/* Behavioral Experiment, behavioralexperiment.com */
:root{
  --teal:#124f54;--teal-deep:#0d3b3f;--sea:#24786e;--sea-tint:#e0ede9;
  --coral:#c24f45;--coral-text:#9e3d33;--coral-tint:#f6e3df;
  --amber:#5c6769;--amber-tint:#eef0ee;
  --ink:#22292b;--ink-soft:#5c6769;--rule:#e3e5e1;
  --sand:#fbfaf7;--sand-deep:#f1f2ee;--cream:#ffffff;
  --max:72rem;--read:44rem;
  --serif:"Source Serif 4",Georgia,"Times New Roman",serif;
  --sans:"Source Sans 3",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
}
@media (prefers-color-scheme:dark){
  :root{--teal:#8ccfc6;--teal-deep:#0d3b3f;--sea:#5fb3a6;--sea-tint:#173436;--coral:#e0776c;--coral-text:#eb9a91;--coral-tint:#3b2320;--amber:#a9b3b3;--amber-tint:#242c2d;--ink:#eceeec;--ink-soft:#a9b3b3;--rule:#2a3335;--sand:#151a1b;--sand-deep:#101415;--cream:#1d2426;}
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--sand);color:var(--ink);font-family:var(--sans);font-size:1.0625rem;line-height:1.6}
a{color:var(--sea);text-underline-offset:.15em}
a:hover{color:var(--coral-text)}
h1,h2,h3,h4{font-family:var(--serif);font-weight:600;line-height:1.15;margin:0 0 .5em;color:var(--ink);letter-spacing:-.005em}
h1{font-size:clamp(2rem,4.5vw,3rem)}
h2{font-size:clamp(1.55rem,3vw,2.05rem);margin-top:2.2em}
h3{font-size:1.25rem;margin-top:1.6em}
p,ul,ol{margin:0 0 1.1em}
li{margin:.3em 0}
strong{font-weight:600}
hr{border:0;border-top:1px solid var(--rule);margin:2.5rem 0}
.wrap{max-width:var(--max);margin:0 auto;padding:0 1.25rem}
.read{max-width:var(--read)}
.skip-link{position:absolute;left:-999px;top:0;background:var(--cream);padding:.5rem 1rem}
.skip-link:focus{left:1rem;z-index:20}

/* header */
.site-header{background:var(--sand);border-bottom:1px solid var(--rule);position:sticky;top:0;z-index:10}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:4rem}
.brand{display:flex;align-items:center;gap:.6rem;text-decoration:none;color:var(--ink);font-family:var(--serif);font-size:1.15rem;font-weight:500}
.brand img,.brand svg{width:30px;height:30px;border-radius:7px}
.nav{display:flex;gap:.15rem;flex-wrap:wrap}
.nav a{text-decoration:none;color:var(--ink-soft);padding:.45rem .7rem;border-radius:999px;font-size:.95rem}
.nav a:hover{color:var(--ink);background:var(--sand-deep)}
.nav a[aria-current=page]{color:var(--cream);background:var(--teal)}
@media (prefers-color-scheme:dark){.nav a[aria-current=page]{color:var(--sand);background:var(--teal)}}
.nav-toggle{display:none;background:none;border:1px solid var(--rule);border-radius:8px;padding:.4rem .7rem;color:var(--ink);font:inherit}
@media (max-width:760px){
  .nav-toggle{display:inline-block}
  .nav{display:none;width:100%;flex-direction:column;padding-bottom:.75rem}
  .nav.open{display:flex}
  .header-inner{flex-wrap:wrap}
}

/* hero */
.hero{padding:3.5rem 0 2.5rem}
.hero h1{max-width:18ch}
.hero .lede{font-size:1.25rem;max-width:34rem;color:var(--ink-soft)}
.actions{display:flex;gap:.75rem;flex-wrap:wrap;margin:1.5rem 0 0}
.btn{display:inline-block;padding:.7rem 1.15rem;border-radius:10px;text-decoration:none;font-weight:600;border:1.5px solid var(--teal);color:var(--teal);background:transparent;font:inherit;font-weight:600;cursor:pointer;line-height:1.3}
.btn.primary{background:var(--teal);color:var(--sand)}
.btn.primary:hover{background:var(--teal-deep);color:var(--sand)}
.btn:hover{color:var(--teal-deep);border-color:var(--teal-deep)}
@media (prefers-color-scheme:dark){.btn.primary{color:#0d1c1d}.btn.primary:hover{background:#a6dcd5;color:#0d1c1d}}
.btn.small{padding:.45rem .85rem;font-size:.95rem}
.btn.coral{border-color:var(--coral);color:var(--coral-text)}
.note{font-size:.95rem;color:var(--ink-soft)}

/* sections */
.section{padding:2.5rem 0}
.section.tint{background:var(--sand-deep)}
.section.teal{background:var(--teal-deep);color:#eef3f1}
.section.teal h2,.section.teal h3{color:#fff}
.section.teal a{color:#a6dcd5}
.section.teal .note{color:#c8d6d3}
.kicker{font-size:.85rem;letter-spacing:.08em;text-transform:uppercase;color:var(--sea);font-weight:600;margin-bottom:.4rem}
.two{display:grid;grid-template-columns:1fr 1fr;gap:2.5rem;align-items:start}
.three{display:grid;grid-template-columns:repeat(3,1fr);gap:1.5rem}
@media (max-width:820px){.two,.three{grid-template-columns:1fr}}

/* worksheet look, used for the worked example and the web worksheet */
.sheet{background:var(--cream);border:1px solid var(--rule);border-radius:14px;padding:1.5rem;box-shadow:0 1px 0 rgba(0,0,0,.03)}
.sheet h3{margin-top:0;font-size:1.1rem}
.field{margin:0 0 1.1rem}
.field .label{font-size:.8rem;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-soft);font-weight:600;margin-bottom:.2rem}
.field .value{margin:0}
.pill{display:inline-block;font-weight:700;font-size:.85rem;padding:.15rem .6rem;border-radius:999px;color:#fff;background:var(--sea);font-variant-numeric:tabular-nums}
.pill.warm{background:var(--coral)}
.pill.mid{background:var(--sea)}
.rule-row{border-top:1px dashed var(--rule);margin:1rem 0}

/* steps */
.steps{counter-reset:step;list-style:none;padding:0;margin:0}
.steps li{counter-increment:step;position:relative;padding-left:3rem;margin:0 0 1.3rem}
.steps li::before{content:counter(step);position:absolute;left:0;top:.05rem;width:2.1rem;height:2.1rem;border-radius:50%;background:var(--teal);color:var(--sand);font-family:var(--serif);font-weight:600;display:flex;align-items:center;justify-content:center}
@media (prefers-color-scheme:dark){.steps li::before{color:#0d1c1d}}
.steps li strong{display:block;font-family:var(--serif);font-weight:500;font-size:1.15rem;margin-bottom:.15rem}

/* callouts */
.callout{border-left:4px solid var(--sea);background:var(--sea-tint);padding:.9rem 1.1rem;border-radius:0 10px 10px 0;margin:1.4rem 0}
.callout.caution{border-color:var(--coral);background:var(--coral-tint)}
.callout.example{border-color:var(--ink-soft);background:var(--sand-deep)}
.callout p:last-child{margin-bottom:0}

/* article */
.article h2{font-size:1.6rem}
.refs{list-style:none;padding:0;font-size:.95rem}
.refs li{padding-left:2rem;text-indent:-2rem;margin:.6em 0;color:var(--ink-soft)}
.refs li a{word-break:break-all}
.article-list{list-style:none;padding:0;margin:0}
.article-list li{border-top:1px solid var(--rule);padding:1.1rem 0}
.article-list li:last-child{border-bottom:1px solid var(--rule)}
.article-list a{font-family:var(--serif);font-size:1.3rem;text-decoration:none;color:var(--ink)}
.article-list a:hover{color:var(--sea)}
.article-list p{margin:.25rem 0 0;color:var(--ink-soft)}
.crumbs{font-size:.9rem;color:var(--ink-soft);margin:1.5rem 0 0}
.crumbs a{color:var(--ink-soft)}
.meta{color:var(--ink-soft);font-size:.95rem}

/* screenshots */
.shots{display:grid;grid-template-columns:repeat(3,1fr);gap:1.25rem;margin:1.5rem 0}
.shots figure{margin:0}
.shots img{width:100%;height:auto;border-radius:22px;border:1px solid var(--rule);display:block}
.shots figcaption{font-size:.9rem;color:var(--ink-soft);margin-top:.5rem}
@media (max-width:820px){.shots{grid-template-columns:1fr 1fr}}
@media (max-width:520px){.shots{grid-template-columns:1fr}}
.badge img{height:44px;width:auto}

/* faq */
details{border-top:1px solid var(--rule);padding:.6rem 0}
details:last-of-type{border-bottom:1px solid var(--rule)}
summary{cursor:pointer;font-weight:600;padding:.4rem 0;list-style:none}
summary::-webkit-details-marker{display:none}
summary::before{content:"+";display:inline-block;width:1.4rem;color:var(--sea);font-weight:700}
details[open] summary::before{content:"\2212"}
details p{margin:.4rem 0 .6rem 1.4rem}

/* footer */
.site-footer{border-top:1px solid var(--rule);margin-top:3rem;padding:2.5rem 0 3rem;font-size:.92rem;color:var(--ink-soft)}
.site-footer .cols{display:grid;grid-template-columns:2fr 1fr 1fr;gap:2rem}
@media (max-width:760px){.site-footer .cols{grid-template-columns:1fr}}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin:.3em 0}
.site-footer a{color:var(--ink-soft)}
.disclaimer{max-width:var(--read);margin-top:1.5rem}

/* forms (worksheet, ladder) */
.form label{display:block;font-weight:600;margin:1rem 0 .3rem}
.form .hint{font-weight:400;color:var(--ink-soft);font-size:.95rem;display:block;margin:0 0 .4rem}
.form textarea,.form input[type=text],.form input[type=date],.form input[type=time],.form select{width:100%;font:inherit;padding:.6rem .7rem;border:1px solid var(--rule);border-radius:8px;background:var(--cream);color:var(--ink)}
.form textarea{min-height:5.5rem;resize:vertical}
.form input[type=range]{width:100%;accent-color:var(--sea)}
.range-row{display:flex;align-items:center;gap:.75rem}
.range-row output{min-width:3.2rem;text-align:center}
.chips{display:flex;flex-wrap:wrap;gap:.5rem;margin:.4rem 0}
.chip{border:1px solid var(--rule);background:var(--cream);border-radius:999px;padding:.3rem .8rem;font:inherit;font-size:.95rem;color:var(--ink);cursor:pointer}
.chip[aria-pressed=true]{background:var(--coral);border-color:var(--coral);color:#fff}
.choices{display:flex;gap:.5rem;flex-wrap:wrap}
.choices button{font:inherit;border:1px solid var(--rule);background:var(--cream);color:var(--ink);border-radius:8px;padding:.5rem .8rem;cursor:pointer}
.choices button[aria-pressed=true]{background:var(--teal);border-color:var(--teal);color:var(--sand)}
.toolbar{display:flex;gap:.6rem;flex-wrap:wrap;margin:1.5rem 0}
.status{font-size:.9rem;color:var(--ink-soft)}
.ladder-list{list-style:none;padding:0;margin:1rem 0}
.ladder-list li{display:grid;grid-template-columns:auto 1fr auto auto;gap:.75rem;align-items:center;padding:.6rem 0;border-top:1px solid var(--rule)}
.ladder-list li:last-child{border-bottom:1px solid var(--rule)}
.ladder-list .num{width:2rem;height:2rem;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:700;color:#fff;font-size:.85rem}
.ladder-list button{font:inherit;background:none;border:1px solid var(--rule);border-radius:6px;color:var(--ink-soft);padding:.2rem .5rem;cursor:pointer}
.ladder-list .done{text-decoration:line-through;color:var(--ink-soft)}

/* print: the web worksheet prints clean */
@media print{
  .site-header,.site-footer,.toolbar,.nav,.no-print,.hero .lede,.status,.form .hint{display:none!important}
  body{background:#fff;color:#000;font-size:10.5pt;line-height:1.35}
  .hero{padding:0 0 .5rem}
  h1{font-size:18pt}
  .sheet{border:1px solid #999;box-shadow:none;break-inside:auto;padding:.8rem 1rem;margin-top:.6rem!important;border-radius:6px}
  .sheet h3{break-after:avoid}
  .form label{margin:.5rem 0 .15rem;break-after:avoid}
  .form textarea,.form input{border:1px solid #999;background:#fff;min-height:0;overflow:hidden;resize:none}
  .form textarea::placeholder,.form input::placeholder{color:transparent}
  .form input[type=range]{display:none}
  .range-row output{border:1px solid #999;color:#000!important;background:#fff!important}
  .chips{display:none}
  .choices button{color:#000;background:#fff;border-color:#999}
  .choices button[aria-pressed=true]{background:#000;color:#fff;border-color:#000}
  a{color:#000;text-decoration:none}
}