body {
  font-family: Arial, sans-serif;
  background-color: #f4f4f4;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.container {
  background-color: #fff;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  text-align: center;
  max-width: 800px;
  width: 90%;
  box-sizing: border-box;
  margin: 20px;
}

h1 {
  font-size: 24px;
  margin-bottom: 20px;
}

#introPage {
  display: block;
}

#workoutPage {
  display: none;
}

.session-selector {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
}

#sessionSelect {
  padding: 8px;
  font-size: 14px;
  border: 1px solid #ddd;
  border-radius: 5px;
  flex: 1;
}

#startButton {
  padding: 8px 16px;
  font-size: 14px;
  cursor: pointer;
  background-color: #007bff;
  color: #fff;
  border: none;
  border-radius: 5px;
}

#startButton:hover {
  background-color: #0056b3;
}

#presentationContent {
  margin-bottom: 20px;
  text-align: left;
}

#presentationContent h2 {
  color: #007bff;
  font-size: 22px;
  margin-top: 20px;
  margin-bottom: 10px;
}

#presentationContent h3 {
  color: #333;
  font-size: 18px;
  margin-top: 15px;
  margin-bottom: 10px;
}

#imageContainer {
  margin-top: 20px;
  margin-bottom: 20px;
}

.content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

@media (min-width: 768px) {
  .content {
    flex-direction: row;
  }
}

#exerciseContainer {
  flex: 1;
}

.exercise-box {
  background-color: #f9f9f9;
  border: 1px solid #ddd;
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.1);
}

#exerciseDetails {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

#exerciseReps,
#exerciseTime {
  margin: 0;
  font-size: 18px;
}

#playPauseButton {
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
  background-color: #28a745;
  color: #fff;
  border: none;
  border-radius: 5px;
  margin-right: 10px;
}

#nextButton {
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
  background-color: #007bff;
  color: #fff;
  border: none;
  border-radius: 5px;
}

#nextButton:disabled {
  background-color: #ccc;
  cursor: not-allowed;
}

#videoWrapper {
  position: relative;
  width: 100%;
  max-width: 300px;
  margin: 0 auto;
  padding-top: 150%;
  overflow: hidden;
  border-radius: 10px;
}

#exerciseVideo {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

.next-exercises {
  flex: 0 0 250px;
  background-color: #f9f9f9;
  border: 1px solid #ddd;
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.1);
}

.next-exercises h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

#nextExercisesList {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

#nextExercisesList li {
  padding: 10px;
  border-bottom: 1px solid #ddd;
  font-size: 14px;
}

#nextExercisesList li:last-child {
  border-bottom: none;
}

#blockTimer {
  margin-top: 20px;
  font-size: 18px;
  font-weight: bold;
  color: #007bff;
  text-align: center;
}

#finishButton {
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
  background-color: #dc3545;
  color: #fff;
  border: none;
  border-radius: 5px;
  width: 100%;
  margin-top: 20px;
}

#finishButton:hover {
  background-color: #c82333;
}