body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 105vh;
  overflow-x: hidden;
}

.content-container {
  width: 100%;
  display: flex;
  justify-content: center;
  position: relative;
}

header {
  background-color: #f0f0f0;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  padding: 20px;
  text-align: center;
  width: 100%;
}

h1 {
  margin: 0;
}

.diagram-box {
  background-color: #ffffff;
  border: 1px solid #e0e0e0;
  border-radius: 4px;
  margin: 20px auto;
  padding: 20px;
  width: 80%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  margin-top: 30px;
}

.shape-selection {
  display: block;
}

button {
  font-weight: bold;
  font-size: 18px;
 
}

@media (min-width: 769px) {
  .diagram-box {
    width: 70% !important;
  }

  .shape-selection {
    display: flex;
  }
}

.nav-button {
  background-color: transparent;
  border: none;
  cursor: pointer;
  
}

.nav-text {
  font-size: 14px;
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
}

#prevButton {
  position: relative;
  left: 60px;
}

#nextButton {
  position: relative;
  display: none;
}

#prevText {
  margin-top: 30px;
  left: 40px;
}

#nextText {
  margin-top: 30px;
  right: 70px;
}

.nav-buttons {
  display: flex;
  justify-content: space-around;
  width: 25%;
}

.nav-button {
  background-color: #007bff;
  color: #ffffff;
  cursor: pointer;  
  margin: 0 10px;
  padding: 10px 20px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  transition-duration: 0.4s;
  width: 115px;
}

.nav-button:hover {
  background-color: #0056b3;
  color: white;
}

#hint {
  display: none;
}

#diagram {
  max-height: 350px;
  max-width: 500px;
  margin: 0 auto;
  margin-bottom: 40px;
}

#hintButton {
  background-color: rgb(229 231 235);
  border: none;
  color: rgb(31 41 55);
  cursor: pointer;  
  margin: 0 10px;
  margin-top: 20px;
  padding: 10px 20px;
  text-align: center;
  text-decoration: none;
  display: block;
  transition-duration: 0.4s;
  width: 115px;
}

#hintButton:hover {
  background-color: rgb(209 213 219);
  color: rgb(31 41 55);
}

#diagramTitle {
  padding: 20px;
  text-align: center;
}

#diagramTitle.centered {
  display: flex;
  justify-content: center;
  align-items: center;
}

.centered {
  height: 50vh;
}

#explanation {
  padding-top: 10px;
  padding-bottom: 10px;
}

#explanation,
#hint {
  font-size: 1.2rem;
  max-width: 40vw;
}

@keyframes fadeIn {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

.fade-in {
  display: block;
  margin-top: 15px;
  animation: fadeIn 1s;
}
.shape-item {
  display: flex;
  align-items: center;
  margin-right: 10px;
  text-align: center;
}

.shape-item span {
  display: block;
  margin-bottom: 35px;
  padding: 5px;
}

@keyframes fadeIn {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

.fade-in {
  animation: fadeIn 1s;
}

@keyframes fadeInBorder {
  0% {
    border-color: transparent;
  }
  100% {
    border-color: rgba(0, 123, 255, 0.35);
  }
}

.shape-option {
  cursor: pointer;
  height: 115px;
  border: 3px solid transparent;
  transition: border-color 0.2s ease-in-out, opacity 0.2s ease-in-out;
}

.shape-option:hover {
  border-color: rgba(0, 123, 255, 0.35);
  transition: border-color 0.2s ease-in-out, opacity 0.2s ease-in-out;
}

.difficulty-selection {
  padding-top: 30px;
  width: 200px;
  margin: 0 auto;
  text-align: center;
}

.difficulty-selection label {
  padding-bottom: 10px;
  display: block;
}

.difficulty-selection select {
  width: 100%;
  padding: 10px;
  border: none;
  border-radius: 4px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  background-color: #f0f0f0;
  font-size: 16px;
  color: #333;
}

.difficulty-selection {
  display: none;
}