* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
    color: #263244;
    background: #f6f8fc;
    line-height: 1.72;
    overflow-x: hidden;
}

a {
    color: #2980FE;
    text-decoration: none;
}

a:hover {
    color: #1768E8;
}

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(222, 228, 238, 0.82);
}

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

.header-inner {
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: #172033;
    font-weight: 800;
    letter-spacing: -0.02em;
}

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

.nav-toggle {
    border: 0;
    background: #eef3ff;
    width: 44px;
    height: 44px;
    border-radius: 14px;
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
}

.nav-toggle span {
    width: 18px;
    height: 2px;
    background: #263244;
    border-radius: 999px;
}

.main-nav {
    display: none;
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    padding: 14px;
    background: #fff;
    border: 1px solid #dfe6f2;
    border-radius: 22px;
    box-shadow: 0 18px 42px rgba(24, 38, 72, 0.12);
    flex-direction: column;
    gap: 4px;
}

.main-nav.is-open {
    display: flex;
}

.main-nav a {
    color: #405066;
    font-size: 14px;
    font-weight: 700;
    padding: 10px 12px;
    border-radius: 14px;
}

.main-nav a:hover,
.main-nav a.active {
    background: #eef4ff;
    color: #1768E8;
}

.site-main {
    min-height: 70vh;
}

.section,
.page-section {
    padding: 56px 0;
}

.section-soft {
    background: #eef3fa;
}

.section-title {
    max-width: 760px;
    margin: 0 auto 28px;
    text-align: center;
}

.section-title.align-left {
    text-align: left;
    margin-left: 0;
}

.eyebrow,
.category-badge {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    color: #1768E8;
    background: #eaf2ff;
    border: 1px solid #d3e4ff;
    padding: 6px 12px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 800;
    margin-bottom: 12px;
}

h1,
h2,
h3 {
    margin: 0;
    color: #172033;
    letter-spacing: -0.04em;
    line-height: 1.18;
}

h1 {
    font-size: clamp(34px, 8vw, 62px);
}

h2 {
    font-size: clamp(26px, 5vw, 40px);
}

h3 {
    font-size: 20px;
}

p {
    margin: 0;
    color: #5d6a7d;
}

.muted {
    color: #778399;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 28px rgba(41, 128, 254, 0.24);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    color: #fff;
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 18px 34px rgba(23, 104, 232, 0.28);
}

.text-link {
    font-weight: 800;
}

.vpn-saas-hero {
    position: relative;
    padding: 48px 0 64px;
    background: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    overflow: hidden;
}

.vpn-saas-hero::after {
    content: "";
    position: absolute;
    inset: auto -10% -1px -10%;
    height: 92px;
    background: #f6f8fc;
    clip-path: polygon(0 62%, 100% 0, 100% 100%, 0 100%);
}

.hero-inner {
    position: relative;
    z-index: 1;
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    display: grid;
    gap: 34px;
    align-items: center;
}

.hero-copy {
    color: #fff;
}

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

.hero-copy p {
    margin-top: 18px;
    max-width: 650px;
    opacity: 0.92;
    font-size: 18px;
}

.hero-actions {
    margin-top: 26px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 14px;
}

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

.hero-tags {
    margin-top: 22px;
}

.hero-tags span,
.inline-tags span,
.visual-tag {
    padding: 8px 12px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 800;
}

.hero-tags span {
    color: #fff;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.24);
}

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

.product-frame {
    position: relative;
    padding: 24px;
    border-radius: 36px;
    background: rgba(255, 255, 255, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.26);
    box-shadow: 0 30px 70px rgba(18, 25, 72, 0.26);
}

.product-frame img {
    margin: 0 auto;
    border-radius: 30px;
}

.visual-tag {
    position: absolute;
    color: #23314c;
    background: rgba(255, 255, 255, 0.94);
    border: 1px solid rgba(232, 236, 246, 0.9);
    box-shadow: 0 12px 30px rgba(23, 36, 75, 0.16);
}

.visual-tag.one { top: 18px; left: 8px; }
.visual-tag.two { top: 72px; right: 0; }
.visual-tag.three { bottom: 72px; left: 0; }
.visual-tag.four { bottom: 18px; right: 14px; }

.product-highlights {
    margin-top: -42px;
    position: relative;
    z-index: 2;
}

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

.highlight-card {
    background: #fff;
    border: 1px solid #e3e9f4;
    border-radius: 26px;
    padding: 22px;
    box-shadow: 0 14px 36px rgba(31, 45, 84, 0.08);
}

.highlight-card .tag {
    display: inline-flex;
    color: #2980FE;
    background: #ecf5ff;
    padding: 5px 10px;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 800;
    margin-bottom: 12px;
}

.highlight-card p {
    margin: 12px 0 14px;
}

.split-section,
.feature-split {
    display: grid;
    gap: 24px;
    align-items: center;
}

.feature-panel,
.image-panel,
.privacy-panel,
.tech-panel,
.article-card,
.download-card,
.faq-card {
    background: #fff;
    border: 1px solid #e2e8f3;
    border-radius: 32px;
    box-shadow: 0 16px 42px rgba(33, 48, 82, 0.07);
}

.feature-panel {
    padding: 26px;
}

.feature-panel p {
    margin-top: 14px;
}

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

.feature-list li {
    position: relative;
    padding-left: 24px;
    color: #405066;
}

.feature-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.78em;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: #2980FE;
}

.image-panel {
    padding: 18px;
    background: linear-gradient(180deg, #ffffff 0%, #f1f5ff 100%);
}

.image-panel img {
    border-radius: 26px;
    width: 100%;
    object-fit: cover;
}

.info-row {
    display: grid;
    gap: 14px;
    margin-top: 18px;
}

.mini-card {
    padding: 18px;
    border-radius: 24px;
    background: #f7f9fd;
    border: 1px solid #e5ebf4;
}

.mini-card h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.privacy-protection-section {
    background: radial-gradient(circle at 20% 0%, #eaf1ff 0, transparent 36%), #f6f8fc;
}

.privacy-panel {
    padding: 24px;
    display: grid;
    gap: 18px;
}

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

.privacy-card,
.policy-card,
.device-card,
.protocol-card,
.risk-card,
.related-card,
.check-card,
.step-card {
    background: #fff;
    border: 1px solid #e2e8f3;
    border-radius: 26px;
    padding: 20px;
}

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

.policy-card,
.protocol-card {
    background: #f8fbff;
}

.device-card {
    background: linear-gradient(180deg, #ffffff, #f4f7ff);
}

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

.step-card {
    position: relative;
}

.step-number {
    width: 40px;
    height: 40px;
    border-radius: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: #eaf2ff;
    color: #1768E8;
    font-weight: 900;
    margin-bottom: 12px;
}

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

.faq-item {
    background: #fff;
    border: 1px solid #e2e8f3;
    border-radius: 26px;
    padding: 22px;
}

.cta-section {
    padding: 58px 0;
}

.cta-panel {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    padding: 36px 24px;
    text-align: center;
    color: #fff;
    border-radius: 36px;
    background: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    box-shadow: 0 24px 60px rgba(70, 78, 190, 0.22);
}

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

.cta-panel p {
    max-width: 720px;
    margin: 14px auto 24px;
    opacity: 0.92;
}

.article-hero {
    padding: 54px 0 28px;
    background: linear-gradient(180deg, #eef4ff 0%, #f6f8fc 100%);
}

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

.article-card {
    padding: 26px;
}

.article-card p + p {
    margin-top: 16px;
}

.article-card h2 {
    margin-top: 26px;
    margin-bottom: 12px;
    font-size: clamp(23px, 4vw, 32px);
}

.side-panel {
    background: #fff;
    border: 1px solid #e2e8f3;
    border-radius: 28px;
    padding: 22px;
    position: sticky;
    top: 92px;
}

.side-panel h3 {
    margin-bottom: 10px;
}

.side-panel ul {
    margin: 14px 0 0;
    padding-left: 18px;
    color: #5d6a7d;
}

.page-cta {
    margin-top: 26px;
    padding-top: 22px;
    border-top: 1px solid #e4eaf3;
}

.download-card {
    padding: 28px;
}

.download-steps {
    display: grid;
    gap: 14px;
    margin: 26px 0;
}

.download-step {
    display: flex;
    gap: 14px;
    padding: 16px;
    border-radius: 22px;
    background: #f8fbff;
    border: 1px solid #e2e8f3;
}

.download-step strong {
    flex: 0 0 auto;
    width: 34px;
    height: 34px;
    border-radius: 12px;
    background: #eaf2ff;
    color: #1768E8;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.faq-card {
    padding: 24px;
}

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

.site-footer {
    background: #172033;
    color: #d8e1f2;
    padding-top: 40px;
}

.footer-inner {
    display: grid;
    gap: 24px;
    padding-bottom: 28px;
}

.footer-brand {
    display: flex;
    align-items: flex-start;
    gap: 14px;
}

.footer-brand strong,
.footer-brand p,
.footer-bottom p {
    color: #eef3ff;
}

.footer-brand p {
    margin-top: 8px;
    max-width: 520px;
    opacity: 0.78;
}

.footer-links {
    display: grid;
    gap: 10px;
}

.footer-links a {
    color: #d8e1f2;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 18px 0;
}

@media (min-width: 640px) {
    .highlight-grid,
    .privacy-cards,
    .policy-grid,
    .device-grid,
    .protocol-grid,
    .risk-grid,
    .faq-grid,
    .related-grid,
    .check-grid,
    .process-steps {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

    .section,
    .page-section {
        padding: 72px 0;
    }
}

@media (min-width: 860px) {
    .nav-toggle {
        display: none;
    }

    .main-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        padding: 0;
        border: 0;
        box-shadow: none;
        background: transparent;
        gap: 2px;
    }

    .main-nav a {
        padding: 8px 10px;
        font-size: 13px;
    }

    .hero-inner {
        grid-template-columns: 1.04fr 0.96fr;
        min-height: 620px;
    }

    .split-section,
    .feature-split {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .feature-panel {
        padding: 36px;
    }

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

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

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

    .article-layout {
        grid-template-columns: minmax(0, 1fr) 320px;
    }

    .article-card {
        padding: 38px;
    }

    .cta-panel {
        padding: 54px 70px;
    }

    .footer-inner {
        grid-template-columns: 1.2fr 0.8fr;
    }
}

@media (min-width: 1080px) {
    .main-nav a {
        padding: 10px 12px;
        font-size: 14px;
    }

    .vpn-saas-hero {
        padding-top: 58px;
    }
}

@media (max-width: 420px) {
    .header-inner,
    .footer-inner,
    .footer-bottom,
    .container,
    .hero-inner,
    .cta-panel {
        width: min(100% - 24px, 1120px);
    }

    .download-btn {
        width: 100%;
        padding: 0 18px;
    }

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

    .visual-tag {
        position: static;
        margin: 8px 6px 0 0;
        display: inline-flex;
    }

    .visual-tags {
        margin-top: 12px;
    }

    .product-frame {
        padding: 14px;
    }
}