body {
  font-family: 'Montserrat', sans-serif;
  background: #0b0c2a;
  color: #f0f0f0;
  margin: 0;
  min-height: 100vh;
  position: relative;
  padding-bottom: 6rem;
  box-sizing: border-box;
  overflow-x: hidden;
}

nav{
  z-index: 2;
}

.landing-page {
  background: url("") center/cover no-repeat;
  height: 100vh;
  width: 100%;
  position: absolute;
  top: 0;
  left: 0;
}

.overlay {
  background: #0b0c2a;
  height: 100%;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.landing-content {
  text-align: center;
  color: #f0f0f0;
  position: relative;
}

.landing-content h1 {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.landing-content p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
}

.landing-content button {
  padding: 0.75rem 1.5rem;
  background: var(--subjectColor);
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  color: #333;
  cursor: pointer;
}

.top-bar {
  max-width: 1100px;
  margin: 2rem auto 1rem;
  padding: 0 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--subjectColor);
}

.top-bar h2 {
  font-size: 1.8rem;
  margin: auto;
}

.back-btn {
  background-color: var(--subjectColor);
  border: 1px solid #ccc;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  color: #333;
  text-decoration: none;
  font-weight: 500;
}

.toggle-bar {
  max-width: 900px;
  margin: 0 auto 1rem;
  padding: 0 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  align-items: center;
}

.toggle-button {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: #1f1359;
  border: none;
  position: relative;
  cursor: pointer;
  font-weight: bold;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.toggle-button span {
  position: relative;
  z-index: 2;
  color: #f0f0f0;
}

.toggle-button.green { background-color: #4caf50; }
.toggle-button.red { background-color: #f44336; }

.toggle-button.green.hint::after,
.toggle-button.green.wrong::after {
  content: "";
  position: absolute;
  width: 100%;
  height: 50%;
  left: 0;
  bottom: 0;
  background-color: #aaa; /* grey for hint */
  z-index: 1;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
}

.toggle-button.green.wrong::after {
  background-color: #f44336;
}

.toggle-button.green.hint::after,
.toggle-button.green.wrong::after {
  content: "";
  position: absolute;
  width: 100%;
  height: 50%;
  bottom: 0;
  left: 0;
  z-index: 1;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
}

.toggle-button.green.hint::after { background: #aaa; }
.toggle-button.green.wrong::after { background: #f44336; }


.toggle-button[activity="active"]{
  border: 2px solid white;
}

.container {
  max-width: 800px;
  margin: auto;
  background: #1f1359;
  padding: 1rem 2rem;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

#dynamicProblemImages img, #dynamicExplanationImages img{
  max-height: 200px;
  max-width: 500px;
  margin: 3px;
}

form label {
  display: block;
  margin: 1rem 0;
}

input[type="radio"] {
  margin-right: 8px;
}

.buttons {
  margin-top: 1rem;
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  flex-wrap: wrap;
}

.buttons button,
.result-page .buttons a{
  padding: 0.5rem 1rem;
  background-color: var(--subjectColor);
  color: #333;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  text-decoration: none;
}

#dynamicButtons{
  margin-top: 2rem;
}

.feedback, .hintText {
  margin-top: 0.5rem;
  font-weight: bold;
}

.non-active{
  display: none;
}

#authors{
  display: flex;
  width: 100%;
  text-align: right;
  justify-content: right;
  align-items: right;
  margin: 1rem 0 0 0;
  font-size: 0.8rem;
}

.result-page{
  margin: 2rem auto auto auto;
}

.footer {
  background: #1f1359;
  color: #f0f0f0;
  text-align: center;
  padding: 20px;
  font-size: 0.9em;
  margin-top: 3rem;
  position: absolute;
  width: 100vw;
  bottom: 0;
  box-sizing: border-box;
}


@media(width < 768px){
  .top-bar h2 {
    font-size: 1.5rem;
  }
  .back-btn {
    font-size: 0.8rem;
}

.landing-content h1 {
  font-size: 2rem;
}

  #dynamicProblemImages img, #dynamicExplanationImages img{
    max-height: 150px;
    max-width: 95%;
    margin: 2px;
  }
}