:root{
  --math-purple:#6d28d9;
  --math-purple-dark:#4c1d95;
  --math-purple-soft:#f5f3ff;
  --math-green:#159447;
  --math-green-dark:#116a35;
  --math-green-soft:#eefbf2;
  --math-ink:#263247;
  --math-line:#ddd6fe;
  --math-white:#fff;
}
.math-page{max-width:1180px;margin:0 auto;padding:22px 16px 48px;color:var(--math-ink)}
.math-hero{position:relative;overflow:hidden;background:linear-gradient(135deg,var(--math-purple-dark) 0%,var(--math-purple) 55%,#7c3aed 100%);color:#fff;border-radius:28px;padding:34px 32px;box-shadow:0 18px 45px rgba(76,29,149,.22);margin:22px 0 24px}
.math-hero:after{content:"";position:absolute;right:-80px;bottom:-95px;width:270px;height:270px;border-radius:50%;background:rgba(21,148,71,.55);box-shadow:-85px -85px 0 rgba(255,255,255,.07)}
.math-hero>*{position:relative;z-index:1}.math-kicker{display:inline-flex;align-items:center;gap:8px;background:var(--math-green);border:1px solid rgba(255,255,255,.28);border-radius:999px;padding:7px 13px;font-weight:900;letter-spacing:.02em}
.math-hero h2{color:#fff;font-size:clamp(2rem,5vw,3.35rem);line-height:1.05;margin:15px 0 12px;max-width:850px}.math-hero p{font-size:1.08rem;line-height:1.72;max-width:920px;color:#f8f7ff}
.math-stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin-top:22px;max-width:760px}.math-stat{background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.2);border-radius:16px;padding:13px 15px;backdrop-filter:blur(3px)}.math-stat strong{display:block;font-size:1.28rem;color:#fff}.math-stat span{font-size:.9rem;color:#f2ecff}
.math-intro{background:#fff;border:1px solid #e5e7eb;border-left:7px solid var(--math-green);border-radius:20px;padding:20px 22px;margin:0 0 26px;box-shadow:0 9px 25px rgba(15,23,42,.06)}.math-intro h2{color:var(--math-purple-dark);margin:.05rem 0 .55rem}.math-intro p{line-height:1.7;margin:.5rem 0}
.math-area{margin:28px 0}.math-area-head{display:flex;align-items:center;gap:14px;background:linear-gradient(90deg,var(--math-purple-dark),var(--math-purple));color:#fff;border-radius:20px;padding:16px 19px;box-shadow:0 10px 24px rgba(76,29,149,.14)}.math-area-no{flex:0 0 auto;width:42px;height:42px;display:grid;place-items:center;border-radius:13px;background:var(--math-green);font-weight:950;font-size:1.05rem}.math-area-head h2{color:#fff;margin:0;font-size:1.35rem}.math-area-head p{margin:.25rem 0 0;color:#efeaff;line-height:1.45}
.math-chapters{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px;margin-top:13px}.math-chapter{background:#fff;border:1px solid #e5e7eb;border-top:5px solid var(--math-green);border-radius:18px;padding:15px 16px;box-shadow:0 7px 20px rgba(15,23,42,.05);transition:transform .18s ease,box-shadow .18s ease}.math-chapter:hover{transform:translateY(-2px);box-shadow:0 11px 25px rgba(76,29,149,.10)}.math-chapter-top{display:flex;align-items:flex-start;gap:11px}.math-num{flex:0 0 auto;min-width:42px;height:42px;padding:0 7px;display:grid;place-items:center;background:var(--math-purple-soft);border:1px solid var(--math-line);color:var(--math-purple-dark);font-weight:950;border-radius:12px}.math-chapter h3{margin:.05rem 0 .35rem;color:var(--math-purple-dark);font-size:1.05rem;line-height:1.3}.math-chapter p{margin:.35rem 0 0;line-height:1.55;color:#536174;font-size:.94rem}.math-tag{display:inline-block;margin-top:8px;background:var(--math-green-soft);border:1px solid #bde9ca;color:var(--math-green-dark);padding:4px 8px;border-radius:999px;font-size:.8rem;font-weight:900}.math-coming{display:inline-block;margin-left:6px;background:#f3f4f6;color:#596273;padding:4px 8px;border-radius:999px;font-size:.78rem;font-weight:800}
.math-source-note{margin-top:30px;background:linear-gradient(135deg,var(--math-green-soft),#fff);border:1px solid #ccefd6;border-left:7px solid var(--math-purple);border-radius:19px;padding:18px 20px}.math-source-note strong{color:var(--math-purple-dark)}
@media(max-width:760px){.math-page{padding:14px 10px 34px}.math-hero{padding:23px 19px;border-radius:21px}.math-hero h2{font-size:2.05rem}.math-stats{grid-template-columns:1fr}.math-chapters{grid-template-columns:1fr}.math-area-head{align-items:flex-start;border-radius:17px;padding:14px}.math-area-head h2{font-size:1.18rem}.math-intro{padding:17px}.math-chapter{padding:14px}}


/* Chapter notes */
.math-notes-page{width:100%;max-width:1100px;min-width:0;box-sizing:border-box;margin:0 auto;padding:18px 16px 48px;color:var(--math-ink);line-height:1.68}
.math-chapter-hero{position:relative;overflow:hidden;background:linear-gradient(135deg,var(--math-purple-dark),var(--math-purple) 58%,#7c3aed);color:#fff;border-radius:26px;padding:30px 30px 27px;margin:18px 0 22px;box-shadow:0 16px 38px rgba(76,29,149,.2)}
.math-chapter-hero:after{content:"";position:absolute;width:250px;height:250px;border-radius:50%;right:-80px;bottom:-115px;background:rgba(21,148,71,.7)}
.math-chapter-hero>*{position:relative;z-index:1}.math-chapter-label{margin-top:15px;font-weight:900;color:#d9fbe5;letter-spacing:.04em;text-transform:uppercase}.math-chapter-hero h2{font-size:clamp(2.3rem,6vw,4rem);color:#fff;margin:.15rem 0 .55rem;line-height:1}.math-chapter-hero p{max-width:820px;color:#f7f4ff;font-size:1.06rem}.math-subtopic-pills{display:flex;gap:8px;flex-wrap:wrap;margin-top:18px}.math-subtopic-pills a{color:#fff;text-decoration:none;background:rgba(255,255,255,.13);border:1px solid rgba(255,255,255,.28);padding:7px 11px;border-radius:999px;font-weight:800;font-size:.88rem}.math-subtopic-pills a:hover{background:var(--math-green)}
.math-learning-box{display:grid;grid-template-columns:minmax(0,2fr) minmax(240px,1fr);gap:18px;background:#fff;border:1px solid #e5e7eb;border-left:7px solid var(--math-green);border-radius:18px;padding:19px 21px;box-shadow:0 7px 22px rgba(15,23,42,.05);margin-bottom:18px}.math-learning-box h2{color:var(--math-purple-dark);margin:.05rem 0 .45rem;font-size:1.3rem}.math-learning-box ul{margin:.5rem 0 .2rem;padding-left:1.25rem}.math-learning-box li{margin:.32rem 0}.math-learning-box aside{background:var(--math-purple-soft);border:1px solid var(--math-line);border-radius:14px;padding:14px 15px}.math-learning-box aside strong{color:var(--math-purple-dark);font-size:1.02rem}.math-learning-box aside p{margin:.45rem 0 0}
.math-page-toc{background:var(--math-green-soft);border:1px solid #bde9ca;border-radius:20px;padding:16px 18px;margin:18px 0 26px}.math-page-toc strong{display:block;color:var(--math-green-dark);margin-bottom:12px;font-size:1.06rem}.math-page-toc ol{list-style:none;counter-reset:subtopics;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:0;padding:0}.math-page-toc li{counter-increment:subtopics}.math-page-toc li a{display:flex;align-items:flex-start;gap:10px;height:100%;min-height:84px;background:#fff;border:1px solid #ddd6fe;border-top:5px solid var(--math-purple);border-radius:16px;padding:14px 14px 13px;text-decoration:none;color:var(--math-purple-dark);font-weight:900;line-height:1.35;box-shadow:0 6px 18px rgba(15,23,42,.05);transition:transform .18s ease, box-shadow .18s ease, border-color .18s ease}.math-page-toc li a::before{content:counter(subtopics);flex:0 0 auto;display:grid;place-items:center;width:30px;height:30px;border-radius:9px;background:var(--math-purple-soft);border:1px solid var(--math-line);color:var(--math-purple-dark);font-size:.92rem;font-weight:950}.math-page-toc li a:hover{transform:translateY(-2px);box-shadow:0 12px 25px rgba(76,29,149,.12);border-color:#c9c0fb}.math-page-toc li:nth-child(even) a{border-top-color:var(--math-green)}
.math-topic{scroll-margin-top:18px;background:#fff;border:1px solid #e5e7eb;border-radius:22px;padding:22px;margin:22px 0;box-shadow:0 7px 25px rgba(15,23,42,.05)}.math-topic-heading{display:flex;gap:13px;align-items:center;border-bottom:2px solid #eee9ff;padding-bottom:12px;margin-bottom:16px}.math-topic-heading>span{width:44px;height:44px;flex:0 0 44px;display:grid;place-items:center;border-radius:13px;background:var(--math-green);color:#fff;font-size:1.1rem;font-weight:950}.math-topic-heading p{margin:0;color:var(--math-green-dark);font-size:.8rem;font-weight:900;text-transform:uppercase;letter-spacing:.06em}.math-topic-heading h2{margin:0;color:var(--math-purple-dark);font-size:1.65rem}
.math-concept-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:17px 0}.math-concept-card{border:1px solid #e7e1ff;border-top:4px solid var(--math-purple);background:linear-gradient(180deg,#fff,var(--math-purple-soft));border-radius:15px;padding:14px}.math-concept-card h3{color:var(--math-purple-dark);margin:.05rem 0 .35rem;font-size:1.05rem}.math-concept-card p{margin:.35rem 0}.math-formula{font-size:1.08rem;font-weight:800;color:var(--math-green-dark);margin:.45rem 0}
.math-key-box,.math-method-box,.math-exam-tip,.math-revision-box{border-radius:17px;padding:16px 18px;margin:18px 0}.math-key-box{background:#faf9ff;border:1px solid var(--math-line);border-left:6px solid var(--math-purple)}.math-key-box h3,.math-method-box h3{color:var(--math-purple-dark);margin:.05rem 0 .6rem}.math-method-box{background:var(--math-green-soft);border:1px solid #c7edd2;border-left:6px solid var(--math-green)}.math-method-columns,.math-rule-row{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.math-method-columns>div,.math-rule-row>div{background:rgba(255,255,255,.72);border-radius:12px;padding:12px 14px}.math-method-columns ol,.math-rule-row ul{margin:.5rem 0 .1rem;padding-left:1.25rem}.math-note{margin:.75rem 0 0;font-weight:800;color:var(--math-green-dark)}.math-exam-tip{background:#fff8eb;border:1px solid #f2d6a0;border-left:6px solid #e09b27}.math-exam-tip>strong{color:#7c4b00}.math-exam-tip ul{margin:.5rem 0 .1rem;padding-left:1.2rem}
.math-table{width:100%;border-collapse:collapse;margin:10px 0;background:#fff}.math-table th,.math-table td{border:1px solid #dcd6ef;padding:9px 10px;text-align:left;vertical-align:top}.math-table th{background:var(--math-purple-dark);color:#fff}.math-mini-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin:12px 0}.math-mini-grid>div{text-align:center;background:var(--math-green-soft);border:1px solid #c7edd2;border-radius:12px;padding:8px}
.worked-example{border:1px solid #d7dbe3;border-radius:17px;margin:18px 0;overflow:hidden;background:#f3f4f6;box-shadow:0 4px 12px rgba(15,23,42,.04)}.worked-example .worked-label{padding:8px 14px;font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;font-weight:950;color:#fff}.worked-example.easy .worked-label{background:var(--math-green)}.worked-example.medium .worked-label{background:var(--math-purple)}.worked-example.exam .worked-label{background:var(--math-purple-dark)}.worked-example>h3,.worked-example>p{margin-left:16px;margin-right:16px}.worked-example>h3{color:var(--math-purple-dark);margin-top:13px}.worked-solution{background:#eef1f5;border-top:1px dashed #c8d0da;margin-top:12px;padding:13px 16px}.worked-solution p{margin:.4rem 0}.worked-solution mjx-container[display="true"]{margin:.65em 0!important}.math-notes-page mjx-container[display="true"]{max-width:100%;overflow-x:auto;overflow-y:hidden}
.math-definition-pair{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px;margin:15px 0}.math-definition-pair article{border-radius:15px;padding:15px;border:1px solid #ddd6fe;background:var(--math-purple-soft)}.math-definition-pair article:nth-child(2){background:var(--math-green-soft);border-color:#c6ecd2}.math-definition-pair h3{margin:.05rem 0 .45rem;color:var(--math-purple-dark)}
.math-practice{background:#f8fafc;border:1px solid #e2e8f0;border-radius:22px;padding:22px;margin:24px 0}.math-practice-intro{max-width:870px}.practice-level{margin:24px 0 10px;color:var(--math-purple-dark);border-bottom:2px solid #ddd6fe;padding-bottom:7px}.question-card{background:#fff;border:1px solid #dfe3ea;border-left:5px solid var(--math-green);border-radius:15px;padding:15px;margin:12px 0;box-shadow:0 3px 11px rgba(15,23,42,.04)}.question-card.exam-q{border-left-color:var(--math-purple)}.q-head{display:flex;align-items:center;gap:9px;flex-wrap:wrap}.q-head>span{width:30px;height:30px;display:grid;place-items:center;border-radius:9px;background:var(--math-purple-soft);color:var(--math-purple-dark);font-weight:950}.q-head strong{color:var(--math-purple-dark);font-size:1.02rem}.q-head em{margin-left:auto;color:#64748b;font-style:normal;font-weight:800;font-size:.83rem}.question-card>p{margin:.7rem 0}.question-card ol{margin:.45rem 0;padding-left:1.5rem}.answer-toggle{margin-top:10px;border:1px solid #c6ecd2;border-radius:11px;overflow:hidden;background:#fff}.answer-toggle summary{cursor:pointer;list-style:none;background:var(--math-green);color:#fff;font-weight:900;padding:10px 13px;user-select:none}.answer-toggle summary::-webkit-details-marker{display:none}.answer-toggle summary:after{content:"＋";float:right;font-size:1.1rem}.answer-toggle[open] summary:after{content:"−"}.answer-toggle summary:hover{background:var(--math-green-dark)}.answer-body{padding:12px 14px;background:var(--math-green-soft)}.answer-body p{margin:.45rem 0}.answer-body mjx-container[display="true"]{margin:.65em 0!important}
.math-revision-box{background:linear-gradient(135deg,var(--math-purple-dark),var(--math-purple));color:#fff;border:none}.math-revision-box h2{color:#fff;margin:.05rem 0 .8rem}.revision-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:11px}.revision-grid>div{background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.2);border-radius:12px;padding:12px}.revision-grid strong{color:#dff8e8}.revision-grid p{margin:.35rem 0 0;color:#f7f4ff}.math-next-pending{display:inline-flex;align-items:center;justify-content:center;padding:9px 14px;border-radius:999px;background:#f3f4f6;color:#6b7280;font-size:.9rem;font-weight:800}.math-chapter-link{display:inline-flex;margin-top:10px;color:#fff;background:var(--math-purple);text-decoration:none;font-weight:900;padding:7px 11px;border-radius:10px}.math-chapter-link:hover{background:var(--math-purple-dark)}
@media(max-width:800px){.math-notes-page{padding:12px 9px 32px}.math-chapter-hero{padding:22px 17px;border-radius:20px}.math-learning-box{grid-template-columns:1fr}.math-concept-grid{grid-template-columns:1fr 1fr}.math-method-columns,.math-rule-row,.math-definition-pair{grid-template-columns:1fr}.math-topic,.math-practice{padding:16px 13px;border-radius:17px}.math-table{display:block;overflow-x:auto;-webkit-overflow-scrolling:touch}.math-mini-grid{grid-template-columns:1fr}.revision-grid{grid-template-columns:1fr}.q-head em{margin-left:0;width:100%;padding-left:39px}}
@media(max-width:760px){.math-page-toc ol{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:520px){.math-concept-grid{grid-template-columns:1fr}.math-chapter-hero h2{font-size:2.35rem}.math-topic-heading h2{font-size:1.35rem}.math-page-toc ol{grid-template-columns:1fr}.chapter-top-nav .math-next-pending{width:100%;box-sizing:border-box}.q-head em{padding-left:0}}


/* Chapter 2 Venn diagram learning visuals */
.math-venn-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.math-venn-card{background:#f8fafc;border:1px solid #dde2e9;border-radius:15px;padding:14px;text-align:center}.math-venn-card>strong{display:block;color:var(--math-purple-dark);margin-top:8px}.math-venn-card p{margin:.3rem 0}.venn-two,.venn-subset{position:relative;height:118px;max-width:210px;margin:0 auto;border:2px solid #94a3b8;border-radius:8px;background:#fff}.venn-two .circle{position:absolute;top:24px;width:82px;height:64px;border:3px solid var(--math-purple);border-radius:50%;display:flex;align-items:flex-start;justify-content:center;padding-top:5px;box-sizing:border-box;font-weight:900;color:var(--math-purple-dark);background:rgba(109,40,217,.05)}.venn-two.overlap .a{left:30px}.venn-two.overlap .b{right:30px;border-color:var(--math-green);color:var(--math-green-dark);background:rgba(21,148,71,.05)}.venn-two.disjoint .a{left:16px}.venn-two.disjoint .b{right:16px;border-color:var(--math-green);color:var(--math-green-dark);background:rgba(21,148,71,.05)}.venn-subset:before{content:"";position:absolute;left:39px;top:18px;width:125px;height:78px;border:3px solid var(--math-purple);border-radius:50%;background:rgba(109,40,217,.04)}.venn-subset:after{content:"";position:absolute;left:78px;top:39px;width:62px;height:42px;border:3px solid var(--math-green);border-radius:50%;background:rgba(21,148,71,.06)}.venn-subset .outer{position:absolute;left:50px;top:23px;z-index:2;font-weight:900;color:var(--math-purple-dark)}.venn-subset .inner{position:absolute;left:102px;top:47px;z-index:2;font-weight:900;color:var(--math-green-dark)}
@media(max-width:760px){.math-venn-grid{grid-template-columns:1fr}.math-venn-card{max-width:420px;width:100%;box-sizing:border-box;margin:0 auto}}


/* Enhanced Chapter 2 Venn teaching and practice visuals */
.venn-worked-layout{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(270px,.95fr);gap:18px;align-items:center}.venn-figure{background:#fff;border:1px solid #d9dee7;border-radius:15px;padding:10px;box-shadow:0 3px 10px rgba(15,23,42,.04)}.venn-svg{display:block;width:100%;max-width:390px;height:auto;margin:0 auto}.venn-caption{font-size:.86rem;color:#64748b;text-align:center;margin:.4rem .25rem .1rem}.venn-label{font:900 17px Arial,sans-serif}.venn-label.purple{fill:#4c1d95}.venn-label.green{fill:#116a35}.venn-label.amber{fill:#9a5600}.venn-values{font:800 14px Arial,sans-serif;fill:#263247}.venn-values.small{font-size:12px}.venn-number{font:900 17px Arial,sans-serif;fill:#263247}.venn-shading-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:17px 0}.venn-shade-card{background:#f8fafc;border:1px solid #dce2e9;border-radius:15px;padding:12px;text-align:center}.venn-shade-card strong{display:block;color:var(--math-purple-dark);font-size:1.05rem;margin-top:4px}.venn-shade-card p{margin:.25rem 0 0;color:#536174;font-size:.92rem}.venn-question-visual{max-width:380px;background:#f8fafc;border:1px solid #dce2e9;border-radius:14px;padding:10px;margin:12px auto}.subset-visual-row{margin:17px 0;background:#fafbff;border:1px solid #e4e0f5;border-radius:15px;padding:14px}.math-table.compact th,.math-table.compact td{padding:8px 9px}.question-card .venn-svg{max-width:340px}
@media(max-width:820px){.venn-worked-layout{grid-template-columns:1fr}.venn-shading-grid{grid-template-columns:1fr 1fr}.venn-figure{max-width:520px;width:100%;box-sizing:border-box;margin:0 auto}}
@media(max-width:540px){.venn-shading-grid{grid-template-columns:1fr}.venn-question-visual{padding:7px}.venn-figure{padding:7px}.venn-label{font-size:15px}.venn-number{font-size:15px}}

/* Chapter 4 fraction equivalence visual */
.fraction-visual-row{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.fraction-visual-card{background:#f8fafc;border:1px solid #dde2e9;border-radius:15px;padding:14px;text-align:center}.fraction-visual-card>strong{display:block;color:var(--math-purple-dark);font-size:1.1rem;margin-bottom:10px}.fraction-strip{display:grid;height:34px;border:2px solid #94a3b8;border-radius:8px;overflow:hidden;background:#fff}.fraction-strip.two{grid-template-columns:repeat(2,1fr)}.fraction-strip.four{grid-template-columns:repeat(4,1fr)}.fraction-strip.eight{grid-template-columns:repeat(8,1fr)}.fraction-strip span{border-right:1px solid #cbd5e1}.fraction-strip span:last-child{border-right:none}.fraction-strip .on{background:linear-gradient(135deg,var(--math-purple),var(--math-green))}@media(max-width:620px){.fraction-visual-row{grid-template-columns:1fr}}


/* Chapter 5 ordering visual */
.order-number-line{position:relative;display:grid;grid-template-columns:repeat(11,minmax(38px,1fr));gap:0;margin:24px 0 18px;padding-top:18px;overflow-x:auto;-webkit-overflow-scrolling:touch}.order-number-line:before{content:"";position:absolute;left:18px;right:18px;top:25px;height:3px;background:linear-gradient(90deg,var(--math-purple),var(--math-green));border-radius:999px}.order-number-line span{position:relative;z-index:1;min-width:38px;text-align:center;padding-top:18px;color:var(--math-purple-dark);font-weight:900}.order-number-line span:before{content:"";position:absolute;top:1px;left:50%;transform:translateX(-50%);width:12px;height:12px;border-radius:50%;background:#fff;border:3px solid var(--math-green)}

/* Chapter 6 arithmetic visuals */
.operation-ladder{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:16px 0}.operation-ladder>div{display:flex;align-items:center;gap:10px;background:#f8fafc;border:1px solid #dce2ea;border-radius:14px;padding:12px}.operation-ladder strong{width:31px;height:31px;display:grid;place-items:center;border-radius:9px;background:var(--math-purple);color:#fff}.operation-ladder span{font-weight:850;color:var(--math-purple-dark)}.sign-table td:last-child{font-weight:900;color:var(--math-green-dark)}
@media(max-width:700px){.operation-ladder{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:430px){.operation-ladder{grid-template-columns:1fr}}

/* Chapter 8 standard-form visual */
.standard-form-visual{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:16px 0}.standard-form-visual>div{display:grid;gap:7px;text-align:center;background:#f8fafc;border:1px solid #dde2e9;border-radius:15px;padding:14px}.standard-form-visual strong{color:var(--math-purple-dark)}.standard-form-visual .arrow{color:var(--math-green);font-size:1.35rem;font-weight:950}.standard-form-visual small{color:#64748b;line-height:1.4}@media(max-width:620px){.standard-form-visual{grid-template-columns:1fr}}

/* Chapter 9 estimation visuals */
.estimate-benchmarks{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:16px 0}.estimate-benchmarks>div{background:linear-gradient(180deg,#fff,#f8fafc);border:1px solid #dce2ea;border-top:4px solid var(--math-green);border-radius:14px;padding:13px;text-align:center}.estimate-benchmarks strong{display:block;color:var(--math-purple-dark);font-size:1.08rem}.estimate-benchmarks span{display:block;color:#64748b;font-size:.9rem;margin-top:3px}@media(max-width:760px){.estimate-benchmarks{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:420px){.estimate-benchmarks{grid-template-columns:1fr}}


/* Chapter 10 bounds figures */
.bounds-figure{margin:20px 0;background:#f8fafc;border:1px solid #d8dee8;border-radius:18px;padding:14px 16px;overflow:hidden}.bounds-figure figcaption{font-weight:900;color:var(--math-purple-dark);margin-bottom:8px}.bounds-figure svg{display:block;width:100%;height:auto;max-width:850px;margin:0 auto}.bounds-figure svg text{font-family:Arial,sans-serif;fill:#334155;font-size:18px}.bounds-figure .axis{stroke:#475569;stroke-width:4;stroke-linecap:round}.bounds-figure .tick{stroke:#64748b;stroke-width:3}.bounds-figure .tick.main{stroke:var(--math-purple);stroke-width:5}.bounds-figure .bound{stroke-width:4;stroke-dasharray:8 6}.bounds-figure .bound.lower{stroke:var(--math-green)}.bounds-figure .bound.upper{stroke:var(--math-purple)}.bounds-figure .active-range{stroke:#86efac;stroke-width:14;stroke-linecap:round}.bounds-figure .closed-dot{fill:var(--math-green);stroke:#fff;stroke-width:3}.bounds-figure .open-dot{fill:#fff;stroke:var(--math-purple);stroke-width:4}.bounds-figure .figure-note{fill:var(--math-green-dark);font-weight:800}.figure-explain{margin:9px 0 0;text-align:center;color:#475569}.bounds-rule-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px;margin:16px 0}.bounds-rule-grid article{background:linear-gradient(180deg,#fff,#f7f5ff);border:1px solid #ddd6fe;border-top:5px solid var(--math-purple);border-radius:15px;padding:14px}.bounds-rule-grid article:nth-child(2){border-top-color:var(--math-green)}.bounds-rule-grid h3{margin:.05rem 0 .5rem;color:var(--math-purple-dark)}.range-box.purple{fill:#ede9fe;stroke:#7c3aed;stroke-width:3}.range-box.green{fill:#dcfce7;stroke:#159447;stroke-width:3}.svg-label{font-weight:900;fill:var(--math-purple-dark)!important}.outer-bound{fill:#ede9fe;stroke:#6d28d9;stroke-width:4}.inner-bound{fill:#dcfce7;stroke:#159447;stroke-width:4;stroke-dasharray:8 5}.dimension-line{stroke:#64748b;stroke-width:2}.speed-bound-cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.speed-bound-cards>div{display:grid;gap:5px;text-align:center;background:#fff;border:1px solid #d7dce4;border-radius:15px;padding:16px}.speed-bound-cards strong{color:var(--math-purple-dark)}.speed-bound-cards span{font-weight:800}.speed-bound-cards .divide-line{height:2px;background:#64748b;margin:2px 18%}.speed-bound-cards em{font-style:normal;color:var(--math-green-dark);font-weight:900;margin-top:5px}.compact-figure svg{max-width:720px}
@media(max-width:700px){.bounds-rule-grid,.speed-bound-cards{grid-template-columns:1fr}.bounds-figure{padding:12px 8px}.bounds-figure svg text{font-size:15px}}


/* Chapter 11 ratio and proportion visuals */
.ratio-visual,.ratio-share-figure,.scale-figure,.proportion-compare{margin:18px 0}
.ratio-visual>div{background:#f8fafc;border:1px solid #d9dee8;border-radius:16px;padding:16px;text-align:center}
.ratio-bar{display:grid;grid-template-columns:repeat(10,1fr);gap:4px;max-width:620px;margin:12px auto}.ratio-bar span{height:34px;border-radius:5px}.ratio-bar .p,.shares .p{background:var(--math-purple)}.ratio-bar .g,.shares .g{background:var(--math-green)}
.scale-figure{display:flex;align-items:center;justify-content:center;gap:18px;flex-wrap:wrap}.map-card{min-width:210px;background:#f8fafc;border:1px solid #d9dee8;border-radius:15px;padding:14px;text-align:center}.map-card.real{border-top:5px solid var(--math-green)}.map-card:not(.real){border-top:5px solid var(--math-purple)}.map-line{display:block;height:5px;border-radius:9px;background:#334155;margin:14px 18px 9px}.scale-arrow{font-size:1.6rem;font-weight:900;color:var(--math-purple-dark)}
.ratio-share-figure{background:#f8fafc;border:1px solid #d9dee8;border-radius:16px;padding:16px}.share-title{text-align:center;font-weight:900;color:var(--math-purple-dark);margin-bottom:12px}.shares{display:grid;grid-template-columns:repeat(8,1fr);gap:5px}.shares span{min-height:54px;color:#fff;font-weight:900;display:grid;place-items:center;border-radius:7px}.share-labels{display:grid;grid-template-columns:3fr 5fr;gap:8px;margin-top:8px;text-align:center;color:#334155}
.proportion-compare{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.proportion-compare article{background:#f8fafc;border:1px solid #d9dee8;border-radius:16px;padding:16px}.proportion-compare article:first-child{border-top:5px solid var(--math-green)}.proportion-compare article:last-child{border-top:5px solid var(--math-purple)}.prop-arrows{display:flex;justify-content:space-between;gap:10px;background:#eefbf2;border-radius:10px;padding:10px;margin:10px 0;font-weight:900}.prop-arrows.inverse{background:#f1edff}.ratio-table-wrap{max-width:520px;margin:16px auto}
@media(max-width:620px){.proportion-compare{grid-template-columns:1fr}.shares{grid-template-columns:repeat(4,1fr)}.share-labels{grid-template-columns:1fr}.ratio-bar{grid-template-columns:repeat(5,1fr)}}


/* Chapter 12 figures */
.rate-figure-grid,.compound-figure-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}
.compound-figure-grid{grid-template-columns:repeat(3,minmax(0,1fr))}
.rate-figure-card,.compound-card,.dst-card,.unit-convert-card{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}
.rate-figure-card h3,.compound-card h3,.dst-card h3,.unit-convert-card h3{margin-top:0;color:var(--math-purple-dark)}
.formula-pill{display:inline-block;background:var(--math-green-soft);border:1px solid #cde9d7;border-radius:999px;padding:7px 12px;font-weight:800;color:var(--math-green-dark);margin:4px 0 12px}
.pay-figure{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;background:#fff;border:1px dashed #cdd6e3;border-radius:14px;padding:16px 12px;margin:8px 0 10px}
.pay-figure span{font-size:1.1rem;font-weight:900;color:var(--math-purple-dark)}
.pay-figure small{display:block;width:100%;text-align:center;color:#475569;font-weight:700;margin-top:-4px}
.pay-figure .times,.pay-figure .equals{font-size:1.25rem;font-weight:900;color:var(--math-green-dark)}
.pay-figure b{font-size:1.18rem;color:var(--math-green-dark)}
.tank-figure{display:flex;align-items:center;justify-content:space-between;gap:12px;background:#fff;border:1px dashed #cdd6e3;border-radius:14px;padding:14px;margin:8px 0 10px}
.tank{width:82px;height:110px;border:4px solid #6b7280;border-radius:0 0 12px 12px;position:relative;overflow:hidden;background:#f8fafc}
.water-level{position:absolute;left:0;right:0;bottom:0;height:72%;background:linear-gradient(180deg,#86efac,#34d399)}
.pipe{background:var(--math-purple-soft);color:var(--math-purple-dark);padding:10px 12px;border-radius:12px;font-weight:900;border:1px solid #ddd6fe}
.speed-figure-wrap{display:grid;grid-template-columns:1.05fr .95fr;gap:14px;margin:16px 0}
.dst-triangle{width:220px;max-width:100%;aspect-ratio:1.15/1;margin:10px auto 12px;position:relative;background:linear-gradient(160deg,#ede9fe,#dcfce7);clip-path:polygon(50% 0,100% 100%,0 100%);border:2px solid #b7c2d3}
.dst-triangle .top,.triangle-stack .triangle-label.top{position:absolute;left:50%;transform:translateX(-50%);top:22%;font-size:1.7rem;font-weight:900;color:var(--math-purple-dark)}
.dst-triangle .bottom{position:absolute;bottom:14%;font-size:1.35rem;font-weight:900;color:var(--math-green-dark)}
.dst-triangle .bottom.left{left:28%}.dst-triangle .bottom.right{right:28%}
.convert-grid{display:grid;grid-template-columns:1fr;gap:10px}
.convert-grid div{display:flex;justify-content:space-between;gap:10px;padding:10px 12px;background:#fff;border:1px solid #e2e8f0;border-radius:12px}
.convert-grid strong{color:var(--math-purple-dark)}
.triangle-stack{position:relative;width:185px;max-width:100%;aspect-ratio:1.1/1;margin:8px auto 14px;background:linear-gradient(160deg,#ede9fe,#dcfce7);clip-path:polygon(50% 0,100% 100%,0 100%);border:2px solid #b7c2d3}
.triangle-stack .triangle-row{position:absolute;bottom:14%;left:0;right:0;display:flex;justify-content:space-around;font-weight:900;color:var(--math-green-dark)}
@media(max-width:900px){.compound-figure-grid{grid-template-columns:1fr}.rate-figure-grid,.speed-figure-wrap{grid-template-columns:1fr}}
@media(max-width:560px){.pay-figure{padding:12px 8px}.tank{width:72px;height:100px}.formula-pill{font-size:.94rem}}


/* Chapter 13 percentage visuals */
.percent-conversion-figure{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:16px 0}.percent-conversion-figure>div{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:10px;background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:14px;text-align:center}.percent-conversion-figure strong{color:var(--math-purple-dark)}.percent-conversion-figure span{background:var(--math-green-soft);color:var(--math-green-dark);font-weight:900;border-radius:999px;padding:7px 10px}
.percent-bar{display:flex;overflow:hidden;border-radius:14px;border:1px solid #dbe3ee;height:54px;margin:16px 0;font-weight:900}.percent-bar>div{display:flex;align-items:center;justify-content:center;background:#ddd6fe;color:var(--math-purple-dark)}.percent-bar>div:nth-child(2){background:#bbf7d0;color:var(--math-green-dark)}.percent-bar .rest{flex:1;background:#f8fafc;color:#64748b}
.percentage-change-figure{display:flex;align-items:center;justify-content:center;gap:14px;flex-wrap:wrap;background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;margin:16px 0}.percentage-change-figure .old,.percentage-change-figure .new{padding:13px 18px;border-radius:14px;font-weight:800;text-align:center}.percentage-change-figure .old{background:#ede9fe;color:var(--math-purple-dark)}.percentage-change-figure .new{background:#dcfce7;color:var(--math-green-dark)}.percentage-change-figure .arrow{font-weight:900;color:#475569}.percentage-change-figure small{flex-basis:100%;text-align:center;color:#64748b}
.multiplier-figure{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.multiplier-figure>div{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;display:grid;gap:7px}.multiplier-figure b{color:var(--math-purple-dark)}.multiplier-figure strong{font-size:1.4rem;color:var(--math-green-dark)}
.reverse-percent-figure{display:flex;align-items:center;justify-content:center;gap:18px;flex-wrap:wrap;margin:18px 0}.reverse-percent-figure .node{background:#f8fafc;border:2px solid #c4b5fd;border-radius:15px;padding:18px 24px;font-weight:900;color:var(--math-purple-dark)}.reverse-percent-figure .route{display:grid;grid-template-columns:auto auto auto;gap:8px;align-items:center;color:#475569;font-weight:900}.reverse-percent-figure .route span{background:var(--math-green-soft);padding:8px 10px;border-radius:999px;color:var(--math-green-dark)}
.repeated-change-figure{display:flex;align-items:center;gap:8px;flex-wrap:wrap;justify-content:center;background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:15px;margin:16px 0}.repeated-change-figure span{background:#fff;border:1px solid #ddd6fe;border-radius:12px;padding:10px 12px;font-weight:900;color:var(--math-purple-dark)}.repeated-change-figure b{color:var(--math-green-dark)}
.interest-compare{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.interest-compare article{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px}.interest-compare h3{margin-top:0;color:var(--math-purple-dark)}.mini-growth{display:flex;align-items:flex-end;gap:6px;height:100px;margin-top:12px}.mini-growth span{flex:1;background:#ddd6fe;border-radius:7px 7px 0 0;padding:6px 2px;text-align:center;font-size:.75rem;font-weight:800;color:var(--math-purple-dark)}.mini-growth span:nth-child(1){height:48%}.mini-growth span:nth-child(2){height:62%}.mini-growth span:nth-child(3){height:76%}.mini-growth span:nth-child(4){height:90%}.mini-growth.compound span:nth-child(3){height:80%}.mini-growth.compound span:nth-child(4){height:98%;background:#bbf7d0;color:var(--math-green-dark)}
@media(max-width:720px){.percent-conversion-figure,.multiplier-figure,.interest-compare{grid-template-columns:1fr}.reverse-percent-figure .route{grid-template-columns:1fr;text-align:center}.repeated-change-figure{flex-direction:column}.math-page-toc ol{grid-template-columns:repeat(2,minmax(0,1fr))}}


/* Chapter 14 calculator visuals */
.calc-rule-flow{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:8px;margin:16px 0}.calc-rule-flow div{background:#fff;border:1px solid #ddd6fe;border-top:4px solid var(--math-purple);border-radius:13px;padding:10px 13px;font-weight:850;color:var(--math-purple-dark)}.calc-rule-flow span{font-weight:900;color:var(--math-green-dark)}
.calc-display-card{background:#e8ecdf;border:2px solid #67705f;border-radius:16px;padding:14px;margin:16px 0;box-shadow:inset 0 0 0 4px #f4f6ef}.calc-screen,.mini-screen{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;background:#cbd5b9;border:1px solid #64745a;border-radius:7px;padding:12px;color:#172113;letter-spacing:.02em;overflow-x:auto}.calc-screen{font-size:1.05rem}.calc-keys{display:flex;flex-wrap:wrap;gap:7px;margin-top:12px}.calc-keys span,.fake-key{background:#fff;border:1px solid #aeb7a4;border-bottom:3px solid #8b9582;border-radius:7px;padding:7px 9px;font-weight:800;font-size:.88rem}.calc-output{text-align:right;font-weight:900;margin-top:10px;color:#1f2937}
.check-method-grid,.display-interpret-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.check-method-grid article,.display-interpret-grid article{background:#f8fafc;border:1px solid #dbe3ee;border-radius:15px;padding:14px}.check-method-grid h3,.display-interpret-grid h3{color:var(--math-purple-dark);margin:.4rem 0}.mini-screen{margin-bottom:10px}
.time-convert-figure{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.time-convert-figure>div{background:linear-gradient(135deg,var(--math-purple-soft),var(--math-green-soft));border:1px solid #d8d6ea;border-radius:16px;padding:15px}.time-convert-figure strong{display:block;color:var(--math-purple-dark);margin-bottom:8px}.time-convert-figure span{display:inline-block;background:#fff;border:1px solid #dce2ea;border-radius:999px;padding:5px 9px;font-size:.87rem;font-weight:800;color:var(--math-green-dark)}
.fraction-key-figure{display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:14px;background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;margin:16px 0}.fake-key{font-size:1rem;color:var(--math-purple-dark);text-align:center}.key-sequence{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-weight:750;line-height:1.9}.key-sequence span{background:#fff;border:1px solid #d6dde8;border-radius:6px;padding:3px 6px;margin:0 2px;font-size:.86rem}
@media(max-width:760px){.check-method-grid,.display-interpret-grid{grid-template-columns:1fr}.time-convert-figure{grid-template-columns:1fr}.fraction-key-figure{grid-template-columns:1fr}.calc-rule-flow{justify-content:flex-start}}


/* Chapter 15 figures */
.time-figure-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}
.time-figure-grid.two-col{grid-template-columns:repeat(2,minmax(0,1fr))}
.figure-card{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}
.figure-card h3{margin-top:0;color:var(--math-purple-dark)}
.figure-note{font-size:.95rem;color:#475569;margin:.6rem 0 0}
.day-wrap{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:10px}
.day-block{background:#fff;border:1px solid #e2e8f0;border-radius:14px;padding:12px}
.day-block strong{display:block;color:var(--math-green-dark);margin-bottom:8px}
.time-map{display:flex;justify-content:space-between;gap:10px;padding:8px 10px;border-radius:10px;background:#f8fafc;border:1px solid #edf2f7;margin-bottom:8px}
.time-map b{color:var(--math-purple-dark)}
.dayline{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;align-items:stretch;margin:12px 0}
.dayline div{background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:10px;text-align:center}
.dayline span{display:block;font-weight:900;color:var(--math-purple-dark)}
.dayline small{color:#64748b}
.clock-key-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.clock-key-grid div{background:linear-gradient(180deg,#ede9fe,#dcfce7);border:1px solid #d7d9e2;border-radius:12px;padding:10px;text-align:center}
.clock-key-grid b{display:block;color:var(--math-purple-dark)}
.timeline-figure{margin-top:10px}
.timeline{display:flex;align-items:center;gap:0;margin:12px 0 8px}
.timeline .dot{width:14px;height:14px;background:var(--math-purple);border:3px solid #ede9fe;border-radius:50%;box-shadow:0 0 0 1px var(--math-purple)}
.timeline .segment{height:6px;background:linear-gradient(90deg,var(--math-green),var(--math-purple));border-radius:999px;display:block}
.timeline .short{width:70px}.timeline .medium{width:110px}.timeline .long{width:150px}
.timeline-labels{display:flex;justify-content:space-between;gap:8px;font-size:.95rem;color:#334155}
.timetable-card table th,.timetable-card table td{text-align:center}
.conversion-box{background:#fff;border:1px dashed #cdd6e3;border-radius:14px;padding:14px}
.conversion-box div{display:grid;gap:8px}
.conversion-box b{font-size:1.12rem;color:var(--math-purple-dark)}
.conversion-box strong{font-size:1.08rem;color:var(--math-green-dark)}
.timezone-strip{display:grid;grid-template-columns:1fr auto 1fr;gap:10px;align-items:center;margin:10px 0;background:#fff;border:1px solid #e2e8f0;border-radius:14px;padding:12px}
.timezone-strip div{text-align:center}
.timezone-strip b{display:block;color:var(--math-purple-dark)}
.timezone-strip .offset{background:var(--math-green-soft);border:1px solid #cde9d7;border-radius:999px;padding:8px 10px;font-weight:900;color:var(--math-green-dark)}
.method-steps{padding-left:1.1rem;margin:.3rem 0}.method-steps li{margin:.45rem 0}
@media(max-width:900px){.time-figure-grid,.time-figure-grid.two-col{grid-template-columns:1fr}.day-wrap,.clock-key-grid{grid-template-columns:1fr}}
@media(max-width:560px){.dayline{grid-template-columns:1fr 1fr}.timezone-strip{grid-template-columns:1fr}.timezone-strip .offset{justify-self:center}.timeline .short{width:42px}.timeline .medium{width:70px}.timeline .long{width:96px}.timeline-labels{font-size:.85rem}}


/* Chapter 16 figures */
.money-figure-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.money-figure-card,.currency-figure,.cross-rate-figure{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}.money-figure-card h3,.currency-figure h3,.cross-rate-figure h3{margin-top:0;color:var(--math-purple-dark)}
.unit-price-figure{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:10px}.unit-price-figure>div:not(.compare-sign){display:grid;gap:5px;text-align:center;background:#fff;border:1px solid #e2e8f0;border-radius:13px;padding:12px}.unit-price-figure b{color:var(--math-purple-dark);font-size:1.08rem}.unit-price-figure span{color:#64748b}.unit-price-figure strong{color:var(--math-green-dark)}.compare-sign{font-weight:950;color:var(--math-purple);font-size:1.1rem}.value-decision{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin:14px 0}.value-decision>div{background:linear-gradient(180deg,#ede9fe,#ecfdf5);border:1px solid #d8d8ea;border-radius:14px;padding:13px}.value-decision span,.value-decision b{display:block}.value-decision b{color:var(--math-green-dark);margin:.35rem 0}.value-decision p{margin:0;color:#475569}
.currency-figure{margin:16px 0}.currency-flow{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:12px;margin:12px 0}.currency-box{background:#fff;border:1px solid #e2e8f0;border-radius:14px;padding:14px;text-align:center}.currency-box b{display:block;color:var(--math-purple-dark)}.currency-box span{font-size:1.18rem;font-weight:900;color:var(--math-green-dark)}.currency-arrow{text-align:center;background:var(--math-green-soft);border:1px solid #cde9d7;border-radius:999px;padding:8px 13px;color:var(--math-green-dark)}.currency-arrow strong,.currency-arrow small{display:block}.reverse-flow .currency-arrow{background:var(--math-purple-soft);border-color:#ddd6fe;color:var(--math-purple-dark)}.cross-rate-figure{margin:16px 0}.hub{display:flex;justify-content:center;align-items:center;gap:12px;flex-wrap:wrap;margin:12px 0}.hub-box{min-width:86px;text-align:center;background:#fff;border:2px solid var(--math-purple);border-radius:14px;padding:13px;font-weight:950;color:var(--math-purple-dark)}.hub-arrow{background:var(--math-green-soft);border:1px solid #cde9d7;border-radius:999px;padding:9px 14px;font-weight:900;color:var(--math-green-dark)}
@media(max-width:760px){.money-figure-grid{grid-template-columns:1fr}.currency-flow,.unit-price-figure{grid-template-columns:1fr}.currency-arrow,.compare-sign{justify-self:center}.value-decision{grid-template-columns:1fr}}


/* Chapter 17 exponential figures */
.exp-figure-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}
.exp-figure-card{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}
.exp-figure-card h3{margin-top:0;color:var(--math-purple-dark)}
.multiplier-chain{display:flex;align-items:center;justify-content:center;gap:7px;flex-wrap:wrap;margin:14px 0}
.multiplier-chain>div{background:#fff;border:1px solid #ddd6fe;border-radius:12px;padding:10px 12px;text-align:center;min-width:84px}
.multiplier-chain>div b{display:block;color:var(--math-purple-dark);font-size:1.05rem}.multiplier-chain>div small{color:#64748b}.multiplier-chain>span{font-weight:900;color:var(--math-green-dark)}
.multiplier-chain.decay>div{border-color:#cde9d7}.multiplier-chain.decay>span{color:#9f1239}
.percent-to-mult{display:flex;align-items:center;justify-content:center;gap:12px;background:#fff;border:1px dashed #cdd6e3;border-radius:14px;padding:15px;text-align:center;font-weight:800}.percent-to-mult strong{font-size:1.4rem;color:var(--math-green-dark)}
.mini-examples{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin:12px 0}.mini-examples span{background:var(--math-purple-soft);border:1px solid #ddd6fe;color:var(--math-purple-dark);padding:7px 10px;border-radius:999px;font-weight:800}
.growth-decay-compare{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:16px 0}.growth-decay-compare>div{border-radius:15px;padding:15px;background:#fff;border:1px solid #e2e8f0}.growth-decay-compare strong{display:block;color:var(--math-purple-dark);font-size:1.05rem}.growth-decay-compare span{display:inline-block;margin:.4rem 0;padding:5px 9px;border-radius:999px;background:var(--math-green-soft);color:var(--math-green-dark);font-weight:800}
@media(max-width:800px){.exp-figure-grid,.growth-decay-compare{grid-template-columns:1fr}}
@media(max-width:520px){.multiplier-chain{align-items:stretch}.multiplier-chain>span{align-self:center}.percent-to-mult{flex-direction:column;gap:6px}}


/* Chapter 18 surd figures */
.surd-figure-grid,.rationalise-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}
.surd-figure-card,.rationalise-card{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}
.surd-figure-card h3,.rationalise-card h3{margin-top:0;color:var(--math-purple-dark)}
.factor-flow,.rationalise-flow{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;background:#fff;border:1px dashed #cbd5e1;border-radius:14px;padding:14px}
.factor-flow div{text-align:center;background:var(--math-purple-soft);border:1px solid #ddd6fe;border-radius:12px;padding:10px 12px}
.factor-flow div small{display:block;color:#64748b;margin-top:5px}.factor-flow>span,.rationalise-flow>span:nth-child(2),.rationalise-flow>span:nth-child(4){font-weight:950;color:var(--math-green-dark);font-size:1.15rem}
.square-chip-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}.square-chip-grid span{background:#fff;border:1px solid #e2e8f0;border-radius:10px;padding:8px;text-align:center;font-weight:800;color:var(--math-purple-dark)}
.like-surd-demo{display:flex;align-items:center;justify-content:center;gap:8px;flex-wrap:wrap;background:#fff;border:1px dashed #cbd5e1;border-radius:14px;padding:16px;margin-bottom:8px}.like-surd-demo strong{color:var(--math-green-dark)}
.rationalise-flow strong{color:var(--math-green-dark);background:var(--math-green-soft);border:1px solid #cde9d7;border-radius:10px;padding:8px 10px}
.conjugate-pair{display:grid;grid-template-columns:1fr auto 1fr;gap:8px;align-items:center;background:#fff;border:1px dashed #cbd5e1;border-radius:14px;padding:14px;text-align:center}.conjugate-pair span{background:var(--math-purple-soft);border:1px solid #ddd6fe;border-radius:10px;padding:10px;font-weight:900;color:var(--math-purple-dark)}.conjugate-pair b{font-size:.82rem;text-transform:uppercase;color:var(--math-green-dark)}
@media(max-width:800px){.surd-figure-grid,.rationalise-grid{grid-template-columns:1fr}.square-chip-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:480px){.conjugate-pair{grid-template-columns:1fr}.factor-flow{flex-direction:column}.square-chip-grid{grid-template-columns:1fr 1fr}}


/* Chapter 19 algebra visuals */
.algebra-visual-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.algebra-visual-card,.hard-number-grid article{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}.algebra-visual-card h3,.hard-number-grid h3{margin-top:0;color:var(--math-purple-dark)}.formula-flow{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap}.formula-flow>div:not(.flow-op){background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:10px 12px;text-align:center;min-width:120px}.formula-flow strong{display:block;color:#334155;font-size:.9rem}.formula-flow span{display:block;color:var(--math-purple-dark);font-size:1.25rem;font-weight:900;margin-top:4px}.flow-op,.sub-flow .arrow{font-weight:950;color:var(--math-green-dark);font-size:1.2rem}.formula-banner{margin:12px auto 0;text-align:center;background:linear-gradient(135deg,var(--math-purple-soft),var(--math-green-soft));border:1px solid #d8d9e9;border-radius:12px;padding:10px;font-size:1.2rem;font-weight:900;color:var(--math-purple-dark)}.notation-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}.notation-grid div{display:flex;align-items:center;justify-content:space-between;gap:10px;background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:10px}.notation-grid span{color:#64748b}.notation-grid b{color:var(--math-green-dark)}.sub-flow{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap}.sub-flow>div:not(.arrow){background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:10px 12px;text-align:center}.sub-flow b{display:block;color:#475569;font-size:.85rem;margin-bottom:4px}.sub-flow span{font-size:1.05rem;color:var(--math-purple-dark);font-weight:900}.negative-box{background:#fff;border:1px dashed #cbd5e1;border-radius:14px;padding:14px;text-align:center}.negative-box div{font-size:1.2rem;font-weight:900;color:var(--math-purple-dark)}.hard-number-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.hard-number-grid article{text-align:center}.hard-number-grid article>div{display:inline-block;margin-top:6px;padding:8px 12px;border-radius:999px;background:var(--math-green-soft);color:var(--math-green-dark);font-weight:900}@media(max-width:850px){.algebra-visual-grid,.hard-number-grid{grid-template-columns:1fr}}@media(max-width:560px){.notation-grid{grid-template-columns:1fr}.formula-flow,.sub-flow{flex-direction:column}.flow-op,.sub-flow .arrow{transform:rotate(90deg)}}


/* Chapter 20 algebraic manipulation visuals */
.alg20-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.alg20-card,.distribution-figure,.inverse-figure,.grouping-figure,.pattern-figure,.product-sum,.perfect-square-figure,.cross-figure,.complete-square-figure{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}.alg20-card h3{margin-top:0;color:var(--math-purple-dark)}.term-sort,.identity-row{display:flex;gap:9px;flex-wrap:wrap;justify-content:center;margin:10px 0}.term-sort span,.identity-row span{background:#fff;border:1px solid #ddd6fe;border-radius:10px;padding:8px 11px;font-weight:850;color:var(--math-purple-dark)}.identity-row .no{border-color:#fecaca;color:#991b1b}.alg20-card>strong{display:block;text-align:center;color:var(--math-green-dark)}
.distribution-figure{text-align:center;margin:16px 0}.distribution-figure .outside{display:inline-block;background:var(--math-purple-soft);padding:10px 15px;border-radius:12px;font-weight:900}.distribution-figure .arrows{font-size:1.4rem;color:var(--math-green-dark);margin:5px}.distribution-figure .inside{display:flex;justify-content:center;gap:12px}.distribution-figure .inside span{background:#fff;border:1px solid #e2e8f0;border-radius:10px;padding:8px 12px}.distribution-figure .result{margin-top:10px;font-weight:900;color:var(--math-purple-dark)}
.inverse-figure,.grouping-figure,.pattern-figure,.complete-square-figure,.perfect-square-figure{display:flex;align-items:center;justify-content:center;gap:12px;flex-wrap:wrap;margin:16px 0;text-align:center}.inverse-figure div,.grouping-figure div,.pattern-figure div,.complete-square-figure div,.perfect-square-figure span{background:#fff;border:1px solid #e2e8f0;border-radius:11px;padding:9px 12px}.inverse-figure span,.grouping-figure span,.pattern-figure span,.complete-square-figure span{font-weight:900;color:var(--math-green-dark)}.grouping-figure strong,.pattern-figure strong,.complete-square-figure strong,.perfect-square-figure strong{background:var(--math-green-soft);border:1px solid #cde9d7;border-radius:11px;padding:10px 13px;color:var(--math-green-dark)}
.area-model{display:grid;grid-template-columns:85px 1fr 1fr;max-width:520px;margin:18px auto;border:2px solid #94a3b8;border-radius:12px;overflow:hidden}.area-model>div{padding:13px;text-align:center;border-right:1px solid #cbd5e1;border-bottom:1px solid #cbd5e1;background:#fff;font-weight:800}.area-model .top,.area-model .side{background:linear-gradient(180deg,#ede9fe,#ecfdf5);color:var(--math-purple-dark)}.area-model .corner{background:#f8fafc}.figure-caption{text-align:center;color:#64748b;font-size:.94rem}.product-sum{display:flex;align-items:center;justify-content:center;gap:12px;margin:16px 0}.product-sum>div:not(.pair){background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:10px 14px;text-align:center}.product-sum small{display:block;color:#64748b}.product-sum strong{color:var(--math-purple-dark)}.product-sum .pair{background:var(--math-green-soft);color:var(--math-green-dark);padding:10px 15px;border-radius:999px;font-weight:900}.cross-figure{max-width:420px;margin:16px auto;text-align:center}.cross-figure .toprow,.cross-figure .bottomrow{display:flex;justify-content:space-around;gap:20px}.cross-figure span{background:#fff;border:1px solid #e2e8f0;padding:9px 14px;border-radius:10px}.cross-figure .cross{font-size:1.5rem;color:var(--math-purple);font-weight:900}.cross-note{margin-top:9px;color:var(--math-green-dark);font-weight:850}
@media(max-width:760px){.alg20-grid{grid-template-columns:1fr}.product-sum{flex-direction:column}.area-model{grid-template-columns:65px 1fr 1fr}.math-page-toc ol{grid-template-columns:1fr 1fr}}@media(max-width:520px){.math-page-toc ol{grid-template-columns:1fr}.area-model>div{padding:9px 5px;font-size:.9rem}}


/* Chapter 21 algebraic fraction visuals */
.af-rule-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.af-rule-card{border-radius:16px;padding:16px;background:#f8fafc;border:1px solid #dbe3ee}.af-rule-card.good{border-top:5px solid var(--math-green)}.af-rule-card.bad{border-top:5px solid #b91c1c}.af-rule-card h3{margin-top:0;color:var(--math-purple-dark)}.af-stack{display:grid;gap:8px;text-align:center;background:#fff;border:1px dashed #cbd5e1;border-radius:14px;padding:14px}.af-stack>span:first-child{font-size:1.25rem;font-weight:900}.af-stack .arrow{font-size:.9rem;color:var(--math-green-dark);font-weight:800}.af-stack .arrow.no{color:#991b1b}.af-stack b{color:var(--math-purple-dark);font-size:1.12rem}.af-method-box{background:linear-gradient(135deg,#f5f3ff,#f0fdf4);border:1px solid #d9d6fe;border-radius:16px;padding:16px;margin:16px 0}.af-method-box h3{margin-top:0;color:var(--math-purple-dark)}.af-method-steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}.af-method-steps span{background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:12px}.af-method-steps b{display:grid;place-items:center;width:28px;height:28px;border-radius:9px;background:var(--math-purple-soft);color:var(--math-purple-dark);margin-bottom:8px}.af-factor-figure{display:grid;grid-template-columns:1fr auto 1fr auto;gap:12px;align-items:center;background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;margin:16px 0}.af-factor-figure .before,.af-factor-figure .after{display:grid;gap:8px;background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:12px;text-align:center}.af-factor-figure strong{color:var(--math-purple-dark)}.af-factor-figure span{font-size:1.08rem}.af-factor-figure small{color:#64748b}.factor-arrow{font-weight:900;color:var(--math-green-dark);text-align:center}.af-factor-figure .result{background:var(--math-green-soft);border:1px solid #bde9ca;border-radius:12px;padding:12px;font-weight:900;color:var(--math-green-dark)}.af-common-denom{display:grid;grid-template-columns:1fr auto 1fr auto;gap:12px;align-items:center;background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;margin:16px 0}.af-frac-box{display:grid;gap:8px;text-align:center;background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:12px}.af-frac-box b,.af-frac-box strong{font-size:1.08rem;color:var(--math-purple-dark)}.af-frac-box span{font-size:.9rem;color:#64748b}.af-op{font-size:1.5rem;font-weight:900;color:var(--math-purple-dark)}.af-equals{font-weight:900;color:var(--math-green-dark);text-align:center}.af-denom-figure{display:grid;place-items:center;gap:10px;background:linear-gradient(135deg,#f5f3ff,#f0fdf4);border:1px solid #d9d6fe;border-radius:16px;padding:18px;margin:16px 0}.af-denom-figure>div:first-child{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}.denom-chip{display:inline-block;background:#fff;border:1px solid #d8dee8;border-radius:999px;padding:9px 14px;font-weight:900;color:var(--math-purple-dark)}.af-times{font-size:.92rem;font-weight:800;color:#475569}.af-denom-figure strong{color:var(--math-green-dark)}
@media(max-width:850px){.af-rule-grid{grid-template-columns:1fr}.af-method-steps{grid-template-columns:repeat(2,minmax(0,1fr))}.af-factor-figure,.af-common-denom{grid-template-columns:1fr}.factor-arrow,.af-op,.af-equals{justify-self:center}}
@media(max-width:520px){.af-method-steps{grid-template-columns:1fr}}


/* Chapter 22 index visuals */
.index-law-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:16px 0}.index-law-grid.extended{grid-template-columns:repeat(3,minmax(0,1fr))}.index-law-grid article{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:14px;text-align:center}.index-law-grid h3{margin:.1rem 0 .65rem;color:var(--math-purple-dark);font-size:1rem}.index-law-formula{background:#fff;border:1px solid #e5e7eb;border-radius:12px;padding:10px 7px;font-weight:900;margin-bottom:8px}.index-law-grid p{margin:.35rem 0 0;color:#475569;font-size:.94rem}
.index-visual,.base-rewrite-figure,.equation-index-figure{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.equation-index-figure{grid-template-columns:repeat(2,minmax(0,1fr))}.index-visual>div,.base-rewrite-figure>div,.equation-index-figure>div{display:grid;gap:7px;background:linear-gradient(180deg,#f5f3ff,#f0fdf4);border:1px solid #d9d9e8;border-radius:16px;padding:14px;text-align:center}.index-visual b,.base-rewrite-figure b,.equation-index-figure b{color:var(--math-purple-dark);font-size:1.05rem}.index-visual span,.base-rewrite-figure span,.equation-index-figure span{color:#64748b;font-size:.9rem}.index-visual strong,.base-rewrite-figure strong,.equation-index-figure strong{color:var(--math-green-dark)}
.index-warning{background:#fff7ed;border:1px solid #fed7aa;border-left:5px solid #f59e0b;border-radius:14px;padding:14px 16px;margin:16px 0}.index-warning strong{color:#9a3412}.index-warning div{font-size:1.1rem;font-weight:900;margin:8px 0;color:#7c2d12}.index-warning p{margin:.35rem 0 0}
@media(max-width:900px){.index-law-grid,.index-law-grid.extended{grid-template-columns:repeat(2,minmax(0,1fr))}.index-visual,.base-rewrite-figure{grid-template-columns:1fr}.equation-index-figure{grid-template-columns:1fr}}
@media(max-width:560px){.index-law-grid,.index-law-grid.extended{grid-template-columns:1fr}}


/* Chapter 23 figures */
.equation-figure-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.eq-figure-card,.quadratic-formula-card{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}.eq-figure-card h3{margin-top:0;color:var(--math-purple-dark)}
.formula-flow{display:flex;align-items:center;justify-content:center;gap:12px;flex-wrap:wrap}.formula-flow>div{background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:12px;text-align:center}.formula-flow span{display:block;color:#64748b;margin-top:4px}.formula-final{font-size:1.15rem;font-weight:900;color:var(--math-green-dark)}
.eq-balance-visual{display:grid;grid-template-columns:1fr auto 1fr;gap:14px;align-items:center;margin:16px 0}.balance-side{background:#f8fafc;border:1px solid #dbe3ee;border-bottom:5px solid var(--math-purple);border-radius:15px;padding:16px;text-align:center}.balance-side span{display:block;color:#64748b}.balance-side b{display:block;margin-top:6px;color:var(--math-purple-dark);font-size:1.2rem}.balance-equals{font-size:1.7rem;font-weight:900;color:var(--math-green-dark)}
.balance-diagram{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:8px;margin:16px 0}.balance-diagram svg{width:100%;height:auto;max-height:260px}.balance-diagram line,.balance-diagram path{stroke:#64748b;stroke-width:4;fill:none}.balance-diagram text{fill:#334155;font-size:19px;font-weight:700}
.method-compare{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:16px 0}.method-compare>div{background:#f8fafc;border:1px solid #dbe3ee;border-radius:14px;padding:14px}.method-compare strong{display:block;color:var(--math-purple-dark);margin-bottom:8px}.method-compare span{display:block;background:#fff;border:1px solid #e2e8f0;border-radius:9px;padding:8px;margin:6px 0}
.fraction-clear-figure,.square-completion-figure{display:flex;align-items:stretch;justify-content:center;gap:12px;flex-wrap:wrap;margin:16px 0}.frac-step,.square-completion-figure>div:not(.arrow-big){background:#f8fafc;border:1px solid #dbe3ee;border-radius:14px;padding:14px;min-width:150px;text-align:center}.frac-step span,.square-completion-figure span{display:block;color:#64748b;margin-top:5px}.arrow-big{display:grid;place-items:center;font-size:1.6rem;font-weight:900;color:var(--math-green-dark)}
.sim-figure{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:10px;margin:16px 0}.sim-figure svg{width:100%;max-height:320px}.sim-figure .axis{stroke:#64748b;stroke-width:3}.sim-figure .line-a{stroke:#6d28d9;stroke-width:5}.sim-figure .line-b{stroke:#16a34a;stroke-width:5}.sim-figure circle{fill:#111827}.sim-figure text{fill:#334155;font-size:17px;font-weight:700}.elimination-rule{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:12px 0}.elimination-rule div{background:linear-gradient(180deg,#ede9fe,#dcfce7);border:1px solid #d7d9e2;border-radius:13px;padding:12px;text-align:center}.elimination-rule strong,.elimination-rule span{display:block}.elimination-rule strong{color:var(--math-purple-dark)}
.zero-product-figure{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;text-align:center;margin:16px 0}.zero-product-figure>div:first-child{font-size:1.2rem;font-weight:900;color:var(--math-purple-dark)}.zero-product-figure>span{display:block;color:#64748b;margin:8px 0}.root-pair{display:flex;justify-content:center;gap:10px;flex-wrap:wrap}.root-pair b{background:#fff;border:1px solid #e2e8f0;border-radius:10px;padding:9px 12px}.zero-product-figure>strong{display:block;margin-top:10px;color:var(--math-green-dark)}
.quadratic-formula-card{text-align:center;margin:16px 0}.qf-main{font-size:1.15rem}.qf-labels{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.qf-labels span{background:#fff;border:1px solid #e2e8f0;border-radius:10px;padding:8px;color:#475569}
.rearrange-ladder{display:flex;align-items:center;justify-content:center;gap:8px;flex-wrap:wrap;margin:16px 0}.rearrange-ladder div{background:#f8fafc;border:1px solid #dbe3ee;border-radius:12px;padding:10px 12px;font-weight:800;color:var(--math-purple-dark)}.rearrange-ladder span{font-size:.86rem;color:var(--math-green-dark);font-weight:800}
.hard-subject-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:16px 0}.hard-subject-grid article{background:#f8fafc;border:1px solid #dbe3ee;border-radius:14px;padding:14px}.hard-subject-grid strong,.hard-subject-grid span{display:block}.hard-subject-grid strong{color:var(--math-purple-dark);margin-bottom:6px}.hard-subject-grid span{margin:4px 0;color:#475569}
.alg-frac-flow{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:16px 0}.alg-frac-flow div{background:#f8fafc;border:1px solid #dbe3ee;border-top:5px solid var(--math-purple);border-radius:14px;padding:12px;text-align:center}.alg-frac-flow strong{display:grid;place-items:center;width:30px;height:30px;margin:0 auto 7px;border-radius:50%;background:var(--math-green-soft);color:var(--math-green-dark)}.alg-frac-flow span{font-size:.92rem;color:#475569}
@media(max-width:820px){.equation-figure-grid,.method-compare,.elimination-rule,.hard-subject-grid{grid-template-columns:1fr}.qf-labels,.alg-frac-flow{grid-template-columns:repeat(2,1fr)}}
@media(max-width:520px){.eq-balance-visual{grid-template-columns:1fr}.balance-equals{text-align:center}.qf-labels,.alg-frac-flow{grid-template-columns:1fr}.fraction-clear-figure,.square-completion-figure{display:grid;grid-template-columns:1fr}.arrow-big{transform:rotate(90deg)}}

/* Chapter 24 textbook figures */
.book-figure{margin:18px auto 22px;background:#f8fafc;border:1px solid #dbe3ee;border-radius:17px;padding:14px;text-align:center;box-shadow:0 4px 12px rgba(15,23,42,.04);max-width:720px}
.book-figure img{display:block;max-width:100%;height:auto;margin:0 auto;border-radius:8px}
.book-figure figcaption{margin-top:11px;color:#475569;font-size:.94rem;line-height:1.5;text-align:left}
.book-figure.wide{max-width:820px}.book-figure.narrow{max-width:430px}.book-figure.compact{max-width:310px}
@media(max-width:560px){.book-figure{padding:10px;margin:14px auto 18px}.book-figure figcaption{font-size:.9rem}}


/* Chapter 25 sequence figures */
.sequence-strip{display:flex;align-items:center;justify-content:center;gap:8px;flex-wrap:wrap;background:#f8fafc;border:1px solid #dbe3ee;border-radius:15px;padding:14px;margin:12px 0}
.sequence-strip span{min-width:46px;text-align:center;background:#fff;border:2px solid #d8d1f3;border-radius:10px;padding:8px 9px;font-weight:900;color:var(--math-purple-dark)}
.sequence-strip b{color:var(--math-green-dark);font-size:.92rem}
.nth-grid{display:grid;gap:4px;margin:16px 0;border:1px solid #dbe3ee;border-radius:15px;overflow:hidden;background:#fff}
.nth-grid>div{display:grid;grid-template-columns:minmax(150px,1.4fr) repeat(5,1fr);gap:1px;background:#dbe3ee}
.nth-grid b,.nth-grid span{background:#fff;padding:11px;text-align:center}.nth-grid b{background:#f3f0ff;color:var(--math-purple-dark)}
@media(max-width:620px){.nth-grid{overflow-x:auto}.nth-grid>div{min-width:560px}.sequence-strip{justify-content:flex-start;overflow-x:auto;flex-wrap:nowrap}}


/* Chapter 26 proportion visuals */
.proportion-compare{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}
.proportion-compare article,.formula-flow>div,.prop-rule-grid article{background:#f8fafc;border:1px solid #dbe3ee;border-radius:16px;padding:16px;box-shadow:0 4px 12px rgba(15,23,42,.04)}
.proportion-compare h3{margin-top:0;color:var(--math-purple-dark)}
.prop-arrow{display:grid;grid-template-columns:1fr auto 1fr;gap:8px;align-items:center;margin:8px 0}
.prop-arrow span{background:#fff;border:1px solid #e2e8f0;border-radius:12px;padding:9px;text-align:center;font-weight:900;color:var(--math-purple-dark)}
.prop-arrow b{background:var(--math-green-soft);border:1px solid #cde9d7;border-radius:999px;padding:6px 9px;color:var(--math-green-dark)}
.prop-arrow.inverse b{background:var(--math-purple-soft);border-color:#ddd6fe;color:var(--math-purple-dark)}
.formula-flow{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0}.formula-flow>div{display:grid;grid-template-columns:auto 1fr auto 1fr;align-items:center;gap:10px}.formula-flow strong{color:var(--math-green-dark)}.formula-flow span{font-size:1.08rem;font-weight:800;text-align:center}.formula-flow b{font-size:1.3rem;color:var(--math-purple-dark)}
.prop-rule-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.prop-rule-grid article{text-align:center}.prop-rule-grid strong{display:block;color:var(--math-purple-dark);margin-bottom:6px}.multiplier-table-wrap{margin:18px 0}
@media(max-width:850px){.proportion-compare,.formula-flow,.prop-rule-grid{grid-template-columns:1fr}.formula-flow>div{grid-template-columns:1fr;justify-items:center}.formula-flow b{transform:rotate(90deg)}}


/* Chapter 27 textbook graph figures */
.book-figure{margin:18px auto;max-width:620px;background:#fff;border:1px solid #dce5ef;border-radius:16px;padding:14px;box-shadow:0 4px 14px rgba(15,23,42,.05);text-align:center}.book-figure.wide{max-width:720px}.book-figure.small{max-width:430px}.book-figure img{display:block;max-width:100%;height:auto;margin:0 auto;border-radius:8px}.book-figure figcaption{margin-top:10px;color:#475569;font-size:.95rem;line-height:1.45;text-align:left}.book-figure-pair{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;align-items:start;margin:16px 0}.book-figure-pair .book-figure{margin:0;max-width:none;height:100%}.graph-meaning-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:16px 0}.graph-meaning-grid div{background:#f8fafc;border:1px solid #e2e8f0;border-radius:13px;padding:12px}.graph-meaning-grid strong{display:block;color:var(--math-purple-dark);margin-bottom:4px}.graph-meaning-grid span{color:#475569}@media(max-width:720px){.book-figure-pair,.graph-meaning-grid{grid-template-columns:1fr}.book-figure{padding:10px}}

/* Chapter 32 geometry vocabulary */
.geometry-term-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:16px 0}.geometry-term-grid div{background:#f8fafc;border:1px solid #e2e8f0;border-radius:13px;padding:12px}.geometry-term-grid strong{display:block;color:var(--math-purple-dark);margin-bottom:4px}.geometry-term-grid span{color:#475569}.math-rule-row{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:16px 0}.math-rule-row>div{background:#f8fafc;border:1px solid #e2e8f0;border-radius:14px;padding:14px}.math-rule-row strong{display:block;color:var(--math-purple-dark);margin-bottom:5px}@media(max-width:800px){.geometry-term-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:520px){.geometry-term-grid,.math-rule-row{grid-template-columns:1fr}}


/* Chapter 35 similarity table */
.scale-factor-table-wrap{overflow-x:auto;margin:16px 0 20px}.scale-factor-table-wrap .math-table{min-width:520px}.scale-factor-table-wrap .math-table th:first-child,.scale-factor-table-wrap .math-table td:first-child{text-align:left}