* {
    box-sizing: border-box;
}

:root {
    --gradient-main: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #637083;
    --light: #f5f7fb;
    --line: #e5eaf2;
    --card: #ffffff;
    --deep: #111827;
    --radius-lg: 28px;
    --radius-md: 20px;
    --shadow-soft: 0 18px 46px rgba(31, 41, 55, 0.10);
    --shadow-card: 0 12px 32px rgba(41, 128, 254, 0.10);
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    background: #ffffff;
    color: var(--text);
    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 16px;
}

h1,
h2,
h3 {
    margin: 0 0 16px;
    line-height: 1.25;
    color: var(--deep);
}

h1 {
    font-size: clamp(34px, 9vw, 62px);
    letter-spacing: -1.8px;
}

h2 {
    font-size: clamp(26px, 5vw, 42px);
}

h3 {
    font-size: 20px;
}

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(229, 234, 242, 0.86);
}

.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: #14213d;
    white-space: nowrap;
}

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

.main-nav {
    display: flex;
    align-items: center;
    gap: 4px;
}

.main-nav a {
    padding: 10px 12px;
    color: #435064;
    font-size: 15px;
    border-radius: 999px;
    transition: background .2s ease, color .2s ease;
}

.main-nav a:hover,
.main-nav a.active {
    background: #eef4ff;
    color: var(--blue);
}

.nav-toggle {
    display: none;
}

.nav-toggle-label {
    display: none;
    width: 42px;
    height: 42px;
    border: 1px solid var(--line);
    border-radius: 14px;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.nav-toggle-label span {
    width: 18px;
    height: 2px;
    background: #263348;
    border-radius: 2px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    background: var(--blue);
    color: #ffffff;
    border-radius: 999px;
    font-weight: 700;
    box-shadow: 0 12px 28px rgba(41, 128, 254, 0.24);
    transition: background .2s ease, transform .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    background: var(--blue-dark);
    transform: translateY(-2px);
    box-shadow: 0 16px 34px rgba(23, 104, 232, 0.28);
}

.text-link {
    display: inline-flex;
    color: var(--blue);
    font-weight: 700;
    align-items: center;
    gap: 6px;
}

.text-link::after {
    content: "→";
}

.badge,
.category-badge,
.tag {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    min-height: 30px;
    padding: 5px 12px;
    border-radius: 999px;
    background: #eef4ff;
    color: var(--blue);
    font-weight: 700;
    font-size: 13px;
}

.section {
    padding: 72px 0;
}

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

.section-heading {
    max-width: 760px;
    margin-bottom: 34px;
}

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

.section-heading p {
    color: var(--muted);
    font-size: 17px;
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient-main);
    color: #ffffff;
    padding: 72px 0 44px;
}

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

.vpn-network-hero::before {
    width: 520px;
    height: 520px;
    right: -170px;
    top: -170px;
    background: rgba(255, 255, 255, 0.18);
    filter: blur(6px);
}

.vpn-network-hero::after {
    width: 650px;
    height: 230px;
    left: 8%;
    bottom: -130px;
    background: rgba(255, 255, 255, 0.13);
    filter: blur(28px);
}

.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 38px;
    align-items: center;
}

.hero-copy h1,
.hero-copy h2,
.hero-copy h3 {
    color: #ffffff;
}

.hero-copy p {
    color: rgba(255, 255, 255, 0.88);
    font-size: 18px;
    max-width: 650px;
}

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

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

.hero-tags span {
    border: 1px solid rgba(255, 255, 255, .28);
    background: rgba(255, 255, 255, .12);
    color: #ffffff;
    border-radius: 999px;
    padding: 7px 12px;
    font-size: 14px;
}

.hero-visual {
    position: relative;
    min-height: 330px;
    display: grid;
    place-items: center;
}

.hero-device {
    width: min(430px, 92%);
    border-radius: 34px;
    box-shadow: 0 28px 80px rgba(12, 20, 48, 0.28);
    background: rgba(255,255,255,.12);
}

.network-lines {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 20% 30%, rgba(255,255,255,.52) 0 3px, transparent 4px),
        radial-gradient(circle at 70% 22%, rgba(255,255,255,.44) 0 3px, transparent 4px),
        radial-gradient(circle at 84% 72%, rgba(255,255,255,.35) 0 3px, transparent 4px),
        radial-gradient(circle at 32% 78%, rgba(255,255,255,.42) 0 3px, transparent 4px),
        linear-gradient(135deg, transparent 0 35%, rgba(255,255,255,.20) 36%, transparent 37% 100%),
        linear-gradient(35deg, transparent 0 42%, rgba(255,255,255,.16) 43%, transparent 44% 100%);
    opacity: .7;
}

.float-status {
    position: absolute;
    z-index: 2;
    background: rgba(255,255,255,.90);
    color: #1f2937;
    padding: 10px 14px;
    border-radius: 18px;
    box-shadow: 0 16px 40px rgba(13, 28, 69, 0.18);
    font-size: 14px;
    font-weight: 700;
}

.float-status.one { top: 22px; left: 2%; }
.float-status.two { top: 38px; right: 2%; }
.float-status.three { bottom: 42px; left: 6%; }
.float-status.four { bottom: 18px; right: 8%; }

.node-overview {
    margin-top: -34px;
    position: relative;
    z-index: 3;
}

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

.node-card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 22px;
    box-shadow: var(--shadow-card);
}

.node-card strong {
    display: block;
    color: var(--blue);
    margin-bottom: 8px;
}

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

.feature-split,
.vpn-connection-section,
.global-nodes-section,
.high-speed-section,
.privacy-protection-section,
.multi-device-section,
.encryption-protocol-section {
    display: grid;
    gap: 28px;
    align-items: center;
}

.feature-panel {
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 28px;
    box-shadow: var(--shadow-soft);
}

.feature-panel p,
.copy-block p {
    color: var(--muted);
    font-size: 16px;
}

.check-list,
.simple-list {
    display: grid;
    gap: 12px;
    margin: 20px 0;
    padding: 0;
    list-style: none;
}

.check-list li,
.simple-list li {
    position: relative;
    padding-left: 28px;
    color: #344055;
}

.check-list li::before,
.simple-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: 0 0 0 5px #eaf2ff;
}

.image-card {
    background: linear-gradient(145deg, #ffffff, #f2f6ff);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-soft);
}

.image-card img {
    border-radius: 22px;
    width: 100%;
}

.global-nodes-section {
    position: relative;
    border-radius: 34px;
    padding: 30px;
    background:
        radial-gradient(circle at 20% 25%, rgba(41,128,254,.16) 0 8px, transparent 9px),
        radial-gradient(circle at 76% 34%, rgba(123,78,241,.15) 0 8px, transparent 9px),
        radial-gradient(circle at 50% 74%, rgba(184,77,218,.13) 0 8px, transparent 9px),
        linear-gradient(135deg, #f5f8ff, #ffffff);
    border: 1px solid var(--line);
    overflow: hidden;
}

.global-nodes-section::before {
    content: "";
    position: absolute;
    inset: 18px;
    border-radius: 28px;
    background:
        linear-gradient(27deg, transparent 0 47%, rgba(41,128,254,.14) 48%, transparent 49%),
        linear-gradient(145deg, transparent 0 44%, rgba(123,78,241,.10) 45%, transparent 46%);
    pointer-events: none;
}

.global-nodes-section > * {
    position: relative;
    z-index: 1;
}

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

.speed-card,
.policy-card,
.protocol-card,
.step-card,
.risk-card,
.info-card {
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 20px;
    box-shadow: 0 10px 24px rgba(31, 41, 55, 0.06);
}

.speed-card span {
    display: inline-block;
    color: var(--blue);
    font-weight: 800;
    margin-bottom: 6px;
}

.privacy-panel {
    display: grid;
    gap: 16px;
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 24px;
    box-shadow: var(--shadow-soft);
}

.privacy-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.no-log-policy-section {
    display: grid;
    gap: 16px;
}

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

.device-grid,
.protocol-grid,
.faq-grid,
.risk-grid,
.related-grid {
    display: grid;
    gap: 16px;
}

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

.protocol-card {
    background: linear-gradient(180deg, #ffffff, #f7faff);
}

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

.step-card {
    counter-increment: step;
}

.step-number {
    width: 40px;
    height: 40px;
    display: inline-grid;
    place-items: center;
    border-radius: 14px;
    background: var(--blue);
    color: #fff;
    font-weight: 800;
    margin-bottom: 14px;
}

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

.risk-card strong {
    display: block;
    color: #1d2b46;
    margin-bottom: 6px;
}

.faq-item {
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 22px;
    box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}

.faq-item h3 {
    color: #17223a;
    font-size: 18px;
}

.cta-section {
    background: var(--gradient-main);
    color: #ffffff;
    text-align: center;
    border-radius: 34px;
    padding: 46px 22px;
    position: relative;
    overflow: hidden;
}

.cta-section h2 {
    color: #ffffff;
}

.cta-section p {
    color: rgba(255,255,255,.86);
    max-width: 680px;
    margin-left: auto;
    margin-right: auto;
}

.cta-section::before {
    content: "";
    position: absolute;
    width: 260px;
    height: 260px;
    border-radius: 999px;
    right: -80px;
    top: -110px;
    background: rgba(255,255,255,.16);
}

.page-hero {
    padding: 68px 0 44px;
    background: linear-gradient(180deg, #f6f9ff, #ffffff);
}

.page-hero-inner {
    max-width: 850px;
}

.page-hero p {
    color: var(--muted);
    font-size: 18px;
}

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

.article-card {
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: 28px;
    padding: 26px;
    box-shadow: var(--shadow-card);
}

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

.side-panel {
    background: #f7faff;
    border: 1px solid var(--line);
    border-radius: 24px;
    padding: 22px;
    position: sticky;
    top: 92px;
}

.side-panel a {
    display: block;
    padding: 10px 0;
    color: var(--blue);
    font-weight: 700;
    border-bottom: 1px solid #e4ebf6;
}

.side-panel a:last-child {
    border-bottom: 0;
}

.tip-box {
    background: #f5f9ff;
    border: 1px solid #dce9ff;
    border-radius: 22px;
    padding: 20px;
    margin: 22px 0;
}

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

.steps-list {
    display: grid;
    gap: 14px;
    margin: 24px 0;
    padding: 0;
    list-style: none;
}

.steps-list li {
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 18px;
}

.site-footer {
    background: #101827;
    color: #d4dceb;
    margin-top: 72px;
    padding-top: 56px;
}

.footer-grid {
    display: grid;
    gap: 26px;
}

.footer-grid h3 {
    color: #ffffff;
    font-size: 17px;
}

.footer-grid a {
    display: block;
    color: #c7d2e5;
    margin: 8px 0;
}

.footer-brand p {
    color: #aab6ca;
    max-width: 360px;
}

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

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.09);
    margin-top: 36px;
    padding: 20px;
    text-align: center;
    color: #94a3b8;
}

@media (max-width: 860px) {
    .header-inner {
        min-height: 66px;
    }

    .nav-toggle-label {
        display: inline-flex;
    }

    .main-nav {
        position: absolute;
        top: 66px;
        left: 14px;
        right: 14px;
        display: none;
        flex-direction: column;
        align-items: stretch;
        padding: 14px;
        background: #ffffff;
        border: 1px solid var(--line);
        border-radius: 22px;
        box-shadow: var(--shadow-soft);
    }

    .main-nav a {
        padding: 12px 14px;
    }

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

    .logo span {
        font-size: 15px;
    }

    .section {
        padding: 54px 0;
    }

    .float-status {
        font-size: 12px;
        padding: 8px 10px;
    }

    .page-hero {
        padding: 48px 0 32px;
    }

    .article-card {
        padding: 22px;
    }

    .download-btn {
        width: 100%;
    }

    .hero-actions .download-btn {
        width: auto;
    }
}

@media (min-width: 640px) {
    .node-card-grid,
    .device-grid,
    .protocol-grid,
    .related-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

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

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

    .no-log-policy-section {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

@media (min-width: 900px) {
    .hero-grid,
    .vpn-connection-section,
    .global-nodes-section,
    .high-speed-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section,
    .feature-split {
        grid-template-columns: 1.05fr .95fr;
    }

    .global-nodes-section {
        grid-template-columns: .95fr 1.05fr;
        padding: 44px;
    }

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

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

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

    .footer-grid {
        grid-template-columns: 1.5fr 1fr 1fr 1fr;
    }

    .content-layout {
        grid-template-columns: minmax(0, 1fr) 300px;
    }
}

@media (min-width: 1080px) {
    .hero-copy p {
        font-size: 19px;
    }

    .vpn-network-hero {
        padding: 92px 0 64px;
    }
}