body {
  background-color: gray;
  font-size: 44px
}

.wrapper {
    display: flex;
    height: 100vh;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.wrapper h2 {
  margin: 0;
}

.break-session-length {
    display: flex;
    width: 700px;
    justify-content: space-between;
}

button {
  border: none;
  padding: 8px;
  font-size: 28px;
  border-radius: 4px;
}

div > button {
  color: white;
  background-color: green;
}

div button:nth-child(2) {
  color: #000;
  background-color: yellow;
}

strong {
  margin: 0 8px;
}

.timer {
  border: 2px solid #ccc;
  border-radius: 10px;
  text-align: center;
  margin: 20px 0;
  padding-top: 10px;
}

.timer-wrapper > button {
  margin-left: 10px
}