style.css

.projects {
  width: 200px;
  padding: 10px;
  border: 1px solid #c8c2c2;
  border-radius: 4px;
  font-size: 20px;
  text-decoration: none;
  background-color: #ea9393;
  color: rgb(185, 237, 12);
}

.collapsible {
  background-color: #777;
  color: white;
  cursor: pointer;
  padding: 18px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 15px;
}

.active,
.collapsible:hover {
  background-color: #555;
}

.content {
  padding: 0 18px;
  display: none;
  overflow: hidden;
  background-color: #f1f1f1;
}

#outer {
  width: 200px;
  background-color: red;
  padding: 20px;
}

#middle {
  background-color: green;
  padding: 20px;
}

#inner {
  background-color: blue;
  padding: 20px;
}

#outer1 {
  width: 200px;
  background-color: red;
  padding: 20px;
}

#middle1 {
  background-color: green;
  padding: 20px;
}

#inner1 {
  background-color: blue;
  padding: 20px;
}

.main-box {
  border: 1px solid black;
  width: 200px;
  padding: 10px;
}