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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: #f0f7ff;
  color: #333;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  padding: 16px;
}

#app {
  width: 100%;
  max-width: 480px;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  overflow: hidden;
}

#header {
  background: linear-gradient(135deg, #4a90e2, #357abd);
  color: #fff;
  padding: 20px;
  text-align: center;
}

#header h1 {
  font-size: 22px;
  margin-bottom: 12px;
}

#progress-bar {
  position: relative;
  height: 24px;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 12px;
  overflow: hidden;
}

#progress-fill {
  height: 100%;
  width: 1%;
  background: #ffd166;
  border-radius: 12px;
  transition: width 0.3s ease;
}

#progress-text {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: bold;
}

#game-area {
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

#sentence-card {
  background: #f8fbff;
  border: 2px solid #e1ecf7;
  border-radius: 12px;
  padding: 24px 20px;
  text-align: center;
}

#sentence-text {
  font-size: 20px;
  line-height: 1.6;
  color: #2c3e50;
  margin-bottom: 16px;
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
}

#record-area, #result-area, #action-area {
  text-align: center;
}

.btn {
  display: inline-block;
  padding: 14px 28px;
  font-size: 18px;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  background: #e1ecf7;
  color: #357abd;
  font-weight: bold;
  transition: background 0.2s, transform 0.1s;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: #4a90e2;
  color: #fff;
}

.btn-primary:hover {
  background: #357abd;
}

.btn-primary:disabled {
  background: #b0c4de;
  cursor: not-allowed;
  transform: none;
}

#record-status {
  margin-top: 12px;
  font-size: 14px;
  color: #666;
}

#score-text {
  font-size: 20px;
  font-weight: bold;
  color: #2c3e50;
}

#result-msg {
  margin-top: 8px;
  font-size: 16px;
  color: #27ae60;
  min-height: 24px;
}