:root {
    --primary: #00a8ff;
    --primary-dark: #087db8;
    --ink: #243447;
    --muted: #667085;
    --line: #dfe5ec;
    --surface: #f5f7fa;
    --success: #208a55;
}
* { box-sizing: border-box; }
body { margin: 0; color: var(--ink); background: var(--surface); font-family: "Helvetica Neue", Arial, "Segoe UI", sans-serif; line-height: 1.8; }
a { color: var(--primary-dark); }
.site-header { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 14px max(24px, calc((100vw - 1080px) / 2)); background: #fff; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 800; text-decoration: none; }
.brand img { width: 30px; height: 30px; }
.header-cta, .primary-cta { display: inline-flex; align-items: center; justify-content: center; border-radius: 9px; background: linear-gradient(135deg, #00a8ff, #008bd4); color: #fff; font-weight: 800; text-decoration: none; box-shadow: 0 7px 18px rgba(0, 139, 212, .2); }
.header-cta { padding: 8px 14px; font-size: 13px; }
.primary-cta { padding: 13px 22px; }
.hero { padding: 72px 24px 58px; background: radial-gradient(circle at 85% 20%, #dff4ff 0, transparent 30%), #fff; border-bottom: 1px solid var(--line); }
.hero-inner, .content, .related { width: min(920px, 100%); margin: 0 auto; }
.eyebrow { color: var(--primary-dark); font-size: 12px; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
h1 { margin: 8px 0 18px; font-size: clamp(30px, 5vw, 48px); line-height: 1.28; letter-spacing: -.02em; }
.lead { max-width: 720px; margin: 0 0 28px; color: var(--muted); font-size: 17px; }
.trust-line { margin-top: 18px; color: var(--success); font-size: 13px; font-weight: 700; }
.content { padding: 56px 24px; }
.content section { margin-bottom: 52px; }
h2 { margin: 0 0 18px; font-size: 26px; line-height: 1.4; }
h3 { margin: 0 0 8px; font-size: 17px; }
.feature-grid, .steps, .use-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card, .step { padding: 22px; background: #fff; border: 1px solid var(--line); border-radius: 13px; box-shadow: 0 8px 24px rgba(31,45,61,.05); }
.card p, .step p { margin: 0; color: var(--muted); font-size: 14px; }
.step-number { display: inline-grid; place-items: center; width: 28px; height: 28px; margin-bottom: 12px; border-radius: 50%; background: #e1f4ff; color: var(--primary-dark); font-size: 13px; font-weight: 800; }
.notice { padding: 22px 24px; border-left: 4px solid var(--primary); border-radius: 8px; background: #edf8ff; }
.notice strong { display: block; margin-bottom: 5px; }
.operation-demo { margin: 24px 0 0; }
.operation-demo img, .operation-demo video { display: block; width: 100%; height: auto; max-height: 680px; object-fit: contain; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.operation-demo figcaption { margin-top: 9px; color: var(--muted); font-size: 12px; text-align: center; }
.faq details { margin-bottom: 10px; padding: 16px 18px; background: #fff; border: 1px solid var(--line); border-radius: 9px; }
.faq summary { cursor: pointer; font-weight: 700; }
.faq p { margin: 10px 0 0; color: var(--muted); }
.bottom-cta { padding: 34px; border-radius: 16px; background: #243447; color: #fff; text-align: center; }
.bottom-cta h2 { margin-bottom: 10px; }
.bottom-cta p { margin: 0 0 20px; color: #dbe3ec; }
.related { padding: 0 24px 54px; }
.related-links { display: flex; flex-wrap: wrap; gap: 10px; }
.related-links a { padding: 7px 12px; border: 1px solid var(--line); border-radius: 999px; background: #fff; font-size: 13px; text-decoration: none; }
.site-footer { padding: 24px; background: #e9edf2; color: var(--muted); font-size: 12px; text-align: center; }
.site-footer a { margin: 0 7px; color: #526477; }
@media (max-width: 720px) {
    .site-header { padding: 12px 16px; }
    .hero { padding: 52px 20px 42px; }
    .content { padding: 42px 18px; }
    .feature-grid, .steps, .use-grid { grid-template-columns: 1fr; }
    .header-cta { display: none; }
    .bottom-cta { padding: 28px 20px; }
}