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

body {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);
  font-family: 'Arial', sans-serif;
}

.container {
  width: 90%;
  max-width: 800px;
}

.heart-monitor {
  position: relative;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5),
              inset 0 0 20px rgba(0, 255, 157, 0.1);
  border: 2px solid rgba(0, 255, 157, 0.2);
}

svg {
  width: 100%;
  height: auto;
  display: block;
  filter: drop-shadow(0 0 8px rgba(0, 255, 157, 0.6));
}

/* 心電図ライン */
#ecg-line {
  fill: none;
  stroke: #00ff9d;
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 600;
  stroke-dashoffset: 600;
  animation: ecgFlow 3s linear infinite;
}

@keyframes ecgFlow {
  0% {
    stroke-dashoffset: 600;
  }
  100% {
    stroke-dashoffset: 0;
  }
}

/* ハートアイコン */
#heart-icon {
  transform-origin: center;
  animation: heartbeat 3s ease-in-out infinite;
}

#heart-icon path {
  fill: #ff4d6d;
  filter: drop-shadow(0 0 10px rgba(255, 77, 109, 0.8));
}

@keyframes heartbeat {
  0%, 100% {
    transform: scale(1);
    opacity: 0.7;
  }
  10% {
    transform: scale(1.3);
    opacity: 1;
  }
  20% {
    transform: scale(1);
    opacity: 0.8;
  }
  30% {
    transform: scale(1.3);
    opacity: 1;
  }
  40% {
    transform: scale(1);
    opacity: 0.7;
  }
}

/* BPM表示 */
.bpm-display {
  position: absolute;
  top: 20px;
  right: 40px;
  text-align: right;
}

.bpm-value {
  display: block;
  font-size: 3rem;
  font-weight: bold;
  color: #00ff9d;
  text-shadow: 0 0 20px rgba(0, 255, 157, 0.8);
  line-height: 1;
  animation: bpmPulse 3s ease-in-out infinite;
}

.bpm-label {
  display: block;
  font-size: 1rem;
  color: rgba(0, 255, 157, 0.7);
  margin-top: 5px;
  letter-spacing: 3px;
}

@keyframes bpmPulse {
  0%, 100% {
    opacity: 0.7;
  }
  10%, 30% {
    opacity: 1;
    transform: scale(1.1);
  }
  20%, 40% {
    opacity: 0.8;
    transform: scale(1);
  }
}

/* グリッド背景（オプション） */
.heart-monitor::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    linear-gradient(rgba(0, 255, 157, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 255, 157, 0.05) 1px, transparent 1px);
  background-size: 20px 20px;
  border-radius: 20px;
  pointer-events: none;
}

/* レスポンシブ */
@media (max-width: 768px) {
  .heart-monitor {
    padding: 30px 20px;
  }

  .bpm-display {
    right: 20px;
    top: 15px;
  }

  .bpm-value {
    font-size: 2rem;
  }

  .bpm-label {
    font-size: 0.8rem;
  }

  #ecg-line {
    stroke-width: 2;
  }
}