body {
  font-family: Arial, sans-serif;
  background-color: #f0f8ff;
  color: #034f84;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header {
  text-align: center;
  margin: 50px 0 30px 0;
}

header h1 {
  font-size: 2.5rem;
  margin: 10px 0;
}

header p {
  font-size: 1.2rem;
  margin: 0;
}

.banner {
  max-width: 300px;
  height: auto;
  margin-bottom: 20px;
}

.back-link {
  display: inline-block;
  margin-top: 10px;
  margin-bottom: 30px;
  color: #034f84;
  text-decoration: none;
  font-size: 1rem;
}

.back-link:hover {
  text-decoration: underline;
}

/* Main category bubble buttons */
.bubble-button {
  display: block;
  max-width: 400px;
  margin: 15px auto;
  padding: 20px;
  background: linear-gradient(135deg, #ffb347, #ffcc33);
  color: white;
  text-align: center;
  font-size: 1.3rem;
  font-weight: bold;
  border-radius: 50px;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 5px 10px rgba(0,0,0,0.2);
}

.bubble-button:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 15px rgba(0,0,0,0.3);
}

/* Sub-buttons for resources */
.sub-buttons {
  display: none; /* hidden by default */
  max-width: 400px;
  margin: 10px auto 30px auto;
  text-align: center;
}

.sub-bubble {
  display: block;
  margin: 10px auto;
  padding: 15px 20px;
  max-width: 250px;
  background: linear-gradient(135deg, #00c6ff, #0072ff);
  color: white;
  text-decoration: none;
  font-size: 1.1rem;
  font-weight: bold;
  border-radius: 50px;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.sub-bubble:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 12px rgba(0,0,0,0.3);
}

/* Video container & flashcards */
.video-container, .flashcards-container {
  display: none; /* hidden initially */
  max-width: 500px;
  margin: 15px auto 30px auto;
  text-align: center;
}

/* Flashcards styling */
.flashcards-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 15px;
}

.flashcard {
  background-color: #ffe0b2;
  border-radius: 15px;
  padding: 10px;
  min-width: 120px;
  text-align: center;
  font-weight: bold;
  font-size: 1.1rem;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  transition: transform 0.2s;
}

.flashcard:hover {
  transform: scale(1.05);
}

.flashcard img {
  width: 80px;
  height: 80px;
  object-fit: contain;
  margin-bottom: 5px;
}

.flashcard button {
  margin-top: 5px;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.2rem;
}

.flashcard button:hover {
  color: #ff8c00;
}
/* Center main content */
main {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
}

/* Ensure flashcards wrap nicely and remain centered */
.flashcards-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 15px;
}

/* Video container centered */
.video-container {
  display: flex;
  justify-content: center;
  margin: 15px auto 30px auto;
}