* {
    box-sizing: border-box;
}

:root {
    --primary: rgb(70,139,223);
    --primary-dark: #245fba;
    --primary-soft: #edf6ff;
    --ink: #17233f;
    --muted: #64748b;
    --line: rgba(70, 139, 223, .14);
    --card: rgba(255, 255, 255, .92);
    --shadow: 0 14px 38px rgba(33, 80, 150, .10);
    --radius-lg: 24px;
    --radius-md: 18px;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--ink);
    background:
        radial-gradient(circle at 14% 4%, rgba(70, 139, 223, .18), transparent 34%),
        linear-gradient(180deg, #f3f9ff 0%, #ffffff 42%, #f7fbff 100%);
    line-height: 1.72;
    font-size: 16px;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
    display: block;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    padding: 12px 14px 8px;
    background: rgba(246, 250, 255, .86);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(70, 139, 223, .10);
}

.header-inner {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    letter-spacing: -.02em;
    color: #10223f;
}

.logo img {
    width: 36px;
    height: 36px;
    border-radius: 12px;
    box-shadow: 0 8px 22px rgba(70, 139, 223, .24);
}

.mobile-nav {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    background: rgba(255, 255, 255, .72);
    border: 1px solid rgba(70, 139, 223, .12);
    padding: 6px;
    border-radius: 18px;
}

.mobile-nav a {
    display: block;
    text-align: center;
    padding: 8px 6px;
    border-radius: 13px;
    color: #36506f;
    font-size: 13px;
    font-weight: 700;
}

.mobile-nav a.active,
.mobile-nav a:active {
    color: #ffffff;
    background: var(--primary);
    box-shadow: 0 8px 18px rgba(70, 139, 223, .24);
}

main {
    max-width: 720px;
    margin: 0 auto;
    padding: 18px 14px 36px;
}

.banner,
.page-hero {
    position: relative;
    overflow: hidden;
    border-radius: 30px;
    padding: 28px 20px;
    background:
        linear-gradient(135deg, rgba(70, 139, 223, .14), rgba(255,255,255,.92) 54%),
        linear-gradient(180deg, #ffffff, #f4faff);
    box-shadow: var(--shadow);
    border: 1px solid rgba(70, 139, 223, .16);
}

.banner::after,
.page-hero::after {
    content: "";
    position: absolute;
    width: 150px;
    height: 150px;
    border-radius: 50%;
    right: -64px;
    top: -44px;
    background: rgba(70, 139, 223, .16);
}

.hero-text,
.page-hero > * {
    position: relative;
    z-index: 1;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    margin: 0 0 10px;
    padding: 6px 10px;
    border-radius: 999px;
    color: var(--primary-dark);
    background: rgba(70, 139, 223, .11);
    font-size: 12px;
    font-weight: 800;
}

h1,
h2,
h3 {
    margin: 0;
    line-height: 1.25;
    letter-spacing: -.035em;
}

h1 {
    font-size: clamp(28px, 7vw, 42px);
    color: #102342;
}

h2 {
    font-size: 23px;
    color: #142a4a;
}

h3 {
    font-size: 17px;
    color: #17365f;
}

.lead {
    margin: 14px 0 0;
    color: #50647f;
    font-size: 16px;
}

.hero-actions {
    margin-top: 22px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 52px;
    border-radius: 18px;
    background: var(--primary);
    color: #ffffff;
    border: 0;
    font-weight: 800;
    font-size: 16px;
    box-shadow: 0 14px 30px rgba(70, 139, 223, .28);
    transition: transform .18s ease, box-shadow .18s ease;
}

.download-btn:active {
    transform: translateY(1px) scale(.99);
    box-shadow: 0 10px 20px rgba(70, 139, 223, .24);
}

.trust-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 16px;
}

.trust-tags span,
.badge {
    display: inline-flex;
    align-items: center;
    min-height: 30px;
    padding: 6px 10px;
    border-radius: 999px;
    color: #245fba;
    background: rgba(70, 139, 223, .10);
    border: 1px solid rgba(70, 139, 223, .12);
    font-size: 12px;
    font-weight: 800;
}

.hero-device {
    margin-top: 24px;
    border-radius: 28px;
    padding: 18px;
    background: linear-gradient(180deg, #ffffff, #edf6ff);
    box-shadow: inset 0 0 0 1px rgba(70, 139, 223, .12), 0 18px 36px rgba(31, 77, 146, .10);
}

.hero-device img {
    width: min(260px, 80%);
    margin: 0 auto;
    filter: drop-shadow(0 24px 34px rgba(41, 83, 140, .18));
}

.device-panel {
    margin-top: 12px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.data-block {
    padding: 12px;
    background: rgba(255,255,255,.88);
    border: 1px solid rgba(70,139,223,.12);
    border-radius: 18px;
}

.data-block strong {
    display: block;
    font-size: 19px;
    color: var(--primary-dark);
}

.data-block span {
    display: block;
    margin-top: 2px;
    color: var(--muted);
    font-size: 12px;
}

.section {
    margin-top: 22px;
}

.section-title {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 13px;
}

.section-title p {
    margin: 0;
    color: var(--muted);
    font-size: 13px;
}

.card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 18px;
    box-shadow: var(--shadow);
}

.card + .card {
    margin-top: 12px;
}

.card p {
    margin: 10px 0 0;
    color: #53677f;
}

.card ul,
.card ol {
    margin: 12px 0 0;
    padding-left: 20px;
    color: #52657d;
}

.card li + li {
    margin-top: 8px;
}

.soft-card {
    background: linear-gradient(135deg, #f8fbff, #eef6ff);
}

.feature-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

.feature-card {
    padding: 18px;
    border-radius: var(--radius-md);
    background: rgba(255,255,255,.9);
    border: 1px solid rgba(70,139,223,.13);
    box-shadow: 0 10px 26px rgba(33, 80, 150, .07);
}

.icon-dot {
    width: 34px;
    height: 34px;
    display: grid;
    place-items: center;
    border-radius: 12px;
    color: #fff;
    background: var(--primary);
    box-shadow: 0 8px 18px rgba(70,139,223,.24);
    font-weight: 900;
}

.feature-card h3 {
    margin-top: 12px;
}

.feature-card p {
    margin: 8px 0 0;
    color: #5b6f88;
    font-size: 14px;
}

.split-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

.step-list {
    counter-reset: step;
    display: grid;
    gap: 12px;
}

.step-item {
    position: relative;
    padding: 16px 16px 16px 58px;
    border-radius: 20px;
    background: #fff;
    border: 1px solid rgba(70,139,223,.13);
}

.step-item::before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 16px;
    top: 16px;
    width: 30px;
    height: 30px;
    display: grid;
    place-items: center;
    border-radius: 12px;
    background: var(--primary);
    color: #fff;
    font-weight: 900;
}

.faq-item {
    border-radius: 18px;
    background: #ffffff;
    border: 1px solid rgba(70,139,223,.14);
    padding: 16px;
}

.faq-item + .faq-item {
    margin-top: 10px;
}

.faq-item h3 {
    font-size: 16px;
}

.faq-item p {
    margin: 8px 0 0;
    color: #53677f;
    font-size: 14px;
}

.note-box {
    border-radius: 20px;
    padding: 16px;
    background: rgba(70,139,223,.09);
    border: 1px solid rgba(70,139,223,.16);
    color: #2d517d;
}

.note-box strong {
    display: block;
    color: #17365f;
    margin-bottom: 6px;
}

.cta-panel {
    margin-top: 22px;
    padding: 20px;
    border-radius: 26px;
    background: linear-gradient(135deg, rgba(70,139,223,.16), #ffffff 58%);
    border: 1px solid rgba(70,139,223,.16);
    box-shadow: var(--shadow);
}

.cta-panel p {
    color: #5b6f88;
    margin: 10px 0 16px;
}

.article-body p {
    margin: 12px 0 0;
    color: #53677f;
}

.article-body .download-btn {
    margin-top: 18px;
}

.site-footer {
    max-width: 720px;
    margin: 0 auto;
    padding: 8px 14px 28px;
}

.footer-card {
    padding: 18px;
    border-radius: 26px;
    background: rgba(255,255,255,.86);
    border: 1px solid rgba(70,139,223,.13);
    box-shadow: var(--shadow);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-brand img {
    width: 38px;
    height: 38px;
    border-radius: 13px;
}

.footer-brand p,
.footer-note,
.copyright {
    margin: 2px 0 0;
    color: #64748b;
    font-size: 13px;
}

.footer-links {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin-top: 16px;
}

.footer-links a {
    padding: 10px;
    border-radius: 14px;
    background: rgba(70,139,223,.08);
    color: #245fba;
    font-size: 13px;
    font-weight: 700;
}

.footer-note {
    margin-top: 16px;
}

.copyright {
    margin-top: 10px;
}

.desktop-guard {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: none;
    place-items: center;
    padding: 24px;
    background: linear-gradient(180deg, rgba(243,249,255,.97), rgba(255,255,255,.97));
}

.desktop-guard-card {
    width: min(440px, 92vw);
    padding: 34px;
    border-radius: 28px;
    text-align: center;
    background: #ffffff;
    border: 1px solid rgba(70,139,223,.16);
    box-shadow: 0 24px 60px rgba(25, 66, 132, .14);
}

.desktop-guard-logo {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    border-radius: 20px;
}

.desktop-guard-card h2 {
    margin: 0;
    font-size: 30px;
    line-height: 1.25;
    letter-spacing: -.035em;
    color: #102342;
}

.desktop-mode .desktop-guard {
    display: grid;
}

.desktop-guard-card p {
    color: #5c7089;
}

.desktop-mode .download-btn {
    display: none;
}

@media (min-width: 560px) {
    .header-inner {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }

    .mobile-nav {
        min-width: 300px;
    }

    .banner {
        display: grid;
        grid-template-columns: 1.05fr .95fr;
        gap: 20px;
        align-items: center;
    }

    .hero-device {
        margin-top: 0;
    }

    .feature-grid,
    .split-grid {
        grid-template-columns: 1fr 1fr;
    }
}