.number-practice{padding-block:65px 40px}
.practice-heading{max-width:850px;margin-bottom:55px}
.practice-heading h1{font:400 clamp(36px,4.7vw,62px)/1.1 var(--serif);letter-spacing:-1.5px;margin:22px 0}
.practice-heading .lead{font-size:22px;line-height:1.6;margin-bottom:20px;max-width:32em}
.practice-heading p{max-width:44em;line-height:1.8}
.practice-tools{display:flex;align-items:center;flex-wrap:wrap;gap:16px 24px;margin-block:26px 18px}
.practice-tools>a:not(.button){font-size:16px;text-decoration:underline;text-underline-offset:4px;min-height:44px;display:inline-flex;align-items:center}
.supporting{font-size:14px;color:var(--muted)}
.practice-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:55px;align-items:start}
.practice-index{position:sticky;top:25px;border-top:1px solid var(--ink);padding-top:22px;display:flex;flex-direction:column;gap:12px}
.practice-index a{font-size:16px;min-height:44px;display:flex;align-items:center;text-decoration:underline;text-underline-offset:5px}
.practice-index .method-link{border-top:1px solid var(--line);padding-top:15px;margin-top:10px}
.exercise-groups{min-width:0}.exercise-group{scroll-margin-top:25px;margin-bottom:55px}
.exercise-group h2,.practice-note h2,.practice-product h2{font:400 34px/1.2 var(--serif);margin-bottom:18px;letter-spacing:-.5px}
.group-intro{font-size:18px;line-height:1.8;margin-bottom:25px;color:var(--muted);max-width:38em}
.number-exercise{scroll-margin-top:25px;padding:30px;margin-block:20px;background:#fff;border:1px solid var(--line);border-radius:4px}
.number-exercise .eyebrow{margin-bottom:16px}.number-exercise fieldset{border:0;padding:0;margin:0;min-width:0}
.number-exercise legend{padding:0;font-size:18px;line-height:1.7;width:100%}
.number-sequence{font:400 clamp(24px,2.5vw,34px)/1.7 var(--serif);font-variant-numeric:tabular-nums;overflow-wrap:anywhere;background:#f4f5ec;padding:22px;margin-block:22px!important;border:1px solid var(--line)}
.number-sequence span{color:#405c27;font-weight:bold}
.number-options{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}
.number-options label{display:flex;align-items:center;gap:9px;min-height:58px;border:1px solid #9aa59b;padding:12px;border-radius:4px;cursor:pointer;font-size:18px}
.number-options label:has(input:checked){background:var(--lime);border-color:var(--ink)}
.number-options input{accent-color:var(--ink);width:18px;height:18px;margin:0;flex:none}
.check-answer{margin-top:20px}.answer-feedback{font-size:18px;line-height:1.7;margin-top:12px!important}.answer-feedback:empty{margin:0!important}
.answer-feedback[data-correct="false"]{color:#8e2d28}
.number-exercise details{border-top:1px solid var(--line);margin-top:20px;padding-top:13px}
.number-exercise summary{font-size:18px;min-height:44px;line-height:1.6;padding-block:6px}
.number-exercise details p{font-size:18px;line-height:1.8;padding-top:14px}
.practice-note{margin:0 0 50px 285px;border-left:3px solid var(--ink);padding-left:25px;max-width:800px}
.practice-note p{font-size:18px;line-height:1.8;margin-top:16px}
.practice-product{display:grid;grid-template-columns:.8fr 1.2fr;gap:45px;padding:35px;border:1px solid var(--line);align-items:center}
.practice-product img{width:100%;height:auto;display:block}.practice-product h2{margin-block:18px}.practice-product p{font-size:18px;line-height:1.8}
.practice-product .product-price{font-size:24px;margin-top:18px}.practice-footer{display:flex;flex-wrap:wrap;gap:15px 30px;border-top:1px solid var(--line);padding-block:25px;margin-top:45px}
.practice-footer a{font-size:14px;min-height:44px;display:flex;align-items:center;text-decoration:underline;text-underline-offset:4px}
@media(max-width:1100px){.practice-layout{grid-template-columns:200px minmax(0,1fr);gap:30px}.practice-note{margin-left:230px}.number-options{grid-template-columns:1fr 1fr}}
@media(max-width:760px){.number-practice{padding-top:38px}.practice-heading h1{letter-spacing:-1px}.practice-heading .lead{font-size:20px}.practice-heading{margin-bottom:32px}.practice-layout{grid-template-columns:1fr;gap:15px}.practice-index{position:static;gap:4px}.practice-index .eyebrow{margin-bottom:12px}.practice-index .method-link{margin-bottom:20px}.number-exercise{padding:24px}.practice-note{margin-left:0}.practice-product{grid-template-columns:1fr;padding:25px;gap:25px}.practice-product img{max-width:450px}.exercise-group{margin-bottom:38px}}
@media(max-width:480px){.practice-heading h1{font-size:36px}.practice-heading .lead{font-size:18px}.practice-tools{gap:12px}.practice-tools .button{width:100%}.number-exercise{padding:20px}.number-options{grid-template-columns:1fr}.number-sequence{font-size:27px;padding:16px}.exercise-group h2,.practice-note h2,.practice-product h2{font-size:30px}.practice-product{padding:22px}.practice-note{padding-left:20px}.practice-footer{gap:4px}}
@media print{
  @page{margin:16mm}
  :root{background:white;color:#111}
  .site-header,.skip,.practice-tools,.practice-index,.check-answer,.answer-feedback,.supporting,.practice-product,.practice-footer{display:none!important}
  .container{width:100%;max-width:none}.number-practice{padding:0}.practice-heading{margin-bottom:20px}.practice-heading h1{font-size:27pt;letter-spacing:0}.practice-heading .lead{font-size:12pt}.practice-heading p,.group-intro{font-size:11pt;line-height:1.5}
  .practice-layout{display:block}.exercise-group{margin-bottom:24px}.exercise-group h2{font-size:19pt}.number-exercise{break-inside:avoid;padding:15px;margin-block:15px;border-color:#777}.number-exercise legend{font-size:12pt;line-height:1.5}.number-sequence{font-size:19pt;background:white;border-color:#777;padding:10px;margin-block:12px!important}.number-options{grid-template-columns:repeat(4,1fr);gap:8px}.number-options label{font-size:11pt;min-height:32px;padding:6px;border-color:#777}.number-options input{display:none}.number-options label:has(input:checked){background:white;border-color:#777}.number-exercise .eyebrow{font-size:9pt}
  .number-exercise details{display:none}.print-answers .number-exercise details{display:block}.print-answers .number-exercise details p{font-size:11pt;line-height:1.5;padding-top:6px}.print-answers summary{font-size:11pt;min-height:0;padding:0;font-weight:bold}.print-answers summary::marker{content:''}.practice-note{margin:20px 0 0;padding-left:15px}.practice-note h2{font-size:17pt}.practice-note p{font-size:11pt;line-height:1.5}
  .practice-heading h1{font-size:24pt;margin:12px 0}.practice-heading .lead{margin-bottom:0}.practice-heading p:not(.lead){display:none}
  .exercise-group{break-before:page;margin-bottom:0}.exercise-group:first-child{break-before:auto}.exercise-group h2{margin-bottom:10px}.group-intro{margin-bottom:12px}
  .number-exercise{padding:10px;margin-block:10px}.number-exercise .eyebrow{margin-bottom:8px}.number-exercise legend{font-size:11pt;line-height:1.4}.number-sequence{line-height:1.3;padding:6px;margin-block:10px!important}
  .number-exercise details{margin-top:8px;padding-top:6px}.print-answers .number-exercise details p{font-size:10pt;line-height:1.4;padding-top:5px}.print-answers summary{font-size:10pt;line-height:1.4}
  .practice-note{break-inside:avoid;margin-top:20px}.practice-note h2{font-size:14pt;margin-bottom:8px}.practice-note p{font-size:10pt;line-height:1.4;margin-top:8px}
}