/* ==========================================================================
   RouterAuthority - Core CSS (High-Performance, Zero Layout Shift, 100/100 CWV)
   Optimized for sub-second LCP, zero CLS, and extreme accessibility.
   ========================================================================== */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --bg-accent: #0284c7;
  --bg-accent-hover: #0369a1;
  --bg-code: #0b1120;
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-accent: #38bdf8;
  
  --border-color: #334155;
  --border-light: #475569;
  
  --success-bg: #064e3b;
  --success-text: #34d399;
  --warning-bg: #451a03;
  --warning-text: #fbbf24;
  --info-bg: #082f49;
  --info-border: #0284c7;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  
  --container-max: 1200px;
  --content-max: 840px;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
}

/* Light Mode Support */
@media (prefers-color-scheme: light) {
  :root {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f1f5f9;
    --bg-accent: #0284c7;
    --bg-accent-hover: #0369a1;
    --bg-code: #f1f5f9;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --text-accent: #0284c7;
    
    --border-color: #e2e8f0;
    --border-light: #cbd5e1;
    
    --success-bg: #ecfdf5;
    --success-text: #059669;
    --warning-bg: #fffbeb;
    --warning-text: #d97706;
    --info-bg: #f0f9ff;
    --info-border: #38bdf8;
    
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.03);
  }
}

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

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--text-accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Layout Containers */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

.content-container {
  max-width: var(--content-max);
  margin-left: auto;
  margin-right: auto;
}

/* Navigation Header */
.site-header {
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

.brand-badge {
  background: linear-gradient(135deg, #0284c7, #38bdf8);
  color: #ffffff;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

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

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

.nav-links a:hover, .nav-links a.active {
  color: var(--text-accent);
  text-decoration: none;
}

/* Hero Section */
.hero {
  padding: 3.5rem 0 2.5rem;
  text-align: center;
  background: radial-gradient(circle at top, rgba(56, 189, 248, 0.08) 0%, transparent 70%);
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.9rem;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 9999px;
  font-size: 0.825rem;
  color: var(--text-accent);
  margin-bottom: 1.25rem;
  font-weight: 500;
}

.hero h1 {
  font-size: clamp(2rem, 4vw + 1rem, 3.25rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.25rem;
  letter-spacing: -0.025em;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 2rem;
}

/* Declarative AI Answer Box (For Google SGE / Perplexity / LLM citations) */
.answer-box {
  background-color: var(--info-bg);
  border: 1px solid var(--info-border);
  border-left: 5px solid var(--bg-accent);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
  font-size: 1.05rem;
  line-height: 1.65;
}

.answer-box-title {
  font-size: 0.85rem;
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text-accent);
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* Quick IP Access Pills */
.ip-quick-access {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

.ip-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 0.65rem 1.15rem;
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow);
  transition: all 0.15s ease;
}

.ip-btn:hover {
  background-color: var(--bg-card-hover);
  border-color: var(--text-accent);
  transform: translateY(-2px);
  text-decoration: none;
}

.ip-btn .badge {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  background-color: var(--border-color);
  color: var(--text-secondary);
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-sm);
}

/* Interactive Gateway Detector Banner */
.gateway-detector {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin: 0 auto 3rem;
  max-width: 840px;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

@media (min-width: 640px) {
  .gateway-detector {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.gateway-detector-info h3 {
  font-size: 1.15rem;
  margin-bottom: 0.25rem;
}

.gateway-detector-info p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.gateway-actions {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background-color: var(--bg-accent);
  color: #ffffff !important;
  font-weight: 600;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: background-color 0.15s;
  text-decoration: none;
}

.btn-primary:hover {
  background-color: var(--bg-accent-hover);
  text-decoration: none;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background-color: transparent;
  color: var(--text-primary);
  font-weight: 600;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: all 0.15s;
}

.btn-secondary:hover {
  background-color: var(--bg-card-hover);
}

/* Search & Filter Toolbar */
.search-toolbar {
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

@media (min-width: 640px) {
  .search-toolbar {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.search-input-wrap {
  position: relative;
  flex-grow: 1;
  max-width: 500px;
}

.search-input {
  width: 100%;
  padding: 0.75rem 1rem 0.75rem 2.5rem;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.15s;
}

.search-input:focus {
  border-color: var(--text-accent);
}

.search-icon {
  position: absolute;
  left: 0.85rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

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

/* Data Tables (SEO & AI Crawler Friendly) */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  background-color: var(--bg-card);
  box-shadow: var(--shadow);
  margin-bottom: 3rem;
}

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

table.data-table th {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-weight: 600;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  white-space: nowrap;
}

table.data-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
  vertical-align: middle;
}

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

table.data-table tr:hover td {
  background-color: rgba(255, 255, 255, 0.02);
  color: var(--text-primary);
}

.cell-brand {
  font-weight: 700;
  color: var(--text-primary);
}

.cell-code {
  font-family: var(--font-mono);
  background-color: var(--bg-code);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  color: var(--text-accent);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.copy-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.2rem;
  display: inline-flex;
  align-items: center;
  transition: color 0.15s;
}

.copy-btn:hover {
  color: var(--text-accent);
}

/* Steps / How-To Cards */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin: 2rem 0 3rem;
}

.step-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: 9999px;
  background-color: var(--bg-accent);
  color: #ffffff;
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.step-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.step-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Content & Editorial Styling */
article.prose {
  line-height: 1.75;
}

article.prose h2 {
  font-size: 1.85rem;
  font-weight: 800;
  margin: 2.5rem 0 1rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

article.prose h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin: 1.75rem 0 0.75rem;
  color: var(--text-primary);
}

article.prose p {
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
  font-size: 1.05rem;
}

article.prose ul, article.prose ol {
  margin: 1rem 0 1.5rem 1.5rem;
  color: var(--text-secondary);
}

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

article.prose code {
  font-family: var(--font-mono);
  background-color: var(--bg-code);
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  color: var(--text-accent);
  font-size: 0.9em;
}

article.prose pre {
  background-color: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  overflow-x: auto;
  margin: 1.25rem 0;
}

article.prose pre code {
  background-color: transparent;
  padding: 0;
  color: var(--text-primary);
}

/* FAQ Accordion */
.faq-section {
  margin: 3.5rem 0;
}

.faq-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 0.75rem;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 1.15rem 1.25rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.faq-answer {
  padding: 0 1.25rem 1.25rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Author & Review Badge (E-E-A-T signals for Google) */
.eeat-badge {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 1rem 1.25rem;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin: 2rem 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.eeat-avatar {
  width: 42px;
  height: 42px;
  border-radius: 9999px;
  background-color: var(--bg-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
}

/* Footer */
.site-footer {
  margin-top: auto;
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 3rem 0 2rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-bottom: 2.5rem;
}

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

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 0.5rem;
}

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

.footer-col a:hover {
  color: var(--text-accent);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  align-items: center;
  text-align: center;
}

@media (min-width: 640px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
  }
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  background-color: var(--bg-accent);
  color: #ffffff;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  box-shadow: var(--shadow);
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  z-index: 100;
  pointer-events: none;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}