:root {
    color-scheme: light;
    --page-bg: #f6f8fb;
    --surface: #ffffff;
    --surface-soft: #eef5ff;
    --ink: #172033;
    --muted: #5d687a;
    --line: #dbe3ef;
    --accent: #1d64d8;
    --accent-strong: #164aa3;
    --success: #0f8a5f;
    --shadow: 0 18px 50px rgba(20, 38, 75, 0.12);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--page-bg);
    color: var(--ink);
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.65;
}

a {
    color: inherit;
}

.site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    max-width: 1120px;
    margin: 0 auto;
    padding: 22px 22px 8px;
}

.brand,
.top-nav {
    display: flex;
    align-items: center;
}

.brand {
    gap: 10px;
    color: var(--ink);
    font-weight: 800;
    text-decoration: none;
}

.brand-mark {
    display: grid;
    width: 34px;
    height: 34px;
    place-items: center;
    border-radius: 8px;
    background: var(--accent);
    color: #fff;
}

.top-nav {
    gap: 10px;
    flex-wrap: wrap;
}

.top-nav a {
    padding: 8px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface);
    color: var(--muted);
    font-size: 14px;
    text-decoration: none;
}

.top-nav a:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.guide-shell {
    max-width: 1120px;
    margin: 0 auto;
    padding: 20px 22px 64px;
}

.hero {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 310px;
    gap: 34px;
    align-items: center;
    min-height: 430px;
    padding: 42px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface);
    box-shadow: var(--shadow);
}

.eyebrow {
    margin: 0 0 12px;
    color: var(--accent);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 0;
    text-transform: uppercase;
}

h1,
h2,
h3,
p {
    overflow-wrap: anywhere;
}

h1 {
    max-width: 760px;
    margin: 0;
    font-size: 40px;
    line-height: 1.18;
}

.lead {
    max-width: 720px;
    margin: 22px 0 0;
    color: var(--muted);
    font-size: 18px;
}

.qr-visual {
    display: grid;
    justify-items: center;
    gap: 16px;
    padding: 26px;
    border-radius: 8px;
    background: var(--surface-soft);
    border: 1px solid #d5e6ff;
}

.qr-frame {
    position: relative;
    display: grid;
    grid-template-columns: repeat(4, 44px);
    grid-template-rows: repeat(4, 44px);
    gap: 8px;
    padding: 16px;
    border: 10px solid #fff;
    border-radius: 8px;
    background: #fff;
    box-shadow: 0 16px 34px rgba(29, 100, 216, 0.18);
}

.qr-frame span,
.qr-frame i {
    display: block;
    border-radius: 6px;
}

.qr-frame span {
    background: var(--accent);
}

.qr-frame i {
    background: #13213a;
}

.qr-frame i:nth-of-type(2),
.qr-frame i:nth-of-type(5),
.qr-frame i:nth-of-type(7) {
    background: var(--success);
}

.qr-visual p {
    margin: 0;
    color: var(--accent-strong);
    font-weight: 700;
    text-align: center;
}

.content-section {
    margin-top: 24px;
    padding: 34px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface);
}

.content-section h2 {
    margin: 0 0 16px;
    font-size: 28px;
    line-height: 1.28;
}

.content-section h3 {
    margin: 0 0 8px;
    font-size: 19px;
    line-height: 1.35;
}

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

.content-section p:last-child {
    margin-bottom: 0;
}

.intro {
    font-size: 17px;
}

.video-frame {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 0;
    padding-top: 56.25%;
    margin-top: 18px;
    border: 1px solid #101827;
    border-radius: 8px;
    background: #050506;
    box-shadow: 0 18px 38px rgba(13, 24, 38, 0.16);
}

.video-frame iframe {
    position: absolute;
    inset: 0;
    display: block;
    width: 100%;
    height: 100%;
    border: 0;
}

.requirement-grid,
.benefit-list {
    display: grid;
    gap: 16px;
}

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

.requirement-item,
.benefit-list > div {
    min-width: 0;
    padding: 20px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fbfdff;
}

.steps {
    display: grid;
    gap: 16px;
    margin: 0;
    padding: 0;
    list-style: none;
    counter-reset: qr-step;
}

.steps li {
    position: relative;
    padding: 22px 22px 22px 72px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fbfdff;
    counter-increment: qr-step;
}

.steps li::before {
    content: counter(qr-step);
    position: absolute;
    top: 22px;
    left: 22px;
    display: grid;
    width: 34px;
    height: 34px;
    place-items: center;
    border-radius: 8px;
    background: var(--accent);
    color: #fff;
    font-weight: 800;
}

.step-figure {
    margin: 20px 0 0;
}

.step-figure + .step-figure {
    margin-top: 18px;
}

.steps .step-figure + p {
    margin-top: 24px;
}

.step-figure figcaption {
    margin: 0 0 10px;
    color: var(--ink);
    font-size: 14px;
    font-weight: 800;
}

.guide-screenshot {
    max-width: 960px;
}

.phone-screenshot {
    max-width: 300px;
}

.guide-screenshot picture {
    display: block;
    overflow: hidden;
    border: 1px solid #d8dee8;
    border-radius: 8px;
    background: #050506;
    box-shadow: 0 18px 38px rgba(13, 24, 38, 0.16);
}

.guide-screenshot img {
    display: block;
    width: 100%;
    height: auto;
}

.phone-screenshot picture {
    background: #000;
}

.benefit-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.notice {
    border-color: #bfe5d6;
    background: #f1fbf7;
}

.notice h2 {
    color: var(--success);
}

@media (max-width: 860px) {
    .site-header {
        align-items: flex-start;
        flex-direction: column;
    }

    .hero {
        grid-template-columns: 1fr;
        min-height: auto;
        padding: 28px;
    }

    h1 {
        font-size: 31px;
    }

    .lead {
        font-size: 16px;
    }

    .qr-visual {
        justify-self: stretch;
    }

    .requirement-grid,
    .benefit-list {
        grid-template-columns: 1fr;
    }

}

@media (max-width: 520px) {
    .site-header,
    .guide-shell {
        padding-left: 14px;
        padding-right: 14px;
    }

    .hero,
    .content-section {
        padding: 22px;
    }

    h1 {
        font-size: 27px;
    }

    .content-section h2 {
        font-size: 24px;
    }

    .qr-frame {
        grid-template-columns: repeat(4, 34px);
        grid-template-rows: repeat(4, 34px);
        gap: 7px;
    }

    .steps li {
        padding: 70px 18px 18px;
    }

    .steps li::before {
        top: 20px;
        left: 18px;
    }

}