/* ========== Design Tokens ========== */
:root {
  --bg-page: #f5f5f7;
  --bg-sidebar: #ffffff;
  --bg-bubble-user: #e8f0fe;
  --bg-bubble-ai: #ffffff;
  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #aeaeb2;
  --modal-sub: #4b4b55;
  --card-text: #1d1d1f;
  --input-border: #d4d4d8;
  --accent: #5e5ce6;
  --accent-hover: #4b49c9;
  --accent-soft: rgba(94, 92, 230, 0.08);
  --accent-glow: rgba(94, 92, 230, 0.15);
  --danger: #ff3b30;
  --success: #34c759;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 10px;
  --radius-full: 999px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.08);
  --transition: 0.15s ease;
  --border-color: #dcdcdf;
  --border-light: #eaeaed;
  --code-bg: #f8f8fa;
  --code-border: #dcdcdf;
  --input-bg: #ffffff;
  --sidebar-shadow: 2px 0 24px rgba(0,0,0,0.04);
  --overlay-bg: rgba(0,0,0,0.35);
  --conv-hover: #f8f8fa;
  --conv-active: var(--accent-soft);
  --bubble-shadow: 0 1px 4px rgba(0,0,0,0.04);
  --msg-gap: 12px;
  --scrollbar-color: #d1d1d6;
}
[data-theme="dark"] {
  --bg-page: #1c1c1e;
  --bg-sidebar: #2c2c2e;
  --bg-bubble-user: #3a3a3c;
  --bg-bubble-ai: #2c2c2e;
  --text-primary: #f5f5f7;
  --text-secondary: #98989d;
  --text-tertiary: #636366;
  --modal-sub: #cfcfd8;
  --card-text: #f5f5f7;
  --input-border: #48484a;
  --accent: #7d7aff;
  --accent-hover: #6b68f0;
  --accent-soft: rgba(125, 122, 255, 0.12);
  --accent-glow: rgba(125, 122, 255, 0.2);
  --danger: #ff453a;
  --success: #30d158;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.25);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.3);
  --border-color: #38383a;
  --border-light: #323234;
  --code-bg: #2c2c2e;
  --code-border: #38383a;
  --input-bg: #3a3a3c;
  --sidebar-shadow: 2px 0 24px rgba(0,0,0,0.2);
  --overlay-bg: rgba(0,0,0,0.6);
  --conv-hover: #3a3a3c;
  --conv-active: var(--accent-soft);
  --bubble-shadow: 0 1px 4px rgba(0,0,0,0.2);
  --scrollbar-color: #48484a;
}
* { margin:0; padding:0; box-sizing:border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: radial-gradient(1200px 800px at 80% -10%, rgba(94, 92, 230, 0.10), transparent 60%),
              radial-gradient(1000px 700px at 0% 110%, rgba(0, 190, 220, 0.07), transparent 60%),
              var(--bg-page);
  color: var(--text-primary);
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}
[data-theme="dark"] body {
  background: radial-gradient(1200px 800px at 80% -10%, rgba(125, 122, 255, 0.10), transparent 60%),
              radial-gradient(1000px 700px at 0% 110%, rgba(0, 180, 216, 0.08), transparent 60%),
              var(--bg-page);
}
.app-wrapper {
  display: flex;
  width: 100%;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

/* ========== Sidebar (drawer) ========== */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 280px;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 100;
  box-shadow: var(--sidebar-shadow);
}
.sidebar.open {
  transform: translateX(0);
}
.sidebar-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: var(--overlay-bg);
  z-index: 99;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}
.sidebar-overlay.active {
  opacity: 1;
  pointer-events: auto;
}
.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border-light);
}
.brand-text {
  font-weight: 600;
  font-size: 15px;
  letter-spacing: -0.2px;
  color: var(--text-primary);
}
.brand-icon {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
}
.sidebar-header {
  padding: 10px 12px;
}
.new-chat-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--input-bg);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
}
.new-chat-btn:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: 0 1px 4px var(--accent-glow);
}
.new-chat-btn:active {
  transform: scale(0.98);
}
.new-chat-btn span:first-child {
  font-size: 16px;
  color: var(--accent);
  font-weight: 600;
}
.conv-list {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 6px 8px;
  scroll-behavior: smooth;
  overscroll-behavior-y: contain;
}
.conv-list::-webkit-scrollbar { width: 4px; }
.conv-list::-webkit-scrollbar-thumb { background: var(--scrollbar-color); border-radius: var(--radius-full); }
.conv-item {
  padding: 10px 12px;
  margin-bottom: 2px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 10px;
  position: relative;
  font-size: 14px;
  color: var(--text-primary);
  min-height: 44px;
}
.conv-item:hover { background: var(--conv-hover); }
.conv-item.active { background: var(--conv-active); }
.conv-item .icon {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  flex-shrink: 0;
  transition: var(--transition);
}
.conv-item.active .icon {
  background: var(--accent);
  color: white;
}
.conv-item .title {
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
  line-height: 1.4;
  font-size: 13.5px;
}
.conv-item .conv-meta {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}
.conv-item .conv-time {
  font-size: 11px;
  color: var(--text-secondary);
  opacity: 0.5;
  user-select: none;
  flex-shrink: 0;
}
.conv-item .conv-more {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-sm);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: var(--transition);
  flex-shrink: 0;
  line-height: 1;
}
.conv-item:hover .conv-more { opacity: 0.4; }
.conv-item .conv-more:hover { opacity: 1; background: var(--conv-hover); }

/* ========== 多选删除 ========== */
.sidebar-header {
  display: flex;
  gap: 8px;
}
.multi-btn {
  flex-shrink: 0;
  padding: 0 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--input-bg);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
}
.multi-btn:hover { border-color: var(--accent); color: var(--accent); }
.multi-btn.active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}
.multi-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-bottom: 1px solid var(--border-color);
}
.multi-count {
  flex: 1;
  font-size: 12px;
  color: var(--text-secondary);
  white-space: nowrap;
}
.multi-del, .multi-cancel {
  flex-shrink: 0;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: var(--input-bg);
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-primary);
}
.multi-del { color: #e5484d; border-color: rgba(229, 72, 77, 0.45); }
.multi-del:hover { background: #e5484d; border-color: #e5484d; color: #fff; }
.multi-cancel:hover { border-color: var(--accent); color: var(--accent); }
.conv-check {
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--text-secondary);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 12px;
  line-height: 1;
  color: #fff;
  user-select: none;
  transition: var(--transition);
}
.conv-item.selected { background: var(--accent-soft); }
.conv-item.selected .conv-check {
  background: var(--accent);
  border-color: var(--accent);
}

/* ========== Conv Dropdown ========== */
.conv-dropdown {
  position: fixed;
  z-index: 300;
  min-width: 130px;
  background: var(--bg-sidebar);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: 4px;
  opacity: 0;
  pointer-events: none;
  transform: scale(0.95);
  transition: opacity 0.12s ease, transform 0.12s ease;
}
.conv-dropdown.active {
  opacity: 1;
  pointer-events: auto;
  transform: scale(1);
}
.conv-dropdown .dd-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  font-size: 13px;
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.1s ease;
  user-select: none;
  white-space: nowrap;
}
.conv-dropdown .dd-item svg { flex-shrink: 0; }
.conv-dropdown .dd-item:hover { background: var(--conv-hover); }
.conv-dropdown .dd-item.danger { color: var(--danger); }
.conv-dropdown .dd-item.danger:hover { background: rgba(255,59,48,0.08); }

/* ========== Main ========== */
.main-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  background: var(--bg-page);
}
.chat { display: flex; flex-direction: column; flex: 1; min-height: 0; }

/* ========== Top Bar ========== */
.chat-topbar {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--bg-page);
  border-bottom: 1px solid var(--border-light);
  min-height: 48px;
}
#showSidebarBtn {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
}
#themeToggle {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
}
.topbar-btn {
  width: 32px; height: 32px;
  border-radius: var(--radius-sm);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  flex-shrink: 0;
}
.topbar-btn:hover { color: var(--text-primary); background: var(--conv-hover); }
.persona-select {
  height: 30px;
  max-width: 180px;
  padding: 0 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--card-text);
  font-size: 13px;
  outline: none;
  cursor: pointer;
  flex-shrink: 0;
}
.persona-select:focus { border-color: var(--accent); }
.persona-select.disabled {
  opacity: 0.55;
  cursor: not-allowed;
  pointer-events: none;
}
#themeToggle { display: inline-flex; align-items: center; justify-content: center; }
#themeToggle .icon-sun { display: none; }
#themeToggle svg { display: inline; }
[data-theme="dark"] #themeToggle .icon-sun { display: inline; }
[data-theme="dark"] #themeToggle .icon-moon { display: none; }
.logout-link {
  font-size: 13px;
  color: var(--text-secondary);
  cursor: pointer;
  background: none;
  border: none;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.logout-link:hover { color: var(--danger); background: rgba(255,59,48,0.08); }

/* ========== Messages ========== */
.messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px 20px 0;
  display: flex;
  flex-direction: column;
  gap: var(--msg-gap);
  max-width: 760px;
  width: 100%;
  margin: 0 auto;
  position: relative;
}
.messages::-webkit-scrollbar { width: 4px; }
.messages::-webkit-scrollbar-thumb { background: var(--scrollbar-color); border-radius: var(--radius-full); }

.msg {
  position: relative;
  display: flex;
  flex-direction: row;
  align-items: flex-start;
  gap: 8px;
  max-width: 88%;
  animation: msgFadeIn 0.25s ease;
}
@keyframes msgFadeIn { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
.msg.user { align-self: flex-end; flex-direction: row-reverse; }
.msg.assistant { align-self: flex-start; max-width: 96%; }
.msg-body { display: flex; flex-direction: column; min-width: 0; max-width: 100%; }
.msg.user .msg-body { align-items: flex-end; }
.msg.assistant .msg-body { align-items: flex-start; }
.msg-name {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 4px;
  user-select: none;
  line-height: 1.3;
}
.msg-avatar {
  flex: 0 0 auto;
  width: 30px;
  height: 30px;
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: var(--bubble-shadow);
}
.avatar-user { background: linear-gradient(135deg, #5e5ce6, #8b5cf6); }
.avatar-ai { background: linear-gradient(135deg, #5e5ce6, #06b6d4); }
.msg-bubble {
  padding: 2px 4px;
  font-size: 14px;
  line-height: 1.6;
  word-break: break-word;
  overflow-wrap: break-word;
  max-width: 100%;
}
.msg.user .msg-bubble {
  background: var(--bg-bubble-user);
  color: var(--text-primary);
  border-radius: var(--radius-xl) var(--radius-xl) 6px var(--radius-xl);
  padding: 12px 16px;
}
.msg.assistant .msg-bubble {
  background: transparent;
  color: var(--text-primary);
  border-radius: 0;
  padding-top: 4px;
}
.empty-hint {
  color: var(--text-secondary);
  font-style: italic;
  font-size: 13px;
}
.reasoning-box {
  margin-bottom: 8px;
  background: var(--code-bg);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  font-size: 14px;
  color: var(--text-secondary);
  cursor: pointer;
}
.reasoning-box.forced-visible { min-height: 36px; overflow: visible; }
.reasoning-box summary { font-weight: 500; color: var(--accent); margin-bottom: 4px; }
.reasoning-box[open] summary { margin-bottom: 6px; }
.reasoning-text { font-size: 13px; line-height: 1.6; white-space: pre-wrap; }

/* ========== Code Blocks ========== */
.code-block-wrapper {
  position: relative;
  margin: 10px 0;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.code-toolbar {
  position: absolute;
  top: 6px;
  right: 6px;
  display: flex;
  gap: 4px;
  z-index: 10;
  opacity: 0;
  transition: opacity 0.2s ease;
}
.code-block-wrapper:hover .code-toolbar { opacity: 1; }
.code-toolbar-btn {
  padding: 4px 10px;
  border: none;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-sm);
  font-size: 11px;
  cursor: pointer;
  color: var(--text-secondary);
  line-height: 1.4;
  white-space: nowrap;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  transition: var(--transition);
}
.code-toolbar-btn:hover {
  background: #fff;
  color: var(--text-primary);
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}
[data-theme="dark"] .code-toolbar-btn { background: rgba(44,44,46,0.9); }
[data-theme="dark"] .code-toolbar-btn:hover { background: rgba(58,58,60,0.95); }
.code-block-wrapper > pre {
  margin: 0;
  padding: 12px;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
  background: transparent;
  border-radius: 0;
}
.code-block-wrapper > pre > code {
  background: none;
  padding: 0;
  font-size: 0.9em;
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
}
.msg-bubble > pre {
  background: var(--code-bg);
  border-radius: var(--radius-sm);
  padding: 12px;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
  margin: 8px 0;
  font-size: 0.9em;
}
.msg-bubble > pre > code {
  background: none;
  padding: 0;
  font-size: inherit;
}

/* ========== Input Area ========== */
.input-section {
  padding: 8px 20px 14px;
  max-width: 820px;
  width: 100%;
  margin: 0 auto;
  position: relative;
}
.toolbar-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
  padding: 0 4px;
}
.tool-toggle {
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: var(--conv-hover);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
  user-select: none;
  border: none;
}
.tool-toggle:hover { background: var(--border-color); }
.tool-toggle input {
  margin: 0;
  accent-color: var(--accent);
  width: 13px;
  height: 13px;
}
.tool-toggle.active { background: var(--accent-soft); color: var(--accent); }
.tool-spacer { flex: 1; }

.input-wrapper {
  display: flex;
  align-items: flex-end;
  background: var(--input-bg);
  border-radius: var(--radius-lg);
  padding: 4px 4px 4px 14px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.input-wrapper:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.input-wrapper textarea {
  flex: 1;
  border: none;
  padding: 8px 0;
  font-size: 14px;
  outline: none;
  background: transparent;
  color: var(--text-primary);
  resize: none;
  overflow-y: auto;
  max-height: 180px;
  min-height: 22px;
  line-height: 1.5;
  font-family: inherit;
}
.input-wrapper textarea::placeholder { color: var(--text-tertiary); }
.input-wrapper textarea::-webkit-scrollbar { width: 4px; }
.input-wrapper textarea::-webkit-scrollbar-thumb { background: var(--scrollbar-color); border-radius: var(--radius-full); }
/* ========== AI Selector ========== */
.ai-selector-group {
  display: flex;
  align-items: center;
}
.ai-selector {
  appearance: auto;
  background: var(--conv-hover);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  outline: none;
  max-width: 160px;
  transition: var(--transition);
}
.ai-selector:hover { border-color: var(--accent); }
.ai-selector:focus { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-glow); }


.send-btn {
  width: 34px; height: 34px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: white;
  border: none;
  cursor: pointer;
  font-size: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  flex-shrink: 0;
}
.send-btn:hover { background: var(--accent-hover); transform: scale(1.05); }
.send-btn:active { transform: scale(0.95); }
.send-btn:disabled { opacity: 0.4; cursor: default; transform: none; }
.stop-btn { background: var(--danger); }
.stop-btn:hover { background: #d62d20; }
.hidden { display: none !important; }

/* ========== Welcome Screen ========== */
.welcome-screen {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 32px 24px;
  gap: 8px;
  animation: msgFadeIn 0.5s ease;
  position: relative;
}
.welcome-screen > .welcome-icon,
.welcome-screen > .welcome-title,
.welcome-screen > .welcome-sub,
.welcome-screen > .welcome-hints {
  position: relative;
  z-index: 1;
}
.welcome-icon {
  width: 66px; height: 66px;
  border-radius: 20px;
  background: linear-gradient(135deg, #5e5ce6, #06b6d4);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  margin-bottom: 8px;
  box-shadow: 0 10px 28px var(--accent-glow), 0 2px 10px rgba(94,92,230,0.28);
  animation: welcomeFloat 4.5s ease-in-out infinite;
}
@keyframes welcomeFloat { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-6px); } }
.welcome-title {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.3px;
  background: linear-gradient(90deg, #5e5ce6, #0ea5e9);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.welcome-sub {
  font-size: 14px;
  color: var(--text-secondary);
  max-width: 300px;
  line-height: 1.5;
}
.welcome-hints {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-top: 20px;
  width: 100%;
  max-width: 520px;
}
.welcome-hint-item {
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--input-bg);
  border: 1px solid var(--border-color);
  font-size: 13px;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
  box-shadow: var(--shadow-sm);
}
.welcome-hint-item:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
  box-shadow: var(--bubble-shadow);
}

/* ========== Scroll Bottom ========== */
.scroll-bottom-btn {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--input-bg);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 15px;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 5;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}
.scroll-bottom-btn.visible { opacity: 1; pointer-events: auto; }
.scroll-bottom-btn:hover { background: var(--conv-hover); transform: translateX(-50%) translateY(-2px); }

/* ========== Misc Message Styles ========== */
.msg-time {
  font-size: 11px;
  color: var(--text-tertiary);
  margin-top: 4px;
  user-select: none;
}
.msg.user .msg-time { text-align: right; }
.msg.grouped { margin-top: -10px; }
.msg.grouped .msg-time, .msg.grouped .reasoning-box { display: none; }
.msg.user.grouped .msg-bubble { border-radius: var(--radius-xl) var(--radius-sm) 6px var(--radius-xl); }
.msg.assistant.grouped .msg-bubble { border-radius: var(--radius-sm) var(--radius-xl) var(--radius-xl) 6px; }
.msg-actions {
  display: flex;
  gap: 4px;
  opacity: 0;
  transition: opacity 0.15s;
  margin-top: 2px;
}
.msg:hover .msg-actions { opacity: 1; }
.msg-actions button {
  background: none;
  border: none;
  font-size: 12px;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.msg-actions button:hover { background: var(--conv-hover); color: var(--text-primary); }
.msg-actions button.solid {
  background: var(--accent);
  color: #fff;
  padding: 4px 14px;
  font-weight: 500;
}
.msg-actions button.solid:hover { background: var(--accent); color: #fff; }

/* ========== Edit Box ========== */
.edit-box {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
  max-width: 560px;
}
.edit-textarea {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  border: 1px solid var(--accent);
  background: var(--input-bg);
  color: var(--card-text);
  font-size: 14px;
  font-family: inherit;
  line-height: 1.6;
  resize: vertical;
  outline: none;
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.edit-actions {
  display: flex;
  justify-content: flex-end;
  gap: 6px;
}
.edit-actions .msg-action-btn {
  padding: 5px 14px;
  font-size: 12px;
  font-weight: 500;
  border-radius: var(--radius-sm);
}

/* ========== Streaming Pulse ========== */
@keyframes pulse-dot { 0%,80%,100% { transform:scale(0.6); opacity:0.4; } 40% { transform:scale(1); opacity:1; } }
.streaming-dots {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  margin-left: 2px;
}
.streaming-dots span {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse-dot 1.4s ease-in-out infinite;
}
.streaming-dots span:nth-child(2) { animation-delay:0.2s; }
.streaming-dots span:nth-child(3) { animation-delay:0.4s; }

/* ========== Toast ========== */
.toast-container {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1200;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  pointer-events: none;
}
.toast {
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-size: 14px;
  background: #1d1d1f;
  color: #fff;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.25s ease, toastOut 0.25s ease 2.5s forwards;
  pointer-events: auto;
  max-width: 360px;
  text-align: center;
}
[data-theme="dark"] .toast { background: #f5f5f7; color: #1d1d1f; }
.toast.error { background: var(--danger); color: #fff; }
.toast.success { background: var(--success); color: #fff; }
@keyframes toastIn { from { opacity:0; transform:translateY(12px); } to { opacity:1; transform:translateY(0); } }
@keyframes toastOut { from { opacity:1; } to { opacity:0; } }

/* ========== Settings Modal ========== */
.modal-overlay {
  position: fixed;
  inset: 0;
  /* 纯色深遮罩：避免 backdrop-filter 全屏实时模糊导致的卡顿，0.72 暗度已足以遮挡背景 */
  background: rgba(8, 8, 12, 0.72);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}
body.modal-open { overflow: hidden; }
.modal {
  background: var(--bg-sidebar);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 18px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.28);
  width: 100%;
  max-width: 420px;
  max-height: 90vh;
  overflow-y: auto;
  padding: 22px;
  box-sizing: border-box;
}
.modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 14px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border-light);
}
.modal-heading { min-width: 0; }
.modal-title {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.2px;
  color: var(--text-primary);
}
.modal-title::before {
  content: '';
  flex-shrink: 0;
  width: 4px;
  height: 20px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--accent), var(--accent-hover));
}
.modal-sub {
  margin-top: 7px;
  margin-left: 13px;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--modal-sub);
}
.modal-sub strong { color: var(--accent); font-weight: 700; }
.modal-close {
  flex-shrink: 0;
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 16px;
  cursor: pointer;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s ease, color 0.15s ease;
}
.modal-close:hover { background: var(--conv-hover); color: var(--text-primary); }
.settings-group { margin-bottom: 14px; }
.modal-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}
.modal-input-wrap { position: relative; }
.modal-input-wrap .modal-input { padding-right: 42px; }
.modal-eye {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  border: none;
  background: none;
  cursor: pointer;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: background 0.15s ease, color 0.15s ease;
}
.modal-eye:hover { background: var(--conv-hover); color: var(--text-primary); }
.modal-eye svg { width: 18px; height: 18px; display: block; }
.modal-input {
  width: 100%;
  padding: 11px 12px;
  border: 1.5px solid var(--input-border);
  border-radius: 10px;
  font-size: 14px;
  background: var(--input-bg);
  color: var(--text-primary);
  outline: none;
  box-sizing: border-box;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.modal-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(79, 110, 247, 0.14); }
.modal-select {
  appearance: auto;
  cursor: pointer;
  height: 44px;
}
.modal-fetch { width: 100%; }
.modal-verify {
  margin-top: 10px;
  margin-bottom: 2px;
  padding: 9px 12px;
  border-radius: 10px;
  font-size: 13px;
  line-height: 1.5;
  box-sizing: border-box;
}
.modal-verify.ok { background: rgba(34, 160, 98, 0.1); color: var(--success); }
.modal-verify.err { background: rgba(217, 48, 37, 0.08); color: var(--danger); }
.modal-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 18px;
}
.modal-hint { font-size: 12px; color: var(--text-secondary); }
.modal-footer-actions { display: flex; gap: 10px; margin-left: auto; }
.modal-btn {
  padding: 9px 16px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: filter 0.15s ease, background 0.15s ease;
}
.modal-btn:disabled { opacity: 0.55; cursor: not-allowed; }
.modal-btn.primary { background: var(--accent); color: #fff; }
.modal-btn.primary:hover:not(:disabled) { filter: brightness(1.08); }
.modal-btn.danger {
  background: transparent;
  color: var(--danger);
  border: 1px solid var(--danger);
}
.modal-btn.danger:hover { background: rgba(217, 48, 37, 0.08); }
/* 弹窗打开动画 */
.modal-overlay { animation: overlayIn 0.18s ease-out; }
.modal-overlay .modal { animation: modalIn 0.22s cubic-bezier(0.16, 1, 0.3, 1); }
@keyframes overlayIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes modalIn { from { opacity: 0; transform: scale(0.94) translateY(10px); } to { opacity: 1; transform: scale(1) translateY(0); } }

/* ========== Code Lang Tag ========== */
.code-lang-tag {
  position: absolute;
  top: 6px;
  left: 10px;
  font-size: 11px;
  color: var(--text-tertiary);
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  text-transform: lowercase;
  user-select: none;
}

/* ========== Skeleton ========== */
@keyframes skeletonPulse { 0%,100% { opacity:0.4; } 50% { opacity:0.8; } }
.skeleton-container {
  display:flex; flex-direction:column; gap:18px; padding:20px 20px 0; max-width:820px; width:100%; margin:0 auto;
}
.skeleton-item { display:flex; flex-direction:column; max-width:75%; }
.skeleton-item.right { align-self:flex-end; }
.skeleton-item.left { align-self:flex-start; }
.skeleton-bubble { padding:20px 24px; border-radius:var(--radius-xl); background:var(--bg-bubble-ai); box-shadow:var(--bubble-shadow); }
.skeleton-item.right .skeleton-bubble { background:var(--bg-bubble-user); }
.skeleton-item.left .skeleton-bubble { background:transparent; box-shadow:none; padding:4px 4px 0; }
.skeleton-line { height:12px; border-radius:6px; background:var(--border-color); animation:skeletonPulse 1.5s ease-in-out infinite; margin-bottom:8px; }
.skeleton-line:last-child { margin-bottom:0; }
.skeleton-line.w60 { width:60%; }
.skeleton-line.w80 { width:80%; }
.skeleton-line.w40 { width:40%; }

/* ========== Msg Retry ========== */
.msg-retry-btn {
  display:inline-flex; align-items:center; gap:4px; margin-top:8px; padding:5px 14px;
  font-size:12px; font-weight:500; color:var(--danger);
  background:transparent; border:1px solid rgba(255,59,48,0.25); border-radius:var(--radius-sm);
  cursor:pointer; transition:var(--transition);
}
.msg-retry-btn:hover { background:rgba(255,59,48,0.08); border-color:var(--danger); }


/* ========== Chat title in topbar ========== */
.chat-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 200px;
}

/* 自定义 AI 徽章：配置了用户自己的 API Key 时显示 */
.custom-ai-badge {
  flex-shrink: 0;
  font-size: 11px;
  font-weight: 600;
  line-height: 1;
  padding: 3px 7px;
  border-radius: 999px;
  color: #fff;
  background: linear-gradient(135deg, #4f7cff, #7c5cff);
  white-space: nowrap;
  cursor: default;
}

@media (max-width: 768px) {
  .custom-ai-badge { font-size: 10px; padding: 2px 6px; }
}

@media (max-width: 768px) {
  .chat-title { max-width: 150px; }
  .chat-topbar { padding: 6px 10px; min-height: 44px; gap: 4px; }
  #showSidebarBtn { left: 8px; }
  #themeToggle { right: 8px; }
  .persona-select { max-width: 100px; height: 28px; padding: 0 6px; font-size: 12px; }
  .topbar-btn { width: 30px; height: 30px; font-size: 15px; }
  .logout-link { padding: 4px 8px; font-size: 12px; }
  .messages { padding: 4px 6px 0; max-width: 100%; }
  .msg { max-width: 94%; }
  .msg-bubble { padding: 10px 12px; font-size: 14px; }
  .msg-time { font-size: 10px; margin-top: 2px; }
  .input-section { padding: 4px 8px 6px; }
  .toolbar-row { margin-bottom: 4px; padding: 0; gap: 4px; flex-wrap: nowrap; overflow-x: auto; }
  .tool-toggle { padding: 6px 10px; font-size: 12px; white-space: nowrap; flex-shrink: 0; }
  .ai-selector { font-size: 12px; padding: 3px 8px; max-width: 140px; }
  .input-wrapper { padding: 2px 2px 2px 10px; border-radius: var(--radius-lg); }
  .input-wrapper textarea { font-size: 14px; padding: 8px 0; max-height: 100px; min-height: 22px; }
  .send-btn { width: 32px; height: 32px; font-size: 14px; border-radius: var(--radius-md); }
  .stop-btn { width: 32px; height: 32px; font-size: 14px; border-radius: var(--radius-md); }
  .code-toolbar { top: 4px; right: 4px; }
  .code-toolbar-btn { padding: 2px 6px; font-size: 10px; }
  .sidebar .brand { padding: 14px 16px; }
  .sidebar-header { padding: 10px 12px; }
  .conv-item { padding: 10px 12px; min-height: 44px; font-size: 14px; }
  .welcome-icon { width: 56px; height: 56px; font-size: 24px; border-radius: 16px; }
  .welcome-title { font-size: 20px; }
  .welcome-sub { font-size: 14px; }
  .welcome-hints { margin-top: 14px; gap: 8px; }
  .welcome-hint-item { padding: 10px 12px; font-size: 12px; }
  #scrollBottomBtn { bottom: 12px; }
}

.hljs { display:block; overflow-x:auto; padding:0; background:none; color:#24292e; }
.hljs-comment,.hljs-quote { color:#6a737d; font-style:italic; }
.hljs-keyword,.hljs-selector-tag,.hljs-subst { color:#d73a49; font-weight:600; }
.hljs-number,.hljs-literal,.hljs-variable,.hljs-template-variable,.hljs-tag .hljs-attr { color:#005cc5; }
.hljs-string,.hljs-doctag { color:#032f62; }
.hljs-title,.hljs-section,.hljs-selector-id { color:#6f42c1; }
.hljs-type,.hljs-class .hljs-title { color:#6f42c1; }
.hljs-tag,.hljs-name,.hljs-attribute { color:#22863a; }
.hljs-regexp,.hljs-link { color:#032f62; }
.hljs-symbol,.hljs-bullet { color:#e36209; }
.hljs-built_in,.hljs-builtin-name { color:#005cc5; }
.hljs-meta { color:#6a737d; }
.hljs-deletion { background:#ffeef0; }
.hljs-addition { background:#f0fff4; }
.hljs-emphasis { font-style:italic; }
.hljs-strong { font-weight:600; }

[data-theme="dark"] .hljs { color:#c9d1d9; }
[data-theme="dark"] .hljs-comment,.hljs-quote { color:#8b949e; }
[data-theme="dark"] .hljs-keyword,.hljs-selector-tag,.hljs-subst { color:#ff7b72; }
[data-theme="dark"] .hljs-number,.hljs-literal,.hljs-variable,.hljs-template-variable,.hljs-tag .hljs-attr { color:#79c0ff; }
[data-theme="dark"] .hljs-string,.hljs-doctag { color:#a5d6ff; }
[data-theme="dark"] .hljs-title,.hljs-section,.hljs-selector-id { color:#d2a8ff; }
[data-theme="dark"] .hljs-type,.hljs-class .hljs-title { color:#d2a8ff; }
[data-theme="dark"] .hljs-tag,.hljs-name,.hljs-attribute { color:#7ee787; }
[data-theme="dark"] .hljs-regexp,.hljs-link { color:#a5d6ff; }
[data-theme="dark"] .hljs-symbol,.hljs-bullet { color:#ffa657; }
[data-theme="dark"] .hljs-built_in,.hljs-builtin-name { color:#79c0ff; }
[data-theme="dark"] .hljs-meta { color:#8b949e; }
[data-theme="dark"] .hljs-deletion { background:rgba(248,81,73,0.15); }
[data-theme="dark"] .hljs-addition { background:rgba(63,185,80,0.15); }