:root {
  --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
  --blue: #2980FE;
  --blue-dark: #1768E8;
  --text: #20263A;
  --muted: #657086;
  --light: #F6F8FC;
  --soft-blue: #F1F6FF;
  --border: #E6EAF2;
  --white: #FFFFFF;
  --shadow: 0 18px 45px rgba(32, 38, 58, 0.08);
  --radius: 28px;
}
* { box-sizing: border-box; }
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: 1.7;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.container { width: min(100% - 32px, 1180px); margin: 0 auto; }
.section-pad { padding: 58px 0; }
.gradient-bg { background: var(--gradient); }
.soft-bg { background: var(--light); }
.soft-blue { background: var(--soft-blue); }
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,0.94);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(230,234,242,0.8);
}
.nav-shell {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: #12182B; }
.logo-img { width: 42px; height: 42px; object-fit: cover; border-radius: 12px; box-shadow: 0 8px 18px rgba(41,128,254,0.18); }
.brand-text { font-size: 17px; white-space: nowrap; }
.nav-toggle { position: absolute; opacity: 0; pointer-events: none; }
.nav-toggle-label {
  width: 44px;
  height: 44px;
  border: 1px solid var(--border);
  border-radius: 14px;
  display: grid;
  place-content: center;
  gap: 5px;
  cursor: pointer;
  background: #fff;
}
.nav-toggle-label span { width: 20px; height: 2px; background: #252B3D; border-radius: 999px; display: block; }
.main-nav {
  position: absolute;
  left: 16px;
  right: 16px;
  top: 78px;
  display: none;
  flex-direction: column;
  padding: 14px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 22px;
  box-shadow: var(--shadow);
}
.main-nav a { padding: 11px 12px; color: #465066; border-radius: 12px; font-size: 15px; }
.main-nav a.active, .main-nav a:hover { color: var(--blue); background: #F2F7FF; }
.nav-toggle:checked ~ .main-nav { display: flex; }
.vpn-saas-hero {
  color: #fff;
  padding: 70px 0 60px;
  position: relative;
  overflow: hidden;
}
.vpn-saas-hero::after {
  content: "";
  position: absolute;
  inset: auto -10% -70px -10%;
  height: 140px;
  background: #fff;
  transform: skewY(-3deg);
  transform-origin: left top;
}
.hero-grid { position: relative; z-index: 1; display: grid; gap: 42px; align-items: center; }
.hero-copy h1 { font-size: clamp(36px, 9vw, 68px); line-height: 1.08; margin: 14px 0 20px; letter-spacing: -0.04em; }
.hero-copy p { max-width: 680px; color: rgba(255,255,255,0.88); font-size: 17px; margin: 0 0 28px; }
.eyebrow, .section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--blue);
  background: #ECF4FF;
  border-radius: 999px;
  padding: 7px 12px;
}
.vpn-saas-hero .eyebrow, .small-hero .eyebrow, .section-kicker.light { color: #fff; background: rgba(255,255,255,0.16); }
.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 24px;
  border-radius: 999px;
  background: #2980FE;
  color: #fff;
  font-weight: 800;
  box-shadow: 0 12px 24px rgba(41,128,254,0.28);
  transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: #1768E8; transform: translateY(-2px); box-shadow: 0 16px 30px rgba(23,104,232,0.32); }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.hero-tags span, .info-chips span, .device-stack span {
  display: inline-flex;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,0.14);
  border: 1px solid rgba(255,255,255,0.22);
  color: #fff;
  font-size: 13px;
}
.hero-visual { position: relative; min-height: 360px; display: grid; place-items: center; }
.device-card {
  width: min(86vw, 430px);
  padding: 18px;
  border-radius: 36px;
  background: rgba(255,255,255,0.20);
  border: 1px solid rgba(255,255,255,0.26);
  box-shadow: 0 26px 70px rgba(17, 25, 65, .25);
}
.device-card img { border-radius: 28px; width: 100%; object-fit: cover; }
.float-card {
  position: absolute;
  background: rgba(255,255,255,0.92);
  color: #26304A;
  padding: 10px 14px;
  border-radius: 16px;
  font-size: 13px;
  font-weight: 800;
  box-shadow: 0 18px 40px rgba(30,39,70,0.18);
}
.card-a { top: 18px; left: 6px; }
.card-b { top: 72px; right: 0; }
.card-c { bottom: 62px; left: 0; }
.card-d { bottom: 18px; right: 20px; }
.section-heading { text-align: center; max-width: 780px; margin: 0 auto 30px; }
.section-heading.left { text-align: left; margin-left: 0; }
.section-heading.compact { margin-bottom: 22px; }
.section-heading h2, .text-panel h2, .wide-card h2, .tech-panel h2 { font-size: clamp(28px, 5vw, 42px); line-height: 1.18; margin: 14px 0 12px; letter-spacing: -0.03em; }
.section-heading p, .text-panel p, .wide-card p, .tech-panel p { color: var(--muted); margin: 0; }
.highlight-grid { display: grid; gap: 16px; }
.highlight-card, .content-card, .side-note, .three-card-grid article, .risk-grid article, .steps-grid article, .privacy-cards article, .safety-note-grid article {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 24px;
  box-shadow: 0 12px 35px rgba(32,38,58,0.05);
}
.highlight-card { padding: 22px; }
.highlight-card h3 { margin: 14px 0 8px; font-size: 20px; }
.highlight-card p { color: var(--muted); margin: 0 0 14px; font-size: 15px; }
.highlight-card a, .text-link, .steps-grid a, .risk-grid a, .side-note a { color: var(--blue); font-weight: 800; }
.mini-label, .category-badge {
  display: inline-flex;
  padding: 5px 10px;
  border-radius: 999px;
  background: #ECF4FF;
  color: var(--blue);
  font-size: 12px;
  font-weight: 800;
}
.split-panel { display: grid; gap: 24px; align-items: center; }
.image-panel { background: #fff; border: 1px solid var(--border); border-radius: 32px; padding: 16px; box-shadow: var(--shadow); }
.image-panel img { width: 100%; border-radius: 24px; object-fit: cover; }
.text-panel { padding: 4px 0; }
.feature-list { padding: 0; margin: 20px 0; list-style: none; display: grid; gap: 10px; }
.feature-list li { padding-left: 26px; position: relative; color: #4D5870; }
.feature-list li::before { content: ""; position: absolute; left: 0; top: 11px; width: 10px; height: 10px; background: var(--blue); border-radius: 50%; }
.wide-card, .privacy-board, .tech-panel {
  border-radius: 34px;
  background: #fff;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  padding: 24px;
}
.speed-card { display: grid; gap: 24px; align-items: center; background: linear-gradient(135deg, #fff 0%, #F5F9FF 100%); }
.speed-card img { border-radius: 28px; width: 100%; }
.line-metrics { display: grid; grid-template-columns: 1fr; gap: 10px; margin: 22px 0; }
.line-metrics span { background: #F1F6FF; border: 1px solid #DDEBFF; color: #2C5CB8; border-radius: 16px; padding: 12px; font-weight: 700; }
.info-chips, .device-stack { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0; }
.info-chips span, .device-stack span { background: #ECF4FF; border-color: #DDEBFF; color: #286AD3; }
.privacy-layout { display: grid; gap: 20px; align-items: center; }
.privacy-layout img { border-radius: 28px; width: 100%; }
.privacy-cards { display: grid; gap: 14px; }
.privacy-cards article { padding: 18px; }
.privacy-cards h3, .three-card-grid h3, .risk-grid h3, .steps-grid h3 { margin: 0 0 8px; }
.privacy-cards p, .three-card-grid p, .risk-grid p, .steps-grid p { color: var(--muted); margin: 0; }
.three-card-grid { display: grid; gap: 16px; }
.three-card-grid article { padding: 22px; }
.center-link { display: block; text-align: center; margin-top: 22px; }
.tech-panel { display: grid; gap: 20px; align-items: center; }
.tech-panel img { border-radius: 28px; width: 100%; }
.steps-grid { display: grid; gap: 16px; }
.steps-grid article { padding: 20px; position: relative; overflow: hidden; }
.steps-grid article span { display: inline-flex; width: 42px; height: 42px; border-radius: 14px; align-items: center; justify-content: center; background: #ECF4FF; color: var(--blue); font-weight: 900; margin-bottom: 12px; }
.risk-grid { display: grid; gap: 16px; }
.risk-grid article { padding: 20px; border-left: 4px solid var(--blue); }
.risk-grid strong { display: inline-block; margin-top: 12px; color: #26304A; }
.risk-grid span { color: var(--muted); display: block; margin: 2px 0 10px; }
.faq-list { display: grid; gap: 12px; }
.faq-item { border: 1px solid var(--border); border-radius: 18px; background: #fff; padding: 16px 18px; }
.faq-item summary { cursor: pointer; font-weight: 800; color: #20263A; }
.faq-item p { color: var(--muted); margin: 10px 0 0; }
.cta-section { color: #fff; padding: 64px 0; text-align: center; }
.cta-inner { max-width: 760px; }
.cta-inner h2 { font-size: clamp(30px, 6vw, 46px); line-height: 1.18; margin: 14px 0; }
.cta-inner p { color: rgba(255,255,255,0.86); margin: 0 0 24px; }
.page-hero { color: #fff; }
.small-hero { padding: 62px 0; }
.small-hero h1 { font-size: clamp(34px, 8vw, 58px); line-height: 1.12; margin: 14px 0 14px; letter-spacing: -0.04em; max-width: 880px; }
.small-hero p { max-width: 760px; color: rgba(255,255,255,0.88); margin: 0; }
.small-hero .download-btn { margin-top: 24px; }
.page-layout { display: grid; gap: 22px; align-items: start; }
.content-card { padding: 24px; }
.article-content h2 { font-size: 24px; margin: 28px 0 10px; }
.article-content h2:first-child { margin-top: 0; }
.article-content p { color: #4E596F; margin: 0 0 14px; }
.article-content .download-btn, .detail-main .download-btn, .faq-list .download-btn { margin-top: 20px; }
.side-note { padding: 22px; display: grid; gap: 12px; }
.side-note h3 { margin: 0 0 4px; }
.side-note a { padding: 10px 0; border-bottom: 1px solid var(--border); }
.footer-grid { display: grid; gap: 28px; padding: 46px 0 26px; }
.site-footer { background: #121827; color: rgba(255,255,255,0.78); }
.footer-brand { color: #fff; font-size: 20px; font-weight: 900; margin-bottom: 12px; }
.site-footer h3 { color: #fff; margin: 0 0 12px; }
.site-footer a { display: block; padding: 5px 0; color: rgba(255,255,255,0.72); }
.site-footer a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.12); padding: 18px 0 24px; display: flex; flex-direction: column; gap: 8px; font-size: 14px; }
.download-guide .content-card { margin-bottom: 20px; }
.four-steps { margin-top: 20px; }
.safety-note-grid { display: grid; gap: 16px; }
.safety-note-grid article { padding: 20px; }
.detail-page { display: grid; gap: 22px; align-items: start; }
.detail-main { overflow: hidden; }
.detail-intro { display: grid; gap: 20px; align-items: center; }
.detail-intro h2 { margin: 12px 0 0; font-size: clamp(26px, 5vw, 38px); line-height: 1.18; }
.detail-intro img { border-radius: 28px; width: 100%; background: var(--light); }
.detail-cards { margin: 22px 0; }
.check-panel { background: #F7FAFF; border: 1px solid #DFEAFF; border-radius: 24px; padding: 20px; margin-top: 18px; }
.check-panel h2 { margin: 0 0 14px; font-size: 22px; }
.check-panel ul { margin: 0; padding-left: 20px; color: #4F5D76; }
.tip-box { background: #F7FAFF; border: 1px solid #DFEAFF; border-radius: 18px; padding: 14px; margin-top: 8px; }
.tip-box p { margin: 6px 0 0; color: var(--muted); }
@media (min-width: 640px) {
  .highlight-grid, .three-card-grid, .risk-grid, .steps-grid, .safety-note-grid { grid-template-columns: repeat(2, 1fr); }
  .line-metrics { grid-template-columns: repeat(3, 1fr); }
  .footer-bottom { flex-direction: row; justify-content: space-between; }
}
@media (min-width: 900px) {
  .nav-toggle-label { display: none; }
  .main-nav { position: static; display: flex; flex-direction: row; align-items: center; gap: 2px; padding: 0; background: transparent; border: 0; box-shadow: none; }
  .main-nav a { font-size: 14px; padding: 9px 10px; }
  .hero-grid { grid-template-columns: 1.05fr .95fr; }
  .vpn-saas-hero { padding: 94px 0 88px; }
  .highlight-grid { grid-template-columns: repeat(4, 1fr); }
  .split-panel, .speed-card, .privacy-layout, .tech-panel, .detail-intro { grid-template-columns: 1fr 1fr; }
  .reverse .text-panel { order: 2; }
  .reverse .image-panel { order: 1; }
  .three-card-grid { grid-template-columns: repeat(3, 1fr); }
  .risk-grid { grid-template-columns: repeat(3, 1fr); }
  .steps-grid { grid-template-columns: repeat(3, 1fr); }
  .page-layout, .detail-page { grid-template-columns: minmax(0, 1fr) 300px; }
  .split-detail .detail-main .detail-intro { grid-template-columns: .9fr 1.1fr; }
  .footer-grid { grid-template-columns: 1.5fr 1fr 1fr 1fr; }
  .content-card { padding: 34px; }
}
@media (min-width: 1120px) {
  .main-nav a { padding: 10px 12px; }
  .section-pad { padding: 76px 0; }
  .wide-card, .privacy-board, .tech-panel { padding: 38px; }
}
@media (max-width: 420px) {
  .container { width: min(100% - 24px, 1180px); }
  .download-btn { width: 100%; }
  .brand-text { font-size: 15px; }
  .hero-visual { min-height: 310px; }
  .float-card { font-size: 12px; padding: 8px 10px; }
  .content-card { padding: 20px; }
}