/* ===== 共通設定 ===== */
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  color: #333;
  line-height: 1.6;
}
img { max-width: 100%; height: auto; }
.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* ===== ヘッダー ===== */
.header { border-bottom: 1px solid #ddd; background: #fff; }
.header-inner {
  position: relative;
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.office-link {
  padding: 12px 24px;
  font-size: 1rem; font-weight: 700;
  background: #ffffff; color: #0B1C2D;
  border-radius: 999px; text-decoration: none;
  box-shadow: 0 5px 15px rgba(0,0,0,0.18);
  transition: all 0.3s ease; white-space: nowrap;
}
.office-link:hover { background: #2EC4F1; color: #fff; transform: scale(1.05); }

/* ===== スライドショー ===== */
.slider-section { padding: 32px 0; }
.slider { position: relative; height: 400px; overflow: hidden; border-radius: 6px; }
.slides img {
  position: absolute; width: 100%; height: 100%; object-fit: cover;
  opacity: 0; animation: fade-anim 25s infinite linear;
}
.slides img:nth-child(1) { animation-delay: 0s; }
.slides img:nth-child(2) { animation-delay: 5s; }
.slides img:nth-child(3) { animation-delay: 10s; }
.slides img:nth-child(4) { animation-delay: 15s; }
.slides img:nth-child(5) { animation-delay: 20s; }

@keyframes fade-anim {
  0% { opacity: 0; }
  5%, 20% { opacity: 1; }
  25%, 100% { opacity: 0; }
}

.overlay {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(11, 28, 45, 0.3); z-index: 5; pointer-events: none;
}

.slider-section-text {
  position: absolute; left: 8%; top: 50%; transform: translateY(-50%);
  color: #fff; z-index: 10; pointer-events: none;
}
.slider-section-text h1 {
  font-size: 3rem; line-height: 1.2; margin-bottom: 15px;
  text-shadow: 0 2px 10px rgba(0,0,0,0.3);
  animation: text-up 1.2s ease-out 0.5s forwards; opacity: 0;
}
.slider-section-text p {
  font-size: 1.2rem; animation: text-up 1.2s ease-out 0.8s forwards; opacity: 0;
}

@keyframes text-up {
  0% { opacity: 0; transform: translateY(20px); }
  100% { opacity: 1; transform: translateY(0); }
}

/* ===== インフラDX（折りたたみ） ===== */
.dx-section { background: #0B1C2D; color: #fff; padding: 40px 0; }
.dx-check { display: none; }
.dx-link { display: inline-block; margin-top: 15px; color: #2EC4F1; font-weight: 600; text-decoration: none; }

/* ===== イベント報告セクション ===== */
.event-section { background: #f7f9fb; padding: 60px 0; position: relative; overflow: hidden; }
.two-column { display: flex; gap: 32px; }
.column { flex: 1; }
.section-title { display: flex; align-items: center; gap: 12px; margin-bottom: 20px; }
.section-icon { width: 40px; opacity: 0.7; }
.cards-wrapper { max-height: 480px; overflow-y: auto; padding-right: 8px; }
.card { background: #fff; padding: 20px; margin-bottom: 16px; border-left: 4px solid #003A8F; }
.card.partner { border-left-color: #e39e00; }
.card.partner a { color: #e39e00 !important; }
.detail-link { font-size: 0.9rem; color: #003A8F; text-decoration: none; font-weight: 600; }

.event-character { position: absolute; right: 40px; bottom: 20px; width: 200px; opacity: 0.1; pointer-events: none; }

.footer { background: #eee; text-align: center; padding: 20px; font-size: 0.8rem; }

/* ===== レスポンシブ (スマホ) ===== */
@media (max-width: 768px) {
  .header-inner img { max-width: 50%; }
  .office-link { position: static; transform: none; font-size: 0.75rem; padding: 8px 12px; }
  
  .slider { height: 260px; }
  .slider-section-text h1 { font-size: 1.6rem; }
  
  /* スマホのみ折りたたみ有効 */
  .dx-hidden-content { max-height: 0; overflow: hidden; opacity: 0; transition: 0.5s ease; }
  .dx-check:checked + .dx-hidden-content { max-height: 600px; opacity: 1; margin-bottom: 15px; }
  .dx-more-btn { display: inline-block; color: #2EC4F1; cursor: pointer; padding: 10px 0; text-decoration: underline; font-weight: bold; }
  .dx-more-btn::before { content: "▼ もっと読む"; }
  .dx-check:checked ~ .dx-more-btn::before { content: "▲ 閉じる"; }

  .two-column { flex-direction: column; }
  .event-character { display: none; }
}

/* PCでは常に全表示 */
@media (min-width: 769px) {
  .dx-hidden-content { max-height: none !important; opacity: 1 !important; overflow: visible !important; }
  .dx-more-btn { display: none; }
}