* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #667085;
    --light: #f5f7fb;
    --lighter: #f8fbff;
    --border: #e5eaf3;
    --card: #ffffff;
    --shadow: 0 18px 45px rgba(22, 37, 82, 0.08);
    --radius: 28px;
}

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: 1.7;
    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 {
    line-height: 1.25;
    margin: 0 0 16px;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(34px, 8vw, 66px);
}

h2 {
    font-size: clamp(26px, 4.5vw, 44px);
}

h3 {
    font-size: 20px;
}

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(229, 234, 243, 0.9);
}

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

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #111827;
    white-space: nowrap;
}

.logo-img {
    width: 38px;
    height: 38px;
    border-radius: 12px;
    object-fit: cover;
    box-shadow: 0 8px 20px rgba(41, 128, 254, 0.18);
}

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

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

.nav-toggle-label span {
    display: block;
    width: 18px;
    height: 2px;
    background: #1f2937;
    border-radius: 10px;
}

.main-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 74px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 20px;
    box-shadow: var(--shadow);
}

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

.main-nav a {
    padding: 10px 12px;
    color: #344054;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 600;
}

.main-nav a:hover,
.main-nav a.active {
    background: #eff6ff;
    color: var(--blue);
}

.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: 800;
    box-shadow: 0 12px 28px rgba(41, 128, 254, 0.28);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    background: var(--blue-dark);
    transform: translateY(-2px);
    box-shadow: 0 16px 32px rgba(23, 104, 232, 0.32);
}

.section {
    padding: 74px 0;
}

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

.section-heading {
    max-width: 760px;
    margin-bottom: 34px;
}

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

.section-kicker,
.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    margin-bottom: 14px;
    border-radius: 999px;
    background: #eef5ff;
    color: var(--blue);
    font-size: 13px;
    font-weight: 800;
}

.section-kicker::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--blue);
}

.section-heading p,
.hero-copy p,
.feature-copy p,
.page-hero p {
    color: var(--muted);
    font-size: 16px;
}

.vpn-saas-hero {
    position: relative;
    padding: 54px 0 68px;
    color: #fff;
    background: var(--gradient);
    overflow: hidden;
}

.vpn-saas-hero::after {
    content: "";
    position: absolute;
    left: -10%;
    right: -10%;
    bottom: -68px;
    height: 140px;
    background: #fff;
    transform: rotate(-3deg);
    transform-origin: center;
}

.vpn-saas-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 16% 25%, rgba(255,255,255,0.22), transparent 30%),
        radial-gradient(circle at 82% 8%, rgba(255,255,255,0.18), transparent 26%);
}

.hero-grid {
    position: relative;
    z-index: 2;
    display: grid;
    gap: 38px;
    align-items: center;
}

.hero-copy {
    max-width: 720px;
}

.hero-copy p {
    color: rgba(255, 255, 255, 0.88);
    font-size: 18px;
}

.hero-tags,
.float-tags,
.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 18px 0 26px;
}

.hero-tags span,
.float-tags span,
.tag-list span {
    display: inline-flex;
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.24);
    color: #fff;
    font-size: 13px;
    font-weight: 700;
}

.hero-card {
    position: relative;
    max-width: 520px;
    margin: 0 auto;
}

.product-frame {
    padding: 22px;
    border-radius: 38px;
    background: rgba(255, 255, 255, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.24);
    box-shadow: 0 26px 70px rgba(26, 35, 98, 0.28);
    backdrop-filter: blur(16px);
}

.product-frame img {
    border-radius: 30px;
    background: #fff;
}

.status-card {
    position: absolute;
    display: none;
    min-width: 132px;
    padding: 12px 14px;
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.94);
    color: #1f2937;
    font-weight: 800;
    box-shadow: 0 18px 40px rgba(22, 37, 82, 0.16);
}

.status-card small {
    display: block;
    color: var(--muted);
    font-weight: 600;
}

.status-card.one { top: 10%; left: -8%; }
.status-card.two { right: -8%; top: 38%; }
.status-card.three { bottom: 8%; left: 4%; }

.product-highlights {
    margin-top: -24px;
    position: relative;
    z-index: 5;
}

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

.highlight-card,
.info-card,
.risk-card,
.faq-item,
.step-card,
.content-card,
.side-panel,
.policy-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 24px;
    box-shadow: var(--shadow);
}

.highlight-card {
    padding: 22px;
}

.highlight-card .label,
.info-card .label {
    display: inline-flex;
    color: var(--blue);
    background: #eef5ff;
    padding: 5px 10px;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 800;
    margin-bottom: 12px;
}

.highlight-card p,
.info-card p,
.risk-card p,
.step-card p,
.content-card p,
.policy-card p {
    color: var(--muted);
}

.text-link {
    display: inline-flex;
    align-items: center;
    color: var(--blue);
    font-weight: 800;
    margin-top: 6px;
}

.text-link::after {
    content: "›";
    margin-left: 6px;
}

.feature-panel {
    display: grid;
    gap: 24px;
    align-items: center;
    padding: 22px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.feature-panel.reverse {
    background: #f8fbff;
}

.feature-copy ul,
.content-card ul,
.checklist {
    margin: 18px 0;
    padding: 0;
    list-style: none;
}

.feature-copy li,
.content-card li,
.checklist li {
    position: relative;
    padding-left: 26px;
    margin: 9px 0;
    color: #344054;
}

.feature-copy li::before,
.content-card li::before,
.checklist li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: 0 0 0 4px #e8f2ff;
}

.feature-image {
    position: relative;
    overflow: hidden;
    border-radius: 26px;
    background: linear-gradient(180deg, #eef5ff, #ffffff);
    padding: 18px;
}

.feature-image img {
    border-radius: 22px;
    margin: 0 auto;
}

.speed-metrics {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
    margin-top: 18px;
}

.metric {
    padding: 16px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 18px;
}

.metric strong {
    display: block;
    color: var(--blue);
    font-size: 20px;
}

.nodes-layout,
.privacy-layout,
.device-layout,
.protocol-layout {
    display: grid;
    gap: 22px;
    align-items: center;
}

.info-grid,
.policy-grid,
.risk-grid,
.faq-grid,
.related-grid {
    display: grid;
    gap: 16px;
}

.info-card,
.policy-card {
    padding: 22px;
}

.privacy-board {
    padding: 24px;
    border-radius: var(--radius);
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.privacy-board img {
    border-radius: 24px;
    margin-top: 18px;
}

.no-log-policy-section .policy-grid {
    margin-top: 20px;
}

.multi-device-section .device-card {
    padding: 22px;
    border-radius: var(--radius);
    background: var(--gradient);
    color: #fff;
    box-shadow: 0 22px 50px rgba(53, 88, 242, 0.18);
}

.device-card p {
    color: rgba(255, 255, 255, 0.86);
}

.device-card img {
    border-radius: 24px;
    margin-top: 18px;
}

.protocol-panel {
    padding: 24px;
    border-radius: var(--radius);
    background:
        linear-gradient(135deg, rgba(41,128,254,0.08), rgba(184,77,218,0.08)),
        #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.protocol-line {
    display: grid;
    gap: 12px;
    margin-top: 16px;
}

.protocol-line div {
    padding: 16px;
    border-radius: 18px;
    background: #fff;
    border: 1px solid var(--border);
}

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

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

.step-number {
    width: 38px;
    height: 38px;
    display: grid;
    place-items: center;
    margin-bottom: 12px;
    border-radius: 14px;
    color: #fff;
    font-weight: 900;
    background: var(--blue);
}

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

.risk-card strong {
    display: block;
    margin: 10px 0 4px;
    color: #111827;
}

.faq-item {
    padding: 22px;
}

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

.cta-section {
    padding: 72px 0;
    color: #fff;
    background: var(--gradient);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 18% 20%, rgba(255,255,255,0.22), transparent 28%);
}

.cta-section .container {
    position: relative;
    z-index: 2;
    max-width: 760px;
}

.cta-section p {
    color: rgba(255,255,255,0.9);
    margin-bottom: 22px;
}

.page-hero {
    padding: 64px 0 42px;
    background:
        linear-gradient(180deg, #f8fbff 0%, #ffffff 100%);
    border-bottom: 1px solid var(--border);
}

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

.article-layout {
    display: grid;
    gap: 22px;
    align-items: start;
    padding: 54px 0 76px;
}

.article-main {
    display: grid;
    gap: 20px;
}

.content-card {
    padding: 24px;
}

.content-card.accent {
    background:
        linear-gradient(135deg, rgba(41, 128, 254, 0.07), rgba(123, 78, 241, 0.06)),
        #fff;
}

.side-panel {
    padding: 22px;
    position: sticky;
    top: 92px;
}

.side-panel h3 {
    color: #111827;
}

.side-panel a:not(.download-btn) {
    display: block;
    padding: 10px 0;
    color: var(--blue);
    font-weight: 700;
    border-bottom: 1px solid var(--border);
}

.tip-box {
    padding: 18px;
    border-radius: 20px;
    background: #f3f8ff;
    border: 1px solid #dbeafe;
    color: #344054;
}

.download-centered {
    text-align: center;
    padding: 24px;
}

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

.download-steps li {
    list-style: none;
    position: relative;
    padding: 18px 18px 18px 60px;
    border-radius: 20px;
    background: #fff;
    border: 1px solid var(--border);
}

.download-steps li::before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 18px;
    top: 18px;
    width: 28px;
    height: 28px;
    border-radius: 10px;
    background: var(--blue);
    color: #fff;
    display: grid;
    place-items: center;
    font-weight: 800;
}

.site-footer {
    background: #111827;
    color: #d1d5db;
    padding: 56px 0 26px;
}

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

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

.site-footer a:not(.brand) {
    display: block;
    color: #d1d5db;
    margin: 8px 0;
}

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

.footer-brand p {
    max-width: 360px;
    color: #aeb7c5;
}

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

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    margin-top: 34px;
    padding-top: 18px;
    color: #aeb7c5;
    font-size: 14px;
}

@media (min-width: 640px) {
    .container {
        width: min(100% - 48px, 1180px);
    }

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

    .speed-metrics,
    .protocol-line {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .footer-grid {
        grid-template-columns: 1.4fr 1fr 1fr 1fr;
    }
}

@media (min-width: 920px) {
    .site-header {
        position: sticky;
    }

    .nav-toggle-label {
        display: none;
    }

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

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

    .vpn-saas-hero {
        padding: 86px 0 104px;
    }

    .hero-grid,
    .feature-panel,
    .nodes-layout,
    .privacy-layout,
    .device-layout,
    .protocol-layout,
    .article-layout {
        grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    }

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

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

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

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

    .status-card {
        display: block;
    }

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

    .page-hero {
        padding: 82px 0 54px;
    }
}

@media (min-width: 1120px) {
    .main-nav a {
        padding: 9px 13px;
    }

    .feature-panel,
    .privacy-board,
    .protocol-panel {
        padding: 34px;
    }
}