body {
  font-family: "Segoe UI", "Roboto", sans-serif;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  color: #e0f2f1;
}

header {
  backdrop-filter: blur(10px);
  padding: 40px 20px;
  text-align: center;
}

header h1 {
  font-size: 3em;
  color: #66fcf1;
  text-shadow: 0 0 10px #45a29e;
}

nav {
  padding: 10px;
  text-align: center;
  border-bottom: 1px solid #1f2833;
}

nav a {
  margin: 0 15px;
  text-decoration: none;
  color: #66fcf1;
  font-weight: bold;
  font-size: 1.1em;
  transition: color 0.3s ease;
}

nav a:hover {
  color: #ffffff;
}

main {
  max-width: 800px;
  margin: 2px auto;
  background: rgba(255, 255, 255, 0.05);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 4px 20px rgba(0, 255, 255, 0.1);
  backdrop-filter: blur(6px);
}

h2 {
  font-size: 1.8em;
  color: #66fcf1;
  margin-bottom: 20px;
  border-left: 5px solid #45a29e;
  padding-left: 10px;
}

.tree ul {
  list-style: none;
  padding-left: 20px;
}

.tree li {
  position: relative;
  padding-left: 24px;
  margin: 10px 0;
}

.tree li a::before {
  position: absolute;
  left: 0;
  color: #45a29e;
}

.tree a {
  color: #ffffff;
  text-decoration: none;
  font-weight: 500;
}

.tree a:hover {
  color: #66fcf1;
}

footer {
  text-align: center;
  padding: 20px;
  font-size: 0.9em;
  color: #888;
  margin-top: 40px;
}

.image-box {
  text-align: center;
  margin-top: 20px;
}

.image-box img {
  width: 80%;
  max-width: 500px;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}