.bubble {
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: 10px;
  padding: 10px 6px;
}
/* 自分のメッセージは右寄せ配置（視認性向上） */
.bubble.user { grid-template-columns: 1fr 32px; }
.bubble.user .avatar { order: 2; }
.bubble.user .bubble-main { order: 1; }
.bubble.user .actions { justify-content: flex-end; }
/* hidden 属性の強制非表示（ブラウザ差異対策） */
[hidden] { display: none !important; }
/* Skip Link */
.skip-link {
  position: absolute;
  left: -9999px;
  top: -9999px;
  background: #111827;
  color: #fff;
  padding: 8px 12px;
  border-radius: 8px;
  z-index: 10000;
}
.skip-link:focus {
  left: 12px;
  top: 12px;
  outline: none;
  box-shadow: var(--focus-ring);
}
.avatar {
  width: 32px; height: 32px; border-radius: 50%;
  background: linear-gradient(120deg, var(--brand), var(--accent));
  color: white;
  display: grid; place-items: center;
  font-size: 14px; font-weight: 700;
}
.avatar.user { background: #111827; }
.content {
  background: linear-gradient(180deg, rgba(255,255,255,0.94), rgba(255,255,255,0.86));
  border: 1px solid var(--border);
  border-radius: var(--radius-3);
  padding: 12px 14px;
  box-shadow: var(--shadow);
  transition: background var(--dur) var(--ease-smooth), border-color var(--dur) var(--ease-smooth), box-shadow var(--dur) var(--ease-smooth);
  position: relative;
}
.bubble .meta { font-size: 12px; opacity: 0.55; margin-top: 6px; }
.bubble .meta .trust { display: inline-flex; align-items: center; gap: 6px; }
.bubble .meta .trust .model { font-weight: 600; opacity: 0.9; }
.bubble .meta .confidence { display: inline-flex; align-items: center; gap: 4px; padding: 2px 6px; border: 1px solid var(--border); border-radius: 999px; background: var(--surface); opacity: 0.85; }
.bubble .meta .confidence::before { content: '•'; color: var(--brand); font-weight: 700; }

/* Bubble actions: show on hover for cleaner look */
.bubble .actions { opacity: .0; transition: opacity var(--dur-fast) var(--ease-smooth), transform var(--dur-fast) var(--ease-smooth); }
.bubble:hover .actions { opacity: 1; }
/* Subtle lift on content hover */
.bubble .content:hover { transform: translateY(-1px); box-shadow: 0 14px 28px rgba(30,30,60,0.18), 0 6px 14px rgba(30,30,60,0.08); }

/* Focus-visible accessibility rings */
.icon-btn:focus-visible,
.primary-btn:focus-visible,
.secondary-btn:focus-visible,
input.toggle:focus-visible,
select.enhanced-select:focus-visible,
button:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px rgba(107, 107, 255, 0.24), 0 0 0 1px var(--brand);
}

.assistant .content { background: var(--surface-ultra); }
.user .content {
  background: linear-gradient(180deg, rgba(10,132,255,0.94), rgba(58,157,255,0.94));
  color: #fff;
  border-color: transparent;
}
.user .content a { color: #fff; text-decoration: underline; }
.user .markdown code { background: rgba(255,255,255,0.18); color: #fff; border-color: rgba(255,255,255,0.22); }

/* iMessage-like bubble tails */
.assistant .content::after {
  content: '';
  position: absolute;
  left: -6px;
  bottom: 10px;
  width: 12px;
  height: 12px;
  background: inherit;
  border-left: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  transform: rotate(45deg);
  border-bottom-left-radius: 2px;
}

.user .content::after {
  content: '';
  position: absolute;
  right: -6px;
  bottom: 10px;
  width: 12px;
  height: 12px;
  background: linear-gradient(180deg, rgba(10,132,255,0.96), rgba(58,157,255,0.96));
  transform: rotate(45deg);
}

.markdown p { margin: 0 0 8px; }
.markdown code {
  background: #f2f4ff; border: 1px solid var(--border);
  padding: 2px 6px; border-radius: 6px; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, 'Liberation Mono', monospace;
}
.markdown pre { overflow: auto; background: var(--code-bg); color: var(--code-fg); padding: 12px; border-radius: 8px; border: 1px solid var(--border); }
/* 長文/長単語の安全な折返し */
.markdown { overflow-wrap: anywhere; word-break: break-word; }
.markdown img, .markdown video, .markdown canvas, .markdown svg { max-width: 100%; height: auto; }

/* ドロップシャドウつきのモデルセレクタ下線アクセント */
.topbar .controls { position: relative; }
.topbar .controls::after {
  content: '';
  position: absolute; left: 0; right: 0; bottom: -6px; height: 3px;
  background: var(--grad-brand);
  border-radius: 99px;
  filter: blur(2px); opacity: 0.35;
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0;
}

/* モーダル */
.modal.hidden { display: none; }
.modal {
  position: fixed; inset: 0; display: grid; place-items: center; 
  background: rgba(10,10,20,0.35); backdrop-filter: blur(2px); z-index: 50;
  transition: all 0.2s ease;
}
.modal.opening {
  background: rgba(10,10,20,0.5);
}
.modal.closing {
  background: rgba(10,10,20,0.1);
}

.modal-content {
  width: min(720px, 92vw);
  background: white;
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
  transform: scale(0.9);
  transition: transform 0.2s ease;
}

.modal.opening .modal-content {
  transform: scale(1);
}

.modal.closing .modal-content {
  transform: scale(0.9);
}

/* Enhanced Modal Styles */
.enhanced-modal {
  width: min(800px, 95vw);
  box-shadow: 0 25px 75px rgba(30, 30, 60, 0.25), 0 10px 30px rgba(30, 30, 60, 0.15);
}

.enhanced-header {
  padding: 20px 24px;
  background: linear-gradient(135deg, rgba(248,249,255,0.95), rgba(255,255,255,0.9));
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-content {
  display: flex;
  align-items: center;
  gap: 16px;
}

.header-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  border-radius: var(--radius-2);
  display: grid;
  place-items: center;
  color: white;
  box-shadow: 0 8px 20px rgba(107, 107, 255, 0.3);
}

.header-text h2 {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
  color: var(--text-1);
}

.header-subtitle {
  margin: 4px 0 0;
  font-size: 14px;
  color: #6b7280;
  font-weight: 400;
}

.enhanced-close-btn {
  appearance: none;
  border: none;
  background: rgba(255,255,255,0.8);
  border-radius: var(--radius-1);
  padding: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  color: #6b7280;
  display: grid;
  place-items: center;
}

.enhanced-close-btn:hover {
  background: #fee2e2;
  color: #dc2626;
  transform: scale(1.1);
}

.enhanced-body {
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
  max-height: 70vh;
  overflow-y: auto;
}

/* Settings: Tabs Navigation */
.settings-tabs {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  gap: 8px;
  padding: 10px 12px;
  background: var(--ios-card);
  border-bottom: 1px solid var(--separator);
  backdrop-filter: blur(var(--blur-xs));
  overflow-x: auto;
}

/* Pro: Multi-model selector chips */
.pro-model-list { display: flex; flex-wrap: wrap; gap: 8px; }
.pro-model-list .pro-item { display: inline-flex; align-items: center; gap: 8px; padding: 8px 12px; border: 1px solid var(--separator); background: var(--surface-strong); border-radius: var(--radius-round); cursor: pointer; user-select: none; transition: background var(--dur) var(--ease-smooth), border-color var(--dur) var(--ease-smooth), box-shadow var(--dur) var(--ease-smooth); position: relative; }
.pro-model-list .pro-item input { accent-color: var(--brand); display: none; }
.pro-model-list .pro-item .pro-name { font-weight: 600; font-size: 13px; }
.pro-model-list .pro-item:hover { background: rgba(107,107,255,0.06); box-shadow: 0 6px 18px rgba(30,30,60,0.10); }
.pro-model-list .pro-item.selected { background: linear-gradient(135deg, rgba(107,107,255,0.10), rgba(159,84,255,0.10)); border-color: color-mix(in oklab, var(--brand) 40%, var(--separator)); box-shadow: 0 8px 22px rgba(107,107,255,0.12); }
.pro-model-list .pro-item.selected::before {
  content: '';
  position: absolute; inset: 0; border-radius: inherit;
  background: linear-gradient(90deg, transparent, rgba(107,107,255,0.18), transparent);
  mix-blend-mode: screen;
  animation: shimmer 1.8s linear infinite;
  opacity: .6;
}
.pro-model-list .pro-item.selected::after { content: '✓'; position: absolute; right: 10px; font-size: 12px; opacity: .8; color: var(--brand); }
html[data-theme="dark"] .pro-model-list .pro-item { background: rgba(20,20,35,0.65); border-color: rgba(255,255,255,0.1); }
html[data-theme="dark"] .pro-model-list .pro-item.selected { background: linear-gradient(135deg, rgba(60,60,120,0.35), rgba(120,60,140,0.35)); border-color: rgba(140,120,200,0.35); box-shadow: 0 8px 22px rgba(0,0,0,0.45); }

.settings-tabs .tab-btn {
  appearance: none;
  border: 1px solid var(--separator);
  background: rgba(255,255,255,0.7);
  color: var(--text-1);
  padding: 8px 12px;
  border-radius: var(--radius-round);
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  cursor: pointer;
  transition: all .15s var(--ease-smooth);
}

.settings-tabs .tab-btn:hover { transform: translateY(-1px); }
.settings-tabs .tab-btn[aria-selected="true"] { background: linear-gradient(135deg, var(--brand), var(--accent)); color: #fff; border-color: transparent; box-shadow: 0 6px 16px rgba(107,107,255,0.25); }

/* Tab panels: show only active (first visible before JS applies) */
.enhanced-body [role="tabpanel"] { display: none; }
.enhanced-body [role="tabpanel"].active { display: block; }
.enhanced-body [role="tabpanel"]:first-of-type { display: block; }

/* Settings Sections */
.settings-section {
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.settings-section:last-child {
  border-bottom: none;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px 24px 16px;
  background: linear-gradient(135deg, rgba(248,249,255,0.4), rgba(255,255,255,0.2));
}

.section-icon {
  font-size: 24px;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  background: rgba(255,255,255,0.8);
  border-radius: var(--radius-1);
  border: 1px solid var(--border);
}

.section-info h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  color: var(--text-1);
}

.section-info p {
  margin: 2px 0 0;
  font-size: 14px;
  color: #6b7280;
}

.section-content {
  padding: 0 24px 24px;
}

/* Enhanced Form Fields */
.enhanced-field {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.field-label {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.label-text {
  font-weight: 600;
  font-size: 14px;
  color: var(--text-1);
}

.label-description {
  font-size: 13px;
  color: #6b7280;
}

.custom-select-wrapper {
  position: relative;
  transition: all 0.2s ease;
}

.custom-select-wrapper.changed {
  transform: scale(1.02);
}

.enhanced-select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-2);
  background: linear-gradient(135deg, rgba(255,255,255,0.9), rgba(248,249,255,0.8));
  font-size: 14px;
  font-weight: 500;
  transition: all 0.2s ease;
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%236b7280'%3e%3cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3e%3c/path%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 40px;
}

.enhanced-select:focus {
  outline: none;
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(107, 107, 255, 0.1);
  background: white;
}

.range-wrapper {
  display: flex;
  align-items: center;
  gap: 16px;
}

.enhanced-range {
  flex: 1;
  height: 8px;
  border-radius: 4px;
  background: #e5e7eb;
  outline: none;
  appearance: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

.enhanced-range::-webkit-slider-thumb {
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(107, 107, 255, 0.3);
  transition: all 0.2s ease;
}

.enhanced-range::-webkit-slider-thumb:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 16px rgba(107, 107, 255, 0.4);
}

.enhanced-range::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  cursor: pointer;
  border: none;
  box-shadow: 0 4px 12px rgba(107, 107, 255, 0.3);
}

.range-value {
  background: linear-gradient(135deg, var(--brand), var(--accent));
  color: white;
  padding: 6px 12px;
  border-radius: var(--radius-round);
  font-weight: 600;
  font-size: 13px;
  min-width: 60px;
  text-align: center;
  box-shadow: 0 4px 12px rgba(107, 107, 255, 0.2);
}

/* Danger Section */
.danger-section .section-icon {
  background: linear-gradient(135deg, #fee2e2, #fecaca);
  color: #dc2626;
}

.danger-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
}

.enhanced-danger-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border: 1px solid #fecaca;
  background: linear-gradient(135deg, #fef2f2, #fee2e2);
  color: #dc2626;
  border-radius: var(--radius-2);
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

.enhanced-danger-btn:hover {
  background: linear-gradient(135deg, #fee2e2, #fecaca);
  border-color: #f87171;
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(220, 38, 38, 0.2);
}

.enhanced-danger-btn.critical {
  border-color: #dc2626;
  color: #991b1b;
}

.enhanced-danger-btn.critical:hover {
  background: linear-gradient(135deg, #fecaca, #f87171);
}

.enhanced-danger-btn.deleting {
  opacity: 0.6;
  transform: scale(0.98);
  pointer-events: none;
}

.enhanced-danger-btn.deleting::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.6), transparent);
  animation: shimmer 1s infinite;
}

@keyframes shimmer {
  0% { left: -100%; }
  100% { left: 100%; }
}

.warning-text {
  padding: 12px 16px;
  background: linear-gradient(135deg, #fffbeb, #fef3c7);
  border: 1px solid #fbbf24;
  border-radius: var(--radius-2);
  color: #92400e;
}

.warning-text p {
  margin: 0;
  font-size: 13px;
  font-weight: 500;
}

/* Enhanced Footer */
.enhanced-footer {
  padding: 20px 24px;
  background: linear-gradient(135deg, rgba(248,249,255,0.6), rgba(255,255,255,0.4));
  border-top: 1px solid var(--border);
}

.footer-actions {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

.secondary-btn {
  appearance: none;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.8);
  color: var(--text-1);
  padding: 10px 16px;
  border-radius: var(--radius-2);
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s ease;
}

.secondary-btn:hover {
  background: white;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(30, 30, 60, 0.1);
}

/* iOS-like toggle */
input.toggle {
  appearance: none;
  width: 46px;
  height: 28px;
  border-radius: 999px;
  background: #e5e7eb;
  border: 1px solid var(--separator);
  position: relative;
  box-shadow: inset 0 0 0 2px rgba(0,0,0,0.02);
  transition: background .2s ease, border-color .2s ease;
}
input.toggle::after {
  content: '';
  position: absolute;
  top: 2px; left: 2px;
  width: 22px; height: 22px;
  border-radius: 50%;
  background: white;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
  transition: transform .2s ease;
}
input.toggle:checked {
  background: linear-gradient(135deg, var(--brand), var(--accent));
  border-color: transparent;
}
input.toggle:checked::after {
  transform: translateX(18px);
}

.enhanced-save-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border: none;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  color: white;
  border-radius: var(--radius-2);
  cursor: pointer;
  font-weight: 600;
  transition: all 0.2s ease;
  box-shadow: 0 8px 20px rgba(107, 107, 255, 0.3);
  position: relative;
  overflow: hidden;
}

.enhanced-save-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 25px rgba(107, 107, 255, 0.4);
}

.enhanced-save-btn:disabled {
  opacity: 0.7;
  cursor: not-allowed;
  transform: none;
}

.enhanced-save-btn.saving::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  animation: shimmer 1s infinite;
}

/* Legacy Modal Styles */
.modal-header, .modal-footer { padding: 12px 16px; background: rgba(255,255,255,0.7); border-bottom: 1px solid var(--border); }
.modal-footer { border-top: 1px solid var(--border); border-bottom: none; }
.modal-body { padding: 16px; display: grid; gap: 12px; }
.field { display: grid; gap: 6px; }
.field.row { display: flex; gap: 8px; justify-content: space-between; }
.divider { height: 1px; background: var(--border); margin: 6px 0; }
.danger-btn { background: #fff0f0; border: 1px solid rgba(208,48,80,.25); color: #a1122f; padding: 10px 12px; border-radius: 10px; cursor: pointer; }
.danger-btn:hover { background: #ffe6e6; }


/* ————— ダークテーマ拡張 ————— */
html[data-theme="dark"] body {
  color: #e6eaff;
  background: #0b1020;
}
html[data-theme="dark"] .content { background: rgba(16,16,32,0.6); color: #e6eaff; border-color: rgba(255,255,255,0.08); }
html[data-theme="dark"] .sidebar,
html[data-theme="dark"] .composer,
html[data-theme="dark"] .topbar { 
  background: rgba(12,12,24,0.6);
  border-color: rgba(255,255,255,0.08);
}
html[data-theme="dark"] .primary-btn,
html[data-theme="dark"] .chip,
html[data-theme="dark"] .icon-btn,
html[data-theme="dark"] .plan-badge,
html[data-theme="dark"] .select-trigger,
html[data-theme="dark"] .search-input,
html[data-theme="dark"] .hero-input input,
html[data-theme="dark"] .composer textarea { 
  background: rgba(20,20,35,0.75);
  color: #e6eaff;
  border-color: rgba(255,255,255,0.1);
}
html[data-theme="dark"] .select-dropdown { background: rgba(16,16,28,0.96); border-color: rgba(255,255,255,0.08); }
html[data-theme="dark"] .group-header { background: linear-gradient(135deg, rgba(26,26,44,0.6), rgba(20,20,36,0.4)); }
html[data-theme="dark"] .dropdown-search { background: linear-gradient(135deg, rgba(26,26,44,0.95), rgba(20,20,36,0.8)); }
html[data-theme="dark"] .model-option:hover,
html[data-theme="dark"] .model-option.selected { background: linear-gradient(135deg, rgba(107, 107, 255, 0.08), rgba(159, 84, 255, 0.08)); }
html[data-theme="dark"] .modal-content { background: rgba(18,18,30,0.96); border-color: rgba(255,255,255,0.08); }
html[data-theme="dark"] .header-text h2 { color: #e6eaff; }
html[data-theme="dark"] .section-info h3 { color: #e6eaff; }
html[data-theme="dark"] .enhanced-close-btn { background: rgba(255,255,255,0.08); color: #c7d2fe; }
html[data-theme="dark"] .enhanced-close-btn:hover { background: rgba(239,68,68,0.2); color: #fecaca; }
html[data-theme="dark"] .secondary-btn { background: rgba(255,255,255,0.06); color: #e6eaff; }
html[data-theme="dark"] input.toggle { background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.12); }
html[data-theme="dark"] input.toggle::after { background: #0b1020; box-shadow: 0 2px 6px rgba(0,0,0,0.6); }
html[data-theme="dark"] .settings-tabs { background: linear-gradient(135deg, rgba(18,18,30,0.9), rgba(18,18,30,0.8)); border-bottom-color: rgba(255,255,255,0.08); }
html[data-theme="dark"] .settings-tabs .tab-btn { background: rgba(255,255,255,0.06); color: #e6eaff; border-color: rgba(255,255,255,0.12); }

/* ===== Simple Mode: calmer content surfaces ===== */
html[data-simple="on"] body { background: #111316; }
html[data-simple="on"] .content { background: #161a22; border-color: rgba(255,255,255,0.08); box-shadow: none; }
html[data-simple="on"] .assistant .content { background: #161a22; }
html[data-simple="on"] .user .content { background: #12161f; }
html[data-simple="on"] .topbar,
html[data-simple="on"] .sidebar,
html[data-simple="on"] .composer { box-shadow: none; }
html[data-simple="on"] .composer { background: #121419; border-top-color: rgba(255,255,255,0.08); backdrop-filter: none; }
html[data-simple="on"] .composer textarea { background: #1a1f26; border-color: rgba(255,255,255,0.08); box-shadow: none; }

/* 送信ボタンを上矢印のチップ風に最適化 */
.send-btn { font-size: 16px; line-height: 1; display: inline-grid; place-items: center; min-width: 44px; min-height: 40px; }

/* 文字数とスクロールボタン */
.char-count {
  font-size: 12px;
  color: #6b7280;
  min-width: 28px;
  text-align: right;
  padding: 0 4px;
}

.scroll-bottom {
  position: fixed;
  right: 20px;
  bottom: calc(20px + var(--composer-h) + env(safe-area-inset-bottom));
  appearance: none;
  border: 1px solid var(--border);
  background: var(--surface-strong);
  color: var(--text-1);
  border-radius: var(--radius-round);
  padding: 10px 12px;
  box-shadow: var(--shadow);
  cursor: pointer;
  opacity: 0;
  transform: translateY(6px);
  pointer-events: none;
  transition: all var(--dur) var(--ease-smooth);
  z-index: 20;
}

.scroll-bottom.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

/* Bookmark Bubble */
.bookmark-bubble {
  position: fixed;
  right: 20px;
  bottom: calc(76px + var(--composer-h) + env(safe-area-inset-bottom));
  appearance: none;
  border: 1px solid var(--border);
  background: var(--surface-strong);
  color: var(--text-1);
  border-radius: 999px;
  width: 44px; height: 44px;
  display: grid; place-items: center;
  box-shadow: var(--shadow);
  cursor: pointer;
  opacity: 0;
  transform: translateY(6px);
  pointer-events: none;
  transition: all var(--dur) var(--ease-smooth);
  z-index: 21;
}
.bookmark-bubble.show { opacity: 1; transform: translateY(0); pointer-events: auto; }
.bookmark-bubble.fav { background: linear-gradient(135deg, #fff7ed, #ffedd5); color: #b45309; border-color: #fed7aa; box-shadow: 0 6px 18px rgba(245,158,11,0.25); }

.send-btn.stop {
  background: linear-gradient(90deg, #ef4444, #dc2626);
}

/* バブル入場アニメーション */
.bubble.entering { animation: bubbleIn var(--dur) var(--ease-smooth); }
@keyframes bubbleIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

/* Phone-size optimizations */
@media (max-width: 420px) {
  /* Hide live counter to save space */
  .composer-actions #charCount { display: none; }
}

/* 録音インジケータと録音状態 */
.mic-indicator { display: inline-flex; align-items: center; gap: 8px; padding: 6px 10px; border-radius: var(--radius-round); border: 1px solid var(--border); background: var(--surface-strong); box-shadow: var(--shadow); }
.mic-indicator .dot { width: 8px; height: 8px; border-radius: 50%; background: #ef4444; box-shadow: 0 0 0 0 rgba(239,68,68,0.7); animation: pulse 1.2s infinite; }
.mic-indicator .bars { width: 10px; height: 12px; background: linear-gradient(180deg, rgba(239,68,68,0.2), rgba(239,68,68,0.6)); border-radius: 2px; animation: level 0.6s infinite ease-in-out; }
.mic-indicator .label { font-size: 12px; opacity: .75; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(239,68,68,0.7);} 70% { box-shadow: 0 0 0 6px rgba(239,68,68,0);} 100% { box-shadow: 0 0 0 0 rgba(239,68,68,0);} }
@keyframes level { 0%, 100% { height: 8px; } 50% { height: 16px; } }

/* 長文の折りたたみ（控えめなグラデーションフェード） */
.content.collapsible { position: relative; }
.content.collapsible.collapsed { max-height: 900px; overflow: hidden; }
.content.collapsible.collapsed::after {
  content: '';
  position: absolute; inset: 70% 0 0 0;
  background: linear-gradient(180deg, rgba(255,255,255,0), rgba(255,255,255,0.96));
}
html[data-theme="dark"] .content.collapsible.collapsed::after { background: linear-gradient(180deg, rgba(0,0,0,0), rgba(14,16,28,0.96)); }

/* 日付セパレータ */
.date-separator { display: grid; place-items: center; padding: 6px 0; }
.date-separator .pill { font-size: 12px; padding: 4px 10px; border: 1px solid var(--border); background: var(--surface-strong); border-radius: var(--radius-round); color: var(--text-muted); box-shadow: var(--shadow-sm); }

.icon-btn.recording { border-color: #ef4444; box-shadow: 0 0 0 3px rgba(239,68,68,0.15); }

/* 文字数警告 */
.char-count.warn { color: #dc2626; font-weight: 700; }
.char-count.warn::after { content: ' !'; }

/* ============ 新UI/UXトグル時の上書き ============ */
html[data-newui="on"] body {
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
}

html[data-newui="on"] .markdown pre,
html[data-newui="on"] .code-block pre {
  font-size: var(--font-size-code);
  line-height: var(--line-height-code);
}

html[data-newui="on"] .action-btn,
html[data-newui="on"] .char-count {
  font-size: var(--font-size-small);
  line-height: var(--line-height-small);
}

/* フォーカスリングの一貫化 */
html[data-newui="on"] .primary-btn:focus-visible,
html[data-newui="on"] .icon-btn:focus-visible,
html[data-newui="on"] .send-btn:focus-visible,
html[data-newui="on"] .chip:focus-visible,
html[data-newui="on"] .enhanced-select:focus-visible,
html[data-newui="on"] input:focus-visible,
html[data-newui="on"] textarea:focus-visible,
html[data-newui="on"] button:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-color: var(--focus-border);
}

/* マウスクリック時はフォーカスリングを抑制 */
html[data-newui="on"] .primary-btn:focus:not(:focus-visible),
html[data-newui="on"] .icon-btn:focus:not(:focus-visible),
html[data-newui="on"] .send-btn:focus:not(:focus-visible),
html[data-newui="on"] .chip:focus:not(:focus-visible),
html[data-newui="on"] .enhanced-select:focus:not(:focus-visible),
html[data-newui="on"] input:focus:not(:focus-visible),
html[data-newui="on"] textarea:focus:not(:focus-visible),
html[data-newui="on"] button:focus:not(:focus-visible) {
  box-shadow: none;
  border-color: inherit;
}

/* スクロールバー（控えめ） */
html[data-newui="on"] *::-webkit-scrollbar { width: 10px; height: 10px; }
html[data-newui="on"] *::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 8px; }
html[data-newui="on"] *::-webkit-scrollbar-thumb:hover { background: var(--scrollbar-thumb-hover); }
html[data-newui="on"] * { scrollbar-width: thin; scrollbar-color: var(--scrollbar-thumb) transparent; }

/* タイムスタンプ/メタの視認性 */
html[data-newui="on"] .bubble .meta { font-size: var(--font-size-meta); line-height: var(--line-height-meta); opacity: 0.65; }

/* メッセージのセパレータ（軽め） */
html[data-newui="on"] .bubble .content { box-shadow: var(--elev-1); }

/* 折りたたみ時のトップバー/背景の視覚的ズレを軽減 */
html[data-newui="on"][data-sidebar="collapsed"] .topbar { border-left: 1px solid var(--border); }

/* ===== スクロールシャドウ（メッセージ/サイドバー） ===== */
.messages { position: relative; }
.messages::before,
.messages::after {
  content: '';
  position: sticky;
  left: 0;
  right: 0;
  height: 16px;
  pointer-events: none;
  z-index: 2;
  display: none;
}
.messages.has-top-shadow::before { top: 0; display: block; background: linear-gradient(to bottom, rgba(0,0,0,0.08), transparent); }
.messages.has-bottom-shadow::after { bottom: 0; display: block; background: linear-gradient(to top, rgba(0,0,0,0.08), transparent); }

.chat-list { position: relative; }
.chat-list::before,
.chat-list::after {
  content: '';
  position: sticky;
  left: 0; right: 0;
  height: 12px;
  pointer-events: none;
  z-index: 2;
  display: none;
}
.chat-list.has-top-shadow::before { top: 0; display: block; background: linear-gradient(to bottom, rgba(0,0,0,0.06), transparent); }
.chat-list.has-bottom-shadow::after { bottom: 0; display: block; background: linear-gradient(to top, rgba(0,0,0,0.06), transparent); }

html[data-theme="dark"] .messages.has-top-shadow::before { background: linear-gradient(to bottom, rgba(255,255,255,0.12), transparent); }
html[data-theme="dark"] .messages.has-bottom-shadow::after { background: linear-gradient(to top, rgba(255,255,255,0.12), transparent); }
html[data-theme="dark"] .chat-list.has-top-shadow::before { background: linear-gradient(to bottom, rgba(255,255,255,0.08), transparent); }
html[data-theme="dark"] .chat-list.has-bottom-shadow::after { background: linear-gradient(to top, rgba(255,255,255,0.08), transparent); }

/* トップバーのスクロール時の影強化 */
.topbar.scrolled { box-shadow: 0 6px 18px rgba(30,30,60,0.12); }
html[data-theme="dark"] .topbar.scrolled { box-shadow: 0 6px 18px rgba(0,0,0,0.6); }

/* タップターゲット拡大（新UI） */
html[data-newui="on"] .icon-btn,
html[data-newui="on"] .action-btn { min-height: 40px; }

/* ダークテーマ: メタの視認性を向上 */
html[data-theme="dark"] .bubble .meta { opacity: 0.8; color: #c7d2fe; }

/* モデルセレクタ: フォーカス可視化と小画面対応 */
.model-option:focus-visible { outline: none; background: linear-gradient(135deg, rgba(107, 107, 255, 0.08), rgba(159, 84, 255, 0.08)); border-left-color: var(--brand); }
@media (max-height: 740px) { .select-dropdown { max-height: 60vh; } }

/* トーストのバリアント */
.toast.success { background: linear-gradient(135deg, rgba(16,185,129,0.9), rgba(16,185,129,0.85)); }
.toast.error { background: linear-gradient(135deg, rgba(239,68,68,0.9), rgba(239,68,68,0.85)); }
.toast.info { background: linear-gradient(135deg, rgba(59,130,246,0.9), rgba(59,130,246,0.85)); }

/* 低モーション設定への配慮 */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}

/* ===== GPT-5 thinking エフェクト（応答待ち・推論レベルに応じて変化） ===== */
.thinking-bubbles {
  --think-color-1: var(--brand);
  --think-color-2: var(--accent);
  --think-speed: 1.1s;
  --think-size: 9px;
  position: relative; display: inline-flex; gap: 8px; align-items: center; padding: 6px 10px; border-radius: 999px;
}
.thinking-bubbles::before {
  content: '';
  position: absolute; inset: 0; z-index: -1; border-radius: inherit;
  background: radial-gradient(120% 150% at 50% -20%, color-mix(in oklab, var(--think-color-2) 26%, transparent), transparent),
              radial-gradient(120% 150% at 50% 140%, color-mix(in oklab, var(--think-color-1) 26%, transparent), transparent);
  filter: blur(8px);
}
.thinking-bubbles::after {
  content: '';
  position: absolute; inset: 0;
  border-radius: inherit;
  background: linear-gradient(90deg, rgba(255,255,255,0.0), rgba(255,255,255,0.25), rgba(255,255,255,0.0));
  mix-blend-mode: screen;
  animation: tb-shimmer 2.2s linear infinite;
}
@keyframes tb-shimmer { 0% { transform: translateX(-100%);} 100% { transform: translateX(100%);} }
.thinking-bubbles .dot { width: var(--think-size); height: var(--think-size); border-radius: 50%; background: linear-gradient(135deg, var(--think-color-1), var(--think-color-2)); opacity: .95; animation: think var(--think-speed) infinite ease-in-out; box-shadow: 0 0 10px color-mix(in oklab, var(--think-color-1) 35%, transparent); }
/* 推論レベル別の色・モーション変化 */
.thinking-bubbles.effort-low { --think-color-1: hsl(210 90% 65%); --think-color-2: hsl(190 95% 60%); --think-speed: 1.35s; --think-size: 8px; }
.thinking-bubbles.effort-medium { --think-color-1: hsl(38 92% 62%); --think-color-2: hsl(160 70% 50%); --think-speed: 1.1s; --think-size: 9px; }
.thinking-bubbles.effort-high { --think-color-1: hsl(280 85% 65%); --think-color-2: hsl(320 88% 60%); --think-speed: 0.9s; --think-size: 10px; }
.thinking-bubbles .dot:nth-child(2) { animation-delay: .12s; }
.thinking-bubbles .dot:nth-child(3) { animation-delay: .24s; }
@keyframes think { 0%, 80%, 100% { transform: translateY(0) scale(1); } 40% { transform: translateY(-2px) scale(1.06); } }

/* 推論レベルバッジ */
.reasoning-badge { margin-left: 8px; padding: 2px 8px; border-radius: 999px; font-size: 11px; font-weight: 700; letter-spacing: .02em; color: #3b0764; background: linear-gradient(90deg, rgba(250,245,255,0.95), rgba(240,240,255,0.92)); border: 1px solid rgba(140,120,200,0.25); }
html[data-theme="dark"] .reasoning-badge { color: #f5f3ff; background: linear-gradient(90deg, rgba(60,40,100,0.55), rgba(46,48,90,0.55)); border-color: rgba(220,220,255,0.15); }

/* Asobi Achievements */
.achievements { display: flex; flex-wrap: wrap; gap: 8px; }
.achievement { display: inline-flex; align-items: center; gap: 6px; padding: 6px 10px; border: 1px solid var(--border); background: var(--surface-strong); border-radius: var(--radius-round); font-size: 12px; }
.achievement .emoji { font-size: 14px; }

/* Asobi: assistant badge */
.asobi-badge {
  display: inline-block;
  margin-top: 8px;
  padding: 6px 8px;
  font-size: 12px;
  border-radius: 10px;
  background: linear-gradient(90deg, rgba(255,237,213,0.9), rgba(255,243,224,0.9));
  border: 1px solid rgba(250,200,120,0.3);
  color: #92400e;
  font-weight: 700;
}

/* Asobi achievement pulse */
.achievement.pulse { animation: asobiPulse 1.2s ease-in-out 1; }
@keyframes asobiPulse { 0% { transform: scale(.98); } 50% { transform: scale(1.05); } 100% { transform: scale(1); } }

/* ===== Command Palette (Cmd/Ctrl + K) ===== */
.cmdk-overlay { position: fixed; inset: 0; background: rgba(10,10,20,0.4); backdrop-filter: blur(2px); display: none; align-items: flex-start; justify-content: center; padding-top: 12vh; z-index: 1000; }
.cmdk-overlay.open { display: flex; }
.cmdk { width: min(720px, 92vw); border: 1px solid var(--border); border-radius: 12px; background: var(--surface-strong); box-shadow: var(--shadow-lg); overflow: hidden; }
.cmdk-header { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border-bottom: 1px solid var(--border); background: linear-gradient(135deg, rgba(248,249,255,0.9), rgba(255,255,255,0.8)); }
.cmdk-input { flex: 1; border: none; background: transparent; font-size: 16px; padding: 8px 6px; }
.cmdk-input:focus { outline: none; }
.cmdk-body { max-height: 52vh; overflow: auto; padding: 6px; }
.cmdk-section { padding: 6px 6px 2px; font-size: 11px; font-weight: 700; opacity: .65; letter-spacing: .3px; text-transform: uppercase; }
.cmdk-item { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border-radius: 10px; cursor: pointer; transition: background .15s ease, transform .1s ease; }
.cmdk-item:hover, .cmdk-item[aria-selected="true"] { background: rgba(107,107,255,0.08); }
.cmdk-item .k { margin-left: auto; font-size: 11px; opacity: .6; }
.cmdk-empty { padding: 10px 12px; color: var(--text-muted); }
html[data-theme="dark"] .cmdk { background: rgba(18,18,34,0.95); }

/* ===== Density: Compact adjustments ===== */
html[data-density="compact"] .bubble { grid-template-columns: 28px 1fr; gap: 8px; padding: 8px 4px; }
html[data-density="compact"] .avatar { width: 28px; height: 28px; font-size: 12px; }
html[data-density="compact"] .content { padding: 10px 12px; }
html[data-density="compact"] .bubble .actions .action-btn { padding: 3px 8px; font-size: 11px; }
html[data-density="compact"] .composer { padding: 8px; }
html[data-density="compact"] .composer textarea { padding: 10px 12px; }
html[data-density="compact"] .secondary-btn, html[data-density="compact"] .primary-btn { padding: 8px 12px; }
html[data-density="compact"] .enhanced-save-btn { padding: 8px 16px; }

/* ===== High contrast tweaks for key surfaces ===== */
html[data-contrast="high"] .content,
html[data-contrast="high"] .composer textarea,
html[data-contrast="high"] .enhanced-select,
html[data-contrast="high"] .search-input { border-width: 2px; }
html[data-contrast="high"] .primary-btn,
html[data-contrast="high"] .icon-btn,
html[data-contrast="high"] .chip { border-width: 2px; }
html[data-contrast="high"] .topbar { border-bottom-width: 2px; }