body {
  font-family: "Segoe UI", Tahoma, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #a4da78;
}
header {
  background-image: url("TrangAn.jpg");
  height: 60vh;
  position: relative;
}
.banner {
  width: 100%;
  height: 400px;
  background-image: url("img/TrangAn.jpg"); 
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}
.banner .overlay {
  background: rgba(0, 0, 0, 0.45);
  padding: 60px 80px;
  text-align: center;
  border-radius: 10px;
  color: #fff;
}
.banner h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
}
.banner p {
  font-size: 1.2rem;
  margin-bottom: 20px;
}
.banner .btn {
  background: #ffc107;
  padding: 12px 24px;
  color: #000;
  font-weight: bold;
  border-radius: 8px;
  text-decoration: none;
  transition: 0.3s;
}
.banner .btn:hover {
  background: #ffca2c;
  transform: scale(1.05);
}
nav {
  background-color: #333;
}
nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  padding: 0;
  margin: 0;
}
nav ul li {
  position: relative;
}
nav ul li a {
  color: white;
  text-decoration: none;
  display: block;
  padding: 14px 20px;
  transition: background 0.3s;
}
nav ul li a:hover {
  background-color: #81807f;
}
nav ul li ul {
  display: none;
  position: absolute;
  top: 48px;
  left: 0;
  background-color: #444;
  min-width: 180px;
  list-style: none;
  padding: 0;
}
nav ul li:hover ul {
  display: block;
}
main{
    display: flex;
    gap: 20px;
    padding: 20px;
}
main section{
    flex: 3;
    background-color: white;
    padding: 20px;
    border-radius: 5px;
}
aside{
    flex: 1;
    background-color: #ecdec7;
    padding: 20px;
    border-radius: 5px;
}
aside ul{
    list-style: square inside;
}
footer{
    background-color: #4a4f1e;
    color: white;
    text-align: center;
    padding: 15px 0;
    margin-top: 20px;
    font-size: 0.9em;
}