/* ===========================
   study.css — Studyページ専用スタイル
   =========================== */

/* ===========================
   ページヘッダー
   =========================== */
.std-hero {
  padding: 110px 0 0;
  background: var(--color-bg);
}

.std-page-title {
  font-family: 'Cormorant Garamond', serif;
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--color-text);
  line-height: 1;
  margin-bottom: 20px;
}

/* ===========================
   タブナビ（スティッキー）
   =========================== */
.std-tab-wrap {
  position: sticky;
  top: 60px;
  z-index: 80;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.std-tab-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 10px 0;
}

.std-tab {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  padding: 6px 18px;
  transition: color var(--transition), border-color var(--transition), background var(--transition);
  position: relative;
  top: 1px;
}

.std-tab:hover,
.std-tab.is-active {
  color: var(--color-accent);
  border-color: var(--color-accent-border);
  background: var(--color-accent-pale);
}

/* ===========================
   各セクション共通
   =========================== */
.std-section {
  padding: 72px 0;
  border-bottom: 1px solid var(--color-border);
}

.std-section--alt {
  background: var(--color-bg-alt);
}

/* ===========================
   Log / reference / Club アイテム
   =========================== */
.std-item {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 48px;
  align-items: start;
}

.std-item-img-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 4 / 3;
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.std-section--alt .std-item-img-wrap {
  background: var(--color-bg);
}

.std-item-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.std-item-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: var(--color-text-muted);
  letter-spacing: 0.06em;
  pointer-events: none;
}

.std-item-img[src]:not([src=""])+.std-item-placeholder {
  display: none;
}

.std-item-body {
  padding-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.std-item-title {
  font-family: 'Cormorant Garamond', serif;
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: 0.02em;
  line-height: 1.2;
}

.std-item-text {
  font-size: 13.5px;
  color: var(--color-text-mid);
  line-height: 1.85;
}

.std-item-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  color: var(--color-accent);
  border: 1px solid var(--color-accent-border);
  border-radius: var(--radius-full);
  padding: 5px 14px;
  width: fit-content;
  transition: background var(--transition);
}

.std-item-link:hover {
  background: var(--color-accent-pale);
}

.std-item-link span {
  transition: transform var(--transition);
}

.std-item-link:hover span {
  transform: translateX(3px);
}

.std-club-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: flex-start;
}

/* ===========================
   trajectory タイムライン
   =========================== */
.std-traj-title {
  font-family: 'Cormorant Garamond', serif;
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 400;
  font-style: italic;
  color: var(--color-text);
  letter-spacing: 0.02em;
  margin-bottom: 40px;
}

.std-timeline {
  position: relative;
  padding-left: 32px;
}

/* 縦ライン */
.std-timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 0;
  width: 1px;
  background: var(--color-border);
}

.std-tl-item {
  position: relative;
  display: flex;
  gap: 24px;
  padding-bottom: 48px;
}

.std-tl-item:last-child {
  padding-bottom: 0;
}

/* 丸マーカー */
.std-tl-marker {
  position: absolute;
  left: -32px;
  top: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.std-tl-dot {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 2px solid var(--color-accent-border);
  background: var(--color-bg-alt);
  transition: border-color var(--transition), background var(--transition);
}

.std-tl-item:hover .std-tl-dot {
  border-color: var(--color-accent);
  background: var(--color-accent-pale);
}

.std-tl-body {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.std-tl-heading {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.5;
  letter-spacing: 0.02em;
}

.std-tl-text {
  font-size: 13px;
  color: var(--color-text-mid);
  line-height: 1.9;
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 640px) {
  .std-hero {
    padding: 90px 0 0;
  }

  .std-item {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .std-tab-nav {
    gap: 6px;
    overflow-x: auto;
    flex-wrap: nowrap;
    scrollbar-width: none;
  }

  .std-tab-nav::-webkit-scrollbar {
    display: none;
  }

  .std-tab {
    white-space: nowrap;
    font-size: 11px;
    padding: 5px 14px;
  }

  .std-timeline {
    padding-left: 24px;
  }

  .std-tl-marker {
    left: -24px;
  }
}

/* ===========================
   Community ロゴ表示
   =========================== */
#community .std-item-img-wrap {
  background: #000000;
}

#community .std-item-img {
  object-fit: contain;
  padding: 16px;
}

/* ===========================
   ヘッダーなし時：タブナビと最初のセクションの上余白
   =========================== */
.std-tab-wrap {
  padding-top: 48px;
}

#log {
  padding-top: 100px;
}