/**
 * BitzNet (bitz-net.lol) 官方落地页主样式表
 * 架构规范：纵向连续滚动式现代官网 (参考 thepandacloud 结构)
 * 模板：10 虫洞穿梭 | 框架：57 网络架构图 网络节点高亮
 */

:root {
  --bg-primary: #070A13;
  --bg-secondary: #0F172A;
  --bg-card: rgba(15, 23, 42, 0.75);
  --bg-card-hover: rgba(30, 41, 59, 0.85);
  --border-light: rgba(255, 255, 255, 0.08);
  --border-cyan: rgba(0, 240, 255, 0.3);
  --accent-cyan: #00F0FF;
  --accent-blue: #3B82F6;
  --accent-purple: #7C3AED;
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --header-height: 72px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", Consolas, Monaco, monospace;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
}

/* 锚点偏移保障固定导航不遮挡 */
section {
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}

/* 通用容器 */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* 标签与标题 */
.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(0, 240, 255, 0.1);
  border: 1px solid rgba(0, 240, 255, 0.25);
  color: var(--accent-cyan);
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 0.85rem;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.5rem;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 1rem;
}

.section-title .text-gradient {
  background: linear-gradient(135deg, #00F0FF 0%, #3B82F6 50%, #A855F7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

/* 按钮通用规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 0.95rem;
  padding: 0.8rem 1.6rem;
  border-radius: 10px;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.28s cubic-bezier(0.4, 0, 0.2, 1);
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, #00F0FF, #3B82F6);
  color: #070A13;
  box-shadow: 0 4px 20px rgba(0, 240, 255, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 240, 255, 0.55);
  color: #000;
}

.btn-secondary {
  background: rgba(30, 41, 59, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text-primary);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(51, 65, 85, 0.9);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: translateY(-2px);
}

/* ===================================================
   1. 固定顶部导航 (Sticky Navbar)
   =================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 1000;
  background: rgba(7, 10, 19, 0.75);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-light);
  transition: all 0.3s ease;
}

.site-header.scrolled {
  background: rgba(7, 10, 19, 0.92);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.6);
  border-bottom-color: rgba(0, 240, 255, 0.2);
}

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

.brand-logo-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-logo-svg {
  width: 36px;
  height: 36px;
  filter: drop-shadow(0 0 8px rgba(0, 240, 255, 0.5));
}

.brand-name-text {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #FFFFFF 40%, #00F0FF 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s ease;
  position: relative;
  padding: 0.3rem 0;
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent-cyan);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent-cyan);
  border-radius: 2px;
  box-shadow: 0 0 6px var(--accent-cyan);
}

.header-cta-btn {
  padding: 0.55rem 1.25rem;
  font-size: 0.85rem;
  font-weight: 700;
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.6rem;
  cursor: pointer;
  padding: 0.5rem;
}

/* 手机抽屉菜单 */
.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 100%;
  background: rgba(11, 15, 25, 0.98);
  border-bottom: 1px solid var(--border-cyan);
  padding: 1.5rem;
  flex-direction: column;
  gap: 1rem;
  z-index: 999;
}

.mobile-nav-drawer.is-open {
  display: flex;
}

.mobile-nav-link {
  color: var(--text-primary);
  text-decoration: none;
  font-size: 1.05rem;
  font-weight: 600;
  padding: 0.5rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

/* ===================================================
   第 1 区：首页 Hero (#hero) - 模板 10 虫洞穿梭
   =================================================== */
.hero-section {
  position: relative;
  padding-top: calc(var(--header-height) + 4rem);
  padding-bottom: 5rem;
  min-height: 92vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 3rem;
  align-items: center;
  position: relative;
  z-index: 10;
}

.hero-content {
  max-width: 650px;
}

.hero-pill-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(124, 58, 237, 0.15);
  border: 1px solid rgba(124, 58, 237, 0.35);
  color: #C084FC;
  padding: 0.35rem 0.9rem;
  border-radius: 9999px;
  font-size: 0.82rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
}

.hero-title {
  font-size: 3.1rem;
  font-weight: 900;
  line-height: 1.18;
  color: #FFFFFF;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}

.hero-lead-text {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 2rem;
}

.hero-action-group {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
  margin-bottom: 2.25rem;
}

.hero-stats-row {
  display: flex;
  gap: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-light);
}

.hero-stat-item .stat-num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-cyan);
}

.hero-stat-item .stat-label {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Hero 右侧品牌视觉仪表盘卡片 */
.hero-visual-card {
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid var(--border-cyan);
  border-radius: 20px;
  padding: 1.75rem;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.6), 0 0 30px rgba(0, 240, 255, 0.1);
  backdrop-filter: blur(24px);
  position: relative;
}

.hero-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.hero-card-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.card-status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #10B981;
  box-shadow: 0 0 10px #10B981;
}

.hero-telemetry-cluster {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.telemetry-row {
  background: rgba(7, 10, 19, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  padding: 0.75rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.telemetry-node-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.telemetry-node-ping {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: #34D399;
  background: rgba(16, 185, 129, 0.15);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
}

/* ===================================================
   第 2 区：框架 57 · 网络架构图 & 品牌优势 (#architecture)
   =================================================== */
.architecture-section {
  padding: 5rem 0;
  position: relative;
  background: linear-gradient(180deg, rgba(7, 10, 19, 0) 0%, rgba(15, 23, 42, 0.4) 50%, rgba(7, 10, 19, 0) 100%);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
  margin-top: 3.5rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 16px;
  padding: 2rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-cyan);
  transform: translateY(-4px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.4), 0 0 20px rgba(0, 240, 255, 0.1);
}

.feature-icon-box {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(0, 240, 255, 0.15), rgba(124, 58, 237, 0.15));
  border: 1px solid rgba(0, 240, 255, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.65rem;
}

.feature-card p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 4 大精选专题直达卡片 */
.topics-row {
  margin-top: 3.5rem;
}

.topics-heading {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.topic-entry-card {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px;
  padding: 1.35rem;
  text-decoration: none;
  transition: all 0.28s ease;
  display: flex;
  flex-direction: column;
}

.topic-entry-card:hover {
  background: rgba(30, 41, 59, 0.85);
  border-color: var(--accent-cyan);
  transform: translateY(-3px);
}

.topic-badge {
  font-size: 0.72rem;
  color: var(--accent-cyan);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.topic-entry-card h4 {
  font-size: 1rem;
  color: var(--text-primary);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.topic-entry-card p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  flex: 1;
  margin-bottom: 0.85rem;
}

.topic-link-action {
  font-size: 0.82rem;
  color: var(--accent-cyan);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* ===================================================
   第 3 区：官方套餐价格 (#plans)
   =================================================== */
.plans-section {
  padding: 5rem 0;
  position: relative;
}

.pricing-controls {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.billing-switch-wrapper {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  padding: 4px;
  display: flex;
}

.billing-cycle-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 0.55rem 1.4rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  position: relative;
}

.billing-cycle-btn.active {
  background: linear-gradient(135deg, rgba(0, 240, 255, 0.2), rgba(124, 58, 237, 0.2));
  color: var(--accent-cyan);
  box-shadow: 0 0 12px rgba(0, 240, 255, 0.25);
}

.discount-tag {
  display: inline-block;
  background: #EF4444;
  color: #FFF;
  font-size: 0.68rem;
  padding: 1px 5px;
  border-radius: 4px;
  margin-left: 4px;
  font-weight: 700;
}

/* 独家优惠码提示横幅 */
.coupon-banner {
  max-width: 680px;
  margin: 0 auto 3rem;
  background: rgba(124, 58, 237, 0.12);
  border: 1px dashed rgba(124, 58, 237, 0.5);
  border-radius: 12px;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.coupon-info-text {
  font-size: 0.9rem;
  color: #E2E8F0;
}

.coupon-code-pill {
  font-family: var(--font-mono);
  font-weight: 700;
  color: #00F0FF;
  background: rgba(0, 240, 255, 0.15);
  padding: 0.25rem 0.65rem;
  border-radius: 6px;
  border: 1px solid rgba(0, 240, 255, 0.3);
}

.copy-coupon-btn {
  background: #7C3AED;
  color: #FFF;
  border: none;
  border-radius: 6px;
  padding: 0.4rem 0.9rem;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

.copy-coupon-btn:hover {
  background: #6D28D9;
}

/* 套餐卡片网格 */
.plans-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  align-items: stretch;
}

.plan-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 18px;
  padding: 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
  position: relative;
}

.plan-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 45px rgba(0, 0, 0, 0.5);
}

/* 推荐核心访问套餐特色高亮 */
.plan-card.is-featured {
  background: linear-gradient(180deg, rgba(30, 27, 75, 0.8) 0%, rgba(15, 23, 42, 0.9) 100%);
  border: 2px solid var(--accent-cyan);
  box-shadow: 0 0 30px rgba(0, 240, 255, 0.25);
  transform: scale(1.03);
}

.plan-card.is-featured:hover {
  transform: scale(1.03) translateY(-6px);
}

.featured-ribbon {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #00F0FF, #3B82F6);
  color: #070A13;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.2rem 0.85rem;
  border-radius: 9999px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.plan-tier-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.plan-tier-subtitle {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.plan-price-block {
  margin-bottom: 1.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.plan-currency {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

.plan-price-num {
  font-family: var(--font-mono);
  font-size: 2.35rem;
  font-weight: 900;
  color: var(--text-primary);
}

.plan-price-period {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.plan-monthly-equivalent {
  font-size: 0.8rem;
  color: #34D399;
  margin-top: 0.25rem;
}

.plan-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 2rem;
  flex: 1;
}

.plan-feature-item {
  font-size: 0.88rem;
  color: #CBD5E1;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.plan-feature-item .check-icon {
  color: #00F0FF;
  font-size: 1rem;
}

.plan-cta-btn {
  width: 100%;
}

/* ===================================================
   第 4 区：客户端下载与使用教程 (#download / #timeline)
   =================================================== */
.download-section {
  padding: 5rem 0;
  position: relative;
  background: rgba(11, 15, 25, 0.5);
}

.client-matrix-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1.25rem;
  margin-bottom: 4rem;
}

.client-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 14px;
  padding: 1.5rem 1rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  transition: all 0.3s ease;
}

.client-card:hover {
  border-color: var(--accent-cyan);
  background: var(--bg-card-hover);
  transform: translateY(-4px);
}

.client-os-icon {
  font-size: 2.2rem;
  margin-bottom: 0.75rem;
}

.client-os-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.client-os-version {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.client-download-btn {
  width: 100%;
  padding: 0.55rem 0.75rem;
  font-size: 0.82rem;
}

/* 4 步极简使用流程 */
.timeline-stepper {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  position: relative;
  margin-top: 2rem;
}

.step-card {
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px;
  padding: 1.75rem 1.25rem;
  position: relative;
}

.step-number {
  position: absolute;
  top: 1rem;
  right: 1.25rem;
  font-family: var(--font-mono);
  font-size: 1.8rem;
  font-weight: 900;
  color: rgba(0, 240, 255, 0.2);
}

.step-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.step-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===================================================
   第 5 区：原创技术专栏 (#articles)
   =================================================== */
.articles-section {
  padding: 5rem 0;
  position: relative;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.article-showcase-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 16px;
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
  text-decoration: none;
}

.article-showcase-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-cyan);
  transform: translateY(-4px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.4);
}

.article-card-badge {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.75rem;
  color: var(--accent-cyan);
  background: rgba(0, 240, 255, 0.1);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 0.85rem;
  font-weight: 600;
}

.article-showcase-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.45;
  margin-bottom: 0.75rem;
}

.article-showcase-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex: 1;
}

.article-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding-top: 0.85rem;
}

.read-more-text {
  color: var(--accent-cyan);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* ===================================================
   第 6 区：用户评价及反馈 (#feedback)
   =================================================== */
.feedback-section {
  padding: 5rem 0;
  position: relative;
  overflow: hidden;
  background: rgba(11, 15, 25, 0.4);
}

.marquee-container {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin: 2.5rem 0;
  mask-image: linear-gradient(to right, transparent, black 10%, black 90%, transparent);
  -webkit-mask-image: linear-gradient(to right, transparent, black 10%, black 90%, transparent);
}

.marquee-track {
  display: flex;
  gap: 1.5rem;
  width: max-content;
  animation: marqueeScroll 45s linear infinite;
}

.marquee-track.reverse {
  animation: marqueeScrollReverse 45s linear infinite;
}

.marquee-card {
  width: 340px;
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px;
  padding: 1.25rem;
  backdrop-filter: blur(12px);
}

.feedback-user-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.feedback-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: linear-gradient(135deg, #00F0FF, #7C3AED);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.9rem;
  color: #070A13;
}

.feedback-user-name {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-primary);
}

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

.feedback-content-text {
  font-size: 0.85rem;
  color: #CBD5E1;
  line-height: 1.5;
}

@keyframes marqueeScroll {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

@keyframes marqueeScrollReverse {
  from { transform: translateX(-50%); }
  to { transform: translateX(0); }
}

.feedback-action-row {
  text-align: center;
  margin-top: 1.5rem;
}

/* 反馈弹窗 Modal */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

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

.modal-dialog {
  background: #0F172A;
  border: 1px solid var(--border-cyan);
  border-radius: 18px;
  padding: 2rem;
  max-width: 500px;
  width: 100%;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.8);
  position: relative;
}

.modal-close-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
}

.modal-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.modal-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  color: #CBD5E1;
  margin-bottom: 0.4rem;
  font-weight: 600;
}

.form-control {
  width: 100%;
  background: #070A13;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  padding: 0.75rem;
  color: #F8FAFC;
  font-family: inherit;
  font-size: 0.9rem;
}

.form-control:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(0, 240, 255, 0.2);
}

/* ===================================================
   第 7 区：常见问题解答 FAQ (#faq)
   =================================================== */
.faq-section {
  padding: 5rem 0;
  position: relative;
}

.faq-accordion-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.25s ease;
}

.faq-item.is-open {
  border-color: var(--border-cyan);
  background: var(--bg-card-hover);
}

.faq-question-btn {
  width: 100%;
  background: none;
  border: none;
  padding: 1.25rem 1.5rem;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  cursor: pointer;
  gap: 1rem;
}

.faq-icon-arrow {
  font-size: 0.85rem;
  color: var(--accent-cyan);
  transition: transform 0.3s ease;
}

.faq-item.is-open .faq-icon-arrow {
  transform: rotate(180deg);
}

.faq-answer-pane {
  display: none;
  padding: 0 1.5rem 1.25rem;
  font-size: 0.95rem;
  color: #CBD5E1;
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 1rem;
}

.faq-item.is-open .faq-answer-pane {
  display: block;
}

/* ===================================================
   第 8 区：官方页脚 (Footer)
   =================================================== */
.site-footer {
  background: #04060C;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 4.5rem 0 2rem;
  position: relative;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3.5rem;
}

.footer-brand-info p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 1rem 0 1.5rem;
  max-width: 360px;
}

.footer-links-col h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: #FFFFFF;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links-list a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  transition: color 0.2s;
}

.footer-links-list a:hover {
  color: var(--accent-cyan);
}

.footer-bottom-bar {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-bottom-bar a {
  color: var(--text-secondary);
  text-decoration: none;
}

.footer-bottom-bar a:hover {
  color: var(--accent-cyan);
}

/* 吐司提示组件 */
.toast-notice {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: rgba(15, 23, 42, 0.95);
  border: 1px solid var(--accent-cyan);
  color: #FFFFFF;
  padding: 0.75rem 1.25rem;
  border-radius: 8px;
  font-size: 0.88rem;
  font-weight: 600;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
  z-index: 3000;
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.3s ease;
  pointer-events: none;
}

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

/* 平滑滚动浮现 */
.scroll-reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ===================================================
   多端响应式媒体查询
   =================================================== */
@media (max-width: 1440px) {
  .container {
    max-width: 1180px;
  }
}

@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .topics-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .plans-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .client-matrix-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .timeline-stepper {
    grid-template-columns: repeat(2, 1fr);
  }
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .desktop-nav,
  .header-cta-btn {
    display: none;
  }
  .mobile-menu-toggle {
    display: block;
  }
  .hero-title {
    font-size: 2.2rem;
  }
  .section-title {
    font-size: 1.85rem;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .topics-grid {
    grid-template-columns: 1fr;
  }
  .plans-grid {
    grid-template-columns: 1fr;
  }
  .client-matrix-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .timeline-stepper {
    grid-template-columns: 1fr;
  }
  .articles-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

@media (max-width: 428px) {
  .container {
    padding: 0 1rem;
  }
  .hero-title {
    font-size: 1.85rem;
  }
  .hero-stats-row {
    flex-direction: column;
    gap: 1rem;
  }
  .client-matrix-grid {
    grid-template-columns: 1fr;
  }
  .btn {
    width: 100%;
  }
  .hero-action-group {
    flex-direction: column;
    width: 100%;
  }
}

@media (max-width: 375px) {
  .hero-title {
    font-size: 1.65rem;
  }
  .section-title {
    font-size: 1.55rem;
  }
}

@media (max-width: 320px) {
  html {
    font-size: 14px;
  }
}

/* 动效适配无障碍 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .marquee-track {
    animation: none !important;
    transform: none !important;
  }
  .scroll-reveal {
    opacity: 1 !important;
    transform: none !important;
  }
}