* {
    box-sizing: border-box;
}

:root {
    --brand-gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #64748b;
    --light: #f6f8fc;
    --line: #e5eaf3;
    --panel: #ffffff;
    --shadow: 0 18px 50px rgba(28, 42, 86, 0.10);
    --radius-xl: 32px;
    --radius-lg: 24px;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #ffffff;
    line-height: 1.72;
    overflow-x: hidden;
}

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

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

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(229, 234, 243, 0.9);
}

.header-inner {
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

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

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

.site-nav {
    display: none;
    position: absolute;
    left: 18px;
    right: 18px;
    top: 70px;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    border-radius: 22px;
}

.site-nav a {
    display: block;
    padding: 12px 14px;
    color: #334155;
    border-radius: 14px;
    font-size: 15px;
}

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

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

.nav-toggle-label {
    width: 42px;
    height: 42px;
    border: 1px solid var(--line);
    border-radius: 14px;
    display: grid;
    place-items: center;
    gap: 4px;
    padding: 10px;
}

.nav-toggle-label span {
    width: 20px;
    height: 2px;
    display: block;
    background: #1f2937;
    border-radius: 99px;
}

.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;
    background: var(--blue);
    color: #fff;
    font-weight: 700;
    box-shadow: 0 14px 28px rgba(41, 128, 254, 0.26);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    background: var(--blue-dark);
    transform: translateY(-2px);
    box-shadow: 0 18px 34px rgba(23, 104, 232, 0.28);
}

.section-eyebrow,
.badge {
    display: inline-flex;
    align-items: center;
    padding: 6px 12px;
    border-radius: 999px;
    color: var(--blue);
    background: #edf5ff;
    font-size: 13px;
    font-weight: 700;
    margin-bottom: 10px;
}

.vpn-saas-hero {
    position: relative;
    isolation: isolate;
    overflow: hidden;
    padding: 52px 0 74px;
    background: #f8fbff;
}

.vpn-saas-hero::before {
    content: "";
    position: absolute;
    inset: 0 0 auto 0;
    height: 78%;
    background: var(--brand-gradient);
    clip-path: polygon(0 0, 100% 0, 100% 84%, 0 100%);
    z-index: -2;
}

.vpn-saas-hero::after {
    content: "";
    position: absolute;
    width: 420px;
    height: 420px;
    right: -130px;
    top: 10px;
    background: rgba(255, 255, 255, 0.20);
    border-radius: 999px;
    filter: blur(2px);
    z-index: -1;
}

.hero-grid {
    display: grid;
    gap: 36px;
    align-items: center;
}

.hero-copy {
    color: #fff;
}

.hero-copy h1 {
    margin: 0 0 18px;
    font-size: clamp(34px, 8vw, 64px);
    line-height: 1.08;
    letter-spacing: -0.04em;
}

.hero-copy p {
    margin: 0 0 24px;
    max-width: 650px;
    color: rgba(255,255,255,.88);
    font-size: 17px;
}

.hero-tags,
.float-tags,
.inline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 18px;
}

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

.hero-visual {
    position: relative;
    padding: 20px;
}

.product-card {
    position: relative;
    overflow: hidden;
    border-radius: 34px;
    background: rgba(255,255,255,.92);
    box-shadow: 0 28px 70px rgba(16, 24, 55, .20);
    border: 1px solid rgba(255,255,255,.55);
    padding: 18px;
}

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

.status-card {
    position: absolute;
    display: none;
    padding: 11px 14px;
    border-radius: 18px;
    background: rgba(255,255,255,.93);
    box-shadow: 0 16px 44px rgba(15, 23, 42, 0.16);
    color: #1e293b;
    font-weight: 700;
    font-size: 13px;
}

.status-card.one { top: 14px; left: 4px; }
.status-card.two { right: 0; top: 33%; }
.status-card.three { left: 8px; bottom: 20%; }
.status-card.four { right: 24px; bottom: 6px; }

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

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

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

.section-header h2,
.page-hero h1 {
    margin: 0 0 12px;
    font-size: clamp(26px, 4vw, 42px);
    line-height: 1.22;
    letter-spacing: -0.03em;
}

.section-header p,
.page-hero p,
.card p,
.feature-copy p,
.faq-item p,
.step-card p,
.risk-card p,
.tip-box p,
.sub-card p,
.download-steps p {
    color: var(--muted);
    margin: 0;
}

.product-highlights {
    margin-top: -34px;
    position: relative;
    z-index: 3;
}

.highlight-grid,
.card-grid,
.risk-grid,
.faq-grid,
.related-grid {
    display: grid;
    gap: 18px;
}

.highlight-card,
.card,
.risk-card,
.faq-item,
.step-card,
.sub-card,
.tip-box,
.side-panel,
.download-steps li {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    box-shadow: 0 12px 34px rgba(29, 41, 73, 0.06);
}

.highlight-card {
    padding: 24px;
}

.highlight-card .tag {
    display: inline-flex;
    padding: 4px 10px;
    color: var(--blue);
    background: #edf5ff;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 700;
}

.highlight-card h3,
.card h3,
.risk-card h3,
.faq-item h3,
.step-card h3,
.sub-card h3,
.tip-box h3,
.side-panel h3 {
    margin: 12px 0 8px;
    line-height: 1.35;
}

.text-link {
    display: inline-flex;
    color: var(--blue);
    font-weight: 700;
    margin-top: 14px;
}

.feature-section {
    background: #fff;
}

.soft-bg {
    background: #f7f9fe;
}

.feature-panel,
.privacy-panel,
.tech-panel,
.device-panel,
.node-panel,
.speed-panel {
    display: grid;
    gap: 28px;
    align-items: center;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-xl);
    padding: 24px;
    box-shadow: var(--shadow);
}

.feature-copy h2 {
    margin: 8px 0 12px;
    font-size: clamp(25px, 4vw, 40px);
    line-height: 1.22;
    letter-spacing: -0.03em;
}

.feature-copy ul,
.check-list,
.page-list {
    padding: 0;
    margin: 18px 0 0;
    list-style: none;
    display: grid;
    gap: 10px;
}

.feature-copy li,
.check-list li,
.page-list li {
    position: relative;
    padding-left: 24px;
    color: #475569;
}

.feature-copy li::before,
.check-list li::before,
.page-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 12px;
    width: 8px;
    height: 8px;
    background: var(--blue);
    border-radius: 999px;
}

.visual-frame {
    overflow: hidden;
    border-radius: 28px;
    background: #eef5ff;
    padding: 14px;
}

.visual-frame img {
    border-radius: 22px;
    width: 100%;
}

.privacy-protection-section .privacy-panel {
    background: linear-gradient(180deg, #fff 0%, #f7faff 100%);
}

.privacy-cards,
.policy-cards,
.protocol-cards,
.device-cards {
    display: grid;
    gap: 16px;
    margin-top: 22px;
}

.card,
.sub-card,
.tip-box,
.side-panel {
    padding: 22px;
}

.policy-strip {
    border-radius: var(--radius-xl);
    padding: 28px;
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

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

.step-card {
    position: relative;
    padding: 24px;
    overflow: hidden;
}

.step-number {
    display: inline-grid;
    place-items: center;
    width: 38px;
    height: 38px;
    border-radius: 14px;
    background: var(--brand-gradient);
    color: #fff;
    font-weight: 800;
}

.risk-card {
    padding: 22px;
    border-left: 4px solid var(--blue);
}

.risk-card strong {
    display: block;
    margin: 10px 0 6px;
}

.faq-item {
    padding: 22px;
}

.cta-section {
    padding: 70px 0;
}

.cta-panel {
    position: relative;
    overflow: hidden;
    border-radius: 36px;
    padding: 42px 24px;
    text-align: center;
    background: var(--brand-gradient);
    color: #fff;
    box-shadow: 0 26px 70px rgba(74, 74, 210, .24);
}

.cta-panel p {
    margin: 0 auto 22px;
    max-width: 720px;
    color: rgba(255,255,255,.86);
}

.cta-panel h2 {
    margin: 0 0 12px;
    font-size: clamp(26px, 4vw, 42px);
}

.page-hero {
    padding: 54px 0 34px;
    background: linear-gradient(180deg, #f7faff 0%, #fff 100%);
}

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

.content-layout {
    display: grid;
    gap: 24px;
    padding: 42px 0 72px;
}

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

.article-panel h2 {
    margin-top: 0;
    font-size: clamp(22px, 3vw, 32px);
}

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

.article-panel p {
    color: #475569;
}

.article-cta {
    margin-top: 26px;
}

.side-panel {
    align-self: start;
    background: #f8fbff;
}

.side-panel a {
    display: block;
    padding: 11px 0;
    border-bottom: 1px solid var(--line);
    color: #475569;
}

.side-panel a:hover {
    color: var(--blue);
}

.download-page .download-box {
    text-align: center;
    max-width: 760px;
    margin: 0 auto;
}

.download-steps {
    margin: 30px 0 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 14px;
    counter-reset: installstep;
}

.download-steps li {
    padding: 20px;
    text-align: left;
}

.download-steps span {
    display: inline-grid;
    place-items: center;
    width: 32px;
    height: 32px;
    margin-right: 8px;
    border-radius: 12px;
    background: #edf5ff;
    color: var(--blue);
    font-weight: 800;
}

.site-footer {
    background: #111827;
    color: #d1d5db;
    padding: 52px 0 24px;
}

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

.footer-logo {
    color: #fff;
    margin-bottom: 12px;
}

.site-footer p {
    color: #9ca3af;
    margin: 0;
}

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

.site-footer a:not(.footer-logo) {
    display: block;
    color: #9ca3af;
    margin: 8px 0;
}

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

.footer-bottom {
    margin-top: 34px;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,.10);
    color: #9ca3af;
    font-size: 14px;
}

@media (min-width: 700px) {
    .highlight-grid,
    .card-grid,
    .privacy-cards,
    .policy-cards,
    .protocol-cards,
    .device-cards,
    .related-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

    .footer-grid {
        grid-template-columns: 1.5fr repeat(3, 1fr);
    }
}

@media (min-width: 960px) {
    .nav-toggle-label { display: none; }
    .site-nav {
        position: static;
        display: flex;
        align-items: center;
        gap: 4px;
        padding: 0;
        background: transparent;
        border: none;
        box-shadow: none;
        border-radius: 0;
    }

    .site-nav a {
        display: inline-flex;
        padding: 9px 11px;
        font-size: 14px;
    }

    .hero-grid {
        grid-template-columns: 1.02fr .98fr;
    }

    .status-card { display: block; }

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

    .feature-panel,
    .privacy-panel,
    .tech-panel,
    .device-panel,
    .node-panel,
    .speed-panel {
        grid-template-columns: 1fr 1fr;
        padding: 36px;
    }

    .feature-panel.reverse .visual-frame,
    .speed-panel.reverse .visual-frame,
    .device-panel.reverse .visual-frame {
        order: -1;
    }

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

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

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

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

    .article-panel {
        padding: 36px;
    }
}

@media (max-width: 520px) {
    .container { width: min(100% - 28px, 1120px); }
    .vpn-saas-hero { padding-top: 36px; }
    .page-section { padding: 54px 0; }
    .download-btn { width: 100%; }
    .hero-tags span,
    .float-tags span,
    .inline-tags span { font-size: 12px; }
    .feature-panel,
    .privacy-panel,
    .tech-panel,
    .device-panel,
    .node-panel,
    .speed-panel,
    .article-panel { border-radius: 24px; }
}