/* Header */
.header {
  background: #111;
  color: #fff;
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

.header .container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header .logo {
  color: #fff;
  font-weight: 700;
  font-size: 1.2rem;
  text-decoration: none;
}

.header .nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 1rem;
}

.header .nav a {
  color: #fff;
  text-decoration: none;
  font-size: 1rem;
  transition: color 0.3s;
}

.header .nav a:hover {
  color: #3498db;
}

/* Body */
body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 0;
  background: #f5f7fa;
}

/* Nội dung chính */
main {
  display: flex;
  justify-content: center;
  padding: 3rem 1rem;
}

.feature-list {
  background: #fff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.1);
  width: 100%;
  max-width: 700px;
}

.feature-list h1 {
  text-align: center;
  margin-bottom: 2rem;
  font-size: 1.8rem;
  color: #333;
}

.update-item {
  margin-bottom: 2rem;
  padding: 1.2rem;
  border-left: 4px solid #3498db;
  background: #f9fcff;
  border-radius: 8px;
}

.update-item h2 {
  margin: 0 0 0.8rem;
  font-size: 1.3rem;
  color: #222;
}

.update-item h2 span {
  font-size: 0.95rem;
  font-weight: normal;
  color: #666;
}

.update-item ul {
  margin: 0;
  padding-left: 1.2rem;
}

.update-item ul li {
  margin-bottom: 0.5rem;
  color: #444;
  font-size: 1rem;
}