* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #667085;
    --light: #f5f7fb;
    --lighter: #f8fbff;
    --border: #e5eaf2;
    --card: #ffffff;
    --shadow: 0 18px 48px rgba(31, 41, 55, 0.08);
}

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: 1.72;
    overflow-x: hidden;
}

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

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

p {
    margin: 0 0 14px;
    color: var(--muted);
}

h1, h2, h3 {
    margin: 0;
    line-height: 1.2;
    color: #111827;
}

.container {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(229, 234, 242, 0.9);
}

.header-inner {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.logo, .footer-logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #111827;
    letter-spacing: -0.02em;
}

.logo img, .footer-logo img {
    width: 38px;
    height: 38px;
    object-fit: cover;
    border-radius: 12px;
}

.site-nav {
    display: none;
    position: absolute;
    left: 14px;
    right: 14px;
    top: 72px;
    padding: 14px;
    border: 1px solid var(--border);
    background: #fff;
    border-radius: 20px;
    box-shadow: var(--shadow);
}

.site-nav a {
    display: block;
    padding: 11px 12px;
    color: #475467;
    font-weight: 650;
    border-radius: 12px;
}

.site-nav a:hover, .site-nav a.active {
    color: var(--blue);
    background: #eef5ff;
}

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

.mobile-nav-button {
    width: 42px;
    height: 42px;
    border: 1px solid var(--border);
    border-radius: 14px;
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    background: #fff;
}

.mobile-nav-button span {
    width: 18px;
    height: 2px;
    border-radius: 2px;
    background: #111827;
}

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

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    color: #fff;
    background: var(--blue);
    font-weight: 800;
    box-shadow: 0 12px 30px rgba(41, 128, 254, 0.26);
    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 34px rgba(23, 104, 232, 0.28);
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 72px 0 46px;
}

.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    inset: auto;
    border-radius: 50%;
    pointer-events: none;
}

.vpn-network-hero::before {
    width: 520px;
    height: 520px;
    right: -180px;
    top: -170px;
    background: rgba(255, 255, 255, 0.14);
}

.vpn-network-hero::after {
    width: 420px;
    height: 420px;
    left: -160px;
    bottom: -180px;
    background: rgba(255, 255, 255, 0.12);
}

.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 34px;
    align-items: center;
}

.hero-content h1 {
    font-size: clamp(34px, 9vw, 64px);
    color: #fff;
    letter-spacing: -0.05em;
    margin-bottom: 18px;
}

.hero-content p {
    max-width: 650px;
    color: rgba(255, 255, 255, 0.88);
    font-size: 17px;
}

.hero-tags, .floating-tags, .feature-tags, .panel-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.hero-tags {
    margin: 22px 0 26px;
}

.hero-tags span, .floating-tags span, .feature-tags span, .panel-tags span {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    font-weight: 700;
}

.hero-tags span {
    padding: 8px 12px;
    color: #fff;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.26);
}

.hero-visual {
    position: relative;
    min-height: 340px;
    padding: 20px;
    border-radius: 32px;
    background: rgba(255, 255, 255, 0.13);
    border: 1px solid rgba(255, 255, 255, 0.22);
    box-shadow: 0 26px 80px rgba(0, 0, 0, 0.16);
}

.hero-visual::before {
    content: "";
    position: absolute;
    inset: 28px;
    border-radius: 28px;
    background-image:
        radial-gradient(circle at 18% 30%, rgba(255,255,255,.85) 0 3px, transparent 4px),
        radial-gradient(circle at 76% 22%, rgba(255,255,255,.7) 0 3px, transparent 4px),
        radial-gradient(circle at 62% 76%, rgba(255,255,255,.72) 0 3px, transparent 4px),
        linear-gradient(120deg, transparent 10%, rgba(255,255,255,.22) 40%, transparent 70%);
    opacity: .72;
}

.hero-visual img {
    position: relative;
    z-index: 2;
    margin: 16px auto 0;
    max-height: 360px;
    object-fit: contain;
    filter: drop-shadow(0 26px 42px rgba(0, 0, 0, 0.22));
}

.status-card {
    position: absolute;
    z-index: 3;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 13px;
    border-radius: 999px;
    color: #111827;
    background: rgba(255, 255, 255, 0.93);
    box-shadow: 0 12px 30px rgba(17, 24, 39, 0.13);
    font-size: 13px;
    font-weight: 800;
}

.status-card::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--blue);
}

.status-one { left: 18px; top: 26px; }
.status-two { right: 18px; top: 76px; }
.status-three { left: 26px; bottom: 50px; }
.status-four { right: 26px; bottom: 24px; }

.section {
    padding: 72px 0;
}

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

.section-head {
    margin-bottom: 28px;
    max-width: 760px;
}

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

.section-kicker, .category-badge {
    display: inline-flex;
    align-items: center;
    margin-bottom: 12px;
    padding: 6px 12px;
    border-radius: 999px;
    color: var(--blue);
    background: #eef5ff;
    font-size: 13px;
    font-weight: 850;
}

.section h2 {
    font-size: clamp(26px, 5vw, 42px);
    letter-spacing: -0.04em;
    margin-bottom: 12px;
}

.node-overview {
    margin-top: -32px;
    position: relative;
    z-index: 3;
    padding-bottom: 40px;
}

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

.node-card, .feature-card, .risk-card, .faq-item, .step-card, .info-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 24px;
    box-shadow: 0 12px 34px rgba(17, 24, 39, 0.045);
}

.node-card {
    padding: 22px;
}

.node-card .tag {
    display: inline-flex;
    padding: 5px 10px;
    border-radius: 999px;
    background: #eef5ff;
    color: var(--blue);
    font-size: 12px;
    font-weight: 850;
    margin-bottom: 12px;
}

.node-card h3, .feature-card h3, .risk-card h3, .step-card h3, .info-card h3 {
    font-size: 19px;
    margin-bottom: 8px;
}

.text-link {
    display: inline-flex;
    margin-top: 6px;
    color: var(--blue);
    font-weight: 800;
}

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

.visual-panel {
    padding: 22px;
    border-radius: 32px;
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.visual-panel.gradient-glow {
    background: linear-gradient(135deg, #ffffff 0%, #f1f6ff 100%);
}

.feature-list {
    display: grid;
    gap: 12px;
    margin: 20px 0;
}

.feature-list li, .check-list li {
    list-style: none;
    padding-left: 28px;
    position: relative;
    color: #475467;
}

.feature-list li::before, .check-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: 0 0 0 5px #eaf3ff;
}

.global-nodes-section .map-panel {
    position: relative;
    padding: 28px;
    border-radius: 32px;
    overflow: hidden;
    background: #111827;
    min-height: 360px;
}

.map-panel::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 20% 38%, rgba(41,128,254,.95) 0 5px, transparent 6px),
        radial-gradient(circle at 68% 27%, rgba(184,77,218,.9) 0 5px, transparent 6px),
        radial-gradient(circle at 78% 70%, rgba(123,78,241,.9) 0 5px, transparent 6px),
        radial-gradient(circle at 38% 72%, rgba(41,128,254,.75) 0 5px, transparent 6px),
        linear-gradient(120deg, rgba(53,88,242,.25), transparent 46%, rgba(184,77,218,.22));
}

.map-panel::after {
    content: "";
    position: absolute;
    inset: 50px 38px;
    border: 1px dashed rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: rotate(-9deg);
}

.map-panel img {
    position: relative;
    z-index: 1;
    margin: 10px auto;
    max-height: 260px;
    object-fit: contain;
    filter: drop-shadow(0 24px 48px rgba(0,0,0,.28));
}

.map-card {
    position: relative;
    z-index: 2;
    max-width: 360px;
    padding: 18px;
    border-radius: 22px;
    background: rgba(255, 255, 255, 0.92);
    box-shadow: 0 18px 45px rgba(0,0,0,.18);
}

.speed-grid, .policy-grid, .risk-grid, .faq-grid, .related-grid {
    display: grid;
    gap: 16px;
}

.speed-card {
    padding: 20px;
    border-radius: 24px;
    background: #fff;
    border: 1px solid var(--border);
}

.speed-line {
    height: 10px;
    margin-top: 14px;
    border-radius: 999px;
    background: linear-gradient(90deg, #d7e7ff, #2980FE);
}

.privacy-panel, .protocol-panel, .cta-section, .page-hero {
    border-radius: 32px;
}

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

.panel-tags span, .feature-tags span {
    padding: 7px 11px;
    color: #344054;
    background: #f2f6fc;
    border: 1px solid var(--border);
    font-size: 13px;
}

.policy-grid .feature-card {
    padding: 22px;
}

.device-cards {
    display: grid;
    gap: 14px;
}

.device-card {
    padding: 18px;
    border-radius: 22px;
    background: #fff;
    border: 1px solid var(--border);
}

.protocol-panel {
    padding: 24px;
    background: linear-gradient(135deg, #f5f9ff 0%, #ffffff 100%);
    border: 1px solid var(--border);
}

.protocol-layer {
    margin-top: 12px;
    padding: 16px;
    border-radius: 18px;
    background: #fff;
    border: 1px solid var(--border);
}

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

.step-card {
    padding: 20px;
    position: relative;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 12px;
    color: #fff;
    background: var(--blue);
    font-weight: 900;
    margin-bottom: 12px;
}

.risk-card {
    padding: 20px;
    border-left: 5px solid var(--blue);
}

.risk-card strong {
    display: block;
    color: #344054;
    margin-top: 8px;
}

.faq-item {
    padding: 20px;
}

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

.cta-section {
    padding: 52px 24px;
    text-align: center;
    background: var(--gradient);
    color: #fff;
    overflow: hidden;
    position: relative;
}

.cta-section h2, .cta-section p {
    color: #fff;
}

.cta-section p {
    max-width: 620px;
    margin-left: auto;
    margin-right: auto;
    opacity: .9;
}

.page-hero {
    margin: 28px auto 0;
    padding: 46px 22px;
    background: linear-gradient(135deg, #f5f8ff 0%, #ffffff 100%);
    border: 1px solid var(--border);
}

.page-hero h1 {
    font-size: clamp(30px, 7vw, 50px);
    letter-spacing: -0.04em;
    margin-bottom: 12px;
}

.page-summary {
    max-width: 780px;
    font-size: 17px;
}

.article-section {
    padding: 42px 0 76px;
}

.article-layout {
    display: grid;
    gap: 22px;
}

.article-main, .article-side, .download-panel {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 28px;
    box-shadow: 0 12px 30px rgba(17,24,39,.045);
}

.article-main {
    padding: 24px;
}

.article-main h2 {
    font-size: 25px;
    margin: 22px 0 10px;
}

.article-main h2:first-child {
    margin-top: 0;
}

.article-side {
    padding: 22px;
    align-self: start;
}

.article-side h2, .article-side h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

.tip-box {
    padding: 18px;
    border-radius: 22px;
    background: #f6f9ff;
    border: 1px solid #dce9ff;
    margin: 18px 0;
}

.tip-box strong {
    display: block;
    color: #175cd3;
    margin-bottom: 5px;
}

.check-list {
    padding: 0;
    margin: 16px 0 0;
    display: grid;
    gap: 10px;
}

.download-panel {
    padding: 30px;
    text-align: center;
    margin-top: 22px;
    background: #f8fbff;
}

.download-panel h2 {
    margin-bottom: 8px;
}

.download-steps {
    counter-reset: item;
    padding: 0;
    margin: 20px 0;
    display: grid;
    gap: 12px;
}

.download-steps li {
    counter-increment: item;
    list-style: none;
    position: relative;
    padding: 16px 16px 16px 56px;
    border-radius: 18px;
    background: #fff;
    border: 1px solid var(--border);
    color: #475467;
}

.download-steps li::before {
    content: counter(item);
    position: absolute;
    left: 16px;
    top: 15px;
    width: 28px;
    height: 28px;
    border-radius: 10px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    background: var(--blue);
    font-weight: 900;
}

.about-values {
    display: grid;
    gap: 16px;
    margin-top: 22px;
}

.footer-grid {
    display: grid;
    gap: 26px;
    padding: 46px 0 30px;
}

.site-footer {
    background: #101828;
    color: #fff;
}

.site-footer p, .site-footer a {
    color: rgba(255,255,255,.72);
}

.site-footer h3 {
    color: #fff;
    font-size: 16px;
    margin-bottom: 10px;
}

.site-footer a {
    display: block;
    margin: 7px 0;
}

.site-footer a:hover {
    color: #fff;
}

.footer-logo span {
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.1);
    padding: 18px 16px;
    text-align: center;
    color: rgba(255,255,255,.62);
    font-size: 14px;
}

@media (min-width: 700px) {
    .node-overview-grid, .speed-grid, .policy-grid, .risk-grid, .faq-grid, .related-grid, .about-values {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    .process-steps {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 980px) {
    .mobile-nav-button {
        display: none;
    }
    .site-nav {
        position: static;
        display: flex;
        align-items: center;
        gap: 6px;
        padding: 0;
        border: 0;
        background: transparent;
        box-shadow: none;
    }
    .site-nav a {
        padding: 9px 11px;
        font-size: 14px;
    }
    .hero-grid,
    .split-section,
    .article-layout {
        grid-template-columns: minmax(0, 1.02fr) minmax(0, .98fr);
    }
    .article-layout {
        grid-template-columns: minmax(0, 1fr) 330px;
    }
    .node-overview-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
    .risk-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
    .process-steps {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
    .footer-grid {
        grid-template-columns: 1.4fr .8fr .8fr 1fr;
    }
    .section {
        padding: 88px 0;
    }
    .page-hero {
        padding: 58px;
    }
    .article-main {
        padding: 34px;
    }
}

@media (min-width: 1180px) {
    .site-nav a {
        padding: 9px 13px;
        font-size: 15px;
    }
}

@media (max-width: 420px) {
    .container {
        width: min(100% - 24px, 1120px);
    }
    .hero-visual {
        min-height: 300px;
        padding: 14px;
    }
    .status-card {
        font-size: 12px;
        padding: 8px 10px;
    }
    .status-two, .status-four {
        right: 10px;
    }
    .status-one, .status-three {
        left: 10px;
    }
    .download-btn {
        width: 100%;
    }
}