:root {
    --primary: rgb(70,139,223);
    --primary-deep: #1f5ea8;
    --primary-soft: #eaf4ff;
    --ink: #102033;
    --muted: #607086;
    --line: #dbe8f7;
    --card: #ffffff;
    --bg: #f6fbff;
    --shadow: 0 18px 45px rgba(31, 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: linear-gradient(180deg, #eef7ff 0%, #ffffff 36%, #f6fbff 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, 0.9);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(219, 232, 247, 0.85);
}

.nav-wrap {
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.brand,
.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #123456;
    letter-spacing: 0.02em;
}

.logo,
.footer-brand img {
    width: 38px;
    height: 38px;
    object-fit: contain;
}

.nav-toggle {
    width: 42px;
    height: 42px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: #fff;
    color: var(--primary-deep);
    font-size: 22px;
}

.site-nav {
    display: none;
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #fff;
    box-shadow: var(--shadow);
}

.site-nav.open {
    display: grid;
    gap: 6px;
}

.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #31455d;
    font-weight: 600;
}

.site-nav a.active,
.site-nav a:hover {
    background: var(--primary-soft);
    color: var(--primary-deep);
}

section,
.page-section {
    padding: 54px 0;
}

.hero {
    position: relative;
    padding: 46px 0 36px;
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    inset: -120px -160px auto auto;
    width: 380px;
    height: 380px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(70,139,223,0.25), rgba(70,139,223,0));
    pointer-events: none;
}

.hero-layout,
.security-layout,
.split-layout,
.guide-layout {
    display: grid;
    gap: 28px;
    align-items: center;
}

.eyebrow,
.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    background: rgba(70,139,223,0.1);
    color: var(--primary-deep);
    font-size: 13px;
    font-weight: 700;
}

h1,
h2,
h3 {
    line-height: 1.25;
    color: #102033;
    margin: 0 0 14px;
}

h1 {
    font-size: clamp(30px, 8vw, 56px);
    letter-spacing: -0.04em;
}

h2 {
    font-size: clamp(24px, 5vw, 36px);
    letter-spacing: -0.025em;
}

h3 {
    font-size: 19px;
}

p {
    margin: 0 0 14px;
    color: var(--muted);
}

.hero-copy p,
.section-lead {
    font-size: 16px;
    max-width: 760px;
}

.hero-actions {
    margin-top: 26px;
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    align-items: center;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    background: rgb(70,139,223);
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 28px rgba(70,139,223,0.28);
    border: 0;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 18px 34px rgba(70,139,223,0.34);
}

.text-link {
    color: var(--primary-deep);
    font-weight: 800;
}

.hero-tags,
.tag-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 20px;
}

.hero-tags span,
.tag-row span,
.mini-tag {
    padding: 8px 11px;
    border-radius: 999px;
    background: #fff;
    border: 1px solid var(--line);
    color: #35506c;
    font-size: 13px;
    font-weight: 650;
}

.product-visual {
    position: relative;
    min-height: 420px;
    padding: 22px;
    border-radius: 32px;
    background: linear-gradient(145deg, rgba(255,255,255,0.9), rgba(234,244,255,0.8));
    border: 1px solid rgba(219,232,247,0.9);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.product-visual::after {
    content: "";
    position: absolute;
    right: -80px;
    bottom: -80px;
    width: 220px;
    height: 220px;
    border-radius: 50%;
    background: rgba(70,139,223,0.12);
}

.app-img {
    width: min(76%, 280px);
    margin: 0 auto;
    filter: drop-shadow(0 24px 30px rgba(31,94,168,0.18));
}

.status-card,
.float-card {
    position: absolute;
    z-index: 2;
    background: rgba(255,255,255,0.92);
    border: 1px solid rgba(219,232,247,0.95);
    box-shadow: 0 12px 32px rgba(31,94,168,0.12);
    border-radius: 18px;
    padding: 14px;
}

.status-card {
    left: 18px;
    bottom: 22px;
    width: 190px;
}

.status-dot {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    display: inline-block;
    background: #3fc879;
    margin-right: 7px;
}

.float-card {
    right: 18px;
    top: 44px;
    width: 150px;
}

.float-card strong,
.status-card strong {
    display: block;
    color: #14283e;
}

.float-card small,
.status-card small {
    color: var(--muted);
}

.trust-grid,
.category-grid,
.feature-grid,
.scenario-grid,
.faq-grid,
.card-grid,
.page-grid {
    display: grid;
    gap: 18px;
}

.trust-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.trust-item,
.category-card,
.feature-card,
.scenario-card,
.faq-item,
.info-card,
.step,
.note-card,
.page-card {
    background: rgba(255,255,255,0.92);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: 0 10px 24px rgba(31,94,168,0.07);
}

.trust-item strong {
    display: block;
    font-size: 18px;
    margin-bottom: 4px;
}

.category-card {
    position: relative;
    overflow: hidden;
}

.category-card::after {
    content: "";
    position: absolute;
    right: -34px;
    top: -34px;
    width: 90px;
    height: 90px;
    border-radius: 50%;
    background: rgba(70,139,223,0.1);
}

.category-card a,
.card-link {
    display: inline-flex;
    margin-top: 10px;
    color: var(--primary-deep);
    font-weight: 800;
}

.feature-icon {
    width: 46px;
    height: 46px;
    border-radius: 16px;
    display: grid;
    place-items: center;
    background: var(--primary-soft);
    color: var(--primary-deep);
    font-weight: 900;
    margin-bottom: 14px;
}

.security-panel {
    border-radius: 28px;
    padding: 24px;
    background: linear-gradient(145deg, #ffffff, #eef7ff);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.security-row {
    display: flex;
    justify-content: space-between;
    gap: 14px;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
}

.security-row:last-child {
    border-bottom: 0;
}

.security-row span {
    color: var(--muted);
}

.security-row strong {
    color: var(--primary-deep);
}

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

.step {
    position: relative;
    padding-left: 64px;
}

.step::before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 20px;
    top: 22px;
    width: 30px;
    height: 30px;
    border-radius: 12px;
    display: grid;
    place-items: center;
    background: var(--primary);
    color: #fff;
    font-weight: 900;
}

.cta-section {
    text-align: center;
    padding: 44px 22px;
    border-radius: 32px;
    background: linear-gradient(135deg, rgba(70,139,223,0.13), rgba(255,255,255,0.92));
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.cta-section .download-btn {
    margin-top: 14px;
}

.page-hero {
    padding: 48px 0 24px;
}

.page-hero .container {
    padding: 28px;
    border-radius: 30px;
    background: linear-gradient(135deg, rgba(255,255,255,0.96), rgba(234,244,255,0.9));
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.prose-block {
    max-width: 820px;
}

.prose-block p {
    font-size: 16px;
}

.tip-list,
.clean-list {
    list-style: none;
    padding: 0;
    margin: 14px 0 0;
    display: grid;
    gap: 10px;
}

.tip-list li,
.clean-list li {
    position: relative;
    padding-left: 26px;
    color: var(--muted);
}

.tip-list li::before,
.clean-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.72em;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--primary);
}

.faq-item h3 {
    margin-bottom: 8px;
}

.download-panel {
    max-width: 740px;
    margin: 0 auto;
    text-align: center;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 30px;
    box-shadow: var(--shadow);
}

.download-panel .download-btn {
    margin: 18px auto 0;
}

.site-footer {
    margin-top: 40px;
    padding: 46px 0 22px;
    background: #f0f7ff;
    border-top: 1px solid var(--line);
}

.footer-grid {
    display: grid;
    gap: 24px;
}

.footer-grid h3 {
    font-size: 15px;
    margin-bottom: 10px;
}

.footer-grid a {
    display: block;
    color: #53677d;
    margin: 7px 0;
}

.footer-grid a:hover {
    color: var(--primary-deep);
}

.footer-bottom {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding-top: 22px;
    margin-top: 20px;
    border-top: 1px solid var(--line);
    color: #6a7b8f;
    font-size: 13px;
}

@media (min-width: 640px) {
    .category-grid,
    .feature-grid,
    .scenario-grid,
    .card-grid,
    .page-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 860px) {
    .nav-toggle {
        display: none;
    }

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

    .site-nav a {
        padding: 9px 12px;
        font-size: 14px;
    }

    .hero {
        padding: 74px 0 48px;
    }

    .hero-layout,
    .security-layout,
    .split-layout,
    .guide-layout {
        grid-template-columns: 1.05fr 0.95fr;
        gap: 46px;
    }

    .category-grid,
    .feature-grid,
    .scenario-grid,
    .page-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .trust-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .steps {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .step {
        padding: 58px 20px 20px;
    }

    .step::before {
        left: 20px;
        top: 20px;
    }

    .faq-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .footer-grid {
        grid-template-columns: 1.4fr 1fr 1fr 1fr;
    }

    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
    }
}

@media (min-width: 1080px) {
    .container {
        width: min(100% - 48px, 1160px);
    }

    .product-visual {
        min-height: 520px;
    }

    .app-img {
        width: 310px;
    }
}