/* ==========================================================================
   闪连VPN - 极简问答排障风 (Troubleshooting Diagnostic) 全局样式系统
   设计理念: 极简白底黑字、高对比度、精准工程测量仪器感、交互式网络体检
   ========================================================================== */

:root {
  --bg-primary: #FFFFFF;
  --bg-secondary: #F8FAFC;
  --bg-tertiary: #F1F5F9;
  --bg-card: #FFFFFF;
  --text-main: #0F172A;
  --text-muted: #64748B;
  --text-light: #94A3B8;
  --border-light: #E2E8F0;
  --border-strong: #CBD5E1;
  --border-dark: #0F172A;
  
  /* 诊断状态色彩 */
  --status-danger: #EF4444;
  --status-danger-bg: #FEF2F2;
  --status-danger-border: #FCA5A5;
  --status-success: #10B981;
  --status-success-bg: #ECFDF5;
  --status-success-border: #6EE7B7;
  --status-warning: #F59E0B;
  --status-warning-bg: #FFFBEB;
  --status-info: #0284C7;

  --accent-black: #000000;
  --accent-white: #FFFFFF;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-card: 0 20px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.03);

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;
  
  --container-max: 1180px;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
}

/* 顶部跑马灯通告栏 / 警示广播 */
.alert-topbar {
  background-color: var(--accent-black);
  color: #F8FAFC;
  font-size: 0.85rem;
  padding: 8px 16px;
  text-align: center;
  position: relative;
  z-index: 100;
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.alert-topbar .pulse-dot {
  width: 8px;
  height: 8px;
  background-color: #EF4444;
  border-radius: 50%;
  box-shadow: 0 0 8px #EF4444;
  animation: pulse-ring 1.5s infinite;
}

@keyframes pulse-ring {
  0% { transform: scale(0.9); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.9); opacity: 0.8; }
}

.alert-topbar a {
  color: #38BDF8;
  text-decoration: underline;
  margin-left: 6px;
  font-weight: 600;
}

/* 统一容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

/* 导航栏 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  height: 72px;
  display: flex;
  align-items: center;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.03em;
}

.brand-icon {
  width: 32px;
  height: 32px;
  background: var(--accent-black);
  color: var(--accent-white);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 900;
  font-size: 1.1rem;
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 2px 6px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-light);
  border-radius: 4px;
  color: var(--text-muted);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.92rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-links a:hover, .nav-links a.active {
  color: var(--text-main);
}

.nav-links .kb-link-item {
  color: var(--status-info);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 4px;
}

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

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 0.92rem;
  font-weight: 600;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  font-family: var(--font-sans);
}

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

.btn-primary:hover {
  background: #27272A;
  border-color: #27272A;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: var(--text-main);
  border-color: var(--border-strong);
}

.btn-outline:hover {
  background: var(--bg-tertiary);
  border-color: var(--text-main);
}

.btn-danger {
  background: var(--status-danger);
  color: var(--accent-white);
  border-color: var(--status-danger);
}

.btn-danger:hover {
  background: #DC2626;
}

.btn-lg {
  padding: 14px 28px;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

/* 节标题排版 */
.section-header {
  text-align: center;
  margin-bottom: 48px;
  position: relative;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.25;
  color: var(--text-main);
  margin-bottom: 14px;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto;
}

/* ==========================================================================
   板块 1: 极简问答排障风交互诊断终端 (Hero Diagnostic)
   ========================================================================== */
.hero-diagnostic-section {
  padding: 56px 0 80px;
  position: relative;
}

.diagnostic-wrapper {
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 2px solid var(--border-dark);
  border-radius: var(--radius-xl);
  box-shadow: 0 24px 48px -12px rgba(15, 23, 42, 0.12);
  overflow: hidden;
  position: relative;
}

/* 诊断终端仪器顶栏 */
.terminal-topbar {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-light);
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.terminal-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.control-circle {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1px solid rgba(0,0,0,0.15);
}

.control-circle.red { background: #EF4444; }
.control-circle.yellow { background: #F59E0B; }
.control-circle.green { background: #10B981; }

.terminal-info {
  display: flex;
  align-items: center;
  gap: 16px;
}

.live-indicator {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--status-success);
  font-weight: 600;
}

.live-indicator .dot {
  width: 6px;
  height: 6px;
  background: var(--status-success);
  border-radius: 50%;
  animation: pulse-ring 2s infinite;
}

/* 诊断终端主体 */
.diagnostic-body {
  padding: 36px 32px;
}

.diagnostic-headline {
  text-align: center;
  margin-bottom: 32px;
}

.diagnostic-headline h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 10px;
  color: var(--text-main);
}

.diagnostic-headline p {
  font-size: 1rem;
  color: var(--text-muted);
}

/* 3 个是/否排障问答卡片 */
.questionnaire-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 32px;
}

.question-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  transition: all var(--transition-fast);
}

.question-card:hover {
  border-color: var(--border-strong);
  background: #FFFFFF;
  box-shadow: var(--shadow-sm);
}

.question-content {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.question-index {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  background: var(--text-main);
  color: var(--accent-white);
  width: 28px;
  height: 28px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.question-text {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.4;
}

.question-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* 是/否 单选按钮对 */
.yn-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.btn-yn {
  min-width: 68px;
  padding: 8px 16px;
  font-size: 0.95rem;
  font-weight: 700;
  font-family: var(--font-mono);
  border: 2px solid var(--border-strong);
  background: #FFFFFF;
  color: var(--text-main);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-yn:hover {
  border-color: var(--text-main);
  background: var(--bg-tertiary);
}

/* 选中【是】的高亮报警状态 (痛点命中) */
.btn-yn.selected-yes {
  background: var(--status-danger);
  border-color: var(--status-danger);
  color: #FFFFFF;
  box-shadow: 0 0 12px rgba(239, 68, 68, 0.4);
}

/* 选中【否】的正常状态 */
.btn-yn.selected-no {
  background: var(--accent-black);
  border-color: var(--accent-black);
  color: #FFFFFF;
}

/* 诊断触发按钮区 */
.diagnostic-submit-bar {
  text-align: center;
  padding-top: 10px;
}

.btn-diagnose {
  width: 100%;
  max-width: 420px;
  font-size: 1.1rem;
  font-weight: 700;
  padding: 16px 32px;
  background: var(--accent-black);
  color: var(--accent-white);
  border: 2px solid var(--accent-black);
  border-radius: var(--radius-lg);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-family: var(--font-mono);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-fast);
}

.btn-diagnose:hover {
  background: #27272A;
  border-color: #27272A;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* 诊断扫描中遮罩动画 */
.diagnostic-scanning {
  display: none;
  padding: 40px 20px;
  text-align: center;
}

.scan-radar {
  width: 64px;
  height: 64px;
  border: 3px solid var(--border-light);
  border-top-color: var(--text-main);
  border-radius: 50%;
  margin: 0 auto 20px;
  animation: spin 0.8s linear infinite;
}

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

.scan-status-text {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 6px;
}

.scan-progress-bar {
  max-width: 300px;
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: 3px;
  margin: 12px auto;
  overflow: hidden;
}

.scan-progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent-black);
  transition: width 0.05s linear;
}

/* 诊断报告结果生成卡片 (关键转化漏斗) */
.diagnostic-report-card {
  display: none;
  animation: fadeIn 0.4s ease forwards;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.report-header-banner {
  background: var(--status-danger-bg);
  border: 1px solid var(--status-danger-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.report-badge-score {
  display: flex;
  align-items: center;
  gap: 14px;
}

.danger-icon-box {
  width: 48px;
  height: 48px;
  background: var(--status-danger);
  color: #FFFFFF;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 900;
  flex-shrink: 0;
}

.report-title-text h3 {
  font-size: 1.25rem;
  font-weight: 800;
  color: #991B1B;
  letter-spacing: -0.02em;
}

.report-title-text p {
  font-size: 0.88rem;
  color: #B91C1C;
  font-family: var(--font-mono);
  margin-top: 2px;
}

.report-date-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #B91C1C;
  background: rgba(239, 68, 68, 0.1);
  padding: 4px 8px;
  border-radius: 4px;
  white-space: nowrap;
}

/* 瓶颈清单列表 */
.bottlenecks-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 28px;
}

.bottleneck-item {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-left: 4px solid var(--status-danger);
  border-radius: var(--radius-md);
  padding: 16px 20px;
}

.bottleneck-item.optimal {
  border-left-color: var(--status-success);
}

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

.item-name {
  font-weight: 700;
  font-size: 0.98rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.item-tag-warn {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: #FEE2E2;
  color: #DC2626;
}

.item-solution-box {
  background: var(--bg-secondary);
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 0.88rem;
  color: #334155;
  margin-top: 8px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.sol-label {
  font-weight: 700;
  color: #16A34A;
  font-family: var(--font-mono);
  white-space: nowrap;
}

/* 诊断解药行动呼吁区 (CTA Funnel) */
.report-action-hero {
  background: var(--accent-black);
  color: var(--accent-white);
  border-radius: var(--radius-xl);
  padding: 32px 28px;
  text-align: center;
}

.action-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  background: rgba(255, 255, 255, 0.15);
  padding: 4px 10px;
  border-radius: 4px;
  margin-bottom: 12px;
  letter-spacing: 0.05em;
  color: #38BDF8;
}

.report-action-hero h4 {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 10px;
  letter-spacing: -0.02em;
}

.report-action-hero p {
  color: #CBD5E1;
  font-size: 0.95rem;
  max-width: 580px;
  margin: 0 auto 24px;
}

.action-buttons-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-retest {
  background: transparent;
  color: #94A3B8;
  border: 1px solid #475569;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  cursor: pointer;
}

.btn-retest:hover {
  color: #FFFFFF;
  border-color: #CBD5E1;
}

/* ==========================================================================
   板块 3: 节点延迟与实时状态监控板块 (Node Latency & Status)
   ========================================================================== */
.nodes-section {
  padding: 80px 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.nodes-monitor-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  padding: 28px;
}

.monitor-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 16px;
}

.filter-pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-light);
  color: var(--text-muted);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-btn:hover, .filter-btn.active {
  background: var(--text-main);
  border-color: var(--text-main);
  color: var(--accent-white);
}

.ping-refresh-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 8px 14px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  background: #FFFFFF;
  cursor: pointer;
}

.ping-refresh-btn:hover {
  background: var(--bg-tertiary);
}

/* 节点网格卡片 */
.nodes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}

.node-item-card {
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 16px;
  transition: all var(--transition-fast);
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.node-item-card:hover {
  border-color: var(--text-main);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.node-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.node-region {
  display: flex;
  align-items: center;
  gap: 8px;
}

.node-flag {
  font-size: 1.25rem;
}

.node-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-main);
}

.node-type-badge {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--bg-tertiary);
  color: var(--text-muted);
}

.node-stats-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin: 12px 0;
  padding: 10px 12px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
}

.latency-val {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--status-success);
}

.latency-val.high {
  color: var(--status-warning);
}

.packet-loss-stat {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.node-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 14px;
}

.node-tag {
  font-size: 0.72rem;
  padding: 2px 6px;
  background: #F1F5F9;
  border-radius: 3px;
  color: #475569;
}

.node-card-btn {
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 600;
  text-align: center;
  padding: 8px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  background: #FFFFFF;
  transition: all var(--transition-fast);
}

.node-card-btn:hover {
  background: var(--accent-black);
  color: var(--accent-white);
  border-color: var(--accent-black);
}

/* ==========================================================================
   板块 4: 套餐价格板块与核心优势 (Pricing & Core Features)
   ========================================================================== */
.pricing-section {
  padding: 88px 0;
  position: relative;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  margin-bottom: 64px;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-fast);
}

.pricing-card:hover {
  border-color: var(--border-dark);
  box-shadow: var(--shadow-card);
  transform: translateY(-4px);
}

.pricing-card.featured {
  border: 2px solid var(--border-dark);
  box-shadow: var(--shadow-lg);
}

.badge-featured {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-black);
  color: var(--accent-white);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.plan-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 6px;
}

.plan-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  min-height: 40px;
  margin-bottom: 20px;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-light);
}

.currency-symbol {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
}

.price-number {
  font-size: 2.75rem;
  font-weight: 900;
  letter-spacing: -0.04em;
  color: var(--text-main);
  line-height: 1;
}

.price-period {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.plan-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
  flex-grow: 1;
}

.plan-features-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.88rem;
  color: #334155;
}

.feat-check {
  color: var(--status-success);
  font-weight: 900;
  flex-shrink: 0;
}

/* 核心优势板块 */
.features-section {
  padding: 80px 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.feature-box {
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all var(--transition-fast);
}

.feature-box:hover {
  border-color: var(--text-main);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.feature-icon-badge {
  width: 44px;
  height: 44px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 18px;
}

.feature-box h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 10px;
}

.feature-box p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   板块 5: 常见问题 (FAQ) + 知识库独立入口卡片
   ========================================================================== */
.faq-section {
  padding: 88px 0;
}

.faq-layout {
  display: grid;
  grid-template-columns: 1fr;
  max-width: 820px;
  margin: 0 auto 56px;
  gap: 16px;
}

.faq-item {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  background: #FFFFFF;
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--border-strong);
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 20px 24px;
  background: none;
  border: none;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.faq-toggle-icon {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 400;
  color: var(--text-muted);
  transition: transform var(--transition-fast);
}

.faq-item.open .faq-toggle-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out, padding 0.3s ease;
  background: var(--bg-secondary);
  color: #475569;
  font-size: 0.92rem;
  line-height: 1.7;
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding: 0 24px 20px 24px;
}

/* 知识库独立跳转入口横幅 (不堆积长文，而是独立划定引导卡片) */
.kb-portal-banner {
  background: linear-gradient(135deg, #0F172A 0%, #1E293B 100%);
  color: #FFFFFF;
  border-radius: var(--radius-xl);
  padding: 40px 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
  box-shadow: var(--shadow-card);
}

.kb-portal-content {
  max-width: 600px;
}

.kb-tag-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 3px 8px;
  background: rgba(56, 189, 248, 0.2);
  color: #38BDF8;
  border-radius: 4px;
  margin-bottom: 12px;
  font-weight: 600;
}

.kb-portal-content h3 {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}

.kb-portal-content p {
  color: #94A3B8;
  font-size: 0.95rem;
  line-height: 1.6;
}

.kb-portal-action .btn {
  background: #FFFFFF;
  color: #0F172A;
  border-color: #FFFFFF;
  font-weight: 700;
}

.kb-portal-action .btn:hover {
  background: #F8FAFC;
  transform: translateY(-2px);
}

/* ==========================================================================
   板块 6: 用户评价板块 (User Reviews)
   ========================================================================== */
.reviews-section {
  padding: 88px 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-light);
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 20px;
}

.review-card {
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-fast);
}

.review-card:hover {
  border-color: var(--text-main);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.avatar-initial {
  width: 40px;
  height: 40px;
  background: var(--text-main);
  color: #FFFFFF;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-family: var(--font-mono);
}

.user-meta-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-main);
}

.user-meta-role {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.star-rating {
  color: #F59E0B;
  font-size: 0.85rem;
  margin-bottom: 12px;
}

.review-quote {
  font-size: 0.9rem;
  color: #334155;
  line-height: 1.6;
  margin-bottom: 16px;
  flex-grow: 1;
}

.metric-pill-diff {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-main);
}

/* 页脚 */
.site-footer {
  background: #09090B;
  color: #94A3B8;
  padding: 56px 0 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.88rem;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand h4 {
  color: #FFFFFF;
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.footer-brand p {
  max-width: 340px;
  line-height: 1.6;
}

.footer-col h5 {
  color: #FFFFFF;
  font-size: 0.92rem;
  margin-bottom: 16px;
  font-weight: 600;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  color: #94A3B8;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: #FFFFFF;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: #64748B;
  flex-wrap: wrap;
  gap: 12px;
}

/* 响应式调整 */
@media (max-width: 900px) {
  .nav-links {
    display: none;
  }
  .section-title {
    font-size: 1.75rem;
  }
  .diagnostic-body {
    padding: 24px 16px;
  }
  .question-card {
    flex-direction: column;
    align-items: flex-start;
  }
  .yn-actions {
    width: 100%;
    justify-content: flex-end;
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .footer-top {
    grid-template-columns: 1fr;
  }
  .report-header-banner {
    flex-direction: column;
    align-items: flex-start;
  }
  .kb-portal-banner {
    padding: 28px 20px;
  }
}