/* ==========================================================================
   一翻云 (Yifan Cloud Airport) - Design System & Stylesheet
   Style: 极简一键直连风 (One-Click Minimalist Apple SaaS)
   ========================================================================== */

:root {
  /* Color Palette */
  --bg-main: #FAFAFC;
  --bg-card: #FFFFFF;
  --bg-card-hover: #F8FAFC;
  --text-primary: #0F172A;
  --text-secondary: #64748B;
  --text-muted: #94A3B8;
  --border-color: #E2E8F0;
  --border-light: #F1F5F9;
  
  /* Brand Accent Colors */
  --accent-blue: #0284C7;
  --accent-blue-hover: #0369A1;
  --accent-blue-light: #E0F2FE;
  --accent-orange: #F97316;
  --accent-orange-light: #FFEDD5;
  --accent-green: #10B981;
  --accent-green-light: #D1FAE5;
  --accent-star: #F59E0B;
  
  /* Effects */
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.03);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.06);
  --shadow-blue: 0 10px 25px rgba(2, 132, 199, 0.2);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  
  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Reset & Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

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

/* Background Dynamic Canvas Container */
#bgCanvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  opacity: 0.6;
}

/* Layout Elements */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
}

h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  text-align: center;
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 680px;
  margin: 0 auto 48px auto;
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: var(--transition);
}

/* Badges & Tags */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  width: fit-content;
}

.badge-blue {
  background-color: var(--accent-blue-light);
  color: var(--accent-blue);
}

.badge-orange {
  background-color: var(--accent-orange-light);
  color: var(--accent-orange);
}

.badge-green {
  background-color: var(--accent-green-light);
  color: var(--accent-green);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary {
  background-color: var(--accent-blue);
  color: #FFFFFF;
  box-shadow: var(--shadow-blue);
}

.btn-primary:hover {
  background-color: var(--accent-blue-hover);
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(2, 132, 199, 0.3);
}

.btn-secondary {
  background-color: #FFFFFF;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background-color: var(--bg-card-hover);
  border-color: var(--text-muted);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 18px 36px;
  font-size: 1.125rem;
  border-radius: var(--radius-md);
}

/* Header & Navbar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 252, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
  transition: var(--transition);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--accent-blue), #38BDF8);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.25);
}

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

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--accent-blue);
}

/* Hero Section */
.hero {
  padding: 70px 0 50px 0;
  text-align: center;
}

.hero-tag {
  margin: 0 auto 20px auto;
}

.hero-title {
  margin-bottom: 20px;
}

.hero-title span {
  color: var(--accent-blue);
  position: relative;
  display: inline-block;
}

.hero-description {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 36px auto;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 50px;
  flex-wrap: wrap;
}

/* 3-Step Visual Workflow Banner */
.workflow-banner {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  box-shadow: var(--shadow-md);
  margin-top: 40px;
}

.workflow-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  position: relative;
}

.workflow-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 20px;
  background: var(--bg-main);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.workflow-step:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue-light);
  box-shadow: var(--shadow-sm);
}

.step-num {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: var(--accent-blue-light);
  color: var(--accent-blue);
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
}

.step-title {
  font-weight: 700;
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.step-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Section Spacing */
.section {
  padding: 80px 0;
}

/* Waterfall Masonry Layout Section */
.masonry-grid {
  column-count: 3;
  column-gap: 24px;
}

.masonry-card {
  break-inside: avoid;
  margin-bottom: 24px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.masonry-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: #CBD5E1;
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: var(--accent-blue-light);
  color: var(--accent-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.card-icon svg {
  width: 26px;
  height: 26px;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.card-text {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.card-img-wrapper {
  margin: -32px -28px 24px -28px;
  background: #F1F5F9;
  overflow: hidden;
}

.card-img-wrapper svg,
.card-img-wrapper img {
  width: 100%;
  height: auto;
  display: block;
}

/* Node Latency Monitor Section */
.monitor-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-md);
}

.monitor-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
}

.node-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.node-item {
  background: var(--bg-main);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: var(--transition);
}

.node-item:hover {
  border-color: var(--accent-blue-light);
  background: #FFFFFF;
}

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

.flag {
  font-size: 1.4rem;
}

.node-name {
  font-weight: 600;
  font-size: 0.95rem;
}

.node-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.node-ping {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 0.9rem;
}

.ping-dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--accent-green);
  box-shadow: 0 0 8px rgba(16, 185, 129, 0.6);
}

.ping-green { color: var(--accent-green); }
.ping-blue { color: var(--accent-blue); }

/* Pricing Section */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.pricing-card.popular {
  border: 2px solid var(--accent-blue);
  box-shadow: 0 16px 40px rgba(2, 132, 199, 0.12);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-blue);
  color: white;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.plan-price {
  font-size: 2.75rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 24px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.plan-price span {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
}

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

.plan-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.plan-features svg {
  width: 18px;
  height: 18px;
  color: var(--accent-blue);
  flex-shrink: 0;
}

/* Section 6: User Reviews / Testimonials Section */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

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

.testimonial-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-md);
}

.stars {
  display: flex;
  gap: 4px;
  color: var(--accent-star);
  margin-bottom: 14px;
}

.testimonial-quote {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

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

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--accent-blue), #38BDF8);
  color: white;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

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

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

/* FAQ Accordion Section */
.faq-grid {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-header {
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.05rem;
}

.faq-toggle {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-full);
  background: var(--bg-main);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.faq-content {
  padding: 0 24px 20px 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  display: none;
}

.faq-item.active .faq-toggle {
  transform: rotate(180deg);
  background: var(--accent-blue-light);
  color: var(--accent-blue);
}

.faq-item.active .faq-content {
  display: block;
}

/* SEO Articles Grid Section */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}

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

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

.article-tag {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-blue);
  margin-bottom: 8px;
}

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

.article-excerpt {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

.article-link {
  font-size: 0.9rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent-blue);
}

/* Article Detail Page Layout */
.article-detail-container {
  max-width: 840px;
  margin: 40px auto 80px auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
  box-shadow: var(--shadow-md);
}

.article-header {
  margin-bottom: 36px;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 24px;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-body h2 {
  text-align: left;
  font-size: 1.6rem;
  margin: 36px 0 16px 0;
}

.article-body h3 {
  font-size: 1.25rem;
  margin: 28px 0 12px 0;
}

.article-body p {
  margin-bottom: 20px;
  color: #334155;
}

.article-body ul, .article-body ol {
  margin: 0 0 24px 24px;
  color: #334155;
}

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

/* Footer (No Sitemap/Robots links displayed in UI) */
footer {
  background: #FFFFFF;
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px 0;
  margin-top: 80px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 48px;
}

.footer-col p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 12px;
  max-width: 300px;
}

.footer-heading {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
}

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

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.footer-bottom {
  border-top: 1px solid var(--border-light);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-muted);
  font-size: 0.85rem;
  flex-wrap: wrap;
  gap: 12px;
}

/* Responsive Media Queries */
@media (max-width: 992px) {
  .masonry-grid {
    column-count: 2;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
  }
  .workflow-steps {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .masonry-grid {
    column-count: 1;
  }
  .nav-links {
    display: none;
  }
  .article-detail-container {
    padding: 24px;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
}