* {
    box-sizing: border-box;
}

:root {
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --purple: #7B4EF1;
    --pink: #B84DDA;
    --navy: #172033;
    --text: #263247;
    --muted: #66728A;
    --light: #F4F7FB;
    --lighter: #F8FAFE;
    --line: #E6EBF3;
    --white: #FFFFFF;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --shadow: 0 16px 40px rgba(25, 38, 75, 0.08);
    --radius: 24px;
}

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: var(--white);
    line-height: 1.7;
    overflow-x: hidden;
}

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

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

p {
    margin: 0 0 16px;
}

h1, h2, h3 {
    color: var(--navy);
    line-height: 1.18;
    margin: 0 0 16px;
}

h1 {
    font-size: clamp(34px, 7vw, 64px);
    letter-spacing: -1.5px;
}

h2 {
    font-size: clamp(28px, 5vw, 44px);
    letter-spacing: -0.7px;
}

h3 {
    font-size: 20px;
}

.container {
    width: min(1120px, calc(100% - 40px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    border-bottom: 1px solid rgba(230, 235, 243, 0.85);
    backdrop-filter: blur(18px);
}

.header-inner {
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 800;
    color: var(--navy);
}

.brand img {
    width: 42px;
    height: 42px;
    border-radius: 13px;
    object-fit: cover;
}

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

.nav-toggle {
    width: 44px;
    height: 44px;
    border: 1px solid var(--line);
    border-radius: 14px;
    display: grid;
    place-items: center;
    gap: 0;
    cursor: pointer;
    background: var(--white);
}

.nav-toggle span {
    width: 20px;
    height: 2px;
    background: var(--navy);
    display: block;
    margin: 3px 0;
    border-radius: 999px;
}

.site-nav {
    display: none;
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    padding: 12px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: var(--shadow);
}

.nav-toggle-checkbox:checked ~ .site-nav {
    display: grid;
    gap: 6px;
}

.site-nav a {
    padding: 12px 14px;
    color: var(--muted);
    border-radius: 12px;
    font-weight: 600;
}

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

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    background: var(--blue);
    color: var(--white);
    font-weight: 800;
    box-shadow: 0 12px 26px 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 16px 32px rgba(23, 104, 232, 0.32);
}

.text-link {
    color: var(--blue);
    font-weight: 700;
}

.section {
    padding: 72px 0;
}

.section-soft {
    background: var(--lighter);
}

.section-head {
    margin-bottom: 30px;
    max-width: 780px;
}

.section-head.center {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}

.eyebrow,
.category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 14px;
    padding: 7px 13px;
    border-radius: 999px;
    background: #EEF5FF;
    color: var(--blue);
    font-size: 14px;
    font-weight: 800;
}

.eyebrow::before,
.category-badge::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--blue);
}

.hero-gradient,
.gradient-bg {
    background: var(--gradient);
    color: var(--white);
    position: relative;
    overflow: hidden;
}

.vpn-network-hero {
    min-height: 720px;
    padding: 74px 0 84px;
    background: var(--gradient);
    color: var(--white);
    position: relative;
    overflow: hidden;
}

.vpn-network-hero::before,
.vpn-network-hero::after,
.global-nodes-section::before {
    content: "";
    position: absolute;
    inset: auto;
    border-radius: 999px;
    pointer-events: none;
}

.vpn-network-hero::before {
    width: 580px;
    height: 580px;
    right: -180px;
    top: -160px;
    background: rgba(255, 255, 255, 0.13);
    filter: blur(6px);
}

.vpn-network-hero::after {
    width: 520px;
    height: 520px;
    left: -170px;
    bottom: -220px;
    background: rgba(41, 128, 254, 0.22);
}

.hero-grid {
    position: relative;
    z-index: 2;
    display: grid;
    gap: 38px;
    align-items: center;
}

.hero-copy h1,
.hero-copy h2,
.hero-copy p {
    color: var(--white);
}

.hero-copy p {
    color: rgba(255, 255, 255, 0.86);
    font-size: 18px;
    max-width: 660px;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 14px;
    flex-wrap: wrap;
    margin: 28px 0 22px;
}

.security-tags,
.hero-tags,
.tag-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.security-tags span,
.hero-tags span,
.tag-row span {
    display: inline-flex;
    align-items: center;
    min-height: 34px;
    padding: 7px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.24);
    color: rgba(255, 255, 255, 0.92);
    font-size: 13px;
    font-weight: 700;
}

.hero-visual {
    position: relative;
    min-height: 360px;
}

.hero-visual::before {
    content: "";
    position: absolute;
    inset: 9% 0 0 6%;
    background-image:
        radial-gradient(circle, rgba(255,255,255,0.75) 0 3px, transparent 4px),
        linear-gradient(120deg, rgba(255,255,255,0.22), rgba(255,255,255,0));
    background-size: 90px 90px, 100% 100%;
    border-radius: 32px;
    opacity: 0.55;
}

.hero-visual img {
    position: relative;
    z-index: 1;
    width: min(510px, 100%);
    margin: 0 auto;
    border-radius: 32px;
    box-shadow: 0 30px 80px rgba(18, 24, 54, 0.28);
}

.floating-card {
    position: absolute;
    z-index: 3;
    padding: 10px 14px;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.92);
    color: var(--navy);
    box-shadow: var(--shadow);
    font-weight: 800;
    font-size: 13px;
}

.floating-card:nth-of-type(1) { top: 28px; left: 4px; }
.floating-card:nth-of-type(2) { top: 90px; right: 0; }
.floating-card:nth-of-type(3) { bottom: 74px; left: 16px; }
.floating-card:nth-of-type(4) { bottom: 22px; right: 18px; }

.node-overview {
    margin-top: -44px;
    position: relative;
    z-index: 3;
}

.node-overview-grid {
    display: grid;
    gap: 16px;
}

.node-card,
.feature-card,
.info-card,
.risk-card,
.faq-item,
.step-card,
.protocol-card,
.sidebar-card,
.download-panel,
.about-card {
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.node-card {
    padding: 22px;
}

.node-card .label {
    display: inline-flex;
    margin-bottom: 12px;
    padding: 6px 10px;
    color: var(--blue);
    background: #EEF5FF;
    border-radius: 999px;
    font-weight: 800;
    font-size: 13px;
}

.node-card p {
    color: var(--muted);
}

.vpn-connection-section .split-panel,
.high-speed-section .split-panel,
.multi-device-section .split-panel,
.encryption-protocol-section .split-panel,
.global-nodes-section .split-panel {
    display: grid;
    gap: 30px;
    align-items: center;
}

.split-panel {
    display: grid;
    gap: 30px;
    align-items: center;
}

.image-panel {
    position: relative;
    padding: 18px;
    border-radius: 32px;
    background: linear-gradient(145deg, #EEF5FF, #FFFFFF);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.image-panel img {
    border-radius: 24px;
    width: 100%;
    object-fit: cover;
}

.feature-list,
.check-list,
.clean-list {
    display: grid;
    gap: 12px;
    padding: 0;
    margin: 22px 0;
    list-style: none;
}

.feature-list li,
.check-list li,
.clean-list li {
    position: relative;
    padding-left: 30px;
    color: var(--muted);
}

.feature-list li::before,
.check-list li::before,
.clean-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 9px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: inset 0 0 0 4px #DCEBFF;
}

.global-nodes-section {
    position: relative;
    overflow: hidden;
    background:
        radial-gradient(circle at 20% 20%, rgba(41, 128, 254, 0.12), transparent 26%),
        radial-gradient(circle at 80% 10%, rgba(123, 78, 241, 0.12), transparent 26%),
        var(--lighter);
}

.global-nodes-section::before {
    width: 520px;
    height: 520px;
    right: -180px;
    bottom: -220px;
    background: rgba(184, 77, 218, 0.10);
}

.node-map-card {
    position: relative;
    padding: 24px;
    border-radius: 32px;
    background:
        radial-gradient(circle, rgba(41,128,254,0.28) 0 4px, transparent 5px),
        linear-gradient(135deg, #FFFFFF, #F3F7FF);
    background-size: 80px 80px, 100% 100%;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.node-map-card img {
    border-radius: 26px;
    mix-blend-mode: multiply;
}

.node-line {
    position: absolute;
    height: 2px;
    background: linear-gradient(90deg, transparent, rgba(41,128,254,0.65), transparent);
    transform: rotate(-18deg);
}

.node-line.one { width: 72%; left: 10%; top: 34%; }
.node-line.two { width: 58%; right: 8%; top: 58%; transform: rotate(22deg); }

.speed-cards,
.policy-grid,
.device-grid,
.protocol-grid,
.risk-grid,
.faq-grid,
.related-grid,
.page-card-grid,
.about-grid {
    display: grid;
    gap: 18px;
}

.speed-card,
.policy-card,
.device-card,
.protocol-card,
.related-card,
.page-card {
    padding: 22px;
    border-radius: var(--radius);
    border: 1px solid var(--line);
    background: var(--white);
}

.speed-card strong {
    display: block;
    font-size: 26px;
    color: var(--blue);
    margin-bottom: 4px;
}

.privacy-protection-section .privacy-panel {
    display: grid;
    gap: 24px;
    align-items: center;
    padding: 24px;
    border-radius: 32px;
    background: var(--white);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.safety-panel {
    padding: 22px;
    border-radius: 24px;
    background: linear-gradient(145deg, #F7FAFF, #FFFFFF);
    border: 1px solid var(--line);
}

.safety-panel img {
    border-radius: 22px;
    margin-bottom: 18px;
}

.safety-panel .mini-list {
    display: grid;
    gap: 10px;
}

.safety-panel .mini-list span {
    padding: 10px 12px;
    border-radius: 14px;
    background: #EEF5FF;
    color: var(--blue);
    font-weight: 800;
}

.no-log-policy-section {
    background: var(--white);
}

.process-steps {
    display: grid;
    gap: 16px;
    counter-reset: step;
}

.step-card {
    padding: 22px;
    position: relative;
}

.step-number {
    width: 38px;
    height: 38px;
    border-radius: 14px;
    display: grid;
    place-items: center;
    background: var(--blue);
    color: var(--white);
    font-weight: 900;
    margin-bottom: 14px;
}

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

.risk-card .suggest {
    margin-top: 12px;
    padding: 12px;
    border-radius: 14px;
    background: #F4F8FF;
    color: var(--navy);
    font-weight: 700;
}

.faq-item {
    padding: 22px;
}

.faq-item h3 {
    font-size: 18px;
    margin-bottom: 10px;
}

.faq-list {
    display: grid;
    gap: 16px;
}

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

.cta-section h2,
.cta-section p {
    color: var(--white);
}

.cta-section p {
    color: rgba(255,255,255,0.84);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.page-hero {
    padding: 58px 0 42px;
    background:
        radial-gradient(circle at 80% 0, rgba(41,128,254,0.12), transparent 30%),
        linear-gradient(180deg, #F8FAFF 0%, #FFFFFF 100%);
    border-bottom: 1px solid var(--line);
}

.page-hero .summary {
    font-size: 18px;
    color: var(--muted);
    max-width: 760px;
}

.page-layout {
    display: grid;
    gap: 28px;
    padding: 56px 0 72px;
}

.article-content {
    max-width: 790px;
}

.article-content p {
    color: var(--muted);
    font-size: 16px;
}

.article-content h2 {
    font-size: clamp(24px, 4vw, 34px);
    margin-top: 36px;
}

.inline-panel {
    padding: 22px;
    border-radius: 24px;
    background: var(--lighter);
    border: 1px solid var(--line);
    margin: 24px 0;
}

.sidebar {
    display: grid;
    gap: 16px;
    align-content: start;
}

.sidebar-card {
    padding: 20px;
}

.sidebar-card h3 {
    font-size: 18px;
}

.sidebar-card a {
    display: block;
    color: var(--blue);
    font-weight: 700;
    margin-top: 8px;
}

.download-panel {
    padding: 26px;
    text-align: center;
    background: linear-gradient(145deg, #FFFFFF, #F4F8FF);
}

.download-steps {
    display: grid;
    gap: 14px;
    padding: 0;
    margin: 28px 0;
    list-style: none;
}

.download-steps li {
    padding: 16px;
    border-radius: 18px;
    background: var(--lighter);
    border: 1px solid var(--line);
}

.about-card {
    padding: 24px;
}

.site-footer {
    background: #111B2D;
    color: rgba(255,255,255,0.72);
    padding-top: 54px;
}

.footer-grid {
    display: grid;
    gap: 28px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--white);
    font-size: 22px;
    margin-bottom: 14px;
}

.footer-brand img {
    width: 42px;
    height: 42px;
    border-radius: 13px;
    object-fit: cover;
}

.site-footer h3 {
    color: var(--white);
    font-size: 18px;
}

.site-footer a {
    display: block;
    color: rgba(255,255,255,0.72);
    margin: 8px 0;
}

.site-footer a:hover {
    color: var(--white);
}

.footer-bottom {
    margin-top: 42px;
    padding: 18px 20px;
    text-align: center;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.footer-bottom p {
    margin: 0;
}

@media (min-width: 680px) {
    .node-overview-grid,
    .policy-grid,
    .device-grid,
    .protocol-grid,
    .risk-grid,
    .related-grid,
    .page-card-grid,
    .about-grid,
    .speed-cards {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

    .faq-grid {
        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;
        gap: 4px;
        padding: 0;
        background: transparent;
        border: 0;
        box-shadow: none;
    }

    .site-nav a {
        padding: 9px 12px;
        font-size: 15px;
    }

    .hero-grid,
    .split-panel,
    .vpn-connection-section .split-panel,
    .high-speed-section .split-panel,
    .multi-device-section .split-panel,
    .encryption-protocol-section .split-panel,
    .global-nodes-section .split-panel,
    .privacy-protection-section .privacy-panel,
    .page-layout {
        grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    }

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

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

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

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

    .footer-grid {
        grid-template-columns: 1.4fr 0.8fr 0.8fr 0.8fr;
    }

    .article-content {
        max-width: none;
    }

    .sidebar {
        position: sticky;
        top: 96px;
    }
}

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

    .header-inner {
        width: min(100% - 24px, 1180px);
    }

    .download-btn {
        width: 100%;
    }

    .section {
        padding: 54px 0;
    }

    .vpn-network-hero {
        padding: 54px 0 72px;
        min-height: auto;
    }

    .floating-card {
        font-size: 12px;
        padding: 8px 10px;
    }
}