* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Arial;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background: #eee;
}

.container {
  width: 100%;
  max-width: 900px;
  height: 90vh;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
  background: white;
  display: flex;
  flex-direction: column;
}

.screen {
  display: none;
  height: 100%;
}

.active {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 20px;
}

.start {
  background: linear-gradient(135deg, #7b2ff7, #a94bff);
  color: white;
  align-items: center;
  text-align: center;
}

.start input {
  padding: 12px;
  width: 80%;
  margin: 20px 0;
  border: none;
  border-radius: 5px;
}

.start button {
  padding: 12px 20px;
  background: #ff4d6d;
  border: none;
  color: white;
  cursor: pointer;
  border-radius: 5px;
}

.quiz {
  background: linear-gradient(180deg, #1e3c72, #2a5298);
  color: white;
}

.question {
  font-size: 18px;
  margin-bottom: 20px;
}

.option {
  background: #ddd;
  color: black;
  padding: 12px;
  margin: 8px 0;
  border-radius: 6px;
  cursor: pointer;
  text-align: center;
}

.correct { background: #00c853 !important; color: white; }
.wrong { background: #ff1744 !important; color: white; }

.timer {
  text-align: center;
  margin-top: 15px;
}

.score {
  align-items: center;
  text-align: center;
  background: linear-gradient(135deg, #7b2ff7, #a94bff);
  color: white;
}

.score h1 {
  margin-bottom: 20px;
}

.score button {
  padding: 10px 20px;
  background: #ff4d6d;
  border: none;
  color: white;
  border-radius: 5px;
  cursor: pointer;
}