/* ==========================================================================
   GLADOS CONCRETE INDUSTRIAL TECHNOLOGY DESIGN SYSTEM
   Theme: Raw Concrete + Architectural Structure + Brutalist Infrastructure
   ========================================================================== */

:root {
  /* Concrete Palette */
  --bg-concrete: #D9D8D3;
  --bg-concrete-light: #EFEDE8;
  --bg-concrete-mid: #E2E0DB;
  --bg-concrete-slate: #CBCBC6;
  --bg-concrete-dark: #8C8D89;
  
  /* Industrial Solids */
  --charcoal-900: #171817;
  --charcoal-800: #202120;
  --text-primary: #171817;
  --text-body: #3D3F3C;
  --text-muted: #6C7376;
  --industrial-metal: #A6AAAB;
  --steel-gray: #6C7376;
  --steel-border: #4A4D4A;
  --border-concrete: #BCBCB5;
  --border-light: #DDDCD6;
  
  /* Signal Accent */
  --signal-red: #E63B2E;
  --signal-red-hover: #D12F22;
  --signal-yellow: #F2B84B;
  --white-surface: #F6F5F1;

  /* Typography */
  --font-mono: ui-monospace, "SF Mono", "Roboto Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --font-display: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;

  /* Spatial & Grid Constraints */
  --max-width: 1320px;
  --container-pad: clamp(1rem, 3vw, 2.5rem);
  --border-radius: 0px;
  --border-radius-sm: 2px;
  --border-radius-md: 4px;
  
  /* Hard Industrial Shadows (strictly NO soft SaaS blur) */
  --shadow-hard-sm: 2px 2px 0 var(--charcoal-900);
  --shadow-hard-md: 4px 4px 0 var(--charcoal-900);
  --shadow-hard-lg: 8px 8px 0 var(--charcoal-900);
  --shadow-red-md: 4px 4px 0 var(--signal-red);
}

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

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

body {
  background-color: var(--bg-concrete);
  color: var(--text-body);
  font-family: var(--font-display);
  line-height: 1.6;
  font-weight: 400;
  overflow-x: hidden;
  position: relative;
  /* Raw Concrete grain simulation via micro grid */
  background-image: 
    radial-gradient(var(--border-concrete) 1px, transparent 1px),
    linear-gradient(to right, rgba(0,0,0,0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0,0,0,0.02) 1px, transparent 1px);
  background-size: 24px 24px, 48px 48px, 48px 48px;
}

/* Architectural Top Reference Ruler Bar */
.datum-bar {
  background: var(--charcoal-900);
  color: var(--industrial-metal);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  padding: 5px var(--container-pad);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--charcoal-800);
  text-transform: uppercase;
}
.datum-bar-left, .datum-bar-right {
  display: flex;
  gap: 1.5rem;
}
.datum-tag {
  color: var(--signal-red);
  font-weight: 700;
}

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

/* Header: Architectural Grid Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 999;
  background: var(--bg-concrete-light);
  border-bottom: 2px solid var(--charcoal-900);
  box-shadow: 0 4px 0 rgba(23, 24, 23, 0.08);
}

.header-inner {
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  min-height: 68px;
  position: relative;
}

.header-brand-block {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-right: 20px;
  border-right: 1px solid var(--border-concrete);
}

.brand-title {
  font-size: 1.75rem;
  font-weight: 900;
  color: var(--charcoal-900);
  text-decoration: none;
  letter-spacing: -0.04em;
  line-height: 1;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.brand-dot {
  width: 7px;
  height: 7px;
  background: var(--signal-red);
  display: inline-block;
}

.brand-meta {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--steel-gray);
  line-height: 1.2;
  border-left: 2px solid var(--charcoal-900);
  padding-left: 8px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.nav-desktop {
  display: flex;
  align-items: center;
  flex: 1;
  padding: 0 1.25rem;
  gap: 1rem;
}

.nav-link {
  color: var(--charcoal-900);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 8px 4px;
  position: relative;
  transition: color 0.15s ease;
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--signal-red);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--signal-red);
  transition: width 0.2s ease;
}

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

.header-action-block {
  display: flex;
  align-items: center;
  padding-left: 1.25rem;
  border-left: 1px solid var(--border-concrete);
}

/* Mobile Nav Toggle */
.mobile-toggle {
  display: none;
  background: none;
  border: 1px solid var(--charcoal-900);
  padding: 8px 10px;
  cursor: pointer;
  align-self: center;
}
.mobile-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--charcoal-900);
  margin: 4px 0;
}

/* Mobile Nav Panel (Hidden by default on desktop) */
.mobile-nav-panel {
  display: none;
}

/* Button & Action System */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  text-decoration: none;
  border-radius: var(--border-radius-sm);
  transition: transform 0.1s ease, box-shadow 0.1s ease, background-color 0.15s ease;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  white-space: nowrap;
}

.btn-signal {
  background: var(--signal-red);
  color: var(--white-surface);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-sm);
}

.btn-signal:hover {
  background: var(--signal-red-hover);
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-hard-md);
}

.btn-secondary {
  background: transparent;
  color: var(--charcoal-900);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-sm);
}

.btn-secondary:hover {
  background: var(--charcoal-900);
  color: var(--white-surface);
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-hard-md);
}

.btn-sm {
  padding: 0.45rem 0.9rem;
  font-size: 0.82rem;
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.05rem;
}

/* Section Common System */
.section {
  padding: clamp(3.5rem, 7vw, 6.5rem) 0;
  position: relative;
  border-bottom: 2px solid var(--charcoal-900);
}

.section-head {
  margin-bottom: clamp(2rem, 4vw, 3.5rem);
  border-left: 4px solid var(--charcoal-900);
  padding-left: 1.25rem;
  position: relative;
}

.section-head.has-signal {
  border-left-color: var(--signal-red);
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--signal-red);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 700;
  margin-bottom: 4px;
  display: block;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 800;
  color: var(--charcoal-900);
  letter-spacing: -0.03em;
  line-height: 1.1;
  text-transform: uppercase;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-body);
  max-width: 680px;
  margin-top: 0.75rem;
  line-height: 1.6;
}

/* Hero: Architectural Mass Hero */
.hero-section {
  background-color: var(--bg-concrete-mid);
  padding-top: clamp(2.5rem, 5vw, 4.5rem);
  padding-bottom: clamp(3.5rem, 6vw, 5.5rem);
  border-bottom: 2px solid var(--charcoal-900);
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: clamp(2rem, 4vw, 4rem);
  align-items: center;
}

.hero-label-box {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--charcoal-900);
  color: var(--white-surface);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 4px 10px;
  margin-bottom: 1.5rem;
  border-radius: var(--border-radius-sm);
  letter-spacing: 0.08em;
}

.hero-label-box span {
  color: var(--signal-red);
  font-weight: 700;
}

.hero-h1-brand {
  font-size: clamp(4rem, 9vw, 9rem);
  font-weight: 800;
  letter-spacing: -0.05em;
  line-height: 0.92;
  color: var(--charcoal-900);
  margin-bottom: 0.5rem;
  text-transform: uppercase;
}

.hero-h1-brand span {
  color: var(--signal-red);
}

.hero-subheading {
  font-size: clamp(1.4rem, 2.5vw, 2.2rem);
  font-weight: 700;
  color: var(--charcoal-900);
  line-height: 1.25;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}

.hero-lead-text {
  font-size: 1.05rem;
  color: var(--text-body);
  line-height: 1.65;
  max-width: 580px;
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 2.5rem;
}

.hero-specs-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  border-top: 1px solid var(--border-concrete);
  padding-top: 1.5rem;
  max-width: 580px;
}

.spec-cell {
  font-family: var(--font-mono);
}
.spec-cell-num {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--charcoal-900);
  display: block;
}
.spec-cell-lbl {
  font-size: 0.72rem;
  color: var(--steel-gray);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Hero Structural Network Object */
.structural-network-object {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-lg);
  padding: 1.75rem;
  position: relative;
}

.s-obj-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 2px solid var(--charcoal-900);
  padding-bottom: 0.75rem;
  margin-bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.s-obj-title {
  font-weight: 700;
  color: var(--charcoal-900);
}

.s-obj-status {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--charcoal-900);
}

.s-obj-dot {
  width: 8px;
  height: 8px;
  background: var(--signal-red);
  border-radius: 50%;
  animation: pulse-node 2s infinite ease-in-out;
}

@keyframes pulse-node {
  0% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.3); opacity: 0.7; }
  100% { transform: scale(1); opacity: 1; }
}

.s-obj-core-block {
  background: var(--charcoal-900);
  color: var(--white-surface);
  padding: 1.5rem;
  border-left: 4px solid var(--signal-red);
  margin-bottom: 1.25rem;
}

.s-obj-core-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--industrial-metal);
  letter-spacing: 0.1em;
}

.s-obj-core-name {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 4px 0 8px;
}

.s-obj-core-metric {
  display: flex;
  gap: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--border-light);
}

.s-obj-modules-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-bottom: 1.25rem;
}

.s-module-item {
  background: var(--bg-concrete-slate);
  border: 1px solid var(--charcoal-900);
  padding: 10px 12px;
  font-family: var(--font-mono);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.s-mod-code {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--charcoal-900);
}

.s-mod-val {
  font-size: 0.72rem;
  color: var(--signal-red);
  font-weight: 700;
}

.s-obj-footer {
  border-top: 1px dashed var(--charcoal-900);
  padding-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--steel-gray);
  display: flex;
  justify-content: space-between;
}

/* ==========================================================================
   MODULES SECTION: Asymmetric Architectural Grid
   ========================================================================== */
.modules-blueprint-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  grid-template-rows: auto auto;
  gap: 16px;
}

.mod-block {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  padding: clamp(1.5rem, 3vw, 2.25rem);
  box-shadow: var(--shadow-hard-md);
  position: relative;
}

.mod-block-span-2 {
  grid-column: 1 / -1;
}

.mod-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 2px solid var(--charcoal-900);
  padding-bottom: 0.75rem;
  margin-bottom: 1.25rem;
}

.mod-id {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--signal-red);
  font-weight: 700;
  letter-spacing: 0.08em;
}

.mod-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--charcoal-900);
  letter-spacing: -0.02em;
}

.mod-desc {
  font-size: 0.95rem;
  color: var(--text-body);
  margin-bottom: 1.25rem;
  line-height: 1.55;
}

/* Global Network Elements in Module 01 */
.net-nodes-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.net-node-chip {
  background: var(--bg-concrete);
  border: 1px solid var(--charcoal-900);
  padding: 10px;
  font-family: var(--font-mono);
  text-align: center;
}

.net-node-chip.active {
  border-top: 3px solid var(--signal-red);
  background: var(--white-surface);
}

.net-node-code {
  font-size: 0.88rem;
  font-weight: 800;
  color: var(--charcoal-900);
  display: block;
}

.net-node-name {
  font-size: 0.7rem;
  color: var(--steel-gray);
}

/* Multi Device Grid in Module 02 */
.device-unit-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.device-chip {
  background: var(--white-surface);
  border: 1px solid var(--charcoal-900);
  padding: 10px 8px;
  text-align: center;
  font-family: var(--font-mono);
}

.device-chip-id {
  font-size: 0.68rem;
  color: var(--signal-red);
  font-weight: 700;
}

.device-chip-name {
  font-size: 0.85rem;
  font-weight: 800;
  color: var(--charcoal-900);
}

/* Big Number Badge in Module 03 / 04 */
.big-count-badge {
  font-size: clamp(3rem, 5vw, 4.5rem);
  font-weight: 900;
  color: var(--charcoal-900);
  line-height: 1;
  letter-spacing: -0.05em;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.big-count-badge span {
  font-size: 1rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--steel-gray);
  letter-spacing: 0;
}

.service-pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.service-pill {
  background: var(--bg-concrete);
  border: 1px solid var(--charcoal-900);
  padding: 4px 10px;
  font-size: 0.82rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--charcoal-900);
}

/* ==========================================================================
   GLOBAL INFRASTRUCTURE: Regional Structure Blocks
   ========================================================================== */
.region-blocks-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 2.5rem;
}

.region-box {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.region-box-header {
  border-bottom: 2px solid var(--charcoal-900);
  padding-bottom: 0.75rem;
  margin-bottom: 1rem;
}

.region-code {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--signal-red);
  font-weight: 700;
}

.region-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--charcoal-900);
}

.region-node-list {
  list-style: none;
}

.region-node-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid var(--border-concrete);
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.region-node-item:last-child {
  border-bottom: none;
}

.node-idx {
  color: var(--steel-gray);
  margin-right: 6px;
}
.node-label {
  font-weight: 700;
  color: var(--charcoal-900);
}
.node-stat {
  color: var(--signal-red);
  font-size: 0.72rem;
  font-weight: 700;
}

/* Connection Structure Path */
.connection-path-box {
  background: var(--charcoal-900);
  color: var(--white-surface);
  border: 2px solid var(--charcoal-900);
  padding: 1.75rem;
}

.conn-path-title {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--industrial-metal);
  letter-spacing: 0.1em;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
}

.conn-steps-flex {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.conn-step-node {
  background: var(--charcoal-800);
  border: 1px solid var(--steel-border);
  padding: 12px 16px;
  font-family: var(--font-mono);
  min-width: 170px;
  text-align: center;
}

.conn-step-label {
  font-size: 0.68rem;
  color: var(--industrial-metal);
  display: block;
}

.conn-step-name {
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--white-surface);
}

.conn-arrow {
  color: var(--signal-red);
  font-weight: 900;
  font-size: 1.25rem;
}

/* ==========================================================================
   DEVICE STRUCTURE
   ========================================================================== */
.device-wall-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.device-wall-card {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-md);
  padding: 1.75rem 1.5rem;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 240px;
}

.dwall-num {
  font-size: 2.25rem;
  font-weight: 900;
  line-height: 1;
  color: var(--signal-red);
  font-family: var(--font-mono);
  margin-bottom: 0.5rem;
}

.dwall-name {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--charcoal-900);
  margin-bottom: 0.75rem;
}

.dwall-desc {
  font-size: 0.88rem;
  color: var(--text-body);
  line-height: 1.55;
  margin-bottom: 1.25rem;
}

.dwall-footer {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--steel-gray);
  border-top: 1px solid var(--border-concrete);
  padding-top: 8px;
  display: flex;
  justify-content: space-between;
}

/* ==========================================================================
   DUAL INDUSTRIAL SYSTEM (AI + STREAMING)
   ========================================================================== */
.dual-system-box {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-lg);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: stretch;
}

.dual-column {
  padding: clamp(1.75rem, 4vw, 3rem);
}

.steel-divider {
  width: 2px;
  background: var(--charcoal-900);
  position: relative;
}

.steel-divider::before {
  content: "SYS // DIV";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) rotate(-90deg);
  background: var(--charcoal-900);
  color: var(--white-surface);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  padding: 4px 8px;
  white-space: nowrap;
  letter-spacing: 0.1em;
}

.dual-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 2px solid var(--charcoal-900);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

.dual-title-group h3 {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--charcoal-900);
  letter-spacing: -0.02em;
}

.dual-count {
  font-size: 3.25rem;
  font-weight: 900;
  color: var(--charcoal-900);
  line-height: 1;
  letter-spacing: -0.05em;
}

.catalog-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.catalog-item {
  background: var(--bg-concrete);
  border: 1px solid var(--charcoal-900);
  padding: 12px 14px;
  font-family: var(--font-mono);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.cat-id {
  font-size: 0.72rem;
  color: var(--signal-red);
  font-weight: 700;
}

.cat-name {
  font-size: 0.92rem;
  font-weight: 800;
  color: var(--charcoal-900);
}

/* ==========================================================================
   ARCHITECTURAL PRICING STRUCTURE
   ========================================================================== */
.pricing-structure-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  align-items: end; /* Creates modular mass height difference */
}

.pricing-block {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-md);
  padding: 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  transition: transform 0.15s ease;
}

.pricing-block:hover {
  transform: translateY(-4px);
}

/* Plan Mass Hierarchy */
.pricing-plan-01 { min-height: 480px; }
.pricing-plan-02 { min-height: 520px; }
.pricing-plan-03 {
  min-height: 570px;
  border-left: 6px solid var(--signal-red);
  box-shadow: var(--shadow-hard-lg);
  background: var(--white-surface);
}
.pricing-plan-04 { min-height: 540px; }

.plan-badge-recommended {
  position: absolute;
  top: -14px;
  right: 14px;
  background: var(--signal-red);
  color: var(--white-surface);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  padding: 4px 10px;
  letter-spacing: 0.08em;
  border: 1px solid var(--charcoal-900);
}

.plan-header {
  border-bottom: 2px solid var(--charcoal-900);
  padding-bottom: 1.25rem;
  margin-bottom: 1.5rem;
}

.plan-id {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--signal-red);
  font-weight: 700;
  letter-spacing: 0.08em;
}

.plan-name {
  font-size: 1.65rem;
  font-weight: 900;
  color: var(--charcoal-900);
  letter-spacing: -0.02em;
  text-transform: uppercase;
}

.plan-subtitle {
  font-size: 0.88rem;
  color: var(--steel-gray);
  margin-top: 2px;
}

.plan-price-block {
  margin-bottom: 1.25rem;
}

.plan-price-num {
  font-size: clamp(2.4rem, 4vw, 3.4rem);
  font-weight: 900;
  color: var(--charcoal-900);
  line-height: 1;
  letter-spacing: -0.04em;
}

.plan-price-cycle {
  font-size: 0.9rem;
  color: var(--steel-gray);
  font-weight: 600;
  font-family: var(--font-mono);
}

.plan-bandwidth-banner {
  background: var(--bg-concrete);
  border: 1px solid var(--charcoal-900);
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--charcoal-900);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 1.5rem;
}

.plan-features-list {
  list-style: none;
  margin-bottom: 2rem;
  flex: 1;
}

.plan-feature-item {
  padding: 8px 0;
  border-bottom: 1px dashed var(--border-concrete);
  font-size: 0.88rem;
  color: var(--text-body);
  display: flex;
  align-items: center;
  gap: 8px;
}

.plan-feature-item::before {
  content: "■";
  color: var(--signal-red);
  font-size: 0.65rem;
}

.plan-cta-wrap {
  margin-top: auto;
}
.plan-cta-wrap .btn {
  width: 100%;
}

/* ==========================================================================
   INFRASTRUCTURE JOURNAL (SEO Articles Section on Homepage)
   ========================================================================== */
.editorial-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 20px;
}

.featured-article-card {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  border-left: 6px solid var(--signal-red);
  box-shadow: var(--shadow-hard-md);
  padding: clamp(1.75rem, 3.5vw, 2.5rem);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.journal-doc-id {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--signal-red);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}

.journal-doc-title {
  font-size: clamp(1.5rem, 2.8vw, 2.2rem);
  font-weight: 800;
  color: var(--charcoal-900);
  line-height: 1.25;
  margin-bottom: 1rem;
}

.journal-doc-title a {
  color: inherit;
  text-decoration: none;
}
.journal-doc-title a:hover {
  color: var(--signal-red);
}

.journal-doc-summary {
  font-size: 0.95rem;
  color: var(--text-body);
  line-height: 1.65;
  margin-bottom: 1.5rem;
}

.journal-doc-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--steel-gray);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--charcoal-900);
  padding-top: 1rem;
}

.article-list-stack {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.article-list-row {
  background: var(--bg-concrete-light);
  border: 1px solid var(--charcoal-900);
  box-shadow: 2px 2px 0 var(--charcoal-900);
  padding: 14px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  text-decoration: none;
  color: inherit;
  transition: transform 0.1s ease, border-color 0.15s ease;
}

.article-list-row:hover {
  transform: translateX(4px);
  border-left: 4px solid var(--signal-red);
}

.row-left {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.row-code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--signal-red);
  font-weight: 700;
}

.row-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--charcoal-900);
}

.row-meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--steel-gray);
  white-space: nowrap;
}

/* ==========================================================================
   SITE REPORTS (Structure Notes)
   ========================================================================== */
.reports-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.report-card {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-md);
  padding: 1.75rem;
  position: relative;
}

.report-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-concrete);
  padding-bottom: 8px;
  margin-bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
}

.report-id {
  color: var(--signal-red);
  font-weight: 700;
}

.report-tag {
  color: var(--charcoal-900);
  font-weight: 800;
  letter-spacing: 0.05em;
}

.report-quote {
  font-size: 0.95rem;
  color: var(--charcoal-900);
  line-height: 1.65;
  font-weight: 500;
  margin-bottom: 1.25rem;
}

.report-footer {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--steel-gray);
  display: flex;
  align-items: center;
  gap: 6px;
}

.report-footer-dot {
  width: 6px;
  height: 6px;
  background: var(--signal-red);
  display: inline-block;
}

/* ==========================================================================
   SPECIFICATION FAQ (Industrial Spec Accordion)
   ========================================================================== */
.faq-spec-table {
  border: 2px solid var(--charcoal-900);
  background: var(--bg-concrete-light);
  box-shadow: var(--shadow-hard-lg);
}

.faq-item {
  border-bottom: 1px solid var(--charcoal-900);
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  background: transparent;
  border: none;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-display);
  transition: background-color 0.15s ease;
}

.faq-trigger:hover {
  background-color: var(--bg-concrete-slate);
}

.faq-trigger-left {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.faq-spec-id {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--signal-red);
}

.faq-question {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--charcoal-900);
}

.faq-icon {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--charcoal-900);
  transition: transform 0.2s ease;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
  color: var(--signal-red);
}

.faq-content {
  display: none;
  padding: 0 1.5rem 1.5rem 4.5rem;
  color: var(--text-body);
  font-size: 0.95rem;
  line-height: 1.65;
  background: var(--white-surface);
  border-top: 1px dashed var(--border-concrete);
}

.faq-item.active .faq-content {
  display: block;
  padding-top: 1.25rem;
}

.spec-note-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--steel-gray);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 6px;
  display: block;
}

/* ==========================================================================
   FOOTER: Concrete Industrial Technology Dark Floor
   ========================================================================== */
.site-footer {
  background: var(--charcoal-900);
  color: var(--bg-concrete-mid);
  padding: clamp(3.5rem, 6vw, 5.5rem) 0 2rem;
  position: relative;
  border-top: 4px solid var(--signal-red);
}

.footer-watermark {
  font-size: clamp(3.5rem, 11vw, 10rem);
  font-weight: 900;
  color: rgba(255, 255, 255, 0.04);
  line-height: 0.8;
  letter-spacing: -0.05em;
  text-transform: uppercase;
  margin-bottom: 2rem;
  user-select: none;
  pointer-events: none;
}

.footer-main-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: clamp(2rem, 4vw, 3.5rem);
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--steel-border);
}

.footer-brand-title {
  font-size: 1.8rem;
  font-weight: 900;
  color: var(--white-surface);
  letter-spacing: -0.03em;
  margin-bottom: 0.5rem;
}

.footer-brand-tagline {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--industrial-metal);
  line-height: 1.4;
  margin-bottom: 1.25rem;
}

.footer-brand-desc {
  font-size: 0.9rem;
  color: var(--industrial-metal);
  line-height: 1.6;
  max-width: 320px;
}

.footer-col-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--signal-red);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 1.25rem;
  border-left: 2px solid var(--signal-red);
  padding-left: 8px;
}

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

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

.footer-links-list a {
  color: var(--bg-concrete-mid);
  text-decoration: none;
  font-size: 0.88rem;
  transition: color 0.15s ease;
}

.footer-links-list a:hover {
  color: var(--white-surface);
  text-decoration: underline;
}

.footer-related-note {
  margin-top: 1.5rem;
  padding: 1rem;
  background: var(--charcoal-800);
  border: 1px solid var(--steel-border);
  font-size: 0.82rem;
}

.footer-related-note a {
  color: var(--industrial-metal);
  text-decoration: underline;
  margin-right: 14px;
  display: inline-block;
}

.footer-related-note a:hover {
  color: var(--white-surface);
}

.footer-bottom-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 2rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--steel-gray);
  flex-wrap: wrap;
  gap: 12px;
}

.footer-specs-badge {
  display: flex;
  gap: 1.5rem;
}

/* ==========================================================================
   ARTICLE & EDITORIAL STYLING (For SEO Longforms & Standalone Pages)
   ========================================================================== */
.article-header {
  background: var(--bg-concrete-mid);
  padding: clamp(3rem, 6vw, 4.5rem) 0 2.5rem;
  border-bottom: 2px solid var(--charcoal-900);
}

.breadcrumb-nav {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--steel-gray);
  margin-bottom: 1.25rem;
}

.breadcrumb-nav a {
  color: var(--charcoal-900);
  text-decoration: none;
  font-weight: 600;
}

.breadcrumb-nav a:hover {
  color: var(--signal-red);
}

.breadcrumb-sep {
  margin: 0 6px;
  color: var(--signal-red);
}

.article-h1 {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  font-weight: 900;
  color: var(--charcoal-900);
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
}

.article-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--steel-gray);
  border-top: 1px solid var(--border-concrete);
  padding-top: 1rem;
}

.article-body-wrapper {
  padding: clamp(3rem, 5vw, 4.5rem) 0;
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: clamp(2rem, 4vw, 3.5rem);
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-body);
}

.article-content h2 {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--charcoal-900);
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--charcoal-900);
  letter-spacing: -0.02em;
}

.article-content h3 {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--charcoal-900);
  margin: 1.75rem 0 0.75rem;
  border-left: 3px solid var(--signal-red);
  padding-left: 10px;
}

.article-content p {
  margin-bottom: 1.25rem;
}

.article-content ul, .article-content ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

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

.article-content blockquote {
  background: var(--bg-concrete-light);
  border-left: 4px solid var(--charcoal-900);
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--charcoal-900);
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.75rem 0;
  font-size: 0.95rem;
  background: var(--white-surface);
  border: 2px solid var(--charcoal-900);
}

.article-content th, .article-content td {
  border: 1px solid var(--charcoal-900);
  padding: 10px 14px;
  text-align: left;
}

.article-content th {
  background: var(--charcoal-900);
  color: var(--white-surface);
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.article-callout-box {
  background: var(--bg-concrete-slate);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-md);
  padding: 1.5rem;
  margin: 2rem 0;
}

.article-callout-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--signal-red);
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

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

.sidebar-widget {
  background: var(--bg-concrete-light);
  border: 2px solid var(--charcoal-900);
  box-shadow: var(--shadow-hard-md);
  padding: 1.5rem;
}

.sidebar-widget-title {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--charcoal-900);
  border-bottom: 2px solid var(--charcoal-900);
  padding-bottom: 8px;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ==========================================================================
   RESPONSIVE LAYOUT (375px, 390px, 430px, 768px, 1024px, 1440px)
   ========================================================================== */

@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  
  .modules-blueprint-grid {
    grid-template-columns: 1fr;
  }
  
  .region-blocks-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .device-wall-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .dual-system-box {
    grid-template-columns: 1fr;
  }
  .steel-divider {
    height: 2px;
    width: 100%;
  }
  .steel-divider::before {
    transform: translate(-50%, -50%);
  }

  .pricing-structure-grid {
    grid-template-columns: repeat(2, 1fr);
    align-items: stretch;
  }
  .pricing-block {
    min-height: auto;
  }

  .editorial-grid {
    grid-template-columns: 1fr;
  }

  .reports-grid {
    grid-template-columns: 1fr;
  }

  .footer-main-grid {
    grid-template-columns: 1fr 1fr;
  }

  .article-body-wrapper {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .datum-bar {
    display: none;
  }

  .nav-desktop {
    display: none;
  }

  .mobile-toggle {
    display: block;
  }

  /* Mobile Dropdown Nav */
  .mobile-nav-panel {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-concrete-light);
    border-bottom: 2px solid var(--charcoal-900);
    padding: 1rem var(--container-pad);
    flex-direction: column;
    gap: 12px;
    box-shadow: 0 8px 12px rgba(0,0,0,0.15);
  }
  .mobile-nav-panel.open {
    display: flex;
  }

  .hero-specs-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .region-blocks-grid {
    grid-template-columns: 1fr;
  }

  .device-wall-grid {
    grid-template-columns: 1fr;
  }

  .pricing-structure-grid {
    grid-template-columns: 1fr;
  }

  .catalog-list {
    grid-template-columns: 1fr;
  }

  .footer-main-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .net-nodes-bar {
    grid-template-columns: repeat(2, 1fr);
  }

  .device-unit-row {
    grid-template-columns: repeat(2, 1fr);
  }

  .conn-steps-flex {
    flex-direction: column;
  }
  .conn-step-node {
    width: 100%;
  }
  .conn-arrow {
    transform: rotate(90deg);
  }

  .faq-content {
    padding-left: 1.5rem;
  }
}

/* Specific narrow devices: 375px, 390px, 430px */
@media (max-width: 430px) {
  .hero-h1-brand {
    font-size: 3.5rem;
  }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .hero-actions .btn {
    width: 100%;
  }
  .s-obj-modules-grid {
    grid-template-columns: 1fr;
  }
}