/* モーダル背景（参考デザインのReady Screen風） */
.audio-modal {
  display: flex;
  position: fixed;
  z-index: 99999;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: #000;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.3s ease-in;
  pointer-events: auto !important;
}

.audio-modal.hidden {
  display: none;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* モーダルコンテンツ（ボタンのみ中央配置） */
.audio-modal-content {
  background: transparent;
  text-align: center;
  animation: slideUp 0.4s ease-out;
  pointer-events: auto !important;
  position: relative;
}

@keyframes slideUp {
  from { transform: translateY(30px); opacity: 0; }
  to   { transform: translateY(0);    opacity: 1; }
}

/* STARTボタンラッパー（リップル効果の基準） */
.start-btn-wrapper {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* リップルリング（参考デザインのripple-effect） */
.ripple-ring {
  position: absolute;
  inset: 0;
  border-radius: 100px;
  background: rgba(255, 255, 255, 0.25);
  animation: rippleOut 2s cubic-bezier(0, 0, 0.2, 1) infinite;
  pointer-events: none;
}

@keyframes rippleOut {
  0%   { transform: scale(1);   opacity: 0.6; }
  100% { transform: scale(2.2); opacity: 0;   }
}

/* STARTボタン（参考デザインの白ピル型） */
.start-btn {
  background: #ffffff;
  color: #000000;
  border: none;
  padding: 24px 80px;
  font-size: 28px;
  font-weight: 900;
  letter-spacing: 3px;
  border-radius: 100px;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 10px 40px rgba(255, 255, 255, 0.3);
  pointer-events: auto !important;
  position: relative;
  overflow: hidden;
  z-index: 999999;
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
  user-select: none;
}

.start-btn:active {
  transform: scale(0.95);
  box-shadow: 0 5px 20px rgba(255, 255, 255, 0.2);
}

/* 横向き対応 */
@media (orientation: landscape) {
  .start-btn {
    padding: 16px 50px;
    font-size: 20px;
    letter-spacing: 2px;
  }
}

@media (max-width: 480px) {
  .start-btn {
    padding: 20px 64px;
    font-size: 24px;
    letter-spacing: 2px;
  }
}