:root {
    --primary: rgb(70,139,223);
    --primary-dark: #1f5ea8;
    --primary-soft: #eef6ff;
    --ink: #102033;
    --muted: #607086;
    --line: #d9e8f8;
    --card: rgba(255,255,255,0.88);
    --bg: #f6fbff;
    --shadow: 0 18px 50px rgba(32, 94, 168, 0.12);
    --radius: 22px;
}
* { 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: var(--ink);
    background:
        radial-gradient(circle at 10% 0%, rgba(70,139,223,0.14), transparent 30%),
        radial-gradient(circle at 95% 10%, rgba(70,139,223,0.10), transparent 28%),
        linear-gradient(180deg, #f8fcff 0%, #f2f8ff 48%, #ffffff 100%);
    line-height: 1.72;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    backdrop-filter: blur(18px);
    background: rgba(255,255,255,0.86);
    border-bottom: 1px solid rgba(217,232,248,0.85);
}
.nav-wrap { min-height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: -0.02em; color: #15375d; }
.logo img { width: 36px; height: 36px; border-radius: 12px; box-shadow: 0 8px 20px rgba(70,139,223,0.22); }
.nav-toggle {
    border: 1px solid var(--line);
    background: #fff;
    color: var(--primary-dark);
    border-radius: 999px;
    padding: 8px 14px;
    font-weight: 700;
}
.site-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #fff;
    box-shadow: var(--shadow);
}
.site-nav.open { display: flex; }
.site-nav a { padding: 10px 12px; border-radius: 12px; color: #38506b; font-size: 15px; }
.site-nav a.active, .site-nav a:hover { background: var(--primary-soft); color: var(--primary-dark); }
.hero {
    padding: 46px 0 34px;
}
.hero-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 28px;
    align-items: center;
}
.eyebrow, .badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    width: fit-content;
    padding: 6px 12px;
    border: 1px solid rgba(70,139,223,0.22);
    background: rgba(238,246,255,0.88);
    color: var(--primary-dark);
    border-radius: 999px;
    font-size: 13px;
    font-weight: 700;
}
h1, h2, h3 { line-height: 1.22; margin: 0 0 14px; color: #112945; }
h1 { font-size: clamp(32px, 7vw, 58px); letter-spacing: -0.05em; margin-top: 18px; }
h2 { font-size: clamp(26px, 4vw, 38px); letter-spacing: -0.035em; }
h3 { font-size: 20px; letter-spacing: -0.02em; }
p { margin: 0 0 16px; color: var(--muted); }
.hero-desc { font-size: 17px; max-width: 620px; color: #4f6178; }
.hero-tags, .tag-row { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0 24px; }
.tag, .mini-tag {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 7px 12px;
    color: #38506b;
    font-size: 13px;
    box-shadow: 0 8px 20px rgba(70,139,223,0.06);
}
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    min-width: 138px;
    padding: 12px 24px;
    border-radius: 999px;
    background: var(--primary);
    color: #fff;
    font-weight: 800;
    box-shadow: 0 16px 30px rgba(70,139,223,0.28);
    transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.download-btn:hover { transform: translateY(-2px); background: var(--primary-dark); box-shadow: 0 20px 36px rgba(70,139,223,0.32); }
.hero-visual {
    position: relative;
    min-height: 420px;
    border-radius: 32px;
    padding: 22px;
    background: linear-gradient(145deg, rgba(255,255,255,0.9), rgba(235,246,255,0.82));
    border: 1px solid rgba(255,255,255,0.95);
    box-shadow: var(--shadow);
    overflow: hidden;
}
.hero-visual:before {
    content: "";
    position: absolute;
    inset: 50px -80px auto auto;
    width: 220px;
    height: 220px;
    background: radial-gradient(circle, rgba(70,139,223,0.26), transparent 70%);
}
.app-frame { position: relative; display: grid; place-items: center; min-height: 310px; }
.app-frame img { max-height: 330px; margin: 0 auto; filter: drop-shadow(0 28px 45px rgba(32,94,168,0.18)); }
.status-card {
    position: absolute;
    left: 18px;
    top: 22px;
    width: min(220px, 58%);
    padding: 14px;
    background: rgba(255,255,255,0.92);
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: 0 14px 30px rgba(32,94,168,0.12);
}
.status-dot { width: 10px; height: 10px; border-radius: 50%; background: #26b878; display: inline-block; margin-right: 6px; }
.visual-labels { position: relative; display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.section { padding: 42px 0; }
.section-head { max-width: 720px; margin-bottom: 24px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.trust-grid, .category-grid, .feature-grid, .scenario-grid, .info-grid, .guide-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}
.trust-item, .category-card, .feature-card, .scenario-card, .info-card, .guide-card, .faq-item, .note-card, .step, .security-card {
    background: var(--card);
    border: 1px solid rgba(217,232,248,0.92);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: 0 12px 28px rgba(32,94,168,0.07);
}
.trust-item strong { display: block; color: #15375d; font-size: 18px; margin-bottom: 4px; }
.category-card { transition: transform .2s ease, border-color .2s ease; }
.category-card:hover { transform: translateY(-3px); border-color: rgba(70,139,223,0.46); }
.category-card span { color: var(--primary-dark); font-weight: 800; font-size: 13px; }
.category-card p { margin-bottom: 0; }
.feature-card .icon, .guide-card .icon {
    width: 42px;
    height: 42px;
    border-radius: 15px;
    display: grid;
    place-items: center;
    background: var(--primary-soft);
    color: var(--primary-dark);
    font-weight: 900;
    margin-bottom: 14px;
}
.security-layout, .split-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    align-items: center;
}
.security-panel {
    border-radius: 28px;
    padding: 22px;
    background: linear-gradient(145deg, #ffffff, #edf6ff);
    border: 1px solid rgba(217,232,248,0.95);
    box-shadow: var(--shadow);
}
.security-list { display: grid; gap: 12px; margin: 0; padding: 0; list-style: none; }
.security-list li { padding: 14px; border-radius: 16px; background: rgba(255,255,255,0.82); border: 1px solid var(--line); color: #40566f; }
.steps { display: grid; grid-template-columns: 1fr; gap: 14px; counter-reset: step; }
.step { position: relative; padding-top: 48px; }
.step:before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    top: 18px;
    left: 20px;
    width: 28px;
    height: 28px;
    border-radius: 10px;
    display: grid;
    place-items: center;
    background: var(--primary);
    color: #fff;
    font-weight: 900;
}
.faq-list { display: grid; gap: 14px; }
.faq-item h3 { margin-bottom: 8px; }
.cta-section {
    text-align: center;
    border-radius: 32px;
    padding: 36px 22px;
    background:
        radial-gradient(circle at 20% 20%, rgba(70,139,223,0.18), transparent 34%),
        linear-gradient(135deg, #f7fbff, #eaf5ff);
    border: 1px solid rgba(217,232,248,0.95);
    box-shadow: var(--shadow);
}
.page-hero { padding: 42px 0 24px; }
.page-hero .container {
    border-radius: 30px;
    padding: 28px;
    background: linear-gradient(135deg, rgba(255,255,255,0.95), rgba(237,246,255,0.9));
    border: 1px solid rgba(217,232,248,0.92);
    box-shadow: var(--shadow);
}
.article-layout { display: grid; grid-template-columns: 1fr; gap: 18px; align-items: start; }
.article-body {
    background: rgba(255,255,255,0.86);
    border: 1px solid var(--line);
    border-radius: 24px;
    padding: 24px;
    box-shadow: 0 12px 28px rgba(32,94,168,0.06);
}
.article-aside { display: grid; gap: 14px; }
.check-list { margin: 0; padding-left: 20px; color: #4f6178; }
.check-list li { margin: 8px 0; }
.notice {
    padding: 16px;
    border-left: 4px solid var(--primary);
    background: var(--primary-soft);
    border-radius: 16px;
    color: #38506b;
    margin: 18px 0;
}
.download-panel { margin-top: 20px; }
.site-footer { margin-top: 42px; padding: 38px 0 18px; background: #102a45; color: #e7f2ff; }
.site-footer p, .site-footer a { color: #b9cce0; }
.footer-grid { display: grid; grid-template-columns: 1fr; gap: 24px; }
.footer-logo { font-size: 20px; font-weight: 900; margin-bottom: 8px; }
.site-footer h3 { color: #fff; font-size: 16px; margin-bottom: 10px; }
.site-footer a { display: block; margin: 8px 0; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.12); margin-top: 24px; padding-top: 16px; color: #9fb6cd; font-size: 13px; }
@media (min-width: 640px) {
    .trust-grid, .category-grid, .feature-grid, .scenario-grid, .info-grid, .guide-grid { grid-template-columns: repeat(2, 1fr); }
    .steps { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 920px) {
    .nav-toggle { display: none; }
    .site-nav { position: static; display: flex; flex-direction: row; padding: 0; border: 0; box-shadow: none; background: transparent; align-items: center; }
    .site-nav a { padding: 8px 11px; }
    .hero { padding: 72px 0 48px; }
    .hero-layout { grid-template-columns: 1.02fr .98fr; gap: 42px; }
    .category-grid, .feature-grid, .scenario-grid, .guide-grid { grid-template-columns: repeat(3, 1fr); }
    .trust-grid { grid-template-columns: repeat(4, 1fr); }
    .security-layout, .split-layout { grid-template-columns: 1fr 1fr; gap: 38px; }
    .steps { grid-template-columns: repeat(4, 1fr); }
    .article-layout { grid-template-columns: minmax(0, 1fr) 330px; gap: 22px; }
    .footer-grid { grid-template-columns: 1.4fr .8fr .8fr; }
}
@media (min-width: 1120px) {
    .section { padding: 54px 0; }
    .page-hero .container { padding: 36px; }
}