/**
 * サイトの使い方セクション - 美しいデザイン
 */

/* セクションコンテナ */
.how-to-use-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 24px;
  padding: 60px 20px;
  margin: 40px auto;
  max-width: 1200px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(102, 126, 234, 0.3);
}

/* 背景の装飾 */
.how-to-use-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 1px, transparent 1px);
  background-size: 50px 50px;
  animation: float-bg 20s linear infinite;
  opacity: 0.3;
}

@keyframes float-bg {
  0% { transform: translate(0, 0); }
  100% { transform: translate(50px, 50px); }
}

/* タイトル */
.how-to-title {
  text-align: center;
  color: white;
  font-size: clamp(28px, 5vw, 42px);
  font-weight: 900;
  margin-bottom: 20px;
  text-shadow: 0 4px 20px rgba(0,0,0,0.2);
  position: relative;
  z-index: 1;
}

.how-to-subtitle {
  text-align: center;
  color: rgba(255,255,255,0.9);
  font-size: clamp(16px, 3vw, 20px);
  margin-bottom: 50px;
  position: relative;
  z-index: 1;
}

/* ステップカードコンテナ */
.steps-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
  position: relative;
  z-index: 1;
}

/* ステップカード */
.step-card {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 20px;
  padding: 40px 30px;
  position: relative;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  cursor: pointer;
  overflow: hidden;
}

.step-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: linear-gradient(90deg, #ff6b9d, #feca57, #48dbfb);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.5s ease;
}

.step-card:hover::before {
  transform: scaleX(1);
}

.step-card:hover {
  transform: translateY(-10px) scale(1.02);
  box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

/* ステップ番号 */
.step-number {
  position: absolute;
  top: -15px;
  left: 30px;
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 24px;
  font-weight: bold;
  box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
  animation: pulse-number 2s ease-in-out infinite;
}

@keyframes pulse-number {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.1); }
}

/* ステップアイコン */
.step-icon {
  font-size: 64px;
  margin: 20px 0;
  display: block;
  text-align: center;
  animation: bounce-icon 3s ease-in-out infinite;
}

@keyframes bounce-icon {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* ステップタイトル */
.step-title {
  color: #2c3e50;
  font-size: 24px;
  font-weight: bold;
  margin-bottom: 15px;
  text-align: center;
}

/* ステップ説明 */
.step-description {
  color: #5a6c7d;
  font-size: 16px;
  line-height: 1.6;
  text-align: center;
  margin-bottom: 25px;
}

/* チェックリスト */
.step-checklist {
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  border-radius: 12px;
  padding: 20px;
  margin-top: 20px;
}

.checklist-item {
  background: white;
  border-radius: 8px;
  padding: 12px 15px;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.checklist-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  transform: scaleY(0);
  transition: transform 0.3s ease;
}

.checklist-item:hover::before {
  transform: scaleY(1);
}

.checklist-item:hover {
  transform: translateX(5px);
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

/* チェックボックス */
.checklist-checkbox {
  width: 24px;
  height: 24px;
  border: 3px solid #667eea;
  border-radius: 6px;
  position: relative;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.checklist-item.checked .checklist-checkbox {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-color: transparent;
}

.checklist-item.checked .checklist-checkbox::after {
  content: '✓';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: white;
  font-weight: bold;
  font-size: 16px;
}

.checklist-text {
  color: #4a5568;
  font-size: 15px;
  transition: all 0.3s ease;
}

.checklist-item.checked .checklist-text {
  text-decoration: line-through;
  opacity: 0.6;
}

/* 矢印アニメーション */
.step-arrow {
  text-align: center;
  font-size: 32px;
  color: white;
  margin: 20px 0;
  animation: arrow-bounce 1.5s ease-in-out infinite;
}

@keyframes arrow-bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(10px); }
}

/* プログレスバー */
.progress-container {
  margin-top: 40px;
  padding: 30px;
  background: rgba(255,255,255,0.1);
  border-radius: 16px;
  backdrop-filter: blur(10px);
}

.progress-title {
  color: white;
  font-size: 18px;
  font-weight: bold;
  margin-bottom: 15px;
  text-align: center;
}

.progress-bar {
  height: 12px;
  background: rgba(255,255,255,0.2);
  border-radius: 100px;
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #ff6b9d, #feca57, #48dbfb);
  border-radius: 100px;
  width: 0%;
  transition: width 1s ease;
  animation: progress-shine 2s linear infinite;
}

@keyframes progress-shine {
  0% { background-position: 0% 50%; }
  100% { background-position: 100% 50%; }
}

/* CTA ボタン */
.how-to-cta {
  text-align: center;
  margin-top: 50px;
  position: relative;
  z-index: 1;
}

.cta-button {
  display: inline-block;
  background: white;
  color: #667eea;
  padding: 20px 50px;
  border-radius: 100px;
  font-size: 20px;
  font-weight: bold;
  text-decoration: none;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.cta-button::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  transition: all 0.5s ease;
}

.cta-button:hover::before {
  width: 300px;
  height: 300px;
}

.cta-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 15px 40px rgba(0,0,0,0.3);
  color: white;
}

.cta-button span {
  position: relative;
  z-index: 1;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
  .how-to-use-section {
    padding: 40px 15px;
    margin: 20px 10px;
  }
  
  .steps-container {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .step-card {
    padding: 30px 20px;
  }
  
  .step-number {
    width: 50px;
    height: 50px;
    font-size: 20px;
  }
  
  .step-icon {
    font-size: 48px;
  }
  
  .step-title {
    font-size: 20px;
  }
  
  .cta-button {
    padding: 16px 40px;
    font-size: 18px;
    width: 90%;
    max-width: 300px;
  }
}

/* 完了アニメーション */
@keyframes complete-celebration {
  0% { transform: scale(1) rotate(0deg); }
  50% { transform: scale(1.2) rotate(180deg); }
  100% { transform: scale(1) rotate(360deg); }
}

.step-card.completed {
  background: linear-gradient(135deg, #84fab0 0%, #8fd3f4 100%);
}

.step-card.completed .step-number {
  animation: complete-celebration 1s ease;
  background: linear-gradient(135deg, #84fab0 0%, #8fd3f4 100%);
}

/* 光るエフェクト */
.glow-effect {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100px;
  height: 100px;
  background: radial-gradient(circle, rgba(255,255,255,0.8) 0%, transparent 70%);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
  opacity: 0;
  animation: glow-pulse 3s ease-in-out infinite;
}

@keyframes glow-pulse {
  0%, 100% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
  50% { opacity: 1; transform: translate(-50%, -50%) scale(1.5); }
}