/* =================================================================
   cbse-frontend/css/cbse.css — layout for the CBSE app pages (class hubs,
   chapter pages, Route to 95, teacher tools, info pages).
   Colours, type, buttons, chips, panels, tiles and progress bars come from
   css/tokens.css (load it first); the question card is the site's standard
   card from css/unit-ux.css (body.unit-ux). Only `cb-` classes here, no
   per-site colours.
   ================================================================= */
body.cb { margin: 0; font-family: var(--ibm-font); color: var(--ibm-ink); background: var(--ibm-bg); line-height: 1.55; }
.cb *, .cb *::before, .cb *::after { box-sizing: border-box; }
.cb a { color: var(--ibm-primary); }
.cb a.ibm-button { text-decoration: none; }
.cb a.ibm-button--primary, .cb a.ibm-button--primary:hover { color: #fff; }
.cb a.ibm-tile { color: var(--ibm-ink); }
.cb h1, .cb h2, .cb h3 { color: var(--ibm-dark); letter-spacing: -0.015em; }
.cb-wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.cb-narrow { max-width: 780px; }
.cb-main { padding: 18px 0 56px; }

.cb-skip { position: absolute; left: -9999px; top: auto; }
.cb-skip:focus { position: fixed; left: 8px; top: 8px; z-index: 99999; padding: 10px 16px; background: var(--ibm-dark); color: #fff; border-radius: 6px; font-weight: 700; }

/* Page head */
.cb-head { padding: 26px 0 8px; }
.cb-eyebrow { display: block; font-size: var(--ibm-text-xs); font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--ibm-primary); margin: 10px 0 8px; }
.cb-head h1 { font-size: clamp(1.7rem, 3.4vw, 2.4rem); line-height: 1.12; margin: 0 0 10px; text-wrap: balance; }
.cb-lede { font-size: 1.05rem; color: var(--ibm-ink-2); margin: 0 0 14px; max-width: 46em; }
.cb-facts { display: flex; flex-wrap: wrap; gap: 8px; margin: 6px 0 4px; padding: 0; list-style: none; }
.cb-facts li { font-size: var(--ibm-text-sm); color: var(--ibm-ink-2); background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-radius: var(--ibm-r-pill); padding: 5px 12px; }
.cb-facts b { color: var(--ibm-dark); }

/* In-page section nav */
.cb-tabs { position: sticky; top: 0; z-index: 20; background: var(--ibm-bg); border-bottom: 1px solid var(--ibm-line); margin: 14px 0 22px; }
.cb-tabs ul { display: flex; gap: 4px; list-style: none; margin: 0; padding: 0; overflow-x: auto; scrollbar-width: none; }
.cb-tabs ul::-webkit-scrollbar { display: none; }
.cb-tabs a { display: inline-block; padding: 12px 12px 11px; font-weight: 700; font-size: var(--ibm-text-sm); color: var(--ibm-ink-2); text-decoration: none; border-bottom: 2px solid transparent; white-space: nowrap; }
.cb-tabs a:hover, .cb-tabs a[aria-current="true"], .cb-tabs a[aria-current="page"] { color: var(--ibm-primary); border-bottom-color: var(--ibm-primary); }

.cb-section { margin: 0 0 36px; scroll-margin-top: 64px; }
.cb-section > h2 { font-size: 1.35rem; margin: 0 0 6px; }
.cb-section > .cb-sub { color: var(--ibm-ink-2); margin: 0 0 16px; }

/* Revision notes (content HTML from the chapter file) */
.cb-notes { background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-radius: var(--ibm-r-card); padding: 8px 26px 20px; box-shadow: var(--ibm-shadow); overflow-wrap: anywhere; }
.cb-notes h2 { font-size: 1.2rem; margin: 18px 0 8px; }
.cb-notes h3 { font-size: 1.05rem; margin: 18px 0 6px; }
.cb-notes li { margin: 4px 0; }
.cb-notes table { border-collapse: collapse; display: block; overflow-x: auto; max-width: 100%; }
.cb-notes td, .cb-notes th { border: 1px solid var(--ibm-line); padding: 6px 10px; }
.cb-notes mjx-container[display="true"] { overflow-x: auto; overflow-y: hidden; max-width: 100%; }

/* Route steps */
.cb-steps { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.cb-step { position: relative; background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-radius: var(--ibm-r-card); padding: 18px 18px 16px; display: flex; flex-direction: column; gap: 8px; scroll-margin-top: 70px; }
.cb-step__n { font-size: var(--ibm-text-xs); font-weight: 800; letter-spacing: .08em; text-transform: uppercase; color: var(--ibm-muted); }
.cb-step h3, .cb-step .cb-step-h { margin: 0; font-size: 1.08rem; }
.cb-step p { margin: 0; color: var(--ibm-ink-2); font-size: .94rem; }
.cb-step__meta { font-size: var(--ibm-text-xs); color: var(--ibm-muted); }
.cb-step__actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: auto; padding-top: 6px; }
.cb-step__status { position: absolute; top: 14px; right: 14px; }
.cb-step.is-passed { border-color: var(--ibm-green); box-shadow: inset 0 0 0 1px var(--ibm-green); }

/* Status pill */
.cb-pill { display: inline-flex; align-items: center; gap: 5px; font-size: .72rem; font-weight: 800; border-radius: var(--ibm-r-pill); padding: 3px 9px; background: var(--ibm-surface-2); color: var(--ibm-muted); white-space: nowrap; }
.cb-pill--pass { background: var(--ibm-green-soft); color: var(--ibm-green); }
.cb-pill--try { background: var(--ibm-amber-soft); color: var(--ibm-amber); }
.cb-pill--live { background: var(--ibm-primary-soft); color: var(--ibm-primary); }

/* Practice list */
.cb-filters { display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 14px; }
.cb-list { display: grid; grid-template-columns: minmax(0, 1fr); gap: 16px; }
.cb-list > *, .cb-class > * { min-width: 0; }
.cb .card-prompt, .cb .cb-scheme, .cb .cb-opt { overflow-x: auto; }
.cb-card-foot { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-top: 10px; }
.cb-opts { display: grid; gap: 8px; margin: 4px 0 12px; padding: 0; list-style: none; }
.cb-opt { display: flex; gap: 10px; align-items: flex-start; width: 100%; text-align: left; padding: 10px 12px; min-height: 44px; border: 1px solid var(--ibm-line-strong); border-radius: var(--ibm-r); background: var(--ibm-surface); font: inherit; color: var(--ibm-ink); cursor: pointer; overflow-wrap: anywhere; }
.cb-opt:hover { border-color: var(--ibm-primary); }
.cb-opt:focus-visible { outline: none; box-shadow: var(--ibm-focus); }
.cb-opt__l { flex: none; font-weight: 800; color: var(--ibm-primary); }
.cb-opt[aria-pressed="true"] { border-color: var(--ibm-primary); background: var(--ibm-primary-soft); }
.cb-opt.is-right { border-color: var(--ibm-green); background: var(--ibm-green-soft); }
.cb-opt.is-wrong { border-color: var(--ibm-red); background: var(--ibm-red-soft); }
.cb-opt:disabled { cursor: default; }
.cb-scheme { margin-top: 12px; border: 1px solid var(--ibm-line); border-top: 3px solid var(--ibm-primary); border-radius: var(--ibm-r); background: #fbfcfe; padding: 10px 14px; overflow-wrap: anywhere; }
.cb-scheme[hidden] { display: none; }
.cb-scheme__h { font-weight: 800; color: var(--ibm-dark); font-size: var(--ibm-text-sm); margin: 0 0 6px; }
.cb-selfmark { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-top: 10px; padding: 10px 12px; background: var(--ibm-surface-2); border-radius: var(--ibm-r); font-size: var(--ibm-text-sm); }
.cb-selfmark input { width: 64px; min-height: 36px; padding: 6px 8px; border: 1px solid var(--ibm-line-strong); border-radius: var(--ibm-r); font: inherit; text-align: center; }
.cb-feedback { font-weight: 700; font-size: var(--ibm-text-sm); }
.cb-feedback.ok { color: var(--ibm-green); } .cb-feedback.no { color: var(--ibm-red); }
.cb-lock { background: var(--ibm-surface); border: 1px dashed var(--ibm-line-strong); border-radius: var(--ibm-r-card); padding: 18px 20px; }
.cb-lock h3, .cb-lock .cb-lock-h { margin: 0 0 6px; font-size: 1.05rem; }
.cb-lock p { margin: 0 0 12px; color: var(--ibm-ink-2); }
.cb-muted { color: var(--ibm-muted); font-size: var(--ibm-text-sm); }
.cb-empty { color: var(--ibm-muted); padding: 14px 2px; }

/* Checkpoint */
.cb-check { background: var(--ibm-surface); border: 2px solid var(--ibm-primary); border-radius: 14px; padding: 18px 20px; margin: 18px 0 0; }
.cb-check[hidden] { display: none; }
.cb-check__head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 14px; margin: 0 0 12px; }
.cb-check__head h3 { margin: 0; font-size: 1.15rem; }
.cb-timer { font-variant-numeric: tabular-nums; font-weight: 800; color: var(--ibm-dark); }
.cb-result { border-radius: var(--ibm-r-card); padding: 16px 18px; margin-top: 14px; }
.cb-result.pass { background: var(--ibm-green-soft); }
.cb-result.fail { background: var(--ibm-amber-soft); }
.cb-result h4 { margin: 0 0 4px; font-size: 1.1rem; color: var(--ibm-dark); }
.cb-result p { margin: 0 0 8px; }

/* Mark losses */
.cb-losses { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.cb-losses li { background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-left: 3px solid var(--ibm-amber); border-radius: var(--ibm-r); padding: 10px 14px; }

/* Hub: chapter grid + weightage */
.cb-chapters { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 14px; }
.cb-ch { display: flex; flex-direction: column; gap: 4px; background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-radius: var(--ibm-r-card); padding: 16px 18px; text-decoration: none; color: var(--ibm-ink); min-width: 0; }
a.cb-ch:hover { border-color: var(--ibm-primary); box-shadow: var(--ibm-shadow-lift); }
.cb-ch__n { font-size: var(--ibm-text-xs); font-weight: 800; letter-spacing: .06em; text-transform: uppercase; color: var(--ibm-muted); }
.cb-ch__t { font-weight: 800; color: var(--ibm-dark); font-size: 1.02rem; line-height: 1.3; }
.cb-ch__m { font-size: var(--ibm-text-sm); color: var(--ibm-ink-2); }
.cb-ch--soon { background: var(--ibm-surface-2); border-style: dashed; }
.cb-ch--soon .cb-ch__t { color: var(--ibm-ink-2); }
.cb-ch__bar { margin-top: 8px; }
.cb-table { width: 100%; border-collapse: collapse; background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-radius: var(--ibm-r-card); overflow: hidden; font-size: var(--ibm-text-sm); }
.cb-table th, .cb-table td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--ibm-line); vertical-align: top; }
.cb-table th { background: var(--ibm-surface-2); color: var(--ibm-dark); font-weight: 800; }
.cb-table tr:last-child td { border-bottom: 0; }
.cb-table-wrap { overflow-x: auto; max-width: 100%; }
.cb-cta { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 12px 0 0; }
.cb-cta > .ibm-button, .cb-step__actions > .ibm-button { max-width: 100%; white-space: normal; text-align: center; }
.cb-callout { background: var(--ibm-primary-soft); border-radius: var(--ibm-r-card); padding: 16px 18px; margin: 0 0 20px; }
.cb-callout h3, .cb-callout .cb-callout-h { margin: 0 0 4px; font-size: 1.05rem; }
.cb-callout p { margin: 0; }
.cb-two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }

/* Route progress grid (route page + teacher class view) */
.cb-grid { border-collapse: collapse; font-size: var(--ibm-text-sm); background: var(--ibm-surface); min-width: 100%; }
.cb-grid th, .cb-grid td { border: 1px solid var(--ibm-line); padding: 6px 8px; text-align: center; white-space: nowrap; }
.cb-grid th:first-child, .cb-grid td:first-child { text-align: left; position: sticky; left: 0; background: var(--ibm-surface); z-index: 1; max-width: 220px; overflow: hidden; text-overflow: ellipsis; }
.cb-cell { display: inline-block; min-width: 38px; border-radius: 6px; padding: 2px 6px; font-weight: 800; font-size: .74rem; }
.cb-cell--0 { background: var(--ibm-surface-2); color: var(--ibm-muted); }
.cb-cell--try { background: var(--ibm-amber-soft); color: var(--ibm-amber); }
.cb-cell--1, .cb-cell--2 { background: var(--ibm-diff-medium-soft); color: var(--ibm-diff-medium); }
.cb-cell--3 { background: var(--ibm-green-soft); color: var(--ibm-green); }
.cb-cell--4 { background: var(--ibm-green); color: #fff; }
.cb-legend { display: flex; flex-wrap: wrap; gap: 8px 14px; margin: 10px 0 0; font-size: var(--ibm-text-xs); color: var(--ibm-muted); }

/* Forms (teacher tools, join) */
.cb-form { display: grid; gap: 12px; }
.cb-form label { display: grid; gap: 4px; font-weight: 700; font-size: var(--ibm-text-sm); color: var(--ibm-dark); }
.cb-form input, .cb-form select, .cb-form textarea { min-height: 42px; padding: 9px 12px; border: 1px solid var(--ibm-line-strong); border-radius: var(--ibm-r); font: inherit; font-weight: 400; background: #fff; color: var(--ibm-ink); width: 100%; min-width: 0; }
.cb-form input:focus, .cb-form select:focus { outline: none; border-color: var(--ibm-primary); box-shadow: var(--ibm-focus); }
.cb-form-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.cb-status { min-height: 1.3em; font-weight: 600; font-size: var(--ibm-text-sm); }
.cb-status.ok { color: var(--ibm-green); } .cb-status.err { color: var(--ibm-red); }
.cb-class { display: grid; grid-template-columns: minmax(0, 1fr); gap: 6px; }
.cb-code { font: 800 1.05rem/1 ui-monospace, Menlo, monospace; letter-spacing: .06em; color: var(--ibm-dark); background: var(--ibm-primary-soft); padding: 4px 8px; border-radius: 6px; }
.cb-pick { display: flex; gap: 10px; align-items: flex-start; padding: 10px 12px; border: 1px solid var(--ibm-line); border-radius: var(--ibm-r); background: #fff; overflow-wrap: anywhere; }
.cb-form .cb-pick { display: flex; font-weight: 400; color: var(--ibm-ink); font-size: var(--ibm-text-md); }
.cb-pick input, .cb-form .cb-pick input { width: 18px; min-height: 0; height: 18px; padding: 0; margin-top: 3px; flex: none; accent-color: var(--ibm-primary); }
.cb-pick__meta { font-size: var(--ibm-text-xs); color: var(--ibm-muted); margin-bottom: 4px; }
.cb-picklist { display: grid; gap: 8px; max-height: 520px; overflow: auto; padding: 2px; }
/* Chapter tests (assessments.html) */
.cb-tests { display: grid; gap: 8px; margin-top: 14px; }
.cb-test { display: flex; flex-wrap: wrap; gap: 10px 16px; align-items: center; justify-content: space-between; padding: 12px 14px; border: 1px solid var(--ibm-line); border-radius: var(--ibm-r); background: var(--ibm-surface); }
.cb-test__name { display: grid; gap: 2px; min-width: 0; flex: 1 1 260px; }
.cb-test__act { display: flex; flex-wrap: wrap; gap: 8px; }

/* Info pages */
.cb-prose { background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-radius: var(--ibm-r-card); padding: 10px 26px 22px; }
.cb-prose h2 { font-size: 1.2rem; margin: 22px 0 8px; }
.cb-prose p, .cb-prose li { color: var(--ibm-ink-2); }

@media (max-width: 760px) {
  .cb-steps, .cb-two, .cb-form-row { grid-template-columns: 1fr; }
  .cb-notes, .cb-prose { padding: 4px 16px 16px; }
  .cb-wrap { padding: 0 16px; }
}
/* NCERT solutions (build-cbse-pages.js → solutionsPage) */
.cb-solcard { background: var(--ibm-surface); border: 1px solid var(--ibm-line); border-radius: var(--ibm-r-card); padding: 16px 18px; margin: 0 0 14px; overflow-wrap: anywhere; scroll-margin-top: 64px; }
.cb-solcard h3 { font-size: 1.02rem; margin: 0 0 6px; }
.cb-solcard__intro { margin: 0 0 8px; color: var(--ibm-ink-2); }
.cb-solq { padding: 10px 0; border-top: 1px dashed var(--ibm-line); scroll-margin-top: 64px; }
.cb-solq:first-of-type { border-top: 0; }
.cb-solq__s { margin: 0 0 6px; }
.cb-solq__s .cb-table-wrap, .cb-solcard__intro .cb-table-wrap { display: block; margin: 8px 0; }
.cb-table.cb-freq { width: auto; min-width: 220px; }
.cb-sol > summary { cursor: pointer; font-weight: 700; font-size: var(--ibm-text-sm); color: var(--ibm-primary); padding: 4px 0; width: max-content; }
.cb-sol[open] > summary { margin-bottom: 4px; }
.cb-sol__steps { margin: 4px 0 8px; padding-left: 1.3em; }
.cb-sol__steps li { margin: 5px 0; }
.cb-sol__ans { margin: 6px 0 0; padding: 8px 12px; background: var(--ibm-green-soft); border-radius: var(--ibm-r); }
.cb-sol__tip { margin: 8px 0 0; padding: 8px 12px; background: var(--ibm-amber-soft); border-radius: var(--ibm-r); font-size: .94rem; }
.cb-solcard__more { margin: 8px 0 0; font-size: var(--ibm-text-sm); font-weight: 700; }
.cb-solcard mjx-container[display="true"], .cb-solq mjx-container { max-width: 100%; overflow-x: auto; overflow-y: hidden; }

@media print {
  nav.topnav, footer, .cb-tabs, .cb-noprint { display: none !important; }
  body.cb { background: #fff; }
}