/* ==========================================================================
   ByWave 机场 - 深海声呐 (Deep Sea Sonar) 核心视觉样式表
   艺术方向：冷静、精准、高端。
   配色：背景 #04101C | 面板 #0A1B2A | 主强调色 #35E0FF (电光青) | CTA #FF6B4A (信标珊瑚) | 正文 #A8C3D1
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600;700&family=Space+Grotesk:wght@400;500;600;700&display=swap');

:root {
  --bg-color: #04101C;
  --panel-color: #0A1B2A;
  --panel-hover: #0E2438;
  --panel-active: #132D45;
  --cyan: #35E0FF;
  --cyan-10: rgba(53, 224, 255, 0.10);
  --cyan-14: rgba(53, 224, 255, 0.14);
  --cyan-25: rgba(53, 224, 255, 0.25);
  --cyan-50: rgba(53, 224, 255, 0.50);
  --coral: #FF6B4A;
  --coral-hover: #ff8264;
  --coral-glow: rgba(255, 107, 74, 0.28);
  --text-main: #A8C3D1;
  --text-bright: #FFFFFF;
  --text-muted: #5B788A;
  --border-line: rgba(53, 224, 255, 0.14);
  --border-highlight: rgba(53, 224, 255, 0.4);
  
  --font-heading: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'IBM Plex Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

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

html {
  scroll-behavior: smooth;
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: var(--font-heading);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background-color: var(--bg-color);
  background-image: 
    linear-gradient(to right, rgba(53, 224, 255, 0.03) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(53, 224, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
}

/* 链接全局 */
a {
  color: var(--cyan);
  text-decoration: none;
  transition: all 0.2s ease;
}

a:hover {
  color: var(--text-bright);
}

/* 容器规范 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 微标签与等宽字体规则 */
.mono-tag {
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  font-size: 0.75rem;
  color: var(--cyan);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.mono-tag::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  background-color: var(--cyan);
  box-shadow: 0 0 8px var(--cyan);
  border-radius: 50%;
}

.sonar-ping-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--coral);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  background: rgba(255, 107, 74, 0.08);
  border: 1px solid rgba(255, 107, 74, 0.3);
  border-radius: 2px;
}

.sonar-ping-badge span.pulse-dot {
  width: 7px;
  height: 7px;
  background-color: var(--coral);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--coral);
  animation: pulse-ring 2s infinite ease-in-out;
}

@keyframes pulse-ring {
  0% { transform: scale(0.9); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; box-shadow: 0 0 12px var(--coral); }
  100% { transform: scale(0.9); opacity: 0.8; }
}

/* ==========================================================================
   Header & 导航
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(4, 16, 28, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-line);
  height: 72px;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text-bright);
}

.brand-logo-text span {
  color: var(--cyan);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-link {
  font-family: var(--font-heading);
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-main);
  transition: color 0.2s ease;
}

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

.nav-link.highlight {
  color: var(--cyan);
  font-weight: 600;
  position: relative;
}

.nav-link.highlight::after {
  content: 'NEW';
  font-family: var(--font-mono);
  font-size: 0.65rem;
  background: var(--cyan-14);
  color: var(--cyan);
  padding: 1px 4px;
  border-radius: 2px;
  margin-left: 5px;
  border: 1px solid var(--border-line);
}

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

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: 2px;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  text-decoration: none;
  white-space: nowrap;
}

/* CTA 珊瑚色按钮 */
.btn-coral {
  background-color: var(--coral);
  color: #FFFFFF;
  border: 1px solid var(--coral);
  box-shadow: 0 0 16px var(--coral-glow);
}

.btn-coral:hover {
  background-color: var(--coral-hover);
  color: #FFFFFF;
  box-shadow: 0 0 24px rgba(255, 107, 74, 0.5);
  transform: translateY(-2px);
}

/* 次级青线按钮 */
.btn-outline-cyan {
  background: transparent;
  color: var(--cyan);
  border: 1px solid var(--cyan-50);
}

.btn-outline-cyan:hover {
  background: var(--cyan-10);
  color: var(--text-bright);
  border-color: var(--cyan);
  box-shadow: 0 0 16px var(--cyan-25);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.85rem;
}

/* ==========================================================================
   Hero 主视觉区 (深海声呐雷达与实时波形)
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 90px 0 70px;
  overflow: hidden;
  border-bottom: 1px solid var(--border-line);
}

/* 声呐同心圆底纹 */
.sonar-background {
  position: absolute;
  top: 50%;
  right: -80px;
  transform: translateY(-50%);
  width: 600px;
  height: 600px;
  pointer-events: none;
  z-index: 0;
  opacity: 0.6;
}

.sonar-ring {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  border: 1px solid var(--border-line);
}

.sonar-ring-1 { width: 140px; height: 140px; }
.sonar-ring-2 { width: 280px; height: 280px; }
.sonar-ring-3 { width: 440px; height: 440px; }
.sonar-ring-4 { width: 580px; height: 580px; }

/* 雷达扫掠线 */
.radar-sweep {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 290px;
  height: 290px;
  transform-origin: top left;
  background: conic-gradient(from 0deg, rgba(53, 224, 255, 0.18) 0deg, rgba(53, 224, 255, 0.05) 45deg, transparent 90deg);
  border-radius: 100% 0 0 0;
  animation: radar-spin 8s linear infinite;
}

@keyframes radar-spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

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

.hero-meta-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.25rem;
  line-height: 1.15;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.hero-title .brand-accent {
  color: var(--cyan);
}

.hero-title .deep-signal {
  display: block;
  font-size: 2.1rem;
  color: var(--text-main);
  font-weight: 400;
  margin-top: 8px;
}

.hero-desc {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--text-main);
  margin-bottom: 36px;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 36px;
}

/* 实时指标读数面板 (Telemetry) */
.telemetry-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  padding: 16px 20px;
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  border-radius: 2px;
}

.telemetry-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.telemetry-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.telemetry-val {
  font-family: var(--font-mono);
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--cyan);
}

.telemetry-val.highlight {
  color: var(--coral);
}

/* 实时波形视窗 */
.hero-visual-card {
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  padding: 24px;
  position: relative;
  border-radius: 2px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
}

.terminal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-line);
  margin-bottom: 18px;
}

.terminal-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.15em;
  color: var(--cyan);
}

.terminal-status {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #38ef7d;
}

.terminal-status .dot {
  width: 6px;
  height: 6px;
  background: #38ef7d;
  border-radius: 50%;
  box-shadow: 0 0 6px #38ef7d;
}

/* 纯 SVG/CSS 动态波形 */
.wave-canvas-wrap {
  width: 100%;
  height: 160px;
  position: relative;
  overflow: hidden;
  background: rgba(4, 16, 28, 0.6);
  border: 1px solid rgba(53, 224, 255, 0.08);
}

.wave-svg {
  width: 200%;
  height: 100%;
  animation: wave-pan 6s linear infinite;
}

@keyframes wave-pan {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

.visual-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 18px;
}

.stat-box {
  background: rgba(4, 16, 28, 0.5);
  border: 1px solid var(--border-line);
  padding: 12px;
}

.stat-box .s-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.stat-box .s-value {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-top: 4px;
}

/* ==========================================================================
   通用区块设计
   ========================================================================== */
.section-padding {
  padding: 90px 0;
  border-bottom: 1px solid var(--border-line);
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--text-bright);
  margin: 12px 0 16px;
  letter-spacing: -0.01em;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-main);
  line-height: 1.7;
}

/* ==========================================================================
   产品核心优势 (3个图文卡片)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  padding: 36px 28px;
  border-radius: 2px;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-highlight);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.5);
}

.feature-icon-box {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--cyan-25);
  background: rgba(53, 224, 255, 0.05);
  color: var(--cyan);
  margin-bottom: 24px;
}

.feature-card h3 {
  font-size: 1.35rem;
  color: var(--text-bright);
  margin-bottom: 14px;
  font-weight: 600;
}

.feature-card p {
  color: var(--text-main);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 20px;
  flex-grow: 1;
}

.feature-spec-list {
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-line);
  padding-top: 16px;
}

.feature-spec-list li {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
}

.feature-spec-list li span:last-child {
  color: var(--cyan);
}

/* ==========================================================================
   流媒体与 AI 支持图卡
   ========================================================================== */
.ecosystem-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.ecosystem-card {
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  padding: 36px;
  border-radius: 2px;
}

.ecosystem-card h3 {
  font-size: 1.4rem;
  color: var(--text-bright);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.ecosystem-card p {
  color: var(--text-main);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 24px;
}

.badge-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.media-pill {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  padding: 8px 14px;
  background: rgba(4, 16, 28, 0.7);
  border: 1px solid var(--border-line);
  color: var(--text-bright);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: 2px;
  transition: border-color 0.2s;
}

.media-pill:hover {
  border-color: var(--cyan);
}

.media-pill svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.media-pill.stream-netflix { color: #E50914; border-color: rgba(229, 9, 20, 0.3); }
.media-pill.stream-disney { color: #113CCF; border-color: rgba(53, 224, 255, 0.3); }
.media-pill.stream-yt { color: #FF0000; border-color: rgba(255, 0, 0, 0.3); }
.media-pill.ai-openai { color: #10A37F; border-color: rgba(16, 163, 127, 0.3); }
.media-pill.ai-claude { color: #D97706; border-color: rgba(217, 119, 6, 0.3); }
.media-pill.ai-midjourney { color: #35E0FF; border-color: var(--cyan-25); }

/* ==========================================================================
   套餐价格对比表 (参考网上真实高规格专线机场定价)
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.pricing-card {
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  border-radius: 2px;
  transition: all 0.3s ease;
}

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

.pricing-card.popular {
  border-color: var(--cyan);
  box-shadow: 0 0 24px var(--cyan-14);
}

.popular-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--cyan);
  color: #04101C;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 3px 12px;
  border-radius: 2px;
  text-transform: uppercase;
}

.plan-header {
  border-bottom: 1px solid var(--border-line);
  padding-bottom: 20px;
  margin-bottom: 24px;
}

.plan-tier {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.15em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.plan-name {
  font-size: 1.4rem;
  color: var(--text-bright);
  font-weight: 700;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  margin-top: 16px;
}

.plan-currency {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--text-main);
  margin-right: 2px;
}

.plan-amount {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-bright);
  line-height: 1;
}

.plan-period {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-left: 6px;
}

.plan-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.plan-features li {
  font-size: 0.9rem;
  color: var(--text-main);
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid rgba(53, 224, 255, 0.05);
}

.plan-features li svg {
  width: 14px;
  height: 14px;
  color: var(--cyan);
  flex-shrink: 0;
}

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

.testimonial-card {
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  padding: 32px 26px;
  position: relative;
  display: flex;
  flex-direction: column;
}

.testimonial-rating {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
  color: #ffb800;
}

.testimonial-quote {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text-main);
  margin-bottom: 24px;
  flex-grow: 1;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 14px;
  border-top: 1px solid var(--border-line);
  padding-top: 16px;
}

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--panel-hover);
  border: 1px solid var(--border-line);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--cyan);
  font-size: 0.95rem;
}

.author-meta .name {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-bright);
}

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

/* ==========================================================================
   常见问题解答 (FAQ)
   ========================================================================== */
.faq-wrap {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  border-radius: 2px;
  overflow: hidden;
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-bright);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-icon-cross {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--cyan);
  transition: transform 0.25s ease;
}

.faq-item[open] .faq-icon-cross {
  transform: rotate(45deg);
  color: var(--coral);
}

.faq-content {
  padding: 0 24px 22px;
  color: var(--text-main);
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px dashed rgba(53, 224, 255, 0.08);
  padding-top: 16px;
}

/* ==========================================================================
   CTA 横幅区
   ========================================================================== */
.bottom-cta-box {
  background: linear-gradient(180deg, var(--panel-color) 0%, rgba(4, 16, 28, 0.95) 100%);
  border: 1px solid var(--cyan-25);
  padding: 64px 32px;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.6);
}

.bottom-cta-box h2 {
  font-size: 2.4rem;
  color: var(--text-bright);
  margin-bottom: 16px;
}

.bottom-cta-box p {
  color: var(--text-main);
  max-width: 600px;
  margin: 0 auto 32px;
  font-size: 1.05rem;
}

/* ==========================================================================
   页脚规范
   需求要求：页脚只保留这四个标题，内容打开新的页面展示：
   - 网站地图
   - 关于我们
   - 服务条款
   - 隐私政策
   ========================================================================== */
.site-footer {
  background: #020910;
  border-top: 1px solid var(--border-line);
  padding: 48px 0;
}

.footer-nav-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 40px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.footer-nav-link {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  padding: 6px 12px;
  transition: all 0.2s ease;
  position: relative;
}

.footer-nav-link:hover {
  color: var(--cyan);
}

.footer-copy {
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

/* ==========================================================================
   子页面统一布局 (文章页、关于我们、条款等)
   ========================================================================== */
.article-header {
  padding: 60px 0 36px;
  border-bottom: 1px solid var(--border-line);
  background: rgba(10, 27, 42, 0.4);
}

.article-body {
  max-width: 820px;
  margin: 0 auto;
  padding: 50px 24px 80px;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-main);
}

.article-body h2 {
  font-size: 1.7rem;
  color: var(--text-bright);
  margin: 40px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-line);
}

.article-body h3 {
  font-size: 1.3rem;
  color: var(--cyan);
  margin: 28px 0 12px;
}

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

.article-body ul, .article-body ol {
  margin: 0 0 24px 24px;
}

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

.article-body blockquote {
  background: var(--panel-color);
  border-left: 3px solid var(--cyan);
  padding: 16px 20px;
  margin: 24px 0;
  color: #c0d8e6;
  font-style: italic;
}

.dofollow-anchor {
  color: var(--cyan);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.dofollow-anchor:hover {
  color: var(--text-bright);
}

/* 文章列表网格 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-top: 36px;
}

.article-card {
  background: var(--panel-color);
  border: 1px solid var(--border-line);
  padding: 28px;
  border-radius: 2px;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-highlight);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.4);
}

.article-card-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.article-card-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-bright);
  line-height: 1.4;
  margin-bottom: 14px;
}

.article-card-title a {
  color: var(--text-bright);
}

.article-card-title a:hover {
  color: var(--cyan);
}

.article-card-excerpt {
  color: var(--text-main);
  font-size: 0.92rem;
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

/* ==========================================================================
   响应式适配 (@media 移动端优化)
   ========================================================================== */
@media (max-width: 1024px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-title {
    font-size: 2.8rem;
  }
}

@media (max-width: 840px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .features-grid,
  .testimonials-grid,
  .articles-grid,
  .ecosystem-grid {
    grid-template-columns: 1fr;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  .sonar-background {
    display: none;
  }
}

@media (max-width: 640px) {
  .site-header {
    height: auto;
    padding: 14px 0;
  }
  .header-inner {
    flex-direction: column;
    gap: 14px;
  }
  .nav-menu {
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
  }
  .hero-title {
    font-size: 2.1rem;
  }
  .hero-title .deep-signal {
    font-size: 1.4rem;
  }
  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }
  .hero-buttons .btn {
    width: 100%;
    padding: 14px 20px;
  }
  .telemetry-strip {
    flex-direction: column;
    gap: 12px;
  }
  .footer-nav-bar {
    flex-direction: column;
    gap: 16px;
  }
  .section-padding {
    padding: 60px 0;
  }
}