:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #253047;
    --muted: #68758D;
    --light: #F5F7FB;
    --line: #E6EAF2;
    --white: #FFFFFF;
    --shadow: 0 18px 50px rgba(43, 79, 148, 0.12);
    --radius: 24px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #ffffff;
    line-height: 1.72;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }

.site-header {
    position: sticky;
    top: 0;
    z-index: 30;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(230, 234, 242, 0.92);
}
.header-inner {
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: #17223B; }
.logo img { width: 38px; height: 38px; object-fit: contain; border-radius: 12px; }
.logo span { letter-spacing: 0.02em; }
.site-nav { display: none; width: 100%; padding: 12px 0 18px; flex-direction: column; gap: 6px; }
.site-nav.open { display: flex; }
.site-nav a {
    color: #43516B;
    font-size: 15px;
    padding: 10px 12px;
    border-radius: 14px;
}
.site-nav a:hover, .site-nav a.active { color: var(--blue); background: #F1F6FF; }
.nav-toggle { display: inline-flex; flex-direction: column; justify-content: center; gap: 5px; width: 42px; height: 42px; border: 1px solid var(--line); background: #fff; border-radius: 14px; }
.nav-toggle span { width: 18px; height: 2px; background: #2D3A55; margin: 0 auto; border-radius: 2px; }

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 700;
    box-shadow: 0 14px 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 18px 32px rgba(23, 104, 232, 0.28); }
.section { padding: 72px 0; }
.section-soft { background: var(--light); }
.section-heading { max-width: 720px; margin: 0 auto 34px; text-align: center; }
.section-heading h2 { margin: 0 0 12px; font-size: clamp(28px, 5vw, 42px); line-height: 1.2; color: #18233C; }
.section-heading p { margin: 0; color: var(--muted); }
.eyebrow, .category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--blue);
    background: #EEF5FF;
    border: 1px solid #DCEBFF;
    padding: 6px 12px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 700;
    margin-bottom: 14px;
}

.vpn-network-hero {
    position: relative;
    color: #fff;
    background: var(--gradient);
    overflow: hidden;
}
.vpn-network-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 12% 20%, rgba(255,255,255,0.22) 0 2px, transparent 3px),
        radial-gradient(circle at 78% 28%, rgba(255,255,255,0.18) 0 2px, transparent 3px),
        radial-gradient(circle at 64% 76%, rgba(255,255,255,0.16) 0 2px, transparent 3px),
        linear-gradient(135deg, transparent 20%, rgba(255,255,255,0.10) 20% 21%, transparent 21% 48%, rgba(255,255,255,0.08) 48% 49%, transparent 49%);
    opacity: 0.9;
}
.hero-inner {
    position: relative;
    padding: 70px 0 80px;
    display: grid;
    gap: 44px;
    align-items: center;
}
.hero-copy h1 { margin: 0 0 18px; font-size: clamp(36px, 9vw, 64px); line-height: 1.08; letter-spacing: -0.04em; }
.hero-copy p { margin: 0 0 24px; max-width: 650px; color: rgba(255,255,255,0.88); font-size: 17px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.hero-tags span, .floating-label {
    display: inline-flex;
    align-items: center;
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,0.14);
    border: 1px solid rgba(255,255,255,0.26);
    color: #fff;
    font-size: 13px;
    backdrop-filter: blur(8px);
}
.hero-visual { position: relative; min-height: 360px; display: grid; place-items: center; }
.hero-device {
    position: relative;
    z-index: 2;
    width: min(420px, 88%);
    padding: 18px;
    border-radius: 32px;
    background: rgba(255,255,255,0.18);
    box-shadow: 0 28px 90px rgba(12, 20, 52, 0.25);
    backdrop-filter: blur(16px);
}
.hero-device img { border-radius: 24px; background: rgba(255,255,255,0.12); }
.network-orbit {
    position: absolute;
    width: 94%;
    aspect-ratio: 1;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.26);
    box-shadow: inset 0 0 70px rgba(255,255,255,0.1);
}
.floating-label { position: absolute; z-index: 3; }
.label-secure { top: 18px; left: 6%; }
.label-node { top: 28%; right: 0; }
.label-speed { bottom: 22%; left: 0; }
.label-privacy { bottom: 28px; right: 8%; }

.node-overview { margin-top: -36px; position: relative; z-index: 5; }
.node-overview-grid { display: grid; gap: 16px; }
.node-card, .feature-card, .risk-card, .faq-item, .panel-card, .step-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.node-card { padding: 24px; }
.node-card .tag { display: inline-flex; margin-bottom: 12px; color: var(--blue); font-weight: 800; font-size: 13px; }
.node-card h3 { margin: 0 0 8px; font-size: 21px; }
.node-card p { margin: 0 0 14px; color: var(--muted); }
.text-link { color: var(--blue); font-weight: 700; }
.text-link:hover { color: var(--blue-dark); }

.split-section { display: grid; gap: 30px; align-items: center; }
.split-copy h2, .page-content h2 { margin: 0 0 14px; font-size: clamp(28px, 5vw, 42px); line-height: 1.2; color: #17223B; }
.split-copy p, .page-content p, .feature-card p, .panel-card p { color: var(--muted); margin: 0 0 14px; }
.feature-list { display: grid; gap: 12px; margin: 24px 0; padding: 0; list-style: none; }
.feature-list li { padding: 14px 16px; border-radius: 18px; background: #F7FAFF; border: 1px solid #E5EEFF; color: #3D4A63; }
.image-panel { position: relative; padding: 18px; border-radius: 30px; background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); }
.image-panel img { border-radius: 22px; margin: 0 auto; }
.global-nodes-section { position: relative; overflow: hidden; }
.global-nodes-section .map-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 24px;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}
.map-panel::before {
    content: "";
    position: absolute;
    inset: 18px;
    background:
        radial-gradient(circle at 18% 25%, #2980FE 0 4px, transparent 5px),
        radial-gradient(circle at 72% 30%, #7B4EF1 0 4px, transparent 5px),
        radial-gradient(circle at 45% 70%, #B84DDA 0 4px, transparent 5px),
        linear-gradient(120deg, transparent 22%, rgba(41,128,254,0.16) 22% 23%, transparent 23% 55%, rgba(123,78,241,0.14) 55% 56%, transparent 56%);
    border-radius: 24px;
    pointer-events: none;
}
.map-panel img { position: relative; z-index: 1; }
.speed-cards, .privacy-tags, .policy-grid, .device-grid, .protocol-grid, .risk-grid, .faq-grid, .content-grid, .page-card-grid {
    display: grid;
    gap: 16px;
}
.speed-cards { margin: 22px 0; }
.speed-card { padding: 18px; border: 1px solid #DCEBFF; background: #fff; border-radius: 20px; }
.speed-card strong { color: #17223B; display: block; margin-bottom: 4px; }
.privacy-protection-section .privacy-panel { padding: 26px; }
.privacy-tags { grid-template-columns: 1fr; margin-top: 18px; }
.privacy-tags span { padding: 12px 14px; border-radius: 16px; background: #F3F7FF; color: #39506F; font-weight: 700; }
.policy-grid, .protocol-grid { margin-top: 28px; }
.feature-card, .panel-card { padding: 24px; }
.feature-card h3, .panel-card h3, .risk-card h3, .step-card h3 { margin: 0 0 8px; color: #17223B; }
.device-card { padding: 22px; border-radius: 24px; background: #fff; border: 1px solid var(--line); box-shadow: 0 12px 30px rgba(43,79,148,0.08); }
.device-card h3 { margin: 0 0 8px; }
.device-card p { margin: 0; color: var(--muted); }
.protocol-card { border-left: 4px solid var(--blue); }

.process-steps { display: grid; gap: 16px; counter-reset: step; }
.step-card { padding: 22px; position: relative; }
.step-no { display: inline-flex; width: 34px; height: 34px; align-items: center; justify-content: center; border-radius: 50%; background: var(--blue); color: #fff; font-weight: 800; margin-bottom: 12px; }
.risk-grid { margin-top: 22px; }
.risk-card { padding: 22px; border-top: 4px solid var(--blue); }
.risk-card p { color: var(--muted); margin: 0 0 10px; }
.risk-card .suggest { color: #33415B; font-weight: 700; }
.faq-item { padding: 22px; box-shadow: none; }
.faq-item h3 { margin: 0 0 8px; color: #17223B; font-size: 18px; }
.faq-item p { margin: 0; color: var(--muted); }
.cta-section {
    background: var(--gradient);
    color: #fff;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.cta-section::before { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 25% 10%, rgba(255,255,255,0.24), transparent 32%); }
.cta-section .container { position: relative; }
.cta-section h2 { margin: 0 0 12px; font-size: clamp(28px, 5vw, 44px); }
.cta-section p { max-width: 720px; margin: 0 auto 24px; color: rgba(255,255,255,0.88); }

.page-hero {
    padding: 58px 0 44px;
    background: linear-gradient(180deg, #F4F8FF 0%, #FFFFFF 100%);
    border-bottom: 1px solid var(--line);
}
.page-hero h1 { margin: 0 0 14px; font-size: clamp(34px, 7vw, 54px); line-height: 1.12; color: #17223B; letter-spacing: -0.03em; }
.page-hero p { margin: 0; max-width: 780px; color: var(--muted); font-size: 17px; }
.page-layout { display: grid; gap: 28px; align-items: start; }
.page-content { min-width: 0; }
.page-content section { margin-bottom: 28px; }
.info-box, .checklist, .side-panel, .notice-panel {
    border: 1px solid var(--line);
    border-radius: 24px;
    background: #fff;
    padding: 24px;
    box-shadow: 0 14px 35px rgba(43,79,148,0.08);
}
.info-box h2, .checklist h2, .side-panel h2, .notice-panel h2 { margin-top: 0; font-size: 24px; }
.checklist ul, .notice-panel ul { margin: 0; padding-left: 20px; color: var(--muted); }
.checklist li, .notice-panel li { margin-bottom: 8px; }
.side-panel { position: static; }
.side-panel a { display: block; padding: 12px 0; color: var(--blue); font-weight: 700; border-bottom: 1px solid var(--line); }
.side-panel a:last-child { border-bottom: 0; }
.download-wrap { margin-top: 26px; }
.download-steps { display: grid; gap: 14px; margin-top: 26px; }
.download-step { padding: 18px; border: 1px solid var(--line); border-radius: 20px; background: #fff; }
.download-step strong { color: var(--blue); display: block; margin-bottom: 4px; }

.site-footer { background: #101B31; color: rgba(255,255,255,0.76); padding: 56px 0 22px; }
.footer-grid { display: grid; gap: 28px; }
.footer-brand { color: #fff; font-size: 22px; font-weight: 800; margin-bottom: 10px; }
.site-footer h3 { color: #fff; margin: 0 0 12px; font-size: 16px; }
.site-footer a { display: block; color: rgba(255,255,255,0.72); margin-bottom: 8px; }
.site-footer a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.12); margin-top: 34px; padding-top: 18px; font-size: 14px; }
.footer-bottom p { margin: 0; }

@media (min-width: 680px) {
    .node-overview-grid, .policy-grid, .device-grid, .protocol-grid, .risk-grid, .faq-grid, .page-card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .privacy-tags { grid-template-columns: repeat(3, 1fr); }
    .process-steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 920px) {
    .nav-toggle { display: none; }
    .site-nav { display: flex; flex-direction: row; width: auto; padding: 0; align-items: center; gap: 2px; }
    .site-nav a { padding: 9px 10px; font-size: 14px; }
    .hero-inner { grid-template-columns: 1.05fr 0.95fr; padding: 90px 0 112px; }
    .split-section { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .split-section.reverse .split-copy { order: 2; }
    .split-section.reverse .image-panel, .split-section.reverse .map-panel { order: 1; }
    .node-overview-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .risk-grid, .protocol-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .process-steps { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .page-layout { grid-template-columns: minmax(0, 1fr) 320px; }
    .side-panel { position: sticky; top: 92px; }
    .footer-grid { grid-template-columns: 1.4fr repeat(3, 1fr); }
}
@media (min-width: 1120px) {
    .site-nav a { padding: 10px 12px; }
}
@media (max-width: 420px) {
    .container { width: min(100% - 24px, 1120px); }
    .section { padding: 54px 0; }
    .hero-inner { padding: 56px 0 70px; }
    .hero-visual { min-height: 310px; }
    .floating-label { font-size: 12px; padding: 7px 10px; }
    .download-btn { width: 100%; }
}