/* ==========================================================================
   SUFE — Monochrome Editorial Design System
   Palette:
     - Background: #FAFAFA (高洁暖白)
     - Text Primary: #000000 (纯黑)
     - Text Secondary: #737373 (中度冷灰)
     - Card Surface: #F0F0EE (极淡暖灰)
   ========================================================================== */

:root {
  --bg-page: #FAFAFA;
  --bg-card: #F0F0EE;
  --bg-card-hover: #E7E7E4;
  --text-primary: #000000;
  --text-secondary: #737373;
  --border-hairline: rgba(0, 0, 0, 0.12);
  --border-subtle: rgba(0, 0, 0, 0.06);
  --border-strong: rgba(0, 0, 0, 0.85);
  --accent-black: #000000;
  --accent-white: #FFFFFF;

  --font-display: 'Cormorant Garamond', 'Noto Serif SC', 'Songti SC', Georgia, serif;
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --ease-editorial: cubic-bezier(0.22, 1, 0.36, 1);
  --nav-height: 68px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 28px);
  background-color: var(--bg-page);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--bg-page);
  color: var(--text-primary);
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Kinetic Monochrome Background Canvas */
#editorial-bg {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
}

/* Subtle archival paper grain */
.paper-grain {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.028;
  background-image: radial-gradient(rgba(0, 0, 0, 0.75) 0.5px, transparent 0.5px);
  background-size: 3px 3px;
}

/* Main Foreground Layer */
.site-shell {
  position: relative;
  z-index: 2;
}

/* Central Editorial Spine — 25%+ Breathing Whitespace on Both Sides on Desktop */
.editorial-spine {
  width: min(880px, 50vw);
  margin-inline: auto;
}

@media (max-width: 1280px) {
  .editorial-spine {
    width: min(760px, 66vw);
  }
}

@media (max-width: 960px) {
  .editorial-spine {
    width: calc(100% - 48px);
  }
}

@media (max-width: 600px) {
  .editorial-spine {
    width: calc(100% - 32px);
  }
}

/* Links & Buttons Reset */
a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

/* ==========================================================================
   Navigation Bar
   ========================================================================== */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--nav-height);
  background: rgba(250, 250, 250, 0.86);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-inner {
  width: min(1240px, 90vw);
  height: 100%;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand-mark {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  white-space: nowrap;
}

.brand-word {
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.brand-edition {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-secondary);
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  transition: color 0.25s ease;
  white-space: nowrap;
  position: relative;
  padding-block: 4px;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background: var(--text-primary);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.3s var(--ease-editorial);
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--text-primary);
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after {
  transform: scaleX(1);
  transform-origin: left;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: 999px;
  background: var(--accent-black);
  color: var(--accent-white);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  white-space: nowrap;
  transition: transform 0.25s var(--ease-editorial), opacity 0.25s ease;
}

.nav-cta:hover {
  transform: translateY(-1px);
  opacity: 0.88;
}

.nav-toggle {
  display: none;
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-hairline);
  border-radius: 999px;
}

@media (max-width: 1024px) {
  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(250, 250, 250, 0.98);
    backdrop-filter: blur(16px);
    flex-direction: column;
    align-items: flex-start;
    padding: 24px 6vw 32px;
    gap: 18px;
    border-bottom: 1px solid var(--border-hairline);
  }

  .nav-links.is-open {
    display: flex;
  }

  .nav-toggle {
    display: inline-flex;
  }
}

/* ==========================================================================
   Top Editorial Masthead / Ad Slogan Banner
   ========================================================================== */
.masthead-strip {
  padding-top: 28px;
  padding-bottom: 12px;
}

.masthead-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding: 14px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
}

.masthead-slogan {
  font-size: 0.84rem;
  letter-spacing: 0.03em;
  color: var(--text-primary);
  font-weight: 500;
}

.masthead-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
  letter-spacing: 0.04em;
}

/* ==========================================================================
   Hero Section (Monochrome Editorial Centerpiece)
   ========================================================================== */
.hero-section {
  min-height: calc(82vh - var(--nav-height));
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding-block: 64px 72px;
}

.hero-kicker {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.hero-display {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 4.4vw, 4.75rem);
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: 0.06em;
  color: var(--text-primary);
  white-space: nowrap;
  margin-bottom: 32px;
}

@media (max-width: 640px) {
  .hero-display {
    font-size: clamp(1.9rem, 9vw, 2.8rem);
    white-space: normal;
  }
}

.hero-hairline {
  width: 100%;
  height: 1px;
  background: var(--border-hairline);
  margin-bottom: 36px;
}

.pill-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 15px 38px;
  border-radius: 999px;
  background: var(--accent-black);
  color: var(--accent-white);
  font-size: 0.92rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  transition: transform 0.35s var(--ease-editorial), box-shadow 0.35s var(--ease-editorial), opacity 0.25s ease;
}

.pill-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.14);
}

.pill-cta .arrow {
  display: inline-block;
  font-family: var(--font-sans);
  transition: transform 0.3s var(--ease-editorial);
}

.pill-cta:hover .arrow {
  transform: translateX(4px);
}

.hero-caption {
  margin-top: 28px;
  max-width: 540px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ==========================================================================
   Section Scaffolding & Editorial Headers
   ========================================================================== */
.editorial-section {
  padding-block: 88px;
  border-top: 1px solid var(--border-subtle);
}

.section-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px 24px;
  margin-bottom: 48px;
}

.section-index {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--text-secondary);
  text-transform: uppercase;
  display: block;
  margin-bottom: 10px;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 2.8vw, 2.75rem);
  font-weight: 500;
  letter-spacing: 0.03em;
  line-height: 1.2;
}

.section-subtitle {
  max-width: 420px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

/* Scroll Reveal Animation */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.8s var(--ease-editorial), transform 0.8s var(--ease-editorial);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Staggered Editorial Spread (Text Left / Metric Right + Macro Plate)
   ========================================================================== */
.editorial-spread {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px 56px;
  align-items: start;
  margin-bottom: 56px;
}

.spread-left {
  text-align: left;
  padding-right: 12px;
}

.spread-right {
  text-align: right;
  padding-left: 12px;
  margin-top: 40px;
}

.spread-prose-title {
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 500;
  margin-bottom: 14px;
  line-height: 1.35;
}

.spread-prose-body {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.85;
}

.metric-monolith {
  display: inline-block;
  text-align: right;
  padding: 28px 32px;
  background: var(--bg-card);
  border-right: 2px solid var(--text-primary);
}

.metric-value {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 3.6vw, 3.5rem);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}

.metric-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

@media (max-width: 768px) {
  .editorial-spread {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .spread-right {
    margin-top: 0;
    text-align: left;
    padding-left: 0;
  }

  .metric-monolith {
    display: block;
    text-align: left;
    border-right: none;
    border-left: 2px solid var(--text-primary);
  }
}

/* Monochrome Editorial Hardware Still-life Plate */
.editorial-plate {
  margin-block: 48px;
  background: var(--bg-card);
  padding: 18px;
  border: 1px solid var(--border-subtle);
}

.editorial-plate img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  filter: grayscale(100%) contrast(1.06);
}

.plate-caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
  letter-spacing: 0.06em;
}

/* ==========================================================================
   Section 3: Node Latency & Real-Time Status Grid
   ========================================================================== */
.node-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 20px;
  background: var(--bg-card);
  margin-bottom: 16px;
}

.node-summary {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-primary);
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--text-primary);
  display: inline-block;
  animation: pulse-dot 2.4s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.35; transform: scale(0.85); }
}

.refresh-btn {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  padding: 6px 14px;
  border: 1px solid var(--border-hairline);
  border-radius: 999px;
  transition: background 0.25s ease, color 0.25s ease;
}

.refresh-btn:hover {
  background: var(--accent-black);
  color: var(--accent-white);
  border-color: var(--accent-black);
}

.node-table {
  border-top: 1px solid var(--border-hairline);
}

.node-row {
  display: grid;
  grid-template-columns: 1.6fr 1.2fr 0.8fr 0.8fr 0.9fr;
  align-items: center;
  gap: 16px;
  padding: 18px 8px;
  border-bottom: 1px solid var(--border-subtle);
  transition: background 0.25s ease;
}

.node-row:hover {
  background: rgba(240, 240, 238, 0.55);
}

.node-name {
  font-weight: 500;
  font-size: 0.94rem;
}

.node-route {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--text-secondary);
}

.node-latency {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  font-weight: 500;
  text-align: right;
}

.node-load {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--text-secondary);
  text-align: right;
}

.node-badge {
  justify-self: end;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  background: var(--bg-card);
  color: var(--text-primary);
}

@media (max-width: 768px) {
  .node-row {
    grid-template-columns: 1fr auto;
    gap: 6px 12px;
    padding: 16px 4px;
  }

  .node-route {
    grid-column: 1 / 2;
  }

  .node-load {
    display: none;
  }

  .node-badge {
    grid-column: 2 / 3;
    grid-row: 2 / 3;
  }
}

/* ==========================================================================
   Section 4A: Pricing Accordion (Ultra-flat Editorial Accordion)
   ========================================================================== */
.pricing-accordion {
  border-top: 1px solid var(--text-primary);
}

.plan-item {
  border-bottom: 1px solid var(--border-hairline);
}

.plan-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 6px;
  text-align: left;
  transition: background 0.25s ease;
}

.plan-trigger:hover {
  background: rgba(240, 240, 238, 0.45);
}

.plan-title-group {
  display: flex;
  align-items: baseline;
  gap: 18px;
}

.plan-num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
}

.plan-name {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.1vw, 1.9rem);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.plan-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  padding: 3px 9px;
  background: var(--bg-card);
  color: var(--text-secondary);
  letter-spacing: 0.06em;
}

.plan-price-group {
  display: flex;
  align-items: baseline;
  gap: 18px;
}

.plan-price {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 2.4vw, 2.2rem);
  font-weight: 500;
  white-space: nowrap;
}

.plan-price small {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--text-secondary);
  font-weight: 400;
  margin-left: 4px;
}

.plan-icon {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--text-secondary);
  transition: transform 0.35s var(--ease-editorial);
}

.plan-item.is-open .plan-icon {
  transform: rotate(45deg);
  color: var(--text-primary);
}

.plan-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.42s var(--ease-editorial);
}

.plan-item.is-open .plan-panel {
  grid-template-rows: 1fr;
}

.plan-panel-inner {
  overflow: hidden;
}

.plan-details {
  background: var(--bg-card);
  padding: 28px 32px;
  margin-bottom: 24px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 24px 36px;
  align-items: center;
}

.plan-specs {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 24px;
  font-size: 0.86rem;
}

.plan-specs li {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
}

.plan-specs li::before {
  content: "—";
  color: var(--text-secondary);
}

.plan-action-box {
  text-align: right;
}

.plan-note {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.plan-cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 28px;
  border-radius: 999px;
  background: var(--accent-black);
  color: var(--accent-white);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  transition: opacity 0.25s ease, transform 0.25s var(--ease-editorial);
}

.plan-cta:hover {
  opacity: 0.88;
  transform: translateY(-1px);
}

@media (max-width: 768px) {
  .plan-title-group {
    flex-wrap: wrap;
    gap: 8px;
  }

  .plan-details {
    grid-template-columns: 1fr;
    padding: 22px 20px;
  }

  .plan-specs {
    grid-template-columns: 1fr;
  }

  .plan-action-box {
    text-align: left;
  }
}

/* ==========================================================================
   Section 4B: Core Advantages (Editorial Staggered Grid)
   ========================================================================== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.adv-card {
  background: var(--bg-card);
  padding: 32px;
  border: 1px solid var(--border-subtle);
  transition: transform 0.35s var(--ease-editorial), border-color 0.35s ease;
}

.adv-card:nth-child(even) {
  transform: translateY(20px);
}

.adv-card:hover {
  border-color: var(--border-hairline);
}

.adv-num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
  margin-bottom: 18px;
  display: block;
}

.adv-title {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 500;
  margin-bottom: 12px;
}

.adv-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

@media (max-width: 768px) {
  .advantages-grid {
    grid-template-columns: 1fr;
  }

  .adv-card:nth-child(even) {
    transform: none;
  }
}

/* ==========================================================================
   Section 5A: FAQ Accordion
   ========================================================================== */
.faq-list {
  border-top: 1px solid var(--border-hairline);
}

.faq-item {
  border-bottom: 1px solid var(--border-hairline);
}

.faq-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 4px;
  text-align: left;
  font-size: 0.98rem;
  font-weight: 500;
}

.faq-trigger span.faq-plus {
  font-family: var(--font-mono);
  color: var(--text-secondary);
  transition: transform 0.3s var(--ease-editorial);
}

.faq-item.is-open .faq-plus {
  transform: rotate(45deg);
  color: var(--text-primary);
}

.faq-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.35s var(--ease-editorial);
}

.faq-item.is-open .faq-panel {
  grid-template-rows: 1fr;
}

.faq-answer {
  overflow: hidden;
}

.faq-answer p {
  padding: 0 4px 22px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.85;
}

/* ==========================================================================
   Section 5B: Knowledge Base & Tutorials Grid (10 Dedicated SEO Articles)
   ========================================================================== */
.kb-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 28px;
}

.kb-filter-btn {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--border-hairline);
  color: var(--text-secondary);
  transition: all 0.25s ease;
}

.kb-filter-btn.is-active,
.kb-filter-btn:hover {
  background: var(--accent-black);
  color: var(--accent-white);
  border-color: var(--accent-black);
}

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

.kb-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--bg-card);
  padding: 26px 28px;
  border: 1px solid var(--border-subtle);
  transition: background 0.25s ease, transform 0.3s var(--ease-editorial);
}

.kb-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.kb-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-secondary);
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}

.kb-title {
  font-family: var(--font-display);
  font-size: 1.28rem;
  font-weight: 500;
  line-height: 1.38;
  margin-bottom: 10px;
}

.kb-excerpt {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 18px;
}

.kb-readmore {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

@media (max-width: 768px) {
  .kb-grid {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   Section 6: User Reviews (Editorial Testimonials)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.review-card {
  background: var(--bg-card);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
}

.review-quote {
  font-size: 0.88rem;
  line-height: 1.85;
  color: var(--text-primary);
}

.review-author {
  border-top: 1px solid var(--border-subtle);
  padding-top: 14px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
}

.review-name {
  font-size: 0.82rem;
  font-weight: 500;
}

.review-role {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-secondary);
}

@media (max-width: 960px) {
  .reviews-grid {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   Footer (Zero sitemap.xml / robots.txt references as requested)
   ========================================================================== */
.site-footer {
  border-top: 1px solid var(--border-hairline);
  padding-block: 56px 72px;
  margin-top: 40px;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-start;
  gap: 32px;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 1.4rem;
  letter-spacing: 0.14em;
  margin-bottom: 10px;
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-secondary);
  max-width: 340px;
  line-height: 1.7;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 28px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

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

/* ==========================================================================
   Article Detail Pages
   ========================================================================== */
.article-header {
  padding-block: 64px 36px;
  border-bottom: 1px solid var(--border-hairline);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

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

.article-title {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 3.2vw, 3rem);
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: 0.02em;
  margin-bottom: 20px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
}

.article-body {
  padding-block: 48px 56px;
  font-size: 0.98rem;
  line-height: 1.95;
  color: var(--text-primary);
}

.article-body h2 {
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 500;
  margin: 40px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
}

.article-body h3 {
  font-size: 1.08rem;
  font-weight: 600;
  margin: 26px 0 10px;
}

.article-body p {
  margin-bottom: 18px;
  color: #1f1f1f;
}

.article-body ul,
.article-body ol {
  margin: 14px 0 22px 22px;
  color: #1f1f1f;
}

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

.article-callout {
  background: var(--bg-card);
  padding: 24px 28px;
  border-left: 2px solid var(--text-primary);
  margin: 32px 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.article-cta-box {
  background: var(--bg-card);
  padding: 36px 32px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 48px;
}

.related-articles {
  border-top: 1px solid var(--border-hairline);
  padding-top: 40px;
  margin-bottom: 56px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 20px;
}

@media (max-width: 640px) {
  .related-grid {
    grid-template-columns: 1fr;
  }
}