/* 威积分解题 v3 - 双主题（Gemini 浅色默认 + 暗色经典）与流光动效样式表 */

/* 1. 变量系统定义 */

/* 浅色主题（系统默认，参考 Google Gemini 移动端质感） */
:root,
[data-theme="light"] {
  --bg-color: #F8FAFC;
  --bg-gradient: radial-gradient(circle at 50% -10%, rgba(99, 102, 241, 0.08) 0%, #F8FAFC 75%);
  --glass-card: rgba(255, 255, 255, 0.88);
  --glass-card-hover: rgba(255, 255, 255, 0.98);
  --glass-border: rgba(15, 23, 42, 0.08);
  --glass-border-focus: rgba(37, 99, 235, 0.45);
  --card-shadow: 0 10px 30px -4px rgba(15, 23, 42, 0.06), 0 4px 12px -2px rgba(15, 23, 42, 0.03);
  --header-bg: rgba(248, 250, 252, 0.85);
  --bottom-bar-bg: rgba(248, 250, 252, 0.92);
  
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;
  
  --accent-primary: #2563EB;
  --accent-gradient: linear-gradient(135deg, #2563EB 0%, #7C3AED 50%, #DB2777 100%);
  --accent-green: #059669;
  --accent-rose: #E11D48;
  --accent-amber: #D97706;
  
  --input-bg: #FFFFFF;
  --input-border: rgba(15, 23, 42, 0.12);
  --input-text: #0F172A;
  
  --type-tab-bg: rgba(15, 23, 42, 0.05);
  --type-tab-active: #FFFFFF;
  --type-tab-active-text: #2563EB;
  --type-tab-active-shadow: 0 2px 8px rgba(15, 23, 42, 0.08);
  
  --upload-bg: rgba(255, 255, 255, 0.6);
  --upload-border: rgba(15, 23, 42, 0.15);
  
  --user-msg-bg: #EFF6FF;
  --user-msg-border: rgba(37, 99, 235, 0.2);
  --user-msg-text: #1E3A8A;
  
  --chip-bg: rgba(15, 23, 42, 0.05);
  --chip-border: rgba(15, 23, 42, 0.08);
  --chip-text: #334155;
  --chip-hover-bg: rgba(37, 99, 235, 0.1);
  --chip-hover-text: #1D4ED8;
  
  --limit-pill-bg: rgba(37, 99, 235, 0.1);
  --limit-pill-border: rgba(37, 99, 235, 0.25);
  --limit-pill-text: #1D4ED8;
  
  --report-card-border: #2563EB;
  --report-card-bg: rgba(239, 246, 255, 0.6);
  
  --modal-bg: #FFFFFF;
  --modal-content-border: rgba(15, 23, 42, 0.1);
  --modal-shadow: 0 24px 60px rgba(15, 23, 42, 0.16);
  
  --aurora-blob1: rgba(147, 197, 253, 0.55);
  --aurora-blob2: rgba(244, 114, 182, 0.45);
  --aurora-blob3: rgba(110, 231, 183, 0.42);
  
  --scrollbar-track: rgba(15, 23, 42, 0.06);
  --scrollbar-thumb: rgba(15, 23, 42, 0.25);
  --scrollbar-thumb-hover: rgba(15, 23, 42, 0.4);
  
  --katex-color: #0F172A;
  --radius-lg: 22px;
  --radius-md: 14px;
  --radius-sm: 8px;
}

/* 暗色主题（经典保留，100% 还原暗色体系） */
[data-theme="dark"] {
  --bg-color: #080B12;
  --bg-gradient: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.12) 0%, rgba(8, 11, 18, 1) 70%);
  --glass-card: rgba(18, 24, 38, 0.72);
  --glass-card-hover: rgba(24, 32, 50, 0.82);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-border-focus: rgba(99, 102, 241, 0.45);
  --card-shadow: 0 12px 36px 0 rgba(0, 0, 0, 0.4);
  --header-bg: rgba(8, 11, 18, 0.78);
  --bottom-bar-bg: rgba(8, 11, 18, 0.92);
  
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  
  --accent-primary: #6366F1;
  --accent-gradient: linear-gradient(135deg, #6366F1 0%, #8B5CF6 50%, #EC4899 100%);
  --accent-green: #10B981;
  --accent-rose: #F43F5E;
  --accent-amber: #F59E0B;
  
  --input-bg: rgba(10, 14, 23, 0.85);
  --input-border: rgba(255, 255, 255, 0.08);
  --input-text: #FFFFFF;
  
  --type-tab-bg: rgba(10, 14, 23, 0.7);
  --type-tab-active: rgba(99, 102, 241, 0.25);
  --type-tab-active-text: #FFFFFF;
  --type-tab-active-shadow: none;
  
  --upload-bg: rgba(10, 14, 23, 0.4);
  --upload-border: rgba(255, 255, 255, 0.15);
  
  --user-msg-bg: rgba(99, 102, 241, 0.15);
  --user-msg-border: rgba(99, 102, 241, 0.25);
  --user-msg-text: #F1F5F9;
  
  --chip-bg: rgba(255, 255, 255, 0.06);
  --chip-border: rgba(255, 255, 255, 0.1);
  --chip-text: #94A3B8;
  --chip-hover-bg: rgba(99, 102, 241, 0.2);
  --chip-hover-text: #FFFFFF;
  
  --limit-pill-bg: rgba(99, 102, 241, 0.15);
  --limit-pill-border: rgba(99, 102, 241, 0.3);
  --limit-pill-text: #818CF8;
  
  --report-card-border: #1F4E79;
  --report-card-bg: rgba(18, 24, 38, 0.72);
  
  --modal-bg: #0D1322;
  --modal-content-border: rgba(255, 255, 255, 0.08);
  --modal-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
  
  --aurora-blob1: rgba(99, 102, 241, 0.40);
  --aurora-blob2: rgba(168, 85, 247, 0.35);
  --aurora-blob3: rgba(236, 72, 153, 0.30);
  
  --scrollbar-track: rgba(255, 255, 255, 0.06);
  --scrollbar-thumb: rgba(255, 255, 255, 0.25);
  --scrollbar-thumb-hover: rgba(255, 255, 255, 0.45);
  
  --katex-color: #F8FAFC;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 8px;
}

/* 2. 基础重置与布局 */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  background-color: var(--bg-color);
  background-image: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  letter-spacing: -0.015em;
  min-height: 100vh;
  min-height: -webkit-fill-available;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

/* 微信/iOS 键盘防缩放：输入框强制 16px 以上 */
input, select, textarea, button {
  font-family: inherit;
  font-size: 16px !important;
}

/* 全屏流光渐变背景容器 (Aurora Fluid Background) */
.aurora-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  max-width: 100%;
  overflow: hidden;
  pointer-events: none;
  z-index: -1;
  contain: strict;
  clip-path: inset(0);
  opacity: 1;
  transition: opacity 0.4s ease;
}

.aurora-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  -webkit-filter: blur(60px);
  will-change: transform;
  transform: translate3d(0, 0, 0);
  pointer-events: none;
}

.blob-1 {
  width: 260px;
  height: 260px;
  top: 0;
  left: 0;
  background: var(--aurora-blob1);
  animation: auroraFloat1 9s ease-in-out infinite alternate;
}

.blob-2 {
  width: 280px;
  height: 280px;
  top: 25%;
  right: 0;
  background: var(--aurora-blob2);
  animation: auroraFloat2 10s ease-in-out infinite alternate;
}

.blob-3 {
  width: 240px;
  height: 240px;
  bottom: 80px;
  left: 5%;
  background: var(--aurora-blob3);
  animation: auroraFloat3 8s ease-in-out infinite alternate;
}

/* 纯 CSS 3D 变换流光动画（仅驱动 transform，绝不触发 reflow 重排） */
@keyframes auroraFloat1 {
  0% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(45px, 35px, 0) scale(1.15); }
  100% { transform: translate3d(15px, 70px, 0) scale(0.95); }
}

@keyframes auroraFloat2 {
  0% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(-40px, -30px, 0) scale(1.18); }
  100% { transform: translate3d(-20px, 40px, 0) scale(0.92); }
}

@keyframes auroraFloat3 {
  0% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(40px, -30px, 0) scale(1.12); }
  100% { transform: translate3d(20px, 30px, 0) scale(0.90); }
}

/* 动效关闭或系统减弱动效偏好：平滑隐藏流光并停止变换 */
.motion-disabled .aurora-container {
  opacity: 0 !important;
}

.motion-disabled .aurora-blob,
@media (prefers-reduced-motion: reduce) {
  .aurora-blob {
    animation: none !important;
    transform: none !important;
  }
}

/* 页面切后台省电机制：暂停动画 */
.aurora-container.paused .aurora-blob {
  animation-play-state: paused !important;
}

/* 版心容器 */
.app-container {
  width: 100%;
  max-width: 680px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  padding: 0 12px calc(85px + env(safe-area-inset-bottom)) 12px;
}

/* 3. 顶部状态与导航栏（防截断重构） */
.header-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: calc(10px + env(safe-area-inset-top)) 14px 10px 14px;
  background: var(--header-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  transition: background-color 0.25s;
}

.brand-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
  flex-shrink: 0;
}

.brand-sparkle {
  color: var(--accent-primary);
  font-size: 16px;
}

.user-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-secondary);
  white-space: nowrap;
  flex-shrink: 0;
}

.pill-short, .btn-new-short {
  display: none;
}

.pill-full, .btn-new-full {
  display: inline;
}

.limit-pill {
  background: var(--limit-pill-bg);
  color: var(--limit-pill-text);
  padding: 3px 8px;
  border-radius: 9999px;
  font-size: 11px;
  font-weight: 600;
  border: 1px solid var(--limit-pill-border);
  white-space: nowrap;
}

.btn-ghost {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 13px;
  padding: 4px 8px;
  border-radius: 8px;
  transition: all 0.15s;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-ghost:hover {
  color: var(--accent-primary);
  background: rgba(15, 23, 42, 0.04);
}

[data-theme="dark"] .btn-ghost:hover {
  background: rgba(255, 255, 255, 0.06);
}

/* 顶部「更多 ⋯」菜单下拉组件（窄屏收纳核心） */
.more-menu-wrapper {
  position: relative;
  display: inline-block;
  z-index: 110;
}

.btn-more {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 10px;
  font-size: 13px !important;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--type-tab-bg);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-more:hover, .btn-more.active {
  color: var(--text-primary);
  background: var(--chip-border);
  border-color: var(--border-color);
}

.btn-more-icon {
  font-size: 13px;
  line-height: 1;
}

.btn-more-label {
  font-size: 12px;
  line-height: 1;
  letter-spacing: 0.2px;
}

.more-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  width: 230px;
  max-width: calc(100vw - 24px);
  background: var(--modal-bg);
  border: 1px solid var(--modal-content-border);
  border-radius: 18px;
  padding: 14px;
  box-shadow: 0 16px 40px rgba(15, 23, 42, 0.18), 0 2px 6px rgba(15, 23, 42, 0.08);
  z-index: 1000;
  animation: dropdownFadeIn 0.18s ease-out;
}

@keyframes dropdownFadeIn {
  from { opacity: 0; transform: translateY(-6px) scale(0.97); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.dropdown-header {
  padding: 4px 6px 8px 6px;
}

.dropdown-user {
  font-weight: 700;
  font-size: 13px;
  color: var(--text-primary);
  display: block;
}

.dropdown-report-limit {
  font-size: 11px;
  color: var(--text-muted);
  display: block;
  margin-top: 2px;
}

.dropdown-divider {
  height: 1px;
  background: var(--glass-border);
  margin: 8px 0;
}

.dropdown-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 6px;
}

.dropdown-item-label {
  font-size: 13px;
  color: var(--text-secondary);
  font-weight: 500;
}

/* 主题切换胶囊群 */
.theme-switch-pills {
  display: flex;
  background: var(--type-tab-bg);
  padding: 2px;
  border-radius: 9999px;
  border: 1px solid var(--glass-border);
}

.theme-pill-btn {
  border: none;
  background: transparent;
  padding: 3px 8px;
  border-radius: 9999px;
  font-size: 11px !important;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s;
}

.theme-pill-btn.active {
  background: var(--type-tab-active);
  color: var(--type-tab-active-text);
  box-shadow: var(--type-tab-active-shadow);
}

/* 动效开关 Switch */
.toggle-switch-btn {
  width: 42px;
  height: 24px;
  background: var(--chip-border);
  border: 1px solid var(--glass-border);
  border-radius: 9999px;
  position: relative;
  cursor: pointer;
  transition: background-color 0.2s;
  padding: 0;
}

.toggle-switch-btn.active {
  background: var(--accent-primary);
}

.switch-knob {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 18px;
  height: 18px;
  background: #FFFFFF;
  border-radius: 50%;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  transition: transform 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.toggle-switch-btn.active .switch-knob {
  transform: translateX(18px);
}

.dropdown-item-btn {
  width: 100%;
  text-align: left;
  border: none;
  background: none;
  padding: 8px 6px;
  border-radius: 8px;
  font-size: 13px !important;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all 0.15s;
  display: flex;
  align-items: center;
  gap: 8px;
}

.dropdown-item-btn:hover {
  background: var(--type-tab-bg);
  color: var(--text-primary);
}

.dropdown-item-btn.danger {
  color: var(--accent-rose);
}

.dropdown-item-btn.danger:hover {
  background: rgba(244, 63, 94, 0.08);
}

/* 移动端 640px 以下视口优化（防截断与自动紧凑） */
@media screen and (max-width: 640px) {
  .header-bar {
    padding: calc(8px + env(safe-area-inset-top)) 10px 8px 10px;
  }
  .brand-title {
    font-size: 14px;
    gap: 5px;
  }
  .user-badge {
    gap: 6px;
  }
  #studentName {
    display: none; /* 移动端在顶部隐藏文字姓名，收纳在更多菜单内 */
  }
  .pill-full, .btn-new-full {
    display: none;
  }
  .pill-short, .btn-new-short {
    display: inline;
  }
  .limit-pill {
    padding: 2px 6px;
    font-size: 11px;
  }
  .btn-ghost {
    padding: 3px 5px;
    font-size: 12px;
  }
}

/* 4. 卡片与核心交互组件（Google Gemini 风格大圆角） */
.glass-card {
  background: var(--glass-card);
  backdrop-filter: blur(25px) saturate(180%);
  -webkit-backdrop-filter: blur(25px) saturate(180%);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--card-shadow);
  width: 100%;
  box-sizing: border-box;
  transition: background 0.25s, border-color 0.25s, box-shadow 0.25s;
}

/* 登录视图 */
.login-view {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 80vh;
  padding: 12px;
  width: 100%;
}

.login-card {
  max-width: 360px;
  width: 100%;
  text-align: center;
  margin: 0 auto;
}

.login-icon {
  font-size: 42px;
  margin-bottom: 16px;
}

.login-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.login-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.5;
}

.code-input-wrapper {
  position: relative;
  margin-bottom: 20px;
}

.code-input {
  width: 100%;
  padding: 16px;
  text-align: center;
  font-size: 22px !important;
  font-weight: 700;
  letter-spacing: 6px;
  text-transform: uppercase;
  background: var(--input-bg);
  border: 1.5px solid var(--input-border);
  border-radius: 9999px; /* Gemini 胶囊形输入框 */
  color: var(--input-text);
  outline: none;
  transition: all 0.2s;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.04);
}

.code-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

.btn-primary {
  width: 100%;
  padding: 14px;
  background: var(--accent-gradient);
  color: #FFFFFF;
  border: none;
  border-radius: 9999px; /* 胶囊形圆角按钮 */
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 4px 18px rgba(37, 99, 235, 0.35);
  transition: all 0.2s;
}

.btn-primary:active {
  transform: scale(0.98);
  opacity: 0.92;
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* 模式选择 Tabs */
.type-selector {
  display: flex;
  background: var(--type-tab-bg);
  padding: 4px;
  border-radius: 9999px; /* 胶囊形 Tabs */
  margin-bottom: 16px;
  border: 1px solid var(--glass-border);
}

.type-tab {
  flex: 1;
  text-align: center;
  padding: 10px 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  border-radius: 9999px;
  cursor: pointer;
  transition: all 0.2s;
  user-select: none;
}

.type-tab.active {
  background: var(--type-tab-active);
  color: var(--type-tab-active-text);
  box-shadow: var(--type-tab-active-shadow);
  border: 1px solid var(--glass-border);
}

/* 上传与预览区 */
.upload-area {
  border: 1.5px dashed var(--upload-border);
  border-radius: var(--radius-md);
  padding: 22px 16px;
  text-align: center;
  cursor: pointer;
  background: var(--upload-bg);
  transition: all 0.2s;
  margin-bottom: 16px;
}

.upload-area:hover, .upload-area.dragover {
  border-color: var(--accent-primary);
  background: rgba(37, 99, 235, 0.06);
}

.upload-icon {
  font-size: 32px;
  margin-bottom: 8px;
}

.upload-hint {
  font-size: 14px;
  color: var(--text-primary);
  font-weight: 600;
  margin-bottom: 4px;
}

.upload-subhint {
  font-size: 12px;
  color: var(--text-muted);
}

.preview-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 16px;
}

.thumb-item {
  position: relative;
  width: 78px;
  height: 78px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--glass-border);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
}

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

.thumb-del {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 20px;
  height: 20px;
  background: rgba(0, 0, 0, 0.7);
  color: #FFFFFF;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  cursor: pointer;
  border: none;
}

/* 备注输入框 */
.note-textarea {
  width: 100%;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  color: var(--text-primary);
  font-size: 14px !important;
  resize: vertical;
  min-height: 64px;
  outline: none;
  margin-bottom: 16px;
  transition: border-color 0.2s, box-shadow 0.2s;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.03);
}

.note-textarea:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

/* 批改报告操作卡片 */
.report-action-card {
  border-left: 4px solid var(--report-card-border) !important;
  background: var(--report-card-bg) !important;
}

/* 5. 消息流与讲题卡片 */
.chat-stream {
  padding: 12px 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
  min-width: 0;
}

.message-card {
  border-radius: var(--radius-lg);
  padding: 18px;
  line-height: 1.65;
  animation: fadeIn 0.25s ease-out;
  min-width: 0;
  max-width: 100%;
  box-sizing: border-box;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.user-msg-card {
  align-self: flex-end;
  background: var(--user-msg-bg);
  border: 1px solid var(--user-msg-border);
  max-width: 88%;
  color: var(--user-msg-text);
  border-radius: 20px 20px 4px 20px;
  min-width: 0;
  box-sizing: border-box;
}

.assistant-msg-card {
  background: var(--glass-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  width: 100%;
  min-width: 0;
  max-width: 100%;
  box-sizing: border-box;
  border-radius: 4px 20px 20px 20px;
}

.assistant-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--glass-border);
}

.teacher-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
}

.teacher-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
}

/* Markdown 排版与 KaTeX 公式美化 */
.markdown-content {
  word-break: break-word;
  overflow-wrap: break-word;
  width: 100%;
  max-width: 100%;
  min-width: 0;
  box-sizing: border-box;
}

.markdown-content h3 {
  font-size: 16px;
  font-weight: 700;
  margin: 16px 0 8px 0;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
  word-break: break-word;
  overflow-wrap: break-word;
}

.markdown-content h3:first-child {
  margin-top: 0;
}

.markdown-content p {
  margin-bottom: 12px;
  color: var(--text-secondary);
  word-break: break-word;
  overflow-wrap: break-word;
}

.markdown-content ul, .markdown-content ol {
  margin: 0 0 12px 20px;
  color: var(--text-secondary);
  word-break: break-word;
  overflow-wrap: break-word;
}

.markdown-content li {
  margin-bottom: 4px;
  word-break: break-word;
  overflow-wrap: break-word;
}

/* KaTeX 公式对比度与无溢出排版（浅色高对比度深石板黑，暗色亮白色） */
.katex {
  color: var(--katex-color) !important;
  font-size: 1.06em;
}

.katex .mord, .katex .mbin, .katex .mrel, .katex .mopen, .katex .mclose, .katex .mpunct {
  color: var(--katex-color) !important;
}

.katex-mathml {
  position: absolute !important;
  top: 0 !important;
  left: 0 !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: 0 !important;
  overflow: hidden !important;
  clip: rect(1px, 1px, 1px, 1px) !important;
  clip-path: inset(50%) !important;
}

.katex-display-wrapper {
  display: block;
  width: 100%;
  max-width: 100%;
  min-width: 0;
  overflow-x: auto !important;
  overflow-y: hidden !important;
  -webkit-overflow-scrolling: touch;
  margin: 12px 0;
  padding: 6px 0;
  box-sizing: border-box;
}

.katex-display-wrapper .katex-display {
  display: block !important;
  width: max-content !important;
  min-width: 100% !important;
  margin: 0 !important;
  padding: 0 !important;
  overflow: visible !important;
  text-align: center;
}

.katex-display {
  margin: 0 !important;
  padding: 0 !important;
  overflow: visible !important;
  width: max-content !important;
  min-width: 100% !important;
  box-sizing: border-box;
}

/* 优雅公式横向滚动条（触控友好，支持拖动，双主题自适应） */
.katex-display-wrapper::-webkit-scrollbar {
  height: 6px;
}

.katex-display-wrapper::-webkit-scrollbar-track {
  background: var(--scrollbar-track);
  border-radius: 3px;
}

.katex-display-wrapper::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 3px;
}

.katex-display-wrapper::-webkit-scrollbar-thumb:hover {
  background: var(--scrollbar-thumb-hover);
}

.katex-inline-wrapper {
  display: inline-block;
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  vertical-align: middle;
  box-sizing: border-box;
}

/* 6. 底部浮动追问栏 (适配 iPhone 底部安全区与键盘) */
.bottom-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  width: 100%;
  box-sizing: border-box;
  background: var(--bottom-bar-bg);
  backdrop-filter: blur(25px);
  -webkit-backdrop-filter: blur(25px);
  border-top: 1px solid var(--glass-border);
  z-index: 40;
  padding: 8px 12px calc(12px + env(safe-area-inset-bottom)) 12px;
  transition: background-color 0.25s;
}

.bottom-inner {
  max-width: 680px;
  width: 100%;
  margin: 0 auto;
  box-sizing: border-box;
}

.quick-chips-row {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  scrollbar-width: none;
}

.quick-chips-row::-webkit-scrollbar {
  display: none;
}

.chip-btn {
  white-space: nowrap;
  background: var(--chip-bg);
  border: 1px solid var(--chip-border);
  color: var(--chip-text);
  border-radius: 9999px;
  padding: 5px 12px;
  font-size: 12px !important;
  cursor: pointer;
  transition: all 0.15s;
}

.chip-btn:hover, .chip-btn:active {
  background: var(--chip-hover-bg);
  color: var(--chip-hover-text);
  border-color: var(--accent-primary);
}

.chat-input-row {
  display: flex;
  gap: 8px;
  align-items: center;
}

.chat-input {
  flex: 1;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: 9999px;
  padding: 10px 18px;
  color: var(--text-primary);
  outline: none;
  font-size: 15px !important;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.04);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.chat-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.btn-send {
  background: var(--accent-gradient);
  color: #FFFFFF;
  border: none;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(37, 99, 235, 0.3);
  font-size: 16px;
  flex-shrink: 0;
  transition: transform 0.15s;
}

.btn-send:active {
  transform: scale(0.92);
}

/* 7. Loading 与 状态反馈 */
.loading-spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid rgba(15, 23, 42, 0.15);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

[data-theme="dark"] .loading-spinner {
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: #FFFFFF;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.teacher-loading {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px;
  color: var(--text-secondary);
  font-size: 14px;
}

/* 8. 管理端样式 */
.admin-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 12px;
}

.admin-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
  font-size: 14px;
}

.admin-table th, .admin-table td {
  padding: 12px 10px;
  text-align: left;
  border-bottom: 1px solid var(--glass-border);
  white-space: nowrap;
}

.admin-table th {
  color: var(--text-muted);
  font-weight: 600;
}

.status-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 600;
}

.status-active {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.status-disabled {
  background: rgba(244, 63, 94, 0.15);
  color: var(--accent-rose);
  border: 1px solid rgba(244, 63, 94, 0.3);
}

.btn-sm {
  padding: 4px 10px;
  font-size: 12px !important;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: none;
}

.btn-warn {
  background: rgba(244, 63, 94, 0.15);
  color: var(--accent-rose);
  border: 1px solid rgba(244, 63, 94, 0.3);
}

.btn-success {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

/* 9. 弹窗 Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 100;
}

.modal-content {
  background: var(--modal-bg);
  border: 1px solid var(--modal-content-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  max-width: 440px;
  width: 100%;
  box-shadow: var(--modal-shadow);
  color: var(--text-primary);
}

.big-code-display {
  font-size: 32px;
  font-weight: 800;
  letter-spacing: 6px;
  color: var(--accent-primary);
  background: rgba(37, 99, 235, 0.08);
  padding: 16px;
  border-radius: var(--radius-md);
  margin: 16px 0;
  border: 1.5px dashed var(--accent-primary);
  text-align: center;
  user-select: all;
}

/* 10. 表单控件与通用状态组件（v2.4 账号体系） */
.form-group {
  margin-bottom: 14px;
  text-align: left;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.form-input, .form-select {
  width: 100%;
  box-sizing: border-box;
  padding: 11px 14px;
  background: var(--input-bg);
  border: 1.5px solid var(--input-border);
  border-radius: 12px;
  color: var(--text-primary);
  font-size: 14px !important;
  outline: none;
  transition: all 0.2s;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.04);
}

.form-input:focus, .form-select:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.18);
}

.form-select option {
  background: var(--modal-bg);
  color: var(--text-primary);
}

.form-notice {
  padding: 10px 14px;
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: 10px;
  color: #ef4444;
  font-size: 12px;
  font-weight: 600;
  line-height: 1.4;
  margin: 14px 0;
  text-align: left;
}

.form-hint {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 4px;
  line-height: 1.4;
}

.status-pending {
  background: rgba(245, 158, 11, 0.15);
  color: #d97706;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.status-expired {
  background: rgba(100, 116, 139, 0.15);
  color: #64748b;
  border: 1px solid rgba(100, 116, 139, 0.3);
}

.status-soon {
  background: rgba(239, 68, 68, 0.15);
  color: #ef4444;
  border: 1px solid rgba(239, 68, 68, 0.3);
  font-weight: 700;
}

.badge-custom-school {
  background: rgba(245, 158, 11, 0.15);
  color: #d97706;
  border: 1px solid rgba(245, 158, 11, 0.3);
  font-size: 10px;
  padding: 1px 5px;
  border-radius: 4px;
  margin-left: 4px;
  font-weight: 600;
}

/* 管理端多标签导航栏 */
.admin-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
  overflow-x: auto;
  padding-bottom: 4px;
  scrollbar-width: none;
}

.admin-tabs::-webkit-scrollbar {
  display: none;
}

.admin-tab-btn {
  padding: 8px 16px;
  font-size: 13px !important;
  font-weight: 600;
  border-radius: 9999px;
  background: var(--type-tab-bg);
  color: var(--text-secondary);
  border: 1px solid var(--glass-border);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.admin-tab-btn:hover {
  color: var(--text-primary);
}

.admin-tab-btn.active {
  background: var(--accent-gradient);
  color: #FFFFFF;
  border-color: transparent;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

/* ========================================================
   v2.1 历史记录模块组件样式 (完全适配双主题与 360/390 视口)
   ======================================================== */
.history-filter-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
  overflow-x: auto;
  padding-bottom: 4px;
  scrollbar-width: none;
}

.history-filter-bar::-webkit-scrollbar {
  display: none;
}

.history-filter-pill {
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 600;
  border-radius: 9999px;
  background: var(--type-tab-bg);
  color: var(--text-secondary);
  border: 1px solid var(--glass-border);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.history-filter-pill:hover {
  color: var(--text-primary);
  border-color: var(--accent-primary);
}

.history-filter-pill.active {
  background: var(--accent-gradient);
  color: #FFFFFF;
  border-color: transparent;
  box-shadow: 0 3px 10px rgba(37, 99, 235, 0.25);
}

.history-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.history-card {
  display: flex;
  gap: 12px;
  padding: 14px;
  border-radius: var(--radius-md);
  background: var(--glass-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  box-shadow: var(--card-shadow);
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
  min-width: 0;
  box-sizing: border-box;
}

.history-card:hover {
  transform: translateY(-2px);
  border-color: rgba(37, 99, 235, 0.4);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

.history-card:active {
  transform: translateY(0);
}

.history-thumb-wrapper {
  flex-shrink: 0;
  width: 68px;
  height: 68px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--glass-border);
  background: rgba(0, 0, 0, 0.05);
  display: flex;
  align-items: center;
  justify-content: center;
}

.history-thumb-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.history-thumb-placeholder {
  font-size: 24px;
}

.history-card-body {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.history-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  margin-bottom: 4px;
}

.history-card-badges {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.history-type-tag {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 4px;
}

.history-type-tag.draft {
  background: rgba(16, 185, 129, 0.12);
  color: #10b981;
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.history-type-tag.problem {
  background: rgba(59, 130, 246, 0.12);
  color: #3b82f6;
  border: 1px solid rgba(59, 130, 246, 0.25);
}

.history-report-badge {
  font-size: 10px;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 4px;
}

.history-report-badge.ready {
  background: rgba(59, 130, 246, 0.12);
  color: #2563eb;
  border: 1px solid rgba(59, 130, 246, 0.25);
}

.history-report-badge.unlocked {
  background: rgba(16, 185, 129, 0.15);
  color: #059669;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.history-card-time {
  font-size: 11px;
  color: var(--text-muted);
  white-space: nowrap;
  font-family: monospace;
}

.history-card-summary {
  font-size: 13px;
  color: var(--text-primary);
  line-height: 1.45;
  margin-top: 3px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  text-overflow: ellipsis;
  word-break: break-all;
}

.history-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 6px;
  font-size: 11px;
  color: var(--text-secondary);
}

.history-empty-state {
  text-align: center;
  padding: 42px 20px;
  border-radius: var(--radius-lg);
  background: var(--glass-card);
  border: 1px dashed var(--glass-border);
  margin: 16px 0;
}

.history-empty-state .empty-icon {
  font-size: 42px;
  margin-bottom: 12px;
}

.history-empty-state .empty-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.history-empty-state .empty-desc {
  font-size: 13px;
  color: var(--text-secondary);
  max-width: 320px;
  margin: 0 auto;
  line-height: 1.5;
}

/* ========================================================
   管理端 390px/移动端响应式增强 (任务 A: 防表格横向溢出、Tab胶囊滑动)
   ======================================================== */
@media screen and (max-width: 640px) {
  /* A2: Tab 栏防截断，支持平滑横向滑动胶囊 */
  .admin-tabs {
    margin-left: -12px !important;
    margin-right: -12px !important;
    padding-left: 12px !important;
    padding-right: 12px !important;
    padding-bottom: 8px !important;
    gap: 6px !important;
    -webkit-overflow-scrolling: touch;
    scroll-behavior: smooth;
    overflow-x: auto !important;
    white-space: nowrap !important;
  }

  .admin-tab-btn {
    flex-shrink: 0 !important;
    padding: 6px 14px !important;
    font-size: 12px !important;
    border-radius: 9999px !important;
  }

  /* 筛选栏在 390px 视口下自适应换行，避免撑破父容器 */
  .student-filter-bar {
    width: 100% !important;
    gap: 6px !important;
  }

  .student-filter-bar input.form-input {
    width: 100% !important;
    box-sizing: border-box !important;
  }

  .student-filter-bar select.form-select {
    flex: 1 1 calc(50% - 6px) !important;
    min-width: 120px !important;
    box-sizing: border-box !important;
  }

  .student-filter-bar button.btn-primary {
    width: 100% !important;
    margin-top: 4px;
  }

  /* A1: 表格转响应式卡片化布局，首屏完整展现姓名与到期日 */
  .student-table thead,
  .approval-table thead {
    display: none !important;
  }

  .student-table,
  .student-table tbody,
  .approval-table,
  .approval-table tbody {
    display: block !important;
    width: 100% !important;
  }

  /* 学员名册单卡片 (Grid 布局，姓名与到期日、状态首屏醒目呈现) */
  .student-table tr.student-row {
    display: grid !important;
    grid-template-columns: 1fr auto !important;
    grid-template-areas:
      "name status"
      "exp rem"
      "school school"
      "phone usage"
      "actions actions" !important;
    gap: 6px 10px !important;
    background: var(--glass-card-bg, rgba(255, 255, 255, 0.05)) !important;
    border: 1px solid var(--glass-border) !important;
    border-radius: var(--radius-md) !important;
    padding: 12px 14px !important;
    margin-bottom: 12px !important;
    box-shadow: var(--shadow-sm) !important;
    box-sizing: border-box !important;
  }

  .student-table td {
    padding: 0 !important;
    border: none !important;
    white-space: normal !important;
  }

  .student-table td.col-id {
    display: none !important;
  }

  .student-table td.col-name {
    grid-area: name;
    font-size: 15px !important;
    font-weight: 700 !important;
    color: var(--text-primary) !important;
  }

  .student-table td.col-status {
    grid-area: status;
    justify-self: end;
    display: inline-flex !important;
    align-items: center;
  }

  .student-table td.col-exp {
    grid-area: exp;
    font-size: 12px !important;
    color: var(--text-secondary) !important;
  }

  .student-table td.col-exp::before {
    content: "到期日: ";
    color: var(--text-muted);
    font-size: 11px;
  }

  .student-table td.col-rem {
    grid-area: rem;
    justify-self: end;
    font-size: 12px !important;
  }

  .student-table td.col-school {
    grid-area: school;
    font-size: 12px !important;
    color: var(--text-secondary) !important;
    line-height: 1.4 !important;
  }

  .student-table td.col-phone {
    grid-area: phone;
    font-size: 12px !important;
  }

  .student-table td.col-usage {
    grid-area: usage;
    justify-self: end;
    font-size: 11px !important;
    color: var(--text-muted) !important;
  }

  .student-table td.col-actions {
    grid-area: actions;
    display: flex !important;
    flex-wrap: wrap !important;
    gap: 6px !important;
    padding-top: 8px !important;
    margin-top: 4px !important;
    border-top: 1px dashed var(--glass-border) !important;
  }

  .student-table td.col-actions button {
    flex: 1 1 auto !important;
    text-align: center !important;
    padding: 6px 10px !important;
    font-size: 12px !important;
  }

  /* 待审批单卡片 (Grid 布局) */
  .approval-table tr.approval-row {
    display: grid !important;
    grid-template-columns: 1fr auto !important;
    grid-template-areas:
      "name phone"
      "school grade"
      "region time"
      "actions actions" !important;
    gap: 6px 10px !important;
    background: var(--glass-card-bg, rgba(255, 255, 255, 0.05)) !important;
    border: 1px solid var(--glass-border) !important;
    border-radius: var(--radius-md) !important;
    padding: 12px 14px !important;
    margin-bottom: 12px !important;
    box-shadow: var(--shadow-sm) !important;
    box-sizing: border-box !important;
  }

  .approval-table td {
    padding: 0 !important;
    border: none !important;
    white-space: normal !important;
  }

  .approval-table td.col-id {
    display: none !important;
  }

  .approval-table td.col-name {
    grid-area: name;
    font-size: 15px !important;
    font-weight: 700 !important;
    color: var(--text-primary) !important;
  }

  .approval-table td.col-phone {
    grid-area: phone;
    justify-self: end;
    font-size: 12px !important;
  }

  .approval-table td.col-school {
    grid-area: school;
    font-size: 12px !important;
    color: var(--text-secondary) !important;
  }

  .approval-table td.col-grade {
    grid-area: grade;
    justify-self: end;
    font-size: 12px !important;
    color: var(--text-secondary) !important;
  }

  .approval-table td.col-region {
    grid-area: region;
    font-size: 12px !important;
    color: var(--text-muted) !important;
  }

  .approval-table td.col-time {
    grid-area: time;
    justify-self: end;
    font-size: 11px !important;
    color: var(--text-muted) !important;
  }

  .approval-table td.col-actions {
    grid-area: actions;
    display: flex !important;
    gap: 8px !important;
    padding-top: 8px !important;
    margin-top: 4px !important;
    border-top: 1px dashed var(--glass-border) !important;
  }

  .approval-table td.col-actions button {
    flex: 1 1 50% !important;
    padding: 6px 12px !important;
    font-size: 12px !important;
  }
}

/* 教师自测模式常驻横幅 Banner */
.teacher-preview-banner {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1200;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 16px;
  background: linear-gradient(90deg, #f59e0b, #d97706);
  color: #ffffff;
  font-size: 13px;
  font-weight: 600;
  box-shadow: 0 2px 10px rgba(217, 119, 6, 0.25);
  box-sizing: border-box;
}

[data-theme="dark"] .teacher-preview-banner {
  background: linear-gradient(90deg, #b45309, #78350f);
  color: #fef3c7;
  border-bottom: 1px solid rgba(245, 158, 11, 0.3);
}

.teacher-preview-banner .banner-content {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1 1 auto;
}

.teacher-preview-banner .banner-icon {
  font-size: 15px;
  animation: pulse-glow 2s infinite ease-in-out;
}

.teacher-preview-banner .banner-exit-btn {
  background: #ffffff;
  color: #b45309;
  border: none;
  border-radius: 999px;
  padding: 5px 12px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
  box-shadow: 0 2px 5px rgba(0,0,0,0.15);
}

.teacher-preview-banner .banner-exit-btn:hover {
  background: #fef3c7;
  transform: translateY(-1px);
}

[data-theme="dark"] .teacher-preview-banner .banner-exit-btn {
  background: #fef3c7;
  color: #78350f;
}