/* Scoped reading layout for Chapter 0; site theme controls the palette. */
.bridge-notes-page,
.stats-bridge {
  --bridge-accent: #087f80;
  --bridge-accent-soft: #eaf7f4;
  --bridge-violet: #6954a3;
  --bridge-violet-soft: #f3effb;
  --bridge-warning: #8a5520;
  --bridge-warning-soft: #fff6e2;
  --bridge-coral: #ad4835;
  --bridge-coral-soft: #fff1ed;
  color: var(--m4u-text);
}
[data-theme="dark"] .bridge-notes-page,
[data-theme="dark"] .stats-bridge {
  --bridge-accent: #71d5cb;
  --bridge-accent-soft: #173431;
  --bridge-violet: #c1adf7;
  --bridge-violet-soft: #2c2542;
  --bridge-warning: #f1ce88;
  --bridge-warning-soft: #352e20;
  --bridge-coral: #ffab98;
  --bridge-coral-soft: #382725;
}
.bridge-notes-page { max-width: 1040px; }
.bridge-page-heading { padding: 1.4rem 0 1.7rem; background: transparent; color: var(--m4u-text); text-align: left; }
.bridge-page-heading .bridge-kicker { color: var(--bridge-accent); font-size: .78rem; font-weight: 750; letter-spacing: .09em; text-transform: uppercase; }
.bridge-page-heading h1 { font-size: clamp(2rem,4vw,3.1rem); line-height: 1.15; letter-spacing: -.035em; max-width: 920px; margin: .7rem 0 1.3rem; }
.bridge-page-actions { display: flex; flex-wrap: wrap; align-items: center; gap: .7rem; }
.bridge-page-actions .btn { padding: .65rem 1rem; }
.bridge-reader-card { border-radius: 1rem; overflow: hidden; }
.bridge-reader-card > .card-header { display: none; }
.bridge-reader-card > .card-body { padding: clamp(1.15rem,4vw,3.2rem); }
.stats-bridge { max-width: 840px; margin-inline: auto; font-size: 1.075rem; line-height: 1.8; overflow-wrap: break-word; }
.stats-bridge p { margin: 0 0 1.15rem; }
.stats-bridge h2 { color: var(--m4u-text); font-size: 1.6rem; line-height: 1.35; font-weight: 720; letter-spacing: -.025em; margin: 3rem 0 1.2rem; }
.stats-bridge h3 { color: var(--m4u-text); font-size: 1.1rem; font-weight: 700; line-height: 1.45; margin: 0 0 .7rem; }
.stats-bridge li { padding-left: .15rem; margin: .4rem 0; }
.stats-bridge a { text-underline-offset: .2em; }
.stats-bridge :focus-visible { outline: 3px solid var(--m4u-primary); outline-offset: 4px; }
.stats-bridge .bridge-lead { color: var(--m4u-muted); font-size: 1.17rem; line-height: 1.7; }
.bridge-meta { display: flex; gap: .7rem 1.5rem; flex-wrap: wrap; color: var(--m4u-muted); font-size: .8rem; border-bottom: 1px solid var(--m4u-border); padding: .2rem 0 1.5rem; margin-bottom: 1.8rem; }
.bridge-goals { background: var(--bridge-accent-soft); border-left: 4px solid var(--bridge-accent); padding: 1.4rem 1.6rem; border-radius: 0 .65rem .65rem 0; }
.stats-bridge .bridge-goals h2 { color: var(--bridge-accent); margin: 0 0 .65rem; font-size: 1rem; letter-spacing: 0; }
.bridge-goals ul { margin: 0; padding-left: 1.2rem; font-size: .96rem; }
.stats-bridge .bridge-prerequisites { color: var(--m4u-muted); font-size: .9rem; margin: 1.3rem 0; }
.bridge-outline { display: flex; gap: .5rem; flex-wrap: wrap; margin: 1.5rem 0 2.5rem; }
.bridge-outline a { background: var(--m4u-surface-2); border: 1px solid var(--m4u-border); color: var(--m4u-muted); border-radius: .5rem; padding: .5rem .75rem; font-size: .79rem; line-height: 1.45; text-decoration: none; }
.bridge-outline a:hover { color: var(--bridge-accent); border-color: var(--bridge-accent); }
.bridge-section { scroll-margin-top: 1.5rem; }
.stats-bridge .bridge-label { color: var(--bridge-accent); font-size: .7rem; font-weight: 800; line-height: 1.5; text-transform: uppercase; letter-spacing: .1em; margin: 0 0 .55rem; }
.bridge-formula { background: var(--bridge-accent-soft); border: 1px solid var(--m4u-border); border-radius: .75rem; margin: 1.7rem 0; padding: 1.3rem 1.5rem; }
.stats-bridge .bridge-formula h3 { color: var(--m4u-text); }
.stats-bridge .bridge-formula-note { color: var(--m4u-muted); font-size: .88rem; line-height: 1.7; margin: .7rem 0 0; }
.bridge-math { overflow-x: auto; overflow-y: hidden; max-width: 100%; padding: .45rem .1rem; }
.bridge-math mjx-container[display="true"] { margin: .65rem 0 !important; }
.stats-bridge mjx-container { color: inherit; }
.stats-bridge .bridge-example { border: 1px solid var(--m4u-border); border-radius: .8rem; margin: 2rem 0; overflow: hidden; background: var(--m4u-surface); }
.bridge-example-head { background: var(--bridge-violet-soft); padding: 1.35rem 1.5rem; border-bottom: 1px solid var(--m4u-border); }
.bridge-example-head .bridge-label { color: var(--bridge-violet); }
.stats-bridge .bridge-example-head p:last-child { margin-bottom: 0; }
.bridge-example-body { padding: 1.5rem; }
.stats-bridge .bridge-steps { list-style: none; margin: 0; padding: 0; counter-reset: bridge-step; }
.bridge-steps > li { position: relative; counter-increment: bridge-step; padding: 0 0 0 2.1rem; margin: 0 0 1.4rem; }
.bridge-steps > li::before { content: counter(bridge-step); position: absolute; left: 0; top: .15rem; width: 1.5rem; height: 1.5rem; display: grid; place-items: center; background: var(--m4u-surface-2); color: var(--m4u-muted); border: 1px solid var(--m4u-border); font-size: .72rem; font-weight: 750; border-radius: 50%; }
.bridge-steps p { font-size: .97rem; margin-bottom: .5rem; }
.bridge-answer { border-left: 3px solid var(--bridge-accent); background: var(--bridge-accent-soft); padding: 1rem 1.1rem; border-radius: 0 .5rem .5rem 0; font-size: .96rem; line-height: 1.75; }
.bridge-answer strong { color: var(--bridge-accent); }
.bridge-note { border-left: 3px solid var(--bridge-warning); background: var(--bridge-warning-soft); border-radius: 0 .65rem .65rem 0; padding: 1.2rem 1.4rem; margin: 1.7rem 0; }
.bridge-note .bridge-label { color: var(--bridge-warning); }
.bridge-note.bridge-pitfall { background: var(--bridge-coral-soft); border-color: var(--bridge-coral); }
.bridge-note.bridge-pitfall .bridge-label { color: var(--bridge-coral); }
.bridge-note p:last-child { margin: 0; font-size: .96rem; }
.bridge-figure { background: var(--m4u-surface); border: 1px solid var(--m4u-border); border-radius: .75rem; padding: 1.15rem; margin: 1.8rem 0; }
.bridge-figure img { display: block; width: 100%; height: auto; }
.bridge-figure .bridge-diagram-dark { display: none; }
[data-theme="dark"] .bridge-figure .bridge-diagram-light { display: none; }
[data-theme="dark"] .bridge-figure .bridge-diagram-dark { display: block; }
.bridge-figure figcaption { color: var(--m4u-muted); font-size: .8rem; line-height: 1.75; padding: .9rem .25rem 0; }
.bridge-table { overflow-x: auto; margin: 1.7rem 0; border: 1px solid var(--m4u-border); border-radius: .65rem; }
.bridge-table table { width: 100%; font-size: .92rem; line-height: 1.65; border-collapse: collapse; }
.bridge-table th,.bridge-table td { padding: .9rem 1rem; border-bottom: 1px solid var(--m4u-border); vertical-align: top; }
.bridge-table th { text-align: left; font-weight: 650; }
.bridge-table thead { background: var(--m4u-surface-2); }
.bridge-table tbody tr:last-child > * { border-bottom: 0; }
.bridge-muted { color: var(--m4u-muted); }
.bridge-practice { border: 1px solid var(--m4u-border); border-radius: .75rem; padding: 1.4rem; margin: 1.3rem 0; background: var(--m4u-surface); }
.bridge-practice details { border-top: 1px solid var(--m4u-border); padding-top: .8rem; }
.bridge-practice summary { color: var(--bridge-accent); font-size: .9rem; font-weight: 700; padding: .4rem 0; cursor: pointer; }
.bridge-solution { padding-top: 1.2rem; }
.bridge-checklist { background: var(--bridge-accent-soft); border-radius: .8rem; padding: 1.5rem; margin: 2.5rem 0; }
.bridge-checklist legend { float: none; width: auto; color: var(--m4u-text); font-size: 1.25rem; font-weight: 700; padding: 0; margin: 0 0 .8rem; }
.bridge-checklist label { display: flex; align-items: flex-start; gap: .8rem; font-size: .95rem; margin: .8rem 0; cursor: pointer; }
.bridge-checklist input { flex: none; accent-color: var(--bridge-accent); width: 1rem; height: 1rem; margin-top: .35rem; }
.bridge-next { display: block; text-decoration: none; color: var(--m4u-text); border: 1px solid var(--m4u-border); background: var(--m4u-surface-2); border-radius: .8rem; padding: 1.5rem; }
.bridge-next:hover { color: var(--m4u-text); border-color: var(--bridge-accent); }
.bridge-next strong { display: block; font-size: 1.25rem; line-height: 1.4; margin: .5rem 0; }
.stats-bridge .bridge-next p { color: var(--m4u-muted); font-size: .9rem; line-height: 1.7; margin: .5rem 0 0; }
.stats-bridge .bridge-sources { background: transparent !important; color: var(--m4u-muted) !important; text-align: left; border-top: 1px solid var(--m4u-border); padding: 1.5rem 0 0; margin: 2.5rem 0 0; font-size: .78rem; }
.stats-bridge .bridge-sources h2 { margin: 0 0 .5rem; font-size: .85rem; color: var(--m4u-muted); letter-spacing: 0; }
.bridge-sources ul { margin: 0 0 1.3rem; padding-left: 1.2rem; }
.bridge-resource-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 1rem; align-items: start; }
.bridge-resource-grid > .card { margin-bottom: 0 !important; }
.bridge-resource-grid > .bridge-resource-wide { grid-column: 1 / -1; order: 3; }
.bridge-resource-grid .ratio { max-width: 960px; margin-inline: auto; }
[data-theme="dark"] .bridge-subchapter-page .btn-outline-primary { color: #9bc7ff; border-color: #6698db; }
[data-theme="dark"] .bridge-subchapter-page .btn-outline-primary:hover,
[data-theme="dark"] .bridge-subchapter-page .btn-outline-primary:focus { color: #fff; background: #2864ae; border-color: #9bc7ff; }
[data-theme="dark"] .bridge-subchapter-page .nav-pills .nav-link:not(.active) { color: #9bc7ff; }
@media (max-width: 600px) {
  .bridge-notes-page { padding-inline: .85rem; }
  .bridge-page-heading h1 { font-size: 2rem; }
  .bridge-reader-card > .card-body { padding: 1.1rem; }
  .stats-bridge { font-size: 1rem; line-height: 1.8; }
  .stats-bridge h2 { font-size: 1.4rem; margin-top: 2.2rem; }
  .bridge-formula,.bridge-goals,.bridge-note,.bridge-example-head,.bridge-example-body,.bridge-practice,.bridge-checklist { padding: 1.1rem; }
  .bridge-figure { padding: .55rem; }
  .bridge-resource-grid { grid-template-columns: 1fr; }
  .bridge-page-actions .btn { flex: 1; }
}
@media print {
  .bridge-page-actions,.bridge-outline,.bridge-next,.bridge-notes-page > a { display: none !important; }
  .bridge-notes-page { max-width: none; padding: 0; }
  .bridge-reader-card { border: 0; box-shadow: none !important; }
  .bridge-reader-card > .card-body { padding: 0; }
  .stats-bridge { max-width: none; font-size: 10.5pt; color: #172b45; }
  .bridge-formula,.bridge-note,.bridge-figure { break-inside: avoid; }
  .bridge-figure .bridge-diagram-light { display: block !important; }
  .bridge-figure .bridge-diagram-dark { display: none !important; }
}