/* 基础排版 */
:root {
  --brand-gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
  --blue: #2980FE;
  --blue-dark: #1768E8;
  --text: #1f2937;
  --muted: #667085;
  --light: #f5f7fb;
  --line: #e5eaf3;
  --white: #ffffff;
  --shadow: 0 18px 45px rgba(31, 41, 55, 0.08);
  --radius: 28px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: #ffffff;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.75;
  overflow-x: hidden;
}

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

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

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

h1, h2, h3 {
  margin: 0 0 16px;
  line-height: 1.25;
  color: #111827;
}

h1 {
  font-size: clamp(34px, 9vw, 68px);
  letter-spacing: -0.06em;
}

h2 {
  font-size: clamp(28px, 6vw, 46px);
  letter-spacing: -0.04em;
}

h3 {
  font-size: 20px;
}

.container {
  width: min(1120px, calc(100% - 36px));
  margin: 0 auto;
}

.container.narrow {
  width: min(860px, calc(100% - 36px));
}

.gradient-bg {
  background: var(--brand-gradient);
}

.soft-bg {
  background: #f6f8fd;
}

.section-heading {
  margin-bottom: 28px;
}

.section-heading p {
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}

.section-kicker,
.eyebrow,
.page-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--blue);
  background: rgba(41, 128, 254, 0.09);
  border: 1px solid rgba(41, 128, 254, 0.16);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 14px;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 13px 24px;
  color: #ffffff;
  background: #2980FE;
  border-radius: 999px;
  font-weight: 800;
  letter-spacing: 0.02em;
  box-shadow: 0 14px 28px rgba(41, 128, 254, 0.24);
  transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
  background: #1768E8;
  transform: translateY(-2px);
  box-shadow: 0 18px 36px rgba(23, 104, 232, 0.25);
}

.text-link {
  display: inline-flex;
  color: var(--blue);
  font-weight: 800;
  margin-top: 8px;
}

/* header / logo / responsive nav / mobile nav / desktop nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(229, 234, 243, 0.9);
}

.header-inner {
  width: min(1180px, calc(100% - 28px));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  color: #111827;
  font-size: 20px;
  flex: 0 0 auto;
}

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

.nav-toggle {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

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

.nav-toggle-label span {
  width: 19px;
  height: 2px;
  border-radius: 999px;
  background: #111827;
}

.site-nav {
  position: absolute;
  left: 14px;
  right: 14px;
  top: 72px;
  display: none;
  padding: 14px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
}

.nav-toggle:checked ~ .site-nav {
  display: grid;
}

.site-nav a {
  padding: 11px 12px;
  border-radius: 14px;
  color: #344054;
  font-size: 15px;
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--blue);
  background: rgba(41, 128, 254, 0.08);
}

/* vpn saas hero */
.vpn-saas-hero {
  position: relative;
  overflow: hidden;
  color: #ffffff;
  padding: 64px 0 88px;
  border-bottom-left-radius: 34px;
  border-bottom-right-radius: 34px;
}

.vpn-saas-hero::after {
  content: "";
  position: absolute;
  right: -10%;
  bottom: -32%;
  width: 70%;
  height: 70%;
  background: rgba(255, 255, 255, 0.16);
  transform: rotate(-12deg);
  border-radius: 42px;
}

.hero-grid {
  position: relative;
  z-index: 2;
  display: grid;
  gap: 36px;
  align-items: center;
}

.hero-copy h1,
.hero-copy p {
  color: #ffffff;
}

.hero-copy p {
  font-size: 17px;
  color: rgba(255, 255, 255, 0.86);
}

.hero-copy .eyebrow {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.16);
  border-color: rgba(255, 255, 255, 0.24);
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.hero-tags span {
  padding: 8px 12px;
  border-radius: 999px;
  color: #ffffff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.22);
  font-size: 14px;
}

.hero-visual {
  position: relative;
}

.product-shell {
  position: relative;
  padding: 18px;
  border-radius: 36px;
  background: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.24);
  box-shadow: 0 28px 70px rgba(16, 24, 40, 0.24);
}

.product-shell img {
  border-radius: 28px;
  margin: 0 auto;
}

.float-card {
  position: absolute;
  display: none;
  color: #111827;
  background: #ffffff;
  padding: 10px 14px;
  border-radius: 999px;
  font-weight: 800;
  box-shadow: var(--shadow);
  font-size: 14px;
}

.card-a { left: -8px; top: 15%; }
.card-b { right: -8px; top: 28%; }
.card-c { left: 8%; bottom: 8%; }
.card-d { right: 4%; bottom: 18%; }

/* product highlights / highlight card */
.product-highlights {
  padding: 72px 0 34px;
  background: #ffffff;
}

.highlight-grid,
.policy-grid,
.info-card-grid,
.risk-grid,
.privacy-cards,
.mini-grid {
  display: grid;
  gap: 16px;
}

.highlight-card,
.policy-grid article,
.info-card-grid article,
.risk-grid article,
.privacy-cards article {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 22px;
  box-shadow: 0 12px 30px rgba(31, 41, 55, 0.05);
}

.highlight-card {
  position: relative;
  overflow: hidden;
}

.highlight-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  background: var(--blue);
}

.highlight-card a,
.policy-grid a,
.risk-grid a,
.side-panel a {
  color: var(--blue);
  font-weight: 800;
}

.mini-label {
  display: inline-flex;
  color: var(--blue);
  font-weight: 900;
  margin-bottom: 12px;
}

/* content container / shared feature sections */
.feature-section,
.content-section,
.process-section,
.safety-panel,
.faq-summary,
.cta-section {
  padding: 72px 0;
}

.split-panel,
.speed-panel,
.protocol-panel,
.privacy-panel,
.article-layout {
  display: grid;
  gap: 26px;
  align-items: center;
}

.feature-copy,
.article-card,
.side-panel,
.privacy-panel,
.protocol-panel,
.cta-card,
.page-hero .container {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px;
  box-shadow: var(--shadow);
}

/* vpn connection section */
.vpn-connection-section {
  background: linear-gradient(180deg, #ffffff 0%, #f8faff 100%);
}

.feature-image {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 32px;
  padding: 18px;
  box-shadow: var(--shadow);
}

.glass-card {
  background: linear-gradient(180deg, #ffffff 0%, #f4f7ff 100%);
}

.check-list {
  list-style: none;
  padding: 0;
  margin: 18px 0;
  display: grid;
  gap: 10px;
}

.check-list li {
  position: relative;
  padding-left: 28px;
  color: #344054;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--blue);
  font-weight: 900;
}

.service-boundary,
.notice-box,
.soft-note {
  border-left: 4px solid var(--blue);
  background: #f4f8ff;
  color: #4b5563;
  padding: 14px 16px;
  border-radius: 16px;
}

/* high speed section */
.high-speed-section {
  position: relative;
}

.speed-panel {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 34px;
  padding: 22px;
  box-shadow: var(--shadow);
}

.speed-image {
  border-radius: 28px;
  overflow: hidden;
  background: #eef4ff;
}

.mini-grid {
  grid-template-columns: 1fr;
  margin: 20px 0;
}

.mini-grid div {
  border-radius: 20px;
  border: 1px solid var(--line);
  padding: 16px;
  background: #f9fbff;
}

.mini-grid strong,
.mini-grid span {
  display: block;
}

.mini-grid span {
  color: var(--muted);
  font-size: 14px;
}

/* global nodes section */
.node-card {
  background: radial-gradient(circle at top left, rgba(41, 128, 254, 0.10), #ffffff 52%);
}

/* privacy protection section */
.privacy-panel {
  text-align: center;
}

.privacy-layout {
  display: grid;
  gap: 22px;
  align-items: center;
  margin: 12px 0 20px;
}

.privacy-layout img {
  border-radius: 28px;
  box-shadow: var(--shadow);
}

/* no log policy section */
.no-log-policy-section {
  background: #ffffff;
}

/* multi device section */
.device-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0;
}

.device-chips span {
  padding: 8px 12px;
  border-radius: 999px;
  background: #eef5ff;
  color: var(--blue);
  font-weight: 800;
}

.device-card {
  background: linear-gradient(135deg, #ffffff, #eef4ff);
}

/* encryption protocol section */
.protocol-panel {
  background: linear-gradient(135deg, #ffffff 0%, #f4f6ff 100%);
}

.protocol-card {
  position: relative;
  border-radius: 30px;
  overflow: hidden;
  background: #ffffff;
}

.protocol-lines {
  position: absolute;
  left: 22px;
  right: 22px;
  bottom: 22px;
  display: grid;
  gap: 8px;
}

.protocol-lines span {
  display: block;
  height: 8px;
  border-radius: 999px;
  background: rgba(41, 128, 254, 0.18);
}

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

.process-steps article {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 22px;
  box-shadow: 0 10px 26px rgba(31, 41, 55, 0.05);
}

.process-steps article span {
  display: inline-flex;
  color: var(--blue);
  font-size: 24px;
  font-weight: 900;
  margin-bottom: 10px;
}

.process-steps article a {
  display: inline-flex;
  color: var(--blue);
  font-weight: 800;
  margin-top: 4px;
}

/* safety panel / risk grid */
.safety-panel {
  background: #ffffff;
}

.risk-grid article {
  border-top: 4px solid var(--blue);
}

.risk-grid strong,
.risk-grid span {
  display: block;
}

.risk-grid strong {
  color: #111827;
  margin-top: 10px;
}

.risk-grid span {
  color: var(--muted);
  margin-bottom: 10px;
}

/* FAQ item */
.faq-list {
  display: grid;
  gap: 14px;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 18px 20px;
  box-shadow: 0 10px 26px rgba(31, 41, 55, 0.04);
}

.faq-item summary {
  cursor: pointer;
  font-weight: 900;
  color: #111827;
}

.faq-item p {
  margin-top: 12px;
}

.faq-list.large {
  gap: 16px;
}

/* CTA */
.cta-section {
  color: #ffffff;
}

.cta-card {
  text-align: center;
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.20);
  box-shadow: 0 28px 70px rgba(16, 24, 40, 0.16);
}

.cta-card h2,
.cta-card p {
  color: #ffffff;
}

.cta-card p {
  color: rgba(255, 255, 255, 0.84);
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

/* pages */
.page-hero {
  padding: 58px 0 36px;
  background: linear-gradient(180deg, #f6f8ff 0%, #ffffff 100%);
}

.page-hero.simple {
  background: radial-gradient(circle at top left, rgba(41,128,254,.12), transparent 34%), linear-gradient(180deg, #f6f8ff 0%, #ffffff 100%);
}

.page-hero .container {
  text-align: center;
}

.article-card h2 {
  margin-top: 26px;
}

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

.side-panel {
  align-self: start;
  display: grid;
  gap: 10px;
}

.side-panel a {
  display: block;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 12px 14px;
  background: #f9fbff;
}

.info-card-grid {
  margin: 24px 0;
}

.center-action {
  text-align: center;
  margin-top: 28px;
}

/* footer */
.site-footer {
  background: #101828;
  color: #ffffff;
  padding: 56px 0 0;
}

.footer-grid {
  display: grid;
  gap: 26px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  font-size: 20px;
  margin-bottom: 12px;
}

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

.site-footer h3 {
  color: #ffffff;
  font-size: 16px;
}

.site-footer p,
.footer-bottom p {
  color: rgba(255, 255, 255, 0.68);
}

.site-footer a {
  display: block;
  color: rgba(255, 255, 255, 0.78);
  margin: 8px 0;
}

.site-footer a:hover {
  color: #ffffff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  text-align: center;
  margin-top: 36px;
  padding: 18px;
}

/* 平板 */
@media (min-width: 640px) {
  .highlight-grid,
  .policy-grid,
  .info-card-grid,
  .risk-grid,
  .process-steps,
  .privacy-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .mini-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .float-card {
    display: block;
  }

  .feature-copy,
  .article-card,
  .side-panel,
  .privacy-panel,
  .protocol-panel,
  .cta-card,
  .page-hero .container {
    padding: 34px;
  }
}

/* 电脑 */
@media (min-width: 960px) {
  .nav-toggle-label {
    display: none;
  }

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

  .vpn-saas-hero {
    padding: 92px 0 116px;
    border-bottom-left-radius: 70px;
    border-bottom-right-radius: 70px;
  }

  .hero-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 54px;
  }

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

  .split-panel,
  .speed-panel,
  .protocol-panel,
  .privacy-layout,
  .article-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .split-panel.reverse {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  }

  .split-panel.reverse .feature-copy {
    order: 2;
  }

  .split-panel.reverse .feature-image {
    order: 1;
  }

  .protocol-panel {
    grid-template-columns: 0.9fr 1.1fr;
  }

  .privacy-panel {
    text-align: left;
  }

  .privacy-panel .section-heading p {
    margin-left: 0;
  }

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

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

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

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

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

  .article-layout {
    align-items: start;
  }

  .article-layout.staggered {
    grid-template-columns: minmax(0, 1fr) 320px;
  }

  .article-layout.wide-aside {
    grid-template-columns: minmax(0, 0.95fr) minmax(280px, 0.45fr);
  }
}

@media (min-width: 1180px) {
  .hero-copy p {
    font-size: 18px;
  }

  .product-shell {
    transform: rotate(1.5deg);
  }
}