/* ==========================================================================
   吹雪云官网 - ChuiXue Cloud (chuixuecloud.homes)
   Theme: Icy Frost / Snow Pure Light Aesthetic (浅色冰雪清爽风)
   ========================================================================== */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

  /* Colors */
  --bg-main: #f8fafc;
  --bg-gradient: linear-gradient(180deg, #f0f7ff 0%, #f8fafc 40%, #ffffff 100%);
  --bg-card: rgba(255, 255, 255, 0.82);
  --bg-card-hover: rgba(255, 255, 255, 0.95);
  --card-border: rgba(226, 232, 240, 0.85);
  --card-border-glow: rgba(56, 189, 248, 0.4);

  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --text-light: #94a3b8;

  --frost-blue: #0284c7;
  --frost-light: #38bdf8;
  --frost-ice: #e0f2fe;
  --frost-cyan: #06b6d4;
  --frost-gradient: linear-gradient(135deg, #0284c7 0%, #06b6d4 50%, #38bdf8 100%);
  --frost-glow: 0 8px 30px rgba(14, 165, 233, 0.25);

  --accent-green: #10b981;
  --accent-amber: #f59e0b;
  --accent-red: #ef4444;
  --accent-purple: #8b5cf6;

  --shadow-sm: 0 2px 8px rgba(148, 163, 184, 0.1);
  --shadow-md: 0 8px 24px rgba(148, 163, 184, 0.14);
  --shadow-lg: 0 16px 40px rgba(148, 163, 184, 0.2);
  --shadow-frost: 0 12px 32px rgba(56, 189, 248, 0.18);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-full: 9999px;

  --container-width: 1240px;
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  scroll-behavior: smooth;
  color: var(--text-primary);
  background: var(--bg-main);
  -webkit-text-size-adjust: 100%;
}

body {
  position: relative;
  overflow-x: hidden;
  line-height: 1.65;
  background: var(--bg-gradient);
  min-height: 100vh;
}

/* Background Canvas & Snow Ambient */
#snow-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 1;
  opacity: 0.75;
}

.ambient-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.55;
}

.ambient-glow-1 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(186, 230, 253, 0.6) 0%, rgba(224, 242, 254, 0) 70%);
  top: -150px;
  right: -100px;
}

.ambient-glow-2 {
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(207, 250, 254, 0.5) 0%, rgba(240, 249, 255, 0) 70%);
  top: 40%;
  left: -200px;
}

/* Layout Container */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

/* Typography */
h1, h2, h3, h4, h5 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -0.02em;
}

p {
  color: var(--text-secondary);
}

a {
  color: var(--frost-blue);
  text-decoration: none;
  transition: all 0.25s ease;
}

a:hover {
  color: var(--frost-light);
}

/* Common Section Headers */
.section {
  padding: 100px 0;
  position: relative;
  z-index: 2;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 60px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--frost-blue);
  background: var(--frost-ice);
  border: 1px solid rgba(56, 189, 248, 0.3);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
  box-shadow: 0 2px 10px rgba(56, 189, 248, 0.12);
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #0f172a 30%, #0369a1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

/* Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  text-align: center;
  text-decoration: none;
}

.btn-primary {
  background: var(--frost-gradient);
  color: #ffffff !important;
  box-shadow: var(--shadow-frost);
  border: 1px solid rgba(255, 255, 255, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 36px rgba(14, 165, 233, 0.35);
  filter: brightness(1.05);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.8);
  color: var(--text-primary);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(10px);
}

.btn-outline:hover {
  background: #ffffff;
  border-color: var(--frost-light);
  color: var(--frost-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
  border-radius: var(--radius-md);
}

.btn-pulse {
  position: relative;
}

.btn-pulse::after {
  content: "";
  position: absolute;
  top: -4px;
  left: -4px;
  right: -4px;
  bottom: -4px;
  border-radius: inherit;
  border: 2px solid rgba(56, 189, 248, 0.6);
  animation: pulse-ring 2.2s cubic-bezier(0.24, 0, 0.38, 1) infinite;
  pointer-events: none;
}

@keyframes pulse-ring {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.05); opacity: 0; }
  100% { transform: scale(1.05); opacity: 0; }
}

/* Header & Navbar */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  transition: all 0.3s ease;
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 74px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand-icon {
  width: 38px;
  height: 38px;
  background: var(--frost-gradient);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1.3rem;
  box-shadow: 0 4px 14px rgba(14, 165, 233, 0.3);
}

.brand-name {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.brand-badge {
  font-size: 0.65rem;
  font-weight: 700;
  background: linear-gradient(135deg, #0ea5e9, #38bdf8);
  color: #fff;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

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

.nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-secondary);
  position: relative;
  padding: 6px 2px;
}

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--frost-gradient);
  transition: all 0.25s ease;
  transform: translateX(-50%);
  border-radius: 2px;
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

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

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-primary);
  cursor: pointer;
  padding: 6px;
}

/* Hero Section */
.hero-section {
  padding: 80px 0 90px;
  position: relative;
  text-align: center;
}

.hero-content {
  max-width: 900px;
  margin: 0 auto;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 255, 255, 0.9);
  padding: 8px 18px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(186, 230, 253, 0.9);
  box-shadow: 0 4px 18px rgba(14, 165, 233, 0.12);
  margin-bottom: 24px;
}

.hero-pill-badge {
  background: var(--frost-gradient);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-full);
}

.hero-pill-text {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.hero-title {
  font-size: 3.4rem;
  line-height: 1.2;
  margin-bottom: 22px;
  font-weight: 900;
  letter-spacing: -0.03em;
}

.text-gradient {
  background: var(--frost-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.22rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 38px;
  max-width: 780px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  max-width: 1040px;
  margin: 0 auto;
  padding-top: 24px;
}

.metric-card {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
  text-align: center;
}

.metric-card:hover {
  transform: translateY(-3px);
  border-color: var(--card-border-glow);
  box-shadow: var(--shadow-md);
}

.metric-value {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--frost-blue);
  line-height: 1.1;
  margin-bottom: 6px;
}

.metric-label {
  font-size: 0.88rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Core Advantages Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 34px 28px;
  box-shadow: var(--shadow-sm);
  transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--frost-gradient);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--card-border-glow);
  box-shadow: var(--shadow-frost);
  background: var(--bg-card-hover);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon-wrapper {
  width: 58px;
  height: 58px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(224, 242, 254, 0.8), rgba(186, 230, 253, 0.4));
  border: 1px solid rgba(56, 189, 248, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.7rem;
  margin-bottom: 20px;
  color: var(--frost-blue);
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* Node Latency & Status Dashboard */
.status-dashboard {
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: 32px;
}

.dashboard-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--card-border);
  margin-bottom: 24px;
}

.dashboard-status-indicator {
  display: flex;
  align-items: center;
  gap: 12px;
}

.status-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-green);
  position: relative;
}

.status-dot::after {
  content: "";
  position: absolute;
  top: -3px;
  left: -3px;
  right: -3px;
  bottom: -3px;
  border-radius: 50%;
  border: 2px solid var(--accent-green);
  animation: pulse-ring 2s infinite;
}

.dashboard-tabs {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(241, 245, 249, 0.9);
  padding: 4px;
  border-radius: var(--radius-md);
}

.tab-btn {
  background: none;
  border: none;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.tab-btn.active, .tab-btn:hover {
  background: #ffffff;
  color: var(--frost-blue);
  box-shadow: var(--shadow-sm);
}

.nodes-table-wrapper {
  overflow-x: auto;
}

.nodes-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.nodes-table th {
  padding: 14px 18px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  border-bottom: 1px solid var(--card-border);
}

.nodes-table td {
  padding: 16px 18px;
  font-size: 0.92rem;
  border-bottom: 1px solid rgba(226, 232, 240, 0.6);
  vertical-align: middle;
}

.nodes-table tr:last-child td {
  border-bottom: none;
}

.nodes-table tr:hover td {
  background: rgba(240, 249, 255, 0.5);
}

.node-name-cell {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 600;
}

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

.badge-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 4px;
  background: var(--frost-ice);
  color: var(--frost-blue);
  border: 1px solid rgba(56, 189, 248, 0.25);
}

.badge-green {
  background: rgba(209, 250, 229, 0.8);
  color: #065f46;
  border-color: rgba(16, 185, 129, 0.3);
}

.latency-cell {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent-green);
}

.load-bar-wrap {
  width: 110px;
  height: 6px;
  background: #e2e8f0;
  border-radius: var(--radius-full);
  overflow: hidden;
}

.load-bar {
  height: 100%;
  background: linear-gradient(90deg, #10b981, #0284c7);
  border-radius: var(--radius-full);
}

/* Pricing Plans Section */
.pricing-switcher {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-bottom: 48px;
}

.switch-pill {
  display: inline-flex;
  background: rgba(226, 232, 240, 0.7);
  padding: 4px;
  border-radius: var(--radius-full);
}

.cycle-btn {
  background: none;
  border: none;
  padding: 9px 22px;
  border-radius: var(--radius-full);
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
}

.cycle-btn.active {
  background: #ffffff;
  color: var(--frost-blue);
  box-shadow: var(--shadow-sm);
}

.discount-tag {
  background: #fee2e2;
  color: #b91c1c;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: var(--radius-full);
  margin-left: 4px;
}

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

.pricing-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 34px 26px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.pricing-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-frost);
  border-color: var(--card-border-glow);
}

.pricing-card.popular {
  border: 2px solid var(--frost-light);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.95) 0%, rgba(240, 249, 255, 0.9) 100%);
  box-shadow: var(--shadow-frost);
  transform: scale(1.03);
}

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

.popular-badge {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--frost-gradient);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 12px rgba(14, 165, 233, 0.35);
  letter-spacing: 0.04em;
  white-space: nowrap;
}

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

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  min-height: 42px;
  margin-bottom: 20px;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--card-border);
}

.price-currency {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
}

.price-amount {
  font-size: 2.7rem;
  font-weight: 900;
  color: var(--text-primary);
  line-height: 1;
}

.price-cycle {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.plan-features {
  list-style: none;
  margin-bottom: 30px;
  flex-grow: 1;
}

.plan-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.9rem;
  margin-bottom: 12px;
  color: var(--text-secondary);
}

.feature-check {
  color: var(--accent-green);
  font-size: 1rem;
  line-height: 1.4;
}

/* User Reviews Section */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

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

.review-stars {
  color: #fbbf24;
  font-size: 1.05rem;
  margin-bottom: 14px;
  letter-spacing: 2px;
}

.review-text {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
  font-style: italic;
}

.reviewer-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px solid rgba(226, 232, 240, 0.6);
}

.reviewer-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #e0f2fe, #bae6fd);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

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

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

/* FAQ Accordion Section */
.faq-container {
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  overflow: hidden;
  transition: all 0.25s ease;
}

.faq-item:hover {
  border-color: var(--card-border-glow);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.faq-chevron {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  color: var(--frost-blue);
}

.faq-item.open .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
  padding: 0 24px;
  color: var(--text-secondary);
  font-size: 0.96rem;
  line-height: 1.7;
}

.faq-item.open .faq-answer {
  max-height: 800px;
  padding: 0 24px 22px;
  transition: max-height 0.35s cubic-bezier(1, 0, 1, 0);
}

/* Knowledge Base & Tutorials Section */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.article-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
  text-decoration: none;
}

.article-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-frost);
  border-color: var(--card-border-glow);
}

.article-cover {
  height: 180px;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.2rem;
  color: #fff;
}

.cover-1 { background: linear-gradient(135deg, #0284c7, #38bdf8); }
.cover-2 { background: linear-gradient(135deg, #059669, #34d399); }
.cover-3 { background: linear-gradient(135deg, #7c3aed, #a78bfa); }
.cover-4 { background: linear-gradient(135deg, #ea580c, #fb923c); }
.cover-5 { background: linear-gradient(135deg, #2563eb, #60a5fa); }
.cover-6 { background: linear-gradient(135deg, #db2777, #f472b6); }
.cover-7 { background: linear-gradient(135deg, #0d9488, #2dd4bf); }
.cover-8 { background: linear-gradient(135deg, #e11d48, #fb7185); }
.cover-9 { background: linear-gradient(135deg, #4f46e5, #818cf8); }
.cover-10 { background: linear-gradient(135deg, #d97706, #fbbf24); }
.cover-11 { background: linear-gradient(135deg, #475569, #94a3b8); }
.cover-12 { background: linear-gradient(135deg, #0891b2, #67e8f9); }

.article-category {
  position: absolute;
  top: 14px;
  left: 14px;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(8px);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-full);
}

.article-content {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.article-title {
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.45;
  margin-bottom: 12px;
  transition: color 0.2s ease;
}

.article-card:hover .article-title {
  color: var(--frost-blue);
}

.article-summary {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  padding-top: 14px;
  border-top: 1px solid rgba(226, 232, 240, 0.6);
}

/* Call to Action Banner */
.cta-banner {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.95), rgba(6, 182, 212, 0.92));
  border-radius: var(--radius-lg);
  padding: 60px 48px;
  color: #fff;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 45px rgba(2, 132, 199, 0.35);
  margin: 60px 0 100px;
}

.cta-banner::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.2) 0%, transparent 60%);
  pointer-events: none;
}

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

.cta-banner p {
  color: rgba(255, 255, 255, 0.92);
  font-size: 1.15rem;
  max-width: 680px;
  margin: 0 auto 32px;
}

.btn-white {
  background: #ffffff;
  color: var(--frost-blue) !important;
  font-weight: 700;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.btn-white:hover {
  background: #f8fafc;
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.2);
}

/* Footer */
.site-footer {
  background: #ffffff;
  border-top: 1px solid var(--card-border);
  padding: 80px 0 40px;
  position: relative;
  z-index: 2;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 50px;
}

.footer-brand p {
  margin-top: 14px;
  color: var(--text-muted);
  font-size: 0.92rem;
  max-width: 320px;
  line-height: 1.65;
}

.footer-col h4 {
  font-size: 1rem;
  margin-bottom: 18px;
  color: var(--text-primary);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

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

.footer-links a:hover {
  color: var(--frost-blue);
  padding-left: 4px;
}

.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid var(--card-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Floating Action / Back to Top */
.floating-actions {
  position: fixed;
  bottom: 30px;
  right: 30px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 99;
}

.floating-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: #ffffff;
  border: 1px solid var(--card-border);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  cursor: pointer;
  transition: all 0.25s ease;
  font-size: 1.1rem;
}

.floating-btn:hover {
  background: var(--frost-blue);
  color: #fff;
  transform: translateY(-3px);
}

.floating-cta {
  background: var(--frost-gradient);
  color: #fff !important;
  border: none;
  padding: 12px 20px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 0.9rem;
  box-shadow: var(--shadow-frost);
}

.floating-cta:hover {
  transform: translateY(-3px);
  filter: brightness(1.08);
}

/* ==========================================================================
   Article Detail Page Styles (2000-word Rich SEO Layout)
   ========================================================================== */
.article-header-section {
  padding: 60px 0 40px;
  background: linear-gradient(180deg, rgba(224, 242, 254, 0.4) 0%, rgba(248, 250, 252, 0) 100%);
  border-bottom: 1px solid rgba(226, 232, 240, 0.7);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

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

.breadcrumb a:hover {
  color: var(--frost-blue);
}

.article-main-title {
  font-size: 2.5rem;
  line-height: 1.3;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-container {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 40px;
  padding: 60px 0 100px;
}

.article-body {
  background: #ffffff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 44px;
  box-shadow: var(--shadow-sm);
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.article-body h2 {
  font-size: 1.7rem;
  margin: 40px 0 18px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--frost-ice);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-body h2::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 24px;
  background: var(--frost-gradient);
  border-radius: 3px;
}

.article-body h3 {
  font-size: 1.35rem;
  margin: 28px 0 14px;
  color: var(--text-primary);
}

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

.article-body ul, .article-body ol {
  margin: 0 0 24px 28px;
}

.article-body li {
  margin-bottom: 10px;
}

.article-body strong {
  color: var(--text-primary);
  font-weight: 700;
}

.article-callout {
  background: rgba(240, 249, 255, 0.8);
  border-left: 4px solid var(--frost-light);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 20px 24px;
  margin: 28px 0;
}

.article-callout.tip {
  background: rgba(236, 253, 245, 0.8);
  border-left-color: var(--accent-green);
}

.article-callout.warning {
  background: rgba(254, 242, 242, 0.8);
  border-left-color: var(--accent-red);
}

.callout-title {
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-table-wrap {
  overflow-x: auto;
  margin: 28px 0;
}

.article-table {
  width: 100%;
  border-collapse: collapse;
}

.article-table th, .article-table td {
  padding: 12px 16px;
  border: 1px solid var(--card-border);
  text-align: left;
}

.article-table th {
  background: rgba(241, 245, 249, 0.8);
  font-weight: 700;
  color: var(--text-primary);
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(224, 242, 254, 0.7), rgba(240, 249, 255, 0.9));
  border: 2px dashed rgba(56, 189, 248, 0.5);
  border-radius: var(--radius-md);
  padding: 28px;
  text-align: center;
  margin: 36px 0;
}

.article-cta-box h4 {
  font-size: 1.35rem;
  margin-bottom: 10px;
  color: var(--frost-blue);
}

.article-cta-box p {
  font-size: 0.95rem;
  margin-bottom: 18px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Sidebar */
.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.sidebar-widget {
  background: #ffffff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 96px;
}

.widget-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--card-border);
  color: var(--text-primary);
}

.toc-list {
  list-style: none;
}

.toc-list li {
  margin-bottom: 10px;
}

.toc-list a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  display: block;
}

.toc-list a:hover {
  color: var(--frost-blue);
  transform: translateX(4px);
}

.sidebar-promo-card {
  background: linear-gradient(135deg, #0284c7, #06b6d4);
  color: #fff;
  border-radius: var(--radius-md);
  padding: 26px 20px;
  text-align: center;
}

.sidebar-promo-card h4 {
  color: #fff;
  font-size: 1.25rem;
  margin-bottom: 10px;
}

.sidebar-promo-card p {
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.88rem;
  margin-bottom: 20px;
}

/* Responsive Media Queries */
@media (max-width: 1100px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid, .articles-grid, .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-metrics {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 868px) {
  .article-container {
    grid-template-columns: 1fr;
  }
  .sidebar-widget {
    position: static;
  }
  .navbar .nav-links, .navbar .nav-cta .btn-outline {
    display: none;
  }
  .mobile-toggle {
    display: block;
  }
  .hero-title {
    font-size: 2.3rem;
  }
  .section-title {
    font-size: 2rem;
  }
  .features-grid, .articles-grid, .reviews-grid, .pricing-grid {
    grid-template-columns: 1fr;
  }
  .pricing-card.popular {
    transform: none;
  }
  .pricing-card.popular:hover {
    transform: translateY(-6px);
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

/* Mobile Nav Drawer */
.mobile-nav-drawer {
  position: fixed;
  top: 74px;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--card-border);
  padding: 24px;
  display: none;
  flex-direction: column;
  gap: 16px;
  box-shadow: var(--shadow-lg);
  z-index: 99;
}

.mobile-nav-drawer.open {
  display: flex;
}

.mobile-nav-drawer a {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  padding: 10px 0;
  border-bottom: 1px solid rgba(226, 232, 240, 0.6);
}