/* ===================================================================
   Nice加速机场 - 统一设计系统与核心样式表
   Design System: Deep Dark Space, Cyan/Violet Neon Glow, High Polish
   =================================================================== */

:root {
  --bg-main: #070a12;
  --bg-card: rgba(18, 24, 38, 0.85);
  --bg-card-hover: rgba(26, 35, 55, 0.95);
  --bg-glass: rgba(15, 23, 42, 0.75);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(59, 130, 246, 0.35);
  
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --primary-light: #60a5fa;
  --accent: #8b5cf6;
  --accent-cyan: #06b6d4;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
  --shadow-glow: 0 0 25px rgba(59, 130, 246, 0.25);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.65;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  position: relative;
}

body::before {
  content: "";
  position: fixed;
  top: -150px;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.12) 0%, rgba(139, 92, 246, 0.06) 40%, transparent 70%);
  z-index: -1;
  pointer-events: none;
}

a {
  color: var(--primary-light);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: #93c5fd;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ================= 顶部通告栏 ================= */
.top-announcement {
  background: linear-gradient(90deg, rgba(37, 99, 235, 0.25), rgba(139, 92, 246, 0.25));
  border-bottom: 1px solid var(--border-subtle);
  padding: 8px 16px;
  font-size: 0.85rem;
  text-align: center;
  color: #cbd5e1;
}

.top-announcement .badge {
  background: var(--primary);
  color: #fff;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  margin-right: 8px;
}

/* ================= 顶部导航 ================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(7, 10, 18, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  transition: var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.25rem;
  color: #fff;
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  color: #fff;
  box-shadow: 0 0 16px rgba(59, 130, 246, 0.4);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 6px 0;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: #fff;
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), #2563eb);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.6);
  color: #ffffff;
  transform: translateY(-1px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: #fff;
  transform: translateY(-1px);
}

.btn-glow {
  position: relative;
  overflow: hidden;
}

.btn-glow::after {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(60deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transform: rotate(30deg);
  animation: glowSweep 4s infinite;
}

@keyframes glowSweep {
  0% { transform: translate(-100%, -100%) rotate(30deg); }
  30%, 100% { transform: translate(100%, 100%) rotate(30deg); }
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* ================= 通用 Section 规范 ================= */
.section {
  padding: 80px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 56px auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 14px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.25);
  border-radius: var(--radius-full);
  color: var(--primary-light);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
  line-height: 1.25;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ================= Hero 首屏 ================= */
.hero-section {
  padding: 90px 0 70px 0;
  position: relative;
}

.hero-content {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 50px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.25);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  color: var(--accent-emerald);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-emerald);
  box-shadow: 0 0 10px var(--accent-emerald);
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}

.text-gradient {
  background: linear-gradient(135deg, #60a5fa 0%, #a78bfa 50%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 36px;
  max-width: 600px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-features-list {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.feature-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: #cbd5e1;
}

.feature-pill svg {
  color: var(--accent-emerald);
}

/* 测速模拟面板 */
.speed-test-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.speed-test-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.panel-title {
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.panel-tag {
  font-size: 0.75rem;
  background: rgba(59, 130, 246, 0.15);
  color: var(--primary-light);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

.speed-hero-metric {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 18px;
  text-align: center;
  margin-bottom: 20px;
}

.metric-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.metric-value {
  font-size: 2.2rem;
  font-weight: 800;
  color: #38bdf8;
  font-family: monospace;
}

.node-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 20px;
}

.node-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
}

.node-info {
  display: flex;
  align-items: center;
  gap: 10px;
}

.node-flag {
  font-size: 1.1rem;
}

.node-name {
  font-weight: 600;
  color: #e2e8f0;
}

.node-type {
  font-size: 0.75rem;
  color: var(--text-dim);
  background: rgba(255, 255, 255, 0.06);
  padding: 2px 6px;
  border-radius: 4px;
}

.node-ping {
  font-weight: 700;
  font-family: monospace;
  color: var(--accent-emerald);
}

/* ================= 核心优势 Grid ================= */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.adv-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition);
  position: relative;
}

.adv-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
  background: var(--bg-card-hover);
}

.adv-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: rgba(59, 130, 246, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary-light);
  margin-bottom: 22px;
}

.adv-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
}

.adv-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ================= 套餐价格 ================= */
.pricing-toggle-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 54px;
  height: 28px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(255, 255, 255, 0.15);
  transition: var(--transition);
  border-radius: 34px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 20px;
  width: 20px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  transition: var(--transition);
  border-radius: 50%;
}

input:checked + .slider {
  background-color: var(--primary);
}

input:checked + .slider:before {
  transform: translateX(26px);
}

.toggle-label {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
}

.toggle-discount {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-weight: 700;
  margin-left: 6px;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

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

.pricing-card:hover {
  transform: translateY(-6px);
  border-color: rgba(59, 130, 246, 0.4);
}

.pricing-card.featured {
  border-color: var(--primary);
  background: linear-gradient(180deg, rgba(37, 99, 235, 0.15) 0%, rgba(18, 24, 38, 0.95) 100%);
  box-shadow: 0 0 30px rgba(37, 99, 235, 0.25);
  transform: scale(1.03);
}

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

.popular-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(90deg, var(--primary), var(--accent));
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

.plan-name {
  font-size: 1.3rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  min-height: 42px;
  margin-bottom: 20px;
}

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

.currency {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-light);
  margin-right: 4px;
}

.price-amount {
  font-size: 2.5rem;
  font-weight: 800;
  color: #fff;
  line-height: 1;
}

.price-period {
  font-size: 0.875rem;
  color: var(--text-dim);
  margin-left: 6px;
}

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

.plan-spec-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: #cbd5e1;
}

.plan-spec-item svg {
  color: var(--accent-emerald);
  flex-shrink: 0;
}

/* ================= 适合人群 ================= */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.audience-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 28px;
  text-align: center;
  transition: var(--transition);
}

.audience-card:hover {
  transform: translateY(-4px);
  border-color: rgba(59, 130, 246, 0.3);
}

.audience-icon {
  font-size: 2.2rem;
  margin-bottom: 18px;
}

.audience-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
}

.audience-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ================= 教程快速上手 Tab ================= */
.tutorial-tabs-wrap {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.tutorial-tab {
  padding: 10px 22px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
}

.tutorial-tab:hover, .tutorial-tab.active {
  background: rgba(59, 130, 246, 0.15);
  border-color: var(--primary);
  color: #fff;
}

.tutorial-panel {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 40px;
}

.tutorial-panel.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

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

.step-flow-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 32px;
}

.step-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  padding: 24px;
  position: relative;
}

.step-num {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  margin-bottom: 16px;
}

.step-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
}

.step-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ================= 用户评价 ================= */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.stars {
  color: #fbbf24;
  margin-bottom: 14px;
  font-size: 1rem;
  letter-spacing: 2px;
}

.testimonial-content {
  font-size: 0.95rem;
  color: #cbd5e1;
  line-height: 1.7;
  margin-bottom: 20px;
  font-style: italic;
}

.user-meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #3b82f6, #8b5cf6);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  font-size: 1rem;
}

.user-name {
  font-weight: 700;
  color: #fff;
  font-size: 0.95rem;
}

.user-role {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ================= FAQ 手风琴 ================= */
.faq-list {
  max-width: 880px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item.active {
  border-color: rgba(59, 130, 246, 0.4);
}

.faq-question {
  width: 100%;
  padding: 22px 26px;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.05rem;
  font-weight: 600;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-family: inherit;
}

.faq-icon {
  width: 20px;
  height: 20px;
  transition: transform 0.3s ease;
  color: var(--primary-light);
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
  padding: 0 26px;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 800px;
  padding: 0 26px 24px 26px;
  transition: max-height 0.3s ease-in-out;
}

/* ================= 文章矩阵 / 知识库 ================= */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

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

.article-tag {
  font-size: 0.75rem;
  padding: 3px 10px;
  background: rgba(139, 92, 246, 0.15);
  color: #c084fc;
  border-radius: var(--radius-full);
  font-weight: 600;
  width: fit-content;
  margin-bottom: 14px;
}

.article-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.4;
  margin-bottom: 12px;
}

.article-card:hover .article-title {
  color: var(--primary-light);
}

.article-excerpt {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ================= 底部 CTA Banner ================= */
.cta-banner {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.3) 0%, rgba(139, 92, 246, 0.3) 100%);
  border: 1px solid rgba(59, 130, 246, 0.3);
  border-radius: var(--radius-lg);
  padding: 60px 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.cta-banner h2 {
  font-size: 2.4rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 16px;
}

.cta-banner p {
  font-size: 1.15rem;
  color: #cbd5e1;
  max-width: 680px;
  margin: 0 auto 32px auto;
}

/* ================= 页脚 ================= */
.site-footer {
  background: #05070c;
  border-top: 1px solid var(--border-subtle);
  padding: 64px 0 32px 0;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-dim);
  margin-top: 14px;
  line-height: 1.6;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 18px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

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

.footer-col a {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  padding-top: 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.825rem;
  color: var(--text-dim);
}

/* ================= SEO 文章阅读页专用排版 ================= */
.article-page-wrap {
  padding: 40px 0 80px 0;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--text-dim);
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: #fff;
}

.breadcrumb-separator {
  color: var(--text-dim);
}

.article-header {
  margin-bottom: 36px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border-subtle);
}

.article-main-title {
  font-size: 2.4rem;
  font-weight: 800;
  line-height: 1.3;
  color: #fff;
  margin-bottom: 18px;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.875rem;
  color: var(--text-dim);
  flex-wrap: wrap;
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #cbd5e1;
}

.article-content p {
  margin-bottom: 22px;
}

.article-content h2 {
  font-size: 1.7rem;
  font-weight: 800;
  color: #fff;
  margin: 44px 0 18px 0;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-subtle);
}

.article-content h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #e2e8f0;
  margin: 30px 0 14px 0;
}

.article-content ul, .article-content ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

.article-content li {
  margin-bottom: 8px;
}

.article-content strong {
  color: #fff;
}

.article-content blockquote {
  border-left: 4px solid var(--primary);
  background: rgba(59, 130, 246, 0.08);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
  color: #e2e8f0;
  font-style: italic;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.article-content th, .article-content td {
  padding: 14px 18px;
  border: 1px solid var(--border-subtle);
  font-size: 0.92rem;
  text-align: left;
}

.article-content th {
  background: rgba(255, 255, 255, 0.05);
  color: #fff;
  font-weight: 700;
}

.article-content pre {
  background: #04070f;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 18px;
  overflow-x: auto;
  font-family: monospace;
  font-size: 0.9rem;
  color: #38bdf8;
  margin: 24px 0;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.15), rgba(139, 92, 246, 0.15));
  border: 1px solid rgba(59, 130, 246, 0.3);
  border-radius: var(--radius-md);
  padding: 30px;
  text-align: center;
  margin: 48px 0;
}

.related-articles {
  margin-top: 60px;
  padding-top: 36px;
  border-top: 1px solid var(--border-subtle);
}

.related-title {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 24px;
}

/* ================= 响应式调整 ================= */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .audience-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .testimonials-grid {
    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) {
  .site-nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: #090d16;
    border-bottom: 1px solid var(--border-subtle);
    flex-direction: column;
    padding: 24px;
    gap: 16px;
  }
  .site-nav.active {
    display: flex;
  }
  .nav-toggle {
    display: block;
  }
  .hero-title {
    font-size: 2.2rem;
  }
  .section-title {
    font-size: 1.8rem;
  }
  .advantages-grid,
  .pricing-grid,
  .audience-grid,
  .testimonials-grid,
  .articles-grid,
  .step-flow-grid {
    grid-template-columns: 1fr;
  }
  .pricing-card.featured {
    transform: none;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 14px;
    text-align: center;
  }
}