* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    color: #1f2937;
    background: #f7f9fc;
    line-height: 1.75;
    overflow-x: hidden;
}

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

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

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid #e7ebf3;
    backdrop-filter: blur(18px);
}

.header-inner {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #111827;
    font-size: 18px;
}

.logo {
    width: 42px;
    height: 42px;
    border-radius: 14px;
    object-fit: cover;
    box-shadow: 0 8px 20px rgba(41, 128, 254, 0.16);
}

.nav-toggle {
    display: none;
}

.nav-toggle-label {
    width: 42px;
    height: 42px;
    border: 1px solid #d9e1ee;
    border-radius: 14px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    padding: 0 10px;
    cursor: pointer;
    background: #fff;
}

.nav-toggle-label span {
    height: 2px;
    background: #273449;
    border-radius: 2px;
}

.site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 74px;
    display: none;
    padding: 14px;
    background: #fff;
    border: 1px solid #e4eaf3;
    border-radius: 20px;
    box-shadow: 0 20px 50px rgba(26, 36, 56, 0.12);
}

.nav-toggle:checked ~ .site-nav {
    display: grid;
    gap: 8px;
}

.site-nav a {
    color: #4b5563;
    padding: 10px 12px;
    border-radius: 12px;
    font-weight: 650;
    font-size: 14px;
}

.site-nav a:hover,
.site-nav a.active {
    color: #2980FE;
    background: #eef5ff;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 46px;
    padding: 0 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #fff;
    font-weight: 800;
    letter-spacing: 0.02em;
    box-shadow: 0 12px 30px rgba(41, 128, 254, 0.28);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 16px 34px rgba(23, 104, 232, 0.32);
}

.text-link {
    color: #2980FE;
    font-weight: 750;
}

.text-link:hover {
    color: #1768E8;
}

.badge,
.page-badge {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 6px 12px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 760;
    color: #2980FE;
    background: #eef5ff;
    border: 1px solid #d8e7ff;
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    color: #fff;
}

.vpn-network-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 15% 20%, rgba(255,255,255,0.32), transparent 26%),
        radial-gradient(circle at 80% 30%, rgba(255,255,255,0.22), transparent 20%),
        linear-gradient(135deg, transparent 0 30%, rgba(255,255,255,0.1) 30% 31%, transparent 31% 55%, rgba(255,255,255,0.08) 55% 56%, transparent 56%);
    opacity: 0.85;
}

.hero-inner {
    position: relative;
    z-index: 1;
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    padding: 64px 0 78px;
    display: grid;
    gap: 36px;
}

.hero-copy {
    display: grid;
    gap: 18px;
    align-content: center;
}

.hero-copy h1 {
    margin: 0;
    font-size: clamp(36px, 8vw, 68px);
    line-height: 1.08;
    letter-spacing: -0.05em;
}

.hero-copy p {
    margin: 0;
    max-width: 660px;
    color: rgba(255,255,255,0.88);
    font-size: 17px;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-note {
    font-size: 13px;
    color: rgba(255,255,255,0.8);
}

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

.security-tags span,
.hero-status-tags span {
    padding: 7px 12px;
    border-radius: 999px;
    color: rgba(255,255,255,0.92);
    background: rgba(255,255,255,0.15);
    border: 1px solid rgba(255,255,255,0.24);
    backdrop-filter: blur(8px);
    font-size: 13px;
    font-weight: 650;
}

.hero-visual {
    position: relative;
    min-height: 340px;
    display: grid;
    place-items: center;
}

.hero-visual::before {
    content: "";
    position: absolute;
    width: 82%;
    aspect-ratio: 1;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.22);
    background: radial-gradient(circle, rgba(255,255,255,0.16), rgba(255,255,255,0.02) 58%, transparent 60%);
}

.hero-device {
    position: relative;
    width: min(360px, 86vw);
    border-radius: 32px;
    padding: 16px;
    background: rgba(255,255,255,0.18);
    border: 1px solid rgba(255,255,255,0.28);
    box-shadow: 0 26px 80px rgba(20, 28, 78, 0.32);
    backdrop-filter: blur(16px);
}

.hero-device img {
    border-radius: 26px;
    box-shadow: 0 18px 42px rgba(16, 24, 40, 0.26);
}

.float-card {
    position: absolute;
    z-index: 2;
    background: rgba(255,255,255,0.94);
    color: #273449;
    border-radius: 16px;
    padding: 10px 14px;
    border: 1px solid rgba(255,255,255,0.7);
    box-shadow: 0 14px 34px rgba(19, 34, 76, 0.18);
    font-size: 13px;
    font-weight: 780;
}

.float-card small {
    display: block;
    color: #6b7280;
    font-weight: 650;
}

.float-a { left: 2%; top: 14%; }
.float-b { right: 0; top: 28%; }
.float-c { left: 8%; bottom: 20%; }
.float-d { right: 8%; bottom: 10%; }

.section {
    padding: 64px 0;
}

.section-soft {
    background: #eef4fb;
}

.section-title {
    max-width: 780px;
    margin-bottom: 28px;
}

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

.section-title h2,
.page-hero h1,
.article-content h2 {
    margin: 10px 0 12px;
    color: #111827;
    line-height: 1.18;
    letter-spacing: -0.03em;
}

.section-title h2 {
    font-size: clamp(28px, 5vw, 42px);
}

.section-title p,
.page-hero p,
.card p,
.feature-copy p,
.article-content p,
.faq-item p {
    color: #5d6678;
}

.node-overview {
    margin-top: -34px;
    position: relative;
    z-index: 4;
}

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

.node-card,
.card,
.info-card,
.step-card,
.risk-card,
.faq-item {
    background: #fff;
    border: 1px solid #e4eaf3;
    border-radius: 24px;
    box-shadow: 0 12px 30px rgba(38, 50, 76, 0.06);
}

.node-card {
    padding: 22px;
}

.node-card .tag {
    display: inline-flex;
    margin-bottom: 12px;
    padding: 5px 10px;
    border-radius: 999px;
    color: #2980FE;
    background: #eef5ff;
    font-weight: 800;
    font-size: 12px;
}

.node-card h3,
.card h3,
.info-card h3,
.step-card h3,
.risk-card h3,
.faq-item h3 {
    margin: 0 0 8px;
    color: #172033;
}

.node-card p,
.card p,
.info-card p,
.step-card p,
.risk-card p {
    margin: 0 0 12px;
}

.feature-grid,
.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-copy {
    display: grid;
    gap: 16px;
}

.feature-copy h2 {
    margin: 0;
    font-size: clamp(28px, 5vw, 42px);
    line-height: 1.2;
    letter-spacing: -0.03em;
}

.feature-copy p {
    margin: 0;
}

.feature-points {
    display: grid;
    gap: 12px;
    margin: 0;
    padding: 0;
    list-style: none;
}

.feature-points li {
    padding: 12px 14px;
    border-radius: 16px;
    background: #f5f8fc;
    border: 1px solid #e6ecf5;
    color: #354156;
}

.image-panel {
    position: relative;
    padding: 18px;
    border-radius: 32px;
    background: #fff;
    border: 1px solid #e4eaf3;
    box-shadow: 0 18px 48px rgba(31, 41, 55, 0.08);
}

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

.map-panel {
    position: relative;
    min-height: 320px;
    padding: 20px;
    border-radius: 32px;
    background:
        radial-gradient(circle at 25% 30%, rgba(41,128,254,0.18), transparent 20%),
        radial-gradient(circle at 70% 55%, rgba(123,78,241,0.18), transparent 24%),
        linear-gradient(135deg, #ffffff, #eef5ff);
    border: 1px solid #dfe8f5;
    overflow: hidden;
}

.map-panel::after {
    content: "";
    position: absolute;
    inset: 24px;
    border-radius: 28px;
    background-image:
        linear-gradient(90deg, rgba(41,128,254,0.12) 1px, transparent 1px),
        linear-gradient(rgba(41,128,254,0.12) 1px, transparent 1px);
    background-size: 42px 42px;
}

.map-panel img {
    position: relative;
    z-index: 1;
    border-radius: 26px;
    margin-top: 18px;
}

.node-labels {
    position: relative;
    z-index: 2;
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.node-labels span {
    background: #fff;
    color: #2980FE;
    border: 1px solid #d9e8ff;
    border-radius: 999px;
    padding: 7px 12px;
    font-size: 13px;
    font-weight: 750;
}

.speed-cards,
.no-log-policy-section,
.device-cards,
.protocol-grid,
.risk-grid,
.faq-grid,
.article-grid,
.related-grid {
    display: grid;
    gap: 16px;
}

.speed-card,
.device-card,
.protocol-card {
    padding: 18px;
    border-radius: 22px;
    background: #fff;
    border: 1px solid #e4eaf3;
}

.speed-line {
    height: 8px;
    border-radius: 999px;
    background: linear-gradient(90deg, #2980FE, #7B4EF1, #B84DDA);
    margin: 12px 0;
}

.privacy-panel,
.safety-panel {
    border-radius: 30px;
    padding: 24px;
    background: #fff;
    border: 1px solid #e4eaf3;
    box-shadow: 0 18px 44px rgba(31, 41, 55, 0.07);
}

.privacy-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 16px;
}

.privacy-tags span {
    border-radius: 999px;
    padding: 7px 12px;
    color: #2980FE;
    background: #eef5ff;
    border: 1px solid #d8e7ff;
    font-weight: 700;
    font-size: 13px;
}

.card,
.info-card,
.step-card,
.risk-card,
.faq-item {
    padding: 22px;
}

.no-log-policy-section .info-card {
    border-top: 4px solid #2980FE;
}

.process-steps {
    display: grid;
    gap: 14px;
    counter-reset: steps;
}

.step-card {
    position: relative;
    padding-left: 68px;
}

.step-card::before {
    counter-increment: steps;
    content: counter(steps);
    position: absolute;
    left: 22px;
    top: 24px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    color: #fff;
    background: #2980FE;
    font-weight: 800;
}

.risk-card {
    border-left: 4px solid #2980FE;
}

.risk-card strong {
    color: #111827;
}

.cta-section {
    background: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    color: #fff;
    text-align: center;
    border-radius: 34px;
    padding: 46px 24px;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 20%, rgba(255,255,255,0.28), transparent 28%),
                radial-gradient(circle at 80% 70%, rgba(255,255,255,0.18), transparent 24%);
}

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

.cta-section h2 {
    margin: 0 0 12px;
    font-size: clamp(28px, 5vw, 42px);
    letter-spacing: -0.03em;
}

.cta-section p {
    margin: 0 auto 22px;
    max-width: 720px;
    color: rgba(255,255,255,0.86);
}

.page-hero {
    padding: 54px 0 34px;
    background: linear-gradient(180deg, #f7f9fc 0%, #eef4fb 100%);
}

.page-hero .container {
    display: grid;
    gap: 12px;
    max-width: 960px;
}

.page-hero h1 {
    font-size: clamp(32px, 6vw, 52px);
}

.article-shell {
    padding: 42px 0 70px;
}

.article-layout {
    display: grid;
    gap: 24px;
}

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

.article-content section,
.article-aside,
.download-panel {
    background: #fff;
    border: 1px solid #e4eaf3;
    border-radius: 26px;
    padding: 24px;
    box-shadow: 0 12px 32px rgba(38, 50, 76, 0.05);
}

.article-content h2 {
    font-size: 24px;
}

.article-content ul,
.article-content ol {
    margin: 0;
    padding-left: 20px;
    color: #4b5563;
}

.article-aside {
    display: grid;
    gap: 14px;
    align-content: start;
}

.article-aside a {
    padding: 10px 12px;
    border-radius: 14px;
    background: #f5f8fc;
    color: #354156;
    font-weight: 700;
}

.article-aside a:hover {
    background: #eef5ff;
    color: #2980FE;
}

.notice-box {
    padding: 18px;
    border-radius: 20px;
    background: #f5f8fc;
    border: 1px solid #e1e8f2;
}

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

.check-list li {
    padding: 12px 14px;
    border-radius: 16px;
    background: #f7faff;
    border: 1px solid #e3ecfb;
}

.download-panel {
    text-align: center;
}

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

.faq-item h2,
.faq-item h3 {
    font-size: 20px;
}

.site-footer {
    background: #111827;
    color: #d1d5db;
    padding-top: 48px;
}

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

.footer-brand p {
    color: #aeb7c7;
    margin: 12px 0 0;
}

.footer-logo {
    color: #fff;
    font-size: 20px;
    font-weight: 850;
}

.site-footer h3 {
    margin: 0 0 12px;
    color: #fff;
    font-size: 16px;
}

.site-footer a {
    display: block;
    color: #aeb7c7;
    margin: 8px 0;
}

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

.footer-bottom {
    margin-top: 34px;
    padding: 18px;
    border-top: 1px solid rgba(255,255,255,0.1);
    text-align: center;
    color: #9ca3af;
    font-size: 13px;
}

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

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

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

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

    .hero-inner {
        grid-template-columns: 1.05fr 0.95fr;
        padding: 92px 0 104px;
    }

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

    .vpn-connection-section,
    .global-nodes-section,
    .high-speed-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section,
    .feature-grid {
        grid-template-columns: 1fr 1fr;
    }

    .global-nodes-section .feature-copy,
    .privacy-protection-section .feature-copy {
        order: 0;
    }

    .global-nodes-section .map-panel,
    .privacy-protection-section .privacy-panel {
        order: 1;
    }

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

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

    .article-layout {
        grid-template-columns: minmax(0, 1fr) 300px;
        align-items: start;
    }

    .article-aside {
        position: sticky;
        top: 94px;
    }

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

@media (max-width: 520px) {
    .container {
        width: min(100% - 24px, 1120px);
    }

    .header-inner {
        width: min(100% - 20px, 1180px);
    }

    .site-nav {
        left: 10px;
        right: 10px;
    }

    .section {
        padding: 48px 0;
    }

    .hero-inner {
        padding: 48px 0 68px;
    }

    .hero-actions {
        align-items: stretch;
        flex-direction: column;
    }

    .download-btn {
        width: 100%;
    }

    .float-card {
        position: static;
        margin: 8px 0;
        width: fit-content;
    }

    .hero-status-tags {
        margin-top: 12px;
    }

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

    .step-card {
        padding-left: 58px;
    }

    .article-content section,
    .article-aside,
    .download-panel {
        padding: 20px;
        border-radius: 22px;
    }
}