:root {
  --bg-main: #020617; /* 深冰夜 */
  --bg-card: rgba(15, 23, 42, 0.8);
  --bg-card-hover: rgba(22, 33, 62, 0.9);
  --border-color: rgba(34, 211, 238, 0.16);
  --border-focus: rgba(34, 211, 238, 0.5);
  --primary: #22D3EE; /* 冰晶青 */
  --secondary: #A5F3FC; /* 雪光青 */
  --primary-hover: #A5F3FC;
  --accent: #22D3EE;
  --accent-gradient: linear-gradient(135deg, #22D3EE 0%, #A5F3FC 100%);
  --accent-gold: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  --text-main: #FFFFFF;
  --text-muted: rgba(255, 255, 255, 0.68);
  --text-sub: rgba(255, 255, 255, 0.55); /* 对比度提升至 > 4.5:1 */
  --success: #22D3EE;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --shadow: 0 10px 30px -10px rgba(2, 6, 23, 0.85);
  --shadow-glow: 0 0 25px rgba(34, 211, 238, 0.25);
  --font-title: 'Space Grotesk', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

/* 键盘访问“跳转到主要内容”入口 */
.skip-link {
  position: absolute;
  top: -120px;
  left: 16px;
  background: var(--accent-gradient);
  color: #020617;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.95rem;
  z-index: 99999;
  text-decoration: none;
  box-shadow: 0 0 25px rgba(34, 211, 238, 0.6);
  transition: top 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.skip-link:focus,
.skip-link:focus-visible {
  top: 16px;
  outline: 2px solid #ffffff;
  outline-offset: 2px;
}

/* 全局键盘导航高对比度清晰焦点状态 */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
}

/* 固定页眉防遮挡锚点滚动偏移 */
section[id],
article[id],
div[id],
.features-section,
.unlock-section,
.pricing-section,
.reviews-section,
.faq-section {
  scroll-margin-top: 88px;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-color: #020617;
  background-image: 
    radial-gradient(circle at 18% 15%, rgba(34, 211, 238, 0.15) 0%, transparent 45%),
    radial-gradient(circle at 82% 25%, rgba(165, 243, 252, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 50% 75%, rgba(34, 211, 238, 0.08) 0%, transparent 55%);
  background-attachment: fixed;
  position: relative;
}

body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(to right, rgba(34, 211, 238, 0.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(34, 211, 238, 0.045) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse at 50% 45%, black 25%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 45%, black 25%, transparent 75%);
  pointer-events: none;
  z-index: 0;
}

/* ==========================================================
   Background Animation: Ice Crystal Matrix & Falling Particles
   ========================================================== */
.ice-bg-layer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.bg-fine-grid {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(to right, rgba(34, 211, 238, 0.05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(34, 211, 238, 0.05) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse at 50% 45%, black 25%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 45%, black 25%, transparent 75%);
}

/* 8 Pulsing Hexagons (Alternating Cyan & Snow Cyan, 4s cycle) */
.ice-hex {
  position: absolute;
  width: 32px;
  height: 32px;
  animation: hexPulse 4s ease-in-out infinite;
}

@keyframes hexPulse {
  0%, 100% {
    opacity: 0.2;
    transform: scale(0.85) rotate(0deg);
    filter: drop-shadow(0 0 3px currentColor);
  }
  50% {
    opacity: 0.85;
    transform: scale(1.15) rotate(15deg);
    filter: drop-shadow(0 0 14px currentColor);
  }
}

.hex-1 { top: 7%; left: 5%; color: #22D3EE; animation-delay: 0s; }
.hex-2 { top: 16%; right: 7%; color: #A5F3FC; animation-delay: 0.5s; }
.hex-3 { top: 36%; left: 8%; color: #22D3EE; animation-delay: 1.0s; }
.hex-4 { top: 48%; right: 9%; color: #A5F3FC; animation-delay: 1.5s; }
.hex-5 { top: 62%; left: 6%; color: #22D3EE; animation-delay: 2.0s; }
.hex-6 { top: 72%; right: 12%; color: #A5F3FC; animation-delay: 2.5s; }
.hex-7 { top: 84%; left: 14%; color: #22D3EE; animation-delay: 3.0s; }
.hex-8 { top: 93%; right: 6%; color: #A5F3FC; animation-delay: 3.5s; }

/* 4 Drifting & Falling Particles */
.ice-particle {
  position: absolute;
  top: -40px;
  border-radius: 50%;
  pointer-events: none;
  animation: fallingIce 14s linear infinite;
}

@keyframes fallingIce {
  0% {
    transform: translate3d(0, -40px, 0) rotate(0deg);
    opacity: 0;
  }
  12% {
    opacity: 0.85;
  }
  50% {
    transform: translate3d(45px, 50vh, 0) rotate(180deg);
  }
  88% {
    opacity: 0.85;
  }
  100% {
    transform: translate3d(-30px, 105vh, 0) rotate(360deg);
    opacity: 0;
  }
}

.part-1 { left: 16%; width: 6px; height: 6px; background: #22D3EE; box-shadow: 0 0 12px #22D3EE; animation-duration: 12s; animation-delay: 0s; }
.part-2 { left: 38%; width: 8px; height: 8px; background: #A5F3FC; box-shadow: 0 0 15px #A5F3FC; animation-duration: 16s; animation-delay: 3.5s; }
.part-3 { left: 65%; width: 7px; height: 7px; background: #22D3EE; box-shadow: 0 0 14px #22D3EE; animation-duration: 14s; animation-delay: 7s; }
.part-4 { left: 84%; width: 5px; height: 5px; background: #A5F3FC; box-shadow: 0 0 10px #A5F3FC; animation-duration: 18s; animation-delay: 10.5s; }

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* Header & Navigation */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background-color: rgba(2, 6, 23, 0.85);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.brand-logo .logo-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 4px 12px rgba(56, 189, 248, 0.35);
}

.brand-logo .logo-icon svg {
  width: 22px;
  height: 22px;
  stroke: currentColor;
  stroke-width: 2;
  fill: none;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-links a:hover {
  color: var(--primary);
}

/* Base Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  min-height: 48px;
  touch-action: manipulation;
}

.btn-primary {
  background: linear-gradient(135deg, #22D3EE 0%, #A5F3FC 100%);
  color: #020617; /* 深色文字 */
  font-weight: 700;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 0 30px rgba(34, 211, 238, 0.45);
  letter-spacing: 0.2px;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 35px rgba(165, 243, 252, 0.7);
  filter: brightness(1.06);
}

.btn-secondary {
  background: rgba(15, 23, 42, 0.65);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-radius: 12px;
}

.btn-secondary:hover {
  background: rgba(30, 41, 59, 0.85);
  border-color: rgba(34, 211, 238, 0.4);
  color: #fff;
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.9rem;
  min-height: 44px;
}

.btn-block {
  width: 100%;
}

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

.hero-brand-layout {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 36px;
  max-width: 1100px;
  margin: 0 auto 36px;
  text-align: left;
}

.hero-brand-left {
  flex: 1;
  min-width: 320px;
}

.hero-brand-right {
  flex-shrink: 0;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 999px;
  background: rgba(34, 211, 238, 0.1);
  border: 1px solid rgba(34, 211, 238, 0.3);
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 20px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--primary);
  box-shadow: 0 0 10px var(--primary);
}

.hero-title {
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(2.4rem, 4.6vw, 3.8rem);
  line-height: 1.15;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #22D3EE 0%, #A5F3FC 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 16px rgba(34, 211, 238, 0.6)) drop-shadow(0 0 35px rgba(165, 243, 252, 0.35));
}

.hero-title-en {
  font-size: 0.85em;
  font-weight: 700;
}

.hero-subtitle-line {
  font-size: 0.52em;
  font-weight: 600;
  display: block;
  color: #FFFFFF;
  -webkit-text-fill-color: #FFFFFF;
  filter: none;
  margin-top: 8px;
  letter-spacing: 0;
}

.hero-lead-text {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.65;
  margin-bottom: 20px;
}

/* 340×340px 4-Layer Hexagon Ice Crystal Matrix SVG */
.ice-matrix-wrapper {
  width: 340px;
  height: 340px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ice-matrix-svg {
  width: 340px;
  height: 340px;
  overflow: visible;
}

/* 2 Reverse Rotating Dashed Orbit Circles */
.orbit-circle {
  transform-origin: 170px 170px;
}

.orbit-1 {
  animation: orbitSpin 20s linear infinite;
}

.orbit-2 {
  animation: orbitSpin 24s linear infinite reverse;
}

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

/* Hexagon Matrix Group in 3D Y+Z Simultaneous Rotation (20s) with Dual Glow */
.matrix-hex-group {
  transform-origin: 170px 170px;
  animation: matrix3DRotate 20s linear infinite;
  filter: drop-shadow(0 0 15px rgba(34, 211, 238, 0.75)) drop-shadow(0 0 30px rgba(165, 243, 252, 0.45));
}

@keyframes matrix3DRotate {
  0% {
    transform: perspective(850px) rotateY(0deg) rotateZ(0deg);
  }
  100% {
    transform: perspective(850px) rotateY(360deg) rotateZ(360deg);
  }
}

/* 4 Nested Hexagon Opacity Pulse */
.hex-outer {
  animation: hexPulseOpacity1 4s ease-in-out infinite;
}

.hex-mid {
  animation: hexPulseOpacity2 4s ease-in-out infinite 1s;
}

.hex-inner {
  animation: hexPulseOpacity3 4s ease-in-out infinite 2s;
}

.hex-center {
  animation: hexPulseOpacity4 4s ease-in-out infinite 3s;
}

@keyframes hexPulseOpacity1 {
  0%, 100% { opacity: 0.55; }
  50% { opacity: 0.95; }
}

@keyframes hexPulseOpacity2 {
  0%, 100% { opacity: 0.9; }
  50% { opacity: 0.4; }
}

@keyframes hexPulseOpacity3 {
  0%, 100% { opacity: 0.45; }
  50% { opacity: 0.95; }
}

@keyframes hexPulseOpacity4 {
  0%, 100% { opacity: 0.95; }
  50% { opacity: 0.5; }
}

.node-glow {
  filter: drop-shadow(0 0 6px currentColor);
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 36px;
  font-weight: 400;
  line-height: 1.7;
}

.hero-intro-card {
  max-width: 860px;
  margin: 0 auto 36px;
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid rgba(34, 211, 238, 0.22);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  text-align: left;
  box-shadow: 0 10px 30px -10px rgba(2, 6, 23, 0.6);
}

.intro-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.hero-intro-card p {
  color: rgba(255, 255, 255, 0.85);
  font-size: 1rem;
  line-height: 1.75;
  margin: 0;
}

.plan-cycle-options {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 10px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.plan-cycle-tag {
  background: rgba(255, 255, 255, 0.06);
  padding: 2px 8px;
  border-radius: 4px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.75rem;
  color: #e2e8f0;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 860px;
  margin: 0 auto;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow);
}

.stat-item {
  text-align: center;
}

.stat-val {
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--primary);
  display: block;
  line-height: 1.2;
}

.stat-lbl {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Section Header Helper */
.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 50px;
}

.section-tag {
  display: inline-block;
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.3rem);
  font-weight: 700;
  margin-bottom: 14px;
  color: #fff;
  letter-spacing: -0.02em;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-muted);
}

/* Feature Section (3 Cards) */
.features-section {
  padding: 80px 0;
}

.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-md);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-focus);
  box-shadow: var(--shadow-glow);
}

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

.feature-icon-wrapper {
  width: 58px;
  height: 58px;
  border-radius: 14px;
  background: rgba(56, 189, 248, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  margin-bottom: 24px;
}

.feature-icon-wrapper svg {
  width: 28px;
  height: 28px;
  stroke: currentColor;
  stroke-width: 2;
  fill: none;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #fff;
}

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

.feature-points {
  list-style: none;
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feature-points li {
  font-size: 0.88rem;
  color: #cbd5e1;
  display: flex;
  align-items: center;
  gap: 8px;
}

.feature-points li svg {
  width: 16px;
  height: 16px;
  color: var(--success);
  flex-shrink: 0;
  stroke-width: 2.5;
}

/* Streaming & AI Section */
.unlock-section {
  padding: 80px 0;
  background: rgba(255, 255, 255, 0.015);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

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

.unlock-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.unlock-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.unlock-icon-badge {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(99, 102, 241, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}

.unlock-icon-badge svg {
  width: 24px;
  height: 24px;
}

.unlock-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: #fff;
}

.unlock-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 24px;
}

.platform-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.platform-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  color: #e2e8f0;
}

.platform-tag svg {
  width: 16px;
  height: 16px;
}

/* Pricing Section */
.pricing-section {
  padding: 80px 0;
}

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

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.pricing-card.featured {
  background: linear-gradient(180deg, rgba(28, 38, 60, 0.95) 0%, rgba(18, 24, 38, 0.95) 100%);
  border: 2px solid var(--primary);
  box-shadow: 0 10px 40px -10px rgba(56, 189, 248, 0.3);
  transform: translateY(-8px);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-gradient);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  white-space: nowrap;
}

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

.plan-name {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 6px;
}

.plan-tagline {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.plan-price-wrapper {
  margin-top: 18px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.plan-currency {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--primary);
}

.plan-price {
  font-size: 2.7rem;
  font-weight: 800;
  color: #fff;
  line-height: 1;
}

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

.plan-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 32px;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: #cbd5e1;
}

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

/* Reviews Section */
.reviews-section {
  padding: 80px 0;
  background: rgba(255, 255, 255, 0.015);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.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-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-stars {
  color: #f59e0b;
  display: flex;
  gap: 3px;
  margin-bottom: 16px;
}

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

.review-text {
  font-size: 0.94rem;
  color: #cbd5e1;
  line-height: 1.65;
  margin-bottom: 22px;
  flex-grow: 1;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 14px;
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  color: #fff;
}

.user-info h3,
.user-info h4 {
  font-size: 0.92rem;
  font-weight: 600;
  color: #fff;
}

.user-info span {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* FAQ Section */
.faq-section {
  padding: 80px 0;
}

.faq-list {
  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: border-color 0.2s ease;
}

.faq-item:hover {
  border-color: rgba(56, 189, 248, 0.3);
}

.faq-question {
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  list-style: none;
  user-select: none;
}

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

.faq-icon {
  width: 20px;
  height: 20px;
  stroke: var(--primary);
  stroke-width: 2;
  fill: none;
  transition: transform 0.25s ease;
  flex-shrink: 0;
  margin-left: 12px;
}

details[open] .faq-icon {
  transform: rotate(180deg);
}

details[open] .faq-question {
  color: var(--primary);
  border-bottom: 1px solid var(--border-color);
}

.faq-answer {
  padding: 20px 24px;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* Bottom CTA Banner */
.cta-banner {
  margin: 40px auto 80px;
  padding: 56px 40px;
  background: linear-gradient(135deg, rgba(34, 211, 238, 0.14) 0%, rgba(165, 243, 252, 0.08) 100%);
  border: 1px solid rgba(34, 211, 238, 0.35);
  border-radius: var(--radius-lg);
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 0 30px rgba(34, 211, 238, 0.12);
}

.cta-banner h2 {
  font-family: var(--font-title);
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
  font-weight: 700;
  margin-bottom: 14px;
  color: #fff;
}

.cta-banner p {
  color: var(--text-muted);
  max-width: 580px;
  margin: 0 auto 30px;
  font-size: 1.05rem;
}

/* Footer Section */
.footer {
  margin-top: auto;
  background: #01040f;
  border-top: 1px solid var(--border-color);
  padding: 50px 0 35px;
  position: relative;
  z-index: 1;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
}

/* Footer nav retaining ONLY the 4 required titles */
.footer-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  flex-wrap: wrap;
}

.footer-link-item {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s ease;
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 4px 8px;
}

.footer-link-item:hover {
  color: var(--primary);
}

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

/* Sub-page Specific Styles (About, Terms, Privacy, Sitemap) */
.subpage-container {
  max-width: 860px;
  margin: 60px auto 80px;
  padding: 0 24px;
}

.subpage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 44px;
  box-shadow: var(--shadow);
}

.subpage-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 24px;
  margin-bottom: 32px;
}

.subpage-title {
  font-size: 2.2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 8px;
}

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

.subpage-body h2 {
  font-size: 1.45rem;
  font-weight: 600;
  color: #f1f5f9;
  margin: 32px 0 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.subpage-body h2::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 18px;
  background: var(--primary);
  border-radius: 2px;
}

.subpage-body p {
  color: #cbd5e1;
  font-size: 0.98rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.subpage-body ul {
  margin: 12px 0 20px 24px;
  color: #cbd5e1;
  line-height: 1.8;
}

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

.info-alert {
  background: rgba(56, 189, 248, 0.08);
  border-left: 4px solid var(--primary);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 20px 0;
  color: #e2e8f0;
}

.warn-alert {
  background: rgba(239, 68, 68, 0.08);
  border-left: 4px solid #ef4444;
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 20px 0;
  color: #fca5a5;
}

/* Sitemap List Styles */
.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 24px;
}

.sitemap-group {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 24px;
}

.sitemap-group h2,
.sitemap-group h3 {
  font-size: 1.15rem;
  color: var(--primary);
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
}

.sitemap-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.sitemap-links a {
  color: #cbd5e1;
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s ease;
  display: flex;
  align-items: center;
  gap: 8px;
}

.sitemap-links a:hover {
  color: var(--primary);
}

/* ==========================================================
   Responsive Media Queries (@media)
   Optimized for seamless Mobile Single-Column Layout & Touch
   ========================================================== */
/* Article Directory Cards (Knowledge Base) */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 28px 0;
}

.article-card {
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
  text-decoration: none;
  color: inherit;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-focus);
  background: rgba(255, 255, 255, 0.045);
  box-shadow: 0 10px 25px -10px rgba(56, 189, 248, 0.2);
}

.article-card.featured-article {
  border-color: rgba(56, 189, 248, 0.35);
  background: linear-gradient(180deg, rgba(56, 189, 248, 0.06) 0%, rgba(18, 24, 38, 0.4) 100%);
}

.article-card-tag {
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.12);
  color: var(--primary);
  border: 1px solid rgba(56, 189, 248, 0.25);
  margin-bottom: 12px;
}

.article-card-title {
  font-size: 1.08rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.45;
  margin-bottom: 10px;
}

.article-card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 16px;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-sub);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 10px;
}

.article-read-more {
  color: var(--primary);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

@media (max-width: 992px) {
  .hero-brand-layout {
    flex-direction: column-reverse;
    text-align: center;
    gap: 28px;
  }

  .hero-brand-left {
    min-width: unset;
  }

  .features-grid,
  .pricing-grid,
  .reviews-grid,
  .article-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

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

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }
}

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

  .ice-matrix-wrapper {
    width: 270px;
    height: 270px;
  }

  .ice-matrix-svg {
    width: 270px;
    height: 270px;
  }

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

  .hero-title {
    font-size: 2rem;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .hero-stats {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 18px;
  }

  .features-grid,
  .unlock-grid,
  .pricing-grid,
  .reviews-grid,
  .sitemap-grid,
  .article-grid {
    grid-template-columns: 1fr;
  }

  .feature-card,
  .unlock-card,
  .pricing-card,
  .review-card,
  .subpage-card {
    padding: 24px 20px;
  }

  .cta-banner {
    padding: 36px 20px;
    margin: 30px auto 60px;
  }

  .footer-links {
    flex-direction: column;
    gap: 18px;
  }

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

/* ==========================================================
   无障碍规范：遵循系统偏好减少动效 (prefers-reduced-motion)
   ========================================================== */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto !important;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .matrix-hex-group,
  .orbit-circle,
  .ice-particle,
  .ice-hex,
  .node-glow,
  .badge-dot {
    animation: none !important;
  }
}