/* ==========================================================================
   智学伴航·终身教育智能学习支持服务平台 - 核心样式表
   设计原则：高科技质感、深青微光配色、模块化工作台、多端流式自适应
   ========================================================================== */

:root {
  --bg-main: #090d16;
  --bg-surface: #0f172a;
  --bg-surface-elevated: #1e293b;
  --bg-surface-card: rgba(30, 41, 59, 0.7);
  --border-color: rgba(148, 163, 184, 0.14);
  --border-color-active: rgba(56, 189, 248, 0.4);
  
  --primary: #0284c7;
  --primary-light: #38bdf8;
  --primary-glow: rgba(56, 189, 248, 0.2);
  --secondary: #0d9488;
  --secondary-light: #2dd4bf;
  --accent: #f59e0b;
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-sub: #cbd5e1;
  
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-glow: 0 0 20px rgba(56, 189, 248, 0.2);
  
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 全局重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
  -webkit-font-smoothing: antialiased;
}

/* 背景科技星芒网格微光 */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 15% 15%, rgba(2, 132, 199, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 85% 20%, rgba(13, 148, 136, 0.1) 0%, transparent 40%),
    radial-gradient(circle at 50% 85%, rgba(245, 158, 11, 0.05) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* 顶部导航 Header */
.app-header {
  height: 68px;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-logo-box {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  cursor: pointer;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), filter 0.3s ease;
}

.brand-logo-box:hover {
  transform: translateY(-2px) scale(1.05);
  filter: drop-shadow(0 0 12px rgba(56, 189, 248, 0.6));
}

.brand-svg-icon {
  width: 44px;
  height: 44px;
  display: block;
}

.brand-titles h1 {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-tag {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: rgba(56, 189, 248, 0.12);
  color: var(--primary-light);
  border: 1px solid rgba(56, 189, 248, 0.3);
  font-weight: 500;
}

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

.header-status-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.status-pill {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(30, 41, 59, 0.6);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 12px;
  color: var(--text-sub);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--success);
  box-shadow: 0 0 8px var(--success);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.header-action-btn {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 7px 14px;
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.header-action-btn:hover {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--primary-light);
  color: var(--primary-light);
}

.header-action-btn.active {
  background: var(--primary);
  border-color: var(--primary-light);
  color: #fff;
}

/* 学员身份徽章 (Header 右侧) */
.user-profile-badge {
  display: flex;
  align-items: center;
  gap: 10px;
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.8), rgba(15, 23, 42, 0.9));
  border: 1px solid rgba(56, 189, 248, 0.3);
  padding: 4px 12px 4px 6px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25);
}

.user-profile-badge:hover {
  border-color: var(--primary-light);
  background: rgba(56, 189, 248, 0.15);
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.3);
  transform: translateY(-1px);
}

.user-avatar-circle {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  box-shadow: 0 0 10px rgba(56, 189, 248, 0.4);
  flex-shrink: 0;
}

.user-info-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.user-name {
  font-size: 12px;
  font-weight: 700;
  color: #f8fafc;
  white-space: nowrap;
}

.user-switch-hint {
  font-size: 10px;
  color: var(--primary-light);
  white-space: nowrap;
}

/* 演示登录卡片列表 */
.login-student-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
}

.login-student-card:hover {
  border-color: var(--primary-light);
  background: rgba(56, 189, 248, 0.08);
  transform: translateX(3px);
}

.login-student-card.active {
  border-color: var(--primary-light);
  background: rgba(56, 189, 248, 0.12);
  box-shadow: inset 0 0 12px rgba(56, 189, 248, 0.15);
}

.student-card-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.student-card-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 16px;
  flex-shrink: 0;
}

.student-card-title {
  font-size: 14px;
  font-weight: 700;
  color: #f8fafc;
  display: flex;
  align-items: center;
  gap: 8px;
}

.student-card-sub {
  font-size: 12px;
  color: #94a3b8;
  margin-top: 3px;
  line-height: 1.4;
}

/* 导航选项卡 Bar */
.nav-tabs-bar {
  background: rgba(15, 23, 42, 0.6);
  border-bottom: 1px solid var(--border-color);
  padding: 0 24px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  white-space: nowrap;
  scrollbar-width: none;
}

.nav-tabs-bar::-webkit-scrollbar {
  display: none;
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 14px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
}

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

.tab-btn.active {
  color: var(--primary-light);
  border-bottom-color: var(--primary-light);
}

.tab-badge-num {
  font-size: 10px;
  background: rgba(56, 189, 248, 0.2);
  color: var(--primary-light);
  padding: 2px 6px;
  border-radius: var(--radius-full);
}

/* 主内容容器 */
.main-layout {
  max-width: 1440px;
  margin: 0 auto;
  padding: 24px;
}

.tab-pane {
  display: none;
  animation: fadeIn 0.3s ease-in-out;
}

.tab-pane.active {
  display: block;
}

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

/* 通用网格与卡片 */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.grid-workspace {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 24px;
}

.glass-card {
  background: var(--bg-surface-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.glass-card:hover {
  border-color: rgba(56, 189, 248, 0.25);
  box-shadow: var(--shadow-md);
}

.card-header-line {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.card-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

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

/* 多模态排障舱特定样式 */
.case-preset-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 14px;
}

.case-preset-item {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.case-preset-item:hover {
  background: rgba(56, 189, 248, 0.1);
  border-color: var(--primary-light);
  transform: translateX(3px);
}

.case-preset-item.active {
  background: rgba(2, 132, 199, 0.2);
  border-color: var(--primary-light);
}

.case-tag-soft {
  font-size: 11px;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.tag-excel { background: rgba(16, 185, 129, 0.15); color: #34d399; }
.tag-word { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.tag-ppt { background: rgba(245, 158, 11, 0.15); color: #fbbf24; }
.tag-win { background: rgba(168, 85, 247, 0.15); color: #c084fc; }
.tag-net { background: rgba(239, 68, 68, 0.15); color: #f87171; }

.upload-drop-zone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  box-sizing: border-box;
  border: 2px dashed rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-md);
  padding: 24px 16px;
  text-align: center;
  cursor: pointer;
  background: rgba(15, 23, 42, 0.6);
  transition: var(--transition);
}

.upload-drop-zone:hover {
  border-color: var(--primary-light);
  background: rgba(56, 189, 248, 0.08);
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.15);
}

.upload-icon-box {
  width: 48px;
  height: 48px;
  margin-bottom: 10px;
  background: rgba(56, 189, 248, 0.12);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary-light);
  transition: var(--transition);
}

.upload-drop-zone:hover .upload-icon-box {
  transform: scale(1.08);
  background: rgba(56, 189, 248, 0.2);
}

.visual-preview-container {
  background: #020617;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-top: 16px;
  position: relative;
  overflow: hidden;
}

.visual-bounding-box {
  border: 2px solid #ef4444;
  background: rgba(239, 68, 68, 0.12);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  margin-bottom: 12px;
  position: relative;
}

.visual-bounding-tag {
  position: absolute;
  top: -10px;
  left: 10px;
  background: #ef4444;
  color: #fff;
  font-size: 10px;
  font-weight: bold;
  padding: 1px 6px;
  border-radius: var(--radius-sm);
}

.steps-timeline {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: 14px;
}

.step-card {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--primary-light);
  border-radius: var(--radius-md);
  padding: 14px;
}

.step-header {
  font-size: 13px;
  font-weight: 700;
  color: var(--primary-light);
  margin-bottom: 6px;
}

.step-detail {
  font-size: 13px;
  color: var(--text-sub);
  line-height: 1.6;
}

.mnemonic-banner {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.15), rgba(217, 119, 6, 0.05));
  border: 1px solid rgba(245, 158, 11, 0.35);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  margin-top: 18px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.mnemonic-title {
  font-weight: 700;
  color: var(--accent);
  font-size: 13px;
  margin-bottom: 4px;
}

.mnemonic-text {
  font-size: 13px;
  color: #fef3c7;
  line-height: 1.5;
}

/* 启发式问答与聊天舱 */
.chat-window {
  display: flex;
  flex-direction: column;
  height: 580px;
  background: var(--bg-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  overflow: hidden;
}

.chat-history {
  flex: 1;
  padding: 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.message-row {
  display: flex;
  gap: 12px;
  max-width: 82%;
}

.message-row.user {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: bold;
  color: #fff;
  flex-shrink: 0;
}

.message-avatar.ai {
  background: linear-gradient(135deg, var(--secondary), var(--primary));
}

.message-bubble {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  padding: 14px 18px;
  border-radius: var(--radius-md);
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-main);
  white-space: pre-wrap;
}

.message-row.user .message-bubble {
  background: var(--primary);
  border-color: var(--primary-light);
  color: #ffffff;
}

.chat-input-bar {
  padding: 14px 20px;
  background: var(--bg-surface-elevated);
  border-top: 1px solid var(--border-color);
  display: flex;
  gap: 10px;
  align-items: center;
}

.chat-input {
  flex: 1;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px 16px;
  color: var(--text-main);
  font-size: 14px;
  outline: none;
}

.chat-input:focus {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 2px var(--primary-glow);
}

.send-btn {
  background: var(--primary);
  border: none;
  color: #fff;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.send-btn:hover {
  background: var(--primary-light);
}

.quick-chips-row {
  display: flex;
  gap: 8px;
  padding: 10px 20px;
  background: rgba(15, 23, 42, 0.4);
  border-top: 1px solid var(--border-color);
  overflow-x: auto;
  scrollbar-width: none;
}

.quick-chip {
  background: rgba(30, 41, 59, 0.8);
  border: 1px solid var(--border-color);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 11px;
  color: var(--text-sub);
  cursor: pointer;
  white-space: nowrap;
  transition: var(--transition);
}

.quick-chip:hover {
  border-color: var(--primary-light);
  color: var(--primary-light);
}

/* 督学提醒模拟弹框 */
.nudge-card-preview {
  background: #020617;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-top: 14px;
}

.nudge-header {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.nudge-content {
  font-size: 13px;
  line-height: 1.6;
  color: #e2e8f0;
  background: rgba(30, 41, 59, 0.5);
  padding: 12px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--accent);
}

/* 模态框通用 */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  z-index: 999;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-overlay.active {
  display: flex;
}

.modal-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-color-active);
  border-radius: var(--radius-lg);
  max-width: 800px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 20px 40px rgba(0,0,0,0.6);
  padding: 24px;
}

/* 手机端专用底部 Dock 导航栏 */
.mobile-dock-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 60px;
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(16px);
  border-top: 1px solid var(--border-color);
  z-index: 100;
  justify-content: space-around;
  align-items: center;
  padding: 0 8px;
}

.mobile-dock-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 10px;
  font-weight: 600;
  cursor: pointer;
  padding: 6px 0;
  transition: var(--transition);
}

.mobile-dock-item.active {
  color: var(--primary-light);
}

.dock-icon {
  font-size: 16px;
  margin-bottom: 2px;
  font-weight: bold;
}

/* 响应式断点适配 */
@media (max-width: 1024px) {
  .grid-workspace {
    grid-template-columns: 1fr;
  }
  .grid-2 {
    grid-template-columns: 1fr;
  }
  .grid-3 {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .app-header {
    padding: 0 14px;
    height: 60px;
  }
  .brand-titles h1 {
    font-size: 14px;
  }
  .brand-sub {
    display: none;
  }
  .status-pill {
    display: none;
  }
  .nav-tabs-bar {
    display: none; /* 移动端隐藏顶部横栏，改用底部 Dock */
  }
  .main-layout {
    padding: 14px 14px 80px 14px; /* 为底部 Dock 留出安全空间 */
  }
  .mobile-dock-nav {
    display: flex;
  }
  .chat-window {
    height: 480px;
  }
}