/* ==========================================================================
   NanoCloud Design System - "11｜云端极简白蓝"
   nano-cloud.rest Official Client Onboarding & Setup Portal
   ========================================================================== */

:root {
  /* Color Palette */
  --bg-body: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-subtle: #f1f5f9;
  --bg-glass: rgba(255, 255, 255, 0.88);

  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-active: #1e40af;
  --primary-light: #eff6ff;
  --primary-glow: rgba(37, 99, 235, 0.15);

  --sky: #0284c7;
  --sky-light: #e0f2fe;
  --sky-border: #bae6fd;

  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --accent-green-bg: #ecfdf5;
  --accent-amber: #d97706;
  --accent-amber-bg: #fffbeb;

  --text-main: #0f172a;
  --text-body: #334155;
  --text-muted: #64748b;
  --text-light: #94a3b8;

  --border-light: #e2e8f0;
  --border-medium: #cbd5e1;
  --border-primary: #93c5fd;

  /* Typography */
  --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, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.06), 0 2px 4px -2px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 10px 25px -5px rgba(37, 99, 235, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
  --shadow-xl: 0 20px 30px -10px rgba(37, 99, 235, 0.12), 0 10px 10px -5px rgba(15, 23, 42, 0.03);

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

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

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-body);
  color: var(--text-body);
  line-height: 1.75;
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(56, 189, 248, 0.05) 0%, transparent 40%),
    radial-gradient(circle at 90% 10%, rgba(37, 99, 235, 0.04) 0%, transparent 45%);
  background-attachment: fixed;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Containers */
.container {
  width: 100%;
  max-width: 1140px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

.container-narrow {
  max-width: 860px;
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

h1 {
  font-size: 1.85rem;
  margin-bottom: 1rem;
}

h2 {
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--sky-light);
}

h3 {
  font-size: 1.25rem;
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
}

p {
  margin-bottom: 1.15rem;
  color: var(--text-body);
  font-size: 1rem;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-hover);
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.02);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand-logo {
  height: 38px;
  width: auto;
  display: block;
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 1.5rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-body);
  padding: 0.4rem 0.2rem;
  position: relative;
  transition: color var(--transition-fast);
}

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

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--primary);
  border-radius: 2px;
}

.nav-cta-wrap {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Mobile Toggle */
.mobile-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 0.5rem;
  cursor: pointer;
  color: var(--text-main);
}

.mobile-toggle svg {
  display: block;
  width: 22px;
  height: 22px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-normal);
  line-height: 1.25;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--sky) 0%, var(--primary) 100%);
  color: #ffffff !important;
  box-shadow: 0 4px 14px var(--primary-glow);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #0369a1 0%, var(--primary-hover) 100%);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.25);
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: #ffffff;
  color: var(--primary) !important;
  border-color: var(--border-primary);
}

.btn-secondary:hover {
  background-color: var(--primary-light);
  border-color: var(--primary);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-body);
  border-color: var(--border-light);
}

.btn-outline:hover {
  background-color: #ffffff;
  border-color: var(--border-medium);
  color: var(--primary);
}

.btn-lg {
  padding: 0.85rem 1.85rem;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.85rem;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-blue {
  background-color: var(--primary-light);
  color: var(--primary);
  border: 1px solid var(--border-primary);
}

.badge-green {
  background-color: var(--accent-green-bg);
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.badge-amber {
  background-color: var(--accent-amber-bg);
  color: #92400e;
  border: 1px solid #fde68a;
}

/* Hero Section */
.hero-section {
  padding: 3.5rem 0 2.5rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2.5rem;
  align-items: center;
}

.hero-content {
  max-width: 600px;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2rem;
}

.hero-meta-points {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.85rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-light);
}

.meta-point {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-body);
}

.meta-icon {
  color: var(--primary);
  font-weight: bold;
}

.hero-media {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-media img,
.hero-media svg {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-xl);
}

/* Section Common */
.section {
  padding: 3.5rem 0;
}

.section-alt {
  background-color: #ffffff;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 2.5rem;
}

.section-header h2 {
  border-bottom: none;
  margin-top: 0;
  margin-bottom: 0.5rem;
}

.section-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 0;
}

/* Platform Cards Grid */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.platform-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.platform-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-primary);
}

.platform-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.platform-card h3 {
  margin-top: 0;
  font-size: 1.15rem;
  margin-bottom: 0.35rem;
}

.platform-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
  flex-grow: 1;
}

.platform-link {
  font-size: 0.875rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

/* Step Progression Cards */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.step-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  position: relative;
}

.step-number {
  display: inline-block;
  width: 32px;
  height: 32px;
  line-height: 32px;
  text-align: center;
  background: var(--primary);
  color: #ffffff;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.step-card h3 {
  margin-top: 0;
  font-size: 1.15rem;
}

.step-card p {
  font-size: 0.925rem;
  color: var(--text-body);
  margin-bottom: 0;
}

/* Callout Box */
.callout {
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
  margin: 1.5rem 0;
  border-left: 4px solid var(--primary);
  background: var(--primary-light);
}

.callout-title {
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.callout p:last-child {
  margin-bottom: 0;
}

.callout-amber {
  border-left-color: var(--accent-amber);
  background-color: var(--accent-amber-bg);
}

.callout-amber .callout-title {
  color: var(--accent-amber);
}

.callout-green {
  border-left-color: var(--accent-green);
  background-color: var(--accent-green-bg);
}

.callout-green .callout-title {
  color: #047857;
}

/* Article Cards */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
}

.article-card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--border-primary);
  transform: translateY(-2px);
}

.article-card-tag {
  margin-bottom: 0.75rem;
}

.article-card h3 {
  font-size: 1.1rem;
  line-height: 1.45;
  margin-top: 0;
  margin-bottom: 0.75rem;
}

.article-card h3 a {
  color: var(--text-main);
}

.article-card h3 a:hover {
  color: var(--primary);
}

.article-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  flex-grow: 1;
  margin-bottom: 1.25rem;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.825rem;
  color: var(--text-light);
  border-top: 1px solid var(--border-light);
  padding-top: 0.75rem;
}

/* Article Detail Layout */
.article-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 2.5rem;
  padding: 2.5rem 0 4rem;
  align-items: start;
}

.article-sidebar {
  position: sticky;
  top: 90px;
  background: #ffffff;
  padding: 1.25rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
}

.toc-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-light);
}

.toc-list {
  list-style: none;
  font-size: 0.875rem;
}

.toc-list li {
  margin-bottom: 0.5rem;
}

.toc-list a {
  color: var(--text-muted);
  display: block;
  line-height: 1.4;
}

.toc-list a:hover {
  color: var(--primary);
}

.article-body {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
}

.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-top: 1rem;
}

.article-content {
  font-size: 1.025rem;
  line-height: 1.85;
}

.article-content h2 {
  font-size: 1.4rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

.article-content h3 {
  font-size: 1.2rem;
  margin-top: 1.75rem;
}

.article-content ul,
.article-content ol {
  margin-left: 1.5rem;
  margin-bottom: 1.25rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

.geo-answer {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 1rem;
  font-weight: 500;
  color: #1e3a8a;
  margin-bottom: 1.25rem;
}

/* Data Tables */
.data-table-wrap {
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.925rem;
}

.data-table th,
.data-table td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border-light);
}

.data-table th {
  background-color: var(--bg-card-subtle);
  color: var(--text-main);
  font-weight: 600;
}

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

.data-table tr:hover td {
  background-color: #fafbfc;
}

/* FAQ Accordion (Pure HTML/CSS details & summary for SEO) */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item[open] {
  border-color: var(--border-primary);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  padding: 1.15rem 1.25rem;
  font-weight: 600;
  font-size: 1.025rem;
  color: var(--text-main);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

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

.faq-question::after {
  content: "+";
  font-size: 1.25rem;
  color: var(--primary);
  font-weight: 400;
  transition: transform var(--transition-fast);
}

.faq-item[open] .faq-question::after {
  content: "−";
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 1.25rem 1.25rem;
  color: var(--text-body);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-answer p:last-child {
  margin-bottom: 0;
}

/* Feedback & Form Section */
.feedback-box {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 2rem;
  max-width: 680px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.4rem;
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  font-family: inherit;
  font-size: 0.95rem;
  background-color: #fafbfc;
  color: var(--text-main);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
  background-color: #ffffff;
}

/* Breadcrumbs */
.breadcrumbs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.breadcrumbs a {
  color: var(--text-muted);
}

.breadcrumbs a:hover {
  color: var(--primary);
}

.breadcrumbs span.sep {
  color: var(--text-light);
}

/* Bottom CTA Banner */
.cta-banner {
  background: linear-gradient(135deg, #eff6ff 0%, #e0f2fe 100%);
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-xl);
  padding: 3rem 2rem;
  text-align: center;
  margin: 3.5rem 0;
  position: relative;
  overflow: hidden;
}

.cta-banner h2 {
  font-size: 1.85rem;
  margin-top: 0;
  margin-bottom: 0.75rem;
  border-bottom: none;
}

.cta-banner p {
  max-width: 620px;
  margin: 0 auto 1.75rem;
  color: var(--text-body);
}

/* Footer */
.site-footer {
  background: #ffffff;
  border-top: 1px solid var(--border-light);
  padding: 3.5rem 0 2rem;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
  letter-spacing: 0.02em;
}

.footer-links {
  list-style: none;
  font-size: 0.875rem;
}

.footer-links li {
  margin-bottom: 0.6rem;
}

.footer-links a {
  color: var(--text-muted);
}

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

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--border-light);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-size: 0.825rem;
  color: var(--text-light);
}

.disclaimer-box {
  background: var(--bg-card-subtle);
  border-radius: var(--radius-md);
  padding: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-top: 1.5rem;
}

/* Responsive Media Queries */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .hero-media {
    order: -1;
    max-width: 440px;
    margin: 0 auto;
  }
  .platform-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .article-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .article-layout {
    grid-template-columns: 1fr;
  }
  .article-sidebar {
    position: static;
    margin-bottom: 1.5rem;
  }
  .footer-grid {
    grid-template-columns: 1.2fr 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: #ffffff;
    flex-direction: column;
    padding: 1.5rem;
    box-shadow: var(--shadow-xl);
    border-bottom: 1px solid var(--border-light);
    gap: 1rem;
  }
  .nav-menu.open {
    display: flex;
  }
  .mobile-toggle {
    display: block;
  }
  .steps-grid {
    grid-template-columns: 1fr;
  }
  .platform-grid {
    grid-template-columns: 1fr;
  }
  .article-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .hero-meta-points {
    grid-template-columns: 1fr;
  }
  .article-body {
    padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .btn {
    width: 100%;
  }
}