* {
    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: #243044;
    background: #f6f8fc;
    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;
    color: #5b667a;
}

h1, h2, h3 {
    margin: 0;
    color: #152033;
    line-height: 1.25;
}

ul, ol {
    margin: 0;
    padding-left: 20px;
    color: #5b667a;
}

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(214, 221, 232, 0.78);
}

.nav-shell {
    width: min(1180px, calc(100% - 24px));
    margin: 0 auto;
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 800;
    color: #17223b;
    white-space: nowrap;
}

.brand-logo {
    width: 42px;
    height: 42px;
    border-radius: 14px;
    object-fit: cover;
    box-shadow: 0 12px 24px rgba(41, 128, 254, 0.18);
}

.main-nav {
    display: none;
    position: absolute;
    top: 70px;
    left: 12px;
    right: 12px;
    padding: 12px;
    background: #ffffff;
    border: 1px solid #e5eaf2;
    border-radius: 22px;
    box-shadow: 0 24px 70px rgba(22, 40, 80, 0.14);
}

.main-nav.is-open {
    display: grid;
    gap: 6px;
}

.main-nav a {
    padding: 12px 14px;
    border-radius: 14px;
    font-size: 14px;
    color: #4f5f78;
    font-weight: 650;
}

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

.nav-toggle {
    width: 44px;
    height: 44px;
    border: 1px solid #e4ebf5;
    background: #ffffff;
    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: #25344c;
    border-radius: 99px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #ffffff;
    font-weight: 800;
    letter-spacing: 0.02em;
    box-shadow: 0 16px 32px rgba(41, 128, 254, 0.28);
    transition: background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 18px 38px rgba(23, 104, 232, 0.3);
}

.text-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: #2980FE;
    font-weight: 750;
    margin-top: 6px;
}

.text-link::after {
    content: "→";
}

.section {
    padding: 58px 0;
}

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

.section-kicker,
.badge {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 6px 12px;
    border-radius: 999px;
    background: #eef5ff;
    color: #2980FE;
    font-size: 13px;
    font-weight: 800;
    margin-bottom: 14px;
}

.section-heading h2,
.feature-copy h2 {
    font-size: clamp(26px, 5vw, 42px);
    margin-bottom: 12px;
}

.section-heading p,
.feature-copy p {
    max-width: 760px;
}

.vpn-saas-hero {
    position: relative;
    overflow: hidden;
    padding: 46px 0 56px;
    background: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
}

.vpn-saas-hero::after {
    content: "";
    position: absolute;
    left: -8%;
    right: -8%;
    bottom: -86px;
    height: 170px;
    background: #f6f8fc;
    transform: rotate(-3deg);
    transform-origin: left center;
}

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

.hero-copy h1 {
    color: #ffffff;
    font-size: clamp(34px, 9vw, 62px);
    max-width: 760px;
    letter-spacing: -0.04em;
    margin-bottom: 18px;
}

.hero-copy p {
    color: rgba(255, 255, 255, 0.86);
    font-size: 16px;
    max-width: 670px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 14px;
    margin: 24px 0 20px;
}

.hero-note {
    color: rgba(255, 255, 255, 0.84);
    font-size: 13px;
}

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

.hero-tags span,
.floating-card {
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.16);
    color: #ffffff;
    border: 1px solid rgba(255, 255, 255, 0.26);
    font-size: 13px;
    font-weight: 750;
}

.hero-visual {
    position: relative;
    padding: 18px;
    border-radius: 36px;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.25);
    box-shadow: 0 30px 80px rgba(24, 30, 80, 0.24);
}

.hero-visual img {
    width: 100%;
    border-radius: 30px;
    background: #ffffff;
}

.floating-card {
    position: static;
    display: inline-flex;
    margin: 8px 6px 0 0;
    background: #ffffff;
    color: #25344c;
    border-color: rgba(255, 255, 255, 0.42);
    box-shadow: 0 14px 28px rgba(23, 42, 98, 0.14);
}

.product-highlights {
    position: relative;
    z-index: 3;
    margin-top: -24px;
}

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

.highlight-card,
.info-card,
.risk-card,
.faq-item,
.step-card,
.article-card,
.download-panel,
.safety-panel,
.sidebar-card {
    background: #ffffff;
    border: 1px solid #e5eaf2;
    border-radius: 28px;
    box-shadow: 0 18px 55px rgba(31, 45, 78, 0.08);
}

.highlight-card {
    padding: 22px;
}

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

.highlight-card h3 {
    font-size: 19px;
    margin-bottom: 8px;
}

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

.feature-panel {
    display: grid;
    gap: 28px;
    align-items: center;
    padding: 24px;
    border-radius: 34px;
    background: #ffffff;
    border: 1px solid #e5eaf2;
    box-shadow: 0 24px 80px rgba(31, 45, 78, 0.08);
}

.feature-panel.soft {
    background: linear-gradient(180deg, #ffffff 0%, #f5f8ff 100%);
}

.feature-panel.gradient-soft {
    background: linear-gradient(135deg, rgba(53, 88, 242, 0.09), rgba(184, 77, 218, 0.09));
}

.feature-copy ul {
    display: grid;
    gap: 10px;
    margin: 18px 0;
}

.feature-copy li::marker {
    color: #2980FE;
}

.feature-image {
    position: relative;
}

.feature-image img {
    border-radius: 28px;
    border: 1px solid #e7edf6;
    box-shadow: 0 24px 58px rgba(21, 32, 51, 0.12);
}

.metric-row {
    display: grid;
    gap: 12px;
    margin-top: 18px;
}

.metric-card {
    padding: 16px;
    border-radius: 20px;
    background: #f7f9fd;
    border: 1px solid #e8edf5;
}

.metric-card strong {
    display: block;
    color: #152033;
    margin-bottom: 4px;
}

.privacy-protection-section {
    background: #eef3fb;
}

.privacy-layout {
    display: grid;
    gap: 18px;
}

.privacy-card {
    padding: 22px;
    background: #ffffff;
    border-radius: 28px;
    border: 1px solid #e5eaf2;
}

.privacy-card h3 {
    margin-bottom: 8px;
}

.privacy-visual {
    padding: 16px;
    border-radius: 32px;
    background: linear-gradient(135deg, #eef5ff, #ffffff);
    border: 1px solid #e5eaf2;
}

.privacy-visual img {
    border-radius: 24px;
}

.no-log-policy-section .info-grid,
.encryption-protocol-section .info-grid,
.related-grid {
    display: grid;
    gap: 16px;
}

.info-card {
    padding: 22px;
}

.info-card h3 {
    margin-bottom: 8px;
}

.multi-device-section {
    background: linear-gradient(180deg, #f6f8fc 0%, #ffffff 100%);
}

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

.device-card {
    padding: 18px;
    border-radius: 24px;
    background: #ffffff;
    border: 1px solid #e5eaf2;
}

.device-card strong {
    color: #152033;
}

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

.step-card {
    position: relative;
    padding: 22px;
    overflow: hidden;
}

.step-card::before {
    counter-increment: step;
    content: counter(step, decimal-leading-zero);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    margin-bottom: 14px;
    border-radius: 16px;
    background: #2980FE;
    color: #ffffff;
    font-weight: 900;
}

.step-card h3 {
    margin-bottom: 8px;
}

.safety-panel {
    padding: 24px;
    border-left: 6px solid #2980FE;
}

.risk-grid {
    display: grid;
    gap: 16px;
    margin-top: 22px;
}

.risk-card {
    padding: 20px;
}

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

.risk-card .advice {
    padding: 12px;
    border-radius: 16px;
    background: #f0f6ff;
    color: #345273;
    font-size: 14px;
}

.faq-list {
    display: grid;
    gap: 14px;
}

.faq-item {
    padding: 20px;
}

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

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

.cta-panel {
    overflow: hidden;
    position: relative;
    padding: 34px 24px;
    border-radius: 36px;
    background: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    text-align: center;
    color: #ffffff;
}

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

.cta-panel p {
    max-width: 680px;
    margin: 12px auto 22px;
    color: rgba(255, 255, 255, 0.86);
}

.page-hero {
    padding: 54px 0 38px;
    background: linear-gradient(135deg, #ffffff 0%, #eef5ff 100%);
    border-bottom: 1px solid #e3eaf4;
}

.page-hero .container {
    max-width: 980px;
}

.page-hero h1 {
    font-size: clamp(30px, 7vw, 52px);
    margin-bottom: 14px;
}

.page-layout {
    display: grid;
    gap: 24px;
    align-items: start;
    padding: 44px 0 64px;
}

.article-main {
    display: grid;
    gap: 18px;
}

.article-card {
    padding: 24px;
}

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

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

.check-list li {
    padding: 14px 14px 14px 42px;
    border-radius: 18px;
    background: #f7f9fd;
    border: 1px solid #e8edf5;
    position: relative;
}

.check-list li::before {
    content: "✓";
    position: absolute;
    left: 14px;
    top: 14px;
    color: #2980FE;
    font-weight: 900;
}

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

.sidebar-card {
    padding: 20px;
}

.sidebar-card h3 {
    font-size: 18px;
    margin-bottom: 10px;
}

.sidebar-card a {
    display: block;
    padding: 9px 0;
    color: #2980FE;
    font-weight: 700;
    border-bottom: 1px solid #eef2f7;
}

.sidebar-card a:last-child {
    border-bottom: none;
}

.download-panel {
    padding: 28px;
    text-align: center;
}

.install-steps {
    display: grid;
    gap: 14px;
    padding: 0;
    list-style: none;
}

.install-steps li {
    display: grid;
    grid-template-columns: 44px 1fr;
    gap: 14px;
    padding: 16px;
    border-radius: 22px;
    background: #ffffff;
    border: 1px solid #e5eaf2;
}

.install-steps span {
    width: 44px;
    height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
    background: #2980FE;
    color: #ffffff;
    font-weight: 900;
}

.about-grid {
    display: grid;
    gap: 18px;
}

.site-footer {
    background: #101827;
    color: #c7d1e0;
    padding-top: 48px;
}

.site-footer p,
.site-footer a {
    color: #c7d1e0;
}

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

.footer-logo span {
    color: #ffffff;
}

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

.site-footer a {
    display: block;
    padding: 5px 0;
    font-size: 14px;
}

.footer-bottom {
    margin-top: 32px;
    padding: 18px 16px;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    margin: 0;
    font-size: 13px;
}

@media (min-width: 680px) {
    .highlight-grid,
    .risk-grid,
    .related-grid,
    .info-grid,
    .device-grid,
    .about-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

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

@media (min-width: 960px) {
    .site-header {
        position: sticky;
    }

    .nav-toggle {
        display: none;
    }

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

    .main-nav a {
        padding: 9px 11px;
        font-size: 14px;
    }

    .vpn-saas-hero {
        padding: 78px 0 112px;
    }

    .hero-grid {
        grid-template-columns: minmax(0, 1.05fr) minmax(360px, 0.95fr);
    }

    .floating-card {
        position: absolute;
        margin: 0;
    }

    .floating-card.one { top: 32px; left: -22px; }
    .floating-card.two { right: -18px; top: 92px; }
    .floating-card.three { left: 28px; bottom: 32px; }
    .floating-card.four { right: 28px; bottom: -16px; }

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

    .feature-panel {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        padding: 34px;
    }

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

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

    .privacy-layout {
        grid-template-columns: 1.1fr 0.9fr;
        align-items: center;
    }

    .privacy-cards {
        display: grid;
        grid-template-columns: repeat(3, minmax(0, 1fr));
        gap: 16px;
    }

    .no-log-policy-section .info-grid,
    .encryption-protocol-section .info-grid,
    .risk-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }

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

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

    .footer-grid {
        grid-template-columns: 1.4fr repeat(3, minmax(0, 1fr));
    }

    .section,
    .feature-section {
        padding: 76px 0;
    }
}

@media (min-width: 1180px) {
    .main-nav a {
        padding: 9px 14px;
    }
}