/* 高速VPN (GaoSu VPN) - 官方网站核心样式表
   风格: 超音速数据轨道 + 高端轻科技 SaaS
   主背景: 冷调珍珠白 (#F5F7F9)
   主色: 电光蓝 (#397BFF) + 荧光青 (#36E2D0) + 深石墨黑
*/

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700;900&family=Outfit:wght@400;600;700;800;900&display=swap');

:root {
  --bg-main: #F5F7F9;
  --bg-dark: #0A0E1A;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-card-dark: rgba(15, 22, 40, 0.85);
  --bg-alt: rgba(245, 247, 249, 0.95);

  --color-primary: #397BFF;
  --color-primary-dark: #1A5CE8;
  --color-primary-light: #EBF1FF;
  --color-cyan: #36E2D0;
  --color-cyan-dark: #1CB8A8;
  --color-cyan-light: #E0FAF7;
  --color-graphite: #111827;
  --color-graphite-mid: #1E2D45;

  --text-main: #111827;
  --text-muted: #4B6080;
  --text-light: #8FA0B8;
  --text-white: #FFFFFF;

  --border-light: rgba(57, 123, 255, 0.12);
  --border-hover: rgba(57, 123, 255, 0.45);
  --border-cyan: rgba(54, 226, 208, 0.35);

  --shadow-card: 0 8px 32px rgba(57, 123, 255, 0.10);
  --shadow-hover: 0 20px 50px rgba(57, 123, 255, 0.22);
  --shadow-glow-blue: 0 0 30px rgba(57, 123, 255, 0.45);
  --shadow-glow-cyan: 0 0 25px rgba(54, 226, 208, 0.4);

  --radius-xl: 32px;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 8px;

  --font-main: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
  --font-heading: 'Outfit', 'Noto Sans SC', sans-serif;

  --transition-bounce: all 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
  --transition-smooth: all 0.3s ease;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.75;
  overflow-x: hidden;
  position: relative;
}

/* 全局细线网格背景 */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(57, 123, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57, 123, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

/* 浮动光晕装饰 */
body::after {
  content: '';
  position: fixed;
  top: -200px;
  right: -200px;
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(57, 123, 255, 0.08) 0%, transparent 65%);
  pointer-events: none;
  z-index: 0;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: var(--transition-smooth);
}
a:hover { color: var(--color-primary-dark); }

ul { list-style: none; }

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

/* ===== HEADER / NAV ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: rgba(245, 247, 249, 0.88);
  border-bottom: 1px solid var(--border-light);
  transition: var(--transition-smooth);
}

.header.scrolled {
  box-shadow: 0 4px 24px rgba(57, 123, 255, 0.10);
  background: rgba(245, 247, 249, 0.96);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-heading);
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
}

.logo-icon {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, #397BFF 0%, #36E2D0 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 900;
  color: #FFFFFF;
  box-shadow: 0 4px 14px rgba(57, 123, 255, 0.35);
  position: relative;
  overflow: hidden;
}
.logo-icon::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(60deg, transparent, rgba(255,255,255,0.2), transparent);
  animation: logo-shine 3s infinite;
}
@keyframes logo-shine {
  0% { transform: translateX(-100%) rotate(30deg); }
  30% { transform: translateX(100%) rotate(30deg); }
  100% { transform: translateX(100%) rotate(30deg); }
}

.logo-text span {
  color: var(--color-primary);
  background: linear-gradient(135deg, #397BFF, #36E2D0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.nav-link {
  font-weight: 500;
  color: var(--text-muted);
  font-size: 0.97rem;
  position: relative;
  padding: 6px 0;
  transition: var(--transition-smooth);
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-cyan));
  border-radius: 2px;
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

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

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

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  color: var(--text-main);
  cursor: pointer;
  padding: 4px;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 1rem;
  font-weight: 700;
  border-radius: 50px;
  cursor: pointer;
  transition: var(--transition-bounce);
  text-decoration: none;
  border: none;
  outline: none;
  font-family: var(--font-main);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, #397BFF 0%, #1A5CE8 100%);
  color: #FFFFFF;
  box-shadow: 0 6px 20px rgba(57, 123, 255, 0.40);
}
.btn-primary:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 12px 32px rgba(57, 123, 255, 0.55);
  color: #FFFFFF;
}

.btn-cyan {
  background: linear-gradient(135deg, #36E2D0 0%, #1CB8A8 100%);
  color: #0A0E1A;
  box-shadow: 0 6px 20px rgba(54, 226, 208, 0.40);
}
.btn-cyan:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: var(--shadow-glow-cyan);
  color: #0A0E1A;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.95);
  color: var(--text-main);
  border: 1.5px solid var(--border-light);
  box-shadow: 0 4px 14px rgba(57, 123, 255, 0.08);
}
.btn-secondary:hover {
  background: #FFFFFF;
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-2px);
}

.btn-white {
  background: #FFFFFF;
  color: var(--color-primary);
  font-weight: 700;
}
.btn-white:hover {
  background: rgba(255,255,255,0.9);
  transform: translateY(-2px);
  color: var(--color-primary-dark);
}

.btn-glow {
  position: relative;
  overflow: hidden;
}
.btn-glow::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(60deg, transparent, rgba(255, 255, 255, 0.30), transparent);
  transform: rotate(30deg);
  animation: shine 4s infinite;
}
@keyframes shine {
  0% { transform: translateX(-100%) rotate(30deg); }
  25% { transform: translateX(100%) rotate(30deg); }
  100% { transform: translateX(100%) rotate(30deg); }
}

/* ===== BADGE PILL ===== */
.badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 18px;
  background: rgba(57, 123, 255, 0.08);
  border: 1px solid rgba(57, 123, 255, 0.20);
  border-radius: 30px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 22px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  background: var(--color-cyan);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--color-cyan);
  position: relative;
  flex-shrink: 0;
}
.badge-dot::after {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: 50%;
  background: var(--color-cyan);
  opacity: 0.35;
  animation: pulse-dot 2s infinite;
}
@keyframes pulse-dot {
  0% { transform: scale(1); opacity: 0.5; }
  60% { transform: scale(2); opacity: 0; }
  100% { transform: scale(1); opacity: 0; }
}

/* ===== HERO SECTION ===== */
.hero {
  padding: 80px 0 100px;
  position: relative;
  overflow: hidden;
  background: linear-gradient(160deg, #F5F7F9 0%, #EBF1FF 50%, #E0FAF7 100%);
}

/* 斜向构图装饰线 */
.hero::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 60%;
  height: 100%;
  background: linear-gradient(135deg, transparent 0%, rgba(57, 123, 255, 0.04) 50%, rgba(54, 226, 208, 0.06) 100%);
  clip-path: polygon(15% 0, 100% 0, 100% 100%, 0% 100%);
  pointer-events: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content { position: relative; z-index: 2; }

.hero-title {
  font-family: var(--font-heading);
  font-size: 3.4rem;
  font-weight: 900;
  line-height: 1.18;
  margin-bottom: 22px;
  color: var(--color-graphite);
  letter-spacing: -1px;
}

.gradient-text {
  background: linear-gradient(135deg, #397BFF 0%, #36E2D0 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.12rem;
  color: var(--text-muted);
  margin-bottom: 36px;
  line-height: 1.85;
  max-width: 520px;
}

.hero-btns {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  padding-top: 28px;
  border-top: 1px solid var(--border-light);
}

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

.stat-val {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 900;
  background: linear-gradient(135deg, #397BFF, #36E2D0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.stat-lbl {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* ===== HERO VISUAL / CANVAS ===== */
.hero-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-visual-wrapper {
  position: relative;
  width: 100%;
  max-width: 520px;
  aspect-ratio: 1;
}

#orbitCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero-core {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 3;
  text-align: center;
}

.core-sphere {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #5A9BFF, #397BFF 50%, #1A3A8A);
  box-shadow:
    0 0 40px rgba(57, 123, 255, 0.7),
    0 0 80px rgba(57, 123, 255, 0.35),
    inset 0 0 30px rgba(54, 226, 208, 0.2);
  animation: sphere-pulse 3s ease-in-out infinite;
  margin: 0 auto 16px;
  position: relative;
}
.core-sphere::after {
  content: '';
  position: absolute;
  inset: -8px;
  border-radius: 50%;
  border: 2px solid rgba(54, 226, 208, 0.4);
  animation: ring-expand 3s ease-in-out infinite;
}
@keyframes sphere-pulse {
  0%, 100% { box-shadow: 0 0 40px rgba(57,123,255,0.7), 0 0 80px rgba(57,123,255,0.35); }
  50% { box-shadow: 0 0 60px rgba(57,123,255,0.9), 0 0 120px rgba(54,226,208,0.4); }
}
@keyframes ring-expand {
  0%, 100% { transform: scale(1); opacity: 0.6; }
  50% { transform: scale(1.15); opacity: 0.2; }
}

.core-status {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(54, 226, 208, 0.4);
  border-radius: 20px;
  padding: 8px 18px;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--color-cyan-dark);
  white-space: nowrap;
  box-shadow: 0 4px 16px rgba(54, 226, 208, 0.2);
}

/* 浮动节点标签 */
.floating-node-tag {
  position: absolute;
  z-index: 5;
  padding: 8px 14px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-main);
  box-shadow: 0 6px 20px rgba(57, 123, 255, 0.15);
  display: flex;
  align-items: center;
  gap: 6px;
  border: 1px solid rgba(57, 123, 255, 0.15);
  animation: float-tag 4s ease-in-out infinite alternate;
}
.floating-node-tag.tag-hk { top: 8%; left: 2%; animation-delay: 0s; }
.floating-node-tag.tag-jp { top: 12%; right: 0%; animation-delay: 0.8s; }
.floating-node-tag.tag-sg { bottom: 18%; left: 0%; animation-delay: 1.6s; }
.floating-node-tag.tag-us { bottom: 10%; right: 2%; animation-delay: 0.4s; }

@keyframes float-tag {
  0% { transform: translateY(0); }
  100% { transform: translateY(-10px); }
}

.node-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-cyan);
  box-shadow: 0 0 8px var(--color-cyan);
  flex-shrink: 0;
}

/* ===== SECTION BASE ===== */
.section {
  padding: 90px 0;
  position: relative;
}

.section-bg-alt {
  background: rgba(245, 247, 249, 0.7);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.section-header {
  text-align: center;
  max-width: 740px;
  margin: 0 auto 64px;
}

.section-subtitle {
  display: inline-block;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 16px;
  line-height: 1.25;
  letter-spacing: -0.5px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.8;
}

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

/* ===== PING SIMULATOR ===== */
.ping-simulator-box {
  background: #FFFFFF;
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-light);
  margin-top: 0;
}

.ping-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 32px;
  flex-wrap: wrap;
  gap: 16px;
}

.ping-title-area h3 {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
}

.ping-status-dot {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--color-cyan-dark);
  font-weight: 600;
  margin-top: 4px;
}
.ping-status-dot::before {
  content: '';
  display: block;
  width: 8px;
  height: 8px;
  background: var(--color-cyan);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--color-cyan);
  animation: pulse-dot 2s infinite;
}

.node-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.node-card {
  background: var(--bg-main);
  border-radius: var(--radius-lg);
  padding: 22px 20px;
  border: 1px solid var(--border-light);
  transition: var(--transition-smooth);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.node-card::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-cyan));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.node-card:hover {
  border-color: rgba(57, 123, 255, 0.3);
  box-shadow: 0 8px 24px rgba(57, 123, 255, 0.12);
  transform: translateY(-2px);
}
.node-card:hover::before { transform: scaleX(1); }

.node-card.pinging {
  border-color: rgba(54, 226, 208, 0.4);
}

.node-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.node-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-main);
}

.node-tag {
  font-size: 0.72rem;
  padding: 3px 9px;
  border-radius: 10px;
  font-weight: 700;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
}

.node-latency {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--color-cyan-dark);
  margin-bottom: 10px;
}

.node-latency.high { color: #F59E0B; }
.node-latency.very-high { color: #EF4444; }

.node-status-bar {
  height: 4px;
  background: #E5EAF0;
  border-radius: 2px;
  overflow: hidden;
}

.node-status-progress {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-cyan));
  border-radius: 2px;
  transition: width 0.6s ease;
}

/* ===== FEATURES GRID ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: #FFFFFF;
  border-radius: var(--radius-xl);
  padding: 40px 32px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  transition: var(--transition-smooth);
  position: relative;
  overflow: hidden;
}

.feature-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-cyan));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(57, 123, 255, 0.2);
}
.feature-card:hover::after { transform: scaleX(1); }

.card-icon-wrap {
  width: 60px;
  height: 60px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 900;
  margin-bottom: 24px;
  font-family: var(--font-heading);
}

.icon-blue { background: rgba(57, 123, 255, 0.10); color: var(--color-primary); }
.icon-cyan { background: rgba(54, 226, 208, 0.10); color: var(--color-cyan-dark); }
.icon-purple { background: rgba(139, 92, 246, 0.10); color: #7C3AED; }
.icon-orange { background: rgba(245, 158, 11, 0.10); color: #D97706; }
.icon-green { background: rgba(16, 185, 129, 0.10); color: #059669; }
.icon-pink { background: rgba(236, 72, 153, 0.10); color: #BE185D; }

.card-title {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}

.card-desc {
  color: var(--text-muted);
  font-size: 0.97rem;
  line-height: 1.75;
}

/* ===== AUDIENCE GRID ===== */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.audience-card {
  background: #FFFFFF;
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  transition: var(--transition-smooth);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.audience-card::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-cyan));
  transform: scaleX(0);
  transition: transform 0.35s ease;
}

.audience-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--border-hover);
}
.audience-card:hover::before { transform: scaleX(1); }

.audience-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: rgba(57, 123, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--color-primary);
  transition: all 0.3s ease;
}
.audience-card:hover .audience-icon {
  background: var(--color-primary);
  color: #FFFFFF;
  transform: translateY(-2px);
}
.audience-icon svg {
  width: 26px;
  height: 26px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.audience-title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-main);
}

.audience-desc {
  font-size: 0.93rem;
  color: var(--text-muted);
  line-height: 1.7;
}

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

.pricing-card {
  background: #FFFFFF;
  border-radius: var(--radius-xl);
  padding: 44px 36px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.35s ease;
}

.pricing-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
}

.pricing-card.popular {
  border: 2px solid var(--color-primary);
  background: linear-gradient(160deg, #FFFFFF 0%, rgba(235, 241, 255, 0.5) 100%);
  box-shadow: 0 16px 48px rgba(57, 123, 255, 0.22);
  transform: scale(1.03);
}
.pricing-card.popular:hover {
  transform: scale(1.03) translateY(-8px);
}

.popular-badge {
  position: absolute;
  top: -16px;
  right: 28px;
  background: linear-gradient(135deg, #397BFF 0%, #36E2D0 100%);
  color: #FFFFFF;
  font-size: 0.82rem;
  font-weight: 800;
  padding: 6px 18px;
  border-radius: 20px;
  box-shadow: 0 4px 14px rgba(57, 123, 255, 0.4);
  letter-spacing: 0.5px;
}

.plan-name {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--text-main);
}

.plan-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  line-height: 1.6;
}

.plan-price-box {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 28px;
}

.price-currency {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-primary);
}

.price-amount {
  font-family: var(--font-heading);
  font-size: 3.2rem;
  font-weight: 900;
  color: var(--color-primary);
  line-height: 1;
}

.price-period {
  font-size: 0.95rem;
  color: var(--text-muted);
  font-weight: 500;
}

.plan-features {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
}

.plan-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.check-icon {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-cyan));
  color: #FFFFFF;
  font-size: 0.75rem;
  font-weight: 900;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 1px;
}

/* ===== TUTORIAL STEPS ===== */
.tutorial-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  counter-reset: step-counter;
}

.step-card {
  background: #FFFFFF;
  border-radius: var(--radius-xl);
  padding: 40px 32px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  transition: var(--transition-smooth);
  position: relative;
}

.step-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(57, 123, 255, 0.2);
}

.step-num {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 900;
  background: linear-gradient(135deg, rgba(57, 123, 255, 0.15), rgba(54, 226, 208, 0.15));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 20px;
  position: relative;
}
.step-num::after {
  content: '';
  display: block;
  width: 40px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-cyan));
  border-radius: 2px;
  margin-top: 8px;
}

.step-title {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}

.step-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.75;
}

.step-desc a {
  color: var(--color-primary);
  font-weight: 600;
}

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

.review-card {
  background: #FFFFFF;
  border-radius: var(--radius-xl);
  padding: 36px 30px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  transition: var(--transition-smooth);
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.review-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
}

.review-stars {
  font-size: 1.1rem;
  color: #F59E0B;
  letter-spacing: 2px;
}

.review-text {
  font-size: 0.97rem;
  color: var(--text-muted);
  line-height: 1.8;
  flex: 1;
  font-style: italic;
}

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

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #397BFF, #36E2D0);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 800;
  color: #FFFFFF;
  flex-shrink: 0;
}

.author-info h5 {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-main);
}
.author-info p {
  font-size: 0.82rem;
  color: var(--text-light);
}

/* ===== FAQ ACCORDION ===== */
.faq-accordion {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  background: #FFFFFF;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  overflow: hidden;
  transition: var(--transition-smooth);
  box-shadow: 0 2px 12px rgba(57, 123, 255, 0.06);
}

.faq-item.active {
  border-color: rgba(57, 123, 255, 0.3);
  box-shadow: 0 4px 20px rgba(57, 123, 255, 0.10);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 28px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-main);
  gap: 16px;
  transition: var(--transition-smooth);
  user-select: none;
}
.faq-question:hover { color: var(--color-primary); }

.faq-icon {
  font-size: 0.9rem;
  color: var(--color-primary);
  transition: transform 0.3s ease;
  flex-shrink: 0;
  line-height: 1;
}
.faq-item.active .faq-icon { transform: rotate(180deg); }

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
  max-height: 300px;
}

.faq-answer p {
  padding: 0 28px 24px;
  font-size: 0.97rem;
  color: var(--text-muted);
  line-height: 1.8;
}

.read-more-link {
  color: var(--color-primary);
  font-weight: 600;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition-smooth);
}
.read-more-link:hover {
  color: var(--color-primary-dark);
  gap: 10px;
}

/* ===== ARTICLES GRID ===== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-card {
  background: #FFFFFF;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: var(--transition-smooth);
  display: flex;
  flex-direction: column;
}
.article-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(57, 123, 255, 0.2);
}

.article-body {
  padding: 28px 28px 24px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.article-tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 20px;
  background: rgba(57, 123, 255, 0.08);
  color: var(--color-primary);
  margin-bottom: 14px;
  align-self: flex-start;
  letter-spacing: 0.5px;
}

.article-title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.5;
  flex: 1;
}
.article-title a {
  color: var(--text-main);
}
.article-title a:hover { color: var(--color-primary); }

.article-excerpt {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.7;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-light);
  padding-top: 16px;
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ===== CTA BANNER ===== */
.cta-banner {
  background: linear-gradient(135deg, #397BFF 0%, #1A3A8A 50%, #0A1A40 100%);
  border-radius: var(--radius-xl);
  padding: 72px 60px;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(57, 123, 255, 0.4);
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(54, 226, 208, 0.15) 0%, transparent 65%);
  pointer-events: none;
}

.cta-banner::after {
  content: '';
  position: absolute;
  bottom: -40%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(54, 226, 208, 0.10) 0%, transparent 65%);
  pointer-events: none;
}

.cta-title {
  font-family: var(--font-heading);
  font-size: 2.4rem;
  font-weight: 900;
  color: #FFFFFF;
  margin-bottom: 16px;
  position: relative;
  z-index: 2;
}

.cta-desc {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.78);
  margin-bottom: 36px;
  line-height: 1.8;
  position: relative;
  z-index: 2;
}

/* ===== FOOTER ===== */
.footer {
  background: var(--color-graphite);
  color: rgba(255,255,255,0.7);
  padding-top: 64px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer-brand p {
  font-size: 0.93rem;
  line-height: 1.8;
  margin-top: 16px;
  color: rgba(255,255,255,0.55);
}

.footer-brand .logo {
  color: #FFFFFF;
}
.footer-brand .logo-text span {
  background: linear-gradient(135deg, #397BFF, #36E2D0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.footer-title {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 700;
  color: #FFFFFF;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.55);
  transition: var(--transition-smooth);
}
.footer-links a:hover {
  color: var(--color-cyan);
  padding-left: 4px;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 0;
  font-size: 0.88rem;
  color: rgba(255,255,255,0.35);
  flex-wrap: wrap;
  gap: 12px;
}

.legal-links {
  display: flex;
  gap: 20px;
}
.legal-links a {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.35);
}
.legal-links a:hover { color: var(--color-cyan); }

/* ===== ARTICLE PAGE STYLES ===== */
main.container {
  padding-top: 48px;
  padding-bottom: 80px;
}

.article-header {
  max-width: 860px;
  margin: 0 auto 40px;
}

.breadcrumb {
  font-size: 0.88rem;
  color: var(--text-light);
  margin-bottom: 20px;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb span { color: var(--text-main); }

.article-main-title {
  font-family: var(--font-heading);
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--text-main);
  line-height: 1.3;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.88rem;
  color: var(--text-light);
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 24px;
}

.article-content-wrapper {
  max-width: 860px;
  margin: 0 auto;
}

.article-body-text h2 {
  font-family: var(--font-heading);
  font-size: 1.55rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 40px 0 16px;
  padding-left: 16px;
  border-left: 4px solid var(--color-primary);
}

.article-body-text h3 {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 28px 0 12px;
}

.article-body-text p {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.9;
  margin-bottom: 18px;
}

.article-body-text ul, .article-body-text ol {
  padding-left: 24px;
  margin-bottom: 18px;
  list-style: disc;
}

.article-body-text ol { list-style: decimal; }

.article-body-text li {
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.85;
  margin-bottom: 8px;
}

.article-body-text strong { color: var(--text-main); }

.in-article-cta {
  background: linear-gradient(135deg, rgba(57, 123, 255, 0.07) 0%, rgba(54, 226, 208, 0.07) 100%);
  border: 1px solid rgba(57, 123, 255, 0.18);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin: 32px 0;
}

.in-article-cta h4 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
}

.in-article-cta p {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 16px !important;
}

/* Related Articles */
.related-articles {
  margin-top: 60px;
  padding-top: 40px;
  border-top: 1px solid var(--border-light);
}

.related-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 24px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.related-item {
  background: #FFFFFF;
  border-radius: var(--radius-md);
  padding: 20px;
  border: 1px solid var(--border-light);
  box-shadow: 0 2px 10px rgba(57, 123, 255, 0.06);
  transition: var(--transition-smooth);
}
.related-item:hover {
  border-color: rgba(57, 123, 255, 0.25);
  box-shadow: var(--shadow-card);
  transform: translateY(-3px);
}
.related-item-tag {
  font-size: 0.75rem;
  color: var(--color-primary);
  font-weight: 700;
  margin-bottom: 8px;
}
.related-item-title {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.5;
}
.related-item-title a { color: var(--text-main); }
.related-item-title a:hover { color: var(--color-primary); }

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

.articles-page-hero {
  background: linear-gradient(135deg, #F5F7F9 0%, #EBF1FF 100%);
  padding: 60px 0 48px;
  border-bottom: 1px solid var(--border-light);
}
.articles-page-hero h1 {
  font-family: var(--font-heading);
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 12px;
}
.articles-page-hero p {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Tutorials page */
.tutorial-platform-tabs {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}
.platform-tab {
  padding: 10px 22px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.93rem;
  cursor: pointer;
  border: 1.5px solid var(--border-light);
  background: #FFFFFF;
  color: var(--text-muted);
  transition: var(--transition-smooth);
}
.platform-tab.active, .platform-tab:hover {
  background: linear-gradient(135deg, #397BFF, #36E2D0);
  color: #FFFFFF;
  border-color: transparent;
  box-shadow: 0 4px 14px rgba(57, 123, 255, 0.35);
}

.tutorial-section {
  background: #FFFFFF;
  border-radius: var(--radius-xl);
  padding: 40px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  margin-bottom: 32px;
}
.tutorial-section h2 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.tutorial-section h2 .step-badge {
  background: linear-gradient(135deg, #397BFF, #36E2D0);
  color: #FFF;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  font-weight: 900;
  flex-shrink: 0;
}
.tutorial-section ol, .tutorial-section ul {
  padding-left: 24px;
}
.tutorial-section ol { list-style: decimal; }
.tutorial-section ul { list-style: disc; }
.tutorial-section li {
  color: var(--text-muted);
  font-size: 0.97rem;
  line-height: 1.85;
  margin-bottom: 10px;
}

/* Legal pages */
.legal-page-content {
  max-width: 860px;
  margin: 0 auto;
  padding: 60px 0 80px;
}
.legal-page-content h1 {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 8px;
}
.legal-page-content .legal-date {
  font-size: 0.88rem;
  color: var(--text-light);
  margin-bottom: 36px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-light);
}
.legal-page-content h2 {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 32px 0 12px;
}
.legal-page-content p, .legal-page-content li {
  font-size: 0.97rem;
  color: var(--text-muted);
  line-height: 1.85;
  margin-bottom: 12px;
}
.legal-page-content ul {
  list-style: disc;
  padding-left: 24px;
  margin-bottom: 16px;
}

/* FAQ page */
.faq-page-hero {
  background: linear-gradient(135deg, #F5F7F9 0%, #EBF1FF 100%);
  padding: 60px 0 48px;
  border-bottom: 1px solid var(--border-light);
  text-align: center;
}
.faq-category {
  margin-bottom: 48px;
}
.faq-category-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.faq-category-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-light);
}

/* ===== SCROLL ANIMATIONS ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== MOBILE MENU ===== */
.mobile-nav {
  display: none;
  position: fixed;
  top: 76px;
  left: 0;
  right: 0;
  background: rgba(245, 247, 249, 0.98);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-light);
  padding: 20px 24px;
  z-index: 999;
  flex-direction: column;
  gap: 4px;
  box-shadow: 0 10px 30px rgba(57, 123, 255, 0.12);
}
.mobile-nav.open { display: flex; }
.mobile-nav .nav-link {
  padding: 12px 0;
  border-bottom: 1px solid var(--border-light);
  font-size: 1.05rem;
}
.mobile-nav .btn {
  margin-top: 16px;
  width: 100%;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .hero-title { font-size: 2.8rem; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .audience-grid { grid-template-columns: repeat(2, 1fr); }
  .node-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}

@media (max-width: 768px) {
  .nav-links, .nav-actions { display: none; }
  .mobile-menu-btn { display: block; }

  .hero { padding: 60px 0 72px; }
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .hero-visual { order: -1; }
  .hero-visual-wrapper { max-width: 340px; margin: 0 auto; }
  .hero-title { font-size: 2.2rem; }
  .hero-stats { grid-template-columns: repeat(3, 1fr); gap: 12px; }

  .section { padding: 60px 0; }
  .section-title { font-size: 1.85rem; }

  .features-grid, .pricing-grid, .tutorial-steps, .reviews-grid,
  .articles-grid, .articles-page-grid { grid-template-columns: 1fr; }

  .audience-grid { grid-template-columns: repeat(2, 1fr); }
  .node-grid { grid-template-columns: repeat(2, 1fr); }

  .pricing-card.popular { transform: scale(1); }

  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }

  .cta-banner { padding: 48px 28px; }
  .cta-title { font-size: 1.8rem; }

  .article-main-title { font-size: 1.7rem; }
  .related-grid { grid-template-columns: 1fr; }
  .ping-simulator-box { padding: 24px 20px; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 1.8rem; }
  .stat-val { font-size: 1.5rem; }
  .audience-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; }
  .hero-btns .btn { width: 100%; }
}