body {
  margin: 0;
  padding: 20px;
  background: #111827;
  color: white;
  font-family: Arial, sans-serif;
}

.exam {
  max-width: 450px;
  margin: 20px auto;
  padding: 22px;
  background: #1f2937;
  border-radius: 18px;
  box-shadow: 0 8px 30px #0005;
}

h1 { font-size: 25px; }

.info {
  display: flex;
  justify-content: space-between;
  color: #93c5fd;
}

.bar {
  height: 8px;
  background: #374151;
  border-radius: 10px;
  margin: 15px 0 25px;
  overflow: hidden;
}

#fill {
  height: 100%;
  width: 20%;
  background: #22c55e;
  transition: width 0.3s;
}

#answers {
  display: grid;
  gap: 10px;
}

.answer {
  padding: 14px;
  background: #374151;
  color: white;
  border: 2px solid transparent;
  border-radius: 10px;
  text-align: left;
  font-size: 16px;
}

.answer:disabled { opacity: 1; }
.answer.correct { border-color: #22c55e; background: #14532d; }
.answer.wrong { border-color: #ef4444; background: #7f1d1d; }

button#next, button#restart {
  width: 100%;
  padding: 13px;
  margin-top: 20px;
  border: 0;
  border-radius: 10px;
  background: #22c55e;
  color: #111827;
  font-size: 16px;
  font-weight: bold;
}

button:disabled { opacity: 0.5; }
#feedback { min-height: 20px; }
#result { text-align: center; }
#result h2 { font-size: 32px; }