/* Fit the reference layout on shorter laptop screens without changing the desktop composition. */
@media (min-width: 851px) and (max-height: 950px) {
  body { zoom: .68; }
}

@media (min-width: 851px) and (max-height: 760px) {
  body { zoom: .58; }
}

.problem-entry {
  margin-top: 34px;
  padding: 23px 24px;
  background: #fff;
  border: 1px solid #e4eeee;
  border-radius: 18px;
  box-shadow: 0 4px 18px #17252208;
}

.problem-entry h3 {
  margin: 0;
  color: #30363b;
  font: 700 18px "DM Sans", sans-serif;
}

.problem-entry > p {
  margin: 7px 0 17px;
  color: #858d94;
  font-size: 14px;
}

.problem-controls {
  display: flex;
  gap: 10px;
  align-items: center;
}

.problem-controls > input {
  min-width: 0;
  flex: 1;
  height: 48px;
  padding: 0 16px;
  border: 1px solid #dce5e5;
  border-radius: 10px;
  color: #32393e;
  font: 15px "DM Sans", sans-serif;
}

.problem-controls > input:focus {
  outline: 2px solid #16bfae44;
  border-color: #16bfae;
}

.upload-button,
.problem-controls > button {
  height: 48px;
  border-radius: 10px;
  padding: 0 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: 700 14px "DM Sans", sans-serif;
  cursor: pointer;
}

.upload-button {
  border: 1px solid #b9dfda;
  color: #178f83;
  background: #f2fbf9;
}

.upload-button input { display: none; }

.problem-controls > button {
  border: 0;
  color: #fff;
  background: #16bfae;
}

.problem-controls > button:disabled {
  color: #a1aaa9;
  background: #e9eeee;
  cursor: not-allowed;
}

.problem-controls > button span { margin-left: 9px; font-size: 18px; }
.problem-file-name,.problem-status { min-height: 17px; }
.problem-file-name { color: #198d81 !important; }
.problem-status { color: #5b656b !important; }

.subject-empty-state {
  margin-top: 26px;
  min-height: 270px;
  padding: 54px 28px;
  display: grid;
  justify-items: center;
  align-content: center;
  text-align: center;
  background: #fff;
  border: 1px dashed #cbdedb;
  border-radius: 20px;
}

.subject-empty-state[hidden] { display: none; }
.empty-state-icon { color: #16bfae; font-size: 27px; }
.subject-empty-state h3 { margin: 14px 0 8px; color: #30363b; font: 700 22px "DM Sans", sans-serif; }
.subject-empty-state p { max-width: 470px; margin: 0; color: #7f898f; line-height: 1.55; }
.subject-empty-state .empty-state-actions { display: none; }
.resource-search-empty { margin: 18px 0; padding: 24px; border: 1px dashed #d5e2df; border-radius: 13px; color: #7f898f; background: #fbfdfd; text-align: center; }
.resource-search-empty[hidden] { display: none; }
.detail-empty-state { margin-top: 22px; padding: 28px 24px; border: 1px dashed #d5e2df; border-radius: 14px; background: #fbfdfd; text-align: center; }
.detail-empty-state h3 { margin: 0; color: #59666b; font: 700 18px "DM Sans", sans-serif; }
.sidebar-empty-copy { margin: 12px 0 0; color: #89969a; font-size: 13px; line-height: 1.5; }
.empty-state-actions { display: flex; gap: 12px; margin-top: 24px; }
.empty-state-actions button { border: 0; border-radius: 10px; padding: 11px 16px; font: 700 14px "DM Sans", sans-serif; cursor: pointer; }
#explore-math { color: #fff; background: #16bfae; }
.empty-state-actions .text-button { color: #168f83; background: #edf9f7; }

.knowledge-detail { margin-top: 28px; }
.knowledge-detail[hidden] { display: none; }
.detail-breadcrumb { margin-bottom: 28px; color: #9ca4aa; font-size: 14px; }
.detail-breadcrumb span { margin: 0 8px; color: #d1d6d9; }
.detail-breadcrumb button { padding: 0; border: 0; background: transparent; color: inherit; font: inherit; cursor: pointer; }
.detail-breadcrumb button:hover { color: #178f83; text-decoration: underline; }
.knowledge-layout { display: grid; grid-template-columns: minmax(0, 1fr) 295px; gap: 42px; align-items: start; }
.knowledge-article { max-width: 780px; }
.detail-entry-copy { margin: 0 0 18px; color: #159c8e; font: 700 15px "DM Sans", sans-serif; }
.knowledge-entry-copy { max-width: 780px; padding: 17px 20px; border: 1px solid #dcefeb; border-radius: 14px; background: #f3fbf9; color: #2f7770; font-size: 21px; line-height: 1.4; }
.knowledge-article h2 { margin: 0; color: #252a2f; font: 800 43px/1.1 "Nunito", sans-serif; letter-spacing: -1.2px; }
.detail-lead { margin: 18px 0 34px; color: #596269; font-size: 18px; line-height: 1.55; }
.knowledge-html-body { color: #334047; }
.knowledge-html-body .knowledge-featured-answer { margin: 10px 0 34px; padding: 22px 24px; border: 2px solid #9ce4b6; border-radius: 14px; background: linear-gradient(135deg,#f0fdf4,#ecfdf5); }
.knowledge-answer-badge { display: inline-flex; margin-bottom: 10px; padding: 4px 10px; border-radius: 6px; color: #fff; background: #10b981; font-size: 12px; font-weight: 800; }
.knowledge-answer-lead { margin: 0 0 8px !important; color: #065f46 !important; font-size: 19px !important; font-weight: 800; }
.knowledge-html-body .knowledge-featured-answer p:last-child { margin: 0; color: #166534; line-height: 1.6; }
.knowledge-section { margin-top: 34px; }
.knowledge-section > h3 { display: flex; align-items: center; gap: 10px; padding-bottom: 9px; border-bottom: 1px solid #e2e8ef; }
.knowledge-section-number { color: #168f83; }
.knowledge-section h4 { margin: 8px 0; color: #1e293b; font-size: 15px; line-height: 1.35; }
.knowledge-section > p { margin-bottom: 14px; }
.knowledge-misconceptions { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 12px; margin: 18px 0; }
.knowledge-misconceptions article { padding: 16px; border: 1px solid #dfe7ea; border-radius: 12px; background: #f8fafc; }
.knowledge-misconceptions article > span { display: block; margin-bottom: 7px; color: #ef4444; font-size: 11px; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; }
.knowledge-misconceptions article p { margin: 0; color: #64748b; font-size: 14px; line-height: 1.5; }
.knowledge-proof-box { margin: 18px 0; padding: 18px 20px; border-left: 4px solid #2563eb; border-radius: 0 10px 10px 0; background: #f8fafc; }
.knowledge-equation { margin-bottom: 12px; color: #1e3a8a; font-size: 19px; font-weight: 700; }
.knowledge-proof-box ul { margin: 8px 0 0; padding-left: 21px; }
.knowledge-proof-box li { margin: 7px 0; color: #334155; font-size: 14px; line-height: 1.55; }
.knowledge-table-wrap { margin: 18px 0; overflow-x: auto; border: 1px solid #e2e8f0; border-radius: 9px; }
.knowledge-table-wrap table { width: 100%; min-width: 560px; border-collapse: collapse; text-align: left; font-size: 13px; }
.knowledge-table-wrap th,.knowledge-table-wrap td { padding: 12px 14px; border-bottom: 1px solid #e2e8f0; }
.knowledge-table-wrap th { color: #475569; background: #f8fafc; font-size: 11px; letter-spacing: .04em; text-transform: uppercase; }
.knowledge-table-wrap tr:last-child td { border-bottom: 0; }
.knowledge-badge { display: inline-block; padding: 3px 8px; border-radius: 5px; font-size: 11px; font-weight: 800; white-space: nowrap; }
.knowledge-badge.yes { color: #047857; background: #ecfdf5; }.knowledge-badge.no { color: #b91c1c; background: #fef2f2; }
.knowledge-hierarchy-diagram { margin: 18px 0; padding: 18px; border-radius: 13px; background: #f1f5f9; }
.knowledge-hierarchy-diagram > div { padding: 14px; border: 2px dashed #64748b; border-radius: 10px; background: rgba(255,255,255,.75); }
.knowledge-hierarchy-diagram > div > div { padding: 12px; border: 2px solid #3b82f6; border-radius: 9px; background: #dbeafe; }
.knowledge-hierarchy-diagram > div > div > div { padding: 11px; border: 2px solid #8b5cf6; border-radius: 8px; background: #ede9fe; }
.knowledge-hierarchy-diagram .whole-set { padding: 10px; border: 2px solid #f59e0b; border-radius: 8px; background: #fef3c7; }
.knowledge-hierarchy-diagram b { display: block; color: #334155; font-size: 13px; }
.knowledge-hierarchy-diagram .whole-set > span { display: inline-block; margin: 6px 0; padding: 2px 8px; border-radius: 999px; color: #fff; background: #f59e0b; font-size: 11px; font-weight: 800; }
.knowledge-hierarchy-diagram .whole-set > div { padding: 8px; border: 1px solid #cbd5e1; border-radius: 7px; background: #fff; }
.knowledge-hierarchy-diagram small { color: #64748b; font-size: 12px; }
.knowledge-answer-content { margin-top: 11px; padding-top: 12px; border-top: 1px dashed #d8e1e4; color: #334155; font-size: 14px; line-height: 1.55; }
.knowledge-section details { margin-bottom: 10px; padding: 13px 16px; border: 1px solid #dfe7ea; border-radius: 9px; background: #f8fafc; }
.knowledge-section details[open] { background: #fff; border-color: #b9d5d0; box-shadow: 0 2px 8px rgba(30,41,59,.05); }
.knowledge-section summary { color: #1e293b; font-size: 14px; font-weight: 700; cursor: pointer; }
.knowledge-next-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 12px; }
.knowledge-next-card { display: block; min-height: 100px; padding: 15px; border: 1px solid #dfe7ea; border-radius: 10px; color: inherit; background: #fff; text-decoration: none; }
.knowledge-next-card:hover { border-color: #168f83; box-shadow: 0 2px 8px rgba(22,143,131,.1); }
.knowledge-next-card span { display: block; margin-bottom: 6px; color: #168f83; font-size: 11px; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; }
.knowledge-next-card b { color: #263137; font-size: 14px; line-height: 1.4; }
.article-section { margin-top: 31px; }
.article-section h3,.citations h3,.related-card h3 { margin: 0 0 12px; color: #2d3338; font: 800 25px/1.2 "Nunito", sans-serif; letter-spacing: -.35px; }
.article-section p { margin: 0; color: #4d575e; font-size: 16px; line-height: 1.68; }
.concept-grid { display: grid; gap: 10px; grid-template-columns: repeat(3,minmax(0,1fr)); }
.concept-grid div { min-height: 108px; padding: 16px; border-radius: 12px; background: #f3fbfa; }
.concept-grid b,.concept-grid span { display: block; }
.concept-grid b { margin-bottom: 7px; color: #168f83; font-size: 13px; }
.concept-grid span { color: #58636a; font-size: 14px; line-height: 1.4; }
.example-section { padding: 21px; border-radius: 15px; background: #f8f8f6; }
.conclusion-section { padding-top: 22px; border-top: 1px solid #e5e9e8; }
.citations { margin-top: 34px; padding-top: 22px; border-top: 1px solid #e5e9e8; }
.citations h3 { font-size: 18px; }
.citations a { display: block; color: #178f83; text-decoration: none; }
.citations a:hover { text-decoration: underline; }
.citations a b,.citations a span { display: block; }
.citations a span { margin-top: 4px; color: #899298; font-size: 13px; }
.related-card { padding: 25px; border-radius: 18px; background: #f8faf9; }
.typical-error-entry { margin: -25px -25px 22px; padding: 20px 25px; border-bottom: 1px solid #e2e8e6; background: #eefaf8; }
.typical-error-entry[hidden] { display: none; }
.typical-error-entry h3 { margin: 0 0 7px; color: #168f83; font-size: 18px; }
.typical-error-entry p { margin: 0 0 13px; color: #68777b; font-size: 13px; line-height: 1.45; }
.typical-error-open { border: 0; padding: 0; color: #168f83; background: transparent; font: 700 13px "DM Sans", sans-serif; cursor: pointer; }
.typical-error-open span { margin-left: 5px; font-size: 16px; }
.typical-error-inline { margin: 18px 0 0; padding: 13px 0; border-top: 1px solid #e5e9e8; }
.typical-error-inline[hidden] { display: none; }
.typical-error-inline .typical-error-open { padding: 0; }
#typical-error-inline { margin: 20px 0 0; padding: 16px 19px; border: 1px solid #9eddd4; border-radius: 13px; border-bottom-width: 1px; background: linear-gradient(100deg,#effbf9,#f8fdfc); box-shadow: 0 5px 16px rgba(22,143,131,.08); }
#typical-error-inline:hover { border-color: #16bfae; background: #e9faf7; box-shadow: 0 7px 20px rgba(22,143,131,.14); }
#typical-error-inline .typical-error-entry-list { display: grid; gap: 8px; margin-top: 10px; }
#typical-error-inline .typical-error-open { display: flex; align-items: center; justify-content: space-between; gap: 12px; width: 100%; padding: 11px 12px; border: 1px solid #cfe9e5; border-radius: 10px; color: #344047; background: #fff; text-align: left; font: 600 13px/1.45 "DM Sans", sans-serif; }
#typical-error-inline .typical-error-open:hover { border-color: #16bfae; color: #087d70; }
#typical-error-inline .typical-error-open span { flex: 1; }
#typical-error-inline .typical-error-open b { color: #16a594; font-size: 17px; }
.related-card h3 { margin-bottom: 15px; font-size: 23px; }
.related-question { width: 100%; padding: 17px 0; border: 0; border-bottom: 1px solid #e2e8e6; background: transparent; color: #3e474e; text-align: left; cursor: pointer; }
.related-question:last-child { border-bottom: 0; }
.related-question span,.related-question small { display: block; }
.related-question span { font: 600 15px/1.4 "DM Sans", sans-serif; }
.related-question small { margin-top: 5px; color: #1b9b8d; font-size: 12px; }
.previous-next { display: flex; justify-content: space-between; max-width: 780px; margin-top: 42px; padding-top: 20px; border-top: 1px solid #e5e9e8; }
.previous-next button { border: 0; background: transparent; color: #178f83; font: 700 14px "DM Sans", sans-serif; cursor: pointer; }
.previous-next button:disabled { color: #b9c0c3; cursor: not-allowed; }

.question-detail { margin-top: 28px; }
.question-detail[hidden],.solution-content[hidden] { display: none; }
.typical-error-detail[hidden] { display: none; }
.question-detail .question-type,
.question-detail .question-article > h2,
.question-detail .question-meta,
.question-detail .demo-access,
.question-detail .solution-summary { display: none; }
.question-layout { display: grid; grid-template-columns: minmax(0, 1fr) 295px; gap: 42px; align-items: start; }
.question-layout > .related-card { position: sticky; top: 24px; }
.question-article { max-width: 780px; }
.question-type { margin: 0 0 11px; color: #168f83; font-size: 12px; font-weight: 700; letter-spacing: 1.25px; }
.question-article h2 { margin: 0; color: #252a2f; font: 800 40px/1.13 "Nunito", sans-serif; letter-spacing: -1px; }
.question-meta { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0 28px; }
.question-meta span { padding: 5px 9px; border-radius: 999px; background: #f0f5f4; color: #6f7b80; font-size: 12px; }
.question-prompt { padding: 22px; border-radius: 15px; background: #f8faf9; border: 1px solid #e3ecea; }
.question-prompt h3 { margin: 0 0 9px; color: #778188; font-size: 13px; letter-spacing: .7px; text-transform: uppercase; }
.question-prompt p { margin: 0; color: #2e363b; font-size: 21px; }
.question-image-figure { display: flex; justify-content: center; margin: 0 0 18px; padding: 12px; border-radius: 12px; background: #fff; }
.question-image-figure[hidden] { display: none; }
.question-image-figure img { display: block; width: 100%; max-height: 300px; object-fit: contain; border-radius: 8px; }
.solution-summary { margin: 18px 0; color: #657077; line-height: 1.55; }
.solution-overlay { position: relative; overflow: hidden; margin-top: 24px; padding: 21px; border: 1px solid #cfe5e1; border-radius: 18px; background: #f4fbfa; }
.solution-gate { margin-top: 24px; }
.solution-gate > .solution-overlay { margin-top: 0; }
.solution-overlay[hidden] { display: none; }
.solution-mask { display: grid; gap: 9px; min-height: 100px; padding: 18px; border-radius: 12px; background: linear-gradient(135deg,#d9e7e5,#f1f8f6); color: #7e9692; font-size: 12px; opacity: .72; }
.solution-mask span { color: #5e817a; font: 800 14px "Nunito", sans-serif; }.solution-mask i { display: block; width: 82%; height: 8px; border-radius: 99px; background: #fff9; }.solution-mask i:nth-child(3) { width: 65%; }.solution-mask i:nth-child(4) { width: 74%; }
.solution-overlay-copy { display: grid; gap: 5px; margin: 17px 0 14px; }.solution-overlay-copy strong { color: #2c5550; font: 800 19px "Nunito", sans-serif; }.solution-overlay-copy span { color: #70817f; font-size: 13px; line-height: 1.45; }
.view-solution { margin-top: 17px; padding: 13px 17px; border: 0; border-radius: 10px; background: #16bfae; color: #fff; font: 700 15px "DM Sans", sans-serif; cursor: pointer; }
.view-solution span { margin-left: 9px; font-size: 18px; }
.view-solution:disabled { cursor: wait; opacity: .72; }
.demo-access { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin: -12px 0 20px; color: #778188; font-size: 12px; }
.demo-access label { font-weight: 700; }
.demo-access select { padding: 5px 24px 5px 8px; border: 1px solid #d7e3e1; border-radius: 7px; color: #46535a; background: #fff; font: 12px "DM Sans", sans-serif; }
.demo-access span { padding-left: 3px; color: #198d81; font-weight: 700; }
.solution-limit { margin-top: 26px; padding: 25px; border: 1px solid #f0d79e; border-radius: 16px; background: #fff8e8; }
.solution-limit[hidden] { display: none; }
.solution-limit h3 { margin: 0; color: #564521; font: 800 23px/1.25 "Nunito", sans-serif; }
.solution-limit p { margin: 9px 0 18px; color: #76633b; line-height: 1.5; }
.solution-limit button { border: 0; border-radius: 10px; padding: 12px 15px; color: #573b00; background: #ffc553; font: 700 14px "DM Sans", sans-serif; cursor: pointer; }
.solution-limit button span { margin-left: 8px; font-size: 18px; }
.solution-content { margin-top: 28px; }
.guided-explanation { display: grid; gap: 24px; }
.guided-explanation[hidden] { display: none; }
.guided-explanation h3 { margin: 0 0 10px; color: #2d3338; font: 800 24px/1.2 "Nunito", sans-serif; }
.guided-explanation h4 { margin: 0 0 9px; color: #168f83; font: 800 18px/1.3 "Nunito", sans-serif; }
.guided-explanation p { margin: 8px 0; color: #4d575e; font-size: 15px; line-height: 1.65; }
.guided-explanation .guided-part { padding: 22px; border-radius: 15px; background: #fff; border: 1px solid #e3ecea; }
.guided-figure { margin: 0 0 18px; padding: 12px; border-radius: 12px; background: #f8faf9; text-align: center; }
.guided-figure img { display: block; width: 100%; max-height: 380px; object-fit: contain; border-radius: 8px; }
.guided-figure figcaption { margin-top: 8px; color: #778188; font-size: 12px; }
.guided-explanation .guided-question { margin: 14px 0; padding: 13px 15px; border-radius: 10px; background: #f4fbfa; color: #2f5550; font-weight: 700; }
.guided-explanation .guided-equation { padding: 13px 15px; border-radius: 10px; background: #f6f8fb; color: #263844; font-family: Georgia, serif; line-height: 1.7; }
.guided-explanation details { margin: 12px 0; padding: 12px 14px; border-radius: 10px; background: #fff8e8; color: #66532a; }
.guided-explanation summary { cursor: pointer; font-weight: 700; }
.guided-explanation .guided-answer { padding: 22px; border-radius: 15px; background: #effbf4; border: 1px solid #d5eee0; }
.guided-explanation .guided-answer h3 { color: #16a765; }
.guided-question-page .solution-product-section { display: none; }
.solution-product-section { padding-top: 24px; border-top: 1px solid #e5e9e8; }
.solution-product-section h3 { margin-bottom: 12px; }
.solution-product-section h4 { margin: 15px 0 5px; color: #198d81; font-size: 13px; }
.what-you-got-right { padding: 21px; border-top: 0; border-radius: 15px; background: #effbf4; }
.what-you-got-right h3 { color: #16a765; text-transform: uppercase; }
.review-steps { display: grid; gap: 9px; margin: 0; padding: 0; list-style: none; }
.review-steps li { display: grid; grid-template-columns: 25px minmax(0,1fr) auto; gap: 9px; align-items: center; padding: 11px 12px; border: 1px solid #dcece8; border-radius: 10px; background: #f8fcfb; color: #4d575e; font-size: 14px; }
.review-steps li > b { display: grid; place-items: center; width: 22px; height: 22px; border-radius: 50%; color: #168f83; background: #e5f7f3; font-size: 12px; }
.review-steps li > strong { color: #168f83; font-size: 12px; }
.diagnosis-section { padding: 21px; border-radius: 15px; background: #fff8f4; border-top: 0; }
.diagnosis-section h3 { color: #ef4b39; text-transform: uppercase; }
.checkpoint-list { display: grid; gap: 8px; }
.checkpoint-list p { padding: 10px 12px; border-radius: 9px; background: #f3fbfa; }
.checkpoint-list b { color: #168f83; }
.collapsible-demo h3 { margin: 0; padding: 13px 0; border-bottom: 1px solid #e5e9e8; font-size: 18px; }
.collapsible-demo p { padding: 12px 0 3px; }
.practice-section { padding: 21px; border-top: 0; border-radius: 15px; background: #eefaf8; }
.practice-card { width: 100%; margin-top: 8px; padding: 19px; border: 0; border-radius: 12px; color: #fff; background: linear-gradient(135deg,#1779b6,#16bfae); font: 700 15px "DM Sans", sans-serif; text-align: left; cursor: pointer; }
.practice-actions { display: flex; gap: 9px; margin-top: 11px; }.practice-actions button { flex: 1; padding: 9px; border: 1px solid #9cddd3; border-radius: 999px; color: #168f83; background: #fff; font: 700 12px "DM Sans", sans-serif; cursor: pointer; }
.similar-question-rail { margin-top: 18px; padding-top: 17px; border-top: 1px solid #e2e8e6; }
.similar-question-rail h4 { margin: 0; color: #168f83; font-size: 12px; letter-spacing: .75px; text-transform: uppercase; }
.similar-question-rail .related-question { margin-top: 4px; padding: 13px 0 2px; }
.rate-answer { margin-top: 31px; padding: 21px; border-radius: 15px; background: #f4fbfa; border: 1px solid #d5ece7; }
.rate-answer h3 { margin: 0; color: #28353a; font: 800 20px "Nunito", sans-serif; }
.rate-answer p { margin: 7px 0 14px; color: #737f85; font-size: 14px; }
.rate-answer div { display: flex; flex-wrap: wrap; gap: 9px; }
.rate-button { padding: 9px 12px; border: 1px solid #cce4df; border-radius: 9px; background: #fff; color: #4d5b61; font: 600 13px "DM Sans", sans-serif; cursor: pointer; }
.rate-button:hover,.rate-button.selected { border-color: #16bfae; color: #117d72; background: #e8f8f5; }
.rate-status { min-height: 18px; margin-bottom: 0 !important; color: #198d81 !important; }
.typical-error-layout { display: grid; grid-template-columns: minmax(0,1fr) 295px; gap: 42px; align-items: start; }
.typical-error-article { max-width: 780px; }
.typical-error-article h2 { margin: 0; color: #252a2f; font: 800 40px/1.13 "Nunito", sans-serif; letter-spacing: -1px; }
.typical-error-images { display: grid; gap: 16px; margin-top: 24px; }
.typical-error-images figure { margin: 0; padding: 14px; border: 1px solid #e1ebe8; border-radius: 15px; background: #fff; }
.typical-error-images img { display: block; width: 100%; max-height: 360px; object-fit: contain; border-radius: 9px; background: #f7faf9; }
.typical-error-images figcaption { margin-top: 8px; color: #168f83; font-size: 12px; font-weight: 700; }
.typical-error-content { display: grid; gap: 18px; margin-top: 22px; }
.typical-error-content[hidden] { display: none; }
.typical-error-specialized .typical-error-review { display: none; }
.typical-error-block { padding: 22px; border-top: 1px solid #e5e9e8; }
.typical-error-block h3 { margin: 0 0 16px; color: #2d3338; font: 800 23px/1.25 "Nunito", sans-serif; }
.review-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; margin-bottom: 22px; }
.review-heading h3 { margin: 5px 0 0; color: #11181d; font-size: 32px; }
.question-label { color: #11181d; font-size: 18px; font-weight: 800; }
.review-status,.field-status { display: inline-flex; align-items: center; justify-content: center; white-space: nowrap; border: 2px solid currentColor; border-radius: 999px; padding: 5px 14px; font-size: 14px; font-weight: 800; }
.review-status.correct { color: #10a968; background: #effbf4; }.review-status.incorrect { color: #ef4b39; background: #fff4f1; }
.typical-error-block h4 { margin: 19px 0 7px; color: #ef4b39; font-size: 14px; text-transform: uppercase; letter-spacing: .5px; }
.typical-error-block h4.positive-heading { color: #119b62; }
.typical-error-block h4.next-steps-heading { color: #20262b; }
.typical-error-block h4.dark-heading { color: #20262b; }
.typical-error-block h4.field-heading { display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.field-status { color: #ef8a13; background: #fffaf0; border-width: 1.5px; font-size: 13px; padding: 5px 12px; }
.field-status.none { color: #ef8a13; }
.typical-error-block h5 { margin: 14px 0 5px; color: #2d3338; font-size: 15px; }
.typical-error-block p,.typical-error-block li { color: #4d575e; font-size: 15px; line-height: 1.6; }
.typical-error-block ul,.typical-error-block ol { margin: 8px 0 0; padding-left: 22px; }
.error-step { display: grid; grid-template-columns: 28px minmax(0,1fr) auto 28px; gap: 10px; align-items: center; padding: 18px 0; border-bottom: 1px solid #dfe5e5; }
.error-step > b { display: grid; place-items: center; width: 24px; height: 24px; border-radius: 50%; background: #f1f4f4; color: #6f7b80; font-size: 12px; }
.error-step span { color: #303a40; font-size: 15px; }
.error-step strong { display: none; font-size: 12px; }
.error-step.correct strong { color: #16a765; }.error-step.incorrect strong { color: #ef4b39; }.error-step.warning strong { color: #d98917; }
.step-status-icon { display: grid; place-items: center; width: 25px; height: 25px; border-radius: 50%; color: #fff; background: #16b36e; font-size: 17px; font-style: normal; font-weight: 900; line-height: 1; }
.error-step.incorrect .step-status-icon { background: #ef4b39; }.error-step.warning .step-status-icon { background: #f0a01a; font-size: 15px; }
.error-correction { padding: 12px 14px; border-radius: 9px; background: #effbf4; color: #168f83 !important; }
.path-start,.path-final { display: grid; gap: 6px; margin: 12px 0; padding: 14px 16px; border-radius: 10px; background: #f6f7f7; color: #354047; }
.path-start b,.path-final b { color: #6c777c; font-size: 12px; text-transform: uppercase; letter-spacing: .5px; }.path-final { background: #effbf4; }.path-final b { color: #168f83; }
.lock-in-block h3 { color: #168f83; }
.lock-in-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 18px; margin-top: 15px; }
.flip-card { display: block; width: 100%; min-width: 0; min-height: 260px; padding: 0; border: 0; background: transparent; text-align: left; perspective: 1000px; cursor: pointer; }
.flip-card-inner { position: relative; display: block; width: 100%; height: 100%; min-height: 260px; transition: transform .55s ease; transform-style: preserve-3d; }
.flip-card.is-flipped .flip-card-inner { transform: rotateY(180deg); }
.flip-card-face { position: absolute; inset: 0; display: flex; flex-direction: column; padding: 22px; border: 1px solid #dce9e6; border-radius: 12px; background: #f2f8f7; backface-visibility: hidden; box-shadow: 0 5px 14px rgba(33,61,67,.06); }
.flip-card-face > strong { margin-bottom: 18px; color: #28343a; font-size: 14px; letter-spacing: 1px; }
.flip-card-face p { margin: 0; color: #20262b; line-height: 1.55; }
.flip-card-back { transform: rotateY(180deg); background: #effbf4; }
.flip-card-back strong { color: #119b62; font-size: 13px; text-transform: uppercase; }
.flip-card-hint { margin-top: auto !important; color: #738087 !important; font-size: 12px; }
.practice-set { margin-top: 22px; padding-top: 28px; border-top: 1px solid #dfe7e5; }
.practice-set-heading { display: flex; align-items: center; gap: 10px; color: #20262b; font-size: 18px; }
.practice-number { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; color: #fff; background: #168f83; font-size: 13px; font-weight: 800; }
.practice-set-question { margin: 15px 0 0; color: #303a40; font-size: 16px; line-height: 1.65; }
.practice-answer { margin-top: 14px; padding: 18px 20px; border-left: 4px solid #168f83; background: #f8fcfb; }
.practice-answer h4 { margin: 0 0 10px; color: #28343a; font-size: 14px; }
.practice-answer p { margin: 8px 0 0; color: #3f4b51; line-height: 1.65; }
.practice-answer strong { color: #168f83; }
.practice-steps { margin-top: 15px; padding: 18px 20px; border-radius: 12px; background: #f7f8f8; }
.practice-steps h4 { margin: 0 0 9px; color: #20262b; font-size: 14px; }
.practice-steps p { margin: 8px 0; color: #3f4b51; line-height: 1.65; }
.final-answer-section { border-top: 0; padding-top: 14px; }
.final-answer-section > .practice-set-heading { margin-bottom: 14px; }
.answer-list { display: grid; gap: 10px; margin-top: 0; padding: 0; background: transparent; }
.answer-list p { display: grid; grid-template-columns: 46px minmax(0,1fr); column-gap: 16px; align-items: center; margin: 0; padding: 17px 20px; border: 1px solid #dce4e5; border-radius: 13px; background: #fff; box-shadow: 0 3px 10px rgba(35,57,61,.05); }
.answer-list p > strong { align-self: stretch; display: flex; align-items: center; border-right: 1px solid #dce4e5; color: #16ad8c; font-size: 16px; }
.answer-list p > span { color: #1f292e; line-height: 1.55; }
.answer-list p { color: #1f292e; line-height: 1.55; }
.steps-title { margin-top: 30px; }
.steps-panel { margin-top: 0; padding: 22px; border: 1px solid #dce4e5; border-radius: 14px; background: #fff; }
.steps-panel > p { margin: 10px 0; }
.steps-panel > p strong:first-child { color: #1d282e; }
.steps-panel > p:nth-of-type(1),.steps-panel > p:nth-of-type(5),.steps-panel > p:nth-of-type(10) { position: relative; display: flex; align-items: center; gap: 12px; margin-top: 22px; padding-top: 18px; border-top: 1px solid #e2e8e7; font-size: 16px; }
.steps-panel > p:nth-of-type(1)::before,.steps-panel > p:nth-of-type(5)::before,.steps-panel > p:nth-of-type(10)::before { flex: 0 0 30px; display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; color: #fff; background: #168f83; font-weight: 800; }
.steps-panel > p:nth-of-type(1)::before { content: 'a'; }.steps-panel > p:nth-of-type(5)::before { content: 'b'; }.steps-panel > p:nth-of-type(10)::before { content: 'c'; }
.steps-panel h4 { display: flex; align-items: center; gap: 12px; margin: 0 0 14px; color: #263137; font-size: 16px; }
.steps-panel h4::before { content: ''; display: inline-grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; color: #fff; background: #168f83; }
.steps-panel p { font-size: 15px; }
.steps-panel .common-pitfall { margin: 14px 0; padding: 10px 14px; border-left: 4px solid #dce4e5; background: #fafafa; font-style: italic; }
.typical-error-review { margin-top: 28px; padding: 22px; border-radius: 15px; background: #f4fbfa; border: 1px solid #d5ece7; }
.typical-error-review h3 { margin: 0 0 8px; color: #28353a; font: 800 23px "Nunito", sans-serif; }
.typical-error-review p { margin: 0; color: #657277; line-height: 1.55; }
.typical-error-template { display: grid; gap: 8px; margin-top: 16px; }
.typical-error-template b { padding: 10px 12px; border-radius: 9px; color: #168f83; background: #fff; font-size: 13px; }
.typical-error-related { position: sticky; top: 24px; }
.typical-error-sibling-list { display: grid; gap: 8px; margin-top: 14px; }
.typical-error-sibling { display: grid; gap: 5px; width: 100%; padding: 13px 14px; border: 1px solid #e0e9e7; border-radius: 10px; background: #fff; color: #344047; text-align: left; cursor: pointer; }
.typical-error-sibling:hover,.typical-error-sibling.active { border-color: #16bfae; background: #effbf8; }
.typical-error-sibling span { font-weight: 600; font-size: 13px; line-height: 1.45; }.typical-error-sibling small { color: #789087; font-size: 11px; }
.typical-error-feedback { margin-top: 30px; padding: 20px 0; border-top: 1px solid #e5e9e8; }
.typical-error-feedback h3 { margin: 0 0 10px; color: #28353a; font: 800 18px "Nunito", sans-serif; }
.typical-error-feedback > div { display: flex; gap: 9px; }
.typical-rate-button { padding: 9px 13px; border: 1px solid #cce4df; border-radius: 9px; background: #fff; color: #4d5b61; font: 600 13px "DM Sans", sans-serif; cursor: pointer; }
.typical-rate-button:hover,.typical-rate-button.selected { border-color: #16bfae; color: #117d72; background: #e8f8f5; }
.typical-error-feedback p { min-height: 18px; margin: 8px 0 0; color: #198d81; font-size: 13px; }

.publication-view { padding-bottom: 54px; }
.publication-view[hidden], .blog-detail[hidden] { display: none; }
.publication-heading { max-width: 680px; margin: 14px 0 26px; }
.eyebrow { margin: 0 0 9px; color: #168f83; font-size: 12px; font-weight: 800; letter-spacing: 1.25px; }
.publication-heading h2 { margin: 0; color: #252a2f; font: 800 44px/1.1 "Nunito", sans-serif; letter-spacing: -1.2px; }
.publication-heading > p:last-child { margin: 13px 0 0; color: #68747a; font-size: 17px; line-height: 1.55; }
.publication-tabs { display: flex; gap: 25px; border-bottom: 1px solid #e1e9e7; }
.publication-tab { padding: 0 2px 13px; border: 0; border-bottom: 2px solid transparent; background: transparent; color: #7b858a; font: 700 15px "DM Sans", sans-serif; cursor: pointer; }
.publication-tab.active { border-color: #16bfae; color: #168f83; }
.blog-toolbar { display: flex; justify-content: space-between; gap: 14px; margin: 25px 0 20px; }
.blog-filters { display: flex; flex-wrap: wrap; gap: 8px; }
.blog-filter,.clear-filter { border: 1px solid #d9e7e4; border-radius: 999px; padding: 8px 12px; color: #5c686e; background: #fff; font: 600 13px "DM Sans", sans-serif; cursor: pointer; }
.blog-filter.active { border-color: #a6ddd5; color: #117d72; background: #eaf8f5; }
.clear-filter { border: 0; color: #168f83; background: transparent; }
.blog-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 18px; }
.blog-card { min-height: 332px; display: flex; flex-direction: column; overflow: hidden; border: 1px solid #e2eae8; border-radius: 17px; background: #fff; }
.card-visual { min-height: 106px; display: flex; align-items: center; justify-content: center; color: #176d65; font: 800 24px "Nunito", sans-serif; letter-spacing: -.5px; }
.math-visual { background: linear-gradient(135deg,#d9f4ee,#e9fbf8); }.study-visual { background: linear-gradient(135deg,#f3ebff,#ebeefc); color: #675292; }.exam-visual { background: linear-gradient(135deg,#fff1d3,#fff8e9); color: #986317; }.geometry-visual { background: linear-gradient(135deg,#e2f0ff,#eef7ff); color: #40749c; }
.blog-card > p { margin: 17px 17px 7px; color: #198d81; font-size: 11px; font-weight: 800; letter-spacing: .55px; text-transform: uppercase; }
.blog-card h3 { margin: 0 17px 9px; color: #2c353a; font: 800 20px/1.2 "Nunito", sans-serif; letter-spacing: -.25px; }
.blog-card > span { margin: 0 17px; color: #718087; font-size: 13px; line-height: 1.5; }
.blog-card footer { display: flex; align-items: center; justify-content: space-between; gap: 7px; margin: auto 17px 17px; padding-top: 14px; border-top: 1px solid #edf1f0; color: #899398; font-size: 12px; }
.blog-card footer button,.related-blogs button { padding: 0; border: 0; color: #168f83; background: transparent; font: 700 12px "DM Sans", sans-serif; cursor: pointer; }
.publication-empty { margin-top: 20px; min-height: 260px; place-content: center; justify-items: center; text-align: center; border: 1px dashed #cbdedb; border-radius: 18px; background: #fff; }.publication-empty[hidden] { display: none; }.publication-empty span { color: #16bfae; font-size: 25px; }.publication-empty h3 { margin: 12px 0 7px; color: #30363b; font: 800 22px "Nunito", sans-serif; }.publication-empty p { max-width: 420px; margin: 0; color: #7f898f; }.publication-empty div { display: flex; gap: 10px; margin-top: 21px; }.publication-empty button { border: 0; border-radius: 9px; padding: 10px 13px; color: #fff; background: #16bfae; font: 700 13px "DM Sans", sans-serif; cursor: pointer; }.publication-empty .text-button { color: #168f83; background: #edf9f7; }
.blog-pagination { display: flex; justify-content: center; align-items: center; gap: 17px; margin-top: 28px; color: #7d898e; font-size: 13px; }.blog-pagination button { border: 0; color: #168f83; background: transparent; font: 700 13px "DM Sans", sans-serif; cursor: pointer; }.blog-pagination button:disabled { color: #bbc3c5; cursor: not-allowed; }
.blog-detail { margin-top: 29px; }.blog-detail-layout { display: grid; grid-template-columns: minmax(0,1fr) 260px; gap: 48px; align-items: start; }.blog-article { max-width: 780px; }.blog-article h2 { margin: 0; color: #252a2f; font: 800 43px/1.1 "Nunito", sans-serif; letter-spacing: -1.15px; }.article-byline { margin: 15px 0 26px; color: #899398; font-size: 13px; }.article-byline span { margin: 0 5px; }.blog-article > section:not(.article-cta):not(.related-blogs) { margin-top: 31px; scroll-margin-top: 26px; }.blog-article > section h3,.article-cta h3,.related-blogs h3,.blog-toc h3 { margin: 0 0 11px; color: #2d3338; font: 800 25px/1.2 "Nunito", sans-serif; }.blog-article > section p { margin: 0; color: #4d575e; font-size: 16px; line-height: 1.68; }.article-cta { margin-top: 32px; padding: 22px; border-radius: 15px; background: #edf9f7; }.article-cta h3,.related-blogs h3 { font-size: 21px; }.article-cta button { margin-top: 16px; border: 0; border-radius: 9px; padding: 11px 14px; color: #fff; background: #16bfae; font: 700 13px "DM Sans", sans-serif; cursor: pointer; }.related-blogs { margin-top: 29px; }.related-blogs button { display: block; margin: 11px 0; font-size: 14px; }.blog-toc { position: sticky; top: 24px; padding: 20px; border-left: 1px solid #e2ebe9; }.blog-toc h3 { font-size: 17px; }.blog-toc button { display: block; width: 100%; margin: 9px 0; padding: 0 0 0 12px; border: 0; border-left: 2px solid #dce8e5; color: #798489; background: transparent; text-align: left; font: 13px/1.4 "DM Sans", sans-serif; cursor: pointer; }.blog-toc button.active { border-color: #16bfae; color: #168f83; font-weight: 700; }
.news-list { display: grid; gap: 13px; margin-top: 25px; }.news-item { display: grid; grid-template-columns: 115px minmax(0,1fr) 24px; gap: 22px; align-items: center; padding: 22px; border: 1px solid #e2eae8; border-radius: 15px; color: inherit; background: #fff; text-decoration: none; }.news-item:not(.unavailable):hover { border-color: #b8ddd7; box-shadow: 0 6px 18px #17252209; }.news-logo { color: #2b5c73; font: 800 19px "Nunito", sans-serif; }.news-item p { margin: 0 0 7px; color: #198d81; font-size: 11px; font-weight: 800; letter-spacing: .65px; }.news-item h3 { margin: 0 0 7px; color: #30383d; font: 800 20px/1.2 "Nunito", sans-serif; }.news-item div > span { color: #738087; font-size: 13px; line-height: 1.5; }.news-item > b { color: #168f83; font-size: 20px; }.news-item.unavailable { opacity: .65; }.news-item.unavailable > b { color: #9fa8ac; }

/* Final product sidebar alignment */
.sidebar { position: fixed; inset: 0 auto 0 0; z-index: 10; width: 360px; height: 100vh; min-height: 100vh; overflow-y: auto; padding: 28px 20px 28px 28px; box-shadow: 1px 0 0 #e3e7e7; }
.page { width: calc(100% - 360px); flex: none; margin-left: 360px; }
.brand { gap: 12px; color: #202124; font-size: 21px; }
.brand-mark { width: 38px; height: 38px; border-radius: 10px; font-size: 19px; box-shadow: inset -5px -5px 0 #48b497; }
.sidebar-collapse { position: absolute; top: 37px; right: 38px; width: 25px; height: 25px; padding: 0; border: 1px solid #cbd0d2; border-radius: 4px; color: #899197; background: #fff; font-size: 22px; line-height: 20px; cursor: pointer; }
.side-nav { margin-top: 28px; gap: 7px; }
.side-item { height: 52px; padding: 0 14px; gap: 14px; border-radius: 11px; font-size: 17px; }
.side-item:hover,.side-item.active { background: #f1f1f1; }
.nav-icon { width: 20px; color: #788187; font-size: 21px; }
.nav-divider { height: 1px; margin: 10px 7px; background: #e1e5e6; }
.plus-card { border: 1px solid #d6e4e2; border-radius: 16px; padding: 25px 21px 20px; background: #eefaf8; box-shadow: none; }
.plus-heading { font-size: 20px; }
.plus-heading strong { padding: 4px 6px; color: #8b6111; background: #ffc85c; }
.plus-rule { height: 1px; margin: 18px 0; background: #b8ddd7; }
.plus-card p { margin: 12px 0; color: #44565a; }
.plus-card button { margin-top: 8px; color: #fff; background: #118d7e; font-size: 15px; }
.topbar { justify-content: flex-end; padding-right: 36px; }
.topbar-spacer { flex: 1; }
.account-actions { display: flex; align-items: center; gap: 20px; }
.theme-switch { display: flex; align-items: center; gap: 2px; padding: 4px; border: 1px solid #dfe4e5; border-radius: 999px; background: #f4f5f5; }
.theme-option { width: 35px; height: 35px; padding: 0; border: 0; border-radius: 50%; color: #91999d; background: transparent; font-size: 20px; line-height: 35px; cursor: pointer; }
.theme-option.active { color: #fff; background: #16bfae; }
.sign-in-button { padding: 10px 0; border: 0; color: #252a2f; background: transparent; font: 700 16px "DM Sans", sans-serif; cursor: pointer; }
.get-started-button { padding: 13px 18px; border: 0; border-radius: 10px; color: #fff; background: #118d7e; font: 700 15px "DM Sans", sans-serif; cursor: pointer; }
.get-started-button:hover { background: #0d7569; }
.problem-entry { padding: 0; border: 0; box-shadow: none; background: transparent; }
.problem-entry .problem-controls { max-width: 760px; height: 68px; margin-top: 34px; padding: 0 8px 0 25px; border-radius: 999px; background: #e4edff; box-shadow: none; }
.problem-controls > input { height: 100%; padding: 0 10px 0 0; border: 0; outline: 0; background: transparent; color: #2d3543; font-size: 18px; }
.problem-controls > input:focus { outline: 0; }
.problem-controls > input::placeholder { color: #737f94; }
.upload-icon-button { display: grid; place-items: center; width: 44px; height: 44px; flex: 0 0 44px; border: 0; border-radius: 50%; color: #404b5b; background: transparent; font-size: 25px; cursor: pointer; }
.upload-icon-button:hover { background: #d5e3ff; }
.upload-icon-button input { display: none; }
.problem-control-divider { width: 1px; height: 27px; margin: 0 9px 0 3px; background: #b9c5d8; }
.problem-controls > button.problem-submit,
.problem-controls > #problem-submit { width: 48px; height: 48px; flex: 0 0 48px; padding: 0; border: 0; border-radius: 50%; color: #8c98a9; background: #fff; font-size: 31px; line-height: 48px; }
.problem-controls > #problem-submit:not(:disabled) { color: #fff; background: #16bfae; cursor: pointer; }
.problem-controls > #problem-submit:disabled { cursor: not-allowed; }
.upload-dropzone { max-width: 760px; min-height: 230px; margin-top: 16px; padding: 40px 24px; display: grid; place-items: center; align-content: center; gap: 11px; border: 2px dashed #dfe3ef; border-radius: 25px; color: #acb5d0; background: #fff; box-shadow: 0 11px 22px #26365b12; text-align: center; cursor: pointer; }
.upload-dropzone[hidden] { display: none; }
.upload-dropzone.dragging,.upload-dropzone:hover { border-color: #aabde9; background: #f9fbff; }
.dropzone-icon { color: #c0c7df; font-size: 42px; line-height: 1; }
.upload-dropzone strong { color: #b0b8d3; font-size: 20px; font-weight: 500; }
.upload-dropzone strong b { color: #2d3762; font-weight: 500; }
.upload-dropzone > span:last-child { font-size: 18px; }
.upload-dropzone > span:last-child b { padding: 2px 7px; border: 1px solid #ccd2e4; border-radius: 7px; color: #a9b2ce; }
.problem-file-name { max-width: 760px; margin: 9px 0 0; }
.problem-status { max-width: 760px; margin: 3px 0 0; }
.level-3 { margin: 0 0 11px 22px; border: 1px solid #dfe9ea; border-radius: 14px; box-shadow: none; }
.level-3 > .accordion-trigger { height: 60px; padding: 0 22px; background: #f8fcfb; font-size: 16px; }
.knowledge-question-content { padding: 0 14px 10px; background: #fff; }
.knowledge-question-link { width: 100%; min-height: 54px; height: auto; margin: 0; padding: 12px 14px; border: 0; border-bottom: 1px solid #edf1f1; border-radius: 0; background: transparent; box-shadow: none; font-size: 14px; line-height: 1.4; }
.knowledge-question-link:last-child { border-bottom: 0; }
.knowledge-question-link span:first-child { max-width: calc(100% - 30px); }
.knowledge-question-link:hover { background: #f2faf8; }
.knowledge-question-content .detail-link.knowledge-entry-link { width: 100%; min-height: 54px; height: auto; margin: 0; padding: 12px 14px; border: 0; border-bottom: 1px solid #edf1f1; border-radius: 0; background: transparent; box-shadow: none; font: 400 14px/1.4 "DM Sans", sans-serif; }
.knowledge-question-content .detail-link.knowledge-entry-link:last-of-type { border-bottom: 0; }
.knowledge-question-content .detail-link.knowledge-entry-link:hover { background: #f2faf8; }
.knowledge-question-content .detail-link.knowledge-entry-link b { font-weight: 400; }
.level4-empty { margin: 8px 3px 2px; color: #9aa3aa; font-size: 13px; }
.subject-question-list[hidden] { display: none; }
.subject-question-list .question-link { min-height: 94px; height: auto; padding: 20px 33px; line-height: 1.45; }
.subject-question-list .question-link span:first-child { max-width: calc(100% - 34px); }

@media (max-width: 850px) {
  .sidebar { position: static; width: 76px; height: auto; min-height: 100vh; padding: 22px 9px; }
  .page { width: auto; flex: 1; margin-left: 0; }
  .sidebar-collapse { display: none; }
  .topbar { padding-right: 18px; }
  .account-actions { gap: 10px; }
  .theme-switch { display: none; }
  .get-started-button { padding: 10px 12px; }
}

/* body zoom is used on short desktop viewports; compensate the fixed sidebar
   so its visual height still reaches the browser bottom. */
@media (min-width: 851px) and (max-height: 950px) {
  .sidebar { height: calc(100vh / .68); min-height: calc(100vh / .68); }
}

@media (min-width: 851px) and (max-height: 760px) {
  .sidebar { height: calc(100vh / .58); min-height: calc(100vh / .58); }
}

@media (max-width: 850px) {
  .problem-controls { flex-wrap: wrap; }
  .problem-controls > input { flex-basis: 100%; }
  .empty-state-actions { flex-direction: column; width: 100%; }
  .knowledge-layout { grid-template-columns: 1fr; gap: 28px; }
  .question-layout { grid-template-columns: 1fr; }
  .question-layout > .related-card { position: static; }
  .knowledge-article h2 { font-size: 34px; }
  .knowledge-misconceptions,.knowledge-next-grid { grid-template-columns: 1fr; }
  .knowledge-entry-copy { padding: 14px 16px; font-size: 18px; }
  .question-article h2 { font-size: 33px; }
  .subject-question-list .question-link { padding: 17px 20px; font-size: 16px; }
  .demo-access { align-items: flex-start; flex-direction: column; }
  .concept-grid { grid-template-columns: 1fr; }
  .blog-grid { grid-template-columns: 1fr; }
  .blog-detail-layout { grid-template-columns: 1fr; gap: 26px; }
  .blog-toc { position: static; order: -1; border-left: 0; border-bottom: 1px solid #e2ebe9; }
  .news-item { grid-template-columns: 1fr 22px; gap: 12px; }.news-logo { grid-column: 1 / -1; }
  .lock-in-grid { grid-template-columns: 1fr; }
}