.container {
  display: grid;
  grid-template-columns: auto 1fr;
  height: calc(100vh - var(--topbar-h));
  position: relative;
}

/* Prefer dynamic viewport on modern mobile browsers */
@supports (height: 100dvh) {
  .container { height: calc(100dvh - var(--topbar-h)); }
  .app { min-height: calc(100dvh - var(--topbar-h)); }
}
/* Fallback for older iOS Safari (uses JS-updated --app-vh) */
@supports not (height: 100dvh) {
  .container { height: calc((var(--app-vh, 1vh) * 100) - var(--topbar-h)); }
  .app { min-height: calc((var(--app-vh, 1vh) * 100) - var(--topbar-h)); }
}

.sidebar {
  border-right: 1px solid var(--separator);
  backdrop-filter: saturate(180%) blur(var(--blur-sm));
  -webkit-backdrop-filter: saturate(180%) blur(var(--blur-sm));
  background: var(--ios-group);
  padding: 12px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 12px;
  position: relative;
  width: var(--sidebar-w);
  transition: width .22s ease, padding .22s ease, background .2s ease, border-color .2s ease;
}

/* 折りたたみ時の安定した幅/余白（レイアウトの中途半端を排除） */
html[data-newui="on"][data-sidebar="collapsed"] .sidebar { width: 64px !important; padding: 12px 8px !important; }
html[data-newui="on"][data-sidebar="expanded"] .sidebar { width: var(--sidebar-w); }

/* 新UI: サイドバー折りたたみ（コンテナ基準） */
html[data-newui="on"] .container.sidebar-collapsed .sidebar { width: 64px; padding: 12px 8px; }
html[data-newui="on"] .container.sidebar-collapsed .sidebar .search-box,
html[data-newui="on"] .container.sidebar-collapsed .sidebar .grow,
html[data-newui="on"] .container.sidebar-collapsed .sidebar .meta {
  display: none;
}
html[data-newui="on"] .container.sidebar-collapsed .sidebar .chat-list .item { justify-content: center; }
html[data-newui="on"] .container.sidebar-collapsed .sidebar .chat-list .item .icon-btn { margin: 0 auto; }
/* 折りたたみ時のホバー挙動を抑制して上品に */
html[data-newui="on"] .container.sidebar-collapsed .sidebar .chat-list .item {
  transform: none !important;
}
html[data-newui="on"] .container.sidebar-collapsed .sidebar .chat-list .item:hover {
  background: rgba(255,255,255,0.65);
}
/* Simple Mode: サイドバー折りたたみ（新UI同等の挙動） */
html[data-simple="on"] .container.sidebar-collapsed .sidebar { width: 64px; padding: 12px 8px; }
html[data-simple="on"] .container.sidebar-collapsed .sidebar .search-box,
html[data-simple="on"] .container.sidebar-collapsed .sidebar .grow,
html[data-simple="on"] .container.sidebar-collapsed .sidebar .meta { display: none; }
html[data-simple="on"] .container.sidebar-collapsed .sidebar .chat-list .item { justify-content: center; transform: none !important; }
html[data-simple="on"] .container.sidebar-collapsed .sidebar .chat-list .item .icon-btn { margin: 0 auto; }
/* ツールチップ: タイトルをホバーで表示 */
html[data-newui="on"] .container.sidebar-collapsed .sidebar .chat-list .item {
  position: relative;
}
html[data-newui="on"] .container.sidebar-collapsed .sidebar .chat-list .item::after {
  content: attr(title);
  position: fixed;
  left: 72px;
  top: auto;
  transform: translateY(0);
  white-space: nowrap;
  background: var(--surface-strong);
  border: 1px solid var(--border);
  color: var(--text-1);
  padding: 6px 10px;
  border-radius: var(--radius-1);
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity .15s ease, transform .15s ease;
}
html[data-newui="on"] .container.sidebar-collapsed .sidebar .chat-list .item:hover::after {
  opacity: 1;
  transform: translateX(2px);
}
.sidebar-header { display: grid; gap: 8px; }
/* 折りたたみ時のヘッダー行の収まりを最適化 */
html[data-newui="on"] .container.sidebar-collapsed .sidebar-header { grid-template-columns: 1fr; }
html[data-newui="on"] .container.sidebar-collapsed #toggleSidebarBtn { width: 40px; height: 40px; display: grid; place-items: center; }
html[data-newui="on"] .container.sidebar-collapsed #newChatBtn { display: none; }
.search-box input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--separator);
  border-radius: var(--radius-2);
  background: var(--ios-card);
}
.chat-list { overflow: auto; padding-right: 6px; background: var(--ios-card); border: 1px solid var(--separator-weak); border-radius: var(--radius-3); padding: 6px; box-shadow: var(--shadow-sm); }
.cl-group-header { font-size: 12px; font-weight: 700; opacity: .65; padding: 10px 8px 4px; letter-spacing: .4px; text-transform: uppercase; }
.chat-list .item {
  display: flex; align-items: center; gap: 10px;
  padding: 10px;
  border-radius: var(--radius-2);
  cursor: pointer;
  transition: transform var(--dur) var(--ease-smooth), background var(--dur) var(--ease-smooth);
  position: relative;
  overflow: hidden;
}
.chat-list .item + .item { border-top: 1px solid var(--separator-weak); border-radius: 0; }
html[data-density="compact"] .chat-list .item { padding: 8px; gap: 8px; }
html[data-density="compact"] .sidebar { padding: 10px; }

.chat-list .item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 3px;
  height: 100%;
  background: var(--brand);
  transform: scaleY(0);
  transition: transform 0.2s ease;
}

.chat-list .item:hover { background: rgba(255,255,255,0.8); transform: none; }

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

.chat-list .item.active { outline: 2px solid rgba(10,132,255,0.35); background: white; transform: none; }
html[data-theme="dark"] .chat-list .item:hover { background: rgba(28,30,48,0.6); }
html[data-theme="dark"] .chat-list .item.active { background: rgba(18,20,36,0.9); }

/* ===== Simple Mode: sidebar + list styling ===== */
html[data-simple="on"] .sidebar {
  background: #111419;
  border-right: 1px solid rgba(255,255,255,0.08);
  backdrop-filter: none;
}
html[data-simple="on"] .search-box input,
html[data-simple="on"] .chat-list .item,
html[data-simple="on"] .primary-btn,
html[data-simple="on"] .icon-btn {
  background: #1a1f26;
  border-color: rgba(255,255,255,0.08);
  box-shadow: none;
}
html[data-simple="on"] .chat-list .item:hover { background: #1f2430; transform: none; }
html[data-simple="on"] .chat-list .item.active { background: #222736; outline-color: rgba(124,58,237,0.5); transform: none; }

.chat-list .item.active::before {
  transform: scaleY(1);
}
.item .title { font-weight: 600; }
.item .meta { font-size: 12px; opacity: 0.6; }

/* サイドバー: アイテム操作（削除） */
.chat-list .item .tools {
  margin-left: auto;
  display: none;
  gap: 6px;
}
.chat-list .item:hover .tools { display: flex; }
.chat-list .item .delete-btn,
.chat-list .item .fav-btn,
.chat-list .item .proj-btn {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--surface-strong);
  border-radius: var(--radius-round);
  padding: 4px 8px;
  font-size: 12px;
  cursor: pointer;
}
.chat-list .item .delete-btn:hover,
.chat-list .item .fav-btn:hover,
.chat-list .item .proj-btn:hover { background: white; }

.app {
  display: grid;
  grid-template-rows: 1fr auto;
  min-height: calc(100vh - var(--topbar-h));
}
.messages {
  overflow: auto;
  padding: 16px 20px 12px;
}
/* Avoid background page scroll chaining on mobile */
.messages { overscroll-behavior-y: contain; -webkit-overflow-scrolling: touch; }

/* 新UI: 新着ピル */
html[data-newui="on"] .new-pill {
  position: sticky;
  bottom: 12px;
  margin: 8px auto;
  z-index: 5;
  padding: 6px 10px;
  background: var(--surface-strong);
  border: 1px solid var(--border);
  border-radius: var(--radius-round);
  font-size: 12px;
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: all .2s ease;
}
html[data-newui="on"] .new-pill:hover { transform: translateY(-1px); }

/* スクロールボタンの位置調整（コンポーザー高さに追従） */
@media (max-width: 860px) {
  .scroll-bottom {
    bottom: 88px;
  }
}
.composer {
  display: flex;
  gap: 12px;
  align-items: center;
  border-top: 1px solid var(--separator);
  background: var(--ios-group);
  backdrop-filter: saturate(180%) blur(var(--blur-sm));
  -webkit-backdrop-filter: saturate(180%) blur(var(--blur-sm));
  padding: 12px 12px calc(12px + var(--safe-bottom));
}
html[data-density="compact"] .composer { gap: 8px; }
.composer .composer-menu-wrap { position: relative; display: grid; align-items: center; }
/* Plus button: match hero search button styling */
.composer .composer-menu-wrap > #composerPlus {
  width: 44px; height: 44px;
  display: grid; place-items: center;
  font-size: 20px;
  border: 1px solid var(--separator);
  background: var(--ios-card);
  border-radius: 12px;
  box-shadow: var(--shadow);
  transition: transform var(--dur) var(--ease-smooth), box-shadow var(--dur) var(--ease-smooth), background var(--dur) var(--ease-smooth);
}
.composer .composer-menu-wrap > #composerPlus:hover { transform: translateY(-1px); box-shadow: 0 12px 28px rgba(30,30,60,0.18); }
.composer .composer-menu-wrap > #composerPlus:active { transform: translateY(0); }
.composer .composer-menu-wrap .hero-menu { top: -216px; left: 0; }
.composer .composer-menu-wrap .submenu { left: 228px; top: 0; }
.composer .composer-attach-bar {
  display: none;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  margin: 0 0 8px;
}
.composer .composer-attach-bar[hidden] { display: none; }
.composer .composer-attach-bar:not([hidden]) { display: flex; }
.composer textarea {
  flex: 1;
  resize: none;
  border: 1px solid var(--separator);
  background: var(--ios-card);
  border-radius: var(--radius-round);
  padding: 12px 14px;
  line-height: 1.5;
  max-height: 200px;
  min-height: 44px;
  box-shadow: var(--shadow);
  transition: border-color var(--dur) var(--ease-smooth), box-shadow var(--dur) var(--ease-smooth), transform var(--dur) var(--ease-smooth);
}
/* Hero-like focus polish for composer textarea */
.composer textarea:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(107,107,255,0.10), 0 16px 48px rgba(30,30,60,0.18);
  outline: none;
  transform: translateY(-1px);
}
.composer-actions { display: flex; gap: 8px; align-items: center; }

/* モバイル時はフッターを浮遊させる */
@media (max-width: 860px) {
  .composer {
    position: sticky;
    bottom: 0;
    z-index: 10;
  }
}

/* 空状態 */
.empty-state {
  display: grid;
  place-items: center;
  text-align: center;
  gap: 12px;
  /* ヘッダ下からやや下に配置（上に寄り過ぎないように） */
  min-height: calc(100vh - var(--topbar-h));
  padding-top: 16vh;
  padding-bottom: 8vh;
}
.empty-state h1 {
  font-size: var(--fz-display);
  margin: 8px 0;
  font-weight: 900;
  letter-spacing: 0.2px;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.empty-state p { opacity: 0.75; margin: 0 0 8px; color: var(--text-muted); }

/* 検索バー風ヒーロー入力 */
.hero-input {
  display: grid;
  grid-template-columns: 44px 1fr 40px 44px;
  align-items: center;
  gap: 8px;
  width: min(760px, 88%);
  padding: 8px;
  border-radius: 999px;
  background: var(--ios-card);
  border: 1px solid var(--separator);
  box-shadow: 0 12px 40px rgba(30,30,60,0.15);
  backdrop-filter: blur(12px);
  position: relative; /* 添付プレビューを重ねるための基準 */
}
.hero-input:focus-within {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(107,107,255,0.1), 0 16px 48px rgba(30,30,60,0.18);
  transform: translateY(-1px);
}
.attach-preview {
  display: flex; gap: 8px; align-items: center; 
  position: absolute; 
  left: 64px; 
  top: 8px; 
  z-index: 1;
}
.hero-input:has(.attach-preview:not([hidden])) input { padding-left: 76px; }
.hero-input .attach-chip { width: 32px; height: 32px; border-radius: 8px; }
.attach-chip { position: relative; width: 64px; height: 64px; border-radius: 12px; overflow: hidden; box-shadow: var(--shadow); border: 1px solid var(--border); background: linear-gradient(135deg, #f3e8ff, #e9d5ff); }
.attach-chip img, .attach-chip .pdf { width: 100%; height: 100%; object-fit: cover; display: block; }
.attach-chip .tools { position: absolute; top: 6px; right: 6px; display: flex; gap: 6px; }
.attach-chip .tools button { width: 22px; height: 22px; border-radius: 999px; border: none; background: black; color: white; font-size: 12px; cursor: pointer; }
.attach-chip .tools button:hover { transform: scale(1.05); }
.hero-menu-wrap { position: relative; }
.hero-menu,
.submenu {
  position: absolute;
  top: 48px;
  left: 0;
  z-index: 20;
  min-width: 220px;
  display: grid;
  gap: 4px;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: linear-gradient(180deg, rgba(255,255,255,0.96), rgba(255,255,255,0.88));
  box-shadow: 0 18px 50px rgba(30,30,60,0.18), var(--shadow);
  backdrop-filter: blur(10px) saturate(140%);
}
html[data-theme="dark"] .hero-menu,
html[data-theme="dark"] .submenu {
  background: linear-gradient(180deg, rgba(20,20,35,0.94), rgba(20,20,35,0.88));
  box-shadow: 0 18px 50px rgba(0,0,0,0.55), var(--shadow);
}
/* Subtle sheen */
.hero-menu::before, .submenu::before {
  content: '';
  position: absolute; inset: 0;
  border-radius: inherit;
  background: linear-gradient(120deg, rgba(255,255,255,0.35), rgba(255,255,255,0.0));
  pointer-events: none;
}
.submenu { left: 228px; top: 0; }
.menu-item, .sub-item {
  appearance: none;
  border: 1px solid var(--separator-weak);
  border-radius: 12px;
  background: linear-gradient(180deg, rgba(255,255,255,0.95), rgba(248,249,255,0.92));
  text-align: left;
  padding: 12px 14px;
  cursor: pointer;
  font-weight: 600;
  letter-spacing: .2px;
  box-shadow: 0 6px 16px rgba(30,30,60,0.08);
  transition: transform var(--dur) var(--ease-smooth), box-shadow var(--dur) var(--ease-smooth), background var(--dur) var(--ease-smooth);
}
.menu-item:hover, .sub-item:hover {
  background: #f3f6ff;
  transform: translateY(-1px);
  box-shadow: 0 10px 24px rgba(30,30,60,0.14);
  outline: 1px solid color-mix(in oklab, var(--brand) 35%, transparent);
}
.menu-sep { height: 1px; background: linear-gradient(90deg, transparent, var(--border), transparent); margin: 6px 2px; border-radius: 1px; }
.menu-item.has-sub { display: flex; justify-content: space-between; align-items: center; }
html[data-theme="dark"] .menu-item, html[data-theme="dark"] .sub-item { background: rgba(255,255,255,0.06); color: #e6eaff; }
html[data-theme="dark"] .menu-item:hover, html[data-theme="dark"] .sub-item:hover { background: rgba(255,255,255,0.12); }
.hero-input input {
  width: 100%;
  height: 44px;
  border: none;
  border-radius: 999px;
  padding: 0 8px;
  font-size: 15px;
  background: transparent;
}
.hero-input input:focus { outline: none; }

.hero-input .sb-btn {
  appearance: none;
  border: 1px solid var(--separator);
  background: var(--ios-card);
  border-radius: 12px;
  width: 44px; height: 44px;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform .15s ease, box-shadow .2s ease;
}
.hero-input .sb-btn:hover { transform: translateY(-1px); }

.hero-input .sb-icon {
  appearance: none;
  border: 1px solid var(--separator);
  background: var(--ios-card);
  border-radius: 10px;
  width: 40px; height: 40px;
  display: grid; place-items: center;
  cursor: pointer;
}

.hero-input .sb-send {
  appearance: none;
  border: none;
  border-radius: 12px;
  width: 44px; height: 44px;
  display: grid; place-items: center;
  background: var(--grad-brand);
  color: white;
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: transform .15s ease;
}
.hero-input .sb-send:hover { transform: translateY(-1px); }
/* Unify composer action buttons with hero style */
.composer .icon-btn {
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border: 1px solid var(--separator);
  background: var(--ios-card);
  border-radius: 10px;
  box-shadow: var(--shadow);
}
.composer .send-btn {
  width: 44px; height: 44px; border-radius: 12px;
}

/* Simple Mode hero: flatter search bar */
html[data-simple="on"] .empty-state { padding-top: 18vh; }
html[data-simple="on"] .empty-state h1 { color: #e5e7eb; -webkit-text-fill-color: unset; background: none; font-weight: 800; }
html[data-simple="on"] .empty-state p { display: none; }
html[data-simple="on"] .hero-input { background: #1a1f26; border: 1px solid rgba(255,255,255,0.08); box-shadow: none; backdrop-filter: none; }
html[data-simple="on"] .hero-input:focus-within { box-shadow: 0 0 0 2px rgba(124,58,237,0.25); border-color: rgba(124,58,237,0.5); transform: none; }
html[data-simple="on"] .hero-input .sb-btn,
html[data-simple="on"] .hero-input .sb-icon { background: #1f2430; border-color: rgba(255,255,255,0.08); box-shadow: none; }
html[data-simple="on"] .hero-input .sb-send { box-shadow: none; }
/* Simple mode parity for composer controls */
html[data-simple="on"] .composer .icon-btn,
html[data-simple="on"] .composer #composerPlus { background: #1f2430; border-color: rgba(255,255,255,0.08); box-shadow: none; }
html[data-simple="on"] .composer textarea { box-shadow: none; }
html[data-simple="on"] .hero-menu, html[data-simple="on"] .submenu { background: var(--simple-surface); border: 1px solid var(--simple-border); box-shadow: none; }
html[data-simple="on"] .menu-item, html[data-simple="on"] .sub-item { background: var(--simple-surface-hover); border-color: var(--simple-border); box-shadow: none; }

/* モデルセクション（サイドバー内） */
/* サイドバーのモデルセクションはトップバー移設のため削除 */

/* サイドバー下部固定のフッター（設定ボタン） */
.sidebar-footer {
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* プロフィール（サイドバー下部） */
.user-profile {
  display: flex;
  align-items: center;
  gap: 10px;
}
html[data-density="compact"] .user-profile { gap: 8px; }
.avatar-wrap { position: relative; width: 32px; height: 32px; }
.avatar-wrap img { width: 32px; height: 32px; border-radius: 50%; object-fit: cover; border: 1px solid var(--border); display: none; }
.avatar-fallback { width: 32px; height: 32px; border-radius: 50%; display: grid; place-items: center; background: linear-gradient(120deg, var(--brand), var(--accent)); color: #fff; font-weight: 700; }
.user-meta { display: flex; flex-direction: column; gap: 2px; }
.user-meta .user-name { font-weight: 600; font-size: 13px; }

/* メッセージ幅のセンタリング向上 */
.messages {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.messages > * { width: min(var(--message-width, 780px), 92%); }
.messages.dragover::after {
  content: 'ファイルをドロップして添付';
  position: fixed;
  inset: 0;
  display: grid; place-items: center;
  background: rgba(30,30,60,0.25);
  color: white;
  font-weight: 700; letter-spacing: .5px;
  z-index: 30;
}

@media (max-width: 860px) {
  .container { grid-template-columns: 1fr; }
  .sidebar { display: none; }
}

/* Mobile sidebar drawer */
@media (max-width: 860px) {
  html[data-mobile-sidebar="open"] .sidebar {
    display: block;
    position: fixed;
    top: var(--topbar-h);
    bottom: 0;
    left: 0;
    width: min(88vw, 340px);
    z-index: 110;
    box-shadow: 0 20px 60px rgba(0,0,0,0.35);
    overflow: auto;
  }
  .mobile-backdrop { display: none; }
  html[data-mobile-sidebar="open"] .mobile-backdrop {
    display: block;
    position: fixed;
    top: var(--topbar-h);
    left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.35);
    backdrop-filter: blur(2px);
    z-index: 100;
  }
}

/* Mobile-first polish */
@media (max-width: 640px) {
  /* Prevent iOS zoom on focus */
  input, select, textarea { font-size: 16px; }

  /* Tighten hero input controls on very small screens */
  .hero-input { grid-template-columns: 44px 1fr 44px; }
  #heroMic { display: none; }

  /* Keep tap targets accessible */
  .icon-btn, .primary-btn { min-width: 44px; min-height: 44px; }
}