/* ==========================================================================
   西部数据 (WestData) 官方落地页样式表
   风格规范: 极简苹果白 (商务、稳定、清爽) + 所有框格纯单线 (1px Solid Black Border, 无重影/无立体硬阴影) + 浅灰底色
   ========================================================================== */

:root {
  --bg-main: #f5f5f7;
  --bg-card: #ffffff;
  --bg-card-subtle: #fafafc;
  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-muted: #86868b;
  --border-black: #000000;
  --border-width: 1px;
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
  --radius-pill: 9999px;
  --accent-color: #0071e3;
  --accent-hover: #0077ed;
  --accent-cyber: #00d26a;
  --accent-warning: #ff9f0a;
  --accent-danger: #ff453a;
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --transition: all 0.2s ease-in-out;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

img, svg {
  display: block;
  max-width: 100%;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* 容器与基础框架 */
.container {
  width: 100%;
  max-width: 1220px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 核心黑框设计类：统一纯单线无重影 */
.black-frame {
  background-color: var(--bg-card);
  border: 1px solid var(--border-black);
  border-radius: var(--radius-lg);
  box-shadow: none;
  transition: var(--transition);
}

.black-frame:hover {
  box-shadow: none;
  transform: translateY(-2px);
}

.black-frame-flat {
  background-color: var(--bg-card);
  border: 1px solid var(--border-black);
  border-radius: var(--radius-lg);
  box-shadow: none;
}

/* 徽章样式：单线 */
.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.82rem;
  font-weight: 600;
  border: 1px solid var(--border-black);
  background-color: #ffffff;
  color: var(--text-primary);
}

.badge-tag.cyber {
  background: #000000;
  color: #00ff88;
  border-color: #000000;
}

.badge-tag.live-pulse::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #00d26a;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.9; }
  70% { transform: scale(1.2); opacity: 0.4; }
  100% { transform: scale(0.95); opacity: 0.9; }
}

/* 顶部导航 Header: 纯单线 */
.site-header {
  position: sticky;
  top: 16px;
  z-index: 1000;
  margin-bottom: 32px;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-black);
  border-radius: var(--radius-pill);
  box-shadow: none;
}

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

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border-black);
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.brand-title span.sub {
  font-size: 0.8rem;
  font-weight: 500;
  background: #000000;
  color: #ffffff;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
}

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

.nav-link {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--text-primary);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-size: 0.92rem;
  font-weight: 700;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-black);
  transition: var(--transition);
  text-align: center;
  white-space: nowrap;
  box-shadow: none;
}

.btn-primary {
  background-color: #000000;
  color: #ffffff;
  box-shadow: none;
}

.btn-primary:hover {
  background-color: #222222;
  box-shadow: none;
  transform: translateY(-1px);
  color: #00ff88;
}

.btn-secondary {
  background-color: #ffffff;
  color: var(--text-primary);
  box-shadow: none;
}

.btn-secondary:hover {
  background-color: #f0f0f2;
}

.btn-sm {
  padding: 6px 14px;
  font-size: 0.85rem;
}

/* ==========================================================================
   指令3: H1 Hero Section
   ========================================================================== */
.hero-section {
  padding: 40px 0 60px;
  text-align: center;
}

.hero-box {
  padding: 56px 36px;
  background: #ffffff;
  border: 1px solid #000000;
  position: relative;
  overflow: hidden;
  box-shadow: none;
}

.hero-tag-bar {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

h1.hero-h1 {
  font-size: 3.2rem;
  font-weight: 900;
  letter-spacing: -1.5px;
  line-height: 1.15;
  margin-bottom: 20px;
  color: #000000;
}

h1.hero-h1 span.highlight {
  background: linear-gradient(180deg, transparent 65%, #ffeb3b 65%);
  padding: 0 6px;
  display: inline-block;
}

.hero-desc {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 820px;
  margin: 0 auto 36px;
  line-height: 1.6;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-cta-btn {
  font-size: 1.15rem;
  padding: 16px 38px;
  background: #000000;
  color: #ffffff;
  border: 1px solid #000000;
  box-shadow: none;
}

.hero-cta-btn:hover {
  background: #1a1a1a;
  box-shadow: none;
  transform: translateY(-2px);
}

.hero-feature-pills {
  display: flex;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  padding-top: 24px;
  border-top: 1px dashed #000000;
}

.feature-pill-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
}

.feature-pill-item svg {
  width: 18px;
  height: 18px;
  color: #000000;
}

/* ==========================================================================
   指令4: H2 套餐内容 (动态并排可滑动，单线框)
   ========================================================================== */
.pricing-section {
  padding: 40px 0 60px;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 28px;
  flex-wrap: wrap;
  gap: 16px;
}

.section-head h2 {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.8px;
  color: #000000;
}

.section-subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-top: 6px;
}

.slider-controls {
  display: none;
  align-items: center;
  gap: 10px;
}

.slider-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid #000000;
  background: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: none;
  transition: var(--transition);
}

.slider-btn:hover {
  background: #000000;
  color: #ffffff;
  box-shadow: none;
}

.pricing-slider-wrap {
  position: relative;
  overflow: visible;
  padding: 12px 0 16px 0;
}

/* 4个套餐卡片桌面端全部同框并排 */
.pricing-track {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  width: 100%;
}

.pricing-card {
  width: 100%;
  background: #ffffff;
  border: 1px solid #000000;
  border-radius: var(--radius-lg);
  padding: 24px 18px;
  display: flex;
  flex-direction: column;
  box-shadow: none;
  transition: var(--transition);
  position: relative;
}

.pricing-card:hover {
  box-shadow: none;
  transform: translateY(-2px);
  border-color: #000000;
}

.pricing-card.featured {
  background: #ffffff;
  border: 1px solid #000000;
  box-shadow: none;
}

.pricing-badge-popular {
  display: inline-flex;
  align-items: center;
  background: #000000;
  color: #ff9f0a;
  border: 1px solid #000000;
  font-size: 0.68rem;
  font-weight: 800;
  padding: 2px 7px;
  border-radius: var(--radius-pill);
  letter-spacing: 0.2px;
  white-space: nowrap;
}

.pricing-card-header {
  border-bottom: 1px solid #e5e5ea;
  padding-bottom: 14px;
  margin-bottom: 18px;
}

.pricing-header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
  gap: 6px;
}

.plan-name {
  font-size: 1.18rem;
  font-weight: 800;
  margin-bottom: 0;
  color: #000000;
  white-space: nowrap;
}

.plan-traffic {
  font-size: 0.8rem;
  font-weight: 700;
  color: #0071e3;
  display: inline-block;
  background: #e8f2ff;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid #000000;
  white-space: nowrap;
}

.plan-price-box {
  margin: 14px 0 4px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.plan-currency {
  font-size: 1.3rem;
  font-weight: 700;
  color: #000000;
}

.plan-amount {
  font-size: 2.5rem;
  font-weight: 900;
  letter-spacing: -1px;
  line-height: 1;
  color: #000000;
}

.plan-period {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.plan-features {
  list-style: none;
  margin-bottom: 22px;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.plan-features li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 0.84rem;
  color: var(--text-primary);
  font-weight: 500;
  line-height: 1.4;
}

.plan-features li svg {
  width: 15px;
  height: 15px;
  color: #00d26a;
  flex-shrink: 0;
  margin-top: 3px;
}

.plan-cta {
  width: 100%;
  padding: 10px;
  font-size: 0.9rem;
}

/* 屏幕在 992px 以下时启用横向滑动 */
@media (max-width: 992px) {
  .slider-controls {
    display: flex;
  }
  .pricing-slider-wrap {
    overflow: hidden;
    padding: 12px 4px 16px 4px;
  }
  .pricing-track {
    display: flex;
    grid-template-columns: none;
    overflow-x: auto;
    scroll-behavior: smooth;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding-bottom: 8px;
  }
  .pricing-track::-webkit-scrollbar {
    display: none;
  }
  .pricing-card {
    flex: 0 0 280px;
    width: 280px;
  }
}

/* ==========================================================================
   指令5: H3 科技感文章流 (浅灰背景 + 单线框)
   ========================================================================== */
.articles-tech-section {
  padding: 40px 0 60px;
}

.tech-stream-container {
  border: 1px solid #000000;
  border-radius: var(--radius-lg);
  background: #eceef2;
  color: #1d1d1f;
  box-shadow: none;
  overflow: hidden;
}

.tech-terminal-header {
  background: #e2e5eb;
  border-bottom: 1px solid #000000;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.tech-dots {
  display: flex;
  gap: 8px;
}

.tech-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 1px solid rgba(0,0,0,0.25);
}

.tech-dot.red { background: #ff5f56; }
.tech-dot.yellow { background: #ffbd2e; }
.tech-dot.green { background: #27c93f; }

.tech-terminal-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #000000;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.tech-stream-window {
  height: 480px;
  overflow-y: hidden;
  position: relative;
  padding: 16px 20px;
  background: #eceef2;
}

.tech-stream-content {
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.tech-article-card {
  background: #ffffff;
  border: 1px solid #000000;
  border-radius: var(--radius-md);
  padding: 18px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  transition: var(--transition);
  position: relative;
  box-shadow: none;
}

.tech-article-card:hover {
  border-color: #000000;
  background: #ffffff;
  transform: translateX(4px);
  box-shadow: none;
}

.tech-article-meta {
  flex: 1;
}

.tech-article-tags {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}

.tech-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 4px;
  background: #eef4ff;
  color: #0066cc;
  border: 1px solid #000000;
  font-weight: 700;
}

.tech-badge.green {
  background: #e8f8ee;
  color: #00873e;
  border: 1px solid #000000;
  font-weight: 700;
}

.tech-time {
  font-size: 0.78rem;
  color: #6e6e73;
  font-family: var(--font-mono);
  font-weight: 600;
}

.tech-article-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: #000000;
  margin-bottom: 6px;
  transition: var(--transition);
}

.tech-article-card:hover .tech-article-title {
  color: #0071e3;
}

.tech-article-excerpt {
  font-size: 0.88rem;
  color: #555558;
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.tech-article-action {
  flex-shrink: 0;
}

.tech-read-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  background: #000000;
  color: #ffffff;
  border: 1px solid #000000;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 700;
  transition: var(--transition);
  box-shadow: none;
}

.tech-article-card:hover .tech-read-btn {
  background: #0071e3;
  color: #ffffff;
  border-color: #0071e3;
  box-shadow: none;
}

.tech-stream-control-bar {
  background: #e2e5eb;
  border-top: 1px solid #000000;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: #555558;
  font-weight: 600;
}

.tech-stream-nav-btns {
  display: flex;
  gap: 8px;
}

.tech-btn-mini {
  padding: 4px 12px;
  background: #ffffff;
  color: #000000;
  border: 1px solid #000000;
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: none;
  transition: var(--transition);
}

.tech-btn-mini:hover {
  background: #000000;
  color: #ffffff;
}

/* ==========================================================================
   指令6: H4 用户评价 (自动跳转) + 节点测速 (自动刷新) - 纯单线框
   ========================================================================== */
.dual-dashboard-section {
  padding: 40px 0 60px;
}

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

/* 左侧：自动跳转用户评价 */
.reviews-dashboard {
  padding: 30px 26px;
  display: flex;
  flex-direction: column;
  border: 1px solid #000000;
}

.reviews-slider-box {
  margin: 20px 0;
  min-height: 220px;
  position: relative;
}

.review-slide {
  display: none;
  animation: fadeIn 0.4s ease-in-out;
}

.review-slide.active {
  display: block;
}

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

.review-stars {
  display: flex;
  gap: 4px;
  color: #ff9f0a;
  margin-bottom: 12px;
}

.review-text {
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-primary);
  line-height: 1.6;
  margin-bottom: 20px;
  font-style: italic;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid #000000;
  background: #e5e5ea;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #000000;
}

.author-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
}

.author-info p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.reviews-nav-indicators {
  display: flex;
  gap: 8px;
  margin-top: auto;
  align-items: center;
}

.review-indicator-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1px solid #000000;
  background: #ffffff;
  cursor: pointer;
  transition: var(--transition);
}

.review-indicator-dot.active {
  background: #000000;
  width: 24px;
  border-radius: var(--radius-pill);
}

/* 右侧：自动刷新节点测速 */
.speed-monitor-dashboard {
  padding: 30px 26px;
  display: flex;
  flex-direction: column;
  border: 1px solid #000000;
}

.monitor-head-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.monitor-timer-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.timer-countdown {
  display: inline-block;
  font-weight: 700;
  color: #0071e3;
}

.node-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 20px;
}

.node-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--bg-card-subtle);
  border: 1px solid #000000;
  border-radius: var(--radius-md);
  box-shadow: none;
  transition: var(--transition);
}

.node-item:hover {
  background: #ffffff;
  box-shadow: none;
}

.node-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.node-flag {
  font-size: 1.2rem;
}

.node-details h4 {
  font-size: 0.9rem;
  font-weight: 700;
}

.node-details span {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-family: var(--font-mono);
}

.node-metrics {
  display: flex;
  align-items: center;
  gap: 16px;
  text-align: right;
  font-family: var(--font-mono);
}

.metric-ping {
  font-size: 0.95rem;
  font-weight: 800;
  color: #00a854;
}

.metric-speed {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* ==========================================================================
   指令7: H5 常见问题 FAQ (动态并排，纯单线)
   ========================================================================== */
.faq-section {
  padding: 40px 0 60px;
}

.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.faq-card {
  padding: 24px;
  border: 1px solid #000000;
  border-radius: var(--radius-lg);
  background: #ffffff;
  box-shadow: none;
  transition: var(--transition);
}

.faq-card:hover {
  box-shadow: none;
  transform: translateY(-2px);
}

.faq-card h5 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 12px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  color: #000000;
}

.faq-q-mark {
  background: #000000;
  color: #ffffff;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  flex-shrink: 0;
  margin-top: 2px;
}

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

/* ==========================================================================
   指令8: H6 所有设备都将受到保护 (单线框)
   ========================================================================== */
.security-section {
  padding: 40px 0 70px;
}

.security-box {
  padding: 44px 36px;
  background: #ffffff;
  border: 1px solid #000000;
  position: relative;
  overflow: hidden;
  box-shadow: none;
}

.security-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 36px;
}

.security-header h6 {
  font-size: 1.9rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 12px;
  color: #000000;
}

.security-header p {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

.device-platforms-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
  margin-bottom: 36px;
}

.device-card {
  padding: 20px 14px;
  text-align: center;
  background: var(--bg-card-subtle);
  border: 1px solid #000000;
  border-radius: var(--radius-md);
  box-shadow: none;
  transition: var(--transition);
}

.device-card:hover {
  background: #000000;
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: none;
}

.device-icon {
  font-size: 2rem;
  margin-bottom: 8px;
}

.device-name {
  font-size: 0.88rem;
  font-weight: 700;
}

.device-client {
  font-size: 0.72rem;
  color: var(--text-muted);
}

.device-card:hover .device-client {
  color: #a1a1a6;
}

.security-features-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  border-top: 1px dashed #000000;
  padding-top: 30px;
}

.sec-feat-item {
  display: flex;
  gap: 14px;
}

.sec-feat-icon {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid #000000;
  background: #f0f0f2;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.sec-feat-text h4 {
  font-size: 0.98rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.sec-feat-text p {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ==========================================================================
   文章详情页专有样式 (Article Pages - 纯单线)
   ========================================================================== */
.article-page-body {
  padding: 30px 0 80px;
}

.breadcrumb-nav {
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.breadcrumb-nav a:hover {
  color: #000000;
  text-decoration: underline;
}

.article-content-box {
  padding: 48px 42px;
  background: #ffffff;
  border: 1px solid #000000;
  box-shadow: none;
}

.article-header {
  border-bottom: 1px solid #000000;
  padding-bottom: 24px;
  margin-bottom: 32px;
}

.article-header h1 {
  font-size: 2.3rem;
  font-weight: 800;
  letter-spacing: -0.8px;
  margin-bottom: 16px;
  line-height: 1.25;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  flex-wrap: wrap;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #2c2c2e;
}

.article-body h2 {
  font-size: 1.6rem;
  font-weight: 800;
  margin: 36px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid #000000;
  color: #000000;
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 28px 0 12px;
  color: #111111;
}

.article-body p {
  margin-bottom: 20px;
}

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

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

.article-callout {
  margin: 28px 0;
  padding: 20px 24px;
  background: #fbfbfd;
  border: 1px solid #000000;
  border-radius: var(--radius-md);
  box-shadow: none;
}

.article-callout-title {
  font-weight: 800;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-cta-banner {
  margin: 40px 0;
  padding: 32px;
  background: #000000;
  color: #ffffff;
  border-radius: var(--radius-lg);
  text-align: center;
  border: 1px solid #000000;
  box-shadow: none;
}

.article-cta-banner h3 {
  color: #ffffff;
  font-size: 1.6rem;
  margin-bottom: 10px;
}

.article-cta-banner p {
  color: #a1a1a6;
  max-width: 600px;
  margin: 0 auto 20px;
}

.article-related-box {
  margin-top: 50px;
  padding-top: 30px;
  border-top: 1px solid #000000;
}

.article-related-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 16px;
}

.related-link-card {
  padding: 16px;
  border: 1px solid #000000;
  border-radius: var(--radius-md);
  background: #fafafc;
  box-shadow: none;
  transition: var(--transition);
}

.related-link-card:hover {
  background: #ffffff;
  box-shadow: none;
  transform: translateY(-2px);
}

/* ==========================================================================
   底部 Footer (纯单线)
   ========================================================================== */
.site-footer {
  margin-top: 40px;
  padding: 50px 0 30px;
  background: #ffffff;
  border-top: 1px solid #000000;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand h3 {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-col h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: #000000;
}

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

.footer-links a {
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.footer-links a:hover {
  color: #000000;
  text-decoration: underline;
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid #e5e5ea;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 12px;
}

/* 响应式调整 */
@media (max-width: 992px) {
  h1.hero-h1 { font-size: 2.5rem; }
  .dual-grid, .faq-grid { grid-template-columns: 1fr; }
  .device-platforms-grid { grid-template-columns: repeat(3, 1fr); }
  .security-features-row { grid-template-columns: 1fr; }
  .footer-top-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  h1.hero-h1 { font-size: 2.1rem; }
  .hero-box { padding: 36px 20px; }
  .device-platforms-grid { grid-template-columns: repeat(2, 1fr); }
  .article-content-box { padding: 28px 18px; }
  .footer-top-grid { grid-template-columns: 1fr; }
  .article-related-grid { grid-template-columns: 1fr; }
}