:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #64748b;
    --light: #f6f8fc;
    --line: #e5eaf3;
    --panel: #ffffff;
    --soft-blue: #eef5ff;
    --radius-xl: 34px;
    --radius-lg: 26px;
    --shadow: 0 18px 45px rgba(39, 75, 140, 0.12);
}

* { 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: #fff;
    line-height: 1.75;
    overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
p { margin: 0 0 16px; }

.container {
    width: min(100% - 32px, 1160px);
    margin: 0 auto;
}
.narrow-container {
    width: min(100% - 32px, 920px);
    margin: 0 auto;
}
.section { padding: 58px 0; }
.section-soft { background: var(--light); }
.eyebrow, .category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 13px;
    border-radius: 999px;
    background: #edf5ff;
    color: var(--blue);
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 12px;
}
.section-title { font-size: clamp(28px, 5vw, 44px); line-height: 1.18; margin: 0 0 16px; letter-spacing: -0.03em; }
.section-lead { color: var(--muted); font-size: 17px; max-width: 760px; }
.text-link { color: var(--blue); font-weight: 700; }
.text-link:hover { color: var(--blue-dark); }

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(229, 234, 243, 0.85);
}
.header-inner {
    width: min(100% - 28px, 1180px);
    margin: 0 auto;
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.brand, .footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    letter-spacing: -0.02em;
}
.logo-img, .footer-brand img {
    width: 38px;
    height: 38px;
    border-radius: 12px;
    object-fit: cover;
    box-shadow: 0 8px 20px rgba(41, 128, 254, 0.18);
}
.brand-text { font-size: 19px; }
.nav-toggle { display: none; }
.nav-toggle-label {
    width: 44px;
    height: 44px;
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    align-items: center;
    border: 1px solid var(--line);
    border-radius: 14px;
    cursor: pointer;
}
.nav-toggle-label span { width: 19px; height: 2px; border-radius: 3px; background: var(--text); }
.site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 72px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
    box-shadow: var(--shadow);
}
.nav-toggle:checked ~ .site-nav { display: flex; }
.site-nav a {
    padding: 10px 12px;
    color: #334155;
    border-radius: 12px;
    font-weight: 650;
    font-size: 15px;
}
.site-nav a:hover, .site-nav a.active { background: #eef5ff; color: var(--blue); }

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 24px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 800;
    line-height: 1;
    box-shadow: 0 16px 28px rgba(41, 128, 254, 0.25);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: var(--blue-dark); transform: translateY(-2px); box-shadow: 0 18px 34px rgba(23, 104, 232, 0.3); }

.vpn-saas-hero {
    position: relative;
    overflow: hidden;
    color: #fff;
    background: var(--gradient);
    border-bottom-left-radius: 34px;
    border-bottom-right-radius: 34px;
}
.vpn-saas-hero::after {
    content: "";
    position: absolute;
    inset: auto -10% -95px -10%;
    height: 200px;
    background: #fff;
    transform: skewY(-4deg);
    transform-origin: left top;
}
.hero-inner {
    position: relative;
    z-index: 2;
    width: min(100% - 32px, 1180px);
    margin: 0 auto;
    padding: 72px 0 96px;
    display: grid;
    gap: 40px;
    align-items: center;
}
.hero-copy h1 {
    font-size: clamp(38px, 11vw, 66px);
    line-height: 1.04;
    letter-spacing: -0.055em;
    margin: 12px 0 20px;
}
.hero-copy p { max-width: 650px; color: rgba(255,255,255,.86); font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; margin-top: 26px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.hero-tags span, .floating-card {
    border: 1px solid rgba(255,255,255,.28);
    background: rgba(255,255,255,.14);
    color: #fff;
    backdrop-filter: blur(10px);
    border-radius: 999px;
    padding: 8px 12px;
    font-weight: 700;
    font-size: 14px;
}
.hero-visual { position: relative; min-height: 360px; display: grid; place-items: center; }
.hero-phone {
    position: relative;
    z-index: 2;
    width: min(88vw, 450px);
    border-radius: 36px;
    background: rgba(255,255,255,.16);
    padding: 16px;
    box-shadow: 0 30px 60px rgba(14, 33, 93, 0.28);
}
.hero-phone img { border-radius: 28px; }
.floating-card { position: absolute; z-index: 3; box-shadow: 0 16px 35px rgba(10, 23, 78, .16); }
.float-one { top: 18px; left: 2px; }
.float-two { top: 88px; right: 0; }
.float-three { bottom: 80px; left: 0; }
.float-four { bottom: 24px; right: 34px; }

.product-highlights { margin-top: -40px; position: relative; z-index: 4; }
.highlight-grid { display: grid; gap: 18px; }
.highlight-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow);
}
.highlight-card .tag { display: inline-block; padding: 5px 10px; border-radius: 999px; color: var(--blue); background: #edf5ff; font-size: 13px; font-weight: 800; margin-bottom: 10px; }
.highlight-card h3 { margin: 0 0 8px; font-size: 20px; }
.highlight-card p { color: var(--muted); }

.feature-panel, .vpn-connection-section, .high-speed-section, .global-nodes-section, .multi-device-section, .encryption-protocol-section {
    display: grid;
    gap: 28px;
    align-items: center;
}
.feature-card, .image-card, .privacy-card, .policy-card, .protocol-card, .step-card, .risk-card, .faq-item, .guide-card, .tip-box, .download-panel, .about-panel {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: 0 14px 36px rgba(26, 48, 94, 0.08);
}
.image-card { padding: 18px; background: linear-gradient(180deg, #fff, #f7faff); }
.image-card img { border-radius: 24px; width: 100%; object-fit: cover; }
.feature-list { display: grid; gap: 12px; margin: 22px 0; padding: 0; list-style: none; }
.feature-list li { position: relative; padding-left: 24px; color: #475569; }
.feature-list li::before { content: ""; width: 9px; height: 9px; border-radius: 50%; background: var(--blue); position: absolute; left: 0; top: .75em; }
.high-speed-section { background: #f4f8ff; border-radius: var(--radius-xl); padding: 26px; }
.speed-metrics { display: grid; gap: 14px; margin-top: 18px; }
.metric { padding: 16px; background: #fff; border: 1px solid var(--line); border-radius: 20px; }
.metric strong { color: var(--blue); display: block; font-size: 22px; }
.nodes-cards, .privacy-grid, .policy-grid, .device-grid, .protocol-grid, .process-steps, .risk-grid, .faq-grid, .related-grid, .about-grid { display: grid; gap: 18px; }
.nodes-cards .guide-card { border-left: 4px solid var(--blue); }
.privacy-protection-section {
    border-radius: var(--radius-xl);
    background: linear-gradient(180deg, #ffffff 0%, #f6f9ff 100%);
    border: 1px solid var(--line);
    padding: 28px;
}
.privacy-card h3, .policy-card h3, .protocol-card h3 { margin: 0 0 8px; }
.policy-card, .protocol-card { min-height: 100%; }
.device-showcase { display: grid; gap: 18px; }
.device-card { border-radius: 28px; padding: 22px; background: #fff; border: 1px solid var(--line); }
.device-card:nth-child(2) { background: #f7faff; }
.process-steps { counter-reset: step; }
.step-card { position: relative; padding-top: 26px; }
.step-card .num { display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; background: var(--blue); color: #fff; font-weight: 800; margin-bottom: 10px; }
.risk-card { border-left: 4px solid var(--blue); }
.risk-card strong { color: #0f172a; }
.faq-item h3 { margin: 0 0 8px; font-size: 19px; }
.faq-item p { color: var(--muted); margin: 0; }
.cta-section {
    margin: 54px auto 0;
    border-radius: var(--radius-xl);
    background: var(--gradient);
    color: #fff;
    padding: 42px 24px;
    text-align: center;
    overflow: hidden;
    position: relative;
}
.cta-section::before { content: ""; position: absolute; width: 280px; height: 280px; border-radius: 50%; background: rgba(255,255,255,.16); right: -80px; top: -100px; }
.cta-section h2 { margin: 0 0 10px; font-size: clamp(28px, 5vw, 42px); }
.cta-section p { color: rgba(255,255,255,.86); max-width: 680px; margin: 0 auto 22px; }

.page-hero { padding: 56px 0 32px; background: linear-gradient(180deg, #f7faff 0%, #fff 100%); }
.page-hero h1 { margin: 0 0 14px; font-size: clamp(32px, 7vw, 52px); line-height: 1.12; letter-spacing: -0.04em; }
.page-hero p { color: var(--muted); font-size: 18px; max-width: 760px; }
.content-layout { display: grid; gap: 24px; padding: 38px 0 66px; }
.article-body { display: grid; gap: 20px; }
.article-body h2 { margin: 0; font-size: 26px; }
.article-body p { color: #475569; }
.side-panel { display: grid; gap: 16px; align-self: start; }
.check-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
.check-list li { padding: 13px 14px; border-radius: 16px; border: 1px solid var(--line); background: #fff; color: #475569; }
.check-list li::before { content: "✓"; color: var(--blue); font-weight: 900; margin-right: 8px; }
.number-list { counter-reset: item; list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
.number-list li { background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 16px; }
.number-list strong { color: var(--text); display: block; }
.download-panel { text-align: center; background: linear-gradient(180deg, #ffffff, #f4f8ff); }
.download-panel h2 { margin: 0 0 10px; }
.download-panel p { color: var(--muted); }
.faq-list { display: grid; gap: 16px; }
.about-panel { background: linear-gradient(180deg, #fff, #f7faff); }

.site-footer { background: #111827; color: #d1d5db; padding-top: 46px; }
.footer-grid { display: grid; gap: 28px; }
.site-footer h3 { color: #fff; margin: 0 0 12px; }
.site-footer a { display: block; color: #cbd5e1; margin: 7px 0; }
.site-footer a:hover { color: #fff; }
.footer-brand { color: #fff; margin-bottom: 12px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); margin-top: 36px; padding: 18px; text-align: center; color: #9ca3af; }

@media (min-width: 680px) {
    .highlight-grid, .privacy-grid, .policy-grid, .protocol-grid, .faq-grid, .related-grid, .about-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .process-steps, .risk-grid, .device-grid, .nodes-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .speed-metrics { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 980px) {
    .nav-toggle-label { display: none; }
    .site-nav { position: static; display: flex; flex-direction: row; align-items: center; padding: 0; border: 0; border-radius: 0; box-shadow: none; background: transparent; gap: 2px; }
    .site-nav a { font-size: 14px; padding: 8px 10px; }
    .hero-inner { grid-template-columns: 1.05fr .95fr; padding: 94px 0 126px; }
    .highlight-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .vpn-connection-section, .high-speed-section, .global-nodes-section, .multi-device-section, .encryption-protocol-section, .feature-panel { grid-template-columns: 1fr 1fr; }
    .global-nodes-section .image-card, .multi-device-section .image-card { order: 2; }
    .privacy-protection-section { padding: 42px; }
    .privacy-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .policy-grid, .protocol-grid, .risk-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .process-steps { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .content-layout { grid-template-columns: minmax(0, 1fr) 320px; align-items: start; }
    .footer-grid { grid-template-columns: 1.4fr repeat(3, 1fr); }
    .section { padding: 76px 0; }
}

@media (min-width: 1180px) {
    .site-nav a { padding: 9px 12px; }
}

@media (max-width: 420px) {
    .container, .narrow-container, .hero-inner, .header-inner { width: min(100% - 24px, 1160px); }
    .feature-card, .image-card, .privacy-card, .policy-card, .protocol-card, .step-card, .risk-card, .faq-item, .guide-card, .tip-box, .download-panel, .about-panel { padding: 20px; }
    .floating-card { position: static; margin: 6px; display: inline-flex; }
    .hero-visual { min-height: auto; display: block; }
    .hero-phone { margin: 18px auto; }
    .download-btn { width: 100%; }
}