* {
    box-sizing: border-box;
}

:root {
    --brand-blue: #2980FE;
    --brand-blue-hover: #1768E8;
    --deep: #172033;
    --text: #364057;
    --muted: #697386;
    --line: #e5eaf3;
    --light: #f5f8ff;
    --soft: #eef4ff;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --radius: 24px;
    --shadow: 0 18px 48px rgba(30, 60, 120, 0.12);
}

body {
    margin: 0;
    color: var(--text);
    background: #ffffff;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    line-height: 1.75;
    overflow-x: hidden;
}

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

a {
    color: var(--brand-blue);
    text-decoration: none;
}

a:hover {
    color: var(--brand-blue-hover);
}

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 70px;
    gap: 18px;
}

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

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

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

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

.nav-trigger span {
    width: 18px;
    height: 2px;
    background: var(--deep);
    border-radius: 2px;
}

.site-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    display: none;
    flex-direction: column;
    padding: 12px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: var(--shadow);
}

.site-nav a {
    padding: 10px 12px;
    color: #253047;
    font-weight: 650;
    border-radius: 12px;
}

.site-nav a:hover {
    background: var(--soft);
    color: var(--brand-blue);
}

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

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 26px;
    border-radius: 999px;
    background: var(--brand-blue);
    color: #fff;
    font-weight: 760;
    box-shadow: 0 12px 26px rgba(41, 128, 254, 0.28);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    color: #fff;
    background: var(--brand-blue-hover);
    transform: translateY(-2px);
    box-shadow: 0 14px 30px rgba(23, 104, 232, 0.32);
}

.section {
    padding: 72px 0;
}

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

.section-title {
    max-width: 760px;
    margin-bottom: 30px;
}

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

.kicker,
.category-badge,
.card-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 12px;
    border-radius: 999px;
    color: var(--brand-blue);
    background: #e9f2ff;
    font-size: 13px;
    font-weight: 800;
}

h1,
h2,
h3 {
    color: var(--deep);
    line-height: 1.18;
    margin: 0 0 14px;
}

h1 {
    font-size: clamp(36px, 8vw, 64px);
    letter-spacing: -0.05em;
}

h2 {
    font-size: clamp(28px, 5vw, 42px);
    letter-spacing: -0.035em;
}

h3 {
    font-size: 20px;
}

p {
    margin: 0 0 16px;
}

.lead {
    font-size: 18px;
    color: var(--muted);
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    color: #fff;
    background: var(--gradient);
    padding: 70px 0 52px;
}

.vpn-network-hero::before,
.cta-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 12% 20%, rgba(255,255,255,.28), transparent 18%),
        radial-gradient(circle at 78% 32%, rgba(255,255,255,.20), transparent 20%),
        linear-gradient(135deg, transparent 0 38%, rgba(255,255,255,.13) 39% 40%, transparent 41% 100%);
    pointer-events: none;
}

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

.hero-copy h1,
.hero-copy p {
    color: #fff;
}

.hero-copy .lead {
    color: rgba(255,255,255,.88);
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 14px;
    margin: 24px 0 18px;
}

.hero-note {
    color: rgba(255,255,255,.82);
    font-size: 14px;
}

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

.hero-tags span,
.status-tags span,
.inline-tags span {
    display: inline-flex;
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.24);
    color: #fff;
    font-weight: 700;
    font-size: 13px;
}

.hero-visual {
    position: relative;
    min-height: 320px;
    display: grid;
    place-items: center;
}

.hero-visual .product-frame {
    width: min(430px, 82vw);
    padding: 18px;
    border-radius: 34px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.26);
    box-shadow: 0 28px 70px rgba(18, 28, 80, .28);
}

.floating-label {
    position: absolute;
    padding: 10px 13px;
    border-radius: 16px;
    background: rgba(255,255,255,.92);
    color: #253047;
    font-weight: 800;
    box-shadow: 0 14px 32px rgba(20, 34, 80, .18);
    font-size: 13px;
}

.floating-label.one { top: 20px; left: 4px; }
.floating-label.two { top: 34px; right: 0; }
.floating-label.three { bottom: 62px; left: 18px; }
.floating-label.four { bottom: 34px; right: 24px; }

.node-overview {
    margin-top: -26px;
    position: relative;
    z-index: 2;
}

.overview-grid,
.card-grid,
.risk-grid,
.policy-grid,
.faq-grid {
    display: grid;
    gap: 18px;
}

.node-card,
.feature-card,
.risk-card,
.policy-card,
.faq-item,
.side-card,
.step-card,
.help-box,
.note-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: 0 12px 32px rgba(30, 60, 120, 0.07);
}

.node-card {
    min-height: 188px;
}

.node-card a,
.feature-card a,
.risk-card a,
.step-card a,
.side-card a,
.text-link {
    font-weight: 800;
}

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

.media-panel,
.security-panel,
.speed-panel,
.tech-panel,
.device-panel,
.map-panel {
    position: relative;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 20px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.media-panel::after,
.map-panel::after,
.tech-panel::after {
    content: "";
    position: absolute;
    width: 220px;
    height: 220px;
    right: -90px;
    top: -90px;
    border-radius: 50%;
    background: rgba(41,128,254,.10);
}

.bullet-list,
.check-list {
    display: grid;
    gap: 10px;
    margin: 20px 0;
    padding: 0;
    list-style: none;
}

.bullet-list li,
.check-list li {
    position: relative;
    padding-left: 26px;
    color: var(--text);
}

.bullet-list li::before,
.check-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 10px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--brand-blue);
}

.global-nodes-section {
    padding: 34px;
    border-radius: 32px;
    background:
        radial-gradient(circle at 20% 30%, rgba(41,128,254,.10), transparent 24%),
        radial-gradient(circle at 80% 60%, rgba(123,78,241,.12), transparent 26%),
        #fff;
    border: 1px solid var(--line);
}

.map-panel {
    min-height: 300px;
}

.map-dots {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
    position: relative;
    z-index: 1;
}

.dot-card {
    padding: 14px;
    border-radius: 18px;
    background: #f7faff;
    border: 1px solid #dce8ff;
}

.dot-card strong {
    display: block;
    color: var(--deep);
}

.speed-lines {
    display: grid;
    gap: 12px;
    margin-top: 16px;
}

.speed-line {
    padding: 14px;
    border-radius: 18px;
    background: #f7faff;
    border: 1px solid #dce8ff;
}

.progress {
    height: 8px;
    margin-top: 10px;
    border-radius: 999px;
    background: #dfe9ff;
    overflow: hidden;
}

.progress span {
    display: block;
    height: 100%;
    border-radius: 999px;
    background: var(--brand-blue);
}

.privacy-board {
    display: grid;
    gap: 14px;
}

.privacy-item {
    padding: 18px;
    border-radius: 20px;
    background: #f7faff;
    border-left: 4px solid var(--brand-blue);
}

.policy-grid {
    grid-template-columns: 1fr;
}

.device-grid {
    display: grid;
    gap: 14px;
    grid-template-columns: 1fr;
}

.device-tile {
    padding: 18px;
    border-radius: 22px;
    background: #f7faff;
    border: 1px solid #dfe8f8;
}

.protocol-stack {
    display: grid;
    gap: 14px;
}

.protocol-item {
    display: flex;
    gap: 12px;
    align-items: flex-start;
    padding: 16px;
    border-radius: 20px;
    background: #f7faff;
    border: 1px solid #dfe8f8;
}

.protocol-item span {
    width: 34px;
    height: 34px;
    flex: 0 0 34px;
    border-radius: 12px;
    display: grid;
    place-items: center;
    background: var(--brand-blue);
    color: #fff;
    font-weight: 800;
}

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

.step-card {
    position: relative;
    padding-left: 76px;
}

.step-card::before {
    counter-increment: steps;
    content: counter(steps, decimal-leading-zero);
    position: absolute;
    left: 22px;
    top: 22px;
    width: 38px;
    height: 38px;
    border-radius: 14px;
    display: grid;
    place-items: center;
    color: #fff;
    background: var(--brand-blue);
    font-weight: 900;
}

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

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

.cta-section {
    position: relative;
    overflow: hidden;
    margin: 40px 0 0;
    padding: 66px 0;
    color: #fff;
    background: var(--gradient);
    text-align: center;
}

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

.cta-section .container {
    position: relative;
}

.cta-section .download-btn {
    background: var(--brand-blue);
}

.page-hero {
    padding: 62px 0 38px;
    background:
        radial-gradient(circle at 10% 0%, rgba(41,128,254,.12), transparent 28%),
        radial-gradient(circle at 82% 18%, rgba(184,77,218,.12), transparent 30%),
        #f7faff;
    border-bottom: 1px solid var(--line);
}

.page-hero .lead {
    max-width: 760px;
}

.content-layout {
    display: grid;
    gap: 24px;
    align-items: start;
}

.article-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 28px;
    padding: 24px;
    box-shadow: 0 14px 36px rgba(30,60,120,.08);
}

.article-panel h2 {
    font-size: 28px;
    margin-top: 22px;
}

.info-strip {
    display: grid;
    gap: 14px;
    margin: 22px 0;
}

.info-strip .info-item {
    padding: 16px;
    border-radius: 18px;
    border: 1px solid var(--line);
    background: #f8fbff;
}

.download-panel {
    margin-top: 24px;
    padding: 24px;
    border-radius: 28px;
    background: var(--soft);
    border: 1px solid #d8e7ff;
}

.download-steps {
    display: grid;
    gap: 14px;
    margin-top: 24px;
}

.download-step {
    padding: 18px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
}

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

.faq-list .faq-item {
    box-shadow: none;
}

.site-footer {
    background: #101828;
    color: #cbd5e1;
    padding: 54px 0 26px;
}

.site-footer a {
    display: block;
    color: #dce6f7;
    margin: 8px 0;
}

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

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

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

.footer-logo {
    color: #fff;
    margin-bottom: 14px;
}

.footer-bottom {
    margin-top: 30px;
    padding-top: 18px;
    border-top: 1px solid rgba(255,255,255,.12);
    display: flex;
    flex-direction: column;
    gap: 6px;
    color: #99a6ba;
    font-size: 14px;
}

@media (min-width: 680px) {
    .overview-grid,
    .card-grid,
    .risk-grid,
    .faq-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

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

@media (min-width: 940px) {
    .nav-trigger {
        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: 9px 10px;
    }

    .hero-inner,
    .split-section,
    .vpn-connection-section,
    .global-nodes-section,
    .high-speed-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section,
    .content-layout {
        grid-template-columns: 1.03fr .97fr;
    }

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

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

    .faq-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-grid {
        grid-template-columns: 1.4fr repeat(3, 1fr);
    }

    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
    }

    .vpn-network-hero {
        padding: 94px 0 76px;
    }

    .section {
        padding: 92px 0;
    }

    .article-panel {
        padding: 34px;
    }
}

@media (max-width: 430px) {
    .container {
        width: min(100% - 24px, 1120px);
    }

    .download-btn {
        width: 100%;
        padding: 0 20px;
    }

    .hero-actions .download-btn,
    .cta-section .download-btn {
        width: auto;
        min-width: 172px;
    }

    .floating-label {
        position: static;
        margin: 6px;
    }

    .hero-visual {
        min-height: auto;
    }

    .status-cloud {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        margin-top: 10px;
    }

    .map-dots {
        grid-template-columns: 1fr;
    }
}