.subject-grid {
  display: grid;
  grid-auto-rows: auto; 
  gap: 5px; 
  height: 100%; 
}
.pdf-containers {
  box-sizing: border-box;
  font-size: 3vw;
  text-decoration: none;
  height: 100%;
  width: 100%;
  max-width: 100%;
  max-height: 100%;
  color: white;
  background-color: rgb(40, 40, 40);
  border: 2px solid rgb(60, 60, 60);
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.pdf-containers a {
  padding-top: 10px;
  padding-bottom: 10px;
  box-sizing: border-box;
  font-size: 3vw;
  text-decoration: none;
  color: white;
  height: 100%;
  width: 100%;
  max-width: 100%;
  max-height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  transition: 0.15s;
}
.pdf-containers a:hover {
  border: 2px solid white;
  border-radius: 7px;
}
.pdf-containers a:active {
  border: 2px solid white;
  border-radius: 7px;
  color: rgb(40, 40, 40);
  background-color: white;
}
@media (max-width: 450px) {
  .subject-grid {
    grid-template-columns: 1fr;
    height: 70%;
    font-size: 5vw;
  }
}
@media (min-width: 451px) and (max-width: 750px) {
  .subject-grid {
    grid-template-columns: 1fr 1fr;
  }
}
@media (min-width: 751px) and (max-width: 999px) {
  .subject-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
}
@media (min-width: 1000px) {
  .subject-grid {
    grid-template-columns: 1fr 1fr 1fr 1fr;
  }
}
@media (max-width: 1000px) {
  .pdf-containers {
    font-size: 16px;
  }
}
@media (min-width: 1500px) {
  .pdf-containers {
    font-size: 26px;
  }
}
.content-section {
  text-align: center;
  margin-bottom: 20px;
}
.aim-features {
  text-align: center;
}
.aim-text {
  font-size: 30px;
  margin-bottom: 10px;
}
.list-features {
  display: inline-block;
}
.features-text {
  font-size: 30px;
  font-weight: 600;
  margin: 0;
}
.list-features-text {
  text-align: left;
}
.list-features-text ul {
    margin: 0;
}