/* app.css — one stylesheet, light and dark. System fonts, no dependencies. */
:root {
  --bg: #fbfbf9; --bg-alt: #f3f3ef; --panel: #ffffff;
  --ink: #15181d; --ink-2: #4a505a; --ink-3: #767d88;
  --line: #e3e3dc; --line-2: #d2d3cb;
  --good: #167a55; --good-bg: #e7f4ee; --bad: #a8382e; --bad-bg: #fbeae8; --accent: #1f4e79;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --shadow: 0 1px 2px rgba(20,24,30,.05), 0 8px 24px -12px rgba(20,24,30,.15);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1216; --bg-alt: #151a20; --panel: #171c22;
    --ink: #eceef1; --ink-2: #b3bac4; --ink-3: #858d99;
    --line: #242b33; --line-2: #313a44;
    --good: #56c596; --good-bg: #11271e; --bad: #ef8579; --bad-bg: #2b1715; --accent: #8ab8e6;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 10px 30px -14px rgba(0,0,0,.6);
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 70px; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.6 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
code { font-family: var(--mono); font-size: .88em; background: var(--bg-alt); padding: 1px 5px; border-radius: 4px; }
section { padding-top: 64px; }
section + section { border-top: 1px solid var(--line); }
h2 { font-size: clamp(22px, 2.6vw, 30px); line-height: 1.2; letter-spacing: -.02em; margin: 0 0 10px; font-weight: 650; }
h3 { font-size: 17px; margin: 34px 0 10px; letter-spacing: -.01em; font-weight: 620; }
h4 { margin: 0 0 6px; font-size: 15px; }
.sec-intro { max-width: 780px; color: var(--ink-2); font-size: 16.5px; margin-bottom: 26px; }
.fine { font-size: 13px; color: var(--ink-3); max-width: 840px; margin-top: 12px; }
.muted { color: var(--ink-2); }

/* header */
.top { position: sticky; top: 0; z-index: 20; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--line); }
.top-in { display: flex; align-items: center; justify-content: space-between; height: 56px; }
.brand { font-weight: 650; color: var(--ink); font-size: 15px; }
.brand::before { content: ""; display: inline-block; width: 9px; height: 9px; border-radius: 2px; background: var(--ink); margin-right: 8px; vertical-align: 1px; }
.top nav { display: flex; gap: 2px; flex-wrap: wrap; }
.top nav a { color: var(--ink-2); font-size: 13.5px; padding: 6px 9px; border-radius: 7px; }
.top nav a:hover { background: var(--bg-alt); color: var(--ink); text-decoration: none; }

/* hero */
.hero { padding-top: 72px; }
.kicker { font-size: 13px; color: var(--ink-3); text-transform: uppercase; letter-spacing: .08em; margin-bottom: 18px; }
.hero h1 { font-family: var(--serif); font-weight: 600; font-size: clamp(32px, 5vw, 54px); line-height: 1.06; letter-spacing: -.025em; margin: 0 0 22px; max-width: 20ch; }
.lede { font-size: 19px; line-height: 1.55; color: var(--ink-2); max-width: 66ch; }
.hero-nums { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-top: 40px; background: var(--line); border: 1px solid var(--line); border-radius: 14px; overflow: hidden; }
.hero-num { background: var(--panel); padding: 20px; display: flex; flex-direction: column; gap: 4px; }
.hn-label { font-size: 12px; color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; }
.hn-big { font-size: 32px; font-weight: 650; letter-spacing: -.03em; line-height: 1.1; font-variant-numeric: tabular-nums; }
.hn-sub { font-size: 13.5px; color: var(--ink-2); }

/* answer */
.big { font-family: var(--serif); font-size: clamp(21px, 2.4vw, 27px); line-height: 1.3; letter-spacing: -.01em; margin: 6px 0 18px; }
#answer-body p { max-width: 80ch; color: var(--ink-2); }
#answer-body b { color: var(--ink); }

/* findings */
.findings { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 14px; }
.finding { background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 20px 20px 16px; box-shadow: var(--shadow); }
.finding h3 { margin: 10px 0 8px; font-size: 16.5px; }
.finding p { font-size: 14.3px; color: var(--ink-2); }
.f-label { font-family: var(--mono); font-size: 11px; letter-spacing: .05em; color: var(--ink-3); }
.f-src { font-size: 12.5px; color: var(--ink-3); margin: 0; }

/* chart */
.chart { margin: 0; background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 12px 8px 4px; }
.chart svg { width: 100%; height: auto; display: block; }
.chart .grid { stroke: var(--line); stroke-width: 1; }
.chart .axis { fill: var(--ink-3); font-size: 12px; font-family: var(--mono); }
.chart .band-ok { fill: var(--good-bg); }
.chart .axis-ok { fill: var(--good); }

/* tables */
.scroll { overflow-x: auto; border: 1px solid var(--line); border-radius: 14px; background: var(--panel); }
table { border-collapse: collapse; width: 100%; font-size: 14px; }
th { text-align: left; font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-3); padding: 12px 16px; border-bottom: 1px solid var(--line); background: var(--bg-alt); white-space: nowrap; }
td { padding: 11px 16px; border-bottom: 1px solid var(--line); vertical-align: top; }
tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: var(--bg-alt); }
b.good { color: var(--good); } b.bad { color: var(--bad); }
.good { color: var(--good); } .bad { color: var(--bad); } .warn { color: var(--accent); }

/* plans */
.tabs { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 18px; }
.tab { border: 1px solid var(--line-2); background: var(--panel); color: var(--ink-2); padding: 8px 14px; border-radius: 999px; font: inherit; font-size: 13.5px; cursor: pointer; }
.tab:hover { border-color: var(--ink-3); color: var(--ink); }
.tab.on { background: var(--ink); border-color: var(--ink); color: var(--bg); }
.plan-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; align-items: start; }
.plan-card { background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 20px; box-shadow: var(--shadow); }
.plan-card.rec { border-color: var(--accent); }
.plan-card h3 { margin: 0 0 6px; font-size: 16.5px; }
.badge { font-family: var(--mono); font-size: 10.5px; text-transform: uppercase; letter-spacing: .04em; background: var(--good-bg); color: var(--good); padding: 2px 6px; border-radius: 4px; vertical-align: 2px; }
.plan-note { font-size: 13.5px; color: var(--ink-2); min-height: 4.2em; }
.plan-grid-in { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 14px; margin: 14px 0 6px; padding-top: 14px; border-top: 1px solid var(--line); }
.plan-stat { display: flex; flex-direction: column; gap: 0; }
.plan-stat span { font-size: 11.5px; color: var(--ink-3); text-transform: uppercase; letter-spacing: .05em; }
.plan-stat b { font-size: 18px; font-weight: 640; letter-spacing: -.01em; font-variant-numeric: tabular-nums; }
.plan-stat small { color: var(--ink-3); font-size: 11.5px; line-height: 1.35; }
.plan-rec { font-size: 12.8px; color: var(--ink-2); margin: 12px 0 6px; }
.plan-why { font-size: 13px; color: var(--ink-2); margin: 0; }

/* memory bars */
.bars { margin-top: 18px; display: grid; gap: 8px; max-width: 760px; }
.bar-row { display: grid; grid-template-columns: 220px 1fr 90px; gap: 12px; align-items: center; font-size: 13.5px; color: var(--ink-2); }
.bar2 { height: 14px; background: var(--bg-alt); border-radius: 4px; overflow: hidden; border: 1px solid var(--line); }
.bar2 i { display: block; height: 100%; background: var(--accent); opacity: .75; }
.bar-row b { font-family: var(--mono); font-size: 12.5px; text-align: right; color: var(--ink); }

/* alternatives + counters */
.alts { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 14px; }
.alt { background: var(--bg-alt); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; }
.alt p { font-size: 13.8px; color: var(--ink-2); margin: 0; }
.counters { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.counter { background: var(--bg-alt); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; }
.counter h4 { font-size: 14.5px; }
.counter p { font-size: 13.8px; color: var(--ink-2); margin: 0; }

/* method */
#method h3:first-child { margin-top: 0; }
ul.clean { padding-left: 18px; margin: 0 0 12px; font-size: 14.5px; color: var(--ink-2); }
ul.clean li { margin-bottom: 6px; }
ol.clean { padding-left: 20px; font-size: 14.8px; color: var(--ink-2); }
ol.clean li { margin-bottom: 10px; }
.tag { font-family: var(--mono); font-size: 10.5px; padding: 2px 6px; border-radius: 4px; letter-spacing: .04em; }
.t-spec { background: var(--bg-alt); color: var(--ink-2); }
.t-paper { background: #e8eef5; color: #1f4e79; } .t-calc { background: #e8f2ec; color: #1f6044; }
.t-model { background: #f4ecdf; color: #7d4c14; } .t-est { background: #efecf4; color: #4d3a6b; }
@media (prefers-color-scheme: dark) {
  .t-paper { background: #1b2a38; color: #9cc6ec; } .t-calc { background: #14291f; color: #8fd0ae; }
  .t-model { background: #2b2114; color: #e0b37a; } .t-est { background: #221d2b; color: #b8a7d6; }
}
.sources { padding-left: 20px; font-size: 13.8px; color: var(--ink-2); }
.sources li { margin-bottom: 8px; }
.s-label { font-family: var(--mono); font-size: 10px; color: var(--ink-3); border: 1px solid var(--line-2); padding: 1px 5px; border-radius: 3px; margin-right: 4px; }
.s-year { color: var(--ink-3); font-size: 12px; }
.foot { padding: 40px 24px 60px; color: var(--ink-3); font-size: 13px; }

@media (max-width: 900px) {
  .top nav a { padding: 6px 6px; font-size: 12.5px; }
  .hero-nums, .plan-cards, .counters { grid-template-columns: 1fr; }
  .bar-row { grid-template-columns: 150px 1fr 80px; }
  section { padding-top: 48px; }
}
@media (max-width: 620px) {
  .top nav { display: none; }
  .wrap { padding: 0 18px; }
  .hn-big { font-size: 27px; }
  .plan-grid-in { grid-template-columns: 1fr 1fr; }
}