body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f4f6f9;
}

header {
  background: #0a4d8c;
  color: white;
  padding: 30px;
  text-align: center;
}

nav {
  background: #083b6f;
  padding: 10px;
  text-align: center;
}

nav a {
  color: white;
  margin: 8px;
  text-decoration: none;
  font-weight: bold;
}

nav a:hover {
  text-decoration: underline;
}

.hero, .content {
  padding: 30px;
  max-width: 900px;
  margin: auto;
}

.gallery img, .scroll-img img {
  width: 100%;
  margin: 15px 0;
  border-radius: 8px;
}

.btn-back {
  display: inline-block;
  margin-top: 20px;
  background: #0a4d8c;
  color: white;
  padding: 10px 20px;
  text-decoration: none;
  border-radius: 5px;
}

footer {
  background: #083b6f;
  color: white;
  text-align: center;
  padding: 15px;
}

/* Responsif */
@media (max-width: 600px) {
  nav a {
    display: block;
    margin: 5px 0;
  }
}
/* ===== TOPIC CARDS ===== */
.topics {
  background: #ffffff;
  padding: 40px 20px;
  text-align: center;
}

.topics h2 {
  margin-bottom: 30px;
  color: #0a4d8c;
}

.card-container {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.card {
  background: #f4f6f9;
  padding: 25px;
  width: 260px;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

.card h3 {
  color: #083b6f;
}

.card p {
  font-size: 14px;
  line-height: 1.6;
}

.btn-card {
  display: inline-block;
  margin-top: 15px;
  background: #0a4d8c;
  color: #fff;
  padding: 8px 15px;
  border-radius: 5px;
  text-decoration: none;
  font-size: 14px;
}

.btn-card:hover {
  background: #083b6f;
}

/* ===== IMPORTANCE SECTION ===== */
.importance {
  background: #e8f1fb;
  padding: 40px 25px;
  text-align: center;
}

.importance h2 {
  color: #0a4d8c;
  margin-bottom: 15px;
}

.importance p {
  max-width: 800px;
  margin: auto;
  line-height: 1.8;
}

/* RESPONSIVE */
@media (max-width: 768px) {
  .card-container {
    flex-direction: column;
    align-items: center;
  }
}
/* === tambahan halaman pengertian === */

.subtitle {
  color: #666;
  margin-bottom: 18px;
  font-style: italic;
}

.highlight-box {
  background: #eef5ff;
  border-left: 4px solid #0a4d8c;
  padding: 15px;
  margin: 25px 0;
  border-radius: 6px;
}

.page-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 30px;
}

.btn-next {
  background: #083b6f;
  color: #fff;
  padding: 10px 18px;
  text-decoration: none;
  border-radius: 5px;
}

.btn-next:hover {
  background: #062d55;
}