body {
  font-family: Arial, sans-serif;
  background: #f4f4f4;
  padding: 20px;
  margin: 0;
}

.quiz-box {
  max-width: 850px;
  margin: auto;
  background: white;
  padding: 25px;
  border-radius: 14px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.12);
}

.top-bar {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
}

h1 {
  margin-top: 0;
}

#question {
  line-height: 1.35;
}

.answer {
  padding: 14px;
  margin: 12px 0;
  border: 1px solid #ccc;
  border-radius: 10px;
}

.answer label {
  cursor: pointer;
}

.explain-btn {
  margin-top: 10px;
  padding: 7px 10px;
  cursor: pointer;
}

.explanation {
  display: none;
  background: #eef3ff;
  padding: 12px;
  margin-top: 10px;
  border-left: 4px solid #456;
  border-radius: 6px;
}

.button-row {
  margin-top: 18px;
}

button {
  padding: 10px 14px;
  cursor: pointer;
  border-radius: 8px;
  border: 1px solid #999;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.small-btn {
  padding: 8px 10px;
}

#feedback {
  font-weight: bold;
  min-height: 24px;
}

.correct {
  color: green;
}

.incorrect {
  color: crimson;
}

.progress-wrap {
  margin: 15px 0;
}

.progress-bar {
  width: 100%;
  height: 12px;
  background: #ddd;
  border-radius: 999px;
  overflow: hidden;
}

#progressFill {
  height: 100%;
  width: 0%;
  background: #333;
  transition: width 0.3s ease;
}

#scoreText {
  font-weight: bold;
}


.hidden {
  display: none;
}

#usernameInput {
  width: 100%;
  max-width: 350px;
  padding: 12px;
  font-size: 16px;
  border: 1px solid #aaa;
  border-radius: 8px;
}

#resumeArea {
  margin-top: 18px;
}

#userDisplay {
  font-weight: bold;
}