:root {
    --primary: rgb(70,139,223);
    --primary-soft: rgba(70,139,223,.1);
    --primary-light: #eef6ff;
    --ink: #102033;
    --muted: #64748b;
    --line: #dbe7f5;
    --card: rgba(255,255,255,.88);
    --bg: #f6faff;
    --shadow: 0 18px 50px rgba(30, 80, 150, .10);
    --radius: 24px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    color: var(--ink);
    background: linear-gradient(180deg, #f7fbff 0%, #ffffff 42%, #f6faff 100%);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    line-height: 1.7;
    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;
}
.narrow {
    width: min(860px, calc(100% - 32px));
    margin: 0 auto;
}
.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255,255,255,.84);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(219,231,245,.8);
}
.nav-container {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    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: 760;
    letter-spacing: -.02em;
}
.logo-img { width: 38px; height: 38px; border-radius: 12px; }
.site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 68px;
    display: none;
    flex-direction: column;
    gap: 8px;
    padding: 14px;
    background: rgba(255,255,255,.96);
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: var(--shadow);
}
.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #42526b;
    font-size: 15px;
}
.site-nav a.active, .site-nav a:hover { color: var(--primary); background: var(--primary-soft); }
.nav-toggle { position: absolute; opacity: 0; pointer-events: none; }
.nav-toggle-label { display: grid; gap: 5px; cursor: pointer; padding: 10px; }
.nav-toggle-label span { width: 24px; height: 2px; background: #24425f; border-radius: 3px; }
.nav-toggle:checked ~ .site-nav { display: flex; }
section { padding: 56px 0; }
.centered-hero {
    padding: 76px 0 34px;
    text-align: center;
    background: radial-gradient(circle at 50% 0%, rgba(70,139,223,.18), transparent 48%);
}
.eyebrow, .category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    border-radius: 999px;
    background: var(--primary-soft);
    color: var(--primary);
    font-weight: 700;
    font-size: 13px;
}
h1, h2, h3 { line-height: 1.22; letter-spacing: -.035em; margin: 0; }
h1 { font-size: clamp(34px, 8vw, 68px); margin: 18px auto 18px; max-width: 880px; }
h2 { font-size: clamp(26px, 5vw, 42px); margin-bottom: 14px; }
h3 { font-size: 20px; margin-bottom: 8px; }
p { color: var(--muted); margin: 0 0 14px; }
.hero-copy { max-width: 760px; margin: 0 auto 24px; font-size: 17px; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: rgb(70,139,223);
    color: #fff;
    font-weight: 760;
    box-shadow: 0 14px 28px rgba(70,139,223,.25);
    transition: transform .18s ease, box-shadow .18s ease;
}
.download-btn:hover { transform: translateY(-2px); box-shadow: 0 18px 34px rgba(70,139,223,.28); }
.trust-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-top: 18px;
}
.trust-tags span, .pill {
    display: inline-flex;
    padding: 8px 12px;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: rgba(255,255,255,.74);
    color: #476176;
    font-size: 14px;
}
.product-bento {
    display: grid;
    gap: 16px;
    align-items: stretch;
}
.product-main-card, .bento-card, .category-card, .feature-card, .doc-card, .faq-item, .scenario-card, .stat-card, .security-principle, .download-panel {
    background: var(--card);
    border: 1px solid rgba(219,231,245,.9);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.product-main-card {
    padding: 22px;
    display: grid;
    place-items: center;
    min-height: 360px;
    background: linear-gradient(145deg, #ffffff, #eef6ff);
}
.product-main-card img {
    width: min(280px, 82%);
    margin: auto;
    filter: drop-shadow(0 22px 34px rgba(25,68,125,.18));
}
.status-stack { display: grid; gap: 14px; }
.stat-card { padding: 18px; }
.stat-card strong { display: block; color: #18344d; margin-bottom: 6px; }
.section-head { margin-bottom: 24px; max-width: 760px; }
.section-head.center { text-align: center; margin-left: auto; margin-right: auto; }
.feature-grid, .scenario-grid, .faq-grid, .info-grid { display: grid; gap: 16px; }
.feature-card, .scenario-card, .faq-item, .doc-card { padding: 20px; }
.feature-card .icon, .category-card .icon {
    width: 42px;
    height: 42px;
    display: grid;
    place-items: center;
    border-radius: 14px;
    background: var(--primary-soft);
    color: var(--primary);
    font-weight: 800;
    margin-bottom: 14px;
}
.roadmap {
    position: relative;
    display: grid;
    gap: 14px;
}
.roadmap-step {
    position: relative;
    display: grid;
    grid-template-columns: 42px 1fr;
    gap: 14px;
    padding: 18px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: rgba(255,255,255,.86);
}
.step-num {
    width: 38px;
    height: 38px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    font-weight: 800;
}
.text-link { color: var(--primary); font-weight: 720; }
.category-bento { display: grid; gap: 16px; }
.category-card { padding: 20px; display: flex; flex-direction: column; gap: 10px; min-height: 178px; }
.category-card.big { background: linear-gradient(145deg, #ffffff, #edf6ff); }
.bento-grid { display: grid; gap: 16px; }
.bento-card { padding: 22px; min-height: 190px; }
.bento-card.large { background: linear-gradient(145deg, #ffffff, #f0f7ff); }
.security-layout { display: grid; gap: 20px; align-items: center; }
.security-panel {
    padding: 24px;
    border-radius: 28px;
    background: linear-gradient(145deg, rgba(70,139,223,.10), rgba(255,255,255,.9));
    border: 1px solid var(--line);
}
.principle-list { display: grid; gap: 12px; margin-top: 16px; }
.security-principle { padding: 16px; box-shadow: none; }
.cta-section { padding: 38px 0 72px; }
.download-panel {
    padding: 34px 20px;
    text-align: center;
    background: linear-gradient(135deg, #ffffff, #edf6ff);
}
.page-hero {
    padding: 54px 0 28px;
    background: radial-gradient(circle at 20% 0, rgba(70,139,223,.14), transparent 34%);
}
.page-hero h1 { margin-left: 0; max-width: 800px; font-size: clamp(32px, 7vw, 54px); }
.page-summary { font-size: 17px; max-width: 760px; }
.doc-layout { display: grid; gap: 20px; align-items: start; }
.doc-content {
    padding: 24px;
    border: 1px solid var(--line);
    border-radius: 28px;
    background: rgba(255,255,255,.86);
    box-shadow: var(--shadow);
}
.doc-content h2 { font-size: 26px; margin-top: 18px; }
.steps-list { display: grid; gap: 12px; margin: 18px 0; }
.step-card {
    padding: 16px;
    border-radius: 18px;
    background: #f8fbff;
    border: 1px solid var(--line);
}
.notice {
    border-left: 4px solid var(--primary);
    background: var(--primary-soft);
    padding: 16px;
    border-radius: 16px;
    color: #38526d;
    margin: 18px 0;
}
ul.clean { padding-left: 20px; color: var(--muted); }
ul.clean li { margin: 8px 0; }
.side-stack { display: grid; gap: 14px; }
.faq-item details { cursor: pointer; }
.faq-item summary { font-weight: 780; color: #18344d; }
.faq-item p { margin-top: 10px; }
.install-steps { counter-reset: install; display: grid; gap: 12px; }
.install-steps .step-card::before {
    counter-increment: install;
    content: counter(install);
    display: inline-grid;
    place-items: center;
    width: 30px;
    height: 30px;
    margin-right: 8px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    font-weight: 800;
}
.site-footer {
    padding: 44px 0 24px;
    background: #0f2742;
    color: rgba(255,255,255,.82);
}
.site-footer p, .site-footer a { color: rgba(255,255,255,.68); }
.footer-grid { display: grid; gap: 24px; }
.footer-brand { font-weight: 820; font-size: 20px; margin-bottom: 10px; color: #fff; }
.site-footer h3 { font-size: 16px; color: #fff; margin-bottom: 10px; }
.site-footer a { display: block; margin: 7px 0; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.14); margin-top: 24px; padding-top: 18px; font-size: 13px; color: rgba(255,255,255,.55); }
@media (min-width: 720px) {
    section { padding: 72px 0; }
    .feature-grid, .scenario-grid, .faq-grid, .info-grid { grid-template-columns: repeat(2, 1fr); }
    .category-bento { grid-template-columns: repeat(2, 1fr); }
    .product-bento { grid-template-columns: 1.5fr .9fr; }
    .footer-grid { grid-template-columns: 1.4fr .8fr .8fr; }
}
@media (min-width: 980px) {
    .nav-toggle-label { display: none; }
    .site-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        padding: 0;
        border: 0;
        background: transparent;
        box-shadow: none;
    }
    .site-nav a { font-size: 14px; }
    .centered-hero { padding-top: 100px; }
    .product-main-card { min-height: 520px; }
    .status-stack { grid-template-columns: 1fr; }
    .roadmap { grid-template-columns: repeat(6, 1fr); gap: 12px; }
    .roadmap-step { grid-template-columns: 1fr; align-content: start; min-height: 210px; }
    .roadmap-step:nth-child(even) { transform: translateY(22px); }
    .category-bento { grid-template-columns: repeat(4, 1fr); }
    .category-card.big { grid-column: span 2; }
    .bento-grid { grid-template-columns: repeat(4, 1fr); }
    .bento-card.large { grid-column: span 2; min-height: 230px; }
    .bento-card.medium { grid-column: span 2; }
    .security-layout { grid-template-columns: 1fr .85fr; }
    .doc-layout { grid-template-columns: minmax(0, 1fr) 320px; }
    .doc-content { padding: 34px; }
}
@media (max-width: 420px) {
    .container, .narrow { width: min(100% - 24px, 1120px); }
    .download-btn { width: 100%; }
    .hero-copy, .page-summary { font-size: 16px; }
    .trust-tags { justify-content: flex-start; }
    .centered-hero { text-align: left; }
    .centered-hero h1, .centered-hero .hero-copy { margin-left: 0; }
}