/* Developmentally adaptive learner surface. Academic/governance data stays outside study mode. */
  body.student-study-active .academic-evidence,
  body.student-study-active .question-academic-meta,
  body.student-study-active .coverage-chip,
  body.student-study-active .concept-written-chip{display:none!important;}

  .concept-card,.practice-card,.session-summary,.construction-card{transition:none!important;}
  .concept-card .concept-stage-kicker{font:750 .72rem/1.35 var(--font-ui);letter-spacing:.03em;color:#786541;margin-bottom:7px;}
  .concept-card .concept-idea{line-height:1.65;}
  .student-task-box{margin-top:14px;padding:14px 16px;border-radius:12px;background:#f6f3e8;border:1px solid #ddd3ba;}
  .student-task-box h5{margin:0 0 8px;color:#4c453a;}
  .student-task-box ul{margin:0;padding-left:1.2rem;}
  .student-task-box li+li{margin-top:6px;}
  .age-note{font-size:.76rem;color:var(--ink-soft);margin:9px 0 0;}
  .practice-head{justify-content:flex-start!important;}
  .practice-head .qnum{font-weight:750;}
  .practice-support-row{margin-top:10px;}
  .hint-btn{border-radius:999px!important;}
  .student-study-active .revisit-guide .academic-source-links,
  .student-study-active .mapped-review-card .academic-source-links{display:none!important;}
  .student-study-active .revisit-guide{background:#f7f4e9;border:1px solid #dfd4bc;border-radius:12px;padding:12px 14px;margin-top:12px;}
  .revisit-title{font-weight:800;margin-bottom:4px;}
  .revisit-path{font-size:.78rem;color:#665f53;}
  .revisit-focus{margin-top:5px;line-height:1.5;}

  /* Classes 1–2: one idea at a time, large controls, minimal text. */
  body[data-learning-band="early"] #chat{max-width:760px;}
  body[data-learning-band="early"] .concept-card,
  body[data-learning-band="early"] .practice-card{font-size:1.06rem;line-height:1.7;padding:22px 22px;border-radius:18px;}
  body[data-learning-band="early"] .concept-card h4{font-size:1.55rem;line-height:1.2;margin-bottom:12px;}
  body[data-learning-band="early"] .concept-section h5,
  body[data-learning-band="early"] .student-task-box h5{font-size:1.05rem;}
  body[data-learning-band="early"] .concept-card ul{padding-left:1.25rem;}
  body[data-learning-band="early"] .choice-btn{min-height:58px;font-size:1rem;border-radius:15px;}
  body[data-learning-band="early"] .practice-answer-row input{min-height:52px;font-size:1.08rem;}
  body[data-learning-band="early"] .submit-ans{min-height:52px;font-size:1rem;}
  body[data-learning-band="early"] .hint-btn{min-height:46px;font-size:.95rem;}
  body[data-learning-band="early"] .narrate-btn{font-size:.9rem;padding:9px 13px;}
  body[data-learning-band="early"] .breadcrumb .study-course-context{display:none!important;}
  body[data-learning-band="early"] .breadcrumb .tag{font-size:.98rem!important;}
  body[data-learning-band="early"] #modalOverlay .chapter-list button{min-height:58px;font-size:1rem;}
  body[data-learning-band="early"] #modalOverlay .chapter-list button .num{display:none;}

  /* Classes 3–5: visual/activity-led, still generous spacing and plain language. */
  body[data-learning-band="primary"] #chat{max-width:820px;}
  body[data-learning-band="primary"] .concept-card,
  body[data-learning-band="primary"] .practice-card{font-size:1rem;line-height:1.68;padding:20px;border-radius:16px;}
  body[data-learning-band="primary"] .concept-card h4{font-size:1.38rem;}
  body[data-learning-band="primary"] .choice-btn{min-height:52px;font-size:.96rem;}
  body[data-learning-band="primary"] .practice-answer-row input,
  body[data-learning-band="primary"] .submit-ans{min-height:48px;}
  body[data-learning-band="primary"] .narrate-btn{font-size:.82rem;}

  /* Classes 6–8: discovery + structured practice. */
  body[data-learning-band="middle"] #chat{max-width:900px;}
  body[data-learning-band="middle"] .concept-card,
  body[data-learning-band="middle"] .practice-card{font-size:.95rem;line-height:1.62;}
  body[data-learning-band="middle"] .choice-btn{min-height:48px;}

  /* Classes 9–10: rigorous but readable. */
  body[data-learning-band="secondary"] #chat{max-width:980px;}
  body[data-learning-band="secondary"] .concept-card,
  body[data-learning-band="secondary"] .practice-card{font-size:.93rem;line-height:1.58;}
  body[data-learning-band="secondary"] .concept-card h4{font-size:1.25rem;}
  body[data-learning-band="secondary"] .narrate-row{opacity:.8;}

  /* Classes 11–12: denser academic reference, without governance clutter. */
  body[data-learning-band="senior"] #chat{max-width:1040px;}
  body[data-learning-band="senior"] .concept-card,
  body[data-learning-band="senior"] .practice-card{font-size:.92rem;line-height:1.55;}
  body[data-learning-band="senior"] .concept-section{margin-top:15px;}
  body[data-learning-band="senior"] .concept-formulae{font-size:1rem;}
  body[data-learning-band="senior"] .narrate-row{opacity:.65;}

  @media(max-width:620px){
    body[data-learning-band="early"] .concept-card,
    body[data-learning-band="early"] .practice-card,
    body[data-learning-band="primary"] .concept-card,
    body[data-learning-band="primary"] .practice-card{padding:17px 15px;}
    .student-task-box{padding:12px 13px;}
    .revisit-path{font-size:.72rem;}
  }


/* ---------- Foundation-first chapter entry ---------- */
.foundation-card{
  width:min(760px,calc(100% - 28px));margin:28px auto 42px;padding:24px 26px;
  border:1px solid #d8cfbb;border-radius:18px;background:#fffdf7;color:#332f29;
  box-shadow:0 10px 30px rgba(47,61,52,.08);
}
.foundation-kicker{font:800 .7rem/1.35 var(--font-ui);letter-spacing:.075em;color:#8a6a2f;margin-bottom:8px;}
.foundation-card h3{margin:0 0 10px;font:750 clamp(1.35rem,2.8vw,1.8rem)/1.18 var(--font-display);color:#203b32;}
.foundation-assurance{margin:0 0 18px;line-height:1.62;color:#5c564c;}
.foundation-block{margin:14px 0;padding:14px 16px;border-radius:12px;background:#f8f4e9;border:1px solid #e2d9c5;}
.foundation-block h4{margin:0 0 8px;font-size:.9rem;color:#3d5149;}
.foundation-block p,.foundation-block ul{margin:0;line-height:1.62;font-size:.9rem;}
.foundation-help{margin:0 0 9px!important;color:#6b6459;font-size:.82rem!important;}
.foundation-block ul{padding-left:1.2rem;}.foundation-block li+li{margin-top:6px;}
.foundation-first-step{background:#f1f7f2;border-color:#cadfce;}
.foundation-warmup{margin:16px 0;padding:15px 16px;border-left:4px solid #d79125;background:#fff8e9;border-radius:4px 12px 12px 4px;}
.foundation-warmup-label,.foundation-bridge>span{display:block;margin-bottom:5px;font:800 .72rem/1.3 var(--font-ui);letter-spacing:.025em;color:#7b5e2c;}
.foundation-warmup p,.foundation-bridge p{margin:0;line-height:1.62;font-size:.9rem;}
.foundation-bridge{margin:14px 0 18px;padding:12px 14px;border-top:1px solid #e4dccb;border-bottom:1px solid #e4dccb;}
.foundation-actions{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:18px;}
.foundation-continue{border:0;border-radius:999px;min-height:44px;padding:11px 18px;background:#d98c20;color:#211709;font-weight:800;cursor:pointer;}
.foundation-skip{border:0;background:transparent;color:#4f655c;text-decoration:underline;text-underline-offset:3px;font-weight:700;padding:10px 6px;cursor:pointer;}
body[data-learning-band="early"] .foundation-card{max-width:640px;padding:28px 24px;}
body[data-learning-band="early"] .foundation-card h3{font-size:1.55rem;}
body[data-learning-band="early"] .foundation-assurance,body[data-learning-band="early"] .foundation-block p,body[data-learning-band="early"] .foundation-block li,body[data-learning-band="early"] .foundation-warmup p{font-size:1rem;}
body[data-learning-band="early"] .foundation-continue{min-height:52px;font-size:1rem;padding:13px 22px;}
@media(max-width:640px){
  .foundation-card{width:calc(100% - 18px);margin:16px auto 28px;padding:18px 15px;border-radius:15px;}
  .foundation-block{padding:12px 13px;}
  .foundation-actions{display:grid;grid-template-columns:1fr;}
  .foundation-continue,.foundation-skip{width:100%;}
}

/* ---------- Textbook-led chapter flow ---------- */
#preferencesOverlay{z-index:170;}
.chapter-textbook-link{
  display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:8px 11px;
  border:1px solid rgba(255,255,255,.24);border-radius:999px;color:#fff9e9;text-decoration:none;
  font:750 .76rem/1 var(--font-ui);background:rgba(255,255,255,.07);white-space:nowrap;
}
.chapter-textbook-link:hover,.chapter-textbook-link:focus-visible{background:rgba(255,255,255,.13);outline:2px solid #f0b54b;outline-offset:2px;}
.chapter-opening-card{
  width:min(820px,calc(100% - 28px));margin:24px auto 36px;padding:24px;
  background:#fffdf7;border:1px solid #ddd2bd;border-radius:18px;box-shadow:0 12px 28px rgba(22,48,42,.08);
}
.textbook-source{
  display:flex;align-items:center;justify-content:space-between;gap:16px;padding:12px 14px;margin-bottom:18px;
  background:#f4efe3;border:1px solid #ddd2bd;border-radius:12px;
}
.textbook-source.compact{margin:-2px 0 16px;padding:10px 12px;}
.textbook-source-copy{display:flex;flex-direction:column;gap:2px;min-width:0;color:#514b41;}
.textbook-source-copy strong{font:750 .86rem/1.35 var(--font-ui);color:#243f36;overflow-wrap:anywhere;}
.textbook-source-copy>span:not(.textbook-source-kicker){font-size:.72rem;line-height:1.35;color:#746b5d;}
.textbook-source-kicker{font:800 .62rem/1.2 var(--font-ui);letter-spacing:.07em;color:#8a6a2f;}
.source-online-note{font-style:italic;}
.official-chapter-link{display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:8px 12px;border-radius:999px;border:1px solid #b79b62;text-decoration:none;color:#294c40;font-weight:800;font-size:.76rem;white-space:nowrap;background:#fff;}
.official-chapter-link:hover,.official-chapter-link:focus-visible{background:#fff8e8;outline:2px solid #d99426;outline-offset:2px;}
.chapter-page-meta{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:8px;font:750 .7rem/1.35 var(--font-ui);color:#7a705f;text-transform:uppercase;letter-spacing:.035em;}
.chapter-opening-card h3{margin:0 0 10px;font:750 clamp(1.45rem,3vw,2rem)/1.16 var(--font-display);color:#203b32;}
.chapter-opening-intro{margin:0 0 18px;font-size:1rem;line-height:1.68;color:#4f4a42;}
.chapter-roadmap{margin:18px 0;padding:16px 17px;background:#f8f5ec;border:1px solid #e2d9c5;border-radius:13px;}
.chapter-roadmap-head{display:flex;align-items:baseline;justify-content:space-between;gap:10px;margin-bottom:10px;}
.chapter-roadmap h4{margin:0;font-size:.92rem;color:#31483f;}
.chapter-roadmap-head span{font-size:.68rem;color:#867b68;}
.chapter-roadmap ol{margin:0;padding-left:1.35rem;columns:2;column-gap:34px;}
.chapter-roadmap li{break-inside:avoid;margin:0 0 8px;line-height:1.45;font-size:.86rem;}
.roadmap-note{margin:10px 0 0;font-size:.74rem;line-height:1.5;color:#786f61;}
.chapter-refresher{margin:16px 0;border-top:1px solid #e4dccb;border-bottom:1px solid #e4dccb;padding:4px 0;}
.chapter-refresher summary{cursor:pointer;padding:10px 2px;font-weight:800;font-size:.82rem;color:#456056;}
.chapter-refresher-body{padding:2px 8px 12px;font-size:.82rem;line-height:1.55;color:#5d574d;}
.chapter-refresher-body p{margin:6px 0;}.chapter-refresher-body ul{margin:6px 0;padding-left:1.2rem;}
.chapter-opening-actions{margin-top:16px;}
.book-learning-card{width:min(820px,calc(100% - 28px));margin:24px auto 36px;padding:20px;background:#fffdf8;border:1px solid #ddd2bd;border-radius:18px;box-shadow:0 12px 28px rgba(22,48,42,.08);}
.book-page-shell{min-height:330px;display:flex;flex-direction:column;}
.book-page-status{font:800 .68rem/1.35 var(--font-ui);letter-spacing:.045em;color:#82765f;text-transform:uppercase;padding:2px 2px 12px;border-bottom:1px solid #e6dece;}
.book-page-content{flex:1;padding:22px 6px 20px;}
.book-page-content h4{margin:3px 0 13px;font:750 clamp(1.35rem,2.6vw,1.8rem)/1.2 var(--font-display);color:#203b32;}
.book-page-body{font-size:1rem;line-height:1.72;color:#47433d;}
.book-page-body p{margin:0;}.book-page-body ul{padding-left:1.25rem;}.book-page-body li+li{margin-top:8px;}
.book-page-actions{display:flex;align-items:center;justify-content:space-between;gap:10px;border-top:1px solid #e6dece;padding-top:14px;}
.book-page-actions button{min-height:42px;padding:9px 16px;border-radius:999px;font-weight:800;cursor:pointer;}
.book-page-prev{background:#fff;border:1px solid #cfc5b3;color:#45564f;}.book-page-prev:disabled{opacity:.38;cursor:default;}
.book-page-next{border:0;background:#d98c20;color:#211709;}
.book-page-narration{margin-top:18px!important;}
@media(max-width:720px){
  .chapter-roadmap ol{columns:1;}
  .textbook-source{align-items:flex-start;flex-direction:column;gap:9px;}
  .official-chapter-link{width:100%;}
}
@media(max-width:640px){
  .chapter-textbook-link{min-height:36px;font-size:.69rem;padding:7px 9px;}
  .chapter-opening-card,.book-learning-card{width:calc(100% - 16px);margin:12px auto 24px;padding:15px;border-radius:14px;}
  .chapter-opening-intro,.book-page-body{font-size:.94rem;}
  .book-page-content{padding:17px 2px 16px;}
  .book-page-actions{display:grid;grid-template-columns:1fr 1fr;}
  .book-page-actions button{width:100%;}
}
@media(max-width:390px){
  .chapter-textbook-link{font-size:0;width:auto;min-width:42px;}
  .chapter-textbook-link::before{content:'Book ↗';font-size:.69rem;}
  .chapter-page-meta{font-size:.64rem;}
}
#aboutOverlay,#privacyOverlay{z-index:180;}
@media(max-width:520px){.study-switches .chapter-textbook-link{flex:1;min-width:0;}}

/* Grade-specific textbook flow */
.grade-learning-cue{margin:12px 0 14px;padding:11px 13px;border:1px solid #ddd4c2;border-radius:12px;background:#fbf8f1;color:#4f544d;font-size:.86rem;line-height:1.55;}
.grade-learning-cue strong{color:#2f4b41;}
.refresher-source-note{font-size:.75rem;color:#766f63;}
.official-section-explainer{margin:0 0 12px;color:#6a655b;font-size:.82rem;line-height:1.55;}
.section-understanding{margin:12px 0;padding:12px 14px;border-left:3px solid #d18a25;background:#fcf7ee;border-radius:0 10px 10px 0;}
.section-understanding strong{display:block;margin-bottom:5px;color:#315248;font-size:.78rem;text-transform:uppercase;letter-spacing:.04em;}
.section-understanding p{margin:0;}
.representation-cue,.grade-activity-card{margin:14px 0;padding:12px 14px;border:1px dashed #c9bea9;border-radius:12px;background:#fffdf8;color:#514d46;line-height:1.6;}
.grade-activity-card p{margin:0 0 8px;}.grade-activity-card ul{margin:7px 0 0;padding-left:1.2rem;}
.page-source-return{margin-top:18px;padding-top:12px;border-top:1px solid #e5dece;display:flex;align-items:flex-start;justify-content:space-between;gap:12px;font-size:.76rem;color:#776f62;}
.page-source-return a{font-weight:800;color:#31584a;text-decoration:none;white-space:nowrap;}.page-source-return a:hover{text-decoration:underline;}
.practice-head{display:flex;align-items:center;justify-content:space-between;gap:10px;}
.practice-level{font:800 .68rem/1.2 var(--font-ui);letter-spacing:.035em;padding:5px 9px;border-radius:999px;background:#f2eee5;color:#665e52;border:1px solid #ded5c5;white-space:nowrap;}
.practice-level.level-1{background:#f4f7f3;color:#3e5a4f;}.practice-level.level-2{background:#fbf5e9;color:#785c2e;}.practice-level.level-3{background:#f5f0ea;color:#675344;}.practice-level.level-4{background:#f1eef5;color:#5a4e67;}
body[data-learning-band="early"] .book-page-content{padding-top:16px;}body[data-learning-band="early"] .book-page-content h4{font-size:1.3rem;}body[data-learning-band="early"] .book-page-body{font-size:1rem;line-height:1.65;}
body[data-learning-band="primary"] .book-page-body{line-height:1.68;}
@media(max-width:520px){.page-source-return{display:block}.page-source-return a{display:inline-block;margin-bottom:5px}.grade-learning-cue,.representation-cue,.grade-activity-card{padding:10px 11px}.practice-head{align-items:flex-start}}

/* Academic-integrity source-only state */
[hidden]{display:none!important;}
.source-only-chapter-card{width:min(820px,calc(100% - 28px));margin:22px auto 34px;padding:24px 26px;background:#fffdf8;border:1px solid rgba(35,77,64,.16);border-radius:18px;box-shadow:0 8px 24px rgba(22,48,42,.07);}
.source-only-chapter-card h2{margin:18px 0 12px;color:#16302a;font-size:clamp(1.35rem,2.4vw,2rem);line-height:1.18;}
.source-only-sections{margin:18px 0;padding:16px 18px;background:#f7f5ec;border-radius:14px;border:1px solid rgba(35,77,64,.1);}
.source-only-sections h4{margin:0 0 10px;font-size:.85rem;text-transform:uppercase;letter-spacing:.04em;color:#536a61;}
.source-only-sections ol{margin:0;padding-left:1.35rem;display:grid;gap:7px;}
.academic-integrity-notice{margin:18px 0;padding:16px 18px;border-left:4px solid #8d6f32;background:#fbf6e8;border-radius:10px;color:#34453f;}
.academic-integrity-notice strong{display:block;color:#493d25;margin-bottom:6px;}
.academic-integrity-notice p{margin:0;line-height:1.55;font-size:.92rem;}
.source-only-actions{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:20px;}
.source-only-open,.source-only-chapters{appearance:none;border:0;border-radius:12px;padding:10px 14px;font:inherit;font-weight:700;text-decoration:none;cursor:pointer;}
.source-only-open{background:#234d40;color:#fff;}
.source-only-chapters{background:#eef2ee;color:#234d40;border:1px solid rgba(35,77,64,.18);}
@media(max-width:600px){
  .source-only-chapter-card{width:calc(100% - 18px);margin:10px auto 22px;padding:17px 15px;border-radius:14px;}
  .source-only-actions{display:grid;grid-template-columns:1fr;}
  .source-only-open,.source-only-chapters{text-align:center;width:100%;box-sizing:border-box;}
  .academic-integrity-notice{padding:14px;}
}


/* Professional courseware core: textbook sequence, Vidyut teaching, minimal chrome */
body.student-study-active .page-wrap{background:#f4f1e8;}
body.student-study-active .page-wrap::before,
body.student-study-active .page-wrap::after{display:none;}
body.student-study-active #chat{max-width:none!important;padding:24px clamp(14px,3.4vw,54px) 40px!important;}
.chapter-opening-card,.book-learning-card,.source-only-chapter-card{width:min(960px,calc(100% - 12px));box-sizing:border-box;}
.chapter-opening-card,.book-learning-card{background:#fffefa;border-color:#ddd5c7;box-shadow:0 10px 30px rgba(25,48,41,.07);}
.book-learning-card{padding:clamp(18px,2.7vw,30px);}
.book-page-top{display:grid;gap:8px;padding-bottom:12px;border-bottom:1px solid #e4ddcf;}
.book-page-status{padding:0;border:0;text-transform:none;font-size:.76rem;letter-spacing:0;color:#6f685d;}
.book-progress{height:4px;border-radius:999px;background:#eee8dc;overflow:hidden;}
.book-progress span{display:block;height:100%;width:0;border-radius:inherit;background:#d28b26;transition:width .18s ease;}
.book-page-content{padding:26px clamp(2px,1vw,10px) 24px;}
.book-page-content>h4,.book-page-body{max-width:790px;margin-left:auto;margin-right:auto;}
.book-page-content>h4{font-size:clamp(1.42rem,2.5vw,1.92rem);}
.book-page-body{color:#333d38;}
.verified-explanation{font-size:1.04rem;line-height:1.76;color:#33423c;margin-bottom:18px;}
.verified-vocabulary,.verified-definitions,.verified-keypoints,.verified-formulae,.verified-representation,.verified-activity,.verified-worked,.verified-error,.courseware-visual,.inline-check{margin:16px 0;padding:15px 17px;border-radius:13px;border:1px solid #e0d8ca;background:#fbf9f3;}
.verified-vocabulary strong,.verified-definitions strong,.verified-keypoints strong,.verified-formulae strong,.verified-representation strong,.verified-activity strong,.verified-worked strong,.verified-error strong,.courseware-visual>strong,.inline-check>strong{display:block;margin-bottom:8px;color:#26483d;font-size:.82rem;letter-spacing:.015em;}
.verified-vocabulary ul,.verified-definitions ul,.verified-keypoints ul{margin:0;padding-left:1.2rem;display:grid;gap:6px;}
.verified-formulae{background:#f5f1e8;font-family:ui-monospace,SFMono-Regular,Consolas,monospace;line-height:1.7;overflow-x:auto;}
.verified-activity{border-left:4px solid #d28b26;background:#fff9ec;}
.verified-error{border-left:4px solid #9e6c35;background:#fcf6ed;}
.visual-chips{display:flex;gap:8px;flex-wrap:wrap;}
.visual-chips span{padding:8px 11px;border-radius:999px;background:#edf4ef;border:1px solid #cfded4;color:#24483b;font-weight:700;font-size:.85rem;}
.courseware-visual.flow ol{display:flex;align-items:stretch;gap:8px;list-style:none;margin:10px 0 0;padding:0;flex-wrap:wrap;counter-reset:step;}
.courseware-visual.flow li{counter-increment:step;position:relative;padding:10px 12px 10px 36px;border-radius:10px;background:#f0f4f0;border:1px solid #d7e0da;font-size:.86rem;font-weight:650;}
.courseware-visual.flow li::before{content:counter(step);position:absolute;left:10px;top:9px;width:19px;height:19px;border-radius:50%;display:grid;place-items:center;background:#2e5a4a;color:white;font-size:.68rem;}
.visual-table-wrap{overflow-x:auto;}
.courseware-visual table{border-collapse:collapse;width:100%;font-size:.86rem;}
.courseware-visual th,.courseware-visual td{border:1px solid #ded7ca;padding:9px 10px;text-align:left;vertical-align:top;}
.courseware-visual th{background:#f1eee5;color:#324a41;}
.inline-check{background:#f3f7f3;border-color:#d1dfd5;}
.inline-check p{margin:0 0 11px;font-weight:650;color:#2e4039;}
.inline-check-options{display:grid;gap:8px;}
.inline-check-options button{appearance:none;text-align:left;border:1px solid #cbd7ce;background:#fff;border-radius:11px;padding:10px 12px;color:#263a33;font:650 .9rem/1.35 var(--font-ui);cursor:pointer;}
.inline-check-options button:hover{background:#f7faf7;border-color:#8cab9b;}
.inline-check-options button.is-correct{background:#e8f4eb;border-color:#6ca37d;}
.inline-check-options button.is-wrong{background:#fff0eb;border-color:#c78670;}
.inline-check-feedback{margin-top:10px;padding:10px 12px;border-radius:10px;font-size:.86rem;line-height:1.5;}
.inline-check-feedback.correct{background:#e8f4eb;color:#245038;}
.inline-check-feedback.wrong{background:#fff1eb;color:#714233;}
.inline-check-wrong-title{font-weight:700;}
.inline-check-hint-btn{appearance:none;margin-top:8px;border:1px solid #b98b70;background:#fffaf6;color:#653e2f;border-radius:999px;padding:7px 12px;font:700 .82rem/1.2 var(--font-ui);cursor:pointer;}
.inline-check-hint-btn:hover{background:#fff4ec;border-color:#986a52;}
.inline-check-hint-btn:focus-visible{outline:3px solid rgba(120,82,63,.22);outline-offset:2px;}
.inline-check-hint-text{margin-top:9px;padding-top:9px;border-top:1px solid rgba(113,66,51,.18);}

.inline-check-review-btn{appearance:none;margin-top:10px;border:1px solid #b98b70;background:#fffaf6;color:#653e2f;border-radius:999px;padding:7px 12px;font:700 .82rem/1.2 var(--font-ui);cursor:pointer;}
.inline-check-review-btn:hover{background:#fff4ec;border-color:#986a52;}
.inline-check-review-btn:focus-visible{outline:3px solid rgba(120,82,63,.22);outline-offset:2px;}

.inline-check-return-btn{appearance:none;margin:8px 0 12px;border:1px solid rgba(93,117,102,.35);background:#fbfdfb;color:var(--ink-soft);border-radius:999px;padding:7px 12px;font:700 .78rem/1.2 var(--font-ui);cursor:pointer;}
.inline-check-return-btn:hover{background:#f2f7f3;}
.inline-check-return-btn:focus-visible{outline:3px solid rgba(93,117,102,.18);outline-offset:2px;}


.chapter-source-row{display:flex;justify-content:flex-start;margin-bottom:11px;}
.source-line{display:inline-flex;align-items:center;gap:4px;color:#47655a;text-decoration:none;font:750 .76rem/1.35 var(--font-ui);}
a.source-line:hover{text-decoration:underline;}
.chapter-roadmap{background:#f7f5ef;}
.chapter-roadmap ol{columns:1;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px 24px;}
.chapter-roadmap li{margin:0;}
.study-home-availability{font-size:.82rem!important;color:#746d61!important;margin-top:-4px!important;}
#modalOverlay .chapter-list button{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:8px 10px;}
#modalOverlay .chapter-list button .chapter-picker-title{min-width:0;}
.chapter-availability{justify-self:end;border-radius:999px;padding:4px 8px;font:750 .64rem/1.1 var(--font-ui);white-space:nowrap;}
.chapter-availability.ready{background:#e8f2eb;color:#2c6043;border:1px solid #c9dfd0;}
.chapter-availability.pending{background:#f3efe6;color:#766c5c;border:1px solid #e1d8c8;}
#modalOverlay .chapter-list button.chapter-pending{opacity:.8;}
.pending-lead{font-size:1.02rem;line-height:1.65;color:#3f4e48;max-width:700px;}
.pending-note{font-size:.84rem;line-height:1.55;color:#6b665d;max-width:720px;}
.pending-outline{margin:16px 0;padding:15px 17px;border:1px solid #e1dacd;border-radius:13px;background:#faf8f2;max-width:760px;}
.pending-outline h3{margin:0 0 9px;font-size:.82rem;text-transform:uppercase;letter-spacing:.04em;color:#5b6a63;}
.pending-outline ol{margin:0;padding-left:1.25rem;display:grid;gap:5px;color:#4b554f;font-size:.86rem;}
.source-only-open.secondary{background:transparent;color:#426256;border:1px solid #c9d3cc;}
.source-only-chapters{background:#234d40;color:#fff;border-color:#234d40;}
@media(max-width:700px){
  body.student-study-active #chat{padding:10px 8px 24px!important;}
  .chapter-opening-card,.book-learning-card,.source-only-chapter-card{width:100%;margin:8px auto 18px;border-radius:14px;}
  .chapter-roadmap ol{grid-template-columns:1fr;}
  #modalOverlay .chapter-list button{grid-template-columns:auto minmax(0,1fr);}
  .chapter-availability{grid-column:2;justify-self:start;}
  .verified-explanation{font-size:.98rem;}
}
@media(max-width:390px){
  .book-learning-card{padding:14px 12px;}
  .verified-vocabulary,.verified-definitions,.verified-keypoints,.verified-formulae,.verified-representation,.verified-activity,.verified-worked,.verified-error,.courseware-visual,.inline-check{padding:12px;}
  .book-page-actions{gap:8px;}
}

/* Release-state controls: hidden means absent, not merely disabled. */
.nav-group .nav-btn[hidden],
.header-actions button[hidden]{display:none!important;}
#conceptBtn[hidden],#practiceBtn[hidden]{display:none!important;}
.breadcrumb .nav-btn#conceptBtn[hidden],.breadcrumb .nav-btn#practiceBtn[hidden]{display:none!important;}

.verified-keypoints{background:#f7faf7;border-color:#d8e3dc;}
.verified-worked ol{margin:.65rem 0 .4rem;padding-left:1.25rem;display:grid;gap:.42rem;}
.worked-problem{font-weight:650;color:#263d35;}
.worked-answer{margin:.7rem 0 0;color:#26483d;}

.courseware-evidence{display:flex;align-items:flex-start;gap:10px;margin:14px 0 17px;padding:11px 13px;border:1px solid #d8dfd9;border-radius:11px;background:#f7faf7;color:#42534c;font-size:.78rem;line-height:1.45;}
.courseware-evidence strong{flex:0 0 auto;color:#24483b;font-size:.73rem;letter-spacing:.015em;}
.courseware-evidence.baseline{background:#faf8f2;border-color:#e2dacb;}
.courseware-evidence.baseline strong{color:#6d572f;}
.courseware-evidence span{min-width:0;}
@media(max-width:560px){.courseware-evidence{display:grid;gap:4px;}}

.textbook-crossmap{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:-3px 0 10px;font-size:.74rem;line-height:1.35;color:#6c6458;}
.textbook-crossmap span{font-weight:750;}
.textbook-crossmap a{color:#47655a;text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:2px;}

/* PC1.4: explicit official-book reference on quick-check recovery */
.inline-check-source-ref{margin-top:10px;padding:10px 11px;border:1px solid rgba(113,66,51,.18);border-radius:10px;background:rgba(255,255,255,.55);color:#5f3d31;}
.inline-check-source-ref>strong{display:block;margin-bottom:4px;color:#503127;}
.inline-check-source-meta{margin-bottom:4px;font-weight:650;}
.inline-check-source-pages{margin-top:2px;}
.inline-check-source-link{display:inline-block;margin-top:7px;color:#56392f;font-weight:750;text-decoration:underline;text-underline-offset:2px;}
.inline-check-source-link:hover{text-decoration-thickness:2px;}
.inline-check-source-link:focus-visible{outline:3px solid rgba(120,82,63,.22);outline-offset:3px;border-radius:4px;}

/* PC1.5 precision source tracing */
.inline-check-source-status{display:inline-flex;margin:2px 0 7px;padding:3px 8px;border-radius:999px;border:1px solid rgba(77,91,67,.20);background:rgba(246,250,242,.82);font-size:.78rem;font-weight:760;color:#42503d;}
.inline-check-source-pending{margin:6px 0 8px;padding:8px 9px;border-radius:8px;background:rgba(255,248,230,.78);font-size:.9rem;line-height:1.45;color:#674d2d;}
.inline-check-source-item{margin-top:8px;padding-top:8px;border-top:1px solid rgba(113,66,51,.12);}
.inline-check-source-item:first-of-type{border-top:0;padding-top:2px;}
.inline-check-source-section{line-height:1.45;color:#4c3027;}
.inline-check-source-element{margin-top:3px;font-size:.9rem;line-height:1.45;}
.verified-source-trace{margin:14px 0 12px;border:1px solid rgba(82,97,76,.15);border-radius:12px;background:rgba(248,251,246,.64);}
.verified-source-trace>summary{cursor:pointer;padding:9px 11px;font-weight:720;color:#465144;}
.verified-source-trace>.inline-check-source-ref{margin:0 9px 9px;background:rgba(255,255,255,.58);}
@media (max-width:640px){.inline-check-source-ref{padding:9px}.inline-check-source-meta{font-size:.9rem}.inline-check-source-link{padding:2px 0}}


/* PC2.2 chapter availability states */
.chapter-availability.review{background:#fff3d9;color:#765315;border:1px solid #efd7a0;}
.chapter-availability.gap{background:#f5ece8;color:#7a4030;border:1px solid #e1c8bd;}
.chapter-availability.error{background:#fbe7e5;color:#7d332e;border:1px solid #e5b5b0;}
#modalOverlay .chapter-list button[data-availability="quality-review"],
#modalOverlay .chapter-list button[data-availability="source-gap"]{opacity:1;}
#modalOverlay .chapter-list button[data-availability="quality-review"]:hover{background:#fff8e8;}
#modalOverlay .chapter-list button[data-availability="source-gap"]:hover{background:#fbf2ed;}