/* ==========================================================================
   杨帆云 - 夜航信号系统 样式表
   Design Edition 3: Night Voyage Signal System
   ========================================================================== */

:root {
  --bg: #11181B;
  --bg-deep: #0D1416;
  --surface: #1A2428;
  --surface-alt: #202D31;
  --surface-light: #263438;
  --text: #F1F3F0;
  --body: #BBC3BF;
  --muted: #87918D;
  --signal-dark: #467C7A;
  --signal: #5B9B98;
  --signal-soft: #86BBB5;
  --mist: #758F79;
  --mist-soft: #98A995;
  --warm: #C7A15D;
  --warm-soft: #E0C58C;
  --error: #8E5A55;
  --error-soft: #AD7771;
  --border: #314044;
  --border-light: #43565A;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  
  --radius: 3px;
  --radius-sm: 2px;
  --header-height: 68px;
  --max-width: 1320px;
  --content-width: 820px;
}

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

html {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.8;
  color: var(--body);
  background-color: var(--bg);
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-color: var(--bg);
}

::selection {
  background: var(--signal-dark);
  color: var(--text);
}

:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
}

a:hover {
  color: var(--signal-soft);
}

img, svg {
  display: block;
  max-width: 100%;
}

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

/* Typography Defaults */
h1, h2, h3, h4, h5, h6 {
  color: var(--text);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(2rem, 4.5vw, 3.8rem);
  line-height: 1.25;
}

h2 {
  font-size: clamp(1.6rem, 2.8vw, 2.4rem);
  line-height: 1.3;
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.6rem);
}

p {
  font-size: 1.0625rem; /* ~17px */
  line-height: 1.85;
  color: var(--body);
  margin-bottom: 1.25rem;
}

ul, ol {
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
}

li {
  margin-bottom: 0.5rem;
  line-height: 1.75;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 0.15em 0.4em;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--signal-soft);
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.container-narrow {
  width: 100%;
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Signal Indicator Atoms */
.signal-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--signal);
  box-shadow: 0 0 18px rgba(91, 155, 152, 0.2);
  vertical-align: middle;
  margin-right: 8px;
}

.signal-dot.warm {
  background: var(--warm);
  box-shadow: 0 0 18px rgba(199, 161, 93, 0.2);
}

.signal-dot.error {
  background: var(--error);
  box-shadow: 0 0 18px rgba(142, 90, 85, 0.2);
}

.signal-bar-accent {
  display: inline-block;
  height: 2px;
  background: var(--signal);
  vertical-align: middle;
}

.tag {
  display: inline-flex;
  align-items: center;
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  background: var(--surface-alt);
  border: 1px solid var(--border);
  color: var(--signal-soft);
  letter-spacing: 0.02em;
}

.tag.warm {
  color: var(--warm-soft);
  border-color: rgba(199, 161, 93, 0.35);
  background: rgba(199, 161, 93, 0.08);
}

.tag.mist {
  color: var(--mist-soft);
  border-color: rgba(117, 143, 121, 0.35);
  background: rgba(117, 143, 121, 0.08);
}

.tag.error {
  color: var(--error-soft);
  border-color: rgba(142, 90, 85, 0.4);
  background: rgba(142, 90, 85, 0.1);
}

/* Buttons and Links */
.btn-signal {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9375rem;
  font-weight: 500;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius);
  background: var(--surface-alt);
  border: 1px solid var(--border-light);
  color: var(--text);
  transition: all 0.2s ease;
}

.btn-signal:hover {
  background: var(--surface-light);
  border-color: var(--signal);
  color: var(--text);
}

.btn-signal:hover .arrow {
  transform: translateX(3px);
}

.btn-signal-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius);
  background: var(--signal-dark);
  border: 1px solid var(--signal);
  color: #FFFFFF;
  transition: all 0.2s ease;
}

.btn-signal-primary:hover {
  background: var(--signal);
  color: #FFFFFF;
  box-shadow: 0 0 18px rgba(91, 155, 152, 0.15);
}

.btn-signal-primary:hover .arrow {
  transform: translateX(3px);
}

.arrow {
  display: inline-block;
  transition: transform 0.2s ease;
}

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(17, 24, 27, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  gap: 1.5rem;
}

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  flex-shrink: 0;
}

.logo-symbol {
  width: 36px;
  height: 28px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
}

.logo-line {
  height: 2px;
  background: var(--signal);
  border-radius: 1px;
}

.logo-line.l1 { width: 16px; }
.logo-line.l2 { width: 26px; }
.logo-line.l3 { 
  width: 10px; 
  display: flex;
  gap: 3px;
  background: none;
}
.logo-line.l3 span:first-child {
  display: block;
  width: 8px;
  height: 2px;
  background: var(--signal);
}
.logo-line.l3 span.dot {
  display: block;
  width: 3px;
  height: 2px;
  background: var(--warm);
}

.logo-brand {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.05em;
}

.logo-sub {
  font-size: 0.75rem;
  color: var(--muted);
  margin-left: 2px;
  font-weight: 400;
}

/* Nav Links */
.nav-desktop {
  display: flex;
  align-items: center;
  gap: 1.1rem;
  flex-wrap: nowrap;
}

.nav-link {
  font-size: 0.875rem;
  color: var(--body);
  position: relative;
  white-space: nowrap;
  padding: 0.35rem 0.2rem;
  transition: color 0.2s ease;
}

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

.nav-link.active {
  color: var(--signal-soft);
}

.nav-link.active::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 2px;
  background: var(--signal);
}

.header-cta {
  flex-shrink: 0;
}

.mobile-menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--border);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.875rem;
}

.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-deep);
  border-top: 1px solid var(--border);
  padding: 1.5rem;
  overflow-y: auto;
  z-index: 99;
}

.mobile-nav-drawer.is-open {
  display: block;
}

.mobile-nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.mobile-nav-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 0.95rem;
}

/* ==========================================================================
   HERO: 夜航信号剧场 (Night Voyage Signal Theater)
   ========================================================================== */
.hero-theater {
  position: relative;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg-deep) 0%, var(--bg) 100%);
  padding: 2.5rem 0 3.5rem;
  overflow: hidden;
}

.hero-theater-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Horizontal Signal Curtains */
.theater-stage {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 3rem;
}

.theater-curtain {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  transition: transform 0.3s ease, border-color 0.3s ease, opacity 0.3s ease;
}

.theater-curtain:hover {
  border-color: var(--border-light);
  transform: translateX(4px);
}

/* Curtain 1: Brand & Master Question */
.curtain-master {
  min-height: 180px;
  background: radial-gradient(circle at 90% 30%, rgba(91, 155, 152, 0.08) 0%, transparent 60%), var(--surface);
  border-left: 3px solid var(--signal);
}

.curtain-master .curtain-left {
  max-width: 65%;
}

.curtain-tag-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.curtain-master-q {
  font-size: clamp(1.8rem, 3.2vw, 2.7rem);
  color: var(--text);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 0.5rem;
}

.curtain-slogans {
  font-size: 1.05rem;
  color: var(--signal-soft);
  line-height: 1.6;
}

.curtain-master .curtain-right {
  text-align: right;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.5rem;
}

.curtain-huge-num {
  font-size: 4rem;
  font-weight: 800;
  color: rgba(91, 155, 152, 0.2);
  line-height: 1;
  font-family: var(--font-mono);
}

/* Curtain 2: Nodes overview */
.curtain-nodes {
  min-height: 110px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  border-left: 3px solid var(--border-light);
}

.curtain-half {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0;
}

.curtain-half-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  color: var(--text);
  font-size: 1.15rem;
  font-weight: 600;
}

.curtain-half-link:hover {
  color: var(--signal);
}

.curtain-half-divider {
  width: 1px;
  height: 60%;
  background: var(--border);
}

/* Curtain 3: Specific tool blocks */
.curtain-tools {
  min-height: 140px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.tool-entry-link {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0.5rem 0.75rem;
  border-left: 1px solid var(--border);
}

.tool-entry-link:first-child {
  border-left: none;
}

.tool-entry-link .entry-title {
  color: var(--text);
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.tool-entry-link .entry-hint {
  font-size: 0.875rem;
  color: var(--muted);
}

.tool-entry-link:hover .entry-title {
  color: var(--signal-soft);
}

/* Curtain 4: Devices & Media */
.curtain-devices {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  background: var(--surface-alt);
}

/* Hero Bottom Narrative */
.hero-bottom-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 2.5rem;
  align-items: start;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.hero-main-h1 {
  font-size: clamp(1.8rem, 3.2vw, 2.6rem);
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
  margin-bottom: 1.25rem;
}

.hero-desc {
  font-size: 1.1rem;
  line-height: 1.85;
  color: var(--body);
  margin-bottom: 1.75rem;
}

.hero-action-row {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.hero-quick-list {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.hero-quick-list h4 {
  font-size: 0.9375rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.quick-links-stack {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.quick-links-stack a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.9375rem;
  color: var(--text);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  background: var(--surface-alt);
  border: 1px solid transparent;
  transition: all 0.2s ease;
}

.quick-links-stack a:hover {
  border-color: var(--border-light);
  color: var(--signal-soft);
  transform: translateX(3px);
}

/* ==========================================================================
   HOMEPAGE RHYTHMIC SECTIONS (Alternating Widths & Signals)
   ========================================================================== */
.section-diagnostic {
  position: relative;
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--border);
}

.section-diagnostic.bg-alt {
  background-color: var(--surface);
}

.section-diagnostic.bg-deep {
  background-color: var(--bg-deep);
}

/* Section Header Structure */
.section-header-block {
  margin-bottom: 2.5rem;
}

.section-indicator {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.section-num {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--signal);
  font-weight: 700;
}

.section-title-label {
  font-size: 0.875rem;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.section-h2 {
  font-size: clamp(1.5rem, 2.5vw, 2.2rem);
  color: var(--text);
  margin-bottom: 1rem;
  line-height: 1.35;
}

.section-answer-direct {
  font-size: 1.125rem;
  line-height: 1.85;
  color: var(--text);
  background: var(--surface-alt);
  border-left: 3px solid var(--signal);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin-bottom: 2rem;
}

/* 01: All Nodes Timeout (100% wide curtain) */
.sequence-bar-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 12px;
  margin-top: 1.5rem;
}

.sequence-step-card {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1rem;
  display: flex;
  flex-direction: column;
  position: relative;
}

.sequence-step-card .step-order {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--signal);
  margin-bottom: 0.5rem;
}

.sequence-step-card .step-title {
  color: var(--text);
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.sequence-step-card .step-desc {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.6;
  margin: 0;
}

/* 02: Partial Nodes Timeout (Offset Right 75%) */
.width-75-right {
  width: 100%;
  max-width: 1080px;
  margin-left: auto;
  margin-right: 0;
}

.parallel-curtains {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 1.5rem;
}

.curtain-row {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.curtain-row.status-normal {
  border-left: 4px solid var(--mist);
}

.curtain-row.status-abnormal {
  border-left: 4px solid var(--warm);
}

.curtain-col-main h4 {
  font-size: 1.2rem;
  color: var(--text);
  margin-bottom: 0.35rem;
}

.curtain-col-main p {
  font-size: 0.95rem;
  color: var(--body);
  margin: 0;
}

.curtain-col-action {
  flex-shrink: 0;
  text-align: right;
}

/* 03: Connected But Web Fails (Offset Left 90%) */
.width-90-left {
  width: 100%;
  max-width: 1180px;
  margin-left: 0;
  margin-right: auto;
}

.break-diagram-screen {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.25rem 2rem;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 2rem;
  margin-top: 1.5rem;
}

.break-node {
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.break-node h4 {
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.break-node p {
  font-size: 0.9375rem;
  margin: 0;
  color: var(--muted);
}

.break-divider {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.break-line-interrupted {
  width: 120px;
  height: 2px;
  background: repeating-linear-gradient(90deg, var(--signal) 0, var(--signal) 8px, transparent 8px, transparent 14px);
}

.break-symbol {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--warm);
}

.checkpoints-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}

.checkpoint-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.checkpoint-item h5 {
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 0.35rem;
}

.checkpoint-item p {
  font-size: 0.875rem;
  color: var(--muted);
  margin: 0;
}

/* 04: Slow Node (60% width) */
.width-60-center {
  width: 100%;
  max-width: 880px;
  margin: 0 auto;
}

.speed-decay-screen {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  margin-top: 1.5rem;
}

.decay-axis {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.decay-label {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
}

.decay-bars {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-grow: 1;
  margin: 0 2rem;
}

.decay-tick {
  height: 14px;
  background: var(--signal);
  border-radius: 1px;
}

.decay-factors-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.factor-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
}

.factor-box strong {
  display: block;
  color: var(--text);
  margin-bottom: 0.25rem;
  font-size: 0.95rem;
}

.factor-box span {
  font-size: 0.85rem;
  color: var(--muted);
}

/* 05 & 06: AI Platforms & Streaming Media */
.ai-problem-screen {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 2rem;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.25rem 2rem;
  margin-top: 1.5rem;
}

.ai-giant-text {
  font-size: 7rem;
  font-weight: 900;
  color: rgba(91, 155, 152, 0.15);
  font-family: var(--font-mono);
  line-height: 0.9;
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-right: 1px solid var(--border);
  padding-right: 1.5rem;
}

.ai-ribbons-stack {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.ai-ribbon {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--signal);
  border-radius: var(--radius-sm);
  padding: 1rem 1.25rem;
}

.ai-ribbon h4 {
  color: var(--text);
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

.ai-ribbon p {
  font-size: 0.875rem;
  color: var(--body);
  margin: 0;
}

.streaming-broadcast-band {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.broadcast-lane {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.75rem;
  display: grid;
  grid-template-columns: 160px 1fr auto;
  align-items: center;
  gap: 1.5rem;
}

.broadcast-platform {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
}

.broadcast-points {
  font-size: 0.925rem;
  color: var(--body);
}

/* 07: Clash & Clash Verge (Full spread client theater) */
.client-theater-spread {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2.5rem;
  margin-top: 1.5rem;
}

.client-left-split {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.client-app-zone h4 {
  font-size: 1.35rem;
  color: var(--text);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.client-issues-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.client-issue-pill {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  color: var(--body);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.client-issue-pill:hover {
  border-color: var(--signal);
  color: var(--text);
}

.client-platform-index {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.platform-index-item h5 {
  color: var(--signal-soft);
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
}

.platform-index-item p {
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0;
}

/* 08: Subscription & Config (3 unequal screens) */
.screens-trio {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1.1fr;
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.screen-card {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.screen-card h4 {
  font-size: 1.2rem;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.screen-card p {
  font-size: 0.925rem;
  color: var(--body);
  margin-bottom: 1.25rem;
}

/* 09: DNS, Proxy & Permissions (3 vertical inserted slender screens) */
.slender-screens-trio {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.slender-screen {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  position: relative;
}

.slender-screen.dns-screen {
  border-top: 3px solid var(--signal);
}

.slender-screen.proxy-screen {
  border-top: 3px solid var(--mist);
}

.slender-screen.perm-screen {
  border-top: 3px solid var(--warm);
}

.slender-screen h4 {
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.slender-screen p {
  font-size: 0.925rem;
  color: var(--body);
  margin-bottom: 1rem;
}

/* 10: Phone vs PC Device Differences (Left ≠ Right) */
.device-diff-theater {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  margin-top: 1.5rem;
}

.device-comparison-grid {
  display: grid;
  grid-template-columns: 1fr 80px 1fr;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.device-pane {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.device-pane h4 {
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.device-pane p {
  font-size: 0.9rem;
  color: var(--muted);
  margin: 0;
}

.not-equal-center {
  font-size: 3rem;
  font-weight: 900;
  color: var(--warm);
  text-align: center;
  font-family: var(--font-mono);
}

.device-reasons-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
}

.reason-card {
  font-size: 0.875rem;
  color: var(--body);
}

.reason-card strong {
  display: block;
  color: var(--text);
  margin-bottom: 0.25rem;
}

/* 11 & 12: When to Switch Node / Region */
.switch-binary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.switch-box {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem 1.5rem;
}

.switch-box.fit {
  border-top: 3px solid var(--signal);
}

.switch-box.unfit {
  border-top: 3px solid var(--error);
}

.switch-box h4 {
  font-size: 1.2rem;
  color: var(--text);
  margin-bottom: 1rem;
}

.switch-box ul {
  margin: 0;
  padding-left: 1.25rem;
}

.switch-box li {
  font-size: 0.9375rem;
  color: var(--body);
  margin-bottom: 0.6rem;
}

/* 13: Route Universal Knowledge HTML Table */
.table-responsive-wrapper {
  width: 100%;
  overflow-x: auto;
  margin-top: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-alt);
}

.signal-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.9375rem;
}

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

.signal-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  color: var(--body);
  vertical-align: top;
  line-height: 1.65;
}

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

.signal-table tr:hover td {
  background: rgba(91, 155, 152, 0.03);
}

.signal-table .cell-name {
  color: var(--text);
  font-weight: 600;
  white-space: nowrap;
}

/* 14: Core Deep Guide Archive Block */
.guide-archive-block {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.75rem 2.25rem;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 2.5rem;
  position: relative;
  border-left: 4px solid var(--signal);
}

.guide-archive-main h3 {
  font-size: 1.6rem;
  color: var(--text);
  margin-bottom: 1rem;
}

.guide-archive-main .conclusion-text {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--body);
  margin-bottom: 1.5rem;
}

.guide-archive-entries {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  justify-content: center;
}

.archive-entry-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.9375rem;
}

.archive-entry-link:hover {
  border-color: var(--signal);
  color: var(--signal-soft);
  transform: translateX(4px);
}

/* ==========================================================================
   15: PRICING - 夜航结论单 (Night Voyage Conclusion Reports)
   ========================================================================== */
.pricing-conclusion-section {
  padding: 5rem 0;
  background: var(--bg-deep);
  border-bottom: 1px solid var(--border);
}

.pricing-premise-note {
  font-size: 1.05rem;
  color: var(--warm-soft);
  background: rgba(199, 161, 93, 0.08);
  border-left: 3px solid var(--warm);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin-bottom: 2.5rem;
}

.conclusion-reports-stack {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.conclusion-report-tier {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 2rem;
  display: grid;
  grid-template-columns: 180px 1.5fr auto 180px;
  align-items: center;
  gap: 2rem;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.conclusion-report-tier:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.conclusion-report-tier.featured {
  border: 1px solid var(--signal);
  background: var(--surface-alt);
  box-shadow: 0 0 24px rgba(91, 155, 152, 0.06);
}

.tier-status h4 {
  font-size: 1.25rem;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.25rem;
}

.tier-status .status-sub {
  font-size: 0.8125rem;
  color: var(--muted);
}

.tier-scenario p {
  font-size: 0.95rem;
  color: var(--body);
  margin: 0;
}

.tier-pricing-signal {
  text-align: right;
}

.tier-price {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text);
  font-family: var(--font-mono);
  line-height: 1.2;
}

.tier-allowance {
  font-size: 0.85rem;
  color: var(--signal-soft);
}

.tier-action {
  text-align: right;
}

/* ==========================================================================
   16: ARTICLES HUB - 夜航问题索引 (Night Voyage Problem Index)
   ========================================================================== */
.articles-hub-section {
  padding: 5rem 0;
  border-bottom: 1px solid var(--border);
}

.problem-clusters-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.problem-cluster {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 1.75rem;
  display: flex;
  flex-direction: column;
}

.cluster-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.75rem;
}

.cluster-giant-keyword {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--text);
  line-height: 1;
}

.cluster-category-label {
  font-size: 0.875rem;
  color: var(--signal);
}

.cluster-article-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.article-row-item {
  display: flex;
  flex-direction: column;
  padding: 0.5rem 0;
  border-bottom: 1px solid rgba(49, 64, 68, 0.4);
}

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

.article-row-item .item-title {
  color: var(--text);
  font-size: 1rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.25rem;
}

.article-row-item .item-verdict {
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.5;
  margin-bottom: 0.4rem;
}

.article-row-item .item-meta {
  font-size: 0.75rem;
  color: var(--signal-dark);
  display: flex;
  gap: 1rem;
}

.article-row-item:hover .item-title {
  color: var(--signal-soft);
}

/* ==========================================================================
   17: FAQ - 问题信号目录 (Interactive Pure HTML Supported)
   ========================================================================== */
.faq-signal-section {
  padding: 5rem 0;
  border-bottom: 1px solid var(--border);
}

.faq-catalog-stack {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 2rem;
}

.faq-item-details {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item-details[open] {
  border-color: var(--border-light);
}

.faq-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.75rem;
  cursor: pointer;
  user-select: none;
  list-style: none;
}

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

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

.faq-idx {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--signal);
  font-weight: 600;
}

.faq-question-text {
  font-size: 1.1rem;
  color: var(--text);
  font-weight: 600;
}

.faq-icon-mark {
  color: var(--signal);
  font-size: 1.25rem;
  transition: transform 0.2s ease;
}

.faq-item-details[open] .faq-icon-mark {
  transform: rotate(45deg);
}

.faq-answer-body {
  padding: 1.25rem 1.75rem 1.5rem;
  border-top: 1px solid var(--border);
  border-left: 2px solid var(--signal);
  background: var(--surface);
  font-size: 1rem;
  line-height: 1.85;
  color: var(--body);
}

.faq-answer-body p {
  margin: 0;
}

/* ==========================================================================
   FOOTER - 夜航问题目录Footer
   ========================================================================== */
.site-footer {
  background: var(--bg-deep);
  border-top: 1px solid var(--border);
  padding: 4.5rem 0 2.5rem;
  position: relative;
  overflow: hidden;
}

.footer-lines-decor {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: repeating-linear-gradient(90deg, var(--signal) 0, var(--signal) 40px, transparent 40px, transparent 80px);
  opacity: 0.05;
}

.footer-columns-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 2.5rem;
  margin-bottom: 3.5rem;
}

.footer-brand-col .footer-desc {
  font-size: 0.9375rem;
  color: var(--muted);
  line-height: 1.75;
  margin-top: 1rem;
  margin-bottom: 1.5rem;
}

.footer-col h5 {
  font-size: 0.9375rem;
  color: var(--text);
  font-weight: 600;
  letter-spacing: 0.04em;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

.footer-links-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links-list a {
  font-size: 0.875rem;
  color: #91A09A;
  transition: color 0.2s ease;
}

.footer-links-list a:hover {
  color: var(--signal-soft);
}

.footer-friendly-bar {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 1.25rem 0;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.footer-friendly-label {
  font-size: 0.875rem;
  color: var(--muted);
}

.footer-friendly-links {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.footer-friendly-links a {
  font-size: 0.875rem;
  color: var(--body);
}

.footer-friendly-links a:hover {
  color: var(--signal-soft);
}

.footer-bottom-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--muted);
  flex-wrap: wrap;
  gap: 1rem;
}

/* ==========================================================================
   ARTICLE PAGE STYLES
   ========================================================================== */
.article-page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 3rem;
  padding: 3rem 0 5rem;
  align-items: start;
}

.article-content-wrapper {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 3rem 2.5rem;
}

.breadcrumb-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--muted);
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.breadcrumb-nav a {
  color: var(--muted);
}

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

.breadcrumb-nav span.sep {
  color: var(--border-light);
}

.article-header {
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1.75rem;
}

.article-header h1 {
  font-size: clamp(1.8rem, 3.2vw, 2.5rem);
  color: var(--text);
  margin-top: 0.75rem;
  margin-bottom: 1rem;
  line-height: 1.3;
}

.article-meta-row {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  font-size: 0.875rem;
  color: var(--muted);
  flex-wrap: wrap;
}

.article-meta-row time {
  color: var(--body);
}

/* Quick Conclusion Box */
.quick-conclusion-box {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-left: 3px solid var(--signal);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.5rem 1.75rem;
  margin-bottom: 2.5rem;
}

.quick-conclusion-box h4 {
  font-size: 1.05rem;
  color: var(--signal-soft);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.quick-conclusion-box p {
  font-size: 1.05rem;
  color: var(--text);
  margin: 0;
  line-height: 1.8;
}

/* Article Body Typography */
.article-body-content h2 {
  font-size: 1.6rem;
  color: var(--text);
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(49, 64, 68, 0.4);
}

.article-body-content h3 {
  font-size: 1.25rem;
  color: var(--text);
  margin-top: 1.75rem;
  margin-bottom: 0.75rem;
}

.article-body-content p {
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--body);
}

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

.article-body-content li {
  color: var(--body);
  margin-bottom: 0.5rem;
}

.article-alert-note {
  background: rgba(91, 155, 152, 0.08);
  border: 1px solid rgba(91, 155, 152, 0.3);
  border-left: 3px solid var(--signal);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-sm);
  margin: 1.75rem 0;
}

.article-alert-note p {
  margin: 0;
  color: var(--text);
  font-size: 0.95rem;
}

.article-alert-warning {
  background: rgba(142, 90, 85, 0.08);
  border: 1px solid rgba(142, 90, 85, 0.35);
  border-left: 3px solid var(--error);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-sm);
  margin: 1.75rem 0;
}

.article-alert-warning p {
  margin: 0;
  color: var(--text);
  font-size: 0.95rem;
}

/* Article Sidebar TOC */
.article-sidebar-sticky {
  position: sticky;
  top: calc(var(--header-height) + 2rem);
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  max-height: calc(100vh - var(--header-height) - 4rem);
  overflow-y: auto;
}

.article-sidebar-sticky h4 {
  font-size: 0.9375rem;
  color: var(--text);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

.toc-nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.toc-nav-list a {
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.5;
  display: block;
}

.toc-nav-list a:hover {
  color: var(--signal-soft);
}

.toc-nav-list a.is-active {
  color: var(--signal);
  font-weight: 600;
}

/* Related Articles Box */
.related-reads-section {
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.related-reads-section h4 {
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 1.25rem;
}

.related-reads-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.related-read-card {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  transition: all 0.2s ease;
}

.related-read-card:hover {
  border-color: var(--signal);
  transform: translateY(-2px);
}

.related-read-card h5 {
  font-size: 1rem;
  color: var(--text);
  margin-bottom: 0.35rem;
}

.related-read-card p {
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0;
}

/* ==========================================================================
   CATEGORY PAGE STYLES
   ========================================================================== */
.category-hero {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 3.5rem 0 3rem;
}

.category-hero-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.category-hero h1 {
  font-size: clamp(2rem, 3.5vw, 3rem);
  color: var(--text);
  margin-bottom: 1rem;
  line-height: 1.3;
}

.category-intro-lead {
  font-size: 1.15rem;
  color: var(--body);
  max-width: 820px;
  line-height: 1.85;
  margin-bottom: 2rem;
}

.category-quick-entries {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.category-entry-box {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
}

.category-entry-box h4 {
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.category-entry-box p {
  font-size: 0.875rem;
  color: var(--muted);
  margin: 0;
}

.category-articles-section {
  padding: 4rem 0;
}

/* ==========================================================================
   PAGE-SPECIFIC: ABOUT, TERMS, PRIVACY, 404, SITEMAP
   ========================================================================== */
.page-document-wrapper {
  max-width: 880px;
  margin: 3rem auto 5rem;
  padding: 3rem 2.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.page-document-wrapper h1 {
  font-size: clamp(2rem, 3vw, 2.75rem);
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1rem;
}

.page-document-wrapper h2 {
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  color: var(--signal-soft);
}

.error-404-container {
  text-align: center;
  padding: 5rem 1.5rem;
  max-width: 720px;
  margin: 0 auto;
}

.error-404-num {
  font-size: 6rem;
  font-family: var(--font-mono);
  font-weight: 900;
  color: rgba(91, 155, 152, 0.2);
  line-height: 1;
  margin-bottom: 1rem;
}

.error-404-links-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 2rem;
  text-align: left;
}

.error-link-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.error-link-card:hover {
  border-color: var(--signal);
}

/* Sitemap List Styles */
.sitemap-group {
  margin-bottom: 2.5rem;
}

.sitemap-group h3 {
  font-size: 1.25rem;
  color: var(--signal-soft);
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

.sitemap-list {
  list-style: none;
  padding-left: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}

.sitemap-list a {
  color: var(--body);
  font-size: 0.95rem;
}

.sitemap-list a:hover {
  color: var(--signal);
}

/* ==========================================================================
   RESPONSIVE DESIGN (Testing at 1440, 1024, 768, 430, 390, 375)
   ========================================================================== */
@media (max-width: 1200px) {
  .nav-desktop {
    gap: 0.75rem;
  }
  .nav-link {
    font-size: 0.8125rem;
  }
  .sequence-bar-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .footer-columns-grid {
    grid-template-columns: 1.2fr repeat(2, 1fr);
    row-gap: 2rem;
  }
}

@media (max-width: 1024px) {
  .nav-desktop, .header-cta {
    display: none;
  }
  .mobile-menu-btn {
    display: block;
  }
  .hero-bottom-grid {
    grid-template-columns: 1fr;
  }
  .client-theater-spread {
    grid-template-columns: 1fr;
  }
  .article-page-layout {
    grid-template-columns: 1fr;
  }
  .article-sidebar-sticky {
    position: static;
    max-height: none;
    margin-bottom: 2rem;
  }
  .problem-clusters-grid {
    grid-template-columns: 1fr;
  }
  .conclusion-report-tier {
    grid-template-columns: 150px 1fr auto;
    gap: 1.25rem;
  }
  .tier-action {
    grid-column: span 3;
    text-align: left;
    margin-top: 0.5rem;
  }
  .width-75-right, .width-90-left, .width-60-center {
    width: 100%;
    max-width: 100%;
    margin: 0;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 62px;
  }
  .theater-curtain {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
  .curtain-master .curtain-left {
    max-width: 100%;
  }
  .curtain-master .curtain-right {
    text-align: left;
    align-items: flex-start;
  }
  .curtain-huge-num {
    display: none;
  }
  .curtain-nodes {
    grid-template-columns: 1fr;
  }
  .curtain-half-divider {
    display: none;
  }
  .curtain-tools {
    grid-template-columns: 1fr;
  }
  .tool-entry-link {
    border-left: none;
    border-top: 1px solid var(--border);
    padding-top: 0.75rem;
  }
  .tool-entry-link:first-child {
    border-top: none;
    padding-top: 0;
  }
  .curtain-devices {
    grid-template-columns: 1fr;
  }
  .sequence-bar-grid {
    grid-template-columns: 1fr;
  }
  .break-diagram-screen {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .break-line-interrupted {
    width: 2px;
    height: 40px;
    background: repeating-linear-gradient(180deg, var(--signal) 0, var(--signal) 6px, transparent 6px, transparent 12px);
  }
  .checkpoints-grid {
    grid-template-columns: 1fr;
  }
  .ai-problem-screen {
    grid-template-columns: 1fr;
  }
  .ai-giant-text {
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding-right: 0;
    padding-bottom: 1rem;
    font-size: 4rem;
  }
  .broadcast-lane {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  .client-issues-list {
    grid-template-columns: 1fr;
  }
  .screens-trio, .slender-screens-trio {
    grid-template-columns: 1fr;
  }
  .device-comparison-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .device-reasons-grid {
    grid-template-columns: 1fr 1fr;
  }
  .switch-binary-grid {
    grid-template-columns: 1fr;
  }
  .conclusion-report-tier {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .tier-pricing-signal, .tier-action {
    text-align: left;
  }
  .category-quick-entries {
    grid-template-columns: 1fr;
  }
  .related-reads-grid {
    grid-template-columns: 1fr;
  }
  .sitemap-list {
    grid-template-columns: 1fr;
  }
  .error-404-links-grid {
    grid-template-columns: 1fr;
  }
  .footer-columns-grid {
    grid-template-columns: 1fr;
  }
  .article-content-wrapper, .page-document-wrapper {
    padding: 1.75rem 1.25rem;
  }
}

@media (max-width: 430px) {
  html {
    font-size: 15px;
  }
  .container, .header-container, .hero-theater-container, .category-hero-container {
    padding: 0 1rem;
  }
  .device-reasons-grid {
    grid-template-columns: 1fr;
  }
  .decay-axis {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }
  .decay-bars {
    margin: 0;
    width: 100%;
  }
  .decay-factors-grid {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   ACCESSIBILITY & PREFERS-REDUCED-MOTION
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .theater-curtain:hover {
    transform: none !important;
  }
  .archive-entry-link:hover, .btn-signal:hover .arrow, .btn-signal-primary:hover .arrow {
    transform: none !important;
  }
}

/* Print Styles */
@media print {
  .site-header, .site-footer, .header-cta, .btn-signal-primary, .btn-signal {
    display: none !important;
  }
  body {
    background: #FFFFFF !important;
    color: #000000 !important;
  }
  .article-content-wrapper {
    border: none !important;
    background: #FFFFFF !important;
  }
}