*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #FFFFFF;
  --bg-soft: #F5F7FB;
  --bg-2: #ECF0F8;
  --ink: #141A2E;
  --ink-2: #2B344C;
  --text: #404A63;
  --slate: #69748F;
  --muted: #9AA3B8;
  --line: #E4E9F2;
  --line-2: #D2DAE8;
  --paper: #FFFFFF;
  --brand: #2D6BF0;
  --brand-deep: #1E50C4;
  --brand-soft: #EAF1FE;
  --green: #1AA463;
  --amber: #E8920C;
  --red: #E0564E;
  --radius: 14px;
  --radius-sm: 9px;
  --maxw: 1080px;
  --read: 760px;
  --fd: 'Space Grotesk', system-ui, sans-serif;
  --fb: 'Inter', system-ui, -apple-system, sans-serif;
  --fm: 'JetBrains Mono', ui-monospace, monospace;
}

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { font-family: var(--fb); background: var(--bg); color: var(--text); line-height: 1.75; font-size: 16.5px; -webkit-font-smoothing: antialiased; }
img, svg { display: block; max-width: 100%; }
a { color: var(--brand-deep); }
ul { list-style: none; }
code { font-family: var(--fm); }

.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { left: 8px; top: 8px; background: var(--brand); color: #fff; padding: 8px 14px; border-radius: 8px; z-index: 200; }

.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: 22px; }
.read { max-width: var(--read); margin-inline: auto; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.9); backdrop-filter: blur(14px); border-bottom: 1px solid var(--line); }
.header-bar { display: flex; align-items: center; justify-content: space-between; gap: 18px; min-height: 60px; }
.brand { display: flex; align-items: center; gap: 9px; font-family: var(--fd); font-weight: 700; font-size: 19px; color: var(--ink); text-decoration: none; letter-spacing: -0.01em; }
.brand-mark { width: 30px; height: 30px; border-radius: 8px; background: linear-gradient(135deg, var(--brand), #5B8DEF); display: grid; place-items: center; }
.brand-mark svg { width: 17px; height: 17px; }
.brand .accent { color: var(--brand); }
.nav-inline { display: flex; gap: 6px; }
.nav-inline a { color: var(--slate); font-size: 14px; font-weight: 500; padding: 8px 12px; border-radius: 7px; text-decoration: none; }
.nav-inline a:hover { color: var(--ink); background: var(--bg-soft); }
@media (max-width: 640px) { .nav-inline { display: none; } }

/* Article header */
.art-hero { padding-block: 46px 30px; border-bottom: 1px solid var(--line); background: linear-gradient(180deg, var(--brand-soft), transparent); }
.crumb { font-size: 13px; color: var(--muted); margin-bottom: 16px; }
.crumb a { color: var(--brand-deep); text-decoration: none; }
.art-cat { display: inline-block; font-family: var(--fm); font-size: 12px; color: var(--brand-deep); background: var(--brand-soft); border: 1px solid var(--line-2); padding: 5px 11px; border-radius: 6px; margin-bottom: 16px; }
.art-hero h1 { font-family: var(--fd); font-size: clamp(28px, 4.6vw, 42px); font-weight: 700; line-height: 1.15; letter-spacing: -0.02em; color: var(--ink); }
.art-meta { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-top: 18px; font-size: 13.5px; color: var(--muted); }

/* Article body */
.article { padding-block: 40px 60px; }
.toc { background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; margin-bottom: 36px; }
.toc h2 { font-family: var(--fd); font-size: 14px; text-transform: uppercase; letter-spacing: .05em; color: var(--slate); margin-bottom: 12px; }
.toc ol { list-style: none; counter-reset: t; display: grid; gap: 8px; }
.toc li { counter-increment: t; }
.toc a { color: var(--ink-2); font-size: 14.5px; text-decoration: none; }
.toc a::before { content: counter(t, decimal-leading-zero) " · "; color: var(--brand); font-family: var(--fm); font-size: 12px; }
.toc a:hover { color: var(--brand-deep); }

.article p { font-size: 16.5px; color: var(--text); margin-bottom: 18px; }
.article h2 { font-family: var(--fd); font-size: clamp(23px, 3.4vw, 30px); font-weight: 700; color: var(--ink); margin: 44px 0 14px; letter-spacing: -0.01em; line-height: 1.2; }
.article h3 { font-family: var(--fd); font-size: 19px; font-weight: 600; color: var(--ink); margin: 26px 0 8px; }
.article strong { color: var(--ink); }
.article a { color: var(--brand-deep); }
.lead { font-size: 19px; color: var(--slate); line-height: 1.7; margin-bottom: 8px; }

.answer { background: var(--brand-soft); border: 1px solid var(--line-2); border-left: 4px solid var(--brand); border-radius: 12px; padding: 20px 24px; margin: 26px 0; }
.answer p { margin: 0; font-size: 16px; }
.answer strong { color: var(--ink); }

/* steps */
.steps { counter-reset: s; display: flex; flex-direction: column; gap: 14px; margin: 22px 0; }
.step { display: flex; gap: 16px; align-items: flex-start; background: var(--paper); border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; }
.step .num { counter-increment: s; flex-shrink: 0; width: 30px; height: 30px; border-radius: 8px; background: var(--brand); color: #fff; font-family: var(--fd); font-weight: 700; display: grid; place-items: center; font-size: 14px; }
.step .num::before { content: counter(s); }
.step .sc h3 { margin: 0 0 4px; font-size: 16.5px; }
.step .sc p { margin: 0; font-size: 14.5px; color: var(--slate); }

/* pros cons */
.pc-grid { display: grid; grid-template-columns: 1fr; gap: 16px; margin: 22px 0; }
@media (min-width: 640px) { .pc-grid { grid-template-columns: 1fr 1fr; } }
.pc { border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; }
.pc.pros { background: rgba(26,164,99,.05); border-color: rgba(26,164,99,.25); }
.pc.cons { background: rgba(224,86,78,.05); border-color: rgba(224,86,78,.25); }
.pc h3 { font-family: var(--fd); font-size: 17px; margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.pc.pros h3 { color: var(--green); }
.pc.cons h3 { color: var(--red); }
.pc li { font-size: 14.5px; color: var(--text); padding-left: 24px; position: relative; margin-bottom: 10px; line-height: 1.55; }
.pc.pros li::before { content: "✓"; position: absolute; left: 0; color: var(--green); font-weight: 700; }
.pc.cons li::before { content: "✕"; position: absolute; left: 0; color: var(--red); font-weight: 700; }

/* table */
.table-wrap { overflow-x: auto; margin: 22px 0; border: 1px solid var(--line); border-radius: var(--radius); }
table.cmp { width: 100%; border-collapse: collapse; font-size: 14.5px; min-width: 560px; }
table.cmp th { background: var(--bg-soft); text-align: left; padding: 13px 16px; font-family: var(--fd); font-size: 13.5px; color: var(--ink); border-bottom: 1px solid var(--line); }
table.cmp td { padding: 12px 16px; border-bottom: 1px solid var(--line); color: var(--text); vertical-align: top; }
table.cmp tr:last-child td { border-bottom: 0; }
table.cmp td:first-child { font-weight: 600; color: var(--ink); white-space: nowrap; }

/* FAQ */
.faq { margin: 14px 0; }
.faq details { background: var(--paper); border: 1px solid var(--line); border-radius: 12px; margin-bottom: 12px; }
.faq summary { cursor: pointer; padding: 18px 22px; font-family: var(--fd); font-weight: 600; font-size: 16px; color: var(--ink); list-style: none; display: flex; justify-content: space-between; gap: 14px; align-items: center; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--brand); font-size: 22px; transition: transform .2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq .faq-a { padding: 0 22px 18px; color: var(--slate); font-size: 15px; line-height: 1.7; }

.callout { background: var(--bg-soft); border-left: 4px solid var(--amber); border-radius: 0 10px 10px 0; padding: 16px 20px; margin: 22px 0; font-size: 15px; color: var(--ink-2); }
.callout strong { color: var(--ink); }

.disclaimer { font-size: 13px; color: var(--muted); border-top: 1px solid var(--line); padding-top: 20px; margin-top: 40px; line-height: 1.6; }

/* Footer */
.site-footer { border-top: 1px solid var(--line); background: var(--bg-soft); padding-block: 40px 28px; margin-top: 30px; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 16px; }
.footer-inner .brand { margin-bottom: 0; }
.footer-inner p { font-size: 13px; color: var(--muted); }
.footer-social { display: flex; gap: 18px; }
.footer-social a { font-size: 13.5px; color: var(--slate); text-decoration: none; }
.footer-social a:hover { color: var(--brand-deep); }

.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }