body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  text-align: center;
  background-color: #fafafa;
}

h1 {
  font-size: 2em;
  color: #333;
  margin-top: 30px;
  margin-bottom: 25px;
}

.papers-container {
  width: 100%;
  max-width: 850px; /* narrower page layout */
  margin: 0 auto 60px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 30px;
}

.paper {
  width: 80%; /* narrower card width */
  max-width: 600px; /* limit box width */
  background-color: #fff;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
  overflow: hidden;
  text-align: left;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.paper:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 15px rgba(0, 0, 0, 0.12);
}

.paper img {
  width: 100%;
  max-height: 160px; /* smaller but still clear */
  object-fit: contain; /* show entire image */
  background-color: #f9f9f9; /* subtle frame color */
  display: block;
  padding: 5px;
}

.paper-info {
  padding: 15px 20px;
}

.paper-title {
  font-size: 1.1em;
  font-weight: bold;
  color: #111;
  margin: 0 0 8px;
}

.paper-details {
  font-size: 0.9em;
  color: #666;
  margin-bottom: 15px;
}

.paper-buttons {
  display: flex;
  gap: 10px;
}

.btn {
  display: inline-block;
  padding: 7px 12px;
  border-radius: 6px;
  background-color: #007acc;
  color: #fff;
  text-decoration: none;
  font-size: 0.85em;
  transition: background-color 0.2s ease;
}

.btn:hover {
  background-color: #005fa3;
}

.code-btn {
  background-color: #4caf50;
}

.code-btn:hover {
  background-color: #3a913d;
}