.main-box .h1 {
  color: #1cb5e0;
  margin-left: 5rem;
}
.main-box {
  display: flex;
  flex-direction: column;
    /* stack vertically on small screens */
    gap: 5rem;
    width: 100%;
  gap: 10px;
  height: auto;
  margin-top: 5rem;
}
.main-box .iframe {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  margin: 2%;
  height: 15vh;

}
.main-box .iframe {
  padding: 10px;
  background: #f4f4f4;
  border-radius: 10px;
  height: auto;
}
.biology,
.chemistry,
.mathematics {
  padding: 5%;
  margin-bottom: 5rem;
  max-height: 70vh;
    /* makes section scrollable */
  overflow-y: auto;
    /* enables vertical scrolling */
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
#inline {
  display: flex;
  flex-wrap: wrap;
  margin-top: 10%;
}