/* Research Section Styling */
.research-section {
  padding: 80px 0;
  background: #f9f9f9;
}

.research-section .section-title h1 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 15px;
  color: #333;
}

.research-section .section-title p {
  color: #777;
  font-size: 18px;
  margin-bottom: 50px;
}

.research-content {
  max-width: 900px;
  margin: auto;
}

.research-part {
  margin-bottom: 50px;
  padding: 30px;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 8px 20px rgba(0,0,0,0.08);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.research-part:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 28px rgba(0,0,0,0.12);
}

.research-part h2 {
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 15px;
  color: #2c3e50;
}

.research-part p {
  font-size: 16px;
  line-height: 1.7;
  color: #555;
}

/* Research Header with Arrow */
.research-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  padding: 10px 5px;
}

.research-header h2 {
  margin: 0;
  font-size: 24px;
  color: #2c3e50;
}

.research-header .arrow {
  font-size: 20px;
  transition: transform 0.3s ease;
}

/* Collapsible Content */
.research-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  padding: 0 10px;
}

.research-body.open {
  max-height: 10000px; /* large enough to fit content */
  padding: 20px 10px;
}

.diagram-image {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 60px auto;
  padding: 20px;
  max-width: 100%;
  background: #fff; /* optional clean background */
  border-radius: 12px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.1);
  overflow: hidden;
}

.diagram-image img {
  max-width: 100%;
  height: auto;
  object-fit: contain;
  transition: transform 0.3s ease;
  border-radius: 8px;
}

/* Optional hover effect */
.diagram-image img:hover {
  transform: scale(1.02);
}