*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root { --blue: #0052cc; --blue-dark: #0747a6; --ink: #172b4d; --muted: #42526e; --soft: #f7f8fa; --line: #dfe1e6; --amber: #946200; }
body { font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: var(--ink); background: #fff; line-height: 1.7; }
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
.top-nav { background: var(--blue); padding: 16px 40px; display: flex; align-items: center; gap: 20px; }
.brand { color: #fff; font-weight: 700; font-size: 20px; }
.nav-links { margin-left: auto; display: flex; align-items: center; gap: 22px; }
.nav-links a { color: rgba(255,255,255,0.86); font-size: 14px; font-weight: 600; }
.nav-links a:hover { color: #fff; text-decoration: none; }
.hero { background: linear-gradient(135deg, var(--blue) 0%, var(--blue-dark) 100%); color: #fff; padding: 72px 24px 64px; }
.hero-inner, .container, .article-shell { max-width: 1080px; margin: 0 auto; }
.eyebrow { color: rgba(255,255,255,0.72); font-size: 13px; font-weight: 700; letter-spacing: 0.08em; margin-bottom: 14px; text-transform: uppercase; }
.hero h1 { font-size: 44px; line-height: 1.13; max-width: 780px; margin-bottom: 18px; }
.hero p { color: rgba(255,255,255,0.86); font-size: 19px; max-width: 720px; }
.container { padding: 54px 24px 88px; }
.section-heading { margin-bottom: 28px; }
.section-heading h2 { font-size: 28px; margin-bottom: 8px; }
.section-heading p { color: var(--muted); max-width: 680px; }
.topic-strip { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0 8px; }
.topic-chip { border: 1px solid rgba(255,255,255,0.28); border-radius: 999px; color: #fff; font-size: 13px; padding: 6px 12px; }
.guide-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.guide-card { border: 1px solid var(--line); border-radius: 8px; padding: 22px; background: #fff; min-height: 220px; display: flex; flex-direction: column; }
.guide-card:hover { border-color: var(--blue); box-shadow: 0 10px 24px rgba(9,30,66,0.08); text-decoration: none; }
.guide-kicker { color: var(--blue); font-size: 12px; font-weight: 700; letter-spacing: 0.06em; margin-bottom: 10px; text-transform: uppercase; }
.guide-card h3 { color: var(--ink); font-size: 18px; line-height: 1.35; margin-bottom: 10px; }
.guide-card p { color: var(--muted); font-size: 14px; }
.guide-meta { color: #6b778c; font-size: 12px; margin-top: auto; padding-top: 18px; }
.feature-band { background: var(--soft); border: 1px solid #ebecf0; border-radius: 8px; display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 24px; margin: 46px 0; padding: 28px; }
.feature-band h2 { font-size: 24px; margin-bottom: 10px; }
.feature-band p { color: var(--muted); }
.btn { background: var(--blue); border-radius: 6px; color: #fff; display: inline-block; font-weight: 700; margin-top: 18px; padding: 10px 16px; }
.btn:hover { background: var(--blue-dark); text-decoration: none; }
.article-hero { background: #f0f4ff; border-bottom: 1px solid #dfe7ff; padding: 54px 24px 44px; }
.article-hero-inner { max-width: 920px; margin: 0 auto; }
.article-hero .eyebrow { color: var(--blue); }
.article-hero h1 { font-size: 40px; line-height: 1.16; max-width: 840px; margin-bottom: 16px; }
.article-summary { color: var(--muted); font-size: 19px; max-width: 780px; }
.article-meta { color: #6b778c; font-size: 13px; margin-top: 18px; }
.article-shell { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 46px; padding: 46px 24px 88px; }
.article-body { max-width: 720px; }
.article-body h2 { font-size: 25px; line-height: 1.3; margin: 34px 0 12px; }
.article-body h3 { font-size: 19px; margin: 26px 0 10px; }
.article-body p { color: var(--muted); margin-bottom: 16px; }
.article-body ul, .article-body ol { color: var(--muted); margin: 0 0 18px 24px; }
.article-body li { margin-bottom: 8px; }
.article-body strong { color: var(--ink); }
.article-body code { background: #f4f5f7; border-radius: 4px; color: #253858; font-family: "SFMono-Regular", Consolas, monospace; font-size: 0.94em; padding: 2px 5px; }
.note, .warning, .cta-card { border-radius: 8px; margin: 24px 0; padding: 18px 20px; }
.note { background: #f4f5f7; border-left: 4px solid var(--blue); }
.warning { background: #fff7e6; border-left: 4px solid var(--amber); }
.cta-card { background: #f0f4ff; border: 1px solid #dfe7ff; }
.cta-card h2, .cta-card h3 { margin-top: 0; }
.cta-card p:last-child, .note p:last-child, .warning p:last-child { margin-bottom: 0; }
.article-aside { align-self: start; position: sticky; top: 20px; }
.aside-card { border: 1px solid var(--line); border-radius: 8px; margin-bottom: 18px; padding: 18px; }
.aside-card h2 { font-size: 15px; margin-bottom: 10px; }
.aside-card a { display: block; font-size: 14px; margin: 8px 0; }
.aside-card p { color: var(--muted); font-size: 14px; }
.checklist { display: grid; gap: 12px; margin: 22px 0; }
.check-item { border: 1px solid var(--line); border-radius: 8px; padding: 14px 16px; }
.check-item label { color: var(--ink); cursor: pointer; display: flex; gap: 10px; font-weight: 600; }
.check-item input { margin-top: 5px; width: 16px; height: 16px; flex-shrink: 0; }
.check-item p { font-size: 14px; margin: 8px 0 0 26px; }
.footer { border-top: 1px solid #ebecf0; color: #6b778c; font-size: 13px; padding: 32px 24px; text-align: center; }
.footer a { margin: 0 8px; }
@media (max-width: 860px) { .guide-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } .feature-band { grid-template-columns: 1fr; } .article-shell { grid-template-columns: 1fr; } .article-aside { position: static; } }
@media (max-width: 620px) { .top-nav { align-items: flex-start; flex-direction: column; padding: 16px 24px; } .nav-links { flex-wrap: wrap; gap: 14px; margin-left: 0; } .hero h1, .article-hero h1 { font-size: 31px; } .guide-grid { grid-template-columns: 1fr; } }