:root {
    --brand-gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #182033;
    --muted: #647086;
    --light: #F5F7FB;
    --line: #E5EAF3;
    --soft-blue: #F0F6FF;
    --white: #FFFFFF;
    --radius-lg: 32px;
    --radius-md: 24px;
    --shadow: 0 20px 55px rgba(31, 45, 92, .10);
    --shadow-soft: 0 10px 30px rgba(31, 45, 92, .08);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", 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;
}

p {
    margin: 0 0 16px;
}

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

.container {
    width: min(100% - 32px, 1180px);
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, .94);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(229, 234, 243, .85);
}

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

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #1A2542;
    letter-spacing: .02em;
    white-space: nowrap;
}

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

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

.nav-toggle {
    width: 44px;
    height: 44px;
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: var(--white);
    cursor: pointer;
}

.nav-toggle span {
    width: 19px;
    height: 2px;
    background: #26324D;
    border-radius: 999px;
}

.main-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 74px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
}

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

.main-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #39465F;
    font-size: 14px;
    font-weight: 650;
}

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

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: var(--blue);
    color: #FFFFFF;
    font-weight: 800;
    box-shadow: 0 14px 30px rgba(41, 128, 254, .25);
    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 38px rgba(23, 104, 232, .28);
}

.section {
    padding: 64px 0;
}

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

.section-head {
    display: grid;
    gap: 14px;
    margin-bottom: 28px;
}

.section-head.center {
    text-align: center;
    max-width: 780px;
    margin-left: auto;
    margin-right: auto;
}

.section-eyebrow,
.badge {
    display: inline-flex;
    width: fit-content;
    align-items: center;
    padding: 6px 12px;
    border-radius: 999px;
    color: var(--blue);
    background: var(--soft-blue);
    font-size: 13px;
    font-weight: 800;
}

.section-title,
.page-hero h1 {
    font-size: clamp(28px, 5vw, 48px);
    letter-spacing: -.04em;
}

.section-desc,
.page-summary {
    color: var(--muted);
    font-size: 16px;
    max-width: 760px;
}

.gradient-bg {
    background: var(--brand-gradient);
    color: #FFFFFF;
}

.vpn-saas-hero {
    position: relative;
    padding: 34px 0 52px;
    overflow: hidden;
    background: linear-gradient(180deg, #F7FAFF 0%, #FFFFFF 100%);
}

.hero-panel {
    position: relative;
    overflow: hidden;
    border-radius: 0 0 36px 36px;
    background: var(--brand-gradient);
    color: #FFFFFF;
    padding: 48px 22px;
    box-shadow: var(--shadow);
}

.hero-panel::after {
    content: "";
    position: absolute;
    right: -80px;
    top: -120px;
    width: 320px;
    height: 320px;
    background: rgba(255, 255, 255, .16);
    border-radius: 44% 56% 60% 40%;
    transform: rotate(-18deg);
}

.hero-panel::before {
    content: "";
    position: absolute;
    left: -40px;
    bottom: -80px;
    width: 280px;
    height: 220px;
    background: rgba(255, 255, 255, .12);
    clip-path: polygon(0 32%, 100% 0, 84% 100%, 0 100%);
}

.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 34px;
    align-items: center;
}

.hero-copy h1 {
    color: #FFFFFF;
    font-size: clamp(34px, 8vw, 64px);
    letter-spacing: -.05em;
    max-width: 720px;
}

.hero-copy p {
    color: rgba(255, 255, 255, .86);
    font-size: 17px;
    max-width: 620px;
    margin-top: 18px;
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 22px 0 26px;
}

.hero-tags span,
.floating-label,
.protocol-chip {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 800;
}

.hero-tags span {
    padding: 8px 12px;
    background: rgba(255, 255, 255, .15);
    border: 1px solid rgba(255, 255, 255, .22);
    color: #FFFFFF;
}

.hero-visual {
    position: relative;
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-device {
    width: min(420px, 82vw);
    padding: 18px;
    border-radius: 34px;
    background: rgba(255, 255, 255, .18);
    border: 1px solid rgba(255, 255, 255, .28);
    backdrop-filter: blur(12px);
}

.hero-device img {
    border-radius: 26px;
    box-shadow: 0 26px 60px rgba(15, 25, 68, .25);
}

.floating-label {
    position: absolute;
    padding: 9px 13px;
    background: #FFFFFF;
    color: #1A2542;
    box-shadow: var(--shadow-soft);
}

.label-one { left: 2%; top: 10%; }
.label-two { right: 1%; top: 22%; }
.label-three { left: 7%; bottom: 12%; }
.label-four { right: 4%; bottom: 2%; }

.product-highlights {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

.highlight-card,
.info-card,
.risk-card,
.faq-item,
.step-card,
.tip-card,
.related-card {
    background: #FFFFFF;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-soft);
}

.highlight-card {
    padding: 22px;
}

.highlight-tag {
    display: inline-flex;
    margin-bottom: 14px;
    padding: 5px 10px;
    color: var(--blue);
    background: var(--soft-blue);
    border-radius: 999px;
    font-size: 12px;
    font-weight: 900;
}

.highlight-card h3,
.info-card h3,
.risk-card h3,
.step-card h3,
.tip-card h3,
.related-card h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

.highlight-card p,
.info-card p,
.risk-card p,
.step-card p,
.tip-card p,
.related-card p {
    color: var(--muted);
    font-size: 15px;
}

.text-link {
    color: var(--blue);
    font-weight: 800;
}

.feature-panel {
    display: grid;
    gap: 26px;
    align-items: center;
    padding: 24px;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: #FFFFFF;
    box-shadow: var(--shadow-soft);
}

.feature-panel.reverse .feature-media {
    order: -1;
}

.feature-copy ul,
.check-list {
    margin: 16px 0 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 10px;
}

.feature-copy li,
.check-list li {
    position: relative;
    padding-left: 24px;
    color: #3B465E;
}

.feature-copy li::before,
.check-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: .76em;
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: var(--blue);
}

.feature-media {
    border-radius: 30px;
    padding: 16px;
    background: linear-gradient(180deg, #F7FAFF, #EEF4FF);
}

.feature-media img {
    border-radius: 24px;
    box-shadow: 0 14px 40px rgba(31, 45, 92, .12);
}

.speed-card {
    background: linear-gradient(180deg, #FFFFFF, #F5F8FF);
}

.node-grid,
.privacy-grid,
.no-log-grid,
.device-grid,
.protocol-grid,
.risk-grid,
.faq-grid,
.related-grid,
.content-card-grid {
    display: grid;
    gap: 16px;
}

.info-card,
.risk-card,
.step-card,
.tip-card,
.related-card {
    padding: 22px;
}

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

.privacy-protection-section .privacy-wrap {
    display: grid;
    gap: 18px;
    padding: 24px;
    border-radius: var(--radius-lg);
    background: #FFFFFF;
    border: 1px solid var(--line);
    box-shadow: var(--shadow-soft);
}

.privacy-image {
    border-radius: 28px;
    background: var(--soft-blue);
    padding: 16px;
}

.privacy-image img {
    border-radius: 22px;
}

.no-log-policy-section .no-log-wrap,
.encryption-protocol-section .protocol-wrap,
.safety-panel {
    padding: 24px;
    border-radius: var(--radius-lg);
    background: #FFFFFF;
    border: 1px solid var(--line);
    box-shadow: var(--shadow-soft);
}

.protocol-chip {
    padding: 8px 12px;
    color: #395079;
    background: #F0F6FF;
    border: 1px solid #DCE8FB;
}

.chip-row {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 18px;
}

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

.step-card {
    position: relative;
    padding-top: 58px;
}

.step-card::before {
    counter-increment: step-counter;
    content: counter(step-counter, decimal-leading-zero);
    position: absolute;
    left: 22px;
    top: 18px;
    color: var(--blue);
    font-size: 20px;
    font-weight: 900;
}

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

.risk-card p strong {
    color: #233150;
}

.faq-item {
    padding: 20px;
}

.faq-item h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.faq-item p {
    color: var(--muted);
    margin-bottom: 0;
}

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

.cta-panel {
    text-align: center;
    border-radius: var(--radius-lg);
    padding: 42px 22px;
    color: #FFFFFF;
    background: var(--brand-gradient);
    box-shadow: var(--shadow);
    overflow: hidden;
    position: relative;
}

.cta-panel h2 {
    color: #FFFFFF;
    font-size: clamp(28px, 5vw, 44px);
}

.cta-panel p {
    color: rgba(255,255,255,.86);
    max-width: 650px;
    margin: 16px auto 24px;
}

.page-hero {
    padding: 58px 0 34px;
    background: linear-gradient(180deg, #F7FAFF 0%, #FFFFFF 100%);
}

.page-hero-inner {
    display: grid;
    gap: 16px;
    padding: 26px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--line);
    background: #FFFFFF;
    box-shadow: var(--shadow-soft);
}

.page-layout {
    display: grid;
    gap: 22px;
    align-items: start;
}

.article-card {
    padding: 24px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--line);
    background: #FFFFFF;
    box-shadow: var(--shadow-soft);
}

.article-card h2 {
    font-size: 26px;
    margin: 24px 0 12px;
}

.article-card h2:first-child {
    margin-top: 0;
}

.article-card p {
    color: #4D5A72;
}

.sidebar {
    display: grid;
    gap: 16px;
}

.side-panel {
    padding: 20px;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: #FFFFFF;
    box-shadow: var(--shadow-soft);
}

.side-panel h3 {
    margin-bottom: 12px;
    font-size: 18px;
}

.side-panel a,
.side-panel li {
    color: #56647A;
    font-size: 15px;
}

.side-panel ul {
    margin: 0;
    padding-left: 18px;
}

.simple-steps {
    display: grid;
    gap: 12px;
    margin: 20px 0;
    padding: 0;
    list-style: none;
    counter-reset: simple-step;
}

.simple-steps li {
    counter-increment: simple-step;
    padding: 16px 16px 16px 54px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #F9FBFF;
    position: relative;
}

.simple-steps li::before {
    content: counter(simple-step);
    position: absolute;
    left: 16px;
    top: 15px;
    width: 26px;
    height: 26px;
    display: grid;
    place-items: center;
    color: #FFFFFF;
    font-weight: 900;
    border-radius: 50%;
    background: var(--blue);
}

.download-area {
    margin-top: 26px;
    padding: 24px;
    text-align: center;
    border-radius: var(--radius-md);
    background: linear-gradient(180deg, #F2F7FF, #FFFFFF);
    border: 1px solid var(--line);
}

.download-page-panel {
    display: grid;
    gap: 22px;
    padding: 26px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--line);
    background: #FFFFFF;
    box-shadow: var(--shadow-soft);
}

.site-footer {
    margin-top: 50px;
    background: #111A2F;
    color: rgba(255, 255, 255, .72);
    padding: 52px 0 22px;
}

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

.footer-brand p {
    max-width: 380px;
}

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

.site-footer h3 {
    color: #FFFFFF;
    margin-bottom: 12px;
    font-size: 17px;
}

.site-footer a {
    display: block;
    color: rgba(255, 255, 255, .72);
    margin: 8px 0;
    font-size: 14px;
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, .12);
    margin-top: 34px;
    padding-top: 18px;
    font-size: 14px;
}

@media (min-width: 640px) {
    .product-highlights,
    .privacy-grid,
    .no-log-grid,
    .device-grid,
    .protocol-grid,
    .risk-grid,
    .faq-grid,
    .content-card-grid,
    .related-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

@media (min-width: 920px) {
    .container {
        width: min(100% - 48px, 1180px);
    }

    .nav-toggle {
        display: none;
    }

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

    .main-nav a {
        font-size: 14px;
        padding: 9px 10px;
    }

    .hero-panel {
        padding: 70px 56px;
        border-radius: 0 0 54px 54px;
        clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
    }

    .hero-grid {
        grid-template-columns: 1.05fr .95fr;
    }

    .hero-visual {
        min-height: 470px;
    }

    .product-highlights {
        grid-template-columns: repeat(4, minmax(0, 1fr));
        margin-top: -36px;
        position: relative;
        z-index: 2;
    }

    .feature-panel {
        grid-template-columns: 1fr 1fr;
        padding: 34px;
    }

    .feature-panel.reverse .feature-media {
        order: 2;
    }

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

    .privacy-protection-section .privacy-wrap {
        grid-template-columns: 1.2fr .8fr;
        padding: 34px;
    }

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

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

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

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

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

    .page-layout {
        grid-template-columns: minmax(0, 1fr) 310px;
    }

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

@media (min-width: 1100px) {
    .main-nav a {
        padding: 9px 13px;
    }
}

@media (max-width: 420px) {
    .container {
        width: min(100% - 24px, 1180px);
    }

    .hero-panel,
    .feature-panel,
    .article-card,
    .download-page-panel {
        padding-left: 18px;
        padding-right: 18px;
    }

    .floating-label {
        font-size: 12px;
        padding: 7px 10px;
    }

    .download-btn {
        width: 100%;
    }
}