* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1F2937;
    --muted: #667085;
    --soft: #F5F7FB;
    --soft-blue: #F3F7FF;
    --border: #E4E9F2;
    --white: #FFFFFF;
    --shadow: 0 20px 60px rgba(37, 71, 162, 0.10);
    --radius-lg: 28px;
    --radius-md: 22px;
    --radius-sm: 16px;
}

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: #F8FAFD;
    line-height: 1.7;
    overflow-x: hidden;
}

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

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

.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(228, 233, 242, 0.85);
}

.header-inner {
    max-width: 1180px;
    margin: 0 auto;
    padding: 12px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 800;
    white-space: nowrap;
}

.brand img {
    width: 40px;
    height: 40px;
    object-fit: contain;
    border-radius: 12px;
}

.nav-toggle-input {
    display: none;
}

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

.nav-toggle span {
    width: 20px;
    height: 2px;
    background: var(--text);
    border-radius: 999px;
}

.site-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 70px;
    display: none;
    padding: 14px;
    border: 1px solid var(--border);
    border-radius: 18px;
    background: #fff;
    box-shadow: var(--shadow);
}

.site-nav a {
    display: block;
    padding: 10px 12px;
    border-radius: 12px;
    color: #344054;
    font-size: 15px;
    font-weight: 650;
}

.site-nav a.active,
.site-nav a:hover {
    color: var(--blue);
    background: #EEF5FF;
}

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

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

.section {
    padding: 66px 0;
}

.section-title {
    margin: 0 0 14px;
    font-size: clamp(28px, 5vw, 44px);
    line-height: 1.15;
    letter-spacing: -0.04em;
}

.section-lead {
    margin: 0 0 24px;
    color: var(--muted);
    font-size: 16px;
}

.eyebrow,
.category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 14px;
    padding: 6px 12px;
    border-radius: 999px;
    background: #EDF5FF;
    color: var(--blue);
    font-size: 13px;
    font-weight: 750;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 34px 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 18px 38px rgba(23, 104, 232, 0.32);
}

.text-link {
    color: var(--blue);
    font-weight: 750;
}

.text-link:hover {
    color: var(--blue-dark);
}

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

.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    inset: auto;
    border-radius: 999px;
    filter: blur(12px);
    opacity: .35;
    pointer-events: none;
}

.vpn-network-hero::before {
    width: 360px;
    height: 360px;
    right: -140px;
    top: -80px;
    background: rgba(255, 255, 255, .55);
}

.vpn-network-hero::after {
    width: 300px;
    height: 300px;
    left: -120px;
    bottom: 40px;
    background: rgba(100, 210, 255, .42);
}

.hero-inner {
    position: relative;
    width: min(1180px, calc(100% - 36px));
    margin: 0 auto;
    padding: 72px 0 86px;
    display: grid;
    grid-template-columns: 1fr;
    gap: 42px;
    z-index: 1;
}

.hero-copy h1 {
    margin: 0 0 18px;
    font-size: clamp(36px, 8vw, 68px);
    line-height: 1.06;
    letter-spacing: -0.06em;
}

.hero-copy p {
    margin: 0 0 24px;
    max-width: 700px;
    color: rgba(255, 255, 255, .88);
    font-size: 17px;
}

.hero-tags,
.status-tags,
.inline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 20px 0 0;
}

.hero-tags span,
.status-tags span,
.inline-tags span {
    padding: 7px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, .15);
    color: #fff;
    font-size: 13px;
    font-weight: 700;
    border: 1px solid rgba(255, 255, 255, .22);
}

.inline-tags span {
    background: #EEF5FF;
    color: var(--blue);
    border-color: #D7E7FF;
}

.hero-visual {
    position: relative;
    min-height: 330px;
}

.network-orbit {
    position: absolute;
    inset: 6% 2% 2%;
    border-radius: var(--radius-lg);
    background:
        radial-gradient(circle at 20% 25%, rgba(255,255,255,.75) 0 4px, transparent 5px),
        radial-gradient(circle at 78% 28%, rgba(255,255,255,.75) 0 4px, transparent 5px),
        radial-gradient(circle at 62% 76%, rgba(255,255,255,.70) 0 4px, transparent 5px),
        linear-gradient(135deg, rgba(255,255,255,.20), rgba(255,255,255,.06));
    border: 1px solid rgba(255, 255, 255, .24);
    box-shadow: inset 0 0 0 1px rgba(255,255,255,.08);
}

.network-orbit::before,
.network-orbit::after {
    content: "";
    position: absolute;
    height: 1px;
    background: rgba(255,255,255,.35);
    transform-origin: left center;
}

.network-orbit::before {
    width: 72%;
    left: 18%;
    top: 28%;
    transform: rotate(17deg);
}

.network-orbit::after {
    width: 58%;
    left: 28%;
    top: 65%;
    transform: rotate(-28deg);
}

.hero-device {
    position: relative;
    margin: 24px auto 0;
    width: min(360px, 88%);
    padding: 18px;
    border-radius: 34px;
    background: rgba(255, 255, 255, .20);
    border: 1px solid rgba(255, 255, 255, .28);
    box-shadow: 0 30px 80px rgba(24, 25, 84, .22);
    backdrop-filter: blur(10px);
}

.hero-device img {
    border-radius: 24px;
    margin: 0 auto;
}

.status-card {
    position: relative;
    margin-top: 16px;
    padding: 12px 14px;
    border-radius: 18px;
    background: rgba(255, 255, 255, .92);
    color: var(--text);
    box-shadow: var(--shadow);
    font-size: 14px;
    font-weight: 760;
}

.status-card small {
    display: block;
    color: var(--muted);
    font-weight: 600;
}

.floating-card {
    display: none;
    position: absolute;
    min-width: 130px;
    padding: 10px 12px;
    border-radius: 16px;
    background: #fff;
    color: var(--text);
    box-shadow: var(--shadow);
    font-size: 13px;
    font-weight: 800;
}

.floating-card small {
    display: block;
    color: var(--muted);
    font-weight: 600;
}

.float-a { right: 0; top: 40px; }
.float-b { left: 0; bottom: 86px; }
.float-c { right: 20px; bottom: 28px; }

.node-overview {
    margin-top: -40px;
    position: relative;
    z-index: 3;
}

.node-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

.node-card,
.info-card,
.risk-card,
.faq-item,
.step-card,
.policy-card,
.device-card,
.tip-card,
.download-step,
.guide-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: 0 16px 40px rgba(31, 41, 55, .05);
}

.node-card {
    padding: 24px;
}

.node-card span {
    display: inline-flex;
    margin-bottom: 12px;
    padding: 5px 10px;
    border-radius: 999px;
    background: #EEF5FF;
    color: var(--blue);
    font-size: 12px;
    font-weight: 800;
}

.node-card h3,
.info-card h3,
.risk-card h3,
.step-card h3,
.policy-card h3,
.device-card h3,
.tip-card h3,
.guide-card h3 {
    margin: 0 0 10px;
    font-size: 20px;
}

.node-card p,
.info-card p,
.risk-card p,
.step-card p,
.policy-card p,
.device-card p,
.tip-card p,
.guide-card p,
.download-step p {
    margin: 0 0 14px;
    color: var(--muted);
}

.split-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 28px;
    align-items: center;
}

.image-panel {
    padding: 18px;
    border-radius: var(--radius-lg);
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.image-panel img {
    border-radius: 22px;
    margin: 0 auto;
}

.feature-list,
.clean-list {
    margin: 0 0 24px;
    padding: 0;
    list-style: none;
}

.feature-list li,
.clean-list li {
    position: relative;
    margin-bottom: 12px;
    padding-left: 26px;
    color: #3F4A5A;
}

.feature-list li::before,
.clean-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 10px;
    height: 10px;
    border-radius: 999px;
    background: var(--blue);
    box-shadow: 0 0 0 5px #E8F2FF;
}

.global-nodes-section {
    background:
        radial-gradient(circle at 18% 22%, rgba(41, 128, 254, .13), transparent 28%),
        radial-gradient(circle at 80% 54%, rgba(123, 78, 241, .11), transparent 30%),
        #FFFFFF;
}

.map-panel {
    position: relative;
    min-height: 310px;
    padding: 24px;
    overflow: hidden;
    border-radius: var(--radius-lg);
    background:
        linear-gradient(90deg, rgba(41,128,254,.06) 1px, transparent 1px),
        linear-gradient(0deg, rgba(41,128,254,.06) 1px, transparent 1px),
        #F7FAFF;
    background-size: 38px 38px;
    border: 1px solid #DDEAFF;
}

.map-panel img {
    width: min(420px, 86%);
    margin: 28px auto 0;
    border-radius: 24px;
}

.node-pin {
    position: absolute;
    width: 14px;
    height: 14px;
    border-radius: 999px;
    background: var(--blue);
    box-shadow: 0 0 0 8px rgba(41,128,254,.12);
}

.pin-1 { left: 22%; top: 26%; }
.pin-2 { right: 26%; top: 32%; }
.pin-3 { left: 44%; bottom: 22%; }
.pin-4 { right: 18%; bottom: 30%; }

.high-speed-section,
.multi-device-section,
.faq-preview,
.page-soft {
    background: var(--soft-blue);
}

.speed-grid,
.policy-grid,
.device-grid,
.risk-grid,
.faq-grid,
.download-steps,
.guide-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

.speed-meter {
    padding: 22px;
    border-radius: var(--radius-md);
    background: #fff;
    border: 1px solid var(--border);
}

.speed-line {
    height: 10px;
    border-radius: 999px;
    background: #E9EEF8;
    overflow: hidden;
    margin: 12px 0 8px;
}

.speed-line span {
    display: block;
    height: 100%;
    width: var(--w, 70%);
    border-radius: inherit;
    background: var(--gradient);
}

.privacy-panel,
.protocol-panel,
.safety-panel {
    padding: 26px;
    border-radius: var(--radius-lg);
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.privacy-border {
    padding: 18px;
    border-radius: 20px;
    background: linear-gradient(180deg, #F7FAFF, #FFFFFF);
    border: 1px solid #DDEAFF;
}

.policy-card,
.device-card,
.info-card,
.tip-card,
.guide-card {
    padding: 22px;
}

.policy-card {
    border-top: 4px solid var(--blue);
}

.protocol-stack {
    display: grid;
    gap: 12px;
}

.protocol-item {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 12px;
    padding: 14px;
    border-radius: 16px;
    background: #F7FAFF;
    border: 1px solid #E1EDFF;
}

.protocol-num,
.step-num {
    display: inline-flex;
    width: 32px;
    height: 32px;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 900;
}

.process-steps {
    display: grid;
    grid-template-columns: 1fr;
    gap: 14px;
    counter-reset: steps;
}

.step-card {
    padding: 22px;
}

.step-card .step-num {
    margin-bottom: 14px;
}

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

.risk-card strong {
    display: block;
    margin: 10px 0 2px;
}

.faq-item {
    padding: 22px;
}

.faq-item h3 {
    margin: 0 0 8px;
    font-size: 18px;
}

.faq-item p {
    margin: 0;
    color: var(--muted);
}

.cta-section {
    padding: 70px 0;
    color: #fff;
    background: var(--gradient);
    text-align: center;
}

.cta-section .section-inner {
    max-width: 820px;
}

.cta-section h2 {
    margin: 0 0 12px;
    font-size: clamp(28px, 6vw, 46px);
    line-height: 1.15;
}

.cta-section p {
    color: rgba(255,255,255,.86);
    margin: 0 auto 24px;
}

.cta-section .download-btn {
    background: #2980FE;
    color: #fff;
    border: 1px solid rgba(255,255,255,.24);
}

.page-hero {
    padding: 58px 0 36px;
    background:
        radial-gradient(circle at 12% 0%, rgba(41, 128, 254, .13), transparent 28%),
        radial-gradient(circle at 86% 15%, rgba(184, 77, 218, .12), transparent 34%),
        #FFFFFF;
    border-bottom: 1px solid var(--border);
}

.page-hero h1 {
    margin: 0 0 14px;
    font-size: clamp(34px, 7vw, 58px);
    line-height: 1.1;
    letter-spacing: -0.05em;
}

.page-hero p {
    margin: 0;
    max-width: 820px;
    color: var(--muted);
    font-size: 17px;
}

.page-content {
    padding: 54px 0 72px;
}

.reading-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 22px;
}

.article-card {
    padding: 26px;
    border-radius: var(--radius-lg);
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

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

.article-card p {
    color: #4B5563;
}

.side-card {
    padding: 22px;
    border-radius: var(--radius-md);
    background: #F7FAFF;
    border: 1px solid #DDEAFF;
}

.side-card h3 {
    margin: 0 0 12px;
}

.download-action {
    margin-top: 24px;
}

.checklist,
.number-list {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 12px;
}

.checklist li,
.number-list li {
    padding: 14px 16px;
    border-radius: 16px;
    background: #fff;
    border: 1px solid var(--border);
    color: #3F4A5A;
}

.number-list {
    counter-reset: item;
}

.number-list li {
    counter-increment: item;
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 12px;
}

.number-list li::before {
    content: counter(item);
    display: inline-flex;
    width: 28px;
    height: 28px;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    background: #EEF5FF;
    color: var(--blue);
    font-weight: 900;
}

.download-hero {
    padding: 60px 0 36px;
    background: var(--gradient);
    color: #fff;
}

.download-hero h1 {
    margin: 0 0 14px;
    font-size: clamp(34px, 8vw, 60px);
    line-height: 1.12;
}

.download-hero p {
    margin: 0 0 24px;
    max-width: 760px;
    color: rgba(255,255,255,.88);
}

.site-footer {
    background: #FFFFFF;
    border-top: 1px solid var(--border);
}

.footer-inner {
    width: min(1120px, calc(100% - 36px));
    margin: 0 auto;
    padding: 34px 0;
}

.footer-brand {
    display: flex;
    gap: 12px;
    align-items: center;
    margin-bottom: 18px;
}

.footer-brand img {
    width: 44px;
    height: 44px;
    border-radius: 13px;
}

.footer-brand p,
.footer-note {
    margin: 2px 0 0;
    color: var(--muted);
    font-size: 14px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 18px;
    margin-bottom: 16px;
}

.footer-links a {
    color: #475467;
    font-size: 14px;
    font-weight: 650;
}

.footer-links a:hover {
    color: var(--blue);
}

@media (min-width: 680px) {
    .node-grid,
    .speed-grid,
    .policy-grid,
    .device-grid,
    .risk-grid,
    .faq-grid,
    .download-steps,
    .guide-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

@media (min-width: 920px) {
    .nav-toggle {
        display: none;
    }

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

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

    .hero-inner {
        grid-template-columns: minmax(0, 1.02fr) minmax(360px, .86fr);
        align-items: center;
        padding: 90px 0 106px;
    }

    .floating-card {
        display: block;
    }

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

    .split-section {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 46px;
    }

    .reading-layout {
        grid-template-columns: minmax(0, 1fr) 310px;
        align-items: start;
    }

    .article-card {
        padding: 34px;
    }

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

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

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

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

@media (max-width: 420px) {
    .container,
    .section-inner,
    .footer-inner,
    .hero-inner {
        width: min(100% - 28px, 1120px);
    }

    .section {
        padding: 50px 0;
    }

    .download-btn {
        width: 100%;
    }

    .hero-copy .download-btn,
    .download-hero .download-btn {
        width: auto;
        min-width: 160px;
    }
}