:root {
  /* Apple Warm Cashmere & Ivory Light Theme (Default) */
  --bg-canvas: #FAF6F0;
  --bg-sidebar: rgba(242, 236, 226, 0.78);
  --bg-topbar: rgba(250, 246, 240, 0.78);
  --bg-card: #FFFFFF;
  --bg-elevated: #F4EFE6;
  --bg-hover: rgba(65, 48, 30, 0.05);
  --bg-active: #FFFFFF;
  --bg-user-bubble: linear-gradient(145deg, #C86D51 0%, #B75D41 100%);
  --bg-code: #F6F2EB;

  --text-primary: #1F1C18;
  --text-secondary: #6E665E;
  --text-tertiary: #9C9288;
  --text-on-accent: #FFFFFF;

  --accent: #C66B4E;
  --accent-hover: #B35A3E;
  --accent-soft: rgba(198, 107, 78, 0.12);
  --accent-gold: #D49B4B;
  --danger: #D94E4E;
  --success: #3E8E63;

  --border-subtle: rgba(55, 42, 28, 0.085);
  --border-strong: rgba(55, 42, 28, 0.15);

  --shadow-sm: 0 2px 8px rgba(45, 32, 20, 0.04), 0 1px 2px rgba(45, 32, 20, 0.03);
  --shadow-md: 0 8px 28px -4px rgba(45, 32, 20, 0.07), 0 2px 6px rgba(45, 32, 20, 0.04);
  --shadow-lg: 0 20px 48px -8px rgba(45, 32, 20, 0.14), 0 4px 12px rgba(45, 32, 20, 0.06);

  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 999px;
}

[data-theme="dark"] {
  /* Apple Warm Espresso Dark Theme */
  --bg-canvas: #171513;
  --bg-sidebar: rgba(32, 29, 26, 0.82);
  --bg-topbar: rgba(23, 21, 19, 0.80);
  --bg-card: #221F1C;
  --bg-elevated: #2B2723;
  --bg-hover: rgba(255, 245, 235, 0.06);
  --bg-active: #302B27;
  --bg-user-bubble: linear-gradient(145deg, #C86D51 0%, #AD553A 100%);
  --bg-code: #1B1816;

  --text-primary: #F5F0EA;
  --text-secondary: #ABA299;
  --text-tertiary: #787067;

  --accent: #D67A5C;
  --accent-hover: #E0886B;
  --accent-soft: rgba(214, 122, 92, 0.18);

  --border-subtle: rgba(255, 245, 235, 0.08);
  --border-strong: rgba(255, 245, 235, 0.16);

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.55);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg-canvas);
  color: var(--text-primary);
  height: 100dvh;
  display: flex;
  overflow: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

/* ==================== Apple Frosted Lock Screen (Login) ==================== */
.login-screen {
  position: fixed;
  inset: 0;
  z-index: 100;
  background:
    radial-gradient(circle at 20% 20%, rgba(212, 155, 75, 0.14), transparent 48%),
    radial-gradient(circle at 80% 75%, rgba(198, 107, 78, 0.16), transparent 52%),
    var(--bg-canvas);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.login-screen.hidden {
  display: none;
}

.login-card {
  width: 100%;
  max-width: 380px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 26px;
  padding: 36px 30px 32px;
  box-shadow: var(--shadow-lg);
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.login-brand-icon {
  width: 60px;
  height: 60px;
  margin: 0 auto;
  border-radius: 18px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  font-size: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-sm);
}

.login-title {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.login-subtitle {
  font-size: 13.5px;
  color: var(--text-secondary);
  margin-top: -10px;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  text-align: left;
  margin-top: 4px;
}

.apple-input {
  width: 100%;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  padding: 11px 14px;
  border-radius: 12px;
  font-size: 14px;
  outline: none;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
  font-family: inherit;
}

.apple-input:focus {
  background: var(--bg-card);
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.login-error {
  font-size: 12.5px;
  color: var(--danger);
  text-align: center;
  min-height: 18px;
}

/* ==================== Sidebar ==================== */
.sidebar {
  width: 272px;
  background: var(--bg-sidebar);
  backdrop-filter: blur(28px) saturate(180%);
  -webkit-backdrop-filter: blur(28px) saturate(180%);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  z-index: 30;
  transition: transform 0.28s cubic-bezier(0.25, 1, 0.5, 1);
}

.sidebar-header {
  padding: 18px 16px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.brand-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 15.5px;
  letter-spacing: -0.01em;
}

.brand-dot {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  box-shadow: var(--shadow-sm);
}

.btn {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 7px 12px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  box-shadow: var(--shadow-sm);
  transition: all 0.16s ease;
  text-decoration: none;
  user-select: none;
  white-space: nowrap;
}

.btn:hover {
  background: var(--bg-elevated);
  border-color: var(--border-strong);
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--bg-user-bubble);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 4px 12px rgba(198, 107, 78, 0.25);
}

.btn-primary:hover {
  opacity: 0.94;
  background: var(--bg-user-bubble);
}

.btn-ghost {
  background: transparent;
  border-color: transparent;
  box-shadow: none;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
  border-color: transparent;
}

.new-chat-wrap {
  padding: 0 14px 10px;
}

.new-chat-btn {
  width: 100%;
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 13.5px;
  justify-content: flex-start;
}

.session-list {
  flex: 1;
  overflow-y: auto;
  padding: 6px 10px 14px;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.session-item {
  padding: 9px 12px;
  border-radius: 11px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13.5px;
  color: var(--text-secondary);
  transition: all 0.15s ease;
}

.session-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.session-item.active {
  background: var(--bg-active);
  color: var(--text-primary);
  font-weight: 500;
  box-shadow: var(--shadow-sm);
}

.session-item-left {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
  flex: 1;
}

.session-mode-tag {
  font-size: 11px;
  padding: 1px 6px;
  border-radius: 6px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
  flex-shrink: 0;
}

.session-title {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

.session-del {
  opacity: 0;
  background: none;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  font-size: 13px;
  padding: 2px 6px;
  border-radius: 6px;
}

.session-item:hover .session-del {
  opacity: 1;
}

.session-del:hover {
  color: var(--danger);
  background: rgba(217, 78, 78, 0.1);
}

.sidebar-footer {
  padding: 12px 14px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.user-chip {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 6px 10px;
  border-radius: 12px;
  cursor: pointer;
  flex: 1;
  min-width: 0;
  transition: background 0.15s;
}

.user-chip:hover {
  background: var(--bg-hover);
}

.user-chip-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  box-shadow: var(--shadow-sm);
}

.user-chip-info {
  min-width: 0;
  flex: 1;
}

.user-chip-name {
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-chip-status {
  font-size: 11px;
  color: var(--success);
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ==================== Main Area & Apple Topbar ==================== */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100dvh;
}

.topbar {
  min-height: 56px;
  padding: 8px 18px;
  background: var(--bg-topbar);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  z-index: 15;
}

.topbar-left, .topbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.menu-toggle {
  display: none;
}

/* Apple UISegmentedControl */
.segmented-control {
  background: var(--bg-elevated);
  padding: 3px;
  border-radius: 11px;
  display: inline-flex;
  border: 1px solid var(--border-subtle);
}

.seg-btn {
  border: none;
  background: transparent;
  color: var(--text-secondary);
  padding: 5px 13px;
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.18s ease;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.seg-btn.active {
  background: var(--bg-card);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
  font-weight: 600;
}

/* Arena Multi-Model Picker Bar */
.arena-picker-bar {
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border-subtle);
  padding: 10px 18px;
  display: none;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.arena-picker-bar.visible {
  display: flex;
}

.arena-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-right: 4px;
}

.arena-model-chip {
  padding: 5px 11px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 500;
  background: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: all 0.15s ease;
  user-select: none;
}

.arena-model-chip:hover {
  border-color: var(--accent);
}

.arena-model-chip.selected {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: var(--accent);
  font-weight: 600;
}

/* ==================== Messages Area ==================== */
.messages {
  flex: 1;
  overflow-y: auto;
  padding: 28px 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.msg-turn {
  max-width: 880px;
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.msg-turn.arena-turn {
  max-width: 1260px;
}

.user-row {
  display: flex;
  justify-content: flex-end;
}

.user-bubble {
  background: var(--bg-user-bubble);
  color: var(--text-on-accent);
  padding: 12px 17px;
  border-radius: 20px 20px 5px 20px;
  font-size: 14.5px;
  line-height: 1.6;
  max-width: 82%;
  box-shadow: 0 4px 14px rgba(198, 107, 78, 0.2);
  white-space: pre-wrap;
  word-break: break-word;
}

.attached-images {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.attached-img {
  max-width: 220px;
  max-height: 180px;
  border-radius: 12px;
  object-fit: cover;
  border: 1px solid rgba(255,255,255,0.25);
  cursor: zoom-in;
}

.attached-files {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.msg-file-pill {
  background: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.28);
  padding: 5px 10px;
  border-radius: 9px;
  font-size: 12.5px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Assistant Single & Arena Grid */
.responses-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  width: 100%;
}

.responses-grid.cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.responses-grid.cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.responses-grid.cols-4 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.ai-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 16px 18px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.ai-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 12.5px;
}

.ai-model-badge {
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.ai-model-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

.ai-effort-tag {
  font-size: 11px;
  padding: 1px 6px;
  border-radius: 6px;
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font-weight: 500;
}

.ai-elapsed {
  font-size: 11.5px;
  color: var(--text-tertiary);
  font-variant-numeric: tabular-nums;
}

.think-box {
  background: var(--bg-elevated);
  border-left: 3px solid var(--accent-gold);
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 12.5px;
  color: var(--text-secondary);
}

.think-box summary {
  cursor: pointer;
  font-weight: 500;
  user-select: none;
}

.think-content {
  margin-top: 6px;
  white-space: pre-wrap;
  line-height: 1.55;
}

/* Markdown Styling */
.md-body {
  font-size: 14.5px;
  line-height: 1.68;
  color: var(--text-primary);
  overflow-x: auto;
  word-break: break-word;
}

.md-body p { margin-bottom: 10px; }
.md-body p:last-child { margin-bottom: 0; }
.md-body h1, .md-body h2, .md-body h3 {
  margin: 14px 0 8px;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.md-body ul, .md-body ol { margin: 8px 0 10px 22px; }
.md-body li { margin-bottom: 4px; }
.md-body pre {
  background: var(--bg-code);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 13px 15px;
  overflow-x: auto;
  margin: 10px 0;
}
.md-body code {
  font-family: "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  font-size: 13px;
}
.md-body :not(pre) > code {
  background: var(--bg-elevated);
  padding: 2px 6px;
  border-radius: 6px;
  color: var(--accent);
}
.md-body blockquote {
  border-left: 3px solid var(--accent);
  padding-left: 12px;
  color: var(--text-secondary);
  margin: 8px 0;
}
.md-body table {
  border-collapse: collapse;
  width: 100%;
  margin: 10px 0;
  font-size: 13.5px;
}
.md-body th, .md-body td {
  border: 1px solid var(--border-subtle);
  padding: 7px 10px;
  text-align: left;
}
.md-body th {
  background: var(--bg-elevated);
}

/* Empty Welcome State */
.empty-state {
  margin: auto;
  text-align: center;
  max-width: 520px;
  padding: 32px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.empty-hero-avatar {
  width: 64px;
  height: 64px;
  border-radius: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
}

.empty-state h2 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.empty-state p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.quick-prompts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-top: 6px;
}

.quick-chip {
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  font-size: 13px;
  color: var(--text-secondary);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: all 0.15s ease;
}

.quick-chip:hover {
  border-color: var(--accent);
  color: var(--text-primary);
  transform: translateY(-1px);
}

/* ==================== Apple Floating Composer ==================== */
.composer-wrap {
  padding: 10px 20px 18px;
  background: linear-gradient(180deg, transparent 0%, var(--bg-canvas) 35%);
}

.composer {
  max-width: 880px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-strong);
  border-radius: 22px;
  padding: 12px 14px;
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color 0.18s, box-shadow 0.18s, transform 0.15s;
}

.composer:focus-within,
.composer.drag-over {
  border-color: var(--accent);
  box-shadow: 0 10px 32px -4px rgba(198, 107, 78, 0.14), 0 0 0 3px var(--accent-soft);
}

.attachment-bar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}

.img-preview-item {
  position: relative;
  width: 60px;
  height: 60px;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-sm);
}

.img-preview-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-preview-item button,
.file-chip button {
  background: rgba(20, 18, 16, 0.72);
  color: #fff;
  border: none;
  border-radius: 50%;
  width: 18px;
  height: 18px;
  font-size: 11px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.img-preview-item button {
  position: absolute;
  top: 3px;
  right: 3px;
}

.file-chip {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: 11px;
  padding: 6px 10px;
  font-size: 12.5px;
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: var(--shadow-sm);
}

.file-chip-meta {
  font-size: 11px;
  color: var(--text-tertiary);
}

.composer textarea {
  width: 100%;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 14.5px;
  line-height: 1.55;
  resize: none;
  outline: none;
  max-height: 180px;
  min-height: 44px;
  font-family: inherit;
}

.composer-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.composer-left {
  display: flex;
  gap: 8px;
  align-items: center;
}

.composer-hint {
  font-size: 12px;
  color: var(--text-tertiary);
}

.composer-right {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  margin-left: auto;
}

/* ==================== Custom Apple Popover Model & Thinking Picker ==================== */
.model-picker-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
}

.model-trigger-btn {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 6px 11px;
  font-size: 12.5px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  box-shadow: var(--shadow-sm);
  transition: all 0.16s ease;
  user-select: none;
}

.model-trigger-btn:hover,
.model-picker-wrap.open .model-trigger-btn {
  background: var(--bg-card);
  border-color: var(--accent);
  box-shadow: 0 2px 10px rgba(198, 107, 78, 0.14);
}

.model-trigger-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
}

.model-trigger-name {
  font-weight: 600;
  max-width: 170px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.model-trigger-effort {
  font-size: 11px;
  font-weight: 600;
  padding: 1.5px 7px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  letter-spacing: 0.01em;
}

.model-trigger-chevron {
  color: var(--text-tertiary);
  transition: transform 0.2s cubic-bezier(0.22, 1, 0.36, 1);
  flex-shrink: 0;
}

.model-picker-wrap.open .model-trigger-chevron {
  transform: rotate(180deg);
  color: var(--accent);
}

/* Floating Popover Card above Composer */
.model-popover {
  position: absolute;
  bottom: calc(100% + 10px);
  right: 0;
  width: 390px;
  max-width: calc(100vw - 32px);
  background: var(--bg-card);
  backdrop-filter: blur(28px) saturate(190%);
  -webkit-backdrop-filter: blur(28px) saturate(190%);
  border: 1px solid var(--border-strong);
  border-radius: 18px;
  box-shadow: var(--shadow-lg);
  padding: 10px;
  z-index: 65;
  display: flex;
  flex-direction: column;
  gap: 8px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px) scale(0.97);
  transform-origin: bottom right;
  transition: opacity 0.18s ease, transform 0.2s cubic-bezier(0.22, 1, 0.36, 1), visibility 0.18s;
}

.model-picker-wrap.open .model-popover {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

.popover-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 2px 6px 4px;
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-subtle);
}

.popover-hint {
  font-size: 11px;
  font-weight: 400;
  color: var(--text-tertiary);
}

.popover-model-list {
  max-height: 250px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-right: 2px;
}

.popover-group-title {
  font-size: 10.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-tertiary);
  padding: 6px 8px 2px;
}

.popover-model-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 7px 9px;
  border-radius: 11px;
  cursor: pointer;
  transition: background 0.14s ease;
}

.popover-model-row:hover {
  background: var(--bg-hover);
}

.popover-model-row.active {
  background: var(--bg-active);
}

.popover-model-left {
  display: flex;
  align-items: center;
  gap: 7px;
  min-width: 0;
  flex: 1;
}

.popover-model-check {
  width: 14px;
  font-size: 12px;
  color: var(--accent);
  font-weight: 700;
  flex-shrink: 0;
  text-align: center;
}

.popover-model-title {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.popover-model-row.active .popover-model-title {
  font-weight: 600;
}

/* Right-side inline effort pills revealed on hover or active model row */
.row-effort-pills {
  display: flex;
  align-items: center;
  gap: 3px;
  opacity: 0;
  pointer-events: none;
  transform: translateX(4px);
  transition: opacity 0.14s ease, transform 0.14s ease;
  flex-shrink: 0;
}

.popover-model-row:hover .row-effort-pills,
.popover-model-row.active .row-effort-pills {
  opacity: 1;
  pointer-events: auto;
  transform: translateX(0);
}

.row-effort-pill {
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-size: 10.5px;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.12s ease;
}

.row-effort-pill:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

.row-effort-pill.selected {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* ChatGPT-style Unified Thinking Effort Slider Section */
.popover-slider-section {
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: 13px;
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.slider-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
}

.slider-title {
  font-weight: 600;
  color: var(--text-primary);
}

.slider-value-badge {
  font-size: 11px;
  font-weight: 700;
  padding: 1.5px 8px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
}

.effort-slider-wrap {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.effort-range-input {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 999px;
  background: var(--border-strong);
  outline: none;
  cursor: pointer;
  margin: 4px 0;
}

.effort-range-input::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2.5px solid #fff;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.22);
  cursor: grab;
  transition: transform 0.12s ease;
}

.effort-range-input::-webkit-slider-thumb:hover {
  transform: scale(1.12);
}

.effort-range-input::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2.5px solid #fff;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.22);
  cursor: grab;
}

.effort-ticks {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2px;
}

.effort-tick {
  font-size: 11px;
  font-weight: 500;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 2px 5px;
  border-radius: 6px;
  user-select: none;
  transition: all 0.12s ease;
}

.effort-tick:hover {
  color: var(--text-primary);
  background: var(--bg-hover);
}

.effort-tick.active {
  color: var(--accent);
  font-weight: 700;
  background: var(--accent-soft);
}

.send-btn {
  padding: 7px 15px;
  border-radius: 11px;
}

/* ==================== Modal ==================== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(25, 20, 15, 0.42);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 80;
  padding: 16px;
}

.modal-backdrop.open {
  display: flex;
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 22px;
  max-width: 440px;
  width: 100%;
  padding: 24px;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.modal h3 {
  font-size: 17px;
  font-weight: 600;
}

.form-label {
  font-size: 12.5px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: -8px;
}

@media (max-width: 860px) {
  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .menu-toggle {
    display: inline-flex;
  }
  .composer-hint {
    display: none;
  }
  .responses-grid.cols-2,
  .responses-grid.cols-3,
  .responses-grid.cols-4 {
    grid-template-columns: 1fr;
  }
}