/* Cashy Oversight Challenge - site styles
   Plain CSS, no build step. Colour tokens on :root; dark mode via prefers-color-scheme. */

:root {
  --bg: #F7F8FA;
  --surface: #FFFFFF;
  --surface-2: #EEF2F6;
  --ink: #16202A;
  --ink-2: #4A5866;
  --ink-3: #74828F;
  --line: #D9E0E7;
  --accent: #0B5FA5;
  --accent-ink: #FFFFFF;
  --accent-soft: #E3EEF8;
  --accent-2: #7FB0DB;
  --warn: #B4531B;
  --warn-soft: #FBEDE3;
  --radius: 6px;
  --maxw: 1180px;
  --font: "IBM Plex Sans", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, monospace;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0F1519;
    --surface: #161D23;
    --surface-2: #1E272F;
    --ink: #E8EDF1;
    --ink-2: #B4BFC9;
    --ink-3: #8593A0;
    --line: #2B3640;
    --accent: #5FA3E0;
    --accent-ink: #0F1519;
    --accent-soft: #17293A;
    --accent-2: #2E5F8C;
    --warn: #E8895A;
    --warn-soft: #3A261B;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }

h1, h2, h3, h4 { line-height: 1.15; margin: 0 0 .5em; letter-spacing: -0.01em; }
h1 { font-size: clamp(2rem, 4.2vw, 3.1rem); font-weight: 600; }
h2 { font-size: clamp(1.6rem, 2.8vw, 2.2rem); font-weight: 600; }
h3 { font-size: 1.2rem; font-weight: 600; }
h4 { font-size: 1rem; font-weight: 600; }
p { margin: 0 0 1em; }
.lead { font-size: 1.15rem; color: var(--ink-2); max-width: 62ch; }
.muted { color: var(--ink-3); }
.small { font-size: .9rem; }
.prose { max-width: 68ch; }
.prose p { color: var(--ink-2); }
.prose strong { color: var(--ink); }
.num { font-family: var(--mono); font-variant-numeric: tabular-nums; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
section { padding: 72px 0; border-top: 1px solid var(--line); }
section:first-of-type { border-top: 0; }
.section-head { max-width: 68ch; margin-bottom: 36px; }
.section-head p { color: var(--ink-2); }

/* Skip link */
.skip { position: absolute; left: -999px; top: 8px; background: var(--accent); color: var(--accent-ink); padding: 8px 12px; border-radius: var(--radius); z-index: 100; }
.skip:focus { left: 8px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-weight: 600; white-space: nowrap; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.brand span small { display: block; font-weight: 400; color: var(--ink-3); font-size: .72rem; line-height: 1; margin-top: 2px; }
nav.primary ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 22px; }
nav.primary a { color: var(--ink-2); text-decoration: none; font-size: .95rem; padding: 6px 0; }
nav.primary a:hover { color: var(--ink); }
.nav-toggle { display: none; background: none; border: 1px solid var(--line); border-radius: var(--radius); color: var(--ink); padding: 6px 10px; font: inherit; cursor: pointer; }
@media (max-width: 900px) {
  .nav-toggle { display: inline-block; }
  nav.primary { display: none; position: absolute; left: 0; right: 0; top: 64px; background: var(--surface); border-bottom: 1px solid var(--line); padding: 12px 20px 18px; }
  nav.primary.open { display: block; }
  nav.primary ul { flex-direction: column; gap: 10px; }
}

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 11px 18px; border-radius: var(--radius); font-weight: 600; text-decoration: none; border: 1px solid transparent; font-size: .95rem; white-space: nowrap; transition: transform .08s ease, background .15s ease; }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary .todo { border-color: color-mix(in srgb, var(--accent-ink) 60%, transparent); color: var(--accent-ink); }
.btn-primary:hover { background: color-mix(in srgb, var(--accent) 88%, var(--ink)); }
.btn-secondary { background: var(--surface); color: var(--ink); border-color: var(--line); }
.btn-secondary:hover { border-color: var(--ink-3); }

/* Hero */
.hero { padding: 64px 0 56px; border-top: 0; }
.hero .grid { display: grid; grid-template-columns: 7fr 5fr; gap: 48px; align-items: center; }
.hero .eyebrow { font-size: .8rem; text-transform: uppercase; letter-spacing: .14em; color: var(--accent); font-weight: 600; margin-bottom: 14px; }
.hero h1 { margin-bottom: 16px; max-width: 22ch; }
.hero .lead { margin-bottom: 26px; }
.hero .cta { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-visual { display: flex; justify-content: center; }
.hero-visual .mark { width: min(300px, 70%); height: auto; aspect-ratio: 1; border-radius: 22%; box-shadow: 0 30px 60px -30px color-mix(in srgb, var(--accent) 45%, transparent); }
@media (max-width: 900px) {
  .hero { padding: 40px 0 44px; }
  .hero .grid { grid-template-columns: 1fr; gap: 28px; }
  .hero-visual { order: -1; }
  .hero-visual .mark { width: 120px; border-radius: 22%; }
}

/* Stat strip */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); overflow: hidden; }
.stat { padding: 22px 22px 20px; border-left: 1px solid var(--line); }
.stat:first-child { border-left: 0; }
.stat .value { font-family: var(--mono); font-size: 2rem; font-weight: 600; line-height: 1; color: var(--ink); }
.stat .value small { font-size: 1rem; color: var(--ink-3); font-weight: 400; }
.stat .label { color: var(--ink-2); font-size: .9rem; margin-top: 8px; line-height: 1.4; }
.stat .arrow { color: var(--warn); }
@media (max-width: 900px) {
  .stats { grid-template-columns: 1fr 1fr; }
  .stat:nth-child(3) { border-left: 0; }
  .stat:nth-child(n+3) { border-top: 1px solid var(--line); }
}
@media (max-width: 520px) {
  .stats { grid-template-columns: 1fr; }
  .stat { border-left: 0; border-top: 1px solid var(--line); }
  .stat:first-child { border-top: 0; }
}

/* Two-column text layouts */
.cols { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.cols-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
@media (max-width: 900px) { .cols, .cols-3 { grid-template-columns: 1fr; gap: 24px; } }

/* Pull quote / the question */
.question {
  margin: 44px 0 0;
  padding: 32px 36px;
  background: var(--accent-soft);
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
}
.question p { font-size: clamp(1.15rem, 2vw, 1.45rem); line-height: 1.4; margin: 0; font-weight: 500; }
.question .tag { font-size: .8rem; text-transform: uppercase; letter-spacing: .12em; color: var(--accent); font-weight: 600; margin-bottom: 10px; }
@media (max-width: 600px) { .question { padding: 22px 20px; } }

/* Three-feature list */
.features { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border-top: 1px solid var(--line); }
.features li { padding: 22px 24px 22px 0; border-right: 1px solid var(--line); margin-right: 24px; }
.features li:last-child { border-right: 0; margin-right: 0; }
.features h4 { margin-bottom: 6px; }
.features p { color: var(--ink-2); margin: 0; font-size: .95rem; }
@media (max-width: 900px) { .features { grid-template-columns: 1fr; } .features li { border-right: 0; margin-right: 0; border-bottom: 1px solid var(--line); padding-right: 0; } .features li:last-child { border-bottom: 0; } }

/* Tracks grid */
.tracks { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.track { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; display: flex; flex-direction: column; gap: 10px; }
.track h3 { font-size: 1.05rem; margin: 0; }
.track p { color: var(--ink-2); font-size: .95rem; margin: 0; }
.track .kind { font-family: var(--mono); font-size: .75rem; color: var(--accent); }
.track.featured { background: var(--accent-soft); border-color: transparent; }
@media (max-width: 900px) { .tracks { grid-template-columns: 1fr 1fr; } }
@media (max-width: 600px) { .tracks { grid-template-columns: 1fr; } }

/* Numbered steps */
.steps { counter-reset: step; list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.steps li { counter-increment: step; padding-top: 14px; border-top: 2px solid var(--accent); }
.steps li::before { content: counter(step, decimal-leading-zero); font-family: var(--mono); color: var(--accent); font-size: .85rem; display: block; margin-bottom: 8px; }
.steps h4 { margin-bottom: 6px; }
.steps p { color: var(--ink-2); margin: 0; font-size: .95rem; }
@media (max-width: 900px) { .steps { grid-template-columns: 1fr; } }

/* Charts */
.charts { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 32px 0; }
.chart { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 18px 12px; min-width: 0; }
.chart.wide { grid-column: span 2; }
.chart h4 { margin: 0 0 2px; font-size: .95rem; }
.chart .sub { color: var(--ink-3); font-size: .82rem; margin: 0 0 10px; }
.chart svg { width: 100%; height: auto; display: block; overflow: visible; }
.chart .legend { display: flex; gap: 16px; font-size: .8rem; color: var(--ink-2); margin-top: 6px; }
.chart .legend span::before { content: ""; display: inline-block; width: 10px; height: 10px; border-radius: 2px; margin-right: 6px; vertical-align: -1px; background: var(--sw); }
.chart text { font-family: var(--font); fill: var(--ink-2); font-size: 11px; }
.chart text.val { font-family: var(--mono); fill: var(--ink); }
.chart line.grid { stroke: var(--line); }
.chart line.axis { stroke: var(--ink-3); }
.chart rect.bar { fill: var(--accent); rx: 3; }
.chart rect.bar.soft { fill: var(--accent-2); }
.chart rect.bar:hover, .chart rect.bar.soft:hover { opacity: .8; }
@media (max-width: 800px) { .charts { grid-template-columns: 1fr; } .chart.wide { grid-column: span 1; } }

/* Tables */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: .92rem; }
th, td { text-align: left; padding: 10px 14px; vertical-align: top; border-bottom: 1px solid var(--line); }
th { background: var(--surface-2); font-weight: 600; font-size: .85rem; color: var(--ink-2); white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
td code, .code { font-family: var(--mono); font-size: .85em; background: var(--surface-2); padding: 1px 6px; border-radius: 4px; white-space: nowrap; }
td .num { font-size: .9em; }
tbody tr:nth-child(even) td { background: color-mix(in srgb, var(--surface-2) 45%, transparent); }

/* Details / accordions */
details { border-top: 1px solid var(--line); }
details:last-of-type { border-bottom: 1px solid var(--line); }
summary { cursor: pointer; padding: 16px 0; font-weight: 600; list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 12px; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; font-family: var(--mono); color: var(--ink-3); font-size: 1.2rem; flex: 0 0 auto; }
details[open] summary::after { content: "\2013"; }
details .body { padding: 0 0 20px; color: var(--ink-2); max-width: 72ch; }
details .body p:last-child { margin-bottom: 0; }
details .body ul { padding-left: 20px; }
details.wide .body { max-width: none; }

/* Notice */
.notice { display: grid; grid-template-columns: auto 1fr; gap: 14px; padding: 18px 20px; border: 1px solid var(--line); border-left: 4px solid var(--warn); background: var(--warn-soft); border-radius: 0 var(--radius) var(--radius) 0; color: var(--ink); }
.notice strong { display: block; margin-bottom: 4px; }
.notice p { margin: 0; font-size: .95rem; color: var(--ink-2); }

/* Placeholder (logistics TODO) */
.todo { border: 1px dashed var(--ink-3); border-radius: var(--radius); padding: 4px 8px; font-family: var(--mono); font-size: .8rem; color: var(--ink-3); white-space: nowrap; }

/* Logistics grid */
.facts { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.fact { padding: 20px 20px 20px 0; }
.fact .k { font-size: .8rem; text-transform: uppercase; letter-spacing: .1em; color: var(--ink-3); margin-bottom: 6px; }
.fact .v { font-size: 1.05rem; font-weight: 600; }
@media (max-width: 900px) { .facts { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .facts { grid-template-columns: 1fr; } }

/* Criteria */
.criteria { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.criterion { padding: 20px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); display: flex; flex-direction: column; }
.criterion .pct { font-family: var(--mono); font-size: 1.8rem; font-weight: 600; color: var(--accent); line-height: 1; }
.criterion h4 { margin: 10px 0 4px; }
.criterion p { margin: 0; color: var(--ink-2); font-size: .92rem; }
.criterion .bar { height: 4px; background: var(--accent-soft); border-radius: 2px; margin-top: auto; overflow: hidden; }
.criterion p { margin-bottom: 14px; }
.criterion .bar i { display: block; height: 100%; background: var(--accent); }
@media (max-width: 900px) { .criteria { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .criteria { grid-template-columns: 1fr; } }

/* Requirement list */
.reqs { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 14px 32px; }
.reqs li { padding-left: 18px; position: relative; color: var(--ink-2); font-size: .97rem; }
.reqs li::before { content: ""; position: absolute; left: 0; top: .6em; width: 8px; height: 8px; border-radius: 2px; background: var(--accent); }
.reqs li strong { color: var(--ink); }
@media (max-width: 800px) { .reqs { grid-template-columns: 1fr; } }

/* Resources */
.resources { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.resources h4 { margin-bottom: 10px; padding-bottom: 8px; border-bottom: 1px solid var(--line); }
.resources ul { list-style: none; padding: 0; margin: 0; }
.resources li { padding: 6px 0; font-size: .93rem; line-height: 1.45; }
.resources li a { color: var(--ink); }
.resources li span { color: var(--ink-3); }
@media (max-width: 900px) { .resources { grid-template-columns: 1fr; } }

/* Team */
.people { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.person { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.person .name { font-weight: 600; }
.person .role { color: var(--ink-2); font-size: .93rem; }
.person a { font-size: .9rem; }
@media (max-width: 900px) { .people { grid-template-columns: 1fr; } }

/* Footer */
footer { border-top: 1px solid var(--line); padding: 36px 0 48px; color: var(--ink-3); font-size: .88rem; }
footer .wrap { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
footer a { color: var(--ink-2); }

/* Targeting flow: interview to cash (5 steps) */
.flow { counter-reset: flow; list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; }
.flow li { counter-increment: flow; position: relative; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 16px 18px; }
.flow li::before { content: counter(flow); display: inline-grid; place-items: center; width: 26px; height: 26px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); font-family: var(--mono); font-size: .8rem; font-weight: 600; margin-bottom: 10px; }
.flow li:not(:last-child)::after { content: "\2192"; position: absolute; right: -13px; top: 18px; color: var(--ink-3); font-size: 1rem; background: var(--bg); line-height: 1; padding: 2px 0; }
.flow li.ai { background: var(--accent-soft); border-color: transparent; }
.flow h4 { margin-bottom: 6px; font-size: 1rem; }
.flow p { margin: 0; color: var(--ink-2); font-size: .9rem; line-height: 1.5; }
@media (max-width: 1000px) { .flow { grid-template-columns: 1fr; gap: 10px; } .flow li { display: grid; grid-template-columns: 26px 1fr; column-gap: 14px; } .flow li::before { grid-row: span 2; margin: 0; } .flow li:not(:last-child)::after { content: none; } }

/* Two challenge questions */
.questions { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.questions .question { margin: 0; background: var(--surface); border: 1px solid var(--line); border-left: 4px solid var(--accent-2); }
.questions .question.core { background: var(--accent-soft); border-color: transparent; border-left-color: var(--accent); }
.questions .question p { font-size: clamp(1.1rem, 1.7vw, 1.3rem); }
.questions .why { margin-top: 14px; color: var(--ink-2); font-size: .93rem; }
@media (max-width: 900px) { .questions { grid-template-columns: 1fr; } }

/* Key definitions (Annex I) */
.defs { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 18px; }
.def { background: var(--surface); border: 1px solid var(--line); border-top: 3px solid var(--accent-2); border-radius: var(--radius); padding: 18px 20px; }
.def.target { border-top-color: var(--accent); background: var(--accent-soft); }
.def.missing { border-top-color: var(--warn); }
.def .k { font-size: .8rem; color: var(--ink-3); margin-bottom: 6px; }
.def .k code { font-family: var(--mono); font-size: .85rem; background: var(--surface-2); padding: 1px 6px; border-radius: 4px; color: var(--ink); }
.def h4 { margin-bottom: 6px; }
.def p { margin: 0; color: var(--ink-2); font-size: .92rem; }
.def p code { font-family: var(--mono); font-size: .82em; }
@media (max-width: 900px) { .defs { grid-template-columns: 1fr; } }

/* Data dictionary table */
#annex-1 { margin-top: 8px; }
.dict tr.group td { background: var(--surface-2); font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; color: var(--ink-2); font-weight: 600; padding-top: 12px; }
.dict td:nth-child(2) { font-weight: 600; white-space: nowrap; }
.dict tr.absent td { color: var(--ink-3); font-style: italic; }
@media (max-width: 700px) { .dict td:nth-child(2) { white-space: normal; } }

/* Reading list as accordions */
.refs { list-style: none; padding: 0 !important; margin: 0; }
.refs li { padding: 5px 0; font-size: .93rem; line-height: 1.45; }
.refs li a { color: var(--ink); }
.refs li span { color: var(--ink-3); }

@media (max-width: 520px) { .btn { white-space: normal; text-align: center; } }