
}

.accordion-content {
  display: none;
  padding: 15px;
  animation: fadeIn 0.3s ease-in-out;
}

.accordion-content ul {
  list-style: disc;
  margin-left: 20px;
}

.cases {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.case {
  background: #f9f9f9;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.contact-form {
  max-width: 600px;
  margin: 20px auto;
  display: flex;
  flex-direction: column;
}

.contact-form label {
  margin-top: 10px;
  font-weight: bold;
}

.contact-form input,
.contact-form textarea {
  padding: 10px;
  margin-top: 5px;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-size: 1rem;
}

.contact-form button {
  margin-top: 15px;
  padding: 10px 20px;
  border: none;
  background: #4a90e2;
  color: #fff;
  font-size: 1rem;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.3s;
}

.contact-form button:hover {
  background: #357ab8;
}

footer {
  background: #333;
  color: #fff;
  text-align: center;
  padding: 20px;
  font-size: 0.9rem;
}

/* Detail items styling */
.detail-item {
  margin-bottom: 30px;
}
.detail-item h3 {
  margin-bottom: 10px;
  font-size: 1.4rem;
}
.detail-item p {
  font-size: 1rem;
  line-height: 1.5;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}