/* ==========================================================================
   GLADOS Cloud & Network - Quantum Photon Technology Stylesheet
   Theme: 光子隧道 + 量子传态 + 光速科技
   Palette:
     - Main Background: #0F0524 暗紫黑
     - Primary: #FCD34D 光子黄
     - Secondary: #22D3EE 传态青
     - Text: #FFFFFF / rgba(255, 255, 255, 0.6)
   Typography:
     - Headings: Space Grotesk, 700
     - Body: Inter / 思源黑体
   ========================================================================== */


:root {
  --bg-dark: #0F0524;
  --bg-card: rgba(26, 12, 54, 0.72);
  --bg-card-hover: rgba(38, 18, 77, 0.88);
  --border-color: rgba(34, 211, 238, 0.16);
  --border-color-hover: rgba(252, 211, 77, 0.45);
  
  --primary: #FCD34D;        /* 光子黄 */
  --secondary: #22D3EE;      /* 传态青 */
  --primary-glow: rgba(252, 211, 77, 0.6);
  --secondary-glow: rgba(34, 211, 238, 0.7);
  --accent-purple: #a855f7;
  
  --text-main: #FFFFFF;
  --text-muted: rgba(255, 255, 255, 0.6);
  --text-dim: rgba(255, 255, 255, 0.45);
  --success: #22D3EE;
  
  --font-heading: 'Space Grotesk', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --container-width: 1200px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-btn: 12px;
  --transition: all 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  color-scheme: dark;
  overflow-x: hidden;
  width: 100%;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.65;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ==========================================================================
   Full-screen Radial Gradient Yellow / Cyan Glows & Background Animations
   ========================================================================== */

/* Fullscreen Radial Glows */
body::before {
  content: "";
  position: fixed;
  top: -150px;
  left: 15%;
  width: 750px;
  height: 650px;
  background: radial-gradient(circle, rgba(252, 211, 77, 0.16) 0%, rgba(252, 211, 77, 0.04) 40%, transparent 70%);
  z-index: -3;
  pointer-events: none;
  filter: blur(40px);
}

body::after {
  content: "";
  position: fixed;
  top: 150px;
  right: 10%;
  width: 800px;
  height: 700px;
  background: radial-gradient(circle, rgba(34, 211, 238, 0.18) 0%, rgba(34, 211, 238, 0.05) 45%, transparent 70%);
  z-index: -3;
  pointer-events: none;
  filter: blur(50px);
}

/* Subtle Edge-Faded Grid Overlay */
.bg-grid-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(circle at 50% 50%, black 30%, transparent 85%);
  -webkit-mask-image: radial-gradient(circle at 50% 50%, black 30%, transparent 85%);
  pointer-events: none;
  z-index: -2;
}

/* 3 SVG Photon Beams (Diagonal Lines with 2s Dashoffset Flow Animation) */
.bg-beams-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -2;
  overflow: hidden;
}

.bg-beams-svg {
  width: 100%;
  height: 100%;
}

.photon-beam {
  stroke-dasharray: 120 280;
  animation: beamTraverse 2s linear infinite;
}

.photon-beam-yellow {
  stroke: #FCD34D;
  stroke-width: 2.2;
  filter: drop-shadow(0 0 8px rgba(252, 211, 77, 0.8));
}

.photon-beam-cyan {
  stroke: #22D3EE;
  stroke-width: 2.5;
  filter: drop-shadow(0 0 10px rgba(34, 211, 238, 0.85));
  animation-delay: 0.65s;
}

.photon-beam-mixed {
  stroke: #FCD34D;
  stroke-width: 1.8;
  filter: drop-shadow(0 0 8px rgba(34, 211, 238, 0.7));
  animation-delay: 1.3s;
}

@keyframes beamTraverse {
  0% {
    stroke-dashoffset: 800;
  }
  100% {
    stroke-dashoffset: 0;
  }
}

/* 4 Rising Yellow / Cyan Floating Particles from Bottom with Horizontal Drift */
.bg-particles-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -2;
  overflow: hidden;
}

.quantum-particle {
  position: absolute;
  bottom: -30px;
  border-radius: 50%;
  pointer-events: none;
}

.particle-1 {
  left: 14%;
  width: 7px;
  height: 7px;
  background: #FCD34D;
  box-shadow: 0 0 14px #FCD34D, 0 0 24px rgba(252, 211, 77, 0.8);
  animation: riseAndDrift1 6.5s ease-in-out infinite;
}

.particle-2 {
  left: 38%;
  width: 9px;
  height: 9px;
  background: #22D3EE;
  box-shadow: 0 0 16px #22D3EE, 0 0 28px rgba(34, 211, 238, 0.8);
  animation: riseAndDrift2 5.8s ease-in-out infinite 1.4s;
}

.particle-3 {
  left: 68%;
  width: 6px;
  height: 6px;
  background: #FCD34D;
  box-shadow: 0 0 12px #FCD34D, 0 0 20px rgba(252, 211, 77, 0.8);
  animation: riseAndDrift1 7.2s ease-in-out infinite 0.8s;
}

.particle-4 {
  left: 88%;
  width: 8px;
  height: 8px;
  background: #22D3EE;
  box-shadow: 0 0 16px #22D3EE, 0 0 26px rgba(34, 211, 238, 0.8);
  animation: riseAndDrift2 6.1s ease-in-out infinite 2.2s;
}

@keyframes riseAndDrift1 {
  0% {
    transform: translateY(0) translateX(0) scale(0.5);
    opacity: 0;
  }
  20% {
    opacity: 0.9;
  }
  50% {
    transform: translateY(-50vh) translateX(35px) scale(1.1);
    opacity: 1;
  }
  80% {
    opacity: 0.7;
  }
  100% {
    transform: translateY(-105vh) translateX(-25px) scale(0.4);
    opacity: 0;
  }
}

@keyframes riseAndDrift2 {
  0% {
    transform: translateY(0) translateX(0) scale(0.6);
    opacity: 0;
  }
  25% {
    opacity: 0.95;
  }
  55% {
    transform: translateY(-55vh) translateX(-40px) scale(1.2);
    opacity: 1;
  }
  85% {
    opacity: 0.6;
  }
  100% {
    transform: translateY(-105vh) translateX(30px) scale(0.4);
    opacity: 0;
  }
}

/* ==========================================================================
   Base Layout & Container
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

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

img, svg {
  display: block;
}

/* ==========================================================================
   Navigation Bar
   ========================================================================== */

.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 5, 36, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
}

.nav-container {
  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: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--text-main);
}

.brand-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 18px var(--primary-glow);
}

.brand-logo .logo-icon svg {
  width: 20px;
  height: 20px;
  fill: #0F0524;
}

.brand-logo span {
  background: linear-gradient(135deg, #FCD34D 10%, #22D3EE 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 10px rgba(252, 211, 77, 0.4));
}

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

.nav-menu a {
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
}

.nav-menu a:hover {
  color: var(--secondary);
  text-shadow: 0 0 10px rgba(34, 211, 238, 0.5);
}

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

/* ==========================================================================
   CTA Buttons: Yellow to Cyan Gradient + 12px Radius + Yellow/Cyan Glow Hover
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 24px;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: var(--radius-btn);
  cursor: pointer;
  white-space: nowrap;
  transition: var(--transition);
  text-align: center;
  min-height: 46px;
}

/* Primary CTA: Yellow to Cyan Gradient with 30px Yellow Glow, Turns Cyan on Hover */
.btn-primary {
  background: linear-gradient(135deg, #FCD34D 0%, #22D3EE 100%);
  color: #0F0524;
  border: none;
  box-shadow: 0 0 30px rgba(252, 211, 77, 0.6);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #FCD34D 0%, #22D3EE 100%);
  color: #0F0524;
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(34, 211, 238, 0.85);
}

.btn-outline {
  background: rgba(34, 211, 238, 0.08);
  color: #FFFFFF;
  border: 1px solid rgba(34, 211, 238, 0.35);
  border-radius: var(--radius-btn);
}

.btn-outline:hover {
  background: rgba(34, 211, 238, 0.16);
  border-color: #22D3EE;
  color: #FFFFFF;
  transform: translateY(-2px);
  box-shadow: 0 0 20px rgba(34, 211, 238, 0.4);
}

.btn-lg {
  padding: 15px 36px;
  font-size: 1.05rem;
  font-weight: 750;
  min-height: 50px;
}

.btn-block {
  width: 100%;
}

/* Badge Component */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 16px;
  border-radius: 9999px;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.badge-glow {
  background: rgba(252, 211, 77, 0.1);
  border: 1px solid rgba(252, 211, 77, 0.38);
  color: #FCD34D;
  box-shadow: 0 0 16px rgba(252, 211, 77, 0.2);
  margin-bottom: 20px;
}

.badge-glow .pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: #22D3EE;
  box-shadow: 0 0 10px #22D3EE;
}

/* ==========================================================================
   Section Common Styles
   ========================================================================== */

.section {
  padding: 85px 0;
  position: relative;
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 54px;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 2.3rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 14px;
  color: var(--text-main);
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.65;
}

/* ==========================================================================
   Hero Section Layout
   Left Column: H1 GLADOS + Intro + CTA + Stats
   Right Column: 340×340px 3D Photon Tunnel Animation
   ========================================================================== */

.hero-section {
  padding: 70px 0 60px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 48px;
}

.hero-left-col {
  text-align: left;
}

.hero-headline {
  margin-bottom: 24px;
}

/* H1「GLADOS」in Space Grotesk, Yellow to Cyan Gradient + Double Text Shadow */
.glados-brand-title {
  display: block;
  font-family: var(--font-heading);
  font-size: 4.8rem;
  font-weight: 700;
  line-height: 1.02;
  letter-spacing: -2px;
  background: linear-gradient(135deg, #FCD34D 0%, #22D3EE 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 18px rgba(252, 211, 77, 0.55)) drop-shadow(0 0 36px rgba(34, 211, 238, 0.45));
}

.hero-headline-sub {
  display: block;
  font-family: var(--font-heading);
  font-size: 1.85rem;
  font-weight: 700;
  color: #FFFFFF;
  margin-top: 10px;
  letter-spacing: -0.5px;
}

.hero-subheadline {
  font-size: 1.08rem;
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 34px;
  max-width: 620px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 44px;
  flex-wrap: wrap;
}

.trust-badges {
  display: flex;
  align-items: center;
  gap: 36px;
  padding-top: 28px;
  border-top: 1px solid var(--border-color);
  flex-wrap: wrap;
}

.trust-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.trust-num {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: #FCD34D;
  text-shadow: 0 0 14px rgba(252, 211, 77, 0.4);
}

.trust-desc {
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* ==========================================================================
   340×340px 3D Photon Tunnel Animation
   - 5 Depth Rings (300/240/180/120/60px, Yellow/Cyan Alternating + Glow Shadows)
   - 16s Y-axis 360° Rotation (3D Tunnel Perspective)
   - 3 Flying Photons (Yellow/Cyan, 2s Cycle Far to Near with Perspective Scale)
   - Center Photon Core (40px, Radial White->Yellow->Cyan, 2s Pulse Breathing)
   ========================================================================== */

.hero-right-col {
  display: flex;
  justify-content: center;
  align-items: center;
}

.photon-tunnel-viewport {
  width: 340px;
  height: 340px;
  position: relative;
  perspective: 900px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Rotator: 16s Y-axis 360° Continuous Rotation with Tilted Perspective */
.tunnel-rotator {
  width: 100%;
  height: 100%;
  position: absolute;
  transform-style: preserve-3d;
  animation: tunnelYRotation 16s linear infinite;
  display: flex;
  align-items: center;
  justify-content: center;
}

@keyframes tunnelYRotation {
  0% {
    transform: rotateX(16deg) rotateY(0deg);
  }
  100% {
    transform: rotateX(16deg) rotateY(360deg);
  }
}

/* 5 Concentric Rings with Glow Shadows */
.tunnel-ring {
  position: absolute;
  border-radius: 50%;
  border-style: solid;
  pointer-events: none;
}

/* Ring 1: 300px, Yellow, Z = 110px */
.ring-1 {
  width: 300px;
  height: 300px;
  border-width: 2.5px;
  border-color: #FCD34D;
  transform: translateZ(110px);
  box-shadow: 0 0 24px rgba(252, 211, 77, 0.7), inset 0 0 16px rgba(252, 211, 77, 0.4);
}

/* Ring 2: 240px, Cyan, Z = 55px */
.ring-2 {
  width: 240px;
  height: 240px;
  border-width: 2.2px;
  border-color: #22D3EE;
  transform: translateZ(55px);
  box-shadow: 0 0 20px rgba(34, 211, 238, 0.75), inset 0 0 14px rgba(34, 211, 238, 0.45);
}

/* Ring 3: 180px, Yellow, Z = 0px */
.ring-3 {
  width: 180px;
  height: 180px;
  border-width: 2px;
  border-color: #FCD34D;
  transform: translateZ(0px);
  box-shadow: 0 0 18px rgba(252, 211, 77, 0.7), inset 0 0 12px rgba(252, 211, 77, 0.4);
}

/* Ring 4: 120px, Cyan, Z = -55px */
.ring-4 {
  width: 120px;
  height: 120px;
  border-width: 1.8px;
  border-color: #22D3EE;
  transform: translateZ(-55px);
  box-shadow: 0 0 16px rgba(34, 211, 238, 0.8), inset 0 0 10px rgba(34, 211, 238, 0.5);
}

/* Ring 5: 60px, Yellow, Z = -110px */
.ring-5 {
  width: 60px;
  height: 60px;
  border-width: 1.8px;
  border-color: #FCD34D;
  transform: translateZ(-110px);
  box-shadow: 0 0 14px rgba(252, 211, 77, 0.85), inset 0 0 8px rgba(252, 211, 77, 0.6);
}

/* 3 Flying Glowing Photons (Far to Near, 2s Cycle, Scale Perspective) */
.traveling-photon {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}

.photon-yellow {
  width: 12px;
  height: 12px;
  background: #FCD34D;
  box-shadow: 0 0 18px #FCD34D, 0 0 32px rgba(252, 211, 77, 0.9);
  animation: photonTraverse 2s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

.photon-cyan {
  width: 13px;
  height: 13px;
  background: #22D3EE;
  box-shadow: 0 0 18px #22D3EE, 0 0 32px rgba(34, 211, 238, 0.9);
  animation: photonTraverse 2s cubic-bezier(0.4, 0, 0.2, 1) infinite 0.67s;
}

.photon-mixed {
  width: 11px;
  height: 11px;
  background: #FCD34D;
  box-shadow: 0 0 16px #22D3EE, 0 0 30px rgba(252, 211, 77, 0.9);
  animation: photonTraverse 2s cubic-bezier(0.4, 0, 0.2, 1) infinite 1.33s;
}

@keyframes photonTraverse {
  0% {
    transform: translateZ(-130px) scale(0.25);
    opacity: 0;
  }
  20% {
    opacity: 0.9;
  }
  80% {
    opacity: 1;
  }
  100% {
    transform: translateZ(145px) scale(2.4);
    opacity: 0;
  }
}

/* Center Photon Core (40px, Radial White->Yellow->Cyan, 2s Pulse Breathing) */
.photon-core {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  position: absolute;
  background: radial-gradient(circle, #FFFFFF 0%, #FCD34D 48%, #22D3EE 100%);
  animation: corePulse 2s ease-in-out infinite;
  z-index: 5;
}

@keyframes corePulse {
  0%, 100% {
    transform: scale(0.85);
    box-shadow: 0 0 20px rgba(252, 211, 77, 0.7), 0 0 36px rgba(34, 211, 238, 0.5);
  }
  50% {
    transform: scale(1.22);
    box-shadow: 0 0 32px rgba(252, 211, 77, 1), 0 0 60px rgba(34, 211, 238, 0.9);
  }
}

/* ==========================================================================
   Feature Cards (3 Core Advantages)
   ========================================================================== */

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, #22D3EE, transparent);
  opacity: 0;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-6px);
  background: var(--bg-card-hover);
  border-color: var(--border-color-hover);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.5), 0 0 24px rgba(34, 211, 238, 0.15);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon-wrapper {
  width: 58px;
  height: 58px;
  border-radius: var(--radius-md);
  background: rgba(34, 211, 238, 0.12);
  border: 1px solid rgba(34, 211, 238, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: #22D3EE;
}

.feature-icon-wrapper svg {
  width: 28px;
  height: 28px;
  fill: currentColor;
}

.feature-title {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}

.feature-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-top: 1px solid var(--border-color);
  padding-top: 16px;
}

.feature-list li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.feature-list li svg {
  width: 15px;
  height: 15px;
  fill: #FCD34D;
  flex-shrink: 0;
}

/* ==========================================================================
   Streaming & AI Support Section
   ========================================================================== */

.unlock-wrapper {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 44px 36px;
  position: relative;
  overflow: hidden;
}

.unlock-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 36px;
}

.unlock-box {
  background: rgba(15, 5, 36, 0.7);
  border: 1px solid rgba(34, 211, 238, 0.12);
  border-radius: var(--radius-md);
  padding: 28px 24px;
}

.unlock-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.unlock-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
}

.unlock-icon.ai {
  background: rgba(252, 211, 77, 0.15);
  color: #FCD34D;
}

.unlock-icon.media {
  background: rgba(34, 211, 238, 0.15);
  color: #22D3EE;
}

.unlock-icon svg {
  width: 22px;
  height: 22px;
  fill: currentColor;
}

.unlock-header h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
}

.unlock-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.tag-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-sm);
  padding: 7px 14px;
  font-size: 0.88rem;
  font-weight: 500;
  color: #e2e8f0;
}

.tag-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: #22D3EE;
  box-shadow: 0 0 8px #22D3EE;
}

.unlock-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   Pricing Section (Real GlaDos Plans)
   ========================================================================== */

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 38px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card.featured {
  background: rgba(38, 16, 77, 0.92);
  border-color: rgba(252, 211, 77, 0.55);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.5), 0 0 30px rgba(252, 211, 77, 0.2);
  transform: scale(1.03);
}

.pricing-card.featured:hover {
  transform: scale(1.05) translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.6), 0 0 35px rgba(252, 211, 77, 0.3);
}

.pricing-card:hover {
  border-color: var(--border-color-hover);
  transform: translateY(-4px);
}

.popular-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #FCD34D, #22D3EE);
  color: #0F0524;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 16px;
  border-radius: 9999px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.pricing-name {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.pricing-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.pricing-price {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
}

.currency {
  font-size: 1.4rem;
  font-weight: 700;
  color: #FCD34D;
}

.amount {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 700;
  line-height: 1;
  color: #FFFFFF;
}

.period {
  font-size: 0.9rem;
  color: var(--text-dim);
}

.pricing-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
  flex-grow: 1;
}

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

.pricing-features li svg {
  width: 16px;
  height: 16px;
  fill: #22D3EE;
  flex-shrink: 0;
}

/* ==========================================================================
   User Reviews Section
   ========================================================================== */

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-stars {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
  color: #FCD34D;
}

.review-stars svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.review-text {
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.65;
  margin-bottom: 22px;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid var(--border-color);
  padding-top: 16px;
}

.author-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(252, 211, 77, 0.2), rgba(34, 211, 238, 0.2));
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.95rem;
  color: #FCD34D;
  border: 1px solid rgba(252, 211, 77, 0.35);
}

.author-info h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}

.author-info p {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ==========================================================================
   6 FAQ Section (HTML5 Details / Summary)
   ========================================================================== */

.faq-wrapper {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  border-color: rgba(34, 211, 238, 0.4);
}

.faq-item[open] {
  border-color: #22D3EE;
  background: var(--bg-card-hover);
  box-shadow: 0 0 20px rgba(34, 211, 238, 0.15);
}

.faq-summary {
  padding: 20px 24px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  user-select: none;
  list-style: none;
}

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

.faq-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  transition: transform 0.25s ease;
  fill: #22D3EE;
}

.faq-item[open] .faq-icon {
  transform: rotate(180deg);
  fill: #FCD34D;
}

.faq-content {
  padding: 0 24px 22px;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ==========================================================================
   Call to Action Banner
   ========================================================================== */

.cta-banner {
  background: linear-gradient(135deg, rgba(38, 16, 77, 0.9) 0%, rgba(20, 8, 48, 0.95) 100%);
  border: 1px solid rgba(252, 211, 77, 0.35);
  border-radius: var(--radius-lg);
  padding: 56px 40px;
  text-align: center;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6), 0 0 35px rgba(252, 211, 77, 0.15);
  margin-top: 40px;
}

.cta-banner h2 {
  font-family: var(--font-heading);
  font-size: 2.3rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: #FFFFFF;
}

.cta-banner p {
  color: var(--text-muted);
  font-size: 1.1rem;
  max-width: 620px;
  margin: 0 auto 32px;
}

/* ==========================================================================
   Footer Section - Strictly 4 Links
   ========================================================================== */

.footer {
  border-top: 1px solid var(--border-color);
  padding: 50px 0 36px;
  background-color: #0a0319;
  margin-top: 60px;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-nav a {
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 500;
  transition: var(--transition);
  padding: 6px 10px;
}

.footer-nav a:hover {
  color: #22D3EE;
  text-decoration: underline;
  text-underline-offset: 6px;
  text-shadow: 0 0 10px rgba(34, 211, 238, 0.6);
}

.footer-copyright {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.85rem;
}

/* ==========================================================================
   Standalone Subpage Layout
   ========================================================================== */

.subpage-container {
  max-width: 860px;
  margin: 40px auto 80px;
  padding: 0 20px;
}

.subpage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

.subpage-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 24px;
  margin-bottom: 36px;
}

.subpage-title {
  font-family: var(--font-heading);
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #FFFFFF;
}

.subpage-update {
  font-size: 0.88rem;
  color: var(--text-dim);
}

.subpage-body {
  color: rgba(255, 255, 255, 0.85);
  font-size: 1rem;
  line-height: 1.8;
}

.subpage-body h2 {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  color: #FCD34D;
  margin: 32px 0 14px;
}

.subpage-body h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: #22D3EE;
  margin: 20px 0 10px;
}

.subpage-body p {
  margin-bottom: 16px;
}

.subpage-body ul {
  margin-bottom: 20px;
  padding-left: 24px;
}

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

.subpage-body strong {
  color: #FFFFFF;
}

.notice-box {
  background: rgba(34, 211, 238, 0.08);
  border-left: 4px solid #22D3EE;
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
  color: #22D3EE;
  font-size: 0.95rem;
}

.notice-box.danger {
  background: rgba(239, 68, 68, 0.08);
  border-left-color: #ef4444;
  color: #fca5a5;
}

/* ==========================================================================
   Responsive Media Queries (@media)
   Strict Mobile Adaptations: Single Column, Large Touch Targets
   ========================================================================== */

@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 40px;
  }

  .hero-left-col {
    text-align: center;
  }

  .hero-subheadline {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-cta-group {
    justify-content: center;
  }

  .trust-badges {
    justify-content: center;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .unlock-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 520px;
    margin: 0 auto;
    gap: 28px;
  }

  .pricing-card.featured {
    transform: none;
  }

  .pricing-card.featured:hover {
    transform: translateY(-4px);
  }
  
  .reviews-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

@media (max-width: 768px) {
  .section {
    padding: 60px 0;
    overflow-x: hidden;
  }

  .navbar {
    padding: 12px 0;
    width: 100%;
  }

  .nav-container {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .nav-menu {
    display: none !important;
  }

  .brand-logo {
    flex-shrink: 0;
  }

  .nav-actions {
    flex-shrink: 0;
  }

  .hero-section {
    padding: 50px 0 40px;
  }

  .glados-brand-title {
    font-size: 3.6rem;
  }

  .hero-headline-sub {
    font-size: 1.4rem;
  }

  .hero-cta-group {
    flex-direction: column;
    gap: 14px;
    width: 100%;
  }

  .hero-cta-group .btn {
    width: 100%;
    min-height: 50px;
    font-size: 1.05rem;
  }

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

  .photon-tunnel-viewport {
    width: 280px;
    height: 280px;
  }

  .ring-1 { width: 250px; height: 250px; }
  .ring-2 { width: 200px; height: 200px; }
  .ring-3 { width: 150px; height: 150px; }
  .ring-4 { width: 100px; height: 100px; }
  .ring-5 { width: 50px; height: 50px; }

  .unlock-wrapper {
    padding: 28px 18px;
  }

  .pricing-card {
    padding: 30px 20px;
  }

  .cta-banner {
    padding: 38px 20px;
  }

  .cta-banner h2 {
    font-size: 1.8rem;
  }

  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }

  .subpage-card {
    padding: 26px 18px;
  }

  .subpage-title {
    font-size: 1.8rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .nav-container {
    gap: 12px;
  }

  .nav-actions .btn {
    padding: 8px 16px;
    font-size: 0.88rem;
    white-space: nowrap;
    min-height: 44px;
  }

  .brand-logo {
    font-size: 1.25rem;
    gap: 8px;
  }

  .brand-logo .logo-icon {
    width: 30px;
    height: 30px;
  }

  .glados-brand-title {
    font-size: 2.6rem;
  }

  .hero-headline-sub {
    font-size: 1.15rem;
  }

  .hero-subheadline {
    font-size: 0.95rem;
    line-height: 1.65;
  }

  .section-title {
    font-size: 1.7rem;
  }

  .trust-badges {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    width: 100%;
    text-align: center;
  }

  .photon-tunnel-viewport {
    width: 250px;
    height: 250px;
    max-width: 100%;
  }

  .ring-1 { width: 230px; height: 230px; }
  .ring-2 { width: 180px; height: 180px; }
  .ring-3 { width: 135px; height: 135px; }
  .ring-4 { width: 90px; height: 90px; }
  .ring-5 { width: 45px; height: 45px; }
}


/* ==========================================================================
   SEO Knowledge Base & Article Cards Styling
   ========================================================================== */

.seo-toc {
  background: rgba(20, 8, 48, 0.85);
  border: 1px solid rgba(34, 211, 238, 0.25);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 40px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}

.seo-toc-title {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  color: #FCD34D;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.seo-toc-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

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

.seo-toc-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  color: #cbd5e1;
  font-size: 0.9rem;
  transition: var(--transition);
}

.seo-toc-link:hover {
  background: rgba(34, 211, 238, 0.1);
  border-color: rgba(34, 211, 238, 0.4);
  color: #22D3EE;
  transform: translateX(4px);
}

.seo-toc-num {
  font-family: var(--font-heading);
  font-weight: 700;
  color: #FCD34D;
  font-size: 0.85rem;
}

.seo-article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 42px 36px;
  margin-bottom: 48px;
  position: relative;
  transition: var(--transition);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}

.seo-article-card:hover {
  border-color: rgba(34, 211, 238, 0.35);
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.5), 0 0 24px rgba(34, 211, 238, 0.1);
}

.seo-article-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 18px;
  margin-bottom: 24px;
}

.seo-article-title {
  font-family: var(--font-heading);
  font-size: 1.65rem;
  font-weight: 700;
  line-height: 1.35;
  color: #FFFFFF;
  margin-bottom: 12px;
}

.seo-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.seo-meta-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.seo-tag {
  background: rgba(252, 211, 77, 0.1);
  color: #FCD34D;
  border: 1px solid rgba(252, 211, 77, 0.3);
  padding: 2px 10px;
  border-radius: 9999px;
  font-size: 0.78rem;
  font-weight: 600;
}

.seo-tag.cyan {
  background: rgba(34, 211, 238, 0.1);
  color: #22D3EE;
  border-color: rgba(34, 211, 238, 0.3);
}

.seo-internal-link {
  color: #22D3EE;
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 4px;
  transition: var(--transition);
}

.seo-internal-link:hover {
  color: #FCD34D;
  text-shadow: 0 0 8px rgba(252, 211, 77, 0.6);
}

.seo-cta-inline {
  margin: 28px 0 16px;
  background: linear-gradient(135deg, rgba(38, 16, 77, 0.75), rgba(20, 8, 48, 0.85));
  border: 1px dashed rgba(252, 211, 77, 0.35);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.seo-cta-text {
  font-size: 0.95rem;
  color: #FFFFFF;
}

.seo-cta-text strong {
  color: #FCD34D;
}


/* Accessibility & Skip Link */
.skip-link {
  position: absolute;
  top: -9999px;
  left: 20px;
  z-index: 999999;
  background: #FCD34D;
  color: #0F0524;
  padding: 12px 20px;
  font-weight: 700;
  border-radius: 8px;
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
  transition: top 0.2s ease-in-out;
}
.skip-link:focus {
  top: 20px;
  outline: 3px solid #22D3EE;
}

/* Clear Focus Indicators for Keyboard Users */
:focus-visible {
  outline: 2px solid #FCD34D;
  outline-offset: 3px;
}

/* Fixed Header Anchor Offset Prevention */
section[id], article[id], .subpage-card[id], .seo-article-card[id] {
  scroll-margin-top: calc(72px + 24px);
}

/* Mobile Touch Target Standards (Min 44x44 CSS px) */
.btn, .nav-actions a, .seo-toc-link, .faq-summary {
  min-height: 44px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* Text Wrapping Guard against Container Breaking */
body, h1, h2, h3, p, .pricing-card, .seo-article-card {
  overflow-wrap: break-word;
  word-break: break-word;
}

/* Screen Reader Only Utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Pricing Parameter Comparison Table (Semantic & Responsive) */
.pricing-table-container {
  margin-top: 48px;
  overflow-x: auto;
  max-width: 100%;
  width: 100%;
  display: block;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.3);
}

.pricing-comparison-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 680px;
}

.pricing-comparison-table caption {
  padding: 18px 24px;
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  color: #FCD34D;
  text-align: left;
  background: rgba(15, 5, 36, 0.65);
  border-bottom: 1px solid var(--border-color);
}

.pricing-comparison-table th,
.pricing-comparison-table td {
  padding: 16px 22px;
  border-bottom: 1px solid rgba(34, 211, 238, 0.12);
  font-size: 0.95rem;
  vertical-align: middle;
}

.pricing-comparison-table thead th {
  background: rgba(34, 211, 238, 0.08);
  color: #22D3EE;
  font-weight: 600;
  font-size: 0.98rem;
}

.pricing-comparison-table tbody th {
  color: #FFFFFF;
  font-weight: 500;
}

.pricing-comparison-table td {
  color: var(--text-muted);
}

.pricing-comparison-table tbody tr:hover td {
  background: rgba(255, 255, 255, 0.02);
  color: #FFFFFF;
}

/* Reduced Motion Preference Compliance */
@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;
  }
  .photon-beam, .quantum-particle, .tunnel-stage, .photon-traveler, .core-pulse {
    animation: none !important;
  }
}