/* The mathematics chapter: a paper workbench within the shared visual system. */
.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}
.math-intro{display:grid;grid-template-columns:1fr 1fr;align-items:end;gap:70px;margin-bottom:24px}
.math-intro h2{font-size:42px;line-height:1.14;margin-top:15px}
.math-intro>p{font-size:13px;line-height:1.9;color:var(--muted);max-width:440px;justify-self:end}
.mathematics-workbench{padding-top:20px;padding-bottom:35px}
.lesson-shell{border:1px solid var(--line);background:var(--paper-light)}
.lesson-toolbar{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:17px 24px;border-bottom:1px solid var(--line)}
.lesson-degree{display:flex;gap:4px;flex-wrap:wrap}
.lesson-degree button{border:0;background:transparent;color:var(--muted);font-size:12px;padding:9px 14px;display:flex;align-items:baseline;gap:16px}
.lesson-degree button>span{font-family:var(--serif);font-size:19px;color:var(--jade)}
.lesson-degree button.active{background:var(--forest);color:var(--paper-light)}
.lesson-degree button.active>span{color:#ddd9bf}
.lesson-count{font-size:10px;text-transform:uppercase;letter-spacing:1px;color:var(--muted);text-align:right}
.lesson-stagebar{display:flex;justify-content:space-between;align-items:stretch;gap:20px;padding:24px 28px 18px}
.lesson-passes{display:flex;gap:20px;flex-wrap:wrap}
.lesson-passes button{display:block;border:0;border-bottom:1px solid var(--line);background:transparent;font-size:11px;text-align:left;color:var(--muted);padding:0 0 9px;min-width:140px}
.lesson-passes button>span{display:block;text-transform:uppercase;letter-spacing:1.7px;font-size:9px;margin-bottom:4px}
.lesson-passes button.active{border-bottom:2px solid var(--red);color:var(--red)}
.lesson-arrows{display:flex;gap:7px;align-items:center}
.lesson-arrows button{border:1px solid var(--line);background:transparent;width:35px;height:35px;color:var(--jade);font-size:17px}
.lesson-stage-summary{margin:0 28px 20px;font-size:12px;line-height:1.8;color:var(--muted)}
.lesson-stage-summary strong{color:var(--ink);font-weight:500}
.lesson-rows{border-top:1px solid var(--line);padding:0 28px}
.lesson-row{display:grid;grid-template-columns:145px minmax(0,1fr);gap:22px;padding:24px 0;border-bottom:1px solid var(--line)}
.lesson-row:last-child{border-bottom:0}
.lesson-row-label>span{color:var(--red);font-size:10px;letter-spacing:1.5px;display:block;margin-bottom:5px}
.lesson-row-label strong{display:block;font-size:12px;font-weight:500}
.lesson-row-label small{display:block;font-size:10px;line-height:1.7;margin-top:4px;color:var(--muted)}
.lesson-values{display:grid;grid-template-columns:repeat(auto-fit,minmax(58px,1fr));gap:7px;align-content:start}
.lesson-value{min-height:58px;padding:6px 7px;text-align:center;border:1px solid #deded2;background:#f2f2e8;font-family:var(--serif);font-size:21px;font-variant-numeric:tabular-nums;color:var(--ink);position:relative}
.lesson-position{display:block;color:#737d70;font-family:var(--sans);font-size:9px;line-height:1.2;margin-bottom:5px}
.lesson-removed{color:#ac6254;background:#f2e8de;border-color:#e5cbbf}
.lesson-removed .lesson-position{color:#9c5d50}
.lesson-removed s{text-decoration-thickness:1px;text-decoration-color:var(--red)}
.lesson-contributing{border-color:#93a990;background:#dfe8d6}
.lesson-total{background:#e7ebdf;border-color:#c6d1bc}
.lesson-total:hover{border-color:var(--jade);background:#d8e2ce}
.lesson-total strong{font-weight:400}
.lesson-total.is-selected{background:var(--forest);color:var(--paper-light);border-color:var(--forest)}
.lesson-total.is-selected .lesson-position{color:#c1cdbb}
.lesson-explanation{background:#e8ecdf;border-top:1px solid var(--line);padding:20px 28px}
.lesson-explanation>span{font-size:9px;text-transform:uppercase;letter-spacing:1.7px;color:var(--jade)}
.lesson-explanation p{font-family:var(--serif);font-size:22px;line-height:1.6;margin:7px 0;overflow-wrap:anywhere}
.lesson-explanation p strong{color:var(--red);font-weight:400;white-space:nowrap}
.lesson-explanation>small{font-size:10px;line-height:1.7;display:block;color:var(--muted)}
.lesson-final{display:flex;justify-content:space-between;align-items:center;gap:25px;padding:24px 28px;border-top:1px solid var(--line)}
.lesson-final .eyebrow{font-size:9px;letter-spacing:1.8px}
.lesson-final>div>strong{font-family:var(--serif);font-size:22px;font-weight:400;display:block;margin-top:8px;line-height:1.3}
.lesson-results{display:flex;gap:24px}
.lesson-results>span{text-align:center;min-width:28px}
.lesson-results small{display:block;font-family:var(--sans);font-size:10px;color:var(--muted)}
.lesson-results strong{display:block;font-family:var(--serif);font-size:25px;font-weight:400;color:var(--jade);font-variant-numeric:tabular-nums}
.math-page-intro{border-top:1px solid var(--line);padding-top:24px;margin-top:35px;color:var(--muted);font-size:12px}
.math-equation{border-left:2px solid var(--jade);background:#e7ebdf;padding:24px 26px;margin:24px 0}
.math-equation>span{font-family:var(--serif);font-size:27px;line-height:1.6;color:var(--forest);display:block;overflow-wrap:anywhere}
.math-equation>small{display:block;color:var(--muted);font-size:11px;line-height:1.8;margin-top:10px}
.math-equation-long>span{font-size:24px}
.math-note{border-left:2px solid var(--red);padding:18px 23px;background:#eee5da;margin:24px 0}
.math-note>strong{font-size:12px;text-transform:uppercase;letter-spacing:.6px}
.article-section .math-note>p{font-size:13px;line-height:1.8;margin-top:8px}
.math-table-wrap{margin:24px 0;border:1px solid var(--line)}
.article-section .math-table{margin:0;min-width:480px}
.math-table caption{text-align:left;background:#efefe4;padding:12px 15px;font-size:10px;letter-spacing:.7px;color:var(--muted)}
.article-section .math-table th{white-space:nowrap}
.article-section .math-table tbody th{background:transparent;font-size:10px}
.article-section .math-table tbody td:last-child{font-variant-numeric:tabular-nums;color:var(--ink);font-size:12px;line-height:1.9}
.article-section .math-table .worked-sum{background:#e8ede0}
.article-section .math-table .worked-sum th{color:var(--forest)}
.proof-roadmap{list-style:none;counter-reset:proof-step;padding-left:0!important}
.proof-roadmap>li{counter-increment:proof-step;position:relative;padding:0 0 17px 42px;border-bottom:1px solid var(--line);margin-bottom:18px}
.proof-roadmap>li:before{content:counter(proof-step,decimal-leading-zero);position:absolute;left:0;top:3px;color:var(--red);font-size:11px;font-weight:500;letter-spacing:1px}
.math-download-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px;margin:24px 0}
.article-section a.math-download{text-decoration:none;display:block;border:1px solid var(--line);padding:20px;background:var(--paper-light);color:var(--ink)}
.math-download>span{display:block;font-size:9px;letter-spacing:1.7px;text-transform:uppercase;color:var(--jade);margin-bottom:8px}
.math-download>strong{font-family:var(--serif);font-weight:400;font-size:22px;line-height:1.25;display:block}
.math-download>small{display:block;color:var(--muted);font-size:11px;line-height:1.7;margin-top:10px}
.article-section a.math-download:hover{border-color:var(--jade);background:#e9edde}
@media(max-width:1000px){.lesson-final{align-items:flex-start;flex-direction:column}.lesson-results{width:100%;justify-content:space-between}.math-intro{gap:35px}.math-intro h2{font-size:36px}}
@media(max-width:760px){.mathematics-workbench{padding-top:5px;padding-bottom:15px}.math-intro{grid-template-columns:1fr;gap:16px}.math-intro h2{font-size:34px}.math-intro>p{max-width:none;justify-self:start;font-size:12px}.lesson-toolbar{padding:12px 15px;flex-direction:column;align-items:flex-start;gap:11px}.lesson-degree{gap:3px}.lesson-degree button{font-size:10px;padding:7px 10px;gap:10px}.lesson-degree button>span{font-size:16px}.lesson-count{font-size:9px;letter-spacing:.7px}.lesson-stagebar{padding:18px 16px 14px;gap:12px}.lesson-passes{gap:12px;flex:1}.lesson-passes button{font-size:10px;min-width:105px;flex:1}.lesson-arrows{align-self:flex-start;gap:4px}.lesson-arrows button{width:29px;height:29px}.lesson-stage-summary{margin:0 16px 16px;font-size:11px}.lesson-rows{padding:0 16px}.lesson-row{grid-template-columns:1fr;gap:13px;padding:18px 0}.lesson-row-label{display:flex;align-items:baseline;flex-wrap:wrap;gap:9px}.lesson-row-label>span{margin:0}.lesson-row-label>small{margin:0 0 0 auto;font-size:9px}.lesson-values{grid-template-columns:repeat(auto-fit,minmax(48px,1fr));gap:5px}.lesson-value{font-size:18px;min-height:51px;padding:5px}.lesson-position{font-size:8px}.lesson-explanation{padding:16px}.lesson-explanation p{font-size:20px}.lesson-final{padding:20px 16px;gap:18px}.lesson-final>div>strong{font-size:21px}.lesson-results{gap:10px}.lesson-results strong{font-size:22px}.math-equation{padding:17px 19px}.math-equation>span{font-size:23px}.math-equation-long>span{font-size:20px}.math-equation>small{font-size:10px}.math-note{padding:16px 19px}.proof-roadmap>li{padding-left:32px}.math-download-grid{grid-template-columns:1fr}}
@media print{.lesson-toolbar,.lesson-stagebar,.lesson-stage-summary{display:none}.lesson-row{grid-template-columns:120px minmax(0,1fr);gap:15px}.lesson-value{font-size:16px}.lesson-rows{padding:0 15px}.lesson-explanation{padding:15px}.lesson-final{padding:15px}.math-equation,.math-note,.math-download-grid{break-inside:avoid}.math-table-wrap{overflow:visible}.article-section .math-table{min-width:0}.math-intro h2{font-size:30px}}