/* Band Dots for All — shared styles for the static learn pages.
   No framework: these pages are pre-rendered HTML so they index properly and
   load instantly on a phone in a parking lot. */
:root{
  --ink:#12181f; --ink-2:#4a5663; --ink-3:#7c8894;
  --paper:#ffffff; --wash:#f4f7fa; --rule:#dde4ec;
  --blue:#1064b0; --blue-2:#e7f1fb;
  --dot:#0f7d4a;
  --warn:#a8500f; --warn-2:#fdf3e8;
  --max:44rem;
}
*{box-sizing:border-box}
/* .row and .legend li set display, which beats the UA sheet's [hidden]. */
[hidden]{display:none!important}
body{margin:0;background:var(--paper);color:var(--ink);
  font:17px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  -webkit-font-smoothing:antialiased}
a{color:var(--blue)}
img{max-width:100%;height:auto}

.top{border-bottom:1px solid var(--rule);background:var(--paper);
  position:sticky;top:0;z-index:20}
.top .in{max-width:68rem;margin:0 auto;padding:14px 20px;display:flex;
  align-items:center;justify-content:space-between;gap:16px}
.brand{font-weight:800;letter-spacing:.16em;font-size:14px;text-transform:uppercase;
  color:var(--ink);text-decoration:none}
.top nav{display:flex;gap:18px;font-size:14px;flex-wrap:wrap}
.top nav a{text-decoration:none;color:var(--ink-2)}
.top nav a:hover,.top nav a.on{color:var(--blue)}
/* Keep the masthead one row on a phone. When it wrapped to two, the sticky
   offset the calculator pins its field to was wrong and the top of the field
   slid under the header. A nav that scrolls sideways beats a header that
   changes height. */
@media (max-width:620px){
  .top .in{flex-wrap:nowrap;padding:11px 16px;gap:12px}
  .brand{white-space:nowrap;flex:none;font-size:12px}
  .top nav{flex-wrap:nowrap;gap:13px;font-size:13px;overflow-x:auto;
    -webkit-overflow-scrolling:touch;scrollbar-width:none}
  .top nav::-webkit-scrollbar{display:none}
  .top nav a{white-space:nowrap}
}

main{max-width:var(--max);margin:0 auto;padding:0 20px 72px}
.wide{max-width:68rem}
.eyebrow{font-size:12px;letter-spacing:.16em;text-transform:uppercase;
  color:var(--ink-3);font-weight:700;margin:38px 0 10px}
h1{font-size:clamp(29px,5vw,42px);line-height:1.14;letter-spacing:-.02em;margin:0 0 14px;
  text-wrap:balance}
h2{font-size:25px;line-height:1.24;margin:38px 0 12px;letter-spacing:-.01em;text-wrap:balance}
h3{font-size:18px;margin:26px 0 8px}
p{margin:0 0 16px}
.lede{font-size:19px;color:var(--ink-2)}
.dateline{font-size:13px;color:var(--ink-3);margin:0 0 26px;
  padding-bottom:16px;border-bottom:1px solid var(--rule)}

.answer{background:var(--blue-2);border-left:4px solid var(--blue);
  padding:18px 20px;margin:0 0 26px;border-radius:0 8px 8px 0}
.answer p{margin:0 0 10px}.answer p:last-child{margin:0}
.answer b{color:var(--ink)}

.note{background:var(--warn-2);border-left:4px solid var(--warn);
  padding:16px 18px;margin:24px 0;border-radius:0 8px 8px 0;font-size:15.5px}

table{border-collapse:collapse;width:100%;margin:22px 0;font-size:15.5px}
.scroll{overflow-x:auto;-webkit-overflow-scrolling:touch}
th,td{text-align:left;padding:10px 14px;border-bottom:1px solid var(--rule)}
thead th{background:var(--wash);font-size:12px;letter-spacing:.09em;
  text-transform:uppercase;color:var(--ink-3);border-bottom:2px solid var(--rule)}
td.n{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap;font-weight:600}

.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px;margin:22px 0}
.card{border:1px solid var(--rule);border-radius:10px;padding:18px 20px;
  text-decoration:none;color:inherit;display:block;background:var(--paper)}
.card:hover{border-color:var(--blue);box-shadow:0 2px 10px rgba(16,100,176,.08)}
.card h3{margin:0 0 6px;font-size:17px;color:var(--blue)}
.card p{margin:0;font-size:15px;color:var(--ink-2)}

.cta{border:1px solid var(--rule);border-radius:12px;padding:24px;margin:38px 0 0;
  background:var(--wash)}
.cta h2{margin:0 0 8px;font-size:21px}
.cta p{margin:0 0 16px;color:var(--ink-2);font-size:16px}
.btns{display:flex;gap:10px;flex-wrap:wrap}
.btn{display:inline-block;padding:11px 18px;border-radius:8px;text-decoration:none;
  font-weight:600;font-size:15px}
.btn.primary{background:var(--blue);color:#fff}
.btn.ghost{border:1px solid var(--rule);color:var(--ink);background:var(--paper)}

footer.site{border-top:1px solid var(--rule);margin-top:56px;background:var(--wash)}
footer.site .in{max-width:68rem;margin:0 auto;padding:26px 20px;
  font-size:14px;color:var(--ink-3);display:flex;justify-content:space-between;
  gap:16px;flex-wrap:wrap}
footer.site a{color:var(--ink-2)}

/* The calculator is a tool, not an essay, and .wide is this page only: the
   masthead gives up height so the controls and the field start higher. */
.wide .eyebrow{margin-top:24px}
.wide h1{font-size:clamp(26px,3.6vw,34px);margin-bottom:10px}
.wide .lede{font-size:17px;margin-bottom:8px}
.wide .dateline{margin-bottom:16px;padding-bottom:12px}
.wide .answer{padding:14px 18px;margin-bottom:16px;font-size:16px}

/* calculator
   The studio is the page: a narrow column of controls on the left, the field
   drawn on the right. Changing a setting and watching the dots move is the
   whole product demo, and it only lands if both are on screen at once. */
/* Two columns that flow independently, so neither leaves a hole waiting on the
   other: settings then your numbers down the left, the field then the grid
   comparison down the right. */
.studio{display:grid;grid-template-columns:minmax(0,290px) minmax(0,1fr);gap:26px;
  align-items:start;margin:22px 0 0}
/* The field holds still while you work down the settings. 66px clears the
   sticky site header. */
.studio .viz{position:sticky;top:66px;z-index:4;background:var(--paper);
  padding-bottom:6px}
.studio .controls fieldset{margin-bottom:12px}
.studio .out{margin-top:2px}
.studio .stage h2{margin:30px 0 10px;font-size:22px}
.studio .stage table{margin-top:14px}
@media (max-width:900px){
  .studio{grid-template-columns:1fr;gap:16px}
  /* On a phone the field pins to the top of the scroll and the settings run
     under it, so a change is still visible the moment you make it. Both column
     wrappers drop out of the box tree (display:contents) so the figure's sticky
     container is the whole studio — otherwise it would stop travelling the
     instant its own column ended. */
  .studio .side,.studio .stage{display:contents}
  .studio .viz{order:1;top:46px;z-index:5;padding-bottom:8px;
    box-shadow:0 10px 12px -10px rgba(18,24,31,.28)}
  .studio .viz figcaption{display:none}   /* the stats under it say the same thing */
  .studio #legend{order:2}
  .studio #warn{order:3}
  .studio .controls{order:4}
  .studio .out{order:5}
  .studio .stage h2,.studio .stage .scroll,.studio .stage p{order:6}
}
fieldset{border:1px solid var(--rule);border-radius:10px;padding:14px 16px 16px;margin:0 0 16px}
legend{font-size:12px;letter-spacing:.11em;text-transform:uppercase;color:var(--ink-3);
  font-weight:700;padding:0 6px}
label{display:block;font-size:14px;font-weight:600;margin:12px 0 5px}
label:first-of-type{margin-top:0}
select,input[type=number]{width:100%;padding:9px 11px;border:1px solid var(--rule);
  border-radius:7px;font-size:15px;background:var(--paper);color:var(--ink)}
select:focus,input:focus{outline:2px solid var(--blue);outline-offset:1px}
.hint{font-size:13px;color:var(--ink-3);margin:5px 0 0}

/* Secondary controls fold away so the three that matter — step, grid, field —
   are above the fold next to the picture. */
.fold{border:1px solid var(--rule);border-radius:10px;padding:0 16px;margin:0 0 12px}
.fold summary{cursor:pointer;padding:12px 0;font-size:13px;font-weight:700;
  letter-spacing:.06em;text-transform:uppercase;color:var(--ink-2)}
.fold summary:hover{color:var(--blue)}
.fold[open]{padding-bottom:16px}
.fold[open] summary{border-bottom:1px solid var(--rule);margin-bottom:14px}

.out{border:1px solid var(--rule);border-radius:10px;overflow:hidden}
.out header{background:var(--ink);color:#fff;padding:13px 18px;font-size:13px;
  letter-spacing:.1em;text-transform:uppercase;font-weight:700}
.out .body{padding:4px 18px 14px}
.row{display:flex;justify-content:space-between;gap:14px;padding:9px 0;
  border-bottom:1px solid var(--rule);font-size:15px}
.row:last-child{border-bottom:none}
.row span:last-child{font-weight:700;font-variant-numeric:tabular-nums;white-space:nowrap}
.viz{margin:0;padding:0}
.viz svg{width:100%;height:auto;display:block;border-radius:8px}
.viz figcaption{margin-top:8px}

/* The three numbers that move when you move a control, kept beside the picture
   rather than in the table below it. */
.stats{display:flex;flex-wrap:wrap;gap:8px 26px;margin:12px 0 0;
  padding:11px 0;border-top:1px solid var(--rule);border-bottom:1px solid var(--rule)}
.stats div{display:flex;align-items:baseline;gap:7px}
.stats .v{font-size:23px;font-weight:700;letter-spacing:-.02em;color:var(--blue);
  font-variant-numeric:tabular-nums;line-height:1.1}
.stats .k{font-size:13px;color:var(--ink-2)}

.legend{list-style:none;display:flex;gap:8px 20px;flex-wrap:wrap;padding:0;margin:0 0 8px;
  font-size:14px;color:var(--ink-2)}
.legend li{display:flex;align-items:center;gap:7px}
.key{width:13px;height:13px;border-radius:50%;display:inline-block;
  box-shadow:0 0 0 1px rgba(0,0,0,.18)}
.swatches{display:grid;gap:9px}
.swatches label{display:flex;align-items:center;gap:9px;font-weight:400;font-size:14px;margin:0}
.swatches input[type=color]{width:34px;height:26px;padding:1px;border:1px solid var(--rule);
  border-radius:6px;background:var(--paper);cursor:pointer;flex:none}
.linkish{background:none;border:0;padding:0;color:var(--blue);cursor:pointer;
  font-size:13px;text-decoration:underline}

/* On paper nothing is sticky and the controls are not the point. */
@media print{
  .top,.cta,footer.site,.noprint{display:none}
  main{max-width:none}
  .studio{display:block}
  .studio .viz{position:static}
  .studio .controls{display:none}
}

/* community signup */
.join{border:1px solid var(--rule);border-left:4px solid var(--dot);border-radius:10px;
  padding:24px;margin:38px 0 0;background:var(--paper)}
.join h2{margin:0 0 8px;font-size:23px}
.join p{color:var(--ink-2);font-size:16px}
.join form{display:grid;gap:12px;grid-template-columns:1fr 1fr;margin-top:16px}
@media (max-width:600px){.join form{grid-template-columns:1fr}}
.join .full{grid-column:1/-1}
.join input,.join select,.join textarea{width:100%;padding:11px 12px;border:1px solid var(--rule);
  border-radius:8px;font-size:16px;background:var(--paper);color:var(--ink)}
.join button{padding:12px 20px;border:0;border-radius:8px;background:var(--dot);
  color:#fff;font-size:16px;font-weight:600;cursor:pointer}
.join button:disabled{opacity:.65;cursor:default}
.join textarea{font-family:inherit;resize:vertical}
.join button:focus-visible,.join input:focus,.join select:focus,.join textarea:focus{outline:2px solid var(--blue);
  outline-offset:1px}
.join .fine{font-size:13px;color:var(--ink-3);margin:12px 0 0}
.sub-ok{grid-column:1/-1;margin:0;padding:11px 13px;border-radius:8px;
  background:#e8f5ee;color:#0f5c37;font-size:15px}
.sub-err{grid-column:1/-1;margin:0;padding:11px 13px;border-radius:8px;
  background:var(--warn-2);color:var(--warn);font-size:15px}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;
  clip:rect(0,0,0,0);white-space:nowrap;border:0}