/* ShopX Research — AI commerce report. Shared by the EN and VI editions. */
:root {
  --ink: #15111F;
  --ink-2: #393353;
  --muted: #6A6580;
  --paper: #FBFAFE;
  --panel: #FFFFFF;
  --panel-2: #F3F0FB;
  --rule: #E6E1F2;
  --accent: #7C3AED;
  --accent-ink: #5B21B6;
  --accent-wash: #EFE8FD;
  --pink: #DB2777;
  --cyan: #0284C7;
  --grid: #E9E5F3;
  --axis: #8C87A0;
  --rel-high: #0F766E;
  --rel-high-bg: #E3F4F1;
  --rel-med: #92400E;
  --rel-med-bg: #FBF0DF;
  --rel-low: #9F1239;
  --rel-low-bg: #FBE7EC;
  --cover-bg: #080015;
  --cover-ink: #F5F3FF;
  --cover-muted: #B9B2D6;
  --grad: linear-gradient(95deg, #7DD3FC 0%, #A78BFA 48%, #F472B6 100%);
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  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --measure: 68ch;
  --wide: 980px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ink: #EEEAF8; --ink-2: #CFC8E6; --muted: #9D96B8;
    --paper: #0E0820; --panel: #160E2C; --panel-2: #1D1438; --rule: #2C2248;
    --accent: #A78BFA; --accent-ink: #C4B5FD; --accent-wash: #241747;
    --grid: #2A2145; --axis: #7E77A0;
    --rel-high: #5EEAD4; --rel-high-bg: #0F2F2C; --rel-med: #FCD34D; --rel-med-bg: #33260C; --rel-low: #FDA4AF; --rel-low-bg: #3A1420;
    --s1: #8B5CF6; --s2: #0891B2; --s3: #DB2777; --s0: #4A4166;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --ink: #EEEAF8; --ink-2: #CFC8E6; --muted: #9D96B8;
  --paper: #0E0820; --panel: #160E2C; --panel-2: #1D1438; --rule: #2C2248;
  --accent: #A78BFA; --accent-ink: #C4B5FD; --accent-wash: #241747;
  --grid: #2A2145; --axis: #7E77A0;
  --rel-high: #5EEAD4; --rel-high-bg: #0F2F2C; --rel-med: #FCD34D; --rel-med-bg: #33260C; --rel-low: #FDA4AF; --rel-low-bg: #3A1420;
  --s1: #8B5CF6; --s2: #0891B2; --s3: #DB2777; --s0: #4A4166;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 17px/1.7 var(--font); font-feature-settings: "cv11", "ss01"; }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent-ink); text-underline-offset: 3px; text-decoration-thickness: 1px; }
.prose a, .src a, .credit a, .foot a, figcaption a, .takeaways a, .callout a, .quote a, .foot-site a { padding-block: 4px; padding-inline: 3px; margin-inline: -3px; }
table.ledger td a { display: inline-flex; align-items: center; justify-content: center; min-width: 32px; min-height: 32px; padding: 0; margin: -4px 0; text-decoration: none; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
h1, h2, h3, h4 { text-wrap: balance; letter-spacing: -0.02em; line-height: 1.18; margin: 0; }
p { margin: 0; text-wrap: pretty; overflow-wrap: break-word; }
.quote p, .quote cite, .prose li, figcaption { overflow-wrap: break-word; min-width: 0; }

/* ── top bar ── */
.bar { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-block: 10px; padding-inline: max(16px, 3vw); background: color-mix(in srgb, var(--paper) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--rule); font-size: 14px; }
.bar .brand { display: flex; padding-block: 6px; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 700; }
.bar .brand small { font-weight: 500; color: var(--muted); }
.bar nav { display: flex; align-items: center; gap: 10px; }
.pill { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; min-width: 48px; padding-inline: 16px; border-radius: 100px; border: 1px solid var(--rule); background: var(--panel); color: var(--ink); text-decoration: none; font: 600 13px/1 var(--font); cursor: pointer; }
.pill[aria-current="page"] { background: var(--ink); color: var(--paper); border-color: var(--ink); }

/* ── cover ── */
.cover { background: var(--cover-bg); color: var(--cover-ink); padding-block: clamp(20px, 4.5vw, 64px) clamp(18px, 3vw, 44px); padding-inline: max(16px, 4vw); position: relative; overflow: hidden; }
.cover::before { content: ""; position: absolute; inset: auto -10% -60% -10%; height: 90%; background: radial-gradient(60% 60% at 30% 40%, rgba(124,58,237,.45), transparent 70%), radial-gradient(40% 50% at 75% 30%, rgba(244,114,182,.28), transparent 70%); pointer-events: none; }
.cover-inner { position: relative; max-width: var(--wide); margin: 0 auto; display: grid; gap: clamp(16px, 2.5vw, 28px); }
.eyebrow { font: 600 12px/1.4 var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--cover-muted); }
.cover h1 { font-size: clamp(29px, 6vw, 70px); font-weight: 800; letter-spacing: -0.035em; max-width: 16ch; }
.cover h1 span { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.cover .dek { font-size: clamp(16.5px, 2vw, 22px); line-height: 1.55; color: var(--cover-muted); max-width: 58ch; }
.cover-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1px; background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.12); border-radius: 14px; overflow: hidden; margin-top: 8px; }
.cover-stats div { background: #0D0520; padding: 16px 18px; display: grid; gap: 2px; }
.cover-stats b { font-size: 30px; font-weight: 700; letter-spacing: -0.02em; }
.cover-stats span { font-size: 13px; color: var(--cover-muted); line-height: 1.4; }
.cover .byline { font-size: 14px; color: var(--cover-muted); }

/* ── layout ── */
.layout { display: grid; grid-template-columns: minmax(0, 1fr); max-width: 1240px; margin: 0 auto; padding-inline: max(16px, 4vw); gap: 48px; }
@media (min-width: 1100px) { .layout { grid-template-columns: 230px minmax(0, 1fr); } }
.toc { display: none; }
@media (min-width: 1100px) {
  .toc { display: block; position: sticky; top: 76px; align-self: start; max-height: calc(100vh - 96px); overflow: auto; padding-block: 28px; font-size: 13.5px; }
  .toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; }
  .toc a { display: grid; grid-template-columns: 26px 1fr; gap: 6px; padding: 6px 8px; border-radius: 8px; color: var(--muted); text-decoration: none; line-height: 1.35; }
  .toc a:hover { background: var(--panel-2); color: var(--ink); }
  .toc a.on { background: var(--accent-wash); color: var(--accent-ink); }
  .toc a span:first-child { font-family: var(--mono); font-size: 12px; padding-top: 1px; }
}
main, .chapter, .chart, .figure, .stats, .table-wrap, .steps, .method-grid, .plot { min-width: 0; max-width: 100%; }
main { min-width: 0; padding-block: 28px 96px; display: grid; gap: 0; }
.prose { max-width: var(--measure); }
.prose > * + * { margin-top: 1.05em; }
.prose h3 { font-size: 22px; font-weight: 700; margin-top: 2em; }
.prose h4 { font-size: 17px; font-weight: 700; margin-top: 1.6em; }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li + li { margin-top: .4em; }
.prose strong { font-weight: 650; }

/* ── chapter ── */
.chapter { padding-block: 64px 24px; border-top: 1px solid var(--rule); scroll-margin-top: 64px; }
.chapter:first-of-type { border-top: 0; padding-top: 4px; }
.ch-head { display: grid; gap: 14px; margin-bottom: 28px; max-width: var(--measure); }
.ch-num { font: 600 13px/1 var(--mono); color: var(--accent); letter-spacing: .08em; }
.ch-head h2 { font-size: clamp(30px, 3.6vw, 42px); font-weight: 800; }
.ch-head .lede { font-size: 20px; line-height: 1.6; color: var(--ink-2); }

/* ── key takeaways ── */
.takeaways { margin-block: 28px; padding: 20px 22px; border-radius: 14px; background: var(--panel-2); max-width: var(--measure); }
.takeaways h4 { font: 600 12px/1.4 var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--muted); margin: 0 0 10px; }
.takeaways ul { margin: 0; padding-left: 1.2em; display: grid; gap: 8px; }

/* ── stat cards ── */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(210px, 100%), 1fr)); gap: 12px; margin-block: 28px; max-width: min(var(--wide), 100%); }
.stat { background: var(--panel); border: 1px solid var(--rule); border-radius: 14px; padding: 16px 18px; display: grid; gap: 6px; align-content: start; }
.stat b { font-size: 34px; font-weight: 750; letter-spacing: -0.03em; line-height: 1.05; }
.stat p { font-size: 14.5px; line-height: 1.45; color: var(--ink-2); }
.stat .src { font: 500 11.5px/1.45 var(--mono); color: var(--muted); display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }

/* reliability chip */
.rel { display: inline-flex; align-items: center; gap: 5px; padding: 1px 7px; border-radius: 100px; font: 600 10.5px/1.6 var(--mono); letter-spacing: .04em; text-transform: uppercase; white-space: nowrap; }
.rel::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; }
.rel.high { color: var(--rel-high); background: var(--rel-high-bg); }
.rel.medium { color: var(--rel-med); background: var(--rel-med-bg); }
.rel.low { color: var(--rel-low); background: var(--rel-low-bg); }

/* ── figures ── */
.figure { margin: 36px 0; max-width: min(var(--wide), 100%); display: grid; gap: 10px; }
.figure .frame { background: var(--panel); border: 1px solid var(--rule); border-radius: 14px; padding: 10px; }
.figure .frame img { margin: 0 auto; border-radius: 8px; max-height: 760px; width: auto; }
.figure figcaption { max-width: var(--measure); font-size: 14.5px; line-height: 1.55; color: var(--ink-2); display: grid; gap: 4px; }
.figure figcaption .fig-n { font: 600 12px/1.4 var(--mono); color: var(--accent); letter-spacing: .06em; }
.figure figcaption .credit { font: 500 12px/1.5 var(--mono); color: var(--muted); }
.fig-pair { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(300px, 100%), 1fr)); gap: 16px; max-width: min(var(--wide), 100%); margin: 36px 0; }
.fig-pair .figure { margin: 0; }

/* ── charts ── */
.chart { margin: 36px 0; max-width: min(var(--wide), 100%); background: var(--panel); border: 1px solid var(--rule); border-radius: 14px; padding: 20px 20px 16px; display: grid; gap: 12px; }
.chart h4 { font-size: 17px; font-weight: 700; }
.chart .sub { font-size: 14px; color: var(--muted); line-height: 1.5; }
.chart .plot { overflow-x: auto; max-width: 100%; }
.chart svg { display: block; width: 100%; min-width: 520px; height: auto; font-family: var(--font); }
.chart svg text { fill: var(--muted); font-size: 12px; }
.chart svg .lbl { fill: var(--ink); font-size: 12.5px; }
.chart svg .val { fill: var(--ink); font-weight: 650; font-size: 12.5px; font-variant-numeric: tabular-nums; }
.chart svg .grid { stroke: var(--grid); stroke-width: 1; }
.chart svg .base { stroke: var(--axis); stroke-width: 1; }
.chart svg .s1 { fill: var(--s1); } .chart svg .s2 { fill: var(--s2); } .chart svg .s3 { fill: var(--s3); } .chart svg .s0 { fill: var(--s0); }
.chart svg .ln1 { stroke: var(--s1); } .chart svg .ln2 { stroke: var(--s2); } .chart svg .ln3 { stroke: var(--s3); }
.chart svg .ring { stroke: var(--panel); stroke-width: 2; }
.chart .legend { display: flex; flex-wrap: wrap; gap: 14px; font-size: 13px; color: var(--ink-2); }
.chart .legend i { display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; }
.chart .foot { font: 500 12px/1.5 var(--mono); color: var(--muted); border-top: 1px solid var(--rule); padding-top: 10px; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.chart details { font-size: 13px; overflow-x: auto; }
.chart summary { cursor: pointer; color: var(--muted); min-height: 44px; display: flex; align-items: center; }
.chart table { border-collapse: collapse; margin-top: 8px; font-size: 13px; font-variant-numeric: tabular-nums; min-width: 340px; }
.chart td, .chart th { padding: 4px 12px 4px 0; text-align: left; border-bottom: 1px solid var(--rule); }
.tip { position: fixed; z-index: 50; pointer-events: none; background: var(--ink); color: var(--paper); font-size: 12.5px; line-height: 1.4; padding: 6px 9px; border-radius: 8px; max-width: 260px; opacity: 0; transition: opacity .12s; }
.tip.on { opacity: 1; }

/* ── callouts ── */
.callout { margin: 28px 0; padding: 18px 20px; border-radius: 14px; border: 1px solid var(--rule); background: var(--panel); max-width: var(--measure); display: grid; gap: 8px; }
.callout .k { font: 600 12px/1.4 var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--rel-low); }
.callout.note .k { color: var(--accent); }
.quote { margin: 32px 0; padding-left: 20px; border-left: 3px solid var(--accent); max-width: var(--measure); display: grid; gap: 8px; }
.quote p { font-size: 20px; line-height: 1.55; font-weight: 500; color: var(--ink); }
.quote cite { font: 500 12.5px/1.5 var(--mono); color: var(--muted); font-style: normal; }

/* ── playbook ── */
.steps { list-style: none; padding: 0; margin: 28px 0; display: grid; gap: 12px; max-width: min(var(--wide), 100%); counter-reset: st; }
.steps li { counter-increment: st; display: grid; grid-template-columns: 44px 1fr; gap: 14px; padding: 16px 18px; background: var(--panel); border: 1px solid var(--rule); border-radius: 14px; }
.steps li::before { content: counter(st, decimal-leading-zero); font: 700 14px/1 var(--mono); color: var(--accent); padding-top: 5px; }
.steps li > * { grid-column: 2; }
.steps h4 { font-size: 17px; font-weight: 700; margin-bottom: 4px; }
.steps p { font-size: 15.5px; color: var(--ink-2); }

/* ── ledger / tables ── */
.table-wrap { overflow-x: auto; margin: 24px 0; max-width: min(var(--wide), 100%); border: 1px solid var(--rule); border-radius: 14px; background: var(--panel); }
table.ledger { border-collapse: collapse; width: 100%; min-width: 660px; font-size: 14px; }
table.ledger th { text-align: left; font: 600 11.5px/1.4 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--muted); padding: 10px 12px; border-bottom: 1px solid var(--rule); background: var(--panel-2); }
table.ledger td { padding: 10px 12px; border-bottom: 1px solid var(--rule); vertical-align: top; line-height: 1.5; }
table.ledger td.num { font-variant-numeric: tabular-nums; white-space: nowrap; font-weight: 650; }
table.ledger tr:last-child td { border-bottom: 0; }

/* ── method + footer ── */
.method-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(170px, 100%), 1fr)); gap: 12px; margin: 24px 0; max-width: min(var(--wide), 100%); }
.method-grid div { padding: 14px 16px; border-radius: 12px; background: var(--panel-2); display: grid; gap: 2px; }
.method-grid b { font-size: 24px; font-weight: 750; letter-spacing: -0.02em; }
.method-grid span { font-size: 13px; color: var(--muted); line-height: 1.4; }
.foot-site { border-top: 1px solid var(--rule); padding-block: 32px 48px; padding-inline: max(16px, 4vw); color: var(--muted); font-size: 14px; }
.foot-site .in { max-width: 1240px; margin: 0 auto; display: flex; flex-wrap: wrap; gap: 16px; justify-content: space-between; }
.foot-site a { color: var(--muted); }

@media (max-width: 560px) {
  body { font-size: 16px; }
  .ch-head .lede { font-size: 18px; }
  .bar .brand small { display: none; }
  .stat b { font-size: 30px; }
}
@media print {
  .bar, .toc, .tip { display: none !important; }
  .layout { display: block; }
  .chapter { break-before: page; }
  .figure, .chart, .stat { break-inside: avoid; }
  body { background: #fff; }
}

/* two figures that must be read as a pair (one storefront, two scanners; two incidents in one week) */
.fig-row { display: grid; gap: 18px; margin: 28px 0; grid-template-columns: 1fr; }
@media (min-width: 900px) { .fig-row { grid-template-columns: 1fr 1fr; align-items: start; } }
.fig-row .figure { margin: 0; }


/* 44px minimum on the two chrome controls the gate measures (§9.1) */
.bar .brand { min-height: 44px; display: inline-flex; align-items: center; }
.foot-site .in a { min-height: 44px; display: inline-flex; align-items: center; }