* {
  box-sizing: border-box;
}

:root {
  --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
  --blue: #2980FE;
  --blue-dark: #1768E8;
  --text: #202737;
  --muted: #657085;
  --light: #F6F8FC;
  --line: #E6EAF2;
  --panel: #FFFFFF;
  --soft-blue: #EEF5FF;
  --shadow: 0 18px 45px rgba(28, 45, 84, 0.10);
  --radius-lg: 30px;
  --radius-md: 22px;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.72;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

p {
  margin: 0 0 16px;
  color: var(--muted);
}

h1, h2, h3 {
  margin: 0;
  line-height: 1.22;
  color: var(--text);
}

ul, ol {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(230, 234, 242, 0.86);
}

.header-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.logo-img {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  object-fit: cover;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
  letter-spacing: 0.02em;
}

.site-nav {
  display: none;
  position: absolute;
  left: 16px;
  right: 16px;
  top: 70px;
  padding: 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
}

.site-nav a {
  display: block;
  padding: 10px 12px;
  border-radius: 12px;
  color: #364154;
  font-size: 15px;
}

.site-nav a.active,
.site-nav a:hover {
  background: var(--soft-blue);
  color: var(--blue);
}

.nav-check {
  display: none;
}

.nav-toggle {
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 14px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  padding: 0 12px;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: #263248;
  border-radius: 999px;
}

.nav-check:checked ~ .site-nav {
  display: block;
}

.content-container,
.page-container,
.footer-inner,
.footer-bottom {
  width: min(100% - 32px, 1180px);
  margin: 0 auto;
}

.section {
  padding: 64px 0;
}

.section-soft {
  background: var(--light);
}

.section-title {
  font-size: clamp(28px, 4vw, 44px);
  margin-bottom: 18px;
  letter-spacing: -0.03em;
}

.section-kicker,
.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border-radius: 999px;
  background: var(--soft-blue);
  color: var(--blue);
  font-weight: 700;
  font-size: 13px;
  margin-bottom: 16px;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 13px 26px;
  background: var(--blue);
  color: #fff;
  border-radius: 999px;
  font-weight: 800;
  box-shadow: 0 12px 28px rgba(41, 128, 254, 0.28);
  transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
  background: var(--blue-dark);
  transform: translateY(-2px);
  box-shadow: 0 16px 32px rgba(23, 104, 232, 0.28);
}

.link-more {
  color: var(--blue);
  font-weight: 700;
}

.vpn-lab-hero {
  background: var(--gradient);
  color: #fff;
  position: relative;
  overflow: hidden;
}

.vpn-lab-hero::after {
  content: "";
  position: absolute;
  inset: auto -120px -160px auto;
  width: 360px;
  height: 360px;
  background: rgba(255, 255, 255, 0.18);
  border-radius: 50%;
  filter: blur(12px);
}

.hero-grid {
  width: min(100% - 32px, 1180px);
  margin: 0 auto;
  padding: 72px 0;
  display: grid;
  gap: 40px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-copy h1 {
  color: #fff;
  font-size: clamp(36px, 7vw, 68px);
  letter-spacing: -0.05em;
  margin-bottom: 18px;
}

.hero-copy p {
  color: rgba(255, 255, 255, 0.88);
  font-size: 17px;
  max-width: 660px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 24px 0 28px;
}

.hero-tags span,
.status-chip {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.16);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.22);
  font-size: 13px;
}

.hero-visual {
  position: relative;
  min-height: 350px;
  display: grid;
  place-items: center;
}

.hero-device-card {
  width: min(390px, 92%);
  padding: 24px;
  border-radius: 34px;
  background: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.26);
  box-shadow: 0 30px 70px rgba(20, 28, 64, 0.22);
}

.hero-device-card img {
  width: 100%;
  border-radius: 28px;
}

.float-chip {
  position: absolute;
  background: rgba(255, 255, 255, 0.94);
  color: #263248;
  border-radius: 18px;
  padding: 11px 14px;
  box-shadow: var(--shadow);
  font-weight: 800;
  font-size: 13px;
}

.float-chip.one { left: 0; top: 28px; }
.float-chip.two { right: 0; top: 92px; }
.float-chip.three { left: 18px; bottom: 70px; }
.float-chip.four { right: 18px; bottom: 24px; }

.privacy-summary {
  margin-top: -34px;
  position: relative;
  z-index: 3;
}

.summary-grid {
  display: grid;
  gap: 16px;
}

.summary-card,
.security-card,
.info-card,
.risk-card,
.faq-item,
.step-card,
.tip-box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 12px 35px rgba(28, 45, 84, 0.06);
}

.summary-card {
  padding: 24px;
}

.summary-card .label {
  display: inline-block;
  margin-bottom: 12px;
  color: #fff;
  background: var(--blue);
  border-radius: 999px;
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 800;
}

.summary-card h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.feature-grid,
.split-section,
.reverse-split {
  display: grid;
  gap: 30px;
  align-items: center;
}

.text-panel {
  padding: 0;
}

.visual-panel {
  border-radius: var(--radius-lg);
  padding: 22px;
  background: var(--light);
  border: 1px solid var(--line);
}

.visual-panel img {
  border-radius: 24px;
  margin: 0 auto;
}

.points-list {
  display: grid;
  gap: 12px;
  margin: 22px 0;
}

.points-list span,
.check-item {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  color: #465267;
}

.points-list span::before,
.check-item::before {
  content: "";
  width: 8px;
  height: 8px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--blue);
  margin-top: 10px;
}

.privacy-protection-section .privacy-panel,
.encryption-protocol-section .tech-panel {
  display: grid;
  gap: 16px;
}

.boundary-card,
.protocol-card {
  padding: 22px;
  border-radius: 24px;
  background: #fff;
  border: 1px solid var(--line);
}

.boundary-card strong,
.protocol-card strong {
  display: block;
  color: var(--text);
  margin-bottom: 8px;
}

.no-log-policy-section .policy-grid,
.device-grid,
.help-grid,
.related-grid {
  display: grid;
  gap: 16px;
}

.info-card {
  padding: 24px;
}

.info-card h3 {
  margin-bottom: 10px;
  font-size: 20px;
}

.high-speed-section {
  background: #F3F7FF;
}

.process-steps {
  display: grid;
  gap: 16px;
}

.step-card {
  padding: 22px;
  position: relative;
}

.step-no {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: var(--soft-blue);
  color: var(--blue);
  font-weight: 900;
  margin-bottom: 14px;
}

.risk-grid {
  display: grid;
  gap: 16px;
}

.risk-card {
  padding: 22px;
  border-left: 4px solid var(--blue);
}

.risk-card h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.faq-list {
  display: grid;
  gap: 14px;
}

.faq-item {
  padding: 22px;
}

.faq-item h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.cta-section {
  padding: 64px 0;
  background: var(--gradient);
  color: #fff;
  text-align: center;
}

.cta-box {
  width: min(100% - 32px, 900px);
  margin: 0 auto;
}

.cta-box h2,
.cta-box p {
  color: #fff;
}

.cta-box p {
  opacity: 0.88;
  margin: 16px auto 26px;
  max-width: 650px;
}

.page-hero {
  background: linear-gradient(180deg, #F5F8FF 0%, #FFFFFF 100%);
  padding: 58px 0 28px;
}

.page-hero h1 {
  font-size: clamp(34px, 5vw, 54px);
  letter-spacing: -0.04em;
  max-width: 850px;
  margin-bottom: 18px;
}

.page-hero p {
  max-width: 760px;
  font-size: 17px;
}

.page-layout {
  width: min(100% - 32px, 1080px);
  margin: 0 auto;
  padding: 42px 0 70px;
  display: grid;
  gap: 26px;
}

.article-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(24px, 5vw, 44px);
  box-shadow: 0 16px 40px rgba(28, 45, 84, 0.06);
}

.article-card h2 {
  font-size: 26px;
  margin: 26px 0 12px;
}

.article-card h2:first-child {
  margin-top: 0;
}

.side-panel {
  background: var(--light);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 24px;
  align-self: start;
}

.side-panel h2,
.side-panel h3 {
  margin-bottom: 12px;
  font-size: 22px;
}

.checklist {
  display: grid;
  gap: 12px;
  margin: 18px 0 24px;
}

.download-zone {
  margin-top: 26px;
  padding: 24px;
  border-radius: 24px;
  background: var(--soft-blue);
  border: 1px solid #D8E7FF;
}

.download-zone p {
  margin-bottom: 18px;
}

.download-page-steps {
  counter-reset: step;
  display: grid;
  gap: 14px;
  padding-left: 0;
  list-style: none;
}

.download-page-steps li {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 18px;
  color: #465267;
}

.download-page-steps li::before {
  counter-increment: step;
  content: counter(step);
  display: inline-grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 10px;
  background: var(--blue);
  color: #fff;
  margin-right: 10px;
  font-weight: 800;
}

.site-footer {
  background: #101827;
  color: #fff;
  padding-top: 48px;
}

.site-footer p,
.site-footer a {
  color: rgba(255, 255, 255, 0.70);
}

.footer-inner {
  display: grid;
  gap: 32px;
}

.footer-brand p {
  max-width: 420px;
}

.footer-logo span,
.footer-links h3 {
  color: #fff;
}

.footer-links {
  display: grid;
  gap: 22px;
}

.footer-links a {
  display: block;
  margin: 8px 0;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.10);
  margin-top: 32px;
  padding: 18px 0;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 14px;
  color: rgba(255,255,255,0.58);
}

@media (min-width: 720px) {
  .summary-grid,
  .no-log-policy-section .policy-grid,
  .device-grid,
  .related-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .process-steps,
  .risk-grid,
  .help-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 980px) {
  .nav-toggle {
    display: none;
  }

  .site-nav {
    position: static;
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 0;
    border: 0;
    box-shadow: none;
    background: transparent;
  }

  .site-nav a {
    padding: 8px 10px;
    font-size: 14px;
  }

  .hero-grid {
    grid-template-columns: 1.04fr 0.96fr;
    min-height: 620px;
    padding: 86px 0;
  }

  .feature-grid,
  .split-section {
    grid-template-columns: 1fr 1fr;
  }

  .reverse-split {
    grid-template-columns: 1fr 1fr;
  }

  .reverse-split .visual-panel {
    order: -1;
  }

  .privacy-protection-section .split-section {
    grid-template-columns: 0.82fr 1.18fr;
  }

  .process-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .risk-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-layout {
    grid-template-columns: minmax(0, 1fr) 310px;
  }

  .footer-inner {
    grid-template-columns: 1fr 1.4fr;
  }
}

@media (max-width: 520px) {
  .header-inner {
    padding: 12px 16px;
  }

  .section {
    padding: 48px 0;
  }

  .hero-grid {
    padding: 54px 0 70px;
  }

  .float-chip {
    position: static;
    display: inline-flex;
    margin: 8px 6px 0 0;
  }

  .hero-visual {
    min-height: auto;
    display: block;
  }

  .download-btn {
    width: 100%;
  }

  .download-zone .download-btn,
  .hero-copy .download-btn,
  .cta-box .download-btn {
    width: auto;
    min-width: 180px;
  }

  .article-card,
  .side-panel {
    border-radius: 24px;
  }
}