/* ================== 设计令牌 ================== */
:root {
  --font-base: 18px;
  --font-sans: "Inter", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  /* 深色主题（默认） */
  --bg: #070a17;
  --bg-soft: #0d132a;
  --bg-elev: #151c3d;
  --panel: #10172e;
  --border: #212a54;
  --border-soft: #1a234a;
  --text: #eef0fa;
  --text-muted: #8d95b8;
  --primary: #6366f1;
  --primary-hover: #7c7ff3;
  --primary-soft: rgba(99, 102, 241, 0.14);
  --accent: #22d3ee;
  --accent-soft: rgba(34, 211, 238, 0.14);
  --danger: #f87171;
  --success: #4ade80;

  --radius: 16px;
  --radius-lg: 22px;
  --radius-sm: 10px;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 20px 60px rgba(5, 10, 30, 0.55);
  --glow-primary: 0 0 0 3px rgba(99, 102, 241, 0.22);

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
}

[data-theme="light"] {
  --bg: #f4f6fb;
  --bg-soft: #ffffff;
  --bg-elev: #f0f2f9;
  --panel: #ffffff;
  --border: #e4e7f1;
  --border-soft: #eff1f7;
  --text: #111733;
  --text-muted: #5b6478;
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-soft: rgba(79, 70, 229, 0.1);
  --accent: #0891b2;
  --accent-soft: rgba(8, 145, 178, 0.1);
  --shadow-sm: 0 2px 6px rgba(20, 30, 60, 0.05);
  --shadow: 0 8px 24px rgba(20, 30, 60, 0.08);
  --shadow-lg: 0 20px 50px rgba(20, 30, 60, 0.12);
  --glow-primary: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0; height: 100%;
  background: var(--bg);
  color: var(--text);
  font-size: var(--font-base);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

button { font-family: inherit; font-size: inherit; cursor: pointer; }
textarea, input, select { font-family: inherit; font-size: inherit; color: inherit; }

/* 全局动画定义 */
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.45; transform: scale(0.75); }
}
@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.92); }
  to   { opacity: 1; transform: scale(1); }
}
@keyframes modalIn {
  from { opacity: 0; transform: translateY(20px) scale(0.96); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}
@keyframes orbRotate { to { transform: rotate(360deg); } }
@keyframes orbFloat {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
@keyframes typingDot {
  0%, 60%, 100% { opacity: 0.25; transform: translateY(0); }
  30% { opacity: 1; transform: translateY(-3px); }
}
@keyframes caretBlink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}
@keyframes glowPulse {
  0%, 100% { box-shadow: 0 0 0 0 var(--primary-soft); }
  50%      { box-shadow: 0 0 0 6px transparent; }
}

/* 偏好：用户减少动效 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ================== 应用布局 ================== */
#app {
  position: relative;
  display: flex;
  height: 100vh;
  overflow: hidden;
  isolation: isolate;
}

/* 背景环境光晕（装饰） */
#app::before, #app::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
}
#app::before {
  background:
    radial-gradient(60% 40% at 8% 0%, rgba(99, 102, 241, 0.18), transparent 60%),
    radial-gradient(50% 40% at 92% 100%, rgba(34, 211, 238, 0.12), transparent 60%);
  opacity: 1;
}
[data-theme="light"] #app::before {
  background:
    radial-gradient(60% 40% at 8% 0%, rgba(79, 70, 229, 0.06), transparent 60%),
    radial-gradient(50% 40% at 92% 100%, rgba(8, 145, 178, 0.05), transparent 60%);
}

/* ================== 侧边栏 ================== */
.sidebar {
  width: 300px;
  flex-shrink: 0;
  background: color-mix(in srgb, var(--bg-soft) 92%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  transition: margin-left 0.3s var(--ease-out);
}
.sidebar.collapsed { margin-left: -300px; }

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 18px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-name {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
  background: linear-gradient(135deg, var(--text) 0%, color-mix(in srgb, var(--primary) 60%, var(--text)) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.new-chat-btn {
  margin: 6px 14px 14px;
  padding: 13px 14px;
  background: linear-gradient(135deg, var(--primary), color-mix(in srgb, var(--primary) 70%, var(--accent)));
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center; gap: 10px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.01em;
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.32);
  transition: transform 0.18s var(--ease-out), box-shadow 0.18s var(--ease-out), filter 0.18s var(--ease-out);
}
.new-chat-btn:hover { transform: translateY(-1px); filter: brightness(1.05); box-shadow: 0 10px 24px rgba(99, 102, 241, 0.42); }
.new-chat-btn:active { transform: translateY(0) scale(0.98); }
.new-chat-btn svg { transition: transform 0.3s var(--ease-out); }
.new-chat-btn:hover svg { transform: rotate(90deg); }

.session-list {
  flex: 1;
  overflow-y: auto;
  padding: 4px 10px 10px;
}

.session-item {
  position: relative;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 12px 11px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--text);
  transition: background 0.18s var(--ease-out), transform 0.18s var(--ease-out);
  margin-bottom: 3px;
  animation: fadeSlideUp 0.3s var(--ease-out) both;
}
.session-item::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 50%;
  width: 3px;
  height: 0;
  background: linear-gradient(180deg, var(--primary), var(--accent));
  border-radius: 3px;
  transform: translateY(-50%);
  transition: height 0.25s var(--ease-out);
}
.session-item:hover { background: var(--bg-elev); }
.session-item.active { background: var(--primary-soft); }
.session-item.active::before { height: 60%; }
.session-item .session-name {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-size: 15px;
}
.session-item .session-actions {
  display: flex;
  gap: 2px;
  opacity: 0;
  transform: translateX(4px);
  transition: opacity 0.18s var(--ease-out), transform 0.18s var(--ease-out);
}
.session-item:hover .session-actions,
.session-item.active .session-actions { opacity: 1; transform: translateX(0); }
.session-item button.icon-btn {
  padding: 4px;
  color: var(--text-muted);
}
.session-item button.icon-btn:hover { color: var(--text); }

.sidebar-footer {
  display: flex;
  gap: 6px;
  padding: 10px 14px 14px;
  border-top: 1px solid var(--border-soft);
}
.footer-btn {
  flex: 1;
  padding: 10px 8px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 14px;
  display: flex; align-items: center; justify-content: center; gap: 6px;
  transition: background 0.15s var(--ease-out), border-color 0.15s var(--ease-out), color 0.15s var(--ease-out);
}
.footer-btn:hover { background: var(--bg-elev); border-color: var(--primary); color: var(--primary); }

.expand-sidebar-btn {
  position: fixed;
  left: 12px;
  top: 14px;
  z-index: 10;
  width: 40px; height: 40px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-sm);
  animation: fadeIn 0.25s var(--ease-out);
  transition: background 0.15s var(--ease-out), transform 0.15s var(--ease-out);
}
.expand-sidebar-btn:hover { background: var(--bg-elev); transform: translateX(2px); }

/* ================== 主聊天区 ================== */
.chat-main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  background: transparent;
}

.chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  border-bottom: 1px solid var(--border-soft);
  background: color-mix(in srgb, var(--bg-soft) 75%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  gap: 16px;
  position: sticky;
  top: 0;
  z-index: 5;
}
.header-left { display: flex; align-items: center; gap: 12px; min-width: 0; }
.session-title {
  margin: 0;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.header-right { display: flex; align-items: center; gap: 12px; }

.model-select-wrap {
  display: flex; align-items: center; gap: 10px;
  background: var(--bg-elev);
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  transition: border-color 0.15s var(--ease-out), background 0.15s var(--ease-out);
}
.model-select-wrap:hover { border-color: var(--primary); }
.model-label { font-size: 13px; color: var(--text-muted); letter-spacing: 0.05em; text-transform: uppercase; }
.model-select {
  background: transparent;
  border: none;
  outline: none;
  color: var(--text);
  font-size: 15px;
  font-weight: 500;
  max-width: 280px;
  cursor: pointer;
}

/* ================== 欢迎 ================== */
.welcome {
  flex: 1;
  display: flex; align-items: center; justify-content: center;
  padding: 32px;
  overflow-y: auto;
  animation: fadeIn 0.4s var(--ease-out);
}
.welcome[hidden] { display: none !important; }
.welcome-inner { max-width: 820px; width: 100%; text-align: center; }

/* 动画 Orb（品牌图形） */
.welcome-orb {
  position: relative;
  width: 120px;
  height: 120px;
  margin: 0 auto 28px;
  animation: orbFloat 5s ease-in-out infinite;
}
.welcome-orb .orb-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: conic-gradient(from 0deg,
    var(--primary) 0%,
    var(--accent) 25%,
    var(--primary) 50%,
    var(--accent) 75%,
    var(--primary) 100%);
  filter: blur(2px);
  animation: orbRotate 8s linear infinite;
  mask: radial-gradient(circle, transparent 50%, #000 52%, #000 100%);
  -webkit-mask: radial-gradient(circle, transparent 50%, #000 52%, #000 100%);
}
.welcome-orb::after {
  content: "";
  position: absolute;
  inset: -20px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--primary-soft), transparent 60%);
  filter: blur(16px);
  z-index: -1;
}
.welcome-orb .orb-core {
  position: absolute;
  inset: 14px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex; align-items: center; justify-content: center;
  box-shadow: inset 0 -8px 20px rgba(0,0,0,0.2), 0 8px 24px rgba(99,102,241,0.35);
}
.welcome h2 {
  font-size: 34px;
  margin: 0 0 12px;
  font-weight: 700;
  letter-spacing: -0.02em;
  animation: fadeSlideUp 0.5s var(--ease-out) 0.1s both;
}
.brand-gradient {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.welcome p {
  font-size: 17px;
  color: var(--text-muted);
  margin: 0 0 40px;
  animation: fadeSlideUp 0.5s var(--ease-out) 0.2s both;
}
.welcome-tips {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
}
.tip-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  background: color-mix(in srgb, var(--bg-soft) 80%, transparent);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 15px;
  text-align: left;
  color: var(--text);
  transition: transform 0.2s var(--ease-out), border-color 0.2s var(--ease-out), box-shadow 0.2s var(--ease-out), background 0.2s var(--ease-out);
  animation: fadeSlideUp 0.5s var(--ease-out) calc(0.3s + var(--i, 0) * 0.08s) both;
}
.tip-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
  box-shadow: 0 12px 28px rgba(99, 102, 241, 0.18);
  background: var(--bg-soft);
}
.tip-card:active { transform: translateY(-1px) scale(0.99); }
.tip-icon {
  width: 40px; height: 40px;
  flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  border-radius: 10px;
  background: var(--primary-soft);
  color: var(--primary);
  transition: background 0.2s var(--ease-out), color 0.2s var(--ease-out);
}
.tip-card:hover .tip-icon { background: var(--primary); color: #fff; }
.tip-text { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.tip-title { font-size: 15px; font-weight: 600; }
.tip-sub { font-size: 13px; color: var(--text-muted); }

/* ================== 消息区 ================== */
.messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px 0 40px;
  scroll-behavior: smooth;
}
.message-wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 4px 28px;
  animation: fadeSlideUp 0.35s var(--ease-out);
}
.message {
  display: flex;
  gap: 14px;
  padding: 18px 0;
  align-items: flex-start;
}
.message .avatar {
  width: 36px; height: 36px; flex-shrink: 0;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  font-size: 14px;
  color: #fff;
  box-shadow: var(--shadow-sm);
  position: relative;
}
.message.user .avatar {
  background: linear-gradient(135deg, #3b4e7a, #4b5d8f);
}
.message.assistant .avatar {
  background: linear-gradient(135deg, var(--primary), var(--accent));
}
.message.assistant .avatar::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 10px;
  background: linear-gradient(135deg, rgba(255,255,255,0.3), transparent 55%);
}
.message .bubble {
  flex: 1;
  min-width: 0;
  font-size: var(--font-base);
  line-height: 1.75;
}
.message .role-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 6px;
  letter-spacing: 0.02em;
}
.message .content { word-wrap: break-word; overflow-wrap: anywhere; }

/* 流式中的闪烁光标（只在正文末尾出现） */
.message.assistant.streaming .content > .text-content:last-child::after {
  content: "";
  display: inline-block;
  width: 2px;
  height: 1.1em;
  margin-left: 2px;
  vertical-align: -0.15em;
  background: var(--primary);
  animation: caretBlink 1s steps(2, end) infinite;
}

/* Markdown 样式 */
.content h1, .content h2, .content h3 {
  line-height: 1.3;
  margin: 18px 0 10px;
  letter-spacing: -0.01em;
}
.content h1 { font-size: 26px; font-weight: 700; }
.content h2 { font-size: 22px; font-weight: 700; }
.content h3 { font-size: 18px; font-weight: 600; }
.content p { margin: 8px 0; }
.content ul, .content ol { padding-left: 24px; margin: 8px 0; }
.content li { margin: 4px 0; }
.content blockquote {
  border-left: 3px solid var(--primary);
  padding: 6px 14px;
  margin: 12px 0;
  color: var(--text-muted);
  background: var(--primary-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.content code:not(pre code) {
  background: var(--bg-elev);
  padding: 2px 7px;
  border-radius: 6px;
  font-size: 0.9em;
  font-family: var(--font-mono);
  color: var(--accent);
}
.content pre {
  background: #0b0f1f !important;
  padding: 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin: 14px 0;
  border: 1px solid var(--border);
}
.content pre .code-header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 10px 14px 10px 58px;
  background: #111728;
  color: #9aa3c0;
  font-size: 13px;
  font-family: var(--font-mono);
  border-bottom: 1px solid var(--border);
  position: relative;
}
/* mac 风格三个小圆点 */
.content pre .code-header::before {
  content: "";
  position: absolute;
  left: 14px; top: 50%;
  transform: translateY(-50%);
  width: 12px; height: 12px;
  border-radius: 50%;
  background: #ff5f57;
  box-shadow:
    18px 0 0 #febc2e,
    36px 0 0 #28c840;
}
.content pre .copy-code {
  background: transparent;
  border: none;
  color: #9aa3c0;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 13px;
  transition: color 0.15s var(--ease-out), background 0.15s var(--ease-out);
}
.content pre .copy-code:hover { color: #fff; background: rgba(255,255,255,0.08); }
.content pre code {
  display: block;
  padding: 14px 18px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.65;
}
.content table {
  border-collapse: collapse;
  margin: 14px 0;
  width: 100%;
  font-size: 15px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border);
}
.content th, .content td {
  border-bottom: 1px solid var(--border);
  padding: 10px 14px;
  text-align: left;
}
.content tr:last-child td { border-bottom: none; }
.content th { background: var(--bg-soft); font-weight: 600; }
.content a {
  color: var(--primary);
  text-decoration: none;
  border-bottom: 1px dashed var(--primary);
  transition: border-color 0.15s var(--ease-out);
}
.content a:hover { border-bottom-style: solid; }
.content .katex { font-size: 1.05em; }

/* 用户图片附件 */
.attached-images {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 8px;
}
.attached-images img {
  max-width: 220px;
  max-height: 220px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  object-fit: cover;
  transition: transform 0.2s var(--ease-out);
}
.attached-images img:hover { transform: scale(1.02); }

/* 生成的图片 */
.generated-images {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin: 14px 0;
  max-width: 640px;
}
.generated-images figure {
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  animation: scaleIn 0.4s var(--ease-out);
  transition: transform 0.2s var(--ease-out), box-shadow 0.2s var(--ease-out);
}
.generated-images figure:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.generated-images img { width: 100%; height: auto; display: block; }
.generated-images figcaption {
  padding: 8px 10px;
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
}

/* 生成图片加载中 */
.image-loading {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  background: linear-gradient(90deg, var(--bg-soft), var(--bg-elev), var(--bg-soft));
  background-size: 200% 100%;
  animation: shimmer 2.4s linear infinite, fadeIn 0.3s var(--ease-out);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 10px 0;
  font-size: 16px;
}
.spinner {
  width: 20px; height: 20px;
  border: 2.5px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* OCR 提示 */
.ocr-note {
  display: inline-block;
  padding: 6px 10px;
  background: var(--bg-soft);
  border: 1px dashed var(--border);
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 14px;
  margin-top: 6px;
}

/* ================== 输入区 ================== */
.composer {
  border-top: 1px solid var(--border-soft);
  background: color-mix(in srgb, var(--bg-soft) 80%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 14px 24px 18px;
}
.composer-inner {
  max-width: 880px;
  margin: 0 auto;
  display: flex;
  align-items: flex-end;
  gap: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 8px 10px;
  transition: border-color 0.18s var(--ease-out), box-shadow 0.25s var(--ease-out), transform 0.18s var(--ease-out);
}
.composer-inner:focus-within {
  border-color: var(--primary);
  box-shadow: var(--glow-primary);
}
.composer-tools { display: flex; gap: 2px; align-items: center; }
.tool-btn {
  padding: 10px;
  background: transparent;
  border: none;
  color: var(--text-muted);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.15s var(--ease-out), color 0.15s var(--ease-out), transform 0.12s var(--ease-out);
}
.tool-btn:hover { background: var(--bg-elev); color: var(--primary); transform: translateY(-1px); }
.tool-btn:active { transform: scale(0.94); }
.tool-btn.active {
  color: var(--danger);
  background: rgba(248, 113, 113, 0.12);
  animation: glowPulse 1.6s var(--ease-in-out) infinite;
}

.prompt-input {
  flex: 1;
  min-height: 40px;
  max-height: 240px;
  resize: none;
  background: transparent;
  border: none;
  outline: none;
  padding: 10px 6px;
  font-size: var(--font-base);
  line-height: 1.55;
  color: var(--text);
}
.prompt-input::placeholder { color: var(--text-muted); }

.send-btn {
  width: 42px; height: 42px;
  background: linear-gradient(135deg, var(--primary), color-mix(in srgb, var(--primary) 70%, var(--accent)));
  color: #fff;
  border: none;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
  transition: transform 0.15s var(--ease-out), box-shadow 0.15s var(--ease-out), filter 0.15s var(--ease-out), background 0.2s var(--ease-out);
}
.send-btn:hover { transform: translateY(-1px); filter: brightness(1.08); box-shadow: 0 8px 20px rgba(99, 102, 241, 0.5); }
.send-btn:active { transform: scale(0.95); }
.send-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  box-shadow: none;
  filter: grayscale(0.3);
  transform: none;
}
.send-btn.stop {
  background: linear-gradient(135deg, var(--danger), #ef4444);
  box-shadow: 0 4px 14px rgba(248, 113, 113, 0.35);
  animation: glowPulse 1.4s var(--ease-in-out) infinite;
}

.composer-hint {
  max-width: 880px;
  margin: 10px auto 0;
  font-size: 12px;
  color: var(--text-muted);
  text-align: center;
  letter-spacing: 0.01em;
}

.attachments-preview {
  max-width: 880px;
  margin: 0 auto 10px;
  display: flex; gap: 8px; flex-wrap: wrap;
}
.attachments-preview .thumb {
  position: relative;
  width: 80px; height: 80px;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  animation: scaleIn 0.25s var(--ease-out);
  transition: transform 0.18s var(--ease-out), border-color 0.18s var(--ease-out);
}
.attachments-preview .thumb:hover { transform: translateY(-2px); }
.attachments-preview .thumb img { width: 100%; height: 100%; object-fit: cover; }
.attachments-preview .thumb .remove {
  position: absolute; top: 4px; right: 4px;
  width: 22px; height: 22px;
  background: rgba(0,0,0,0.65); color: #fff;
  border: none;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px;
  z-index: 2;
  transition: background 0.15s var(--ease-out), transform 0.15s var(--ease-out);
  opacity: 0;
}
.attachments-preview .thumb:hover .remove { opacity: 1; }
.attachments-preview .thumb .remove:hover { background: var(--danger); transform: scale(1.08); }
.attachments-preview .thumb .status-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  color: #fff;
  font-size: 11px;
  font-weight: 600;
  text-align: center;
  padding: 4px;
  pointer-events: none;
}
.attachments-preview .thumb.processing {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px var(--primary-soft);
}
.attachments-preview .thumb.processing .status-overlay { background: rgba(10, 16, 32, 0.7); }
.attachments-preview .thumb.error {
  border-color: var(--danger);
  box-shadow: 0 0 0 2px rgba(248, 113, 113, 0.2);
}
.attachments-preview .thumb.error .status-overlay { background: rgba(220, 38, 38, 0.78); }
.attachments-preview .thumb.success { border-color: var(--success); }
.attachments-preview .thumb.success .status-overlay { display: none; }
.attachments-preview .thumb .mini-spinner {
  width: 20px; height: 20px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
.attachments-preview .thumb .status-icon { font-size: 22px; line-height: 1; }

/* 附件状态提示条 */
.attachment-status-bar {
  max-width: 880px;
  margin: 0 auto 10px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  display: flex;
  align-items: center;
  gap: 10px;
  animation: fadeSlideUp 0.3s var(--ease-out);
}
.attachment-status-bar.processing {
  background: var(--primary-soft);
  border: 1px solid var(--primary);
  color: var(--text);
}
.attachment-status-bar.error {
  background: rgba(248, 113, 113, 0.1);
  border: 1px solid var(--danger);
  color: var(--danger);
}
.attachment-status-bar[hidden] { display: none !important; }

/* ================== 深度思考块 ================== */
.reasoning-block {
  margin: 6px 0 12px;
  padding: 0;
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  border-radius: var(--radius-sm);
  overflow: hidden;
  animation: fadeSlideUp 0.3s var(--ease-out);
}
.reasoning-block summary {
  padding: 10px 14px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 10px;
  transition: background 0.15s var(--ease-out);
}
.reasoning-block summary:hover { background: color-mix(in srgb, var(--accent) 10%, transparent); }
.reasoning-block summary::-webkit-details-marker { display: none; }
.reasoning-block summary::before {
  content: "";
  width: 0; height: 0;
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  border-left: 5px solid var(--accent);
  transition: transform 0.2s var(--ease-out);
}
.reasoning-block[open] summary::before { transform: rotate(90deg); }
.reasoning-block .reasoning-body {
  padding: 12px 16px 14px;
  font-size: calc(var(--font-base) * 0.92);
  line-height: 1.75;
  color: var(--text-muted);
  word-wrap: break-word;
  overflow-wrap: anywhere;
  max-height: 360px;
  overflow-y: auto;
  border-top: 1px solid color-mix(in srgb, var(--accent) 20%, transparent);
}
.reasoning-block .reasoning-body > *:first-child { margin-top: 0; }
.reasoning-block .reasoning-body > *:last-child { margin-bottom: 0; }
.reasoning-block .reasoning-body p { margin: 6px 0; }
.reasoning-block .reasoning-body h1,
.reasoning-block .reasoning-body h2,
.reasoning-block .reasoning-body h3 {
  font-size: calc(var(--font-base) * 1);
  margin: 10px 0 6px;
  color: var(--text);
}
.reasoning-block .reasoning-body ul,
.reasoning-block .reasoning-body ol { padding-left: 20px; margin: 6px 0; }
.reasoning-block .reasoning-body li { margin: 2px 0; }
.reasoning-block .reasoning-body code:not(pre code) {
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  color: var(--accent);
  padding: 1px 6px;
  border-radius: 5px;
  font-family: var(--font-mono);
  font-size: 0.9em;
}
.reasoning-block .reasoning-body pre {
  background: #0b0f1f !important;
  border-radius: var(--radius-sm);
  margin: 8px 0;
  border: 1px solid var(--border);
  overflow: hidden;
}
.reasoning-block .reasoning-body pre code {
  display: block;
  padding: 10px 14px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: calc(var(--font-base) * 0.82);
  line-height: 1.6;
}
.reasoning-block .reasoning-body blockquote {
  border-left: 2px solid var(--accent);
  padding: 2px 12px;
  margin: 8px 0;
  color: var(--text-muted);
  opacity: 0.9;
}
.reasoning-block .reasoning-body .katex { font-size: 1em; }
.reasoning-block .reasoning-body a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px dashed var(--accent);
}
.reasoning-block.active summary { color: var(--accent); }
.reasoning-pulse {
  display: inline-block;
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--accent);
  animation: pulse 1.2s ease-in-out infinite;
}

/* ================== 图标按钮通用 ================== */
.icon-btn {
  background: transparent;
  border: none;
  color: var(--text);
  padding: 6px;
  border-radius: 8px;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background 0.15s var(--ease-out), color 0.15s var(--ease-out), transform 0.12s var(--ease-out);
}
.icon-btn:hover { background: var(--bg-elev); }
.icon-btn:active { transform: scale(0.92); }

/* ================== 弹窗 ================== */
.modal {
  position: fixed;
  inset: 0;
  display: flex; align-items: center; justify-content: center;
  z-index: 100;
  animation: fadeIn 0.2s var(--ease-out);
}
.modal[hidden] { display: none; }
.modal-backdrop {
  position: absolute; inset: 0;
  background: rgba(4, 8, 20, 0.6);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.modal-panel {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  width: min(640px, 94vw);
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-lg);
  animation: modalIn 0.3s var(--ease-out);
}
.modal-header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border-soft);
  display: flex; align-items: center; justify-content: space-between;
}
.modal-header h2 {
  margin: 0;
  font-size: 20px;
  letter-spacing: -0.01em;
}
.modal-body { padding: 20px 24px; overflow-y: auto; }
.modal-footer {
  padding: 14px 24px;
  border-top: 1px solid var(--border-soft);
  display: flex; justify-content: flex-end; gap: 10px;
}
.form-section { margin-bottom: 24px; }
.form-section h3 {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
}
.form-section .muted { color: var(--text-muted); font-size: 13px; margin: 0 0 10px; }
.form-row {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px;
  padding: 8px 0;
}
.form-row label { font-size: 15px; flex: 0 0 auto; }
.form-row select {
  flex: 1; max-width: 340px;
  padding: 10px 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  cursor: pointer;
  transition: border-color 0.15s var(--ease-out);
}
.form-row select:hover, .form-row select:focus { border-color: var(--primary); outline: none; }
.form-section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 6px;
}
.form-section-header h3 { margin: 0 !important; }
.status-chip {
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.02em;
  border: 1px solid var(--border);
  color: var(--text-muted);
  background: color-mix(in srgb, var(--bg-soft) 60%, transparent);
  transition: background-color 0.2s var(--ease-out), color 0.2s var(--ease-out), border-color 0.2s var(--ease-out);
  white-space: nowrap;
}
.status-chip[data-variant="custom"] {
  color: #a7f3d0;
  border-color: color-mix(in srgb, var(--success) 55%, transparent);
  background: color-mix(in srgb, var(--success) 16%, transparent);
}
[data-theme="light"] .status-chip[data-variant="custom"] {
  color: #047857;
  background: color-mix(in srgb, var(--success) 14%, transparent);
}

.muted.small { font-size: 12px; margin-top: 8px; opacity: 0.85; }

.api-key-field { position: relative; }
.api-key-field .settings-textarea {
  padding-right: 44px;
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}
.settings-textarea.masked {
  -webkit-text-security: disc;
  text-security: disc;
}
.api-key-toggle {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  color: var(--text-muted);
  border-radius: 8px;
  transition: background-color 0.15s var(--ease-out), color 0.15s var(--ease-out);
}
.api-key-toggle:hover {
  background: color-mix(in srgb, var(--text) 8%, transparent);
  color: var(--text);
}

.settings-textarea {
  width: 100%;
  padding: 12px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 14px;
  resize: vertical;
  transition: border-color 0.15s var(--ease-out), box-shadow 0.15s var(--ease-out);
}
.settings-textarea:focus { border-color: var(--primary); outline: none; box-shadow: var(--glow-primary); }

.btn-primary {
  padding: 10px 20px;
  background: linear-gradient(135deg, var(--primary), color-mix(in srgb, var(--primary) 70%, var(--accent)));
  color: #fff;
  border: none;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.3);
  transition: transform 0.15s var(--ease-out), filter 0.15s var(--ease-out), box-shadow 0.15s var(--ease-out);
}
.btn-primary:hover { transform: translateY(-1px); filter: brightness(1.06); box-shadow: 0 8px 20px rgba(99, 102, 241, 0.45); }
.btn-primary:active { transform: scale(0.97); }

.btn-ghost {
  padding: 10px 20px;
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 15px;
  transition: background 0.15s var(--ease-out), border-color 0.15s var(--ease-out);
}
.btn-ghost:hover { background: var(--bg-elev); border-color: var(--text-muted); }

/* ================== Toast ================== */
.toast-container {
  position: fixed;
  top: 24px;
  right: 24px;
  z-index: 200;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.toast {
  padding: 12px 18px;
  border-radius: 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 15px;
  box-shadow: var(--shadow);
  animation: toastIn 0.28s var(--ease-out);
  max-width: 360px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.toast::before {
  content: "";
  width: 4px;
  align-self: stretch;
  background: var(--primary);
  border-radius: 3px;
}
.toast.error { border-color: var(--danger); }
.toast.error::before { background: var(--danger); }
.toast.error { color: var(--danger); }
.toast.success { border-color: var(--success); }
.toast.success::before { background: var(--success); }
.toast.success { color: var(--success); }

/* ================== 响应式 ================== */
.mobile-only { display: none; }
@media (max-width: 820px) {
  .mobile-only { display: inline-flex; }
  .sidebar {
    position: fixed;
    top: 0; bottom: 0; left: 0;
    z-index: 50;
    width: 280px;
    box-shadow: var(--shadow-lg);
  }
  .sidebar.collapsed { margin-left: -300px; }
  .expand-sidebar-btn { display: none; }
  .message-wrap { padding: 8px 18px; }
  .generated-images { grid-template-columns: 1fr; max-width: 100%; }
  .welcome h2 { font-size: 26px; }
  .welcome p { font-size: 15px; }
  .welcome-orb { width: 96px; height: 96px; }
  .composer { padding: 10px 14px 14px; }
  .chat-header { padding: 12px 16px; }
}

/* 滚动条 */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 10px;
  border: 2px solid transparent;
  background-clip: padding-box;
}
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); background-clip: padding-box; }

/* Firefox */
* { scrollbar-width: thin; scrollbar-color: var(--border) transparent; }