* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
body {
  background: #f0f5fa;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 20px;
}
.container {
  width: 100%;
  max-width: 560px;
}
.screen {
  display: none;
  background: white;
  padding: 36px;
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.06);
}
.screen.active {
  display: block;
}
h1 {
  margin-bottom: 28px;
  font-size: 22px;
  text-align: center;
  color: #2d3748;
}
.form-item {
  margin: 24px 0;
}
.form-item label {
  display: block;
  margin-bottom: 10px;
  font-weight: 500;
  color: #4a5568;
}
#pid {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  font-size: 16px;
  transition: border 0.2s;
}
#pid:focus {
  outline: none;
  border-color: #4299e1;
}
.tip {
  font-size: 13px;
  color: #e53e3e;
  margin-top: 6px;
}
.options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.options button {
  padding: 14px 16px;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  background: white;
  text-align: left;
  cursor: pointer;
  font-size: 15px;
  transition: all 0.2s;
}
/* 选中时的变色效果（核心修复） */
.options button.selected {
  background: #ebf8ff;
  border-color: #4299e1;
  color: #2b6cb0;
}
.options button:hover {
  border-color: #cbd5e0;
}

#start-btn {
  width: 100%;
  padding: 16px;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  margin-top: 28px;
  background: #2d3748;
  color: white;
  cursor: pointer;
  transition: background 0.2s;
}
/* 禁用状态样式 */
#start-btn:disabled {
  background: #a0aec0;
  cursor: not-allowed;
}
.round {
  text-align: center;
  font-size: 14px;
  color: #718096;
  margin-bottom: 16px;
}
.scene {
  line-height: 1.8;
  padding: 20px;
  background: #f7fafc;
  border-radius: 12px;
  margin-bottom: 20px;
  white-space: pre-line;
}
.choices {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.choice-btn {
  padding: 14px 16px;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  background: white;
  cursor: pointer;
  font-size: 15px;
  transition: all 0.2s;
}
.choice-btn:hover {
  border-color: #9f7aea;
  background: #faf5ff;
}
#feedback {
  margin-top: 16px;
  padding: 14px 16px;
  background: #e6fffa;
  border-radius: 10px;
  font-size: 14px;
  color: #234e52;
}
#end-text {
  line-height: 1.8;
  padding: 20px;
  background: #fef7fb;
  border-radius: 12px;
  color: #2d3748;
  font-size: 16px;
}