* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #64748b;
    --light: #f6f8fc;
    --line: #e5eaf3;
    --white: #ffffff;
    --panel: #f9fbff;
    --radius-lg: 34px;
    --radius-md: 24px;
    --shadow-soft: 0 18px 55px rgba(32, 54, 102, 0.12);
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "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 {
    margin: 0 0 14px;
    line-height: 1.22;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(34px, 8vw, 64px);
}

h2 {
    font-size: clamp(26px, 5vw, 42px);
}

h3 {
    font-size: 20px;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
}

.header-inner {
    max-width: 1180px;
    margin: 0 auto;
    padding: 14px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #172554;
    font-size: 20px;
    flex: 0 0 auto;
}

.logo img {
    width: 40px;
    height: 40px;
    object-fit: cover;
    border-radius: 12px;
}

.nav-toggle {
    display: none;
}

.nav-toggle-label {
    width: 44px;
    height: 44px;
    display: grid;
    place-content: center;
    gap: 5px;
    border: 1px solid var(--line);
    border-radius: 14px;
    cursor: pointer;
}

.nav-toggle-label span {
    display: block;
    width: 20px;
    height: 2px;
    background: #334155;
    border-radius: 999px;
}

.site-nav {
    position: absolute;
    left: 20px;
    right: 20px;
    top: 72px;
    display: none;
    padding: 12px;
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: var(--shadow-soft);
}

.nav-toggle:checked ~ .site-nav {
    display: grid;
    gap: 4px;
}

.site-nav a {
    padding: 11px 13px;
    border-radius: 12px;
    color: #475569;
    font-size: 15px;
}

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

.container {
    width: min(1120px, calc(100% - 40px));
    margin: 0 auto;
}

.section {
    padding: 76px 0;
}

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

.eyebrow,
.badge {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 7px 12px;
    margin-bottom: 18px;
    border-radius: 999px;
    background: #eef5ff;
    color: var(--blue);
    font-weight: 700;
    font-size: 13px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #ffffff;
    font-weight: 800;
    box-shadow: 0 12px 26px rgba(41, 128, 254, 0.28);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 16px 32px rgba(23, 104, 232, 0.32);
}

.text-link {
    color: var(--blue);
    font-weight: 700;
}

.text-link:hover {
    color: var(--blue-dark);
}

.vpn-lab-hero {
    background: var(--gradient);
    color: #ffffff;
    padding: 72px 0 84px;
    position: relative;
    overflow: hidden;
}

.vpn-lab-hero::before,
.vpn-lab-hero::after {
    content: "";
    position: absolute;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.14);
    filter: blur(2px);
}

.vpn-lab-hero::before {
    width: 240px;
    height: 240px;
    right: -80px;
    top: 40px;
}

.vpn-lab-hero::after {
    width: 360px;
    height: 360px;
    left: -160px;
    bottom: -180px;
}

.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 42px;
    align-items: center;
}

.hero-copy p {
    color: rgba(255, 255, 255, 0.88);
    font-size: 17px;
    max-width: 640px;
}

.hero-tags,
.status-stack,
.inline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 24px 0 0;
}

.hero-tags span,
.status-stack span,
.inline-tags 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);
    font-size: 13px;
    color: rgba(255, 255, 255, 0.92);
}

.hero-visual {
    position: relative;
    min-height: 320px;
}

.hero-device {
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.16);
    padding: 18px;
    box-shadow: 0 24px 70px rgba(11, 22, 64, 0.22);
    border: 1px solid rgba(255, 255, 255, 0.18);
}

.hero-device img {
    width: 100%;
    border-radius: 26px;
}

.float-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.94);
    color: #172554;
    border-radius: 18px;
    padding: 11px 14px;
    box-shadow: 0 18px 45px rgba(15, 23, 42, 0.18);
    font-weight: 800;
    font-size: 13px;
}

.float-card small {
    display: block;
    color: #64748b;
    font-weight: 600;
}

.float-card.one { top: 14px; left: 8px; }
.float-card.two { top: 46%; right: 0; }
.float-card.three { bottom: 28px; left: 24px; }
.float-card.four { bottom: 8px; right: 36px; }

.privacy-summary {
    margin-top: -46px;
    position: relative;
    z-index: 2;
}

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

.summary-card,
.security-card,
.info-card,
.risk-card,
.faq-item,
.step-card,
.tip-box,
.article-panel {
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    box-shadow: 0 14px 45px rgba(15, 23, 42, 0.06);
}

.summary-card {
    padding: 24px;
}

.summary-card .mark {
    display: inline-flex;
    width: 36px;
    height: 36px;
    margin-bottom: 14px;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    background: #eef5ff;
    color: var(--blue);
    font-weight: 900;
}

.split-section {
    display: grid;
    gap: 34px;
    align-items: center;
}

.visual-panel,
.safety-panel,
.tech-panel {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-soft);
}

.visual-panel img {
    margin: 0 auto;
    border-radius: 26px;
}

.feature-list,
.clean-list {
    display: grid;
    gap: 12px;
    padding: 0;
    margin: 20px 0 0;
    list-style: none;
}

.feature-list li,
.clean-list li {
    position: relative;
    padding-left: 28px;
    color: #475569;
}

.feature-list li::before,
.clean-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 10px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: 0 0 0 5px #eaf3ff;
}

.privacy-protection-section .panel-grid,
.no-log-policy-section .panel-grid,
.encryption-protocol-section .panel-grid {
    display: grid;
    gap: 18px;
}

.info-card {
    padding: 22px;
}

.info-card strong {
    color: #172554;
}

.high-speed-section {
    background: #f3f7ff;
}

.device-grid,
.node-grid,
.risk-grid,
.faq-grid,
.card-grid {
    display: grid;
    gap: 18px;
}

.device-card,
.node-card {
    padding: 22px;
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: 24px;
}

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

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

.step-number {
    display: inline-grid;
    place-items: center;
    width: 38px;
    height: 38px;
    margin-bottom: 12px;
    border-radius: 14px;
    background: #eef5ff;
    color: var(--blue);
    font-weight: 900;
}

.risk-card {
    padding: 22px;
    border-left: 5px solid #2980FE;
}

.faq-item {
    padding: 22px;
}

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

.cta-section {
    padding: 76px 0;
    background: var(--gradient);
    color: #ffffff;
    text-align: center;
}

.cta-section p {
    color: rgba(255, 255, 255, 0.88);
    max-width: 720px;
    margin: 0 auto 24px;
}

.page-hero {
    padding: 62px 0;
    background: linear-gradient(180deg, #f8fbff 0%, #ffffff 100%);
    border-bottom: 1px solid var(--line);
}

.page-hero .container {
    max-width: 920px;
}

.page-hero p {
    font-size: 17px;
    color: var(--muted);
}

.article-layout {
    display: grid;
    gap: 24px;
    align-items: start;
}

.article-main {
    display: grid;
    gap: 22px;
}

.article-panel {
    padding: 24px;
}

.article-panel h2 {
    font-size: 26px;
}

.side-panel {
    background: #f7faff;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 22px;
}

.side-panel a {
    display: block;
    padding: 10px 0;
    color: var(--blue);
    font-weight: 700;
    border-bottom: 1px solid #e8eef8;
}

.side-panel a:last-child {
    border-bottom: 0;
}

.check-list {
    display: grid;
    gap: 12px;
    margin: 18px 0 0;
    padding: 0;
    list-style: none;
}

.check-list li {
    padding: 14px 16px;
    border-radius: 16px;
    background: #f7faff;
    border: 1px solid #e7edf7;
}

.download-center {
    text-align: center;
    padding: 34px;
    background: #ffffff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
}

.download-center .download-btn {
    margin-top: 10px;
}

.site-footer {
    background: #111827;
    color: #d1d5db;
}

.footer-inner {
    width: min(1120px, calc(100% - 40px));
    margin: 0 auto;
    padding: 54px 0;
    display: grid;
    gap: 36px;
}

.footer-logo {
    color: #ffffff;
}

.footer-brand p {
    color: #aeb7c5;
    max-width: 420px;
}

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

.footer-links h3 {
    color: #ffffff;
    font-size: 16px;
}

.footer-links a {
    display: block;
    color: #aeb7c5;
    margin: 8px 0;
}

.footer-links a:hover {
    color: #ffffff;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    padding: 18px 20px;
    color: #9ca3af;
}

@media (min-width: 760px) {
    .summary-grid,
    .device-grid,
    .node-grid,
    .card-grid {
        grid-template-columns: repeat(3, 1fr);
    }

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

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

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

@media (min-width: 980px) {
    .nav-toggle-label {
        display: none;
    }

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

    .site-nav a {
        font-size: 14px;
    }

    .hero-grid,
    .split-section,
    .article-layout {
        grid-template-columns: 1.05fr 0.95fr;
    }

    .privacy-protection-section .panel-grid,
    .no-log-policy-section .panel-grid,
    .encryption-protocol-section .panel-grid {
        grid-template-columns: repeat(3, 1fr);
    }

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

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

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

    .footer-inner {
        grid-template-columns: 0.9fr 1.1fr;
    }
}

@media (max-width: 520px) {
    .container,
    .footer-inner {
        width: min(100% - 28px, 1120px);
    }

    .section {
        padding: 56px 0;
    }

    .vpn-lab-hero {
        padding: 54px 0 72px;
    }

    .float-card {
        position: static;
        margin-top: 10px;
        display: inline-block;
    }

    .hero-visual {
        min-height: auto;
    }

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