/* ==========================================================================
   高速VPN (GAOSU VPN) - 高速VPN机场 (VPN AIRPORT NETWORK)
   Style: Modern Mainframe + Futuristic Data Plans + Modern Professional Design
   Palette: Cream Gray (#EAE8DF), Professional Black (#18181A), Signal Orange (#FF5500), Terminal Green (#00E676)
   ========================================================================== */

:root {
  --bg-cream: #EAE8DF;
  --bg-cream-light: #F4F3ED;
  --bg-cream-dark: #DDD9CD;
  --chassis-black: #18181A;
  --chassis-darker: #0E0E10;
  --chassis-panel: #232326;
  --chassis-border: #36363B;
  --chassis-light: #4A4A52;
  --signal-orange: #FF5500;
  --signal-orange-glow: rgba(255, 85, 0, 0.35);
  --signal-orange-dark: #D44400;
  --terminal-green: #00E676;
  --terminal-green-glow: rgba(0, 230, 118, 0.4);
  --terminal-amber: #FFB300;
  --terminal-red: #FF3344;
  --text-primary: #18181A;
  --text-muted: #5D5D63;
  --text-on-dark: #EAE8DF;
  --text-on-dark-muted: #9C9CA4;
  --font-mono: "JetBrains Mono", "SF Mono", "Roboto Mono", "Courier New", monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --grid-line: rgba(24, 24, 26, 0.08);
  --shadow-chassis: 0 10px 30px rgba(0, 0, 0, 0.12), 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-inset-panel: inset 0 2px 6px rgba(0, 0, 0, 0.3);
  --border-radius-sm: 3px;
  --border-radius-md: 6px;
  --transition-normal: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg-cream);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.65;
  background-image: 
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 32px 32px;
  background-position: -1px -1px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Typography Elements */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition-normal);
}

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

code, pre, .mono {
  font-family: var(--font-mono);
}

.container {
  width: 100%;
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Professional Corner Crosshairs & Labels */
.technical-border {
  position: relative;
  border: 1px solid var(--chassis-black);
}

.technical-border::before,
.technical-border::after {
  content: "+";
  position: absolute;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 900;
  color: var(--chassis-black);
  line-height: 1;
}

.technical-border::before {
  top: -6px;
  left: -6px;
}

.technical-border::after {
  bottom: -6px;
  right: -6px;
}

/* Professional Plates & Labels */
.plate-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  background: var(--chassis-black);
  color: var(--bg-cream);
  border-radius: var(--border-radius-sm);
  border-left: 3px solid var(--signal-orange);
}

.plate-tag.light {
  background: var(--bg-cream-dark);
  color: var(--chassis-black);
  border: 1px solid var(--chassis-black);
}

.plate-tag .led {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--terminal-green);
  box-shadow: 0 0 6px var(--terminal-green);
  animation: pulse-led 2s infinite ease-in-out;
}

.plate-tag .led.amber {
  background: var(--terminal-amber);
  box-shadow: 0 0 6px var(--terminal-amber);
}

@keyframes pulse-led {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

/* Header & Navigation Bar */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(234, 232, 223, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 2px solid var(--chassis-black);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}

.brand-icon-reel {
  width: 36px;
  height: 36px;
  background: var(--chassis-black);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  box-shadow: 0 0 0 2px var(--bg-cream), 0 0 0 4px var(--chassis-black);
}

.brand-icon-reel svg {
  width: 22px;
  height: 22px;
  animation: spin-reel 8s linear infinite;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  line-height: 1.1;
  font-weight: 900;
  color: var(--chassis-black);
}

.brand-subtitle {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  color: var(--signal-orange);
  text-transform: uppercase;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-link {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--chassis-black);
  position: relative;
  padding: 6px 0;
}

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

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: 2px solid var(--chassis-black);
  padding: 6px;
  cursor: pointer;
  border-radius: var(--border-radius-sm);
}

/* Mechanical Push Button & CTA */
.btn-mech {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 700;
  padding: 10px 20px;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  border: 2px solid var(--chassis-black);
  transition: transform 0.1s ease, box-shadow 0.1s ease, background 0.2s ease;
  box-shadow: 3px 3px 0 var(--chassis-black);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  user-select: none;
}

.btn-mech:hover {
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 var(--chassis-black);
}

.btn-mech:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--chassis-black);
}

.btn-orange {
  background: var(--signal-orange);
  color: #FFF;
}

.btn-orange:hover {
  background: var(--signal-orange-dark);
}

.btn-dark {
  background: var(--chassis-black);
  color: var(--bg-cream);
}

.btn-dark:hover {
  background: var(--chassis-panel);
}

.btn-outline {
  background: transparent;
  color: var(--chassis-black);
}

.btn-outline:hover {
  background: var(--bg-cream-dark);
}

.btn-sm {
  padding: 6px 12px;
  font-size: 0.78rem;
}

.btn-lg {
  padding: 14px 28px;
  font-size: 1rem;
}

/* ==========================================================================
   Hero Section - VPN VPN Airport Mainframe
   ========================================================================== */
.hero-section {
  padding: 60px 0 80px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 0.78fr 1.22fr;
  gap: 28px;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.hero-badge-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.hero-title {
  font-size: 3rem;
  line-height: 1.15;
  font-weight: 900;
  color: var(--chassis-black);
  letter-spacing: -0.03em;
}

.hero-title .highlight-orange {
  color: var(--signal-orange);
  position: relative;
  display: inline-block;
}

.hero-description {
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--text-muted);
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-top: 8px;
}

.hero-metrics-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 16px;
  padding: 16px;
  background: var(--bg-cream-light);
  border: 1px solid var(--chassis-black);
  box-shadow: 4px 4px 0 rgba(24, 24, 26, 0.08);
}

.metric-item {
  display: flex;
  flex-direction: column;
}

.metric-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.metric-val {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--chassis-black);
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.metric-val small {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--signal-orange);
}

/* Mainframe VPN Machine Visualizer */
.mainframe-machine {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 18px;
  align-items: stretch;
  position: relative;
}

.machine-console {
  background: var(--chassis-black);
  border-radius: var(--border-radius-md);
  border: 3px solid var(--chassis-darker);
  box-shadow: var(--shadow-chassis), 0 0 0 1px #4A4A52;
  color: var(--text-on-dark);
  padding: 24px;
  position: relative;
  overflow: hidden;
}

.machine-console::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: repeating-linear-gradient(
    45deg,
    var(--signal-orange),
    var(--signal-orange) 10px,
    var(--chassis-darker) 10px,
    var(--chassis-darker) 20px
  );
}

.machine-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--chassis-border);
  padding-bottom: 14px;
  margin-bottom: 20px;
}

.machine-nameplate {
  display: flex;
  flex-direction: column;
}

.machine-model {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--signal-orange);
  letter-spacing: 0.1em;
}

.machine-serial {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-on-dark-muted);
  letter-spacing: 0.05em;
}

.machine-status-indicators {
  display: flex;
  gap: 12px;
}

.status-lamp {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--text-on-dark-muted);
}

.lamp-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #333;
}

.lamp-dot.green.active {
  background: var(--terminal-green);
  box-shadow: 0 0 10px var(--terminal-green);
}

.lamp-dot.orange.active {
  background: var(--signal-orange);
  box-shadow: 0 0 10px var(--signal-orange);
  animation: pulse-led 1s infinite alternate;
}

/* VPN Reels Chamber */
.node-chamber {
  background: var(--chassis-panel);
  border: 2px solid var(--chassis-border);
  border-radius: var(--border-radius-sm);
  padding: 24px 16px;
  position: relative;
  box-shadow: var(--shadow-inset-panel);
}

.node-reels-assembly {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  min-height: 180px;
}

/* VPN Ribbon Path */
.node-ribbon-path {
  position: absolute;
  top: 50%;
  left: 60px;
  right: 60px;
  height: 6px;
  background: #111;
  border-top: 1px solid #444;
  border-bottom: 1px solid #444;
  transform: translateY(-50%);
  z-index: 1;
  overflow: hidden;
}

.node-ribbon-data {
  position: absolute;
  top: 0;
  left: 0;
  width: 200%;
  height: 100%;
  background: repeating-linear-gradient(
    90deg,
    transparent,
    transparent 10px,
    var(--terminal-green) 10px,
    var(--terminal-green) 18px
  );
  opacity: 0.7;
  animation: node-flow 4s linear infinite;
}

.node-ribbon-data.fast {
  animation-duration: 0.8s;
  background: repeating-linear-gradient(
    90deg,
    transparent,
    transparent 8px,
    var(--signal-orange) 8px,
    var(--signal-orange) 16px
  );
}

@keyframes node-flow {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* Physical Reel Wheels */
.reel-spool {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: radial-gradient(circle, #2C2C32 25%, #18181B 65%, #101012 100%);
  border: 4px solid #4A4A54;
  box-shadow: 0 4px 15px rgba(0,0,0,0.6), inset 0 0 10px rgba(0,0,0,0.8);
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
}

.reel-spool.spinning {
  animation: spin-reel 5s linear infinite;
}

.reel-spool.spinning-fast {
  animation: spin-reel 0.8s linear infinite;
}

@keyframes spin-reel {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.reel-core {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: #1A1A1E;
  border: 3px solid var(--signal-orange);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: inset 0 0 6px rgba(0,0,0,0.9);
}

.reel-center-spindle {
  width: 16px;
  height: 16px;
  background: #EAE8DF;
  border-radius: 50%;
  border: 2px solid #111;
}

.reel-cutout {
  position: absolute;
  width: 24px;
  height: 24px;
  background: var(--chassis-panel);
  border-radius: 50%;
  border: 1px solid #555;
}

.reel-cutout-1 { top: 12px; }
.reel-cutout-2 { bottom: 12px; }
.reel-cutout-3 { left: 12px; }
.reel-cutout-4 { right: 12px; }

/* VPN Head Assembly (Middle) */
.node-head-block {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 3;
  width: 80px;
  height: 70px;
  background: #18181A;
  border: 2px solid #5A5A64;
  border-radius: var(--border-radius-sm);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 10px rgba(0,0,0,0.7);
}

.head-sensor {
  width: 24px;
  height: 8px;
  background: var(--signal-orange);
  margin-bottom: 6px;
  box-shadow: 0 0 8px var(--signal-orange);
  border-radius: 1px;
}

.head-label {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--terminal-green);
  font-weight: 700;
  letter-spacing: 0.05em;
}

/* Mechanical Flap Counter & LCD Readout */
.machine-instrument-panel {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 16px;
  margin-top: 18px;
  align-items: stretch;
}

.mechanical-counter-box {
  background: #0E0E10;
  border: 2px solid #333338;
  padding: 12px 14px;
  border-radius: var(--border-radius-sm);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.counter-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-on-dark-muted);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.counter-digits-strip {
  display: flex;
  align-items: center;
  gap: 3px;
  font-family: var(--font-mono);
}

.counter-digit {
  background: #1A1A1E;
  color: var(--terminal-green);
  font-size: 1.4rem;
  font-weight: 900;
  padding: 2px 6px;
  border-radius: 2px;
  border: 1px solid #333;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.8);
  min-width: 28px;
  text-align: center;
  text-shadow: 0 0 8px var(--terminal-green-glow);
}

.counter-unit {
  font-size: 0.8rem;
  color: var(--signal-orange);
  font-weight: 700;
  margin-left: 6px;
}

/* Route VPN Cartridge Selector */
.cartridge-rack {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.cartridge-rack-title {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-on-dark-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.cartridge-selector-list {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.node-cartridge-btn {
  background: #232326;
  border: 1px solid #4A4A52;
  color: var(--text-on-dark);
  padding: 6px 10px;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
  transition: var(--transition-normal);
}

.node-cartridge-btn:hover,
.node-cartridge-btn.active {
  background: #33333A;
  border-color: var(--signal-orange);
  color: #FFF;
}

.node-cartridge-btn .color-strip {
  width: 4px;
  height: 14px;
  border-radius: 1px;
}

.node-cartridge-btn .color-strip.hk { background: #FF5500; }
.node-cartridge-btn .color-strip.jp { background: #00E676; }
.node-cartridge-btn .color-strip.sg { background: #00B0FF; }
.node-cartridge-btn .color-strip.us { background: #E040FB; }
.node-cartridge-btn .color-strip.eu { background: #FFD600; }

/* Interactive Speedtest Action & Receipt Output */
.speedtest-action-bar {
  margin-top: 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px solid var(--chassis-border);
}

.btn-speedtest {
  flex: 1;
  background: var(--signal-orange);
  color: #FFF;
  border: 2px solid #FF8844;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 0.85rem;
  padding: 10px 16px;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-shadow: 0 4px 0 #9E3300;
  text-transform: uppercase;
  transition: all 0.15s ease;
}

.btn-speedtest:hover {
  background: #FF6611;
  transform: translateY(-1px);
  box-shadow: 0 5px 0 #9E3300;
}

.btn-speedtest:active {
  transform: translateY(3px);
  box-shadow: 0 1px 0 #9E3300;
}

.btn-speedtest.running {
  background: #118844;
  border-color: var(--terminal-green);
  box-shadow: 0 4px 0 #084422;
}

/* Thermal Printed VPN Receipt */
.thermal-receipt-slot {
  margin-top: 0;
  position: relative;
  background: #0E0E10;
  border: 4px solid #2A2A30;
  border-radius: var(--border-radius-sm);
  overflow: hidden;
  min-height: 100%;
  display: flex;
  align-items: flex-start;
}

.thermal-paper {
  background: #FFFDE8;
  color: #1A1A1A;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 16px;
  box-shadow: 0 6px 12px rgba(0,0,0,0.4);
  position: relative;
  border-bottom: 5px dashed #B8B59E;
  transform: translateY(-100%);
  transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  display: none;
  width: 100%;
  min-height: 100%;
}

.thermal-paper.ejected {
  display: block;
  transform: translateY(0);
  animation: slide-receipt 0.7s ease-out forwards;
}

@keyframes slide-receipt {
  0% { transform: translateY(-90%); opacity: 0.3; }
  100% { transform: translateY(0); opacity: 1; }
}

.receipt-header {
  text-align: center;
  border-bottom: 1px dashed #777;
  padding-bottom: 8px;
  margin-bottom: 8px;
  font-weight: 800;
}

.receipt-line {
  display: flex;
  justify-content: space-between;
  margin: 4px 0;
}

.receipt-barcode {
  text-align: center;
  font-size: 1.2rem;
  letter-spacing: 0.25em;
  font-weight: 900;
  margin-top: 8px;
  opacity: 0.7;
}

/* ==========================================================================
   Section: Core Advantages (机场网络核心优势)
   ========================================================================== */
.section-padding {
  padding: 90px 0;
}

.section-head {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 56px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.section-head.text-left {
  text-align: left;
  align-items: flex-start;
  margin: 0 0 40px;
}

.section-title {
  font-size: 2.3rem;
  line-height: 1.25;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
}

.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.advantage-card {
  background: var(--bg-cream-light);
  border: 2px solid var(--chassis-black);
  padding: 32px 24px;
  border-radius: var(--border-radius-sm);
  position: relative;
  box-shadow: 5px 5px 0 var(--chassis-black);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
}

.advantage-card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--chassis-black);
}

.card-index {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--signal-orange);
  font-weight: 800;
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.card-icon-box {
  width: 52px;
  height: 52px;
  background: var(--chassis-black);
  color: var(--bg-cream);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius-sm);
  margin-bottom: 20px;
  border: 1px solid var(--chassis-border);
}

.card-icon-box svg {
  width: 28px;
  height: 28px;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: 12px;
  line-height: 1.3;
}

.card-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 18px;
  flex-grow: 1;
}

.card-specs {
  border-top: 1px dashed rgba(24, 24, 26, 0.2);
  padding-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--chassis-black);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.spec-row {
  display: flex;
  justify-content: space-between;
}

.spec-row span:first-child {
  color: var(--text-muted);
}

.spec-row span:last-child {
  font-weight: 700;
}

/* ==========================================================================
   Section: Cartridge Pricing Plans (机场信息盒套餐价格)
   ========================================================================== */
.pricing-section {
  background: #E2DFD3;
  border-top: 2px solid var(--chassis-black);
  border-bottom: 2px solid var(--chassis-black);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.cartridge-card {
  background: var(--bg-cream-light);
  border: 2px solid var(--chassis-black);
  border-radius: var(--border-radius-md);
  box-shadow: 6px 6px 0 var(--chassis-black);
  position: relative;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.cartridge-card:hover {
  transform: translateY(-4px);
  box-shadow: 8px 8px 0 var(--chassis-black);
}

.cartridge-card.featured {
  border: 3px solid var(--signal-orange);
  box-shadow: 6px 6px 0 var(--signal-orange);
}

.cartridge-card.featured .cartridge-top-bar {
  background: var(--signal-orange);
  color: #FFF;
}

.cartridge-top-bar {
  background: var(--chassis-black);
  color: var(--bg-cream);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
}

.write-protect-notch {
  width: 14px;
  height: 8px;
  border: 1px solid currentColor;
  background: rgba(255,255,255,0.2);
}

.cartridge-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.cartridge-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 800;
  color: var(--signal-orange);
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

.cartridge-name {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.cartridge-price {
  display: flex;
  align-items: baseline;
  gap: 4px;
  font-family: var(--font-mono);
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--chassis-black);
  margin: 12px 0 20px;
}

.cartridge-price .currency {
  font-size: 1.2rem;
}

.cartridge-price .period {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
}

.cartridge-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
  flex-grow: 1;
}

.cartridge-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-primary);
}

.cartridge-features li svg {
  width: 18px;
  height: 18px;
  color: var(--signal-orange);
  flex-shrink: 0;
}

.cartridge-node-window {
  height: 38px;
  background: #111;
  border-radius: var(--border-radius-sm);
  border: 1px solid #444;
  margin-bottom: 20px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-around;
  padding: 0 16px;
  overflow: hidden;
}

.cartridge-node-window::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 30px;
  right: 30px;
  height: 2px;
  background: #555;
}

.window-spool-hole {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #252525;
  border: 2px dashed #888;
  z-index: 1;
}

/* ==========================================================================
   Section: Target Audience (适合人群)
   ========================================================================== */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.audience-box {
  background: var(--bg-cream-light);
  border: 1px solid var(--chassis-black);
  padding: 24px 20px;
  box-shadow: 4px 4px 0 rgba(24, 24, 26, 0.1);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

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

.audience-title {
  font-size: 1.15rem;
  font-weight: 800;
}

.audience-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   Section: Tutorial Hub (Clash / Clash Party / Mihomo / Shadowrocket)
   ========================================================================== */
.tutorial-section {
  background: var(--chassis-black);
  color: var(--bg-cream);
  border-top: 2px solid var(--chassis-darker);
  border-bottom: 2px solid var(--chassis-darker);
}

.tutorial-section .section-title {
  color: var(--bg-cream);
}

.tutorial-section .section-subtitle {
  color: var(--text-on-dark-muted);
}

.tutorial-tabs-nav {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.tut-tab-btn {
  background: var(--chassis-panel);
  color: var(--text-on-dark-muted);
  border: 1px solid var(--chassis-border);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  padding: 10px 20px;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: var(--transition-normal);
}

.tut-tab-btn.active,
.tut-tab-btn:hover {
  background: var(--signal-orange);
  color: #FFF;
  border-color: var(--signal-orange);
}

.tutorial-card-wrapper {
  background: var(--chassis-darker);
  border: 2px solid var(--chassis-border);
  border-radius: var(--border-radius-md);
  padding: 36px;
  position: relative;
}

.tutorial-steps-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.tut-step-box {
  background: var(--chassis-panel);
  border: 1px solid #3A3A42;
  border-radius: var(--border-radius-sm);
  padding: 20px;
  display: flex;
  flex-direction: column;
  position: relative;
}

.tut-step-num {
  font-family: var(--font-mono);
  font-size: 1.8rem;
  font-weight: 900;
  color: var(--signal-orange);
  line-height: 1;
  margin-bottom: 12px;
}

.tut-step-title {
  font-size: 1.05rem;
  font-weight: 800;
  color: #FFF;
  margin-bottom: 8px;
}

.tut-step-desc {
  font-size: 0.85rem;
  color: var(--text-on-dark-muted);
  line-height: 1.6;
}

.code-snippet-box {
  margin-top: 24px;
  background: #000;
  border: 1px solid var(--terminal-green);
  border-radius: var(--border-radius-sm);
  padding: 14px 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.code-snippet-text {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--terminal-green);
  overflow-x: auto;
  white-space: nowrap;
}

/* ==========================================================================
   Section: User Reviews (用户评价 / 运行日志)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-cream-light);
  border: 2px solid var(--chassis-black);
  padding: 24px;
  box-shadow: 4px 4px 0 var(--chassis-black);
  display: flex;
  flex-direction: column;
}

.review-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.user-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 800;
  color: var(--chassis-black);
}

.user-avatar-tag {
  width: 28px;
  height: 28px;
  background: var(--chassis-black);
  color: var(--bg-cream);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  border-radius: 2px;
}

.review-rating {
  color: var(--signal-orange);
}

.review-text {
  font-size: 0.92rem;
  line-height: 1.65;
  color: var(--text-primary);
  margin-bottom: 16px;
  flex-grow: 1;
}

.review-verified {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  border-top: 1px dashed rgba(24, 24, 26, 0.15);
  padding-top: 10px;
  display: flex;
  justify-content: space-between;
}

/* ==========================================================================
   Section: FAQ (常见问题解答)
   ========================================================================== */
.faq-accordion {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-cream-light);
  border: 2px solid var(--chassis-black);
  border-radius: var(--border-radius-sm);
  box-shadow: 3px 3px 0 var(--chassis-black);
  overflow: hidden;
  transition: var(--transition-normal);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 18px 24px;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.faq-toggle-icon {
  width: 22px;
  height: 22px;
  background: var(--chassis-black);
  color: var(--bg-cream);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  border-radius: 2px;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(45deg);
  background: var(--signal-orange);
  color: #FFF;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
  padding: 0 24px;
  font-size: 0.94rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  padding: 0 24px 20px;
  max-height: 600px;
}

/* ==========================================================================
   Section: Articles Directory (SEO文章目录)
   ========================================================================== */
.articles-section {
  background: var(--bg-cream-dark);
  border-top: 2px solid var(--chassis-black);
  border-bottom: 2px solid var(--chassis-black);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.article-card {
  background: var(--bg-cream-light);
  border: 2px solid var(--chassis-black);
  padding: 24px;
  box-shadow: 4px 4px 0 var(--chassis-black);
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
}

.article-card:hover {
  transform: translateY(-3px);
  box-shadow: 6px 6px 0 var(--chassis-black);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.article-category {
  background: var(--chassis-black);
  color: var(--bg-cream);
  padding: 2px 8px;
  font-weight: 700;
  border-radius: 2px;
}

.article-title {
  font-size: 1.25rem;
  font-weight: 800;
  line-height: 1.35;
  margin-bottom: 10px;
}

.article-title a:hover {
  color: var(--signal-orange);
}

.article-excerpt {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px dashed rgba(24, 24, 26, 0.15);
  padding-top: 12px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.read-more-link {
  font-weight: 700;
  color: var(--signal-orange);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.read-more-link:hover {
  text-decoration: underline;
}

/* ==========================================================================
   Article Single Page Template Styles
   ========================================================================== */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.breadcrumbs a:hover {
  color: var(--signal-orange);
}

.article-container {
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-cream-light);
  border: 2px solid var(--chassis-black);
  padding: 48px 40px;
  box-shadow: 6px 6px 0 var(--chassis-black);
  margin-bottom: 60px;
}

.article-header {
  border-bottom: 2px solid var(--chassis-black);
  padding-bottom: 24px;
  margin-bottom: 32px;
}

.article-main-title {
  font-size: 2.3rem;
  font-weight: 900;
  line-height: 1.25;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.article-info-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #242426;
}

.article-content h2 {
  font-size: 1.6rem;
  margin: 40px 0 18px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--chassis-black);
  position: relative;
}

.article-content h2::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--signal-orange);
}

.article-content h3 {
  font-size: 1.25rem;
  margin: 28px 0 14px;
  color: var(--chassis-black);
}

.article-content p {
  margin-bottom: 20px;
}

.article-content ul, .article-content ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

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

.article-content blockquote {
  background: var(--bg-cream-dark);
  border-left: 4px solid var(--signal-orange);
  padding: 16px 20px;
  margin: 24px 0;
  font-style: italic;
  font-size: 0.98rem;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 0.92rem;
  background: #FFF;
  border: 2px solid var(--chassis-black);
}

.article-content th, .article-content td {
  padding: 12px 14px;
  border: 1px solid #CCC;
  text-align: left;
}

.article-content th {
  background: var(--chassis-black);
  color: var(--bg-cream);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.05em;
}

.article-content tr:nth-child(even) {
  background: #FAF8F2;
}

.article-cta-box {
  background: var(--chassis-black);
  color: var(--bg-cream);
  padding: 30px;
  border-radius: var(--border-radius-sm);
  margin: 40px 0;
  text-align: center;
  border: 2px solid var(--signal-orange);
}

.article-cta-box h3 {
  color: #FFF;
  font-size: 1.4rem;
  margin-bottom: 10px;
}

.article-cta-box p {
  color: var(--text-on-dark-muted);
  font-size: 0.95rem;
  margin-bottom: 20px;
}

/* Related Articles List in Single Page */
.related-articles-box {
  background: var(--bg-cream-dark);
  border: 1px solid var(--chassis-black);
  padding: 24px;
  margin-top: 40px;
}

.related-articles-box h4 {
  font-size: 1.15rem;
  margin-bottom: 14px;
  font-family: var(--font-mono);
}

.related-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.related-links-list li a {
  color: var(--chassis-black);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
}

.related-links-list li a:hover {
  color: var(--signal-orange);
  padding-left: 4px;
}

/* ==========================================================================
   Footer & Sitemap
   ========================================================================== */
.site-footer {
  background: var(--chassis-black);
  color: var(--text-on-dark);
  border-top: 4px solid var(--signal-orange);
  padding: 60px 0 30px;
  font-size: 0.88rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand-info {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.footer-brand-info p {
  color: var(--text-on-dark-muted);
  line-height: 1.6;
}

.footer-col-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 800;
  color: #FFF;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 18px;
  border-bottom: 1px solid #333;
  padding-bottom: 8px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  color: var(--text-on-dark-muted);
  transition: var(--transition-normal);
}

.footer-links a:hover {
  color: var(--signal-orange);
  padding-left: 4px;
}

.footer-bottom-bar {
  border-top: 1px solid var(--chassis-border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-on-dark-muted);
}

.footer-legal-links {
  display: flex;
  gap: 18px;
}

.footer-legal-links a:hover {
  color: var(--bg-cream);
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .mainframe-machine {
    grid-template-columns: minmax(0, 1fr) 300px;
  }
  .advantages-grid, .pricing-grid, .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .tutorial-steps-grid, .audience-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2.2rem;
  }
  .advantages-grid, .pricing-grid, .reviews-grid, .articles-grid {
    grid-template-columns: 1fr;
  }
  .tutorial-steps-grid, .audience-grid {
    grid-template-columns: 1fr;
  }
  .nav-menu {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-cream);
    flex-direction: column;
    padding: 24px;
    border-bottom: 2px solid var(--chassis-black);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
  }
  .nav-menu.open {
    display: flex;
  }
  .mobile-menu-btn {
    display: block;
  }
  .article-container {
    padding: 28px 18px;
  }
  .article-main-title {
    font-size: 1.8rem;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .machine-instrument-panel {
    grid-template-columns: 1fr;
  }
  .mainframe-machine {
    grid-template-columns: 1fr;
  }
  .thermal-receipt-slot {
    min-height: 24px;
  }
}