/* ==========================================================================
   拼好连机场 (Pingoodlian Airport) - Design System & Subsea Hydraulic Umbilical Core
   Theme: Subsea Hydraulic Umbilical & Cold-Forged Quick-Disconnect (Wet-Mate)
   Canvas: Glacial Shallow Cyan Cold Grey (#EEF4F6) with High-Pressure Mist & Hydro-Glow
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500;700&family=Outfit:wght@400;600;700;800&display=swap');

:root {
  /* Color Palette */
  --bg-glacial-base: #EEF4F6;
  --bg-glacial-surface: #F5F9FA;
  --bg-card-mist: rgba(245, 249, 250, 0.85);
  --bg-card-solid: #FFFFFF;
  
  /* Stainless Steel & Metallic Gradients */
  --steel-light: #F8FAFC;
  --steel-mid: #E2E8F0;
  --steel-dark: #CBD5E1;
  --steel-border: #CBD5E1;
  --steel-shadow: rgba(15, 23, 42, 0.08);

  /* Hydraulic Cyan Hydro-Glow */
  --hydro-cyan: #06B6D4;
  --hydro-cyan-light: #22D3EE;
  --hydro-cyan-glow: rgba(6, 182, 212, 0.35);
  --hydro-deep-blue: #0284C7;
  --hydro-bg-tint: rgba(6, 182, 212, 0.06);

  /* Deep Trench Graphite / Slate */
  --trench-black: #0F172A;
  --trench-slate: #1E293B;
  --trench-muted: #475569;
  --trench-subtle: #64748B;
  --text-primary: #0F172A;
  --text-secondary: #334155;
  --text-muted: #64748B;

  /* Status Accents */
  --status-zero-leak: #10B981;
  --status-zero-leak-bg: rgba(16, 185, 129, 0.12);
  --status-high-press: #06B6D4;
  --status-alert: #EF4444;

  /* Typography */
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-heading: 'Outfit', 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Umbilical Cable Spacing & Shadows */
  --radius-flange: 16px;
  --radius-plug: 8px;
  --shadow-hydraulic: 0 12px 36px -8px rgba(6, 182, 212, 0.15), 0 4px 16px rgba(15, 23, 42, 0.06);
  --shadow-steel-plug: 0 8px 24px rgba(15, 23, 42, 0.1), inset 0 1px 0 rgba(255, 255, 255, 0.9);
  --border-steel: 1px solid rgba(203, 213, 225, 0.8);
}

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

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

body {
  background-color: var(--bg-glacial-base);
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(6, 182, 212, 0.08) 0%, transparent 60%),
    radial-gradient(circle at 100% 50%, rgba(2, 132, 199, 0.05) 0%, transparent 50%),
    repeating-linear-gradient(0deg, transparent, transparent 49px, rgba(203, 213, 225, 0.25) 50px);
  background-size: 100% 100%, 100% 100%, 100% 50px;
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* Subsea Ambient Mist Animation Layer */
.subsea-mist-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  background: 
    radial-gradient(ellipse at 20% 20%, rgba(34, 211, 238, 0.05) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(2, 132, 199, 0.06) 0%, transparent 60%);
  animation: hydroMistPulse 12s ease-in-out infinite alternate;
}

@keyframes hydroMistPulse {
  0% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 0.9; transform: scale(1.05); }
  100% { opacity: 0.6; transform: scale(1); }
}

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

/* Typography Helpers */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--trench-black);
  line-height: 1.25;
}

a {
  color: var(--hydro-deep-blue);
  text-decoration: none;
  transition: all 0.25s ease;
}

a:hover {
  color: var(--hydro-cyan);
}

/* Telemetry Badge */
.telemetry-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 9999px;
  background: rgba(15, 23, 42, 0.05);
  border: 1px solid rgba(6, 182, 212, 0.3);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--trench-slate);
  letter-spacing: 0.5px;
  box-shadow: inset 0 1px 2px rgba(255, 255, 255, 0.6);
}

.telemetry-tag .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--status-zero-leak);
  box-shadow: 0 0 10px var(--status-zero-leak);
  animation: dotPulse 2s infinite;
}

@keyframes dotPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.3); opacity: 0.6; }
}

/* Navigation Header */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(238, 244, 246, 0.9);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(203, 213, 225, 0.6);
  padding: 16px 0;
  transition: background 0.3s ease;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--trench-black);
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, #0F172A 0%, #1E293B 100%);
  border: 1px solid var(--hydro-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--hydro-cyan-light);
  box-shadow: 0 4px 12px rgba(6, 182, 212, 0.25);
}

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

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--trench-slate);
  transition: color 0.2s ease;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: var(--hydro-cyan);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--hydro-cyan);
  transition: width 0.25s ease;
  border-radius: 2px;
}

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

.nav-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: 8px;
  background: linear-gradient(135deg, #0F172A 0%, #0284C7 100%);
  color: #FFFFFF;
  font-weight: 600;
  font-size: 0.9375rem;
  border: 1px solid rgba(34, 211, 238, 0.4);
  box-shadow: 0 4px 14px rgba(2, 132, 199, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.3);
  transition: all 0.25s ease;
  cursor: pointer;
}

.nav-cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(6, 182, 212, 0.45);
  color: #FFFFFF;
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--trench-black);
  cursor: pointer;
}

/* ==========================================================================
   Umbilical & Cold-Forged Quick-Disconnect (Wet-Mate) Components
   ========================================================================== */

/* Umbilical Cable Outer Section Wrapper */
.umbilical-section-card {
  position: relative;
  background: var(--bg-card-solid);
  border-radius: 20px;
  padding: 48px;
  margin-bottom: 40px;
  box-shadow: 0 20px 40px -15px rgba(15, 23, 42, 0.07), inset 0 0 0 1px rgba(203, 213, 225, 0.6);
  overflow: hidden;
}

/* Braided Sheath Extenders on Left and Right */
.umbilical-section-card::before,
.umbilical-section-card::after {
  content: '';
  position: absolute;
  top: 50%;
  width: 32px;
  height: 12px;
  transform: translateY(-50%);
  background: repeating-linear-gradient(45deg, #334155, #334155 4px, #0F172A 4px, #0F172A 8px);
  border: 1px solid var(--steel-border);
  z-index: 2;
}

.umbilical-section-card::before {
  left: 0;
  border-radius: 0 4px 4px 0;
}

.umbilical-section-card::after {
  right: 0;
  border-radius: 4px 0 0 4px;
}

/* Cold-Forged Flange Corner Accents */
.flange-corner {
  position: absolute;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #F8FAFC 0%, #CBD5E1 70%, #64748B 100%);
  box-shadow: inset 0 1px 2px rgba(255, 255, 255, 0.9), 0 2px 4px rgba(15, 23, 42, 0.2);
  border: 1px solid #94A3B8;
  z-index: 3;
}
.flange-top-left { top: 14px; left: 14px; }
.flange-top-right { top: 14px; right: 14px; }
.flange-bottom-left { bottom: 14px; left: 14px; }
.flange-bottom-right { bottom: 14px; right: 14px; }

/* Subsea Hero Section */
.hero-section {
  padding: 60px 0 40px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-content h1 {
  font-size: 3.25rem;
  line-height: 1.15;
  letter-spacing: -1px;
  margin: 20px 0 24px;
}

.hero-content h1 .gradient-text {
  background: linear-gradient(135deg, #0F172A 0%, #0284C7 50%, #06B6D4 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--trench-muted);
  line-height: 1.7;
  margin-bottom: 32px;
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 32px;
  border-radius: 10px;
  background: linear-gradient(135deg, #0F172A 0%, #0284C7 100%);
  color: #FFFFFF;
  font-weight: 700;
  font-size: 1rem;
  border: 1px solid rgba(34, 211, 238, 0.4);
  box-shadow: 0 8px 24px rgba(6, 182, 212, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.4);
  transition: all 0.25s ease;
  cursor: pointer;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(6, 182, 212, 0.45);
  color: #FFFFFF;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 10px;
  background: var(--steel-light);
  color: var(--trench-black);
  font-weight: 600;
  font-size: 1rem;
  border: 1px solid var(--steel-border);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.05);
  transition: all 0.25s ease;
}

.btn-secondary:hover {
  background: #FFFFFF;
  border-color: var(--hydro-cyan);
  transform: translateY(-2px);
}

/* Wet-Mate Interactive Speed Test Widget */
.wet-mate-widget {
  background: linear-gradient(180deg, #1E293B 0%, #0F172A 100%);
  border-radius: 18px;
  padding: 24px;
  border: 1px solid rgba(6, 182, 212, 0.3);
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.25), inset 0 1px 0 rgba(255, 255, 255, 0.1);
  color: #FFFFFF;
  position: relative;
}

.wet-mate-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: 20px;
}

.wet-mate-title {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--hydro-cyan-light);
  display: flex;
  align-items: center;
  gap: 8px;
  letter-spacing: 1px;
}

/* Hydro-Lock Animated Plug Interface */
.hydro-lock-stage {
  position: relative;
  height: 140px;
  background: rgba(15, 23, 42, 0.6);
  border-radius: 12px;
  border: 1px dashed rgba(6, 182, 212, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 20px;
  margin-bottom: 20px;
  overflow: hidden;
}

.lock-cable-left, .lock-cable-right {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  transition: all 0.8s cubic-bezier(0.25, 1, 0.5, 1);
}

.lock-cable-left { left: 10px; }
.lock-cable-right { right: 10px; }

.cable-braid {
  width: 80px;
  height: 28px;
  background: repeating-linear-gradient(45deg, #334155, #334155 6px, #1E293B 6px, #1E293B 12px);
  border-radius: 4px;
  border: 1px solid #475569;
}

.stainless-plug {
  width: 44px;
  height: 40px;
  background: linear-gradient(180deg, #E2E8F0 0%, #94A3B8 50%, #475569 100%);
  border-radius: 6px;
  border: 1px solid #F8FAFC;
  box-shadow: inset 0 1px 2px rgba(255, 255, 255, 0.8);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.plug-ring {
  width: 10px;
  height: 46px;
  background: linear-gradient(90deg, var(--hydro-cyan), var(--hydro-cyan-light));
  border-radius: 3px;
  box-shadow: 0 0 12px var(--hydro-cyan);
  transition: transform 0.5s ease;
}

.wet-mate-widget.locked .lock-cable-left {
  left: calc(50% - 62px);
}
.wet-mate-widget.locked .lock-cable-right {
  right: calc(50% - 62px);
}
.wet-mate-widget.locked .plug-ring {
  transform: rotate(90deg) scale(1.1);
  box-shadow: 0 0 20px var(--hydro-cyan-light);
}

.hydro-spark {
  position: absolute;
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--hydro-cyan-light) 0%, transparent 70%);
  opacity: 0;
  transform: scale(0.2);
  transition: all 0.4s ease;
  pointer-events: none;
}

.wet-mate-widget.locked .hydro-spark {
  opacity: 1;
  transform: scale(1.5);
  animation: hydroBurst 0.6s ease-out forwards;
}

@keyframes hydroBurst {
  0% { opacity: 1; transform: scale(0.3); }
  50% { opacity: 0.9; transform: scale(1.8); }
  100% { opacity: 0; transform: scale(2.4); }
}

/* Status Telemetry Display */
.telemetry-readout {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  background: rgba(15, 23, 42, 0.8);
  padding: 14px;
  border-radius: 10px;
  border: 1px solid rgba(203, 213, 225, 0.1);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  text-align: center;
}

.readout-item .label {
  color: var(--trench-subtle);
  font-size: 0.7rem;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.readout-item .value {
  color: var(--hydro-cyan-light);
  font-weight: 700;
  font-size: 0.9375rem;
}

.trigger-test-btn {
  width: 100%;
  margin-top: 16px;
  padding: 12px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--hydro-cyan) 0%, var(--hydro-deep-blue) 100%);
  border: none;
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(6, 182, 212, 0.3);
  transition: all 0.25s ease;
}

.trigger-test-btn:hover {
  filter: brightness(1.15);
  box-shadow: 0 6px 18px rgba(6, 182, 212, 0.5);
}

/* ==========================================================================
   Core Advantages & Features Section
   ========================================================================== */

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 50px;
}

.section-header .sub-title {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--hydro-deep-blue);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 8px;
  display: block;
}

.section-header h2 {
  font-size: 2.25rem;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.section-header p {
  color: var(--trench-muted);
  font-size: 1.0625rem;
}

/* Grid Layouts for Cards */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.advantage-card {
  background: #FFFFFF;
  border-radius: 16px;
  padding: 32px 28px;
  border: 1px solid var(--steel-border);
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.04);
  position: relative;
  transition: all 0.3s ease;
}

.advantage-card:hover {
  transform: translateY(-6px);
  border-color: var(--hydro-cyan);
  box-shadow: var(--shadow-hydraulic);
}

.card-icon-wrap {
  width: 54px;
  height: 54px;
  border-radius: 12px;
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--hydro-deep-blue);
  font-size: 1.5rem;
  margin-bottom: 20px;
}

.advantage-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.advantage-card p {
  color: var(--trench-muted);
  font-size: 0.9375rem;
  line-height: 1.6;
}

/* ==========================================================================
   Pricing Packages (套餐价格)
   ========================================================================== */

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

.pricing-card {
  background: #FFFFFF;
  border-radius: 18px;
  padding: 36px 30px;
  border: 1px solid var(--steel-border);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.05);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
}

.pricing-card.popular {
  border: 2px solid var(--hydro-cyan);
  box-shadow: 0 16px 40px rgba(6, 182, 212, 0.2);
  transform: translateY(-8px);
}

.popular-badge {
  position: absolute;
  top: -14px;
  right: 24px;
  background: linear-gradient(135deg, var(--hydro-cyan) 0%, var(--hydro-deep-blue) 100%);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 9999px;
  box-shadow: 0 4px 10px rgba(6, 182, 212, 0.4);
}

.pricing-header h3 {
  font-size: 1.35rem;
  margin-bottom: 8px;
}

.pricing-header .plan-desc {
  font-size: 0.875rem;
  color: var(--trench-subtle);
  margin-bottom: 24px;
}

.price-box {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--steel-mid);
}

.price-box .currency {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--trench-black);
}

.price-box .amount {
  font-family: var(--font-heading);
  font-size: 3rem;
  font-weight: 800;
  color: var(--trench-black);
  line-height: 1;
}

.price-box .period {
  font-size: 0.9375rem;
  color: var(--trench-subtle);
}

.feature-list {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.feature-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9375rem;
  color: var(--trench-slate);
  margin-bottom: 14px;
}

.feature-list li i {
  color: var(--status-zero-leak);
  font-size: 1rem;
}

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

.audience-card {
  background: var(--bg-glacial-surface);
  border-radius: 14px;
  padding: 24px 20px;
  border: 1px solid var(--steel-border);
  text-align: center;
  transition: all 0.25s ease;
}

.audience-card:hover {
  background: #FFFFFF;
  border-color: var(--hydro-cyan);
  transform: translateY(-4px);
}

.audience-icon {
  width: 50px;
  height: 50px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: #FFFFFF;
  border: 1px solid var(--steel-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--hydro-deep-blue);
  font-size: 1.25rem;
  box-shadow: 0 4px 10px rgba(15, 23, 42, 0.05);
}

.audience-card h4 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.audience-card p {
  font-size: 0.875rem;
  color: var(--trench-muted);
}

/* ==========================================================================
   Tutorial & Client Hub Section
   ========================================================================== */
.tutorial-preview-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.tutorial-card {
  background: #FFFFFF;
  border-radius: 18px;
  border: 1px solid var(--steel-border);
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.04);
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
}

.tutorial-card:hover {
  transform: translateY(-6px);
  border-color: var(--hydro-cyan);
  box-shadow: var(--shadow-hydraulic);
}

.tutorial-card-body {
  padding: 32px;
}

.tutorial-tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 6px;
  background: rgba(6, 182, 212, 0.1);
  color: var(--hydro-deep-blue);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.tutorial-card h3 {
  font-size: 1.35rem;
  margin-bottom: 12px;
}

.tutorial-card p {
  color: var(--trench-muted);
  font-size: 0.9375rem;
  margin-bottom: 20px;
}

.tutorial-steps-mini {
  list-style: none;
  margin-bottom: 24px;
}

.tutorial-steps-mini li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.875rem;
  color: var(--trench-slate);
  margin-bottom: 8px;
}

.tutorial-steps-mini li span {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--bg-glacial-base);
  color: var(--hydro-deep-blue);
  font-size: 0.75rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;

}

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

.review-card {
  background: #FFFFFF;
  border-radius: 16px;
  padding: 28px;
  border: 1px solid var(--steel-border);
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.03);
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--hydro-cyan) 0%, var(--hydro-deep-blue) 100%);
  color: #FFFFFF;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 10px rgba(6, 182, 212, 0.3);
}

.user-info h5 {
  font-size: 1rem;
  margin-bottom: 2px;
}

.user-info span {
  font-size: 0.75rem;
  color: var(--trench-subtle);
}

.review-rating {
  color: #F59E0B;
  font-size: 0.875rem;
  margin-bottom: 12px;
}

.review-text {
  font-size: 0.9375rem;
  color: var(--trench-slate);
  line-height: 1.6;
}

/* ==========================================================================
   FAQ Section (Accordions)
   ========================================================================== */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: #FFFFFF;
  border-radius: 14px;
  border: 1px solid var(--steel-border);
  overflow: hidden;
  transition: all 0.25s ease;
}

.faq-item.active {
  border-color: var(--hydro-cyan);
  box-shadow: 0 8px 24px rgba(6, 182, 212, 0.12);
}

.faq-question {
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.0625rem;
  color: var(--trench-black);
}

.faq-toggle-icon {
  font-size: 1.25rem;
  color: var(--hydro-cyan);
  transition: transform 0.3s ease;
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
  background: var(--bg-glacial-surface);
}

.faq-answer-inner {
  padding: 20px 24px;
  font-size: 0.9375rem;
  color: var(--trench-slate);
  line-height: 1.7;
  border-top: 1px solid var(--steel-mid);
}

/* ==========================================================================
   Article Index & Matrix Grid
   ========================================================================== */
.articles-matrix-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.article-card-mini {
  background: #FFFFFF;
  border-radius: 14px;
  padding: 24px;
  border: 1px solid var(--steel-border);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.25s ease;
}

.article-card-mini:hover {
  transform: translateY(-4px);
  border-color: var(--hydro-cyan);
  box-shadow: 0 10px 25px rgba(6, 182, 212, 0.12);
}

.article-card-mini h4 {
  font-size: 1.1rem;
  margin-bottom: 10px;
  line-height: 1.4;
}

.article-card-mini p {
  font-size: 0.875rem;
  color: var(--trench-muted);
  margin-bottom: 16px;
  line-height: 1.5;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
  color: var(--trench-subtle);
}

/* ==========================================================================
   Article Single View & Article Layout
   ========================================================================== */
.article-container {
  max-width: 900px;
  margin: 40px auto 60px;
  padding: 0 24px;
}

.article-header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--steel-border);
}

.breadcrumb-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--trench-subtle);
  margin-bottom: 16px;
}

.article-header h1 {
  font-size: 2.5rem;
  line-height: 1.25;
  margin-bottom: 16px;
}

.article-body-content {
  background: #FFFFFF;
  border-radius: 20px;
  padding: 48px;
  border: 1px solid var(--steel-border);
  box-shadow: 0 12px 36px rgba(15, 23, 42, 0.04);
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.article-body-content h2 {
  font-size: 1.65rem;
  margin: 36px 0 18px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--hydro-cyan);
}

.article-body-content h3 {
  font-size: 1.3rem;
  margin: 28px 0 14px;
}

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

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

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

.article-cta-box {
  margin: 40px 0;
  padding: 32px;
  background: linear-gradient(135deg, #0F172A 0%, #1E293B 100%);
  border-radius: 16px;
  border: 1px solid var(--hydro-cyan);
  color: #FFFFFF;
  text-align: center;
  box-shadow: 0 12px 30px rgba(6, 182, 212, 0.2);
}

.article-cta-box h4 {
  color: #FFFFFF;
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.article-cta-box p {
  color: var(--steel-dark);
  margin-bottom: 20px;
}

/* ==========================================================================
   Footer Section
   ========================================================================== */
.footer {
  background: var(--trench-black);
  color: #94A3B8;
  padding: 60px 0 30px;
  border-top: 2px solid var(--hydro-cyan);
  position: relative;
  z-index: 10;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand h3 {
  color: #FFFFFF;
  font-size: 1.35rem;
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: 0.9375rem;
  line-height: 1.6;
}

.footer-col h4 {
  color: #FFFFFF;
  font-size: 1rem;
  margin-bottom: 16px;
}

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

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

.footer-links a {
  color: #94A3B8;
  font-size: 0.875rem;
}

.footer-links a:hover {
  color: var(--hydro-cyan-light);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
}

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

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: #EEF4F6;
    padding: 20px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    flex-direction: column;
    gap: 16px;
  }
  .nav-menu.show {
    display: flex;
  }
  .mobile-toggle {
    display: block;
  }
  .hero-content h1 {
    font-size: 2.25rem;
  }
  .advantages-grid, .pricing-grid, .reviews-grid, .tutorial-preview-grid, .articles-matrix-grid {
    grid-template-columns: 1fr;
  }
  .audience-grid {
    grid-template-columns: 1fr;
  }
  .article-body-content {
    padding: 24px;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}