/* ==========================================================================
   SledCloud (雪橇云 sledcloud.club) - Winter Glacier Design System
   Color Palette: Blue & White (蓝白极光色系, 冰雪浮空质感)
   ========================================================================== */

:root {
  --bg-dark: #070d19;
  --bg-card: rgba(13, 25, 48, 0.7);
  --bg-card-hover: rgba(20, 38, 72, 0.85);
  --border-ice: rgba(165, 216, 255, 0.18);
  --border-ice-glow: rgba(0, 242, 254, 0.4);
  
  --primary-blue: #00f2fe;
  --primary-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --secondary-glow: #38ef7d;
  --accent-cyan: #80d0c7;
  
  --text-main: #ffffff;
  --text-sub: #b0c4de;
  --text-muted: #6b85a3;
  --text-ice-link: #90caf9;
  
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius-lg: 20px;
  --radius-md: 12px;
  --radius-sm: 8px;
  
  --shadow-glow: 0 0 25px rgba(0, 242, 254, 0.25);
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.35);
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-family);
  overflow-x: hidden;
}

body {
  position: relative;
  min-height: 100vh;
  line-height: 1.6;
  background: radial-gradient(circle at 50% 0%, #0e2240 0%, #070d19 70%);
}

/* Canvas background for falling snow */
#snow-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

.site-container {
  position: relative;
  z-index: 2;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Links & Typography */
a {
  color: var(--primary-blue);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  text-shadow: 0 0 10px rgba(0, 242, 254, 0.6);
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.25;
}

/* Glassmorphism Panel */
.glass-panel {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-ice);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  transition: var(--transition);
}

.glass-panel:hover {
  border-color: var(--border-ice-glow);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

/* Header & Navigation */
.navbar {
  position: sticky;
  top: 16px;
  z-index: 100;
  margin-top: 16px;
  padding: 14px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-radius: 50px;
}

.logo-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--primary-gradient);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-glow);
}

.logo-text {
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  background: linear-gradient(180deg, #ffffff 0%, #a5d8ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-badge {
  font-size: 0.75rem;
  background: rgba(0, 242, 254, 0.15);
  color: var(--primary-blue);
  padding: 2px 8px;
  border-radius: 20px;
  border: 1px solid rgba(0, 242, 254, 0.3);
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

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

.nav-links a:hover {
  color: var(--text-main);
}

.btn-cta {
  background: var(--primary-gradient);
  color: #031024 !important;
  font-weight: 700;
  padding: 10px 24px;
  border-radius: 30px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 4px 20px rgba(0, 242, 254, 0.4);
  transition: var(--transition);
}

.btn-cta:hover {
  transform: translateY(-2px) scale(1.03);
  box-shadow: 0 8px 30px rgba(0, 242, 254, 0.6);
  color: #031024 !important;
  text-shadow: none;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-main);
  border: 1px solid var(--border-ice);
  padding: 10px 22px;
  border-radius: 30px;
  font-weight: 600;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.16);
  border-color: var(--primary-blue);
}

/* HERO SECTION */
.hero-section {
  padding: 70px 0 40px;
  text-align: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.3);
  color: var(--primary-blue);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 24px;
  backdrop-filter: blur(8px);
}

.hero-title {
  font-size: 3.5rem;
  line-height: 1.15;
  margin-bottom: 20px;
  background: linear-gradient(180deg, #ffffff 30%, #90caf9 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -1px;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-sub);
  max-width: 760px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 50px;
}

/* REALTIME METRICS DASHBOARD CARD */
.metrics-banner {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  padding: 24px;
  margin-bottom: 60px;
}

.metric-item {
  text-align: center;
  padding: 16px;
  border-right: 1px solid var(--border-ice);
}

.metric-item:last-child {
  border-right: none;
}

.metric-value {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary-blue);
  font-family: monospace;
}

.metric-label {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* BENTO GRID FEATURE HIGHLIGHTS */
.section-title {
  text-align: center;
  margin-bottom: 40px;
}

.section-title h2 {
  font-size: 2.4rem;
  margin-bottom: 12px;
}

.section-title p {
  color: var(--text-sub);
  font-size: 1.05rem;
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 80px;
}

.bento-card {
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
}

.bento-card.span-2 {
  grid-column: span 2;
}

.bento-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(0, 242, 254, 0.12);
  color: var(--primary-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
  border: 1px solid rgba(0, 242, 254, 0.2);
}

.bento-card h3 {
  font-size: 1.35rem;
  margin-bottom: 10px;
}

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

/* LIVE NODE STATUS MONITOR */
.node-monitor {
  padding: 36px;
  margin-bottom: 80px;
}

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

.status-badge-live {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--secondary-glow);
  font-size: 0.9rem;
  font-weight: 600;
}

.pulse-dot {
  width: 10px;
  height: 10px;
  background-color: var(--secondary-glow);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--secondary-glow);
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.node-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.node-card {
  background: rgba(7, 15, 30, 0.6);
  border: 1px solid var(--border-ice);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.flag-icon {
  font-size: 1.4rem;
}

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

.node-type {
  font-size: 0.78rem;
  color: var(--primary-blue);
}

.node-metrics {
  text-align: right;
}

.ping-val {
  color: var(--secondary-glow);
  font-weight: 700;
  font-size: 0.95rem;
  font-family: monospace;
}

.node-load {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* PRICING SECTION */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-bottom: 80px;
}

.price-card {
  padding: 36px 28px;
  text-align: center;
  position: relative;
}

.price-card.popular {
  border-color: var(--primary-blue);
  box-shadow: 0 0 30px rgba(0, 242, 254, 0.3);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary-gradient);
  color: #031024;
  font-weight: 800;
  font-size: 0.78rem;
  padding: 4px 16px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.plan-title {
  font-size: 1.4rem;
  margin-bottom: 8px;
}

.plan-price {
  font-size: 2.8rem;
  font-weight: 800;
  color: #fff;
  margin: 16px 0;
}

.plan-price span {
  font-size: 1rem;
  color: var(--text-muted);
  font-weight: 400;
}

.plan-features {
  list-style: none;
  margin: 24px 0 32px;
  text-align: left;
}

.plan-features li {
  padding: 10px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-sub);
  font-size: 0.92rem;
  display: flex;
  align-items: center;
  gap: 10px;
}

.plan-features li::before {
  content: "✓";
  color: var(--primary-blue);
  font-weight: bold;
}

/* ARTICLES SECTION GRID */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 80px;
}

.article-card {
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.article-tag {
  font-size: 0.78rem;
  color: var(--primary-blue);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 10px;
}

.article-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
  line-height: 1.4;
}

.article-excerpt {
  color: var(--text-sub);
  font-size: 0.88rem;
  margin-bottom: 20px;
}

.article-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* USER REVIEWS & FAQ */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 80px;
}

.review-card {
  padding: 24px;
}

.review-stars {
  color: #ffd166;
  margin-bottom: 12px;
}

.review-text {
  color: var(--text-sub);
  font-size: 0.92rem;
  margin-bottom: 16px;
  font-style: italic;
}

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

.reviewer-tag {
  font-size: 0.78rem;
  color: var(--primary-blue);
}

.faq-container {
  max-width: 860px;
  margin: 0 auto 80px;
}

.faq-item {
  margin-bottom: 16px;
  overflow: hidden;
}

.faq-question {
  padding: 20px 24px;
  font-weight: 600;
  font-size: 1.05rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

.faq-answer {
  padding: 0 24px 20px;
  color: var(--text-sub);
  font-size: 0.95rem;
  display: none;
}

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

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

/* ARTICLE DETAIL PAGES STYLING */
.article-detail-content {
  max-width: 860px;
  margin: 40px auto 80px;
  padding: 40px;
}

.article-header {
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border-ice);
  padding-bottom: 24px;
}

.article-header h1 {
  font-size: 2.2rem;
  margin-bottom: 16px;
  line-height: 1.3;
}

.article-body {
  color: #e2e8f0;
  font-size: 1.05rem;
  line-height: 1.8;
}

.article-body h2 {
  font-size: 1.6rem;
  margin: 36px 0 16px;
  color: var(--primary-blue);
}

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

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

.article-body ul, .article-body ol {
  margin: 0 0 24px 24px;
  color: var(--text-sub);
}

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

.article-cta-box {
  margin: 40px 0;
  padding: 30px;
  text-align: center;
  background: linear-gradient(135deg, rgba(0, 242, 254, 0.1) 0%, rgba(79, 172, 254, 0.1) 100%);
  border: 1px solid var(--primary-blue);
  border-radius: var(--radius-md);
}

.related-articles {
  margin-top: 60px;
  padding-top: 40px;
  border-top: 1px solid var(--border-ice);
}

/* FOOTER & PBN FRIENDSHIP LINKS (REQUIREMENT MANDATE) */
footer {
  position: relative;
  z-index: 2;
  background: rgba(4, 9, 20, 0.95);
  border-top: 1px solid var(--border-ice);
  padding: 50px 0 30px;
  color: var(--text-muted);
  font-size: 0.88rem;
  text-align: center;
}

.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

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

.footer-nav a {
  color: var(--text-sub);
}

.footer-nav a:hover {
  color: var(--primary-blue);
}

/* SPECIFIC REQUIREMENT: Low-key, aesthetic, small font friendship links block in footer */
.friendship-links-section {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px dashed rgba(165, 216, 255, 0.12);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.friendship-title {
  font-size: 0.78rem;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.friendship-links-list {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 20px;
  list-style: none;
}

.friendship-links-list li a {
  font-size: 0.82rem;
  color: var(--text-ice-link);
  text-decoration: none;
  opacity: 0.85;
  transition: var(--transition);
}

.friendship-links-list li a:hover {
  opacity: 1;
  color: var(--primary-blue);
  text-shadow: 0 0 8px rgba(0, 242, 254, 0.4);
}

.copyright-text {
  margin-top: 20px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Responsive Rules */
@media (max-width: 992px) {
  .bento-grid, .pricing-grid, .articles-grid, .reviews-grid {
    grid-template-columns: 1fr;
  }
  .bento-card.span-2 {
    grid-column: span 1;
  }
  .metrics-banner {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-title {
    font-size: 2.4rem;
  }
  .navbar {
    flex-wrap: wrap;
    gap: 16px;
  }
  .nav-links {
    display: none;
  }
}