/* ==========================================================================
   OuO Network - Swiss-Rationalist Typographic Deconstruction Monochrome UI
   Stark Gallery Palette | 1px Architectural Datum Lines | Graphicless Flat Purism
   ========================================================================== */

:root {
  /* Stark Gallery Palette - Light Mode (Default) */
  --bg-primary: #ffffff;
  --bg-secondary: #fbfbfb;
  --bg-invert: #000000;
  
  --text-primary: #000000;
  --text-secondary: #444444;
  --text-muted: #777777;
  --text-invert: #ffffff;
  
  --line-strong: #000000;
  --line-hairline: #e0e0e0;
  --line-datum: #000000;
  
  --font-mono: ui-monospace, "SF Mono", "Menlo", "Consolas", "Liberation Mono", monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Arial", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  
  --header-height: 64px;
}

[data-theme="dark"] {
  /* Stark Gallery Palette - Dark Mode (Inverted Pure Carbon) */
  --bg-primary: #000000;
  --bg-secondary: #0a0a0a;
  --bg-invert: #ffffff;
  
  --text-primary: #ffffff;
  --text-secondary: #cccccc;
  --text-muted: #888888;
  --text-invert: #000000;
  
  --line-strong: #ffffff;
  --line-hairline: #222222;
  --line-datum: #ffffff;
}

/* ==========================================================================
   Universal Reset & Grid Foundation
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 15px;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.55;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.2s ease, color 0.2s ease;
}

/* Architectural Hairline Canvas Overlay */
.hairline-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.monumental-ouo-vector {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 1200px;
  height: 600px;
  transform: translate(-50%, -50%);
  opacity: 0.04;
  pointer-events: none;
  transition: transform 0.1s cubic-bezier(0.2, 0, 0.2, 1);
  will-change: transform;
}

[data-theme="dark"] .monumental-ouo-vector {
  opacity: 0.08;
}

.hairline-grid-lines {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(to right, var(--line-hairline) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-hairline) 1px, transparent 1px);
  background-size: 80px 80px;
  opacity: 0.4;
}

/* Container Structure */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* ==========================================================================
   Header & Swiss Navigation
   ========================================================================== */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--line-strong);
  height: var(--header-height);
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 800;
  letter-spacing: -0.5px;
}

.brand-logo-img {
  height: 34px;
  width: auto;
  display: block;
  border-radius: 6px;
  transition: transform 0.15s ease, opacity 0.15s ease;
  object-fit: contain;
}

.brand-logo-img:hover {
  transform: scale(1.03);
}

.brand-monogram {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  border: 1px solid var(--line-strong);
  padding: 3px 8px;
  letter-spacing: 2px;
  background: var(--bg-primary);
  font-weight: 700;
}

.brand-name {
  font-size: 1.15rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}

/* Nav Menu */
.nav {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 0;
  border-left: 1px solid var(--line-hairline);
  border-right: 1px solid var(--line-hairline);
  height: 100%;
}

.nav-item {
  display: inline-flex;
  align-items: center;
  height: var(--header-height);
  padding: 0 16px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  border-right: 1px solid var(--line-hairline);
  transition: none; /* Instantaneous 0ms optical feedback */
  position: relative;
  white-space: nowrap;
}

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

/* Instantaneous Inversion on Hover */
.nav-item:hover,
.nav-item.active {
  background-color: var(--bg-invert);
  color: var(--text-invert);
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* Refined Architectural Theme Switcher */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-primary);
  border: 1px solid var(--line-strong);
  padding: 7px 12px;
  cursor: pointer;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  transition: none;
  user-select: none;
}

.theme-toggle:hover {
  background-color: var(--bg-invert);
  color: var(--text-invert);
}

.theme-indicator {
  width: 8px;
  height: 8px;
  border: 1px solid currentColor;
  background: currentColor;
}

[data-theme="dark"] .theme-indicator {
  background: transparent;
}

/* ==========================================================================
   Analog Letterpress Stamp Buttons (Pure Monastic Purism)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 700;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 9px 20px;
  cursor: pointer;
  border: 1px solid var(--line-strong);
  transition: transform 0.05s ease, box-shadow 0.05s ease;
  user-select: none;
  white-space: nowrap;
}

/* Analog Letterpress Stamp Depression */
.btn-stamp {
  background-color: var(--bg-invert);
  color: var(--text-invert) !important;
  box-shadow: 3px 3px 0 var(--line-strong);
}

.btn-stamp:hover {
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 var(--line-strong);
}

.btn-stamp:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--line-strong);
}

.btn-outline {
  background-color: var(--bg-primary);
  color: var(--text-primary) !important;
  box-shadow: 3px 3px 0 var(--line-strong);
}

.btn-outline:hover {
  background-color: var(--bg-invert);
  color: var(--text-invert) !important;
}

.btn-outline:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--line-strong);
}

.btn-lg {
  padding: 13px 28px;
  font-size: 0.95rem;
}

.btn-block {
  width: 100%;
}

.btn-text-action {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--text-primary);
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 2px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.btn-text-action:hover {
  background-color: var(--bg-invert);
  color: var(--text-invert);
}

/* ==========================================================================
   Typography & Datum Elements
   ========================================================================== */
.datum-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 14px;
  display: block;
}

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

/* ==========================================================================
   Hero Section: Monumental Typography & Introduction
   ========================================================================== */
.hero-section {
  padding: 70px 0 60px;
  border-bottom: 1px solid var(--line-hairline);
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 48px;
  align-items: start;
}

.hero-headline {
  font-size: 3.3rem;
  line-height: 1.08;
  letter-spacing: -0.04em;
  font-weight: 900;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.hero-subtitle {
  font-size: 1.3rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  margin-bottom: 20px;
  border-left: 2px solid var(--line-strong);
  padding-left: 16px;
}

.hero-intro {
  font-size: 0.98rem;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 34px;
  max-width: 620px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* Hero Monospace Spec Board */
.hero-spec-board {
  border: 1px solid var(--line-strong);
  background: var(--bg-primary);
  font-family: var(--font-mono);
}

.spec-header {
  background: var(--bg-invert);
  color: var(--text-invert);
  padding: 10px 16px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 1px;
  display: flex;
  justify-content: space-between;
}

.spec-body {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.spec-row {
  display: flex;
  justify-content: space-between;
  border-bottom: 1px dashed var(--line-hairline);
  padding-bottom: 8px;
  font-size: 0.85rem;
}

.spec-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.spec-key {
  color: var(--text-muted);
}

.spec-val {
  font-weight: 700;
}

/* ==========================================================================
   Section Foundation
   ========================================================================== */
.section {
  padding: 70px 0;
  border-bottom: 1px solid var(--line-hairline);
  position: relative;
}

.section-head {
  margin-bottom: 44px;
}

.section-title {
  font-size: 2.1rem;
  font-weight: 850;
  letter-spacing: -0.03em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 760px;
  line-height: 1.6;
}

/* ==========================================================================
   Core Advantages (3 Graphicless Architectural Cards)
   ========================================================================== */
.architectural-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line-strong);
  border-left: 1px solid var(--line-strong);
}

.arch-card {
  border-right: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  padding: 36px 30px;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: none; /* Instantaneous 0ms optical feedback */
}

/* Instantaneous Optical Inversion on Hover */
.arch-card:hover {
  background-color: var(--bg-invert);
  color: var(--text-invert);
}

.arch-card:hover .arch-num,
.arch-card:hover .arch-title,
.arch-card:hover .arch-desc,
.arch-card:hover .arch-list li,
.arch-card:hover .arch-tech-stamp {
  color: var(--text-invert) !important;
}

.arch-card:hover .arch-list li {
  border-color: rgba(255, 255, 255, 0.2);
}

.arch-num {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--text-muted);
}

.arch-title {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  line-height: 1.3;
}

.arch-desc {
  font-size: 0.94rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 24px;
  flex-grow: 1;
}

.arch-list {
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  margin-bottom: 20px;
}

.arch-list li {
  border-top: 1px solid var(--line-hairline);
  padding: 8px 0;
  color: var(--text-secondary);
}

.arch-tech-stamp {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 1px;
  color: var(--text-muted);
  border-top: 1px solid var(--line-strong);
  padding-top: 12px;
  text-transform: uppercase;
}

/* ==========================================================================
   Monospace Latency & Node Routing Table (Monumental "O u O" Framing)
   ========================================================================== */
.latency-framing-container {
  position: relative;
  border: 1px solid var(--line-strong);
  background: var(--bg-primary);
  margin-top: 20px;
}

.latency-framing-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 0.84rem;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
}

.latency-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  text-align: left;
}

.latency-table th {
  padding: 12px 18px;
  border-bottom: 1px solid var(--line-strong);
  background: var(--bg-secondary);
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.5px;
  color: var(--text-muted);
}

.latency-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--line-hairline);
  color: var(--text-primary);
}

/* 0ms Instantaneous Optical Inversion on Table Row Hover */
.latency-table tbody tr {
  transition: none;
  cursor: crosshair;
}

.latency-table tbody tr:hover {
  background-color: var(--bg-invert);
}

.latency-table tbody tr:hover td {
  color: var(--text-invert);
}

.tag-status-up {
  display: inline-block;
  padding: 2px 6px;
  border: 1px solid currentColor;
  font-size: 0.72rem;
  font-weight: 700;
}

/* ==========================================================================
   Showcase: Streaming & AI Support (Graphicless Typographic Cards)
   ========================================================================== */
.showcase-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line-strong);
}

.showcase-block {
  padding: 40px 36px;
  display: flex;
  flex-direction: column;
  background: var(--bg-primary);
}

.showcase-block:first-child {
  border-right: 1px solid var(--line-strong);
}

.showcase-headline {
  font-size: 1.55rem;
  font-weight: 850;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}

.showcase-intro {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.monochrome-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: auto;
}

.mono-chip {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 8px 14px;
  border: 1px solid var(--line-strong);
  background: var(--bg-primary);
  color: var(--text-primary);
  transition: none; /* Instant optical snap */
  cursor: default;
}

.mono-chip:hover {
  background-color: var(--bg-invert);
  color: var(--text-invert);
}

/* ==========================================================================
   Pricing Table: Real-World Benchmark Pricing
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line-strong);
  border-left: 1px solid var(--line-strong);
  margin-bottom: 48px;
}

.pricing-box {
  border-right: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  padding: 38px 30px;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: none;
}

.pricing-box.popular {
  background: var(--bg-secondary);
}

.popular-banner {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 1px;
  background: var(--bg-invert);
  color: var(--text-invert);
  padding: 4px 10px;
  display: inline-block;
  margin-bottom: 16px;
  align-self: flex-start;
}

.pricing-tier {
  font-size: 1.45rem;
  font-weight: 850;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

.pricing-subtitle {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 22px;
}

.price-display {
  display: flex;
  align-items: baseline;
  gap: 4px;
  font-family: var(--font-mono);
  margin-bottom: 24px;
  border-bottom: 1px solid var(--line-hairline);
  padding-bottom: 18px;
}

.price-curr {
  font-size: 1.3rem;
  font-weight: 700;
}

.price-val {
  font-size: 2.85rem;
  font-weight: 900;
  letter-spacing: -1.5px;
}

.price-freq {
  font-size: 0.84rem;
  color: var(--text-muted);
}

.pricing-features {
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  line-height: 1.6;
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-features li {
  padding: 9px 0;
  border-bottom: 1px dashed var(--line-hairline);
  color: var(--text-secondary);
}

.pricing-features li strong {
  color: var(--text-primary);
}

/* Feature Specification Comparison Matrix */
.matrix-container {
  border: 1px solid var(--line-strong);
  margin-top: 28px;
}

.matrix-header {
  padding: 14px 20px;
  background: var(--bg-invert);
  color: var(--text-invert);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
}

.matrix-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.84rem;
}

.matrix-table th,
.matrix-table td {
  padding: 12px 18px;
  border-bottom: 1px solid var(--line-hairline);
  text-align: left;
}

.matrix-table th {
  background: var(--bg-secondary);
  font-weight: 700;
  border-bottom: 1px solid var(--line-strong);
}

.matrix-table tbody tr:hover {
  background: var(--bg-secondary);
}

/* ==========================================================================
   User Reviews (Testimonials)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line-strong);
  border-left: 1px solid var(--line-strong);
}

.review-item {
  border-right: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  padding: 32px 28px;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
}

.review-quote {
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 24px;
  flex-grow: 1;
}

.review-footer {
  border-top: 1px solid var(--line-hairline);
  padding-top: 16px;
  font-family: var(--font-mono);
}

.review-author {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
}

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

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-list {
  border-top: 1px solid var(--line-strong);
}

.faq-entry {
  border-bottom: 1px solid var(--line-strong);
  background: var(--bg-primary);
}

.faq-summary {
  padding: 22px 20px;
  font-size: 1.05rem;
  font-weight: 750;
  letter-spacing: -0.01em;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
  font-family: var(--font-sans);
}

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

.faq-summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 400;
  line-height: 1;
  margin-left: 16px;
}

.faq-entry[open] .faq-summary::after {
  content: "–";
}

.faq-entry[open] .faq-summary {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--line-hairline);
}

.faq-content {
  padding: 20px 20px 24px;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--text-secondary);
}

/* ==========================================================================
   Footer: Strictly Only Four Titles
   ========================================================================== */
.footer {
  border-top: 1px solid var(--line-strong);
  background: var(--bg-primary);
  padding: 36px 0;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  list-style: none;
  gap: 0;
  border: 1px solid var(--line-strong);
  max-width: 720px;
  margin: 0 auto;
}

.footer-nav li {
  flex: 1;
  text-align: center;
  border-right: 1px solid var(--line-strong);
}

.footer-nav li:last-child {
  border-right: none;
}

.footer-nav a {
  display: block;
  padding: 14px 10px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  font-family: var(--font-sans);
  transition: none; /* Instantaneous optical inversion */
}

.footer-nav a:hover {
  background-color: var(--bg-invert);
  color: var(--text-invert);
}

/* ==========================================================================
   Sub-Pages Common (about, terms, privacy, sitemap, insights)
   ========================================================================== */
.section-hero-sub {
  padding: 60px 0 40px;
  border-bottom: 1px solid var(--line-strong);
  background: var(--bg-secondary);
}

.hero-title-sub {
  font-size: 2.5rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.arch-document {
  max-width: 900px;
  margin: 0 auto;
  border: 1px solid var(--line-strong);
  background: var(--bg-primary);
  padding: 48px;
}

.arch-document h2 {
  font-size: 1.5rem;
  font-weight: 850;
  letter-spacing: -0.02em;
  margin: 32px 0 16px;
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 10px;
}

.arch-document h2:first-of-type {
  margin-top: 0;
}

.arch-document p {
  font-size: 0.96rem;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 18px;
}

.arch-document ul,
.arch-document ol {
  font-size: 0.95rem;
  line-height: 1.8;
  padding-left: 24px;
  margin-bottom: 22px;
  color: var(--text-secondary);
}

.arch-document li {
  margin-bottom: 8px;
}

.arch-callout {
  border: 1px solid var(--line-strong);
  background: var(--bg-secondary);
  padding: 18px 22px;
  margin: 24px 0;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.6;
}

/* Articles Layout (insights-9x7a.html) */
.articles-layout {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line-strong);
  margin-bottom: 40px;
}

.article-row {
  display: grid;
  grid-template-columns: 160px 1fr 140px;
  gap: 24px;
  padding: 30px 24px;
  border-bottom: 1px solid var(--line-hairline);
  align-items: start;
}

.article-row:last-child {
  border-bottom: none;
}

.article-row:hover {
  background: var(--bg-secondary);
}

.article-meta {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.mono-date {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.article-title {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
}

.article-title a {
  color: var(--text-primary);
  text-decoration: none;
}

.article-title a:hover {
  text-decoration: underline;
}

.article-summary {
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.article-tags {
  display: flex;
  gap: 8px;
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  border: 1px solid var(--line-hairline);
  padding: 2px 8px;
  color: var(--text-muted);
}

.article-action {
  text-align: right;
  padding-top: 4px;
}

.banner-box {
  border: 1px solid var(--line-strong);
  background: var(--bg-secondary);
  padding: 40px;
  text-align: center;
}

.banner-title {
  font-size: 1.6rem;
  font-weight: 850;
  margin: 12px 0 10px;
}

.banner-desc {
  font-size: 0.98rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

/* ==========================================================================
   Responsive Media Queries (@media)
   Strict Mobile Single-Column & Touch Target Optimization
   ========================================================================== */
@media (max-width: 1080px) {
  .nav {
    display: none; /* Mobile Drawer / Single-column priority */
  }
}

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  
  .architectural-grid-3,
  .pricing-grid,
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  
  .showcase-grid {
    grid-template-columns: 1fr;
  }
  
  .showcase-block:first-child {
    border-right: none;
    border-bottom: 1px solid var(--line-strong);
  }
  
  .hero-headline {
    font-size: 2.6rem;
  }
  
  .article-row {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .article-action {
    text-align: left;
  }
}

@media (max-width: 640px) {
  .hero-headline {
    font-size: 2.15rem;
  }
  
  .hero-subtitle {
    font-size: 1.1rem;
  }
  
  .section-title {
    font-size: 1.7rem;
  }
  
  .arch-document {
    padding: 24px 18px;
  }
  
  .footer-nav {
    flex-direction: column;
  }
  
  .footer-nav li {
    border-right: none;
    border-bottom: 1px solid var(--line-strong);
  }
  
  .footer-nav li:last-child {
    border-bottom: none;
  }
  
  .btn-lg {
    width: 100%;
    padding: 14px 20px;
  }
}

/* ==========================================================================
   Article Deep Reader & Long-Form SEO Typography
   ========================================================================== */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--text-secondary);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--text-primary);
  text-decoration: underline;
}

.article-header {
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 28px;
  margin-bottom: 36px;
}

.article-h1 {
  font-size: 2.6rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.03em;
  margin: 14px 0 18px;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-wrap: wrap;
}

.article-toc {
  border: 1px solid var(--line-strong);
  background: var(--bg-secondary);
  padding: 24px 28px;
  margin: 32px 0 44px;
}

.toc-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 800;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.toc-list li a {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text-primary);
  text-decoration: none;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  line-height: 1.5;
}

.toc-list li a:hover {
  text-decoration: underline;
}

.article-prose {
  font-size: 1.02rem;
  line-height: 1.85;
  color: var(--text-primary);
}

.article-prose h2 {
  font-size: 1.7rem;
  font-weight: 850;
  letter-spacing: -0.02em;
  margin: 48px 0 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line-strong);
}

.article-prose h3 {
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 32px 0 14px;
}

.article-prose p {
  color: var(--text-secondary);
  margin-bottom: 22px;
}

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

.article-prose ul, .article-prose ol {
  padding-left: 24px;
  margin-bottom: 24px;
  color: var(--text-secondary);
}

.article-prose li {
  margin-bottom: 10px;
  line-height: 1.75;
}

.article-callout-box {
  border: 1px solid var(--line-strong);
  border-left: 4px solid var(--line-strong);
  background: var(--bg-secondary);
  padding: 20px 24px;
  margin: 28px 0;
  font-size: 0.95rem;
}

.article-cta-banner {
  border: 2px solid var(--line-strong);
  background: var(--bg-secondary);
  padding: 36px 30px;
  margin: 50px 0;
  text-align: center;
}

.article-faq-section {
  margin-top: 56px;
  border-top: 2px solid var(--line-strong);
  padding-top: 36px;
}

.related-articles-section {
  margin-top: 56px;
  border-top: 2px solid var(--line-strong);
  padding-top: 36px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 20px;
}

.related-card {
  border: 1px solid var(--line-strong);
  padding: 22px;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
}

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

.related-card h4 {
  font-size: 1.05rem;
  font-weight: 750;
  margin-bottom: 8px;
}

.related-card a {
  color: var(--text-primary);
  text-decoration: none;
}

.related-card p {
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--text-muted);
  margin-bottom: 14px;
  flex-grow: 1;
}

@media (max-width: 768px) {
  .article-h1 {
    font-size: 2rem;
  }
  .related-grid {
    grid-template-columns: 1fr;
  }
}