/* Sustainable Supply Chain case study. Inter on paper white, four domain colours (warehousing blue, transport orange,
   packaging teal, returns violet, validated for colour-blind separation in light and dark), everything else in ink.
   Figures are inline SVG drawn by by.js on the page tokens. */
:root{--rule:#e9e9e6;--rule2:#d9d9d4;--panel:#f6f6f3;--card:#fff;--chip:#ececE8;--ink2:#2b2b29;
  --wh:#3b5bdb;--tr:#e8590c;--pk:#0b9a8d;--rt:#b23ccf;--bad:#d6336c;--good:#2b8a3e;
  --g0:#8f8f8a;--g1:#b8b8b2;--g3:#e2e2dd;--chat:#efeae2;--bub:#fff;--me:#d9fdd3;--wa:#008069}
@media(prefers-color-scheme:dark){:root:not([data-theme=light]){--rule:#262624;--rule2:#353532;--panel:#191918;--card:#121212;--chip:#262624;--ink2:#e4e4e0;
  --wh:#6680ee;--tr:#dc7426;--pk:#17a891;--rt:#b565d6;--bad:#e8668f;--good:#51b56b;
  --g0:#8a8a86;--g1:#5c5c58;--g3:#2a2a28;--chat:#0f1714;--bub:#202c33;--me:#005c4b;--wa:#21c063}}
:root[data-theme=dark]{--rule:#262624;--rule2:#353532;--panel:#191918;--card:#121212;--chip:#262624;--ink2:#e4e4e0;
  --wh:#6680ee;--tr:#dc7426;--pk:#17a891;--rt:#b565d6;--bad:#e8668f;--good:#51b56b;
  --g0:#8a8a86;--g1:#5c5c58;--g3:#2a2a28;--chat:#0f1714;--bub:#202c33;--me:#005c4b;--wa:#21c063}
:root{--wh-s:color-mix(in srgb,var(--wh) 12%,var(--card));--tr-s:color-mix(in srgb,var(--tr) 12%,var(--card));--pk-s:color-mix(in srgb,var(--pk) 12%,var(--card));--rt-s:color-mix(in srgb,var(--rt) 12%,var(--card))}

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main.by{max-width:1248px;padding-inline:40px}
.by .back{margin-bottom:96px}
.by article{line-height:1.7;min-width:0}
.by section{margin-top:168px;scroll-margin-top:40px}
.by .prose{max-width:660px}
.by h2{font-size:32px;line-height:1.25;font-weight:500;color:var(--strong);letter-spacing:-.02em;margin-bottom:24px}
.by h3{font-size:16px;line-height:1.4;font-weight:500;color:var(--strong);margin-bottom:6px}
.by .prose p{font-size:18px;color:var(--text);margin-bottom:20px}
.by .prose p:last-child{margin-bottom:0}
.by figure{margin:0}
.by figcaption,.by .cap{font-size:14px;line-height:1.6;color:var(--soft);margin:20px 0 0;max-width:720px}
.by .src{font-size:12px;line-height:1.6;color:var(--muted);margin:24px 0 0;max-width:760px}
.by .src a{color:inherit}
.by .defs{position:absolute}
.by b{font-weight:600}

/* Contents rail, as on the other case studies: fixed in the left margin on wide screens, once the hero has gone. */
.by .toc{display:none}
@media(min-width:1560px){
  .by .toc{display:block;position:fixed;z-index:5;top:96px;left:max(24px,calc((100vw - 1168px) / 2 - 196px));width:150px;max-height:calc(100vh - 140px);overflow:auto;scrollbar-width:none;opacity:0;visibility:hidden;transform:translateX(-6px);transition:opacity .35s ease,transform .35s ease,visibility 0s .35s}
  html.toc-on .by .toc{opacity:1;visibility:visible;transform:none;transition:opacity .35s ease,transform .35s ease,visibility 0s}
}
.by .toc ol{list-style:none;margin:0 0 20px;padding:0}
.by .toc li{margin:0}
.by .toc a{display:block;font-size:13px;line-height:1.35;padding:4px 0 4px 12px;color:var(--muted);text-decoration:none;border-left:1px solid var(--rule);transition:color .2s,border-color .2s}
.by .toc a:hover{color:var(--strong)}
.by .toc a.on{color:var(--strong);border-left-color:var(--strong)}
.by .toc-h{font-size:12px;color:var(--strong);margin:0 0 6px;font-weight:500}

/* Hero */
.by h1{font-size:72px;line-height:1;font-weight:500;letter-spacing:-.04em;color:var(--strong);margin-bottom:28px}
.by .lede{font-size:24px;line-height:1.45;max-width:780px;color:var(--text);margin-bottom:64px;letter-spacing:-.005em}
.by .facts{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:32px;border-top:1px solid var(--rule);padding-top:24px;margin:0 0 72px}
.by .facts dt{font-size:13px;color:var(--muted);margin-bottom:4px}
.by .facts dd{margin:0;font-size:15px;line-height:1.5;color:var(--strong)}

/* Parts */
.by .part{margin-top:200px;padding-top:40px;border-top:1px solid var(--strong);scroll-margin-top:40px}
.by .part h2{font-size:56px;line-height:1.05;letter-spacing:-.04em;margin-bottom:20px}
.by .part p{font-size:20px;line-height:1.5;color:var(--text);max-width:660px;margin:0}
.by .part+section{margin-top:96px}

/* Numbers */
.by .stats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:32px;margin-top:56px}
.by .stats.three{grid-template-columns:repeat(3,minmax(0,1fr))}
.by .stats.two{grid-template-columns:repeat(2,minmax(0,1fr));max-width:760px}
.by .stat{border-top:1px solid var(--strong);padding-top:18px}
.by .stat b{display:block;font-size:40px;line-height:1.1;font-weight:500;letter-spacing:-.03em;color:var(--strong);margin-bottom:8px;font-variant-numeric:tabular-nums}
.by .stat p{font-size:15px;line-height:1.5;color:var(--soft);margin:0;max-width:240px}
.by .targets{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1px;margin-top:56px;background:var(--rule);border:1px solid var(--rule);border-radius:18px;overflow:hidden}
.by .targets>div{background:var(--card);padding:28px 28px 30px}
.by .targets b{display:block;font-size:34px;line-height:1.1;font-weight:500;letter-spacing:-.03em;color:var(--strong);margin-bottom:10px}
.by .targets p{font-size:15px;line-height:1.5;color:var(--soft);margin:0;max-width:260px}

/* Figure panels: a label and controls on top, the drawing, a key and a live readout under it. */
.by .fig{background:var(--panel);border-radius:20px;padding:28px 32px 26px;margin-top:56px}
.by .hero-fig{margin-top:0}
.by .fig>figcaption{margin-top:22px;padding-top:18px;border-top:1px solid var(--rule)}
.by .fig-bar{display:flex;align-items:center;justify-content:space-between;gap:16px 24px;flex-wrap:wrap;margin-bottom:28px;min-height:34px}
.by .fig-n{font-size:13px;color:var(--soft);font-variant-numeric:tabular-nums}
.by .seg{display:inline-flex;gap:2px;padding:3px;border-radius:999px;background:var(--chip);max-width:100%;overflow-x:auto;scrollbar-width:none}
.by .seg::-webkit-scrollbar{display:none}
.by .seg button{flex:none;display:inline-flex;align-items:center;gap:7px;font:inherit;font-size:13px;line-height:1;padding:8px 14px;border-radius:999px;border:0;background:none;color:var(--soft);cursor:pointer;white-space:nowrap;transition:background .25s ease,color .25s ease,box-shadow .25s ease}
.by .seg button:hover{color:var(--strong)}
.by .seg button[aria-pressed=true]{background:var(--card);color:var(--strong);box-shadow:0 1px 2px #0000001a,0 0 0 1px var(--rule)}
.by .seg button:focus-visible,.by .flip:focus-visible,.by [tabindex]:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.by .seg i,.by .key i{display:inline-block;width:8px;height:8px;border-radius:50%;flex:none}
.by .seg-pair{display:flex;gap:10px;flex-wrap:wrap}
.by .fig-foot{display:flex;align-items:flex-start;justify-content:space-between;gap:12px 24px;flex-wrap:wrap;margin-top:24px;font-size:13px;line-height:1.5}
.by .fig-foot p{margin:0}
.by .hint{color:var(--soft)}
.by .readout{color:var(--strong);text-align:right;font-variant-numeric:tabular-nums;margin-left:auto;max-width:620px;min-height:1.5em}
.by .readout.left{text-align:left;margin-left:0;max-width:820px;color:var(--text)}
.by .key{display:flex;flex-wrap:wrap;gap:6px 18px;list-style:none;margin:0;padding:0;color:var(--soft)}
.by .key li{display:inline-flex;align-items:center;gap:7px}
.k-wh{background:var(--wh)}.k-tr{background:var(--tr)}.k-pk{background:var(--pk)}.k-rt{background:var(--rt)}.k-ink{background:var(--strong)}
.by .key .k-dot{background:var(--strong)}
.by .key .k-fail{background:none;border:2px solid var(--bad);width:9px;height:9px}
.by .key .k-pick{background:var(--card);border:2px solid var(--strong);width:9px;height:9px}
.by .key .k-move{background:var(--g1)}
.by .key .k-late{background:var(--tr)}
.by .plot svg{display:block;width:100%;height:auto;overflow:visible}
.by .diagram svg{max-width:1100px;margin:0 auto}

/* SVG ink */
.by .init,.by .init *{transition:none!important}
.by .c-card{color:var(--card)}
.by svg text{font-family:InterVariable,Inter,Arial,sans-serif}
.by .tx{font-size:13px;fill:var(--text)}
.by .tx-s{font-size:12px;fill:var(--soft)}
.by .tx-m{font-size:11.5px;fill:var(--muted)}
.by .tx-b{font-size:13px;font-weight:500;fill:var(--strong)}
.by .tx-h{font-size:14px;font-weight:500;fill:var(--strong)}
.by .tx-on{fill:#fff}
.by .ln{stroke:var(--rule2);stroke-width:1.25;fill:none}
.by .ln-s{stroke:var(--g0);stroke-width:1.25;fill:none}
.by .ln-k{stroke:var(--strong);stroke-width:1.5;fill:none}
.by .box{fill:var(--card);stroke:var(--rule2);stroke-width:1}
.by .box-k{fill:var(--card);stroke:var(--strong);stroke-width:1.25}
.by .mk{fill:var(--strong)}.by .mk-s{fill:var(--g0)}.by .mk-wh{fill:var(--wh)}.by .mk-tr{fill:var(--tr)}.by .mk-pk{fill:var(--pk)}.by .mk-rt{fill:var(--rt)}
.by .f-wh{fill:var(--wh)}.by .f-tr{fill:var(--tr)}.by .f-pk{fill:var(--pk)}.by .f-rt{fill:var(--rt)}
.by .fs-wh{fill:var(--wh-s)}.by .fs-tr{fill:var(--tr-s)}.by .fs-pk{fill:var(--pk-s)}.by .fs-rt{fill:var(--rt-s)}
.by .s-wh{stroke:var(--wh)}.by .s-tr{stroke:var(--tr)}.by .s-pk{stroke:var(--pk)}.by .s-rt{stroke:var(--rt)}
.by .c-wh{color:var(--wh)}.by .c-tr{color:var(--tr)}.by .c-pk{color:var(--pk)}.by .c-rt{color:var(--rt)}.by .c-soft{color:var(--soft)}.by .c-k{color:var(--strong)}.by .c-m{color:var(--g0)}
.by .ico path{fill:currentColor}
.by .hatch-bg{fill:var(--card)}
.by .hatch-ln{stroke:var(--rule2);stroke-width:2}

/* Fig 1: carbon by stage */
.by .chain .st{cursor:default;transition:opacity .45s ease}
.by .chain .st circle.c{transition:opacity .45s ease}
.by .chain .ring{fill:none;stroke:var(--strong);stroke-width:1.5;opacity:0;transition:opacity .45s ease}
.by .chain.has-sol .st:not(.on){opacity:.16}
.by .chain.has-sol .st.on .ring{opacity:1}
.by .chain .lab,.by .chain .tick{transition:opacity .45s ease}
.by .chain.has-sol .lab:not(.on),.by .chain.has-sol .tick:not(.on){opacity:.3}
.by .chain .rt-arc{transition:opacity .45s ease}
.by .chain.has-sol .rt-arc:not(.on){opacity:.16}
.by .chain .st:focus{outline:none}
.by .chain .st:focus-visible circle.c{stroke:var(--strong);stroke-width:2}
.by .tip{position:absolute;z-index:4;pointer-events:none;background:var(--card);color:var(--strong);font-size:13px;line-height:1.4;padding:8px 12px;border-radius:10px;box-shadow:0 0 0 1px var(--rule),0 10px 28px -10px #0000004d;white-space:nowrap;opacity:0;transform:translate(-50%,calc(-100% - 10px)) translateY(4px);transition:opacity .2s ease,transform .2s ease}
.by .tip.on{opacity:1;transform:translate(-50%,calc(-100% - 10px))}
.by .tip small{display:flex;align-items:center;gap:6px;color:var(--soft);font-size:12px}
.by .tip small i{width:7px;height:7px;border-radius:50%}
.by .fig{position:relative}

/* Fig 2: waffle */
.by .waffle{display:grid;grid-template-columns:minmax(0,340px) minmax(0,1fr);gap:56px;align-items:center;max-width:860px}
.by .waffle .plot svg rect{transition:opacity .3s ease}
.by .waffle.hl .plot svg rect:not(.on){opacity:.18}
.by .w0{fill:var(--g0);background:var(--g0)}.by .w1{fill:var(--g1);background:var(--g1)}.by .w2{fill:var(--strong);background:var(--strong)}.by .w3{fill:var(--g3);background:var(--g3)}
.by .big-n{font-size:48px;line-height:1;font-weight:500;letter-spacing:-.03em;color:var(--strong);margin:0 0 28px;font-variant-numeric:tabular-nums}
.by .big-n span{display:block;font-size:14px;letter-spacing:0;font-weight:400;color:var(--soft);margin-top:8px}
.by .w-legend{list-style:none;margin:0;padding:0;border-top:1px solid var(--rule)}
.by .w-legend li{display:grid;grid-template-columns:12px minmax(0,1fr) auto 48px;gap:12px;align-items:center;padding:11px 0;border-bottom:1px solid var(--rule);font-size:15px;color:var(--text);cursor:default;transition:opacity .3s ease}
.by .w-legend li i{width:12px;height:12px;border-radius:3px}
.by .w-legend li b{font-weight:500;color:var(--strong);font-variant-numeric:tabular-nums}
.by .w-legend li em{font-style:normal;color:var(--soft);text-align:right;font-variant-numeric:tabular-nums}
.by .waffle.hl .w-legend li:not(.on){opacity:.4}

/* Fig 4: priorities */
.by .prio .row{cursor:default;transition:opacity .3s ease}
.by .prio .lnk{fill:none;stroke-width:1.5;opacity:.55;transition:opacity .3s ease,stroke-width .3s ease}
.by .prio.hl .row:not(.on){opacity:.28}
.by .prio.hl .lnk:not(.on){opacity:.07}
.by .prio.hl .lnk.on{opacity:1;stroke-width:2}

/* Hero: the five chapters as a row of tiles */
.by .journey{margin:0 0 0;position:relative}
.by .journey .j-in{position:relative}
.by .journey-art{min-height:120px}
.by .journey-art svg{display:block;width:100%;height:auto}
.by .journey g[data-stop]{cursor:pointer;transition:transform .5s cubic-bezier(.2,.7,.2,1),opacity .3s ease}
.by .journey g[data-stop].on{transform:translateY(-6px)}
.by .stops{list-style:none;margin:0;padding:0;position:relative;height:44px}
.by .stops li{position:absolute;top:2px;transform:translateX(-50%);white-space:nowrap}
.by .stops a{display:inline-flex;align-items:center;gap:8px;font-size:14px;color:var(--text);text-decoration:none;padding:4px 8px;border-radius:8px;transition:color .25s ease,background .25s ease}
.by .stops a:hover,.by .stops a.on{color:var(--strong);background:var(--chip)}
.by .stops .sol-n.s{margin:0}
.by .journey>figcaption{margin:28px 0 0;max-width:720px}

/* Approach: five steps on one line */
.by .steps{list-style:none;display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:28px;margin:56px 0 0;padding:0;position:relative}
.by .steps::before{content:'';position:absolute;left:5px;right:0;top:5px;height:1px;background:var(--rule2)}
.by .steps li{position:relative}
.by .steps span{display:block;width:11px;height:11px;border-radius:50%;background:var(--strong);box-shadow:0 0 0 5px var(--bg);margin:0 0 22px;position:relative}
.by .steps b{display:block;font-size:16px;font-weight:500;color:var(--strong);margin-bottom:6px}
.by .steps p{font-size:14px;line-height:1.55;color:var(--soft);margin:0}

/* Chapters: a cover band, then Today, Problems and the fix */
.by .chapter{margin-top:220px}
.by .ch-head{display:grid;grid-template-columns:minmax(0,4.4fr) minmax(0,7.6fr);gap:32px 48px;align-items:center;background:var(--panel);border-radius:24px;padding:48px 40px 48px 56px;overflow:hidden}
.by .ch-text .sol-n{width:40px;height:40px;font-size:16px;margin:0 0 28px}
.by .ch-text h2{font-size:52px;line-height:1.04;letter-spacing:-.035em;margin-bottom:20px}
.by .ch-text>p{font-size:18px;line-height:1.55;color:var(--text);margin:0;max-width:440px}
.by .ch-text .ch-fix{font-size:15px;color:var(--soft);margin-top:20px}
.by .ch-text .ch-fix a{color:var(--strong)}
.by .loc{margin-top:36px;max-width:380px}
.by .loc svg{display:block;width:100%;height:auto}
.by .cover{min-height:200px}
.by .cover svg{display:block;width:100%;height:auto}
.by [data-cover]>svg{animation:cover-in .9s cubic-bezier(.2,.7,.2,1) both}
@keyframes cover-in{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
.by .sub{margin-top:120px;padding-top:28px;border-top:1px solid var(--rule)}
.by .sub>h3{font-size:24px;line-height:1.3;letter-spacing:-.015em;margin-bottom:0}
.by .sub>h3+.prose{margin-top:20px}
.by .sub>.fig:first-of-type,.by .sub>.probs{margin-top:32px}
.by .plan-key{margin-top:18px;font-size:13px}
.by .plan+section{margin-top:120px}

/* Problem cards: every lens from the report on one card */
.by .probs{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}
.by .probs.n3{grid-template-columns:repeat(3,minmax(0,1fr))}
.by .prob{position:relative;background:var(--panel);border-radius:16px;padding:26px 26px 22px}
.by .prob::before{content:'';position:absolute;left:26px;top:0;width:28px;height:2px;border-radius:0 0 2px 2px}
.by .prob.wh::before{background:var(--wh)}.by .prob.pk::before{background:var(--pk)}.by .prob.tr::before{background:var(--tr)}.by .prob.rt::before{background:var(--rt)}
.by .prob h4{font-size:17px;line-height:1.35;font-weight:500;color:var(--strong);margin:0 0 16px;letter-spacing:-.01em}
.by .prob dl{margin:0;display:grid;gap:0}
.by .prob dl>div{display:grid;grid-template-columns:76px minmax(0,1fr);gap:12px;padding:10px 0;border-top:1px solid var(--rule)}
.by .prob dt{font-size:13px;color:var(--muted);padding-top:1px}
.by .prob dd{margin:0;font-size:14.5px;line-height:1.55;color:var(--text)}
.by .prob dd.none{color:var(--muted)}
.by .prob dd b{font-weight:600;color:var(--strong)}

/* Solutions */
.by .sol-head{display:grid;grid-template-columns:56px minmax(0,1fr);gap:0 8px;align-items:start}
.by .sol-n{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;border:1px solid var(--strong);font-size:14px;font-weight:500;color:var(--strong);margin-top:3px;font-variant-numeric:tabular-nums}
.by .sol-n.s{display:inline-grid;width:22px;height:22px;font-size:11px;margin:0 10px 0 0;vertical-align:1px}
.by .sol .stats{margin-left:64px}
.by .fit{margin-top:56px;padding-top:28px;border-top:1px solid var(--rule)}
.by .fit h3{font-size:14px;color:var(--soft);margin-bottom:20px}
.by .fit dl{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px 40px;margin:0}
.by .fit dt{font-size:14px;font-weight:500;color:var(--strong);margin-bottom:4px}
.by .fit dd{margin:0;font-size:14px;line-height:1.55;color:var(--soft)}
.by .notes{list-style:none;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:28px;margin:48px 0 0;padding:0}
.by .notes li{display:grid;grid-template-columns:24px minmax(0,1fr);gap:12px;font-size:14px;line-height:1.55;color:var(--soft)}
.by .notes li>span{display:grid;place-items:center;width:24px;height:24px;border-radius:50%;background:var(--chip);color:var(--strong);font-weight:500;font-size:12px}
.by .notes b{display:block;font-weight:500;color:var(--strong)}
.by .note{display:flex;gap:14px;align-items:flex-start;margin-top:24px;padding:18px 22px;border-radius:14px;border:1px solid var(--rule);font-size:15px;line-height:1.55;color:var(--text);max-width:860px}
.by .note-i{flex:none;display:grid;place-items:center;width:20px;height:20px;border-radius:50%;background:var(--chip);color:var(--strong);font-size:12px;font-weight:600;margin-top:1px}

/* Fig 5: phone and reply flow */
.by .reply{display:grid;grid-template-columns:300px minmax(0,1fr);gap:48px;align-items:center}
.by .phone{width:300px;height:540px;border-radius:40px;background:var(--chat);box-shadow:0 0 0 8px var(--card),0 0 0 9px var(--rule2),0 30px 60px -30px #0000006b;overflow:hidden;display:flex;flex-direction:column;margin:9px}
.by .ph-top{display:flex;align-items:center;gap:10px;padding:30px 16px 12px;background:var(--wa);color:#fff}
.by .ph-av{display:grid;place-items:center;width:32px;height:32px;border-radius:50%;background:#fff;color:#111;font-size:11px;font-weight:700;letter-spacing:-.02em}
.by .ph-name{display:flex;flex-direction:column;font-size:14px;font-weight:500;line-height:1.2}
.by .ph-name small{font-size:11px;font-weight:400;opacity:.8}
.by .ph-chat{flex:1;display:flex;flex-direction:column;gap:8px;padding:14px 12px;overflow:hidden;justify-content:flex-end}
.by .msg{max-width:84%;font-size:13px;line-height:1.45;color:var(--strong);background:var(--bub);padding:7px 10px 6px;border-radius:10px;box-shadow:0 1px 1px #0000001a;animation:msg-in .45s cubic-bezier(.2,.7,.2,1) both}
.by .msg.me{align-self:flex-end;background:var(--me);border-top-right-radius:3px}
.by .msg.biz{align-self:flex-start;border-top-left-radius:3px}
.by .msg small{display:block;text-align:right;font-size:10px;color:var(--soft);margin-top:2px}
.by .msg .btns{display:grid;gap:1px;margin:8px -10px -6px;border-top:1px solid var(--rule)}
.by .msg .btns span{display:block;text-align:center;color:#027eb5;font-size:13px;padding:7px 0;border-bottom:1px solid var(--rule)}
.by .msg .btns span:last-child{border-bottom:0}
.by .msg .btns span.picked{font-weight:600}
.by .day{align-self:center;font-size:11px;color:var(--soft);background:var(--bub);padding:3px 10px;border-radius:7px;box-shadow:0 1px 1px #0000001a;animation:msg-in .45s ease both}
.by .call{display:flex;align-items:center;gap:8px}
.by .call i{display:grid;place-items:center;width:26px;height:26px;border-radius:50%;background:color-mix(in srgb,var(--bad) 15%,transparent);color:var(--bad);font-style:normal}
.by .call i svg{width:14px;height:14px}
@keyframes msg-in{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.by .flow .nd rect{transition:fill .35s ease,stroke .35s ease}
.by .flow .nd text{transition:fill .35s ease}
.by .flow .nd.on rect{fill:var(--strong);stroke:var(--strong)}
.by .flow .nd.on text{fill:var(--card)}
.by .flow .ed{transition:stroke .35s ease,opacity .35s ease}
.by .flow .ed.on{stroke:var(--strong);stroke-width:1.75}
.by .flow .el{transition:fill .35s ease}
.by .flow .el.on{fill:var(--strong);font-weight:500}
.by .reply .plot svg{max-width:750px}

/* Fig 6: route */
.by .route .street{stroke:var(--rule2);stroke-width:1}
.by .route .block{fill:var(--card)}
.by .route .path{fill:none;stroke:var(--strong);stroke-width:2.5;stroke-linejoin:round;stroke-linecap:round}
.by .route .path2{fill:none;stroke:var(--bad);stroke-width:2;stroke-dasharray:6 5;stroke-linejoin:round}
.by .route .stop{transition:opacity .4s ease}
.by .route .van{transition:opacity .3s ease}

/* Fig 7, 8: system and pick path */
.by .wms .fn{cursor:default}
.by .wms .fn rect,.by .wms .fn text,.by .wms .fe{transition:fill .3s ease,stroke .3s ease,opacity .3s ease}
.by .wms.hl .fn:not(.on){opacity:.35}
.by .wms.hl .fe:not(.on){opacity:.12}
.by .wms .fn.on rect{fill:var(--wh);stroke:var(--wh)}
.by .wms .fn.on text{fill:#fff}
.by .pick .rack{fill:var(--card);stroke:var(--rule2)}
.by .pick .slot{stroke:var(--rule);stroke-width:1}
.by .pick .walk{fill:none;stroke:var(--wh);stroke-width:2.5;stroke-linejoin:round;stroke-linecap:round}
.by .pick .item{transition:transform .7s cubic-bezier(.2,.7,.2,1)}

/* Fig 9: truck */
.by .truck .cart{transition:transform .8s cubic-bezier(.3,.7,.2,1),opacity .5s ease}
.by .truck .cart rect.cb{fill:color-mix(in srgb,#c8a26b 70%,var(--card));stroke:color-mix(in srgb,#8a6a3c 70%,var(--card));stroke-width:1}
.by .truck .cart line{stroke:color-mix(in srgb,#8a6a3c 55%,var(--card));stroke-width:1}
.by .truck .base{transition:transform .8s cubic-bezier(.3,.7,.2,1),opacity .5s ease}
.by .truck .wood{fill:color-mix(in srgb,#9c7a4c 80%,var(--card));stroke:color-mix(in srgb,#6b4f2a 80%,var(--card));stroke-width:.75}
.by .truck .sheet{fill:var(--pk);transition:opacity .5s ease .3s}
.by .truck .shell{fill:var(--card);stroke:var(--g0);stroke-width:1.25}
.by .truck .cab{fill:var(--panel);stroke:var(--g0);stroke-width:1.25}
.by .truck .tyre{fill:var(--strong)}
.by .truck .hub{fill:var(--g0)}
.by .vbar{display:flex;height:28px;border-radius:8px;overflow:hidden;gap:2px;margin:28px auto 0;max-width:1000px}
.by .vbar span{display:flex;align-items:center;padding:0 10px;font-size:12px;white-space:nowrap;transition:flex-basis .8s cubic-bezier(.3,.7,.2,1)}
.by .vb-base{flex:0 0 14.43%;background:color-mix(in srgb,#9c7a4c 80%,var(--card));color:#fff}
.by .vb-load{flex:1 1 auto;background:color-mix(in srgb,#c8a26b 55%,var(--card));color:var(--strong);justify-content:flex-end}
.by .truck-slip .vb-base{flex-basis:.9%;padding:0;background:var(--pk)}
.by .truck-slip .vb-base b{position:absolute;opacity:0}
.by .vb-base b{font-weight:500;transition:opacity .3s ease}
.by .vbar-key{display:flex;gap:18px;flex-wrap:wrap;margin:10px auto 0;max-width:1000px;font-size:12px;color:var(--soft)}
.by .vbar-key span{display:inline-flex;align-items:center;gap:6px}
.by .vbar-key em{font-style:normal}
.by .vbar-key i{width:10px;height:10px;border-radius:3px;display:inline-block}
.by .vbar-key .k-base{background:color-mix(in srgb,#9c7a4c 80%,var(--card))}
.by .truck-slip .vbar-key .k-base{background:var(--pk)}
.by .vbar-key .k-load{background:color-mix(in srgb,#c8a26b 55%,var(--card))}
.by .vbar-note{margin-left:auto}

/* Fig 10: the bag */
.by .bag-row{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,7fr);gap:20px;margin-top:56px}
.by .bag-row .fig{margin-top:0;display:flex;flex-direction:column}
.by .bag-row .fig .plot,.by .flip-stage{flex:1}
.by .bag-row .fig-foot{margin-top:auto;padding-top:20px}
.by .flip-stage{display:grid;place-items:center;perspective:1200px;min-height:380px}
.by .flip{display:block;width:210px;height:300px;padding:0;border:0;background:none;cursor:pointer;border-radius:18px}
.by .flip-in{position:relative;display:block;width:100%;height:100%;transform-style:preserve-3d;transition:transform 1.1s cubic-bezier(.5,0,.15,1)}
.by .flip[aria-pressed=true] .flip-in{transform:rotateY(180deg)}
.by .face{position:absolute;inset:0;display:block;backface-visibility:hidden;-webkit-backface-visibility:hidden}
.by .face.f-back{transform:rotateY(180deg)}
.by .pouch,.by .tote{position:absolute;inset:0;display:block;border-radius:14px 14px 18px 18px}
.by .pouch{background:linear-gradient(105deg,#d9dbdd 0%,#f4f5f6 22%,#c5c8cb 44%,#eceef0 62%,#b9bcc0 84%,#dadcde 100%);box-shadow:inset 0 0 0 1px #00000014,inset -10px 0 24px -12px #0000003d,0 24px 40px -24px #0000006b}
.by .seal{position:absolute;left:0;right:0;top:0;height:30px;border-radius:14px 14px 0 0;background:repeating-linear-gradient(90deg,#0000000d 0 2px,transparent 2px 5px);border-bottom:1px solid #0000001f}
.by .tear{position:absolute;left:12px;top:34px;width:9px;height:9px;border-radius:50%;box-shadow:inset 0 1px 2px #00000040}
.by .logo{position:absolute;left:0;right:0;top:46%;text-align:center;font-size:15px;font-weight:600;font-style:italic;letter-spacing:-.01em;color:#3d3f42}
.by .tote{background:linear-gradient(105deg,#1b1c1e 0%,#2d2f32 30%,#141516 58%,#26282b 80%,#161718 100%);box-shadow:inset 0 0 0 1px #ffffff14,0 24px 40px -24px #000000a6}
.by .handle{position:absolute;left:50%;top:26px;width:88px;height:34px;margin-left:-44px;border-radius:16px;background:var(--panel);box-shadow:inset 0 2px 3px #0000004d}
.by .tote-txt{position:absolute;left:0;right:0;top:52%;text-align:center;font-size:12px;letter-spacing:.06em;color:#c9cbce;text-transform:uppercase}
.by .loop .dot{fill:var(--pk)}
.by .loop .dot.k{fill:var(--strong)}

/* Fig 12, 13 */
.by .disp .out rect,.by .disp .out text,.by .disp .de{transition:fill .35s ease,stroke .35s ease,opacity .35s ease}
.by .disp .out:not(.on){opacity:.32}
.by .disp .de{opacity:0}
.by .disp .de.on{opacity:1}
.by .disp .sub{transition:opacity .3s ease}
.by .road-ctl{display:flex;align-items:center;gap:18px;flex-wrap:wrap;margin-bottom:24px;font-size:14px;color:var(--soft)}
.by .road-ctl input{flex:1;min-width:180px;max-width:520px;accent-color:var(--strong)}
.by .road-ctl output{font-size:15px;font-weight:500;color:var(--strong);min-width:64px;font-variant-numeric:tabular-nums}
.by .road .asphalt{fill:#3a3b3d}
.by .road .lane{stroke:#f1f1ec;stroke-width:2;stroke-dasharray:14 10}
.by .road .edge{stroke:#d9d9d2;stroke-width:1.5}
.by .road-out{display:grid;grid-template-columns:repeat(2,minmax(0,240px));gap:32px;margin-top:28px}
.by .road-out b{display:block;font-size:34px;line-height:1.1;font-weight:500;letter-spacing:-.03em;color:var(--strong);font-variant-numeric:tabular-nums}
.by .road-out p{font-size:14px;color:var(--soft);margin:4px 0 0}

/* Fig 14, 15 */
.by .gantt .bar{transition:opacity .3s ease}
.by .gantt .band{fill:var(--strong);opacity:.06}
.by .gantt .now{stroke:var(--strong);stroke-width:1.5}
.by .gantt .knob{fill:var(--strong);cursor:ew-resize}
.by .gantt .hit{fill:transparent;cursor:ew-resize}
.by .gantt.drag,.by .gantt.drag *{cursor:ew-resize}
.by .gantt .bar.off{opacity:.38}
.by .multiples{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.by .multiples>div{background:var(--card);border-radius:14px;padding:20px 20px 14px;box-shadow:0 0 0 1px var(--rule)}
.by .multiples h3{font-size:14px;margin:0 0 2px}
.by .multiples p{font-size:12px;color:var(--soft);margin:0 0 12px;line-height:1.5}
.by .multiples .seg-b{cursor:default;transition:opacity .25s ease}
.by .multiples.hl .seg-b:not(.on){opacity:.35}
.by .itable-wrap{margin-top:48px;overflow-x:auto}
.by .itable{width:100%;border-collapse:collapse;font-size:15px;line-height:1.5;min-width:760px}
.by .itable th,.by .itable td{text-align:left;vertical-align:top;padding:18px 20px 18px 0;border-bottom:1px solid var(--rule)}
.by .itable thead th{font-size:13px;font-weight:400;color:var(--muted);padding-bottom:12px;border-bottom-color:var(--strong)}
.by .itable tbody th{font-weight:500;color:var(--strong);width:30%}
.by .itable td{color:var(--soft)}
.by .itable td b{color:var(--strong);font-weight:500}

/* Next */
.by .next{margin-top:200px}
.by .next-card{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:center;gap:40px;background:#0f0e14;border-radius:20px;overflow:hidden;text-decoration:none;color:#e6e3f2;padding-left:64px}
.by .next-card:hover{color:#e6e3f2}
.by .next-card img{display:block;width:100%;height:auto;transition:transform .6s ease;-webkit-mask-image:linear-gradient(to right,transparent,#000 18%);mask-image:linear-gradient(to right,transparent,#000 18%)}
.by .next-card:hover img{transform:scale(1.03)}
.by .next-text{display:flex;flex-direction:column;padding:64px 0}
.by .next-label{font-size:13px;color:#8f8aa6;margin-bottom:12px}
.by .next-title{font-size:40px;line-height:1.1;font-weight:500;letter-spacing:-.02em;color:#f4f2fb;margin-bottom:12px}
.by .next-line{font-size:17px;color:#bdb8d0;margin-bottom:32px}
.by .next-go{font-size:15px;color:#e6e3f2;text-decoration:underline;text-decoration-color:#5a556e;text-underline-offset:4px;transition:color .2s,text-decoration-color .2s}
.by .next-card:hover .next-go{color:#fff;text-decoration-color:#fff}

/* Reveal: figures and numbers ease in once */
.reveal .by .fig:not(.in):not(.hero-fig),.reveal .by .stats:not(.in),.reveal .by .targets:not(.in),.reveal .by .ch-head:not(.in),.reveal .by .probs:not(.in),.reveal .by .steps:not(.in){opacity:0;transform:translateY(14px)}
.reveal .by .fig,.reveal .by .stats,.reveal .by .targets,.reveal .by .ch-head,.reveal .by .probs,.reveal .by .steps{transition:opacity .8s ease,transform .9s cubic-bezier(.2,.7,.2,1)}

/* Sideways scrolling for wide figures on narrow screens */
.by .hs{overflow:visible}
.by .hs-bar{display:none;position:relative;height:20px;margin:12px 0 0;cursor:pointer;touch-action:none}
.by .hs.wide+.hs-bar{display:block}
.by .hs-bar::before{content:'';position:absolute;left:0;right:0;top:8px;height:4px;border-radius:2px;background:var(--rule2)}
.by .hs-bar i{position:absolute;left:0;top:6px;display:block;height:8px;border-radius:4px;background:var(--soft);transition:background .2s}
.by .hs-bar:active i{background:var(--strong)}

@media(max-width:1100px){
  .by .ch-head{grid-template-columns:minmax(0,1fr);padding:40px 32px}
  .by .probs.n3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .by .steps{grid-template-columns:repeat(3,minmax(0,1fr))}
  .by .steps::before{display:none}
  .by .fit dl{grid-template-columns:repeat(2,minmax(0,1fr))}
  .by .notes{grid-template-columns:repeat(2,minmax(0,1fr))}
  .by .reply{grid-template-columns:minmax(0,1fr);justify-items:center}
  .by .reply .plot{width:100%}
  .by .bag-row{grid-template-columns:minmax(0,1fr)}
  .by .multiples{grid-template-columns:minmax(0,1fr)}
}
@media(max-width:900px){
  .by .waffle{grid-template-columns:minmax(0,1fr);gap:32px}
  .by .waffle .plot{max-width:300px}
}
@media(max-width:700px){
  main.by{padding-inline:20px}
  .by .probs,.by .probs.n3,.by .steps{grid-template-columns:minmax(0,1fr)}
  .by .ch-head{padding:28px 18px;border-radius:18px}
  .by .ch-text h2{font-size:36px}
  .by .chapter{margin-top:140px}
  .by .sub{margin-top:80px}
  .by .prob dl>div{grid-template-columns:64px minmax(0,1fr)}
  .by .back{margin-bottom:56px}
  .by h1{font-size:44px}
  .by .lede{font-size:19px;margin-bottom:40px}
  .by .facts{grid-template-columns:1fr 1fr;gap:20px}
  .by section{margin-top:112px}
  .by h2{font-size:26px}
  .by .prose p{font-size:17px}
  .by .part{margin-top:140px}
  .by .part h2{font-size:40px}
  .by .part p{font-size:18px}
  .by .stats,.by .stats.three{grid-template-columns:1fr 1fr;gap:28px 20px}
  .by .stats.two{grid-template-columns:1fr}
  .by .stat b{font-size:32px}
  .by .targets{grid-template-columns:1fr}
  .by .sol-head{grid-template-columns:1fr}
  .by .sol-n{margin-bottom:16px}
  .by .sol .stats{margin-left:0}
  .by .fit dl,.by .notes{grid-template-columns:1fr;gap:20px}
  .by .fig{padding:20px 14px 18px;border-radius:14px}
  .by .fig-bar{flex-direction:column;align-items:flex-start;margin-bottom:20px}
  .by .hs{overflow-x:auto;overflow-y:hidden;margin:0 -14px;padding:2px 14px;scrollbar-width:none;overscroll-behavior-x:contain}
  .by .hs::-webkit-scrollbar{display:none}
  .by .diagram .hs>svg{min-width:720px}
  .by .hs>.j-in{min-width:980px}
  .by .road-out{grid-template-columns:1fr;gap:16px}
  .by .readout{text-align:left;margin-left:0}
  .by .vbar-note{margin-left:0}
  .by .phone{transform:scale(.92);transform-origin:top center;margin-bottom:-30px}
  .by .next{margin-top:140px}
  .by .next-card{grid-template-columns:1fr;padding-left:0}
  .by .next-text{padding:36px 28px 0}
  .by .next-card img{-webkit-mask-image:linear-gradient(to bottom,transparent,#000 22%);mask-image:linear-gradient(to bottom,transparent,#000 22%)}
}
@media(prefers-reduced-motion:reduce){
  .by *,.by *::before{transition-duration:.01s!important;animation-duration:.01s!important}
}
.by #fig-chain .hs>svg{min-width:0}
@media(max-width:700px){.by #fig-chain .hs>svg{min-width:980px}}