body, html {
  height: 100%;
  margin: 0;
  display: flex;
  flex-direction: column;
  font-family: Arial, sans-serif;
}

.container {
  height: 100%;
  display: flex;
  flex-direction: column;
}

.top {
  display: flex;
  flex: 1;
}

.left, .right {
  flex: 1;
  padding: 20px;
  box-sizing: border-box;
}

.left {
  display: flex;
  flex-direction: column;
  justify-content: space-evenly;
  background-color: lightgreen;
  color: black;
  text-align: center;
  overflow-y: auto;
  height: 60vh;
}

.right {
  background-color: gray;
  border-left: 1px solid black;
  overflow-y: auto;
  height: 60vh;
}

.bottom {
  height: 50%;
  background-color: black;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
}

#clock {
  font-size: calc(30vh);
  text-align: center;
  color: white;
}

.timer {
  font-size: calc(15vh);
}

.mode {
  font-size: 60px;
  text-transform: uppercase;
}

.round {
  font-size: 30px;
}

.controls {
  margin-top: 10px;
}

.duration-controls {
  text-align: center;
}

.duration-controls button {
  margin: 0 5px;
  text-align: center;
}

.workout-step.highlighted {
  background-color: #880;
}


button {
  display: inline-block;
  padding: 0.5em 1em;
  margin: 0.2em;
  border-radius: 4px;
  border: 1px solid #ccc;
  background-color: #f3f3f3;
  color: #333;
  text-align: center;
  text-decoration: none;
  font-size: 16px;
  font-family: sans-serif;
  cursor: pointer;
  transition: background-color 0.3s ease, box-shadow 0.2s ease;
  outline: none;
}

button:hover {
  background-color: #e9e9e9;
}

button:active {
  background-color: #ddd;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.2);
}

button:disabled {
  background-color: #f9f9f9;
  color: #aaa;
  border-color: #ddd;
  cursor: not-allowed;
}

@media (max-width: 768px) {
  .container {
    flex-direction: column;
  }

  .top, .left, .right, .bottom {
    flex: none;
    width: 100%;
    height: auto;
    padding: 0;
    display: block;
  }

  .left, .right, .bottom {
    padding-top: 20px;
    padding-bottom: 20px;
  }

  #clock {
    font-size: calc(20vh);
  }

  .timer {
    font-size: calc(6vh);
  }

  .mode {
    font-size: 40px;
  }

  .round {
    font-size: 20px;
  }

  button {
    font-size: 14px;
    padding: 0.4em 0.8em;
  }
}