/* ==========================================================================
   H3C 网络工程师四级实操题库网站 - 现代化全响应式样式表
   ========================================================================== */

:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --primary-border: #bfdbfe;
  
  --task1-color: #0284c7;
  --task1-bg: #f0f9ff;
  --task1-border: #bae6fd;
  
  --task2-color: #d97706;
  --task2-bg: #fffbeb;
  --task2-border: #fde68a;
  
  --task3-color: #7c3aed;
  --task3-bg: #f5f3ff;
  --task3-border: #ddd6fe;

  --success: #10b981;
  --success-bg: #ecfdf5;
  --danger: #ef4444;
  --danger-bg: #fef2f2;
  --warning: #f59e0b;
  --warning-bg: #fffbeb;

  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-sidebar: #ffffff;
  --bg-code: #0f172a;
  --text-main: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --border-dark: #cbd5e1;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "Fira Code", "Cascadia Code", Consolas, Monaco, "Courier New", monospace;

  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.07), 0 2px 4px -2px rgb(0 0 0 / 0.07);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.08);
  --radius: 12px;
  --radius-sm: 6px;
  --radius-lg: 16px;
}

[data-theme="dark"] {
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-light: #1e293b;
  --primary-border: #2563eb;

  --bg-main: #0b1120;
  --bg-card: #131d31;
  --bg-sidebar: #0f172a;
  --bg-code: #030712;
  --text-main: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #1e293b;
  --border-dark: #334155;

  --task1-bg: #082f49;
  --task1-border: #0284c7;
  --task2-bg: #451a03;
  --task2-border: #d97706;
  --task3-bg: #2e1065;
  --task3-border: #7c3aed;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
}

/* 顶部导航栏 */
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  transition: background-color 0.3s;
}

[data-theme="dark"] .navbar {
  background: rgba(15, 23, 42, 0.85);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
}

.brand-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 20px;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.brand-title {
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.3px;
}

.brand-subtitle {
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 400;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-main);
  transition: all 0.2s ease;
}

.btn:hover {
  background: var(--border);
  border-color: var(--border-dark);
}

.btn-primary {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-hover);
  border-color: var(--primary-hover);
}

.btn-sm {
  padding: 5px 10px;
  font-size: 12px;
}

/* 主容器布局 */
.layout-container {
  display: flex;
  min-height: calc(100vh - 64px);
}

/* 左侧题库导航侧边栏 */
.sidebar {
  width: 380px;
  flex-shrink: 0;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  height: calc(100vh - 64px);
  position: sticky;
  top: 64px;
}

.sidebar-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.search-box {
  position: relative;
  width: 100%;
}

.search-input {
  width: 100%;
  padding: 9px 12px 9px 36px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-main);
  color: var(--text-main);
  font-size: 13.5px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

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

.search-icon {
  position: absolute;
  left: 11px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.filter-chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.filter-chip {
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  background: var(--bg-main);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  transition: all 0.2s;
}

.filter-chip:hover, .filter-chip.active {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary-border);
}

/* 题目列表区域 */
.sidebar-list {
  flex: 1;
  overflow-y: auto;
  padding: 12px 8px;
}

.task-section-title {
  padding: 8px 12px;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.task-count-badge {
  background: var(--border);
  padding: 2px 6px;
  border-radius: 10px;
  font-size: 11px;
}

.question-item {
  padding: 12px 14px;
  margin-bottom: 6px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.18s ease;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.question-item:hover {
  background: var(--bg-main);
  border-color: var(--border);
}

.question-item.active {
  background: var(--primary-light);
  border-color: var(--primary-border);
}

.q-item-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.q-badge {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 4px;
}

.badge-task1 { background: var(--task1-bg); color: var(--task1-color); border: 1px solid var(--task1-border); }
.badge-task2 { background: var(--task2-bg); color: var(--task2-color); border: 1px solid var(--task2-border); }
.badge-task3 { background: var(--task3-bg); color: var(--task3-color); border: 1px solid var(--task3-border); }

.q-score {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.q-item-title {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.4;
}

.q-item-desc {
  font-size: 12px;
  color: var(--text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* 右侧内容主展区 */
.content-area {
  flex: 1;
  overflow-y: auto;
  padding: 32px 40px;
  max-width: 1280px;
  margin: 0 auto;
}

/* 题目卡片头 */
.question-header-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}

.q-meta-badges {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}

.pill {
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 20px;
}

.pill-task {
  background: var(--primary-light);
  color: var(--primary);
  border: 1px solid var(--primary-border);
}

.pill-score {
  background: var(--success-bg);
  color: var(--success);
}

.pill-time {
  background: var(--warning-bg);
  color: var(--warning);
}

.pill-type {
  background: var(--bg-main);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.question-title {
  font-size: 23px;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 10px;
  letter-spacing: -0.4px;
}

.question-desc {
  font-size: 14.5px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* 快速导航与全局面板工具栏 */
.global-panel-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 16px;
  padding: 10px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.quick-nav-bar {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.quick-nav-chip {
  font-size: 12px;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--bg-main);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
  text-decoration: none;
}

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

.toolbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* 通用折叠面板卡片 */
.panel-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.panel-card:hover {
  border-color: var(--border-dark);
}

.panel-header {
  padding: 15px 22px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
  transition: background-color 0.15s ease;
}

.panel-header:hover {
  background: var(--bg-main);
}

.panel-card.collapsed .panel-header {
  border-bottom: none;
}

.panel-card.collapsed .panel-body {
  display: none !important;
}

.panel-header-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.panel-icon {
  font-size: 18px;
}

.panel-title {
  font-size: 15.5px;
  font-weight: 700;
  color: var(--text-main);
}

.panel-header-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.collapse-indicator {
  font-size: 11px;
  color: var(--text-muted);
  transition: transform 0.2s ease;
  display: inline-block;
  margin-left: 4px;
}

.panel-card.collapsed .collapse-indicator {
  transform: rotate(-90deg);
}

.panel-badge {
  font-size: 12px;
  padding: 2px 8px;
  border-radius: 12px;
  background: var(--bg-main);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.panel-body {
  padding: 20px 24px;
}

/* 拓扑图展示与缩放预览 */
.topology-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--bg-main);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px;
  position: relative;
}

.topology-img {
  max-width: 100%;
  max-height: 480px;
  object-fit: contain;
  border-radius: var(--radius-sm);
  cursor: zoom-in;
  transition: transform 0.25s ease;
  box-shadow: var(--shadow-sm);
}

.topology-img:hover {
  transform: scale(1.015);
}

.topology-hint {
  margin-top: 12px;
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
}

/* 数据表格排版 */
.styled-table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 13.5px;
  text-align: left;
}

.styled-table th {
  background: var(--bg-main);
  color: var(--text-secondary);
  font-weight: 700;
  padding: 10px 14px;
  border-bottom: 2px solid var(--border);
  white-space: nowrap;
}

.styled-table td {
  padding: 11px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-main);
}

.styled-table tr:hover td {
  background: var(--bg-main);
}

/* 通信测试指标清单 */
.comm-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 12px;
  margin-top: 12px;
}

.comm-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  background: var(--bg-main);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.comm-card.success {
  border-left: 4px solid var(--success);
}

.comm-card.failed {
  border-left: 4px solid var(--danger);
}

.comm-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.comm-pair {
  font-weight: 700;
  font-size: 14px;
  color: var(--text-main);
}

.comm-tag {
  font-size: 12px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 12px;
}

.comm-tag.success { background: var(--success-bg); color: var(--success); }
.comm-tag.failed { background: var(--danger-bg); color: var(--danger); }

.comm-reason {
  font-size: 12.5px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* 故障根因专项高亮卡片 (任务二) */
.fault-box {
  background: var(--warning-bg);
  border: 1px solid var(--task2-border);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  margin-bottom: 20px;
}

.fault-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 700;
  color: var(--task2-color);
  margin-bottom: 8px;
}

.fault-content {
  font-size: 14px;
  color: var(--text-main);
  line-height: 1.6;
}

.diagnosis-step-list {
  margin-top: 12px;
  padding-left: 20px;
}

.diagnosis-step-list li {
  margin-bottom: 6px;
  font-size: 13.5px;
}

/* 设备配置终端选项卡与代码区 */
.device-tabs {
  display: flex;
  gap: 8px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 12px;
  margin-bottom: 16px;
  overflow-x: auto;
}

.dev-tab-btn {
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-main);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.dev-tab-btn.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.terminal-box {
  background: var(--bg-code);
  border-radius: var(--radius-sm);
  border: 1px solid #1e293b;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.terminal-bar {
  background: #1e293b;
  padding: 8px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid #334155;
}

.terminal-dots {
  display: flex;
  gap: 6px;
}

.dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}

.dot-red { background: #ef4444; }
.dot-yellow { background: #f59e0b; }
.dot-green { background: #10b981; }

.terminal-title {
  font-family: var(--font-mono);
  font-size: 12px;
  color: #94a3b8;
}

.copy-btn-group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.copy-btn {
  background: rgba(255, 255, 255, 0.1);
  color: #e2e8f0;
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.25);
  border-color: rgba(255, 255, 255, 0.4);
}

.copy-btn.btn-pure {
  background: rgba(16, 185, 129, 0.2);
  color: #6ee7b7;
  border-color: rgba(16, 185, 129, 0.4);
  font-weight: 600;
}

.copy-btn.btn-pure:hover {
  background: rgba(16, 185, 129, 0.35);
  border-color: rgba(16, 185, 129, 0.6);
  color: #a7f3d0;
}

.terminal-code {
  padding: 14px 0;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  color: #f8fafc;
  overflow-x: auto;
}

.code-line {
  display: flex;
  padding: 0 16px;
  transition: background-color 0.1s ease;
}

.code-line:hover {
  background: rgba(255, 255, 255, 0.05);
}

.code-line-num {
  min-width: 34px;
  padding-right: 12px;
  color: #475569;
  text-align: right;
  user-select: none;
  font-size: 12px;
}

.code-line-content {
  flex: 1;
  white-space: pre;
}

.code-comment {
  color: #94a3b8;
  font-style: italic;
}

.code-prompt {
  color: #38bdf8;
  font-weight: 500;
}

.code-cmd {
  color: #f8fafc;
  font-weight: 600;
}

.code-keyword {
  color: #a78bfa;
  font-weight: 600;
}

.code-ip {
  color: #34d399;
}

/* 避坑指南高亮盒 */
.tip-box {
  background: #fdf2f8;
  border: 1px solid #fbcfe8;
  border-radius: var(--radius-sm);
  padding: 16px 20px;
}

[data-theme="dark"] .tip-box {
  background: #500724;
  border-color: #831843;
}

.tip-item {
  margin-bottom: 8px;
  font-size: 13.5px;
  color: #831843;
  line-height: 1.6;
}

[data-theme="dark"] .tip-item {
  color: #fbcfe8;
}

/* 模态弹窗 (图片大图放大 & 速查手册) */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(6px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.modal-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-container {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 960px;
  width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: scale(0.95);
  transition: transform 0.25s ease;
}

.modal-backdrop.open .modal-container {
  transform: scale(1);
}

.modal-header {
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 17px;
  font-weight: 700;
}

.modal-close-btn {
  background: none;
  border: none;
  font-size: 20px;
  color: var(--text-secondary);
  cursor: pointer;
}

.modal-body {
  padding: 24px;
  overflow-y: auto;
}

/* Toast 提示 */
.toast-msg {
  position: fixed;
  bottom: 28px;
  right: 28px;
  background: #0f172a;
  color: #f8fafc;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  box-shadow: var(--shadow-lg);
  z-index: 200;
  display: flex;
  align-items: center;
  gap: 8px;
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.toast-msg.show {
  transform: translateY(0);
  opacity: 1;
}

/* 打印样式适配 */
@media print {
  .navbar, .sidebar, .nav-actions, .btn, .copy-btn, .modal-backdrop {
    display: none !important;
  }
  .layout-container {
    display: block !important;
  }
  .content-area {
    padding: 0 !important;
    max-width: 100% !important;
  }
  .panel-card {
    box-shadow: none !important;
    border: 1px solid #ccc !important;
    page-break-inside: avoid;
    margin-bottom: 16px !important;
  }
  .terminal-box {
    background: #f8fafc !important;
    border: 1px solid #ccc !important;
  }
  .terminal-code {
    color: #1e293b !important;
  }
}

/* 移动端响应式布局 */
@media (max-width: 960px) {
  .layout-container {
    flex-direction: column;
  }
  .sidebar {
    width: 100%;
    height: auto;
    position: static;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .content-area {
    padding: 20px 16px;
  }
}