*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:#f5f8f5;color:#214c50;font:16px/1.65 Arial,sans-serif}a{color:#166d5e;text-underline-offset:3px}a:hover{text-decoration-thickness:2px}button,input{font:inherit}button,a{touch-action:manipulation}a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid #996000;outline-offset:4px}.site-header{max-width:1260px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:22px 28px;gap:22px}.top-nav{display:flex;flex-wrap:wrap;gap:22px}.top-nav a{font-size:14px;font-weight:bold;text-decoration:none}.notice{background:#fff2dc;color:#674718;text-align:center;padding:9px 20px;font-size:13px}.layout{max-width:1260px;margin:auto;padding:30px 28px 65px;display:grid;grid-template-columns:240px minmax(0,1fr);gap:38px}.browse{position:sticky;top:20px;border:1px solid #c9ddd6;border-radius:12px;padding:18px;background:white}.browse 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0}.section{margin-top:30px;padding:25px 28px;background:white;border:1px solid #d2e3db;border-radius:12px}.section p{max-width:740px}.listing{list-style:none;padding:0}.listing li{border-top:1px solid #dfebe5;padding:18px 0;display:flex;justify-content:space-between;gap:20px}.listing small{display:block;color:#4c6863}.meta{display:flex;flex-wrap:wrap;gap:10px;font-size:13px}.meta span{padding:4px 10px;border:1px solid #c9ddd6;border-radius:5px}.concept{display:grid;grid-template-columns:1fr 1fr;gap:22px}.model{padding:20px;background:#f0f7f3;border-radius:9px}.rod{display:inline-block;width:14px;height:75px;margin:3px;background:repeating-linear-gradient(to bottom,#258576 0px,#258576 6px,#d6eee6 6px,#d6eee6 7.5px);border:1px solid #176e5c}.ones{display:grid;grid-template-columns:repeat(6,17px);gap:5px;margin:15px 0}.one{width:17px;height:17px;background:#edb64d;border:1px solid #986116}.note{padding:15px 20px;border-left:4px solid #db7950;background:#fff7e9}.controls{display:flex;flex-wrap:wrap;align-items:center;gap:12px;padding:18px 0}.controls label{display:flex;align-items:center;gap:7px}.controls input{width:20px;height:20px}fieldset{border:0;padding:0;margin:0}.sheet{color:#183b40;background:white;border:1px solid #bfcfc9;padding:24px;max-width:760px;margin:15px auto}.sheet h2{font-size:22px;margin:4px 0}.sheet-top{border-bottom:2px solid #176e5c;padding-bottom:14px}.sheet-meta{display:flex;justify-content:space-between;gap:12px;font-size:13px;margin:16px 0}.questions{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.question{display:flex;gap:12px;padding:8px 0}.number{font-size:12px;color:#4c6863}.sum{font-size:25px;line-height:1.3;width:100px;text-align:right;font-variant-numeric:tabular-nums;letter-spacing:3px}.bottom-number{border-bottom:2px solid #214c50;display:flex;justify-content:space-between}.answer-space{margin-top:6px;height:42px;min-width:88px;border:1.5px solid #426e6d;border-radius:3px;letter-spacing:2px;padding-right:5px}.answer{color:#155845;font-weight:bold}.sheet-foot{margin-top:22px;font-size:11px;border-top:1px solid #bfcfc9;padding-top:8px}.status{font-size:13px;min-height:24px}footer{border-top:1px solid #c9ddd6;max-width:1204px;margin:auto;padding:25px;font-size:13px}#print-root{display:none}.skip{position:absolute;left:-9999px}.skip:focus{left:10px;top:10px;background:white;padding:10px;z-index:10}@media(max-width:760px){.layout{grid-template-columns:1fr;padding:20px 16px;gap:18px}.browse{position:static}.site-header{padding:16px;flex-wrap:wrap}.top-nav{gap:14px}.section{padding:20px 16px}.concept{grid-template-columns:1fr}.questions{grid-template-columns:repeat(2,1fr);gap:15px}.sheet{padding:15px}.sum{width:87px;font-size:23px}.listing li{display:block}.meta{gap:5px}}@media print{@page{size:A4;margin:0}body{background:white;margin:0;print-color-adjust:exact;-webkit-print-color-adjust:exact}body>*:not(#print-root){display:none!important}#print-root{display:block}.sheet{border:0;margin:0;padding:12mm;width:100%;height:270mm;max-width:none;break-after:page;overflow:hidden}.sheet:last-child{break-after:auto}.questions{grid-template-columns:repeat(3,1fr);gap:7mm}.question{break-inside:avoid}.sheet h2{font-size:20px}.sheet-meta{margin:5mm 0}.sheet-foot{margin-top:6mm}}

[hidden]{display:none!important}.filter-row{display:flex;gap:16px;flex-wrap:wrap;margin:20px 0}.filter-row label{display:grid;gap:6px;font-weight:bold;font-size:14px}.filter-row select{padding:10px;border:1px solid #9dbbb0;border-radius:6px;color:#214c50;background:white;max-width:100%;font:inherit}.library-block{margin-top:24px}.library-block h3{margin-bottom:4px}.skill-label{font-size:12px;display:inline-block;padding:2px 7px;border:1px solid #c9ddd6;border-radius:4px;margin:6px 0}.browse .group h2{font-size:13px}.browse .choices{display:grid;grid-template-columns:1fr;gap:7px}.browse .choice{display:block;padding:10px 12px;border:1px solid #bfd8d7;border-radius:6px;text-decoration:none}.browse .choice .example{display:inline-block;min-width:23px;font-weight:bold}.browse .choice[aria-current=page]{background:#e5f2ec;border-color:#176e5c}.browse .choice small{display:block;color:#48695f}.standards{font-size:13px;color:#48695f}.regroup-space{height:20px}.answer-space{display:block}.equation{display:flex;align-items:center;gap:10px;font-size:23px;white-space:nowrap}.horizontal-question,.fraction-question{flex:1;min-width:0}.horizontal-question .answer-space{width:95px;margin:12px 0}.working-space{display:block;min-height:15px}.fraction{display:inline-flex;vertical-align:middle;flex-direction:column;align-items:center;line-height:1.2;min-width:25px}.fraction>span:first-child{border-bottom:1.5px solid #214c50;padding:0 4px 3px;width:100%;text-align:center}.fraction>span:last-child{padding-top:3px}.fraction-answer{border:1.5px solid #426e6d;border-radius:3px;min-width:90px;width:95px;height:62px;margin-top:12px;text-align:center;display:flex;align-items:center;justify-content:center;font-size:23px}.sheet[data-layout=fractions] .questions,.sheet[data-layout=horizontal] .questions{grid-template-columns:repeat(3,1fr);gap:15px}.sheet[data-layout=pictures] .questions{grid-template-columns:1fr;gap:10px}.sheet[data-layout=pictures] .question{border-bottom:1px dashed #c9ddd6;padding:8px 0 12px}.picture-question{flex:1;min-width:0}.picture-question p{margin:0 0 6px;font-size:13px}.two-baskets{display:grid;grid-template-columns:1fr 1fr;gap:14px}.two-baskets>div{border:1px solid #c9ddd6;border-radius:6px;padding:7px}.picture-count{display:flex;flex-wrap:wrap;gap:4px}.object-icon{width:27px;height:27px}.picture-equation{display:flex;align-items:center;gap:10px;margin-top:9px;font-size:22px}.picture-equation .answer-space{min-width:60px;width:64px;text-align:center;height:38px;min-height:38px}.bar-model{display:grid;grid-template-columns:repeat(8,1fr);max-width:400px;height:48px;margin:16px 0}.bar-model span{border:1px solid #426e6d;background:white}.bar-model .part-a{background:#258576}.bar-model .part-b{background:#edb64d}.sample-equation{font-size:26px;font-weight:bold;padding:14px 0}.visual-caption{font-size:13px}.sheet button:disabled{cursor:not-allowed}button:disabled{opacity:.5;cursor:not-allowed}@media(max-width:760px){.filter-row{display:grid;grid-template-columns:1fr}.filter-row select{width:100%;min-width:0}.sheet[data-layout=fractions] .questions,.sheet[data-layout=horizontal] .questions{grid-template-columns:repeat(2,1fr)}.equation{font-size:20px;gap:7px}.sheet[data-layout=pictures] .sheet-meta{flex-wrap:wrap}.picture-equation{gap:7px}.picture-equation .answer-space{min-width:50px;width:54px}}
@media print{.sheet[data-layout=fractions] .questions,.sheet[data-layout=horizontal] .questions{grid-template-columns:repeat(3,1fr);gap:6mm}.sheet[data-layout=pictures] .questions{grid-template-columns:1fr;gap:2mm}.sheet[data-layout=pictures] .question{padding:2mm 0}.sheet-instruction{margin:3mm 0}.sheet[data-layout=pictures] .object-icon{width:26px;height:26px}.sheet[data-layout=pictures] .picture-equation{margin-top:2mm}.sheet[data-layout=pictures] .sheet-foot{margin-top:3mm}}

/* Missing addends need a writable space inside the equation. */
.sheet[data-layout=missing] .questions{grid-template-columns:repeat(2,minmax(0,1fr))}
.missing-question{min-width:0;flex:1}.missing-question .equation{gap:8px}
.sheet .missing-question .answer-space{min-width:64px;width:64px;margin:0;flex-shrink:0}
.sheet .missing-question .working-space{min-height:26px}
.bar-model span{display:flex;align-items:center;justify-content:center;font-weight:bold;color:#183b40}
@media screen and (max-width:760px){.sheet[data-layout=missing] .questions{grid-template-columns:1fr}}

/* User-approved visual worksheet picker; keep topic/grade navigation unchanged. */
.worksheet-gallery{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin:22px 0 0}
.worksheet-gallery li{display:flex;flex-direction:column;justify-content:flex-start;gap:0;padding:0;border:1px solid #c9ddd6;border-radius:8px;overflow:hidden;min-width:0;background:#fff}
.worksheet-preview{display:block;padding:12px;background:#eef3ef;border-bottom:1px solid #d2e3db}
.worksheet-preview img{display:block;width:100%;height:auto;aspect-ratio:612/789;object-fit:contain;box-shadow:0 2px 6px #214c5020;background:#fff}
.worksheet-preview:hover{background:#e2eee7}.worksheet-preview:focus-visible{outline-offset:-4px}
.worksheet-details{padding:16px;display:flex;flex-direction:column;flex:1;align-items:flex-start}
.worksheet-details h3{font-size:17px;line-height:1.4;margin:7px 0 10px;overflow-wrap:anywhere}
.worksheet-details p{font-size:14px;line-height:1.6;margin:0 0 14px}
.worksheet-details small{font-size:12px;margin-top:auto}
.worksheet-details .skill-label{margin:0;font-size:11px}
@media(max-width:1100px){.worksheet-gallery{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:600px){.worksheet-gallery{grid-template-columns:1fr;gap:22px}.worksheet-details h3{font-size:18px}.worksheet-preview{padding:14px}}

.equal-groups-model{display:flex;flex-wrap:wrap;gap:14px;margin:18px 0}.equal-group{display:grid;grid-template-columns:repeat(3,17px);gap:7px;border:1px solid #426e6d;border-radius:8px;padding:14px;background:white}

.sheet[data-layout=stories] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.story-question{min-width:0;flex:1}.story-prompt{display:block;white-space:normal;line-height:1.5;margin:0 0 12px}
.story-response{display:flex;flex-direction:column;gap:4px;font-size:13px}
.story-response .answer-space{width:120px;margin:0 0 7px}.story-response .story-equation-box{width:100%;min-height:44px}
@media screen and (max-width:760px){.sheet[data-layout=stories] .questions{grid-template-columns:1fr}}

/* Put the answer label beside its box, retaining both writing areas. */
.story-response{display:grid;grid-template-columns:auto minmax(0,1fr);gap:6px 10px;align-items:center}
.story-response>span:first-child,.story-response>.story-equation-box{grid-column:1/-1}
.story-response .answer-space{margin:0}.story-response>.answer-space:last-child{max-width:100%}

.story-response>.story-wide-label{grid-column:1/-1}

/* Reuse the source choices and part-whole relationships in the shared story frame. */
.story-choices{display:flex;flex-wrap:wrap;gap:6px 9px;align-items:center;margin:0 0 12px;font-size:var(--problem-number-size,17px)}
.choice-instruction{flex-basis:100%;font-size:13px}.story-choice{display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:3px 8px;border:2px solid transparent;border-radius:24px;white-space:nowrap}.story-choice.correct-choice{border-color:#c01823;color:#c01823;font-weight:800}
.story-bar-model{margin:12px 0 14px;font-size:var(--problem-number-size,17px);line-height:1.2;max-width:380px}
.bar-whole{display:flex;align-items:center;justify-content:center;gap:12px;min-height:48px;border:1.5px solid #426e6d;margin-bottom:5px;padding:4px}
.bar-label{font-size:13px}.bar-parts{display:grid;grid-template-columns:1fr 1fr;border:1.5px solid #426e6d;min-height:50px}
.bar-part{display:flex;align-items:center;justify-content:center;padding:4px;min-width:0}.bar-part+.bar-part{border-left:1.5px solid #426e6d}
.sheet .story-bar-model .bar-blank{width:76px;min-width:60px;min-height:42px;margin:0}.bar-value{display:flex;align-items:center;justify-content:center;min-height:42px}
@media print{.story-choice.correct-choice{print-color-adjust:exact;-webkit-print-color-adjust:exact}}

.sheet[data-layout=story-pairs] .questions{grid-template-columns:1fr;gap:22px}
.story-pair{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;width:100%}.paired-story{min-width:0}.pair-label{display:block;font-size:14px;margin:0 0 5px}
.story-pair .paired-story+.paired-story{border-left:1px solid #b6cfc5;padding-left:18px}
@media screen and (max-width:760px){.story-pair{grid-template-columns:1fr;gap:18px}.story-pair .paired-story+.paired-story{border-left:0;border-top:1px solid #b6cfc5;padding:16px 0 0}}

.story-explanation{margin-top:12px}.explanation-label{display:block;font-size:13px;margin-bottom:6px}
.sheet .story-explanation .explanation-space{width:100%;min-height:92px;margin:0;padding:5px 8px}
.story-explanation small{display:block;font-size:11px;line-height:1.3;margin-top:5px}
.sheet[data-mode=questions] .explanation-space{background:repeating-linear-gradient(to bottom,transparent 0,transparent 27px,#b6cfc5 27px,#b6cfc5 28px);background-origin:content-box}

.story-response.reason-response{grid-template-columns:minmax(0,1fr) 72px;gap:6px 10px}.story-response.reason-response>span{grid-column:auto}.story-response.reason-response>.answer-space{width:100%;min-height:44px}

.story-calculation{margin-top:10px;font-size:13px}.calculation-space{min-height:90px;margin-top:5px;border-bottom:1px solid #b6cfc5}
.area-products{width:100%;border-collapse:collapse;margin:18px 0;font-size:clamp(12px,2vw,16px)}.area-products caption{text-align:left;margin-bottom:8px}.area-products th,.area-products td{border:1px solid #89aaa4;padding:8px;text-align:center}.area-products th{background:#e7f3ef}

/* Keep long worksheet names inside the mobile content column. */
.layout>main,.layout>aside{min-width:0}@media(max-width:760px){.layout{grid-template-columns:minmax(0,1fr)}}

.division-answers{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:10px;font-size:13px}.division-answers>div{min-width:0}.division-answers>div>span:first-child{display:block;min-height:22px;line-height:1.4}.sheet .division-answers .answer-space{width:100%;margin:0;min-width:0}

.story-response.division-equation>span:first-child,.story-response.division-equation>.story-equation-box{grid-column:auto}.story-response.division-equation{grid-template-columns:auto minmax(0,1fr)}

.story-response.fraction-story-response{grid-template-columns:minmax(0,1fr) 96px;align-items:stretch}.story-response.fraction-story-response>span{grid-column:auto}.sheet .fraction-story-response>.answer-space{height:76px;min-height:76px;width:100%;min-width:0}.fraction-story-equation{display:inline-flex;align-items:center;justify-content:center;gap:6px;flex-wrap:wrap}

.operation-menu{border-top:1px solid #d2e3db;padding:10px 0}.browse .operation-menu summary{font-size:15px;line-height:1.5}.operation-menu summary>span{color:#176e5c;font-weight:800;margin-right:4px}.browse .operation-menu ul{margin:8px 0 0 10px}.browse .operation-menu li>a,.category-pending{font-size:13px;line-height:1.4;padding:9px 8px;display:block}.operation-menu small{font-size:11px;display:block;color:#4c6863;margin-top:3px}.category-pending{color:#536864}.browse .operation-menu a[aria-current=true]{background:#e5f2ec;font-weight:bold}

/* Preserve aligned decimal columns without reducing handwriting or answer sizes. */
.sheet[data-number-domain=decimal][data-layout=vertical] .sum{width:120px;letter-spacing:0;font-kerning:none;font-variant-numeric:tabular-nums}
@media screen and (max-width:440px){.sheet[data-number-domain=decimal][data-layout=vertical] .questions{grid-template-columns:1fr}}
.place-value-table{border-collapse:collapse;width:100%;max-width:440px;font-variant-numeric:tabular-nums}.place-value-table th,.place-value-table td{padding:8px 6px;text-align:right;border-bottom:1px solid #9bbeb2}.place-value-table caption{text-align:left;font-weight:bold;margin-bottom:8px}.place-value-table th:first-child,.place-value-table td:first-child{text-align:left}

.sheet[data-layout=early-pictures] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.early-picture-question{min-width:0;width:100%}.early-picture-question>p{font-size:14px;line-height:1.4;margin:0 0 9px;min-height:40px}.early-picture-model{display:flex;align-items:center;gap:8px;min-height:60px;margin-bottom:12px}.early-picture-group{display:flex;align-items:center;gap:4px;flex-wrap:wrap;min-height:46px;min-width:34px}.early-object{display:inline-flex;position:relative}.early-object .object-icon{width:30px;height:30px}.early-object.crossed-out:after{content:"";position:absolute;left:0;right:0;top:48%;height:3px;background:#c01823;transform:rotate(-45deg)}.empty-group{border:1px dashed #426e6d;min-width:34px;text-align:center}.early-picture-question .equation{flex-wrap:wrap;gap:6px}.early-picture-question .answer-space{margin:0;min-width:66px;width:76px;height:44px}.sheet[data-layout=early-pictures]{--problem-number-size:23px}
@media screen and (max-width:760px){.sheet[data-layout=early-pictures] .questions{grid-template-columns:1fr}}

.sheet[data-layout=early-activities] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.early-activity-question{width:100%;min-width:0}.early-activity-question>p{font-size:14px;line-height:1.4;min-height:40px;margin:0 0 12px}.early-activity-question .picture-count{gap:6px;min-height:50px;align-content:center}.early-activity-question .object-icon{width:32px;height:32px}.early-activity-question .activity-answer{font-size:23px;flex-wrap:wrap;margin-top:15px}.early-activity-question .answer-space{width:76px;min-width:76px;height:44px;margin:0}.sheet[data-layout=early-activities]{--problem-number-size:23px}
@media screen and (max-width:760px){.sheet[data-layout=early-activities] .questions{grid-template-columns:1fr}}

.circle-activity .picture-count{gap:12px;justify-content:flex-start}.mark-object{width:44px;height:44px;display:inline-flex;align-items:center;justify-content:center;flex:none;border:2px solid transparent;border-radius:50%;box-sizing:border-box}.mark-object.marked-example{border-color:#c01823}.circle-activity>p.equation{font-size:23px;line-height:1.4;display:block;white-space:normal}.circle-activity .mark-key-note{font-size:13px;line-height:1.4;margin:12px 0 0;min-height:0}.circle-activity .activity-answer{margin-top:8px}

.sheet[data-layout=number-words] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.number-word-activity{width:100%;min-width:0}.number-word-activity>p{font-size:14px;line-height:1.4;margin:0 0 12px;white-space:normal}.number-word-board{position:relative;width:100%;height:180px}.matching-lines{position:absolute;inset:0;width:100%;height:180px;overflow:visible}.matching-dot{position:absolute;width:6px;height:6px;border-radius:50%;background:#214c50;transform:translate(-50%,-50%)}.matching-line{stroke:#c01823;stroke-width:2;vector-effect:non-scaling-stroke}.matching-number,.matching-word{position:absolute;transform:translateY(-50%);font-size:23px;line-height:1.3;white-space:nowrap}.matching-number{left:0;width:20%;text-align:center}.matching-word{left:65%;width:35%;text-align:left}.matching-key .matching-word{color:#c01823;font-weight:700}
@media screen and (max-width:1100px){.sheet[data-layout=number-words] .questions{grid-template-columns:1fr}}

.sheet[data-layout=number-order]{--problem-number-size:23px}.sheet[data-layout=number-order] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.number-order-activity{width:100%;min-width:0}.number-order-activity .equation{font-size:23px}.order-cards{display:flex;gap:12px;align-items:center}.order-card{display:inline-flex;align-items:center;justify-content:center;width:52px;height:46px;border:1px solid #426e6d;border-radius:6px;background:#f5f8f5}.number-order-activity>p{font-size:13px;line-height:1.4;margin:12px 0 7px}.order-response{display:flex;align-items:center;gap:5px}.order-response .answer-space{width:52px;min-width:44px;max-width:58px;flex:1;height:48px;margin:0}.order-arrow{font-size:16px;flex:none}
@media screen and (max-width:1100px){.sheet[data-layout=number-order] .questions{grid-template-columns:1fr}}

.sheet[data-layout=number-neighbors]{--problem-number-size:23px}.sheet[data-layout=number-neighbors] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.number-neighbor-activity{width:100%;min-width:0}.number-neighbor-row.equation{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;max-width:268px;font-size:23px}.neighbor-cell{display:flex;flex-direction:column;align-items:center;gap:10px;min-width:0}.neighbor-label{font-size:13px;line-height:1.4}.neighbor-given{display:inline-flex;align-items:center;justify-content:center;border:1px solid #426e6d;background:#f5f8f5;border-radius:6px;width:100%;max-width:58px;height:48px}.neighbor-cell .answer-space{width:100%;min-width:44px;max-width:58px;height:48px;margin:0}
@media screen and (max-width:1100px){.sheet[data-layout=number-neighbors] .questions{grid-template-columns:1fr}}

.sheet[data-layout=number-line]{--problem-number-size:23px}.sheet[data-layout=number-line] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.number-line-activity{width:100%;min-width:0}.number-line-activity>p{font-size:13px;line-height:1.4;margin:0 0 12px;white-space:normal}.number-line-axis{display:block;width:100%;height:24px;overflow:visible}.number-line-axis path{fill:none;stroke:#426e6d;stroke-width:1.5;vector-effect:non-scaling-stroke}.number-line-values.equation{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:0;font-size:23px;margin-top:4px;height:48px}.number-line-value{display:flex;align-items:center;justify-content:center;min-width:0}.number-line-value .answer-space{width:48px;min-width:48px;height:48px;margin:0}.number-line-known{line-height:1.3}
@media screen and (max-width:1100px){.sheet[data-layout=number-line] .questions{grid-template-columns:1fr}}

/* Drawing space for the reused ten-frame activity. */
.sheet[data-layout=ten-frame]{--problem-number-size:23px}
.sheet[data-layout=ten-frame] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.ten-frame-activity{width:100%;min-width:0}.ten-frame-activity>p{font-size:13px;line-height:1.4;margin:0 0 16px;white-space:normal}
.ten-frame-activity .ten-frame{display:grid;grid-template-columns:repeat(5,44px);grid-template-rows:repeat(2,44px);width:220px;border:1px solid #426e6d;margin:0 0 20px}
.ten-frame-activity .ten-frame>span{display:flex;align-items:center;justify-content:center;border:1px solid #426e6d;min-width:0}
.ten-frame-activity .ten-frame img{width:32px;height:32px;object-fit:contain}
.ten-frame-added{display:block;width:20px;height:20px;border:3px solid #c01823;border-radius:50%;box-sizing:border-box}
.ten-frame-equation.equation{display:flex;align-items:center;gap:8px;font-size:23px;white-space:nowrap}
.ten-frame-equation .answer-space{width:56px;min-width:56px;height:48px;margin:0}
.ten-frame-activity>small{display:block;margin-top:14px;font-size:12px;line-height:1.4;white-space:normal}
@media screen and (max-width:1100px){.sheet[data-layout=ten-frame] .questions{grid-template-columns:1fr}}

.sheet[data-layout=make-ten-missing]{--problem-number-size:23px}
.sheet[data-layout=make-ten-missing] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.make-ten-missing .equation{font-size:23px;display:flex;align-items:center;gap:8px;white-space:nowrap}
.sheet .make-ten-missing .answer-space{width:56px;min-width:56px;height:48px;margin:0}
.make-ten-missing .drawing-label{font-size:12px;line-height:1.4;margin:18px 0 9px;white-space:normal}
.make-ten-drawing{min-height:135px;border:1px dashed #678b86;border-radius:3px}
@media screen and (max-width:1100px){.sheet[data-layout=make-ten-missing] .questions{grid-template-columns:1fr}}

.sheet[data-layout=length-compare]{--problem-number-size:23px}
.sheet[data-layout=length-compare] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}
.length-activity{min-width:0;width:100%}.length-activity>p{font-size:13px;line-height:1.4;white-space:normal;margin:0 0 8px}
.length-activity svg{width:100%;max-width:270px;height:auto;display:block;margin:0 0 10px}
.length-activity .equation{font-size:23px;display:flex;align-items:center;gap:10px}
.length-activity .answer-space{min-width:56px;width:56px;height:48px;margin:0}
@media screen and (max-width:1100px){.sheet[data-layout=length-compare] .questions{grid-template-columns:1fr}}

.length-activity svg rect{stroke:#426e6d;stroke-width:1.5}
.length-activity svg rect.longer-answer{stroke:#c01823;stroke-width:3}

.sheet[data-layout=shape-count]{--problem-number-size:23px}
.sheet[data-layout=shape-count] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.shape-count-activity{width:100%;min-width:0}.shape-count-activity>p{font-size:14px;line-height:1.4;margin:0 0 14px;white-space:normal}
.shape-items{display:flex;flex-wrap:wrap;gap:6px;max-width:294px;margin-bottom:18px;align-content:flex-start;min-height:144px}
.shape-item{width:44px;height:44px;flex:none;display:inline-flex;align-items:center;justify-content:center;border:2px solid transparent;border-radius:50%;font:40px/1 Arial,sans-serif;color:#183b40}
.shape-item.selected-shape{border-color:#c01823}
.shape-count-activity .equation{display:flex;gap:10px;align-items:center;font-size:23px;white-space:normal;flex-wrap:wrap}
.shape-count-activity .answer-space{width:56px;min-width:56px;height:48px;margin:0}
@media screen and (max-width:1100px){.sheet[data-layout=shape-count] .questions{grid-template-columns:1fr}}

.sheet[data-layout=flat-shapes],.sheet[data-layout=shape-sides]{--problem-number-size:23px}
.sheet[data-layout=flat-shapes] .questions,.sheet[data-layout=shape-sides] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}
.flat-shape-activity{width:100%;min-width:0;display:flex;flex-direction:column;align-items:center;gap:12px}
.flat-shape-picture{width:116px;height:116px}.flat-shape-picture svg{display:block;width:116px;height:116px}.flat-shape-picture circle,.flat-shape-picture polygon{stroke:#426e6d;stroke-width:1.5}
.flat-shape-activity .equation{font-size:23px;display:flex;justify-content:center;width:100%}
.flat-shape-activity .answer-space{width:164px;min-width:164px;height:48px;margin:0;letter-spacing:0}
@media screen and (max-width:1100px){.sheet[data-layout=flat-shapes] .questions,.sheet[data-layout=shape-sides] .questions{grid-template-columns:1fr}}

.sheet[data-layout=shape-sides] .flat-shape-activity{gap:6px}.sheet[data-layout=shape-sides] .equation{flex-direction:column;align-items:center;gap:5px}.side-count-label{font-size:13px;line-height:1.4}.sheet[data-layout=shape-sides] .answer-space{width:56px;min-width:56px;height:48px}

.sheet[data-layout=repeating-patterns]{--problem-number-size:40px}
.sheet[data-layout=repeating-patterns] .questions{grid-template-columns:1fr;gap:20px}
.repeating-pattern-activity{width:100%;min-width:0}.pattern-row.equation{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:40px;white-space:normal}
.pattern-shape{display:inline-flex;align-items:center;justify-content:center;width:44px;height:56px;flex:none;font:40px/1 Arial,sans-serif;color:#183b40}
.pattern-row .answer-space{width:64px;min-width:64px;height:64px;flex:none;margin:0;letter-spacing:0}
.repeating-pattern-activity>p{font-size:13px;line-height:1.4;margin:14px 0 0;white-space:normal}

.sheet[data-layout=number-bonds]{--problem-number-size:23px}.sheet[data-layout=number-bonds] .questions{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.number-bond-activity{width:100%;min-width:0}.number-bond-activity>p{font-size:14px;line-height:1.4;white-space:normal;margin:0 0 12px;min-height:40px}
.number-bond-activity .picture-count{display:flex;flex-wrap:wrap;gap:6px;max-width:244px;min-height:94px;margin-bottom:10px}.number-bond-activity .object-icon{width:32px;height:32px}.number-bond-activity .marked-example{border-color:#c01823}
.bond-diagram.equation{display:block;position:relative;width:200px;height:132px;font-size:23px;white-space:normal;margin:0 auto}.bond-diagram svg{position:absolute;inset:0;width:200px;height:132px}.bond-diagram path{stroke:#426e6d;stroke-width:1.5;fill:none}
.bond-known{position:absolute;width:56px;height:48px;display:flex;align-items:center;justify-content:center;border:1.5px solid #426e6d;border-radius:50%;background:white}.bond-whole{left:14px;top:52px}.bond-part{left:128px;top:22px}.bond-missing{position:absolute;left:128px;top:83px}.bond-missing .answer-space{width:56px;min-width:56px;height:48px;margin:0;border-radius:50%;letter-spacing:0;background:white}
.bond-label{position:absolute;font-size:12px;line-height:1.4;width:56px;text-align:center}.whole-label{left:14px;top:31px}.parts-label{left:128px;top:0}.number-bond-activity>small{display:block;font-size:12px;line-height:1.4;margin-top:12px;white-space:normal}
@media screen and (max-width:1100px){.sheet[data-layout=number-bonds] .questions{grid-template-columns:1fr}}

.sheet[data-layout=ordinal-pictures] .questions{grid-template-columns:minmax(0,1fr);gap:20px}
.ordinal-activity{width:100%;min-width:0}.ordinal-prompt{font-size:20px;line-height:1.4;margin:0 0 10px;white-space:normal}
.ordinal-direction{font-size:13px;line-height:1.4;margin-bottom:5px}.ordinal-direction span{font-size:20px;margin-left:8px}
.ordinal-scroll{max-width:100%;overflow-x:auto;padding:3px 0 8px}.ordinal-scroll:focus-visible{outline:2px solid #176e61;outline-offset:2px}
.ordinal-row{display:flex;flex-wrap:nowrap;gap:12px;width:max-content}.ordinal-row .mark-object{width:56px;height:56px}.ordinal-row .object-icon{width:40px;height:40px}
.ordinal-key{font-size:13px;line-height:1.4;margin:8px 0 0}.ordinal-scroll-help{display:none}
@media screen and (max-width:600px){.sheet[data-layout=ordinal-pictures] .sheet-brand-row{flex-wrap:wrap}.ordinal-scroll-help{display:block;font-size:12px;line-height:1.4;margin-top:4px}.ordinal-row{gap:8px}.ordinal-row .mark-object{width:44px;height:44px}.ordinal-row .object-icon{width:32px;height:32px}}
@media print{.ordinal-scroll{overflow:visible}.ordinal-scroll-help{display:none}}

.early-activity-question .count-zero-space{border:1.5px solid #426e6d;border-radius:6px;min-height:88px;width:100%;max-width:240px;background:white}

.lesson-number-cards{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:6px;max-width:250px;margin:14px 0}
.lesson-number-cards>span{display:flex;align-items:center;justify-content:center;min-width:0;height:48px;border:1px solid #426e6d;border-radius:6px;background:white;color:#183b40;font-size:23px}
.lesson-number-cards>.corrected-card{color:#c01823;font-weight:bold}
.repair-explanation{margin:16px 0}.repair-explanation>summary{cursor:pointer;font-weight:bold;color:#166d5e;padding:8px 0;line-height:1.4}.repair-explanation[open]>summary{margin-bottom:8px}

/* Decimal products: one shared frame, with room for partial products. */
.sheet[data-layout=decimal-products] .questions{grid-template-columns:repeat(2,minmax(0,1fr))}
.decimal-product{width:100%;min-width:0}.decimal-product .equation{white-space:nowrap}.decimal-product .answer-space{width:128px;margin-top:6px}.product-working-space{height:78px;border-bottom:1px dotted #96aaa9}
.decimal-area-model{display:grid;grid-template-columns:repeat(10,16px);width:max-content;border:1px solid #426e6d;margin:16px 0}.decimal-area-model span{width:16px;height:16px;border:1px solid #426e6d;background:white}.decimal-area-model .shaded{background:#176e5c}
@media screen and (max-width:950px){.sheet[data-layout=decimal-products] .questions{grid-template-columns:1fr}.sheet[data-layout=decimal-products] .question{min-height:175px}}

.decimal-division-model{display:flex;flex-wrap:wrap;gap:12px;margin:16px 0}.division-tenths-group{display:flex;border:2px solid #176e5c;border-radius:5px;padding:4px;gap:2px;background:white}.division-tenths-group>span{display:flex;align-items:center;justify-content:center;width:42px;height:42px;background:#e1f0e9;color:#183b40;border:1px solid #426e6d}

.sheet[data-layout=fraction-products] .questions{grid-template-columns:repeat(2,minmax(0,1fr))}.fraction-product{width:100%;min-width:0}.fraction-product .equation{display:flex;align-items:center;gap:12px}.fraction-product .fraction-answer{width:128px;margin-top:6px}.fraction-product .product-working-space{height:70px}
.fraction-groups-model{display:grid;gap:10px;margin:16px 0;max-width:240px}.fourths-strip{display:grid;grid-template-columns:repeat(4,1fr);border:1px solid #426e6d}.fourths-strip>span{height:30px;border:1px solid #426e6d;background:white}.fourths-strip>.filled{background:#176e5c}
@media screen and (max-width:950px){.sheet[data-layout=fraction-products] .questions{grid-template-columns:1fr}.sheet[data-layout=fraction-products] .question{min-height:225px}}

/* Keep fraction story writing areas readable on narrow screens; print stays two-column. */
@media screen and (max-width:1100px){.sheet[data-layout=stories][data-number-domain=fraction] .questions{grid-template-columns:1fr}}
@media screen and (max-width:600px){.story-response.two-fraction-response{grid-template-columns:minmax(0,1fr)}.two-fraction-response>span:nth-child(1){grid-row:1}.two-fraction-response>span:nth-child(3){grid-row:2}.two-fraction-response>span:nth-child(2){grid-row:3}.two-fraction-response>span:nth-child(4){grid-row:4}.sheet .two-fraction-response>.fraction-story-answer{max-width:128px}}

/* Long division equations need the full screen column on tablets. */
@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.division-equation) .questions{grid-template-columns:1fr}}

.extended-product-work .calculation-space{min-height:124px}
@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.extended-product-work) .questions{grid-template-columns:1fr}}

@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.four-addend-response) .questions{grid-template-columns:1fr}}

.tens-boxes{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}.tens-box{padding:12px 4px;border:1px solid #86aaa3;border-radius:8px;background:white;text-align:center}.ten-rods{display:flex;justify-content:center;gap:8px;margin:12px 0}.ten-rod{display:grid;grid-template-rows:repeat(10,8px);width:18px;border:1px solid #176e5c;background:#d8eee4}.ten-rod i{display:block;border-bottom:1px solid #176e5c}.ten-rod i:last-child{border-bottom:0}.tens-box>span{font-size:14px}
@media(max-width:600px){.tens-boxes{grid-template-columns:repeat(2,minmax(0,1fr))}}

.tens-change-model .tens-boxes{grid-template-columns:repeat(2,minmax(0,1fr))}.removed-rod{position:relative}.removed-rod:before,.removed-rod:after{content:'';position:absolute;left:50%;top:0;width:2px;height:100%;background:#c01823;transform:translateX(-50%) rotate(12deg)}.removed-rod:before{transform:translateX(-50%) rotate(-12deg)}
@media(max-width:600px){.tens-change-model .tens-boxes{grid-template-columns:1fr}}

@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.grouped-story-response) .questions,.sheet[data-layout=stories]:has(.multiplier-place-model) .questions{grid-template-columns:1fr}}
.counter-row{display:flex;flex-wrap:wrap;gap:5px;justify-content:center;margin:12px 0 4px;padding:0 6px}.counter-row i{display:block;width:14px;height:14px;border-radius:50%;border:1px solid #214c50}.red-counters i{background:#c01823}.blue-counters i{background:#286da8}

.factor-list-response{font-size:13px}.sheet .factor-list-box{width:100%;height:76px;min-height:76px;margin:6px 0 10px;padding:8px}.factor-list-box .answer{white-space:normal}.factor-list-working .calculation-space{min-height:120px}.factor-array-model .tens-boxes{grid-template-columns:1fr}.factor-array{display:grid;grid-template-columns:repeat(var(--array-columns),minmax(0,14px));gap:5px;justify-content:center;margin:14px 0}.factor-array i{display:block;width:100%;aspect-ratio:1;border-radius:50%;background:#176e5c}
@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.factor-list-response) .questions{grid-template-columns:1fr}}

/* Read the value of every piece before exchanging hundreds or tens. */
.exchange-columns{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.exchange-column{background:white;border:1px solid #86aaa3;border-radius:8px;padding:12px;text-align:center}.exchange-pieces{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;margin:12px 0}.exchange-pieces span{display:flex;align-items:center;justify-content:center;color:#183b40;border:1px solid #426e6d;font-size:13px;font-weight:700}.hundred-piece{width:38px;height:38px;background:#d8eee4}.ten-piece{width:22px;height:48px;background:#e5edf6}.one-piece{width:22px;height:22px;border-radius:50%;background:#fff1d2}@media(max-width:600px){.exchange-columns{grid-template-columns:1fr}}

/* Two long-division stories leave a full column for the written algorithm. */
.question:has(.extended-division-work) .story-question{height:100%;display:flex;flex-direction:column}.extended-division-work{display:flex;flex-direction:column;flex:1;min-height:320px}.extended-division-work .calculation-space{flex:1;min-height:300px}

@media screen and (max-width:1100px){.sheet[data-layout=stories][data-number-domain=decimal] .questions{grid-template-columns:1fr}}

.place-value-table-scroll{max-width:100%;overflow-x:auto}.place-value-table-scroll:focus-visible{outline:3px solid #996000;outline-offset:3px}.place-value-table-scroll .area-products{min-width:480px}

.gcf-story-response,.lcm-story-response{display:flex;flex-wrap:wrap;align-items:center;gap:10px;font-size:13px}.gcf-story-response .answer-space,.lcm-story-response .answer-space{width:95px;margin:6px 0}.gcf-bag-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.gcf-bag{border:1px solid #426e6d;border-radius:10px;padding:12px;background:white;text-align:center}.gcf-bag strong{font-size:14px}.gcf-bag p{font-size:13px;margin:6px 0}.gcf-bag .counter-row{padding:0;margin:8px 0}@media(max-width:600px){.gcf-bag-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}

.two-step-response{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:5px 10px;font-size:13px}.sheet .two-step-response .answer-space{width:100%;min-width:0;margin:0;height:44px}.two-step-final{display:flex;align-items:center;gap:12px;font-size:13px;margin-top:8px}.two-step-final .answer-space{width:95px;margin:0}
@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.two-step-response) .questions,.sheet[data-layout=stories]:has(.vehicle-response) .questions{grid-template-columns:1fr}}

/* Original kindergarten apple art, used only in the teaching examples. */
.k-story-source-model{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:1rem}
.k-story-source-model .object-art{max-width:100%;width:145px}
.k-story-source-model svg{display:block;width:100%;height:auto}
.k-story-source-model .math-sign{font-size:1.5rem;font-weight:700}

.mixed-number{display:inline-flex;align-items:center;gap:4px;white-space:nowrap}

.mixed-number-text{white-space:nowrap}

@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.equal-group-response) .questions{grid-template-columns:1fr}}

.difference-counters{display:block;width:100%;max-width:360px;margin:4px 0 14px}.difference-working .calculation-space{min-height:60px}

.needed-amount-counters{display:block;width:100%;max-width:360px;margin:4px 0 14px}.needed-amount-working .calculation-space{min-height:60px}

.difference-bars{display:block;width:100%;max-width:340px;margin:4px 0 14px}

.whole-scaling-bars{display:block;width:100%;max-width:340px;margin:4px 0 14px}

.whole-scaling-working .calculation-space{min-height:40px}

.story-response.whole-scaling-response>.answer-space{min-width:0}

.multiplier-place-model{display:block;width:100%;max-width:340px;margin:2px 0 5px}.multiplier-place-working .calculation-space{min-height:55px}.multiplier-scaling-example{margin:16px 0;padding:12px}.multiplier-scaling-example svg{display:block;width:100%;max-width:560px;height:auto}

.identity-group-picture{display:block;width:100%;max-width:320px;margin:4px 0 14px}.identity-group-working .calculation-space{min-height:50px}.story-response.identity-group-response>.answer-space{min-width:0}

.larger-missing-bar{display:block;width:100%;max-width:340px;margin:4px 0 14px}.larger-missing-working .calculation-space{min-height:55px}.story-response.larger-missing-response>.answer-space{min-width:0}

.story-response.thousand-difference-response>.answer-space{min-width:0}

.larger-sharing-bars{display:block;width:100%;max-width:340px;margin:4px 0 14px}.story-response.larger-sharing-response>.answer-space{min-width:0}
.larger-sharing-working .calculation-space{min-height:55px}

.two-digit-group-bars{display:block;width:100%;max-width:340px;margin:4px 0 14px}.story-response.two-digit-group-response>.answer-space{min-width:0}.two-digit-group-working .calculation-space{min-height:55px}

.small-grouping-model{margin:16px 0}
.smaller-remainder-example{margin:16px 0}

@media screen and (max-width:1100px){.sheet[data-layout=stories]:has(.two-digit-sharing-model) .questions{grid-template-columns:1fr}}

.two-digit-sharing-model{display:block;width:100%;max-width:340px;margin:2px 0 5px}.exact-sharing-working .calculation-space{min-height:55px}.story-response.exact-sharing-response>.answer-space{min-width:0}.exact-sharing-example{margin:16px 0;padding:10px}.exact-sharing-example svg{display:block;width:100%;max-width:340px;height:auto}

/* Shared country switch in the site header. */
.top-nav .locale-switch{display:inline-flex;align-items:center;gap:7px;min-height:44px;white-space:nowrap}.locale-icon{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;border:1px solid currentColor;border-radius:50%;font-size:11px;font-weight:700;letter-spacing:.03em}.locale-switch:focus-visible{outline:2px solid currentColor;outline-offset:3px}

/* Keep the brand visible while browsing long menus or lessons. */
@media screen {
 html{scroll-padding-top:var(--site-header-offset,140px)}
 .site-header{position:sticky;top:0;z-index:20;background:#f5f8f5;box-shadow:0 1px 0 #c9ddd6}
 .skip:focus{position:fixed;z-index:30}
 @media(min-width:761px){.browse{top:var(--site-header-offset,140px);max-height:calc(100dvh - var(--site-header-offset,140px) - 16px);overflow-y:auto;overscroll-behavior:contain}}
}

/* Fixed application frame: lists scroll independently beneath the brand. */
@media screen {
 body{height:100vh;height:100dvh;overflow:hidden;display:flex;flex-direction:column}
 .notice,.site-header,body>footer{flex-shrink:0}
 .site-header{position:relative;top:auto;width:100%;z-index:20}
 .layout{flex:1;width:100%;min-height:0;margin:0 auto;padding-top:16px;padding-bottom:16px;grid-template-rows:minmax(0,1fr);overflow:hidden}
 .layout>main{min-height:0;overflow-y:auto;overscroll-behavior:contain;scrollbar-gutter:stable;padding:4px 12px 24px 4px;scroll-padding-top:16px}
 .layout>aside{min-height:0;overflow-y:auto;overscroll-behavior:contain;scrollbar-gutter:stable}
 .layout .browse{position:static;max-height:none;overflow:visible}
 body>footer{width:100%;padding:10px 24px;max-height:15dvh;overflow:auto}
 @media(max-width:760px){.layout{grid-template-rows:auto minmax(0,1fr);gap:12px}.layout>aside{max-height:28dvh}.layout>main{padding-right:4px}.site-header{padding:10px 16px;gap:10px}.notice{padding:4px 12px}}
}

@media screen{html{height:100%;overflow:clip}body{position:fixed;inset:0;width:100%}.layout{overflow:clip}}