:root {
    --primary: rgb(70,139,223);
    --primary-dark: #2562a8;
    --primary-soft: #eaf4ff;
    --text: #13213a;
    --muted: #63718a;
    --line: #dce8f7;
    --card: #ffffff;
    --bg: #f6faff;
    --shadow: 0 18px 45px rgba(70, 139, 223, .12);
    --radius: 22px;
}
* { box-sizing: border-box; }
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: linear-gradient(180deg, #eef7ff 0%, #ffffff 42%, #f7fbff 100%);
    line-height: 1.72;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.container {
    width: min(100% - 32px, 1160px);
    margin: 0 auto;
}
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,.88);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(220,232,247,.9);
}
.nav-shell {
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #10233f;
    letter-spacing: .02em;
}
.logo { width: 40px; height: 40px; border-radius: 12px; }
.nav-toggle { display: none; }
.nav-toggle-label {
    width: 42px;
    height: 42px;
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: #fff;
}
.nav-toggle-label span {
    width: 20px;
    height: 2px;
    background: #20304d;
    border-radius: 20px;
}
.main-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    display: none;
    flex-direction: column;
    gap: 8px;
    padding: 16px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: var(--shadow);
}
.nav-toggle:checked ~ .main-nav { display: flex; }
.main-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #34435d;
    font-size: 15px;
}
.main-nav a.active,
.main-nav a:hover { background: var(--primary-soft); color: var(--primary-dark); }
section { padding: 54px 0; }
.hero {
    position: relative;
    padding: 58px 0 44px;
    background:
        radial-gradient(circle at 8% 12%, rgba(70,139,223,.20), transparent 34%),
        radial-gradient(circle at 90% 18%, rgba(120,183,255,.22), transparent 30%);
}
.hero-layout {
    display: grid;
    gap: 34px;
    align-items: center;
}
.eyebrow,
.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    color: var(--primary-dark);
    background: rgba(70,139,223,.11);
    border: 1px solid rgba(70,139,223,.18);
    font-weight: 700;
    font-size: 13px;
}
h1, h2, h3 { line-height: 1.25; margin: 0 0 14px; }
h1 { font-size: clamp(32px, 8vw, 58px); letter-spacing: -.04em; }
h2 { font-size: clamp(26px, 5vw, 38px); letter-spacing: -.03em; }
h3 { font-size: 20px; }
p { margin: 0 0 16px; color: var(--muted); }
.hero-copy p { font-size: 17px; max-width: 640px; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: var(--primary);
    color: #fff;
    font-weight: 800;
    letter-spacing: .02em;
    box-shadow: 0 14px 28px rgba(70,139,223,.28);
    transition: transform .2s ease, box-shadow .2s ease;
    white-space: nowrap;
}
.download-btn:hover { transform: translateY(-2px); box-shadow: 0 18px 34px rgba(70,139,223,.34); }
.hero-actions { margin-top: 24px; display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.micro-note { color: #738198; font-size: 13px; }
.tag-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.tag-row span {
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,.76);
    border: 1px solid var(--line);
    color: #40516f;
    font-size: 13px;
}
.product-visual {
    position: relative;
    display: grid;
    place-items: center;
    min-height: 420px;
    padding: 22px;
    border-radius: 32px;
    background: linear-gradient(145deg, rgba(255,255,255,.92), rgba(232,244,255,.72));
    border: 1px solid rgba(255,255,255,.8);
    box-shadow: var(--shadow);
}
.app-frame {
    width: min(290px, 76vw);
    padding: 16px;
    border-radius: 34px;
    background: linear-gradient(180deg, #fff, #edf6ff);
    box-shadow: 0 24px 55px rgba(22, 45, 82, .16);
}
.status-card, .floating-chip {
    position: absolute;
    background: rgba(255,255,255,.92);
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: 0 14px 34px rgba(24, 58, 105, .12);
    padding: 12px 14px;
}
.status-card { left: 12px; bottom: 28px; width: 180px; }
.status-card strong { display: block; color: #16335c; }
.status-card span { color: #65758f; font-size: 13px; }
.floating-chip { right: 12px; top: 30px; font-weight: 700; color: var(--primary-dark); font-size: 13px; }
.trust-strip {
    display: grid;
    gap: 14px;
    grid-template-columns: 1fr;
    margin-top: -18px;
    position: relative;
    z-index: 2;
}
.trust-item {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 18px;
    box-shadow: 0 14px 30px rgba(70,139,223,.08);
}
.trust-item strong { display: block; color: #13294a; }
.section-head {
    max-width: 760px;
    margin-bottom: 26px;
}
.section-head.center { text-align: center; margin-left: auto; margin-right: auto; }
.grid, .feature-grid, .category-grid, .scenario-grid, .faq-grid {
    display: grid;
    gap: 18px;
}
.card, .category-card, .feature-card, .scenario-card, .faq-item, .tip-card, .step-card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: 0 12px 34px rgba(70,139,223,.08);
}
.category-card { display: flex; flex-direction: column; min-height: 190px; }
.category-card a, .text-link {
    margin-top: auto;
    color: var(--primary-dark);
    font-weight: 800;
}
.feature-card .icon, .category-card .icon, .scenario-card .icon {
    width: 42px;
    height: 42px;
    display: grid;
    place-items: center;
    border-radius: 14px;
    color: var(--primary-dark);
    background: var(--primary-soft);
    margin-bottom: 16px;
    font-weight: 900;
}
.split, .security-layout, .article-layout {
    display: grid;
    gap: 24px;
    align-items: center;
}
.security-panel {
    background: linear-gradient(145deg, #ffffff, #edf7ff);
    border: 1px solid var(--line);
    border-radius: 28px;
    padding: 24px;
    box-shadow: var(--shadow);
}
.security-list { list-style: none; padding: 0; margin: 18px 0 0; display: grid; gap: 12px; }
.security-list li {
    padding: 13px 14px;
    border-radius: 15px;
    background: rgba(255,255,255,.76);
    border: 1px solid rgba(220,232,247,.9);
    color: #35445f;
}
.steps { display: grid; gap: 16px; counter-reset: step; }
.step-card { position: relative; padding-top: 50px; }
.step-card::before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 20px;
    top: 18px;
    width: 28px;
    height: 28px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    color: #fff;
    background: var(--primary);
    font-weight: 800;
}
.faq-item h3 { font-size: 17px; margin-bottom: 8px; }
.cta-section {
    text-align: center;
    background: linear-gradient(135deg, rgba(70,139,223,.12), rgba(255,255,255,.88));
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}
.article-hero {
    padding: 48px 0 24px;
    background: radial-gradient(circle at 10% 10%, rgba(70,139,223,.18), transparent 34%);
}
.article-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 28px;
    padding: 24px;
    box-shadow: var(--shadow);
}
.article-card p { color: #52627c; }
.info-panel {
    border-radius: 24px;
    padding: 22px;
    background: linear-gradient(145deg, #eef7ff, #ffffff);
    border: 1px solid var(--line);
}
.check-list, .plain-list { margin: 0; padding-left: 20px; color: #52627c; }
.check-list li, .plain-list li { margin: 8px 0; }
.notice {
    border-left: 4px solid var(--primary);
    background: var(--primary-soft);
    padding: 16px 18px;
    border-radius: 16px;
    color: #34435d;
}
.download-panel {
    display: grid;
    gap: 20px;
    align-items: center;
    background: linear-gradient(135deg, #fff, #eef7ff);
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 26px;
    box-shadow: var(--shadow);
}
.site-footer {
    padding: 46px 0 24px;
    background: #0f2746;
    color: #d8e8fb;
}
.footer-grid { display: grid; gap: 24px; }
.footer-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.footer-brand img { width: 38px; height: 38px; border-radius: 12px; }
.site-footer p { color: #aebfd5; }
.site-footer h3 { color: #fff; font-size: 16px; }
.site-footer a { display: block; color: #c8d8ec; margin: 8px 0; font-size: 14px; }
.footer-bottom {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding-top: 24px;
    margin-top: 28px;
    border-top: 1px solid rgba(255,255,255,.12);
    color: #9fb3cb;
    font-size: 13px;
}
@media (min-width: 640px) {
    .trust-strip { grid-template-columns: repeat(2, 1fr); }
    .category-grid, .feature-grid, .scenario-grid, .faq-grid, .grid { grid-template-columns: repeat(2, 1fr); }
    .download-panel { grid-template-columns: 1fr auto; }
}
@media (min-width: 900px) {
    .nav-toggle-label { display: none; }
    .main-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        padding: 0;
        box-shadow: none;
        border: 0;
        background: transparent;
        gap: 4px;
    }
    .main-nav a { padding: 8px 12px; }
    .hero { padding: 86px 0 72px; }
    .hero-layout { grid-template-columns: 1.05fr .95fr; gap: 52px; }
    .trust-strip { grid-template-columns: repeat(4, 1fr); }
    .category-grid, .feature-grid, .scenario-grid { grid-template-columns: repeat(3, 1fr); }
    .faq-grid { grid-template-columns: repeat(2, 1fr); }
    .security-layout, .split, .article-layout { grid-template-columns: 1fr 1fr; }
    .steps { grid-template-columns: repeat(4, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
    .footer-bottom { flex-direction: row; justify-content: space-between; }
    section { padding: 72px 0; }
    .article-hero { padding: 70px 0 34px; }
}
@media (min-width: 1120px) {
    .status-card { left: -10px; }
    .floating-chip { right: -12px; }
}