* {
    box-sizing: border-box;
}

:root {
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1F2937;
    --muted: #667085;
    --light: #F5F7FB;
    --line: #E6EAF2;
    --soft-blue: #EEF5FF;
    --card: #FFFFFF;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --shadow: 0 18px 45px rgba(37, 56, 106, 0.10);
    --radius: 26px;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    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, 0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(230, 234, 242, 0.88);
}

.header-inner {
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #15213D;
    letter-spacing: 0.02em;
}

.logo img {
    width: 38px;
    height: 38px;
    border-radius: 12px;
    object-fit: cover;
    background: var(--soft-blue);
}

.nav-toggle {
    display: none;
}

.mobile-nav-button {
    width: 42px;
    height: 42px;
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    align-items: center;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: #fff;
}

.mobile-nav-button span {
    width: 18px;
    height: 2px;
    background: #253858;
    border-radius: 8px;
}

.main-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 74px;
    display: none;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: var(--shadow);
}

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

.main-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #46546A;
    font-size: 14px;
}

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

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 46px;
    padding: 0 24px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 750;
    box-shadow: 0 12px 24px rgba(41, 128, 254, 0.25);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    background: var(--blue-dark);
    transform: translateY(-2px);
    box-shadow: 0 16px 30px rgba(23, 104, 232, 0.28);
}

.gradient-bg {
    background: var(--gradient);
}

.vpn-lab-hero {
    position: relative;
    overflow: hidden;
    color: #fff;
    background: var(--gradient);
    border-radius: 0 0 34px 34px;
    padding: 58px 0 70px;
}

.vpn-lab-hero::after {
    content: "";
    position: absolute;
    inset: auto -80px -120px auto;
    width: 360px;
    height: 360px;
    border-radius: 999px;
    background: rgba(255,255,255,.16);
    filter: blur(3px);
}

.hero-grid {
    position: relative;
    z-index: 2;
    display: grid;
    gap: 34px;
    align-items: center;
}

.hero-copy h1 {
    margin: 0 0 18px;
    font-size: clamp(34px, 8vw, 62px);
    line-height: 1.08;
    letter-spacing: -0.04em;
}

.hero-copy p {
    margin: 0 0 24px;
    max-width: 620px;
    color: rgba(255,255,255,.88);
    font-size: 17px;
}

.hero-tags,
.lab-badges,
.inline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 22px;
}

.hero-tags span,
.lab-badges span,
.inline-tags span {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    padding: 7px 12px;
    color: #fff;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.22);
    font-size: 13px;
}

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

.lab-phone-card {
    position: relative;
    width: min(420px, 100%);
    margin: 0 auto;
    padding: 18px;
    border-radius: 34px;
    background: rgba(255,255,255,.20);
    border: 1px solid rgba(255,255,255,.24);
    box-shadow: 0 30px 80px rgba(20, 32, 87, .26);
}

.lab-phone-card img {
    width: 100%;
    max-height: 360px;
    object-fit: contain;
    border-radius: 24px;
}

.floating-status {
    position: absolute;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 13px;
    border-radius: 16px;
    color: #1E2B4D;
    background: rgba(255,255,255,.92);
    border: 1px solid rgba(255,255,255,.78);
    box-shadow: 0 16px 34px rgba(24, 39, 75, .18);
    font-size: 13px;
    font-weight: 700;
}

.floating-status::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 99px;
    background: #2BD576;
}

.status-one { top: 18px; left: 2px; }
.status-two { top: 98px; right: 0; }
.status-three { bottom: 78px; left: 4px; }
.status-four { bottom: 18px; right: 24px; }

section {
    padding: 58px 0;
}

.section-head {
    margin-bottom: 26px;
}

.section-kicker,
.category-badge {
    display: inline-flex;
    align-items: center;
    color: var(--blue);
    background: var(--soft-blue);
    border: 1px solid #D7E7FF;
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 13px;
    font-weight: 760;
}

.section-head h2,
.page-hero h1,
.content-copy h2,
.panel-title {
    color: #17213A;
    letter-spacing: -0.03em;
}

.section-head h2 {
    margin: 12px 0 10px;
    font-size: clamp(28px, 5vw, 42px);
    line-height: 1.2;
}

.section-head p {
    margin: 0;
    max-width: 740px;
    color: var(--muted);
}

.privacy-summary {
    margin-top: -34px;
    position: relative;
    z-index: 5;
    padding-top: 0;
}

.summary-grid,
.card-grid,
.category-grid,
.risk-grid,
.faq-grid,
.note-grid,
.service-card-grid {
    display: grid;
    gap: 16px;
}

.security-card,
.service-card,
.summary-card,
.risk-card,
.faq-item,
.note-card,
.step-card,
.feature-card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: 0 10px 26px rgba(39, 55, 94, .06);
}

.summary-card {
    min-height: 180px;
}

.summary-card .tag,
.service-card .tag,
.security-card .tag {
    display: inline-flex;
    border-radius: 999px;
    color: var(--blue);
    background: var(--soft-blue);
    padding: 5px 10px;
    font-size: 12px;
    font-weight: 760;
}

.summary-card h3,
.service-card h3,
.security-card h3,
.risk-card h3,
.note-card h3,
.step-card h3,
.feature-card h3,
.faq-item h3 {
    margin: 12px 0 8px;
    color: #17213A;
    line-height: 1.35;
}

.summary-card p,
.service-card p,
.security-card p,
.risk-card p,
.note-card p,
.step-card p,
.feature-card p,
.faq-item p {
    margin: 0;
    color: var(--muted);
}

.text-link {
    display: inline-flex;
    margin-top: 14px;
    color: var(--blue);
    font-weight: 740;
}

.lab-section,
.vpn-connection-section,
.privacy-protection-section,
.no-log-policy-section,
.global-nodes-section,
.high-speed-section,
.multi-device-section,
.encryption-protocol-section {
    background: #F7F9FC;
}

.section-panel {
    display: grid;
    gap: 24px;
    align-items: center;
    padding: 24px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 34px;
    box-shadow: var(--shadow);
}

.section-panel.soft {
    background: linear-gradient(180deg, #FFFFFF 0%, #F4F8FF 100%);
}

.section-panel.flat {
    box-shadow: none;
}

.content-copy p {
    color: var(--muted);
}

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

.content-copy li,
.clean-list li {
    position: relative;
    padding-left: 22px;
    color: #46546A;
}

.content-copy li::before,
.clean-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: .75em;
    width: 8px;
    height: 8px;
    border-radius: 99px;
    background: var(--blue);
}

.panel-image {
    background: var(--soft-blue);
    border-radius: 28px;
    padding: 18px;
    min-height: 230px;
    display: grid;
    place-items: center;
}

.panel-image img {
    max-height: 320px;
    object-fit: contain;
}

.safety-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 34px;
    padding: 26px;
    box-shadow: var(--shadow);
}

.safety-panel h2,
.safety-panel h3 {
    margin-top: 0;
}

.layer-grid {
    display: grid;
    gap: 14px;
}

.layer-item {
    padding: 18px;
    border: 1px solid var(--line);
    border-radius: 22px;
    background: #FBFCFF;
}

.layer-item strong {
    display: block;
    color: #17213A;
    margin-bottom: 6px;
}

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

.step-card {
    position: relative;
    padding-top: 52px;
}

.step-card::before {
    counter-increment: step;
    content: counter(step, decimal-leading-zero);
    position: absolute;
    top: 18px;
    left: 22px;
    color: var(--blue);
    font-weight: 850;
    letter-spacing: .06em;
}

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

.faq-item {
    box-shadow: none;
}

.cta-section {
    padding: 64px 0;
}

.cta-box {
    text-align: center;
    color: #fff;
    background: var(--gradient);
    border-radius: 34px;
    padding: 42px 22px;
    box-shadow: var(--shadow);
}

.cta-box h2 {
    margin: 0 0 12px;
    font-size: clamp(28px, 6vw, 42px);
    letter-spacing: -0.03em;
}

.cta-box p {
    max-width: 680px;
    margin: 0 auto 22px;
    color: rgba(255,255,255,.88);
}

.page-hero {
    background: linear-gradient(180deg, #EEF5FF 0%, #F7F9FC 100%);
    padding: 52px 0 28px;
}

.page-hero h1 {
    margin: 12px 0 12px;
    font-size: clamp(32px, 7vw, 52px);
    line-height: 1.15;
}

.page-hero p {
    max-width: 760px;
    margin: 0;
    color: var(--muted);
    font-size: 17px;
}

.page-layout {
    display: grid;
    gap: 24px;
    padding: 36px 0 64px;
}

.article-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 24px;
    box-shadow: var(--shadow);
}

.article-card h2 {
    margin-top: 0;
    color: #17213A;
}

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

.sidebar-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 26px;
    padding: 22px;
    align-self: start;
    box-shadow: 0 10px 26px rgba(39, 55, 94, .06);
}

.sidebar-card h3 {
    margin-top: 0;
}

.sidebar-card a {
    display: block;
    padding: 9px 0;
    color: var(--blue);
    font-weight: 700;
}

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

.install-steps {
    margin: 18px 0 0;
    padding-left: 20px;
    color: #46546A;
}

.site-footer {
    background: #17213A;
    color: rgba(255,255,255,.78);
    padding: 46px 0 24px;
}

.footer-grid {
    display: grid;
    gap: 24px;
}

.footer-brand {
    color: #fff;
    font-size: 22px;
    font-weight: 850;
    margin-bottom: 10px;
}

.site-footer h3 {
    margin: 0 0 10px;
    color: #fff;
    font-size: 16px;
}

.site-footer a {
    display: block;
    color: rgba(255,255,255,.76);
    margin: 7px 0;
}

.footer-bottom {
    margin-top: 28px;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,.12);
    display: flex;
    flex-direction: column;
    gap: 8px;
    font-size: 13px;
}

@media (min-width: 720px) {
    .summary-grid,
    .card-grid,
    .note-grid,
    .service-card-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    .risk-grid,
    .category-grid,
    .faq-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    .process-steps {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 960px) {
    .mobile-nav-button {
        display: none;
    }
    .main-nav {
        position: static;
        display: flex;
        align-items: center;
        gap: 4px;
        padding: 0;
        border: 0;
        box-shadow: none;
        background: transparent;
    }
    .main-nav a {
        padding: 8px 10px;
        font-size: 14px;
    }
    .hero-grid {
        grid-template-columns: 1.06fr .94fr;
    }
    .vpn-lab-hero {
        padding: 78px 0 92px;
    }
    .summary-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
    .section-panel {
        grid-template-columns: 1fr 1fr;
        padding: 36px;
    }
    .section-panel.reverse .panel-image {
        order: -1;
    }
    .privacy-protection-section .section-panel,
    .encryption-protocol-section .section-panel {
        grid-template-columns: .86fr 1.14fr;
    }
    .layer-grid {
        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) 300px;
        align-items: start;
    }
    .footer-grid {
        grid-template-columns: 1.4fr .8fr .8fr .8fr;
    }
    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
    }
}

@media (min-width: 1180px) {
    .main-nav a {
        padding: 8px 12px;
    }
}