.has-impersonation { padding-bottom:8rem!important; }
.impersonation-banner { position:fixed; inset:auto 0 0; z-index:10000; display:flex; flex-wrap:wrap; align-items:center; justify-content:space-between; gap:.75rem; padding:1rem max(1rem,env(safe-area-inset-left)); background:var(--surface); color:var(--ink); border-top:3px solid var(--green); box-shadow:0 -3px 16px #20292e20; font:600 .875rem/1.5 var(--sans); }
.impersonation-banner a { color:var(--green); padding:.65rem; min-height:44px; border:1px solid var(--control-border); border-radius:var(--lv-control-radius); background:linear-gradient(180deg,#ffffff77,#ffffff00),var(--soft); box-shadow:var(--lv-press-shadow); }
/* Shared adaptive presentation: 55% reading glass, 75% chrome, opaque controls.
 * Containers adapt to the space left by the shell, not a guessed device size.
 */
:root, html[data-theme] {
  --paper: #f4f6f7; --surface: #fff; --ink: #20292e; --muted: #53616a;
  --line: #d4dcdf; --control-border: #9baab1; --green: #126456; --on-green: #fff;
  --soft: #e2eee9; --chip: #eaf0f2;
  --lv-canvas-max: none;
  --lv-rail-width: 12rem;
  --lv-gutter: clamp(1rem, 2vw, 2rem);
  --lv-section-gap: 1.25rem;
  --lv-card-min: 18rem;
  --lv-control-radius: 12px;
  --lv-panel-radius: 8px;
  --lv-reading-width: calc(68 * var(--lv-char));
  --lv-action: #126456;
  --lv-on-action: #fff;
  --lv-material: var(--glass-shell, rgb(255 254 250 / .75));
  --lv-gloss-shadow: 0 8px 28px #14242a12;
  --lv-press-shadow: inset 0 1px 0 #ffffff52, 0 3px 8px #14242a16;
  --sans: -apple-system, BlinkMacSystemFont, "Inter Variable", Inter, "Segoe UI", sans-serif;
}
html { text-size-adjust: 100%; -webkit-text-size-adjust: 100%; }
body.learning-studio, .landing-page, .access-page, .admin-shell, .moodle-page, .potepedia-page {
  font-family: var(--sans); accent-color: var(--lv-action);
}
body.learning-studio, body.learning-studio:has(#panel-exams:not([hidden])) {
  --paper: #f4f6f7; --surface: #fff; --ink: #20292e; --muted: #53616a;
  --line: #d4dcdf; --control-border: #9baab1;
  --studio-sidebar: #eef2f4; --studio-inset: #f0f4f5; --radius: 8px;
  font-size: 1rem; line-height: 1.6;
}
html[data-theme="dark"], html[data-theme="dark"] body.learning-studio,
html[data-theme="dark"] body.learning-studio:has(#panel-exams:not([hidden])) {
  --green: #9bd9bf; --on-green: #16372b; --soft: #2a4536; --chip: #2c4235;
  --paper: #171b1e; --surface: #232a2e; --ink: #f3f6f7; --muted: #bdc8cd;
  --line: #47545c; --control-border: #82949e; --studio-sidebar: #20272b; --studio-inset: #2b3338;
}
@media (prefers-color-scheme: dark) {
  html[data-theme="auto"], html[data-theme="auto"] body.learning-studio,
  html[data-theme="auto"] body.learning-studio:has(#panel-exams:not([hidden])) {
    --green: #9bd9bf; --on-green: #16372b; --soft: #2a4536; --chip: #2c4235;
    --paper: #171b1e; --surface: #232a2e; --ink: #f3f6f7; --muted: #bdc8cd;
    --line: #47545c; --control-border: #82949e; --studio-sidebar: #20272b; --studio-inset: #2b3338;
  }
}
body.learning-studio *, .landing-page *, .access-page *, .admin-shell *,
.moodle-page *, .potepedia-page * { letter-spacing: 0 !important; }
body.learning-studio :is(.site-header, .shell),
body.learning-studio:has(#panel-exams:not([hidden])) :is(.site-header, .shell) {
  width: 100%; max-width: var(--lv-canvas-max); padding-inline: var(--lv-gutter);
}
body.learning-studio #main { min-width: 0; container: workspace / inline-size; }
body.learning-studio [role="tabpanel"] { min-width: 0; container: panel / inline-size; }
body.learning-studio :is(.card, .course-panel, .course-tile, .course-topic-card,
.reader-workspace, .lernkompass, .exams, .lv-finder, .community-dialog),
.landing-page :is(.demo, .login-fields), .access-card, .admin-card {
  min-width: 0; container-type: inline-size;
}
body.learning-studio :is(.card, .course-panel, .section-heading, .home-welcome-copy,
.reader-workspace, .exams, .lernkompass, form) > * { min-width: 0; }

/* Stable, zoom-friendly type; preserve the user's reading font and size. */
body.learning-studio :is(h1, h2, h3, h4, .brand strong, .studio-card-copy strong,
.home-primary-slot .home-focus h2, .home-primary-slot .home-focus h3) {
  font-family: var(--sans); font-weight: 650; line-height: 1.3; overflow-wrap: anywhere;
}
body.learning-studio :is(.section-heading h1, .course-library-heading h1,
.course-banner h1, .home-welcome h1, .lernkompass h1) { font-size: 2rem; line-height: 1.2; }
body.learning-studio #main h1 { font-size: 2rem; }
body.learning-studio #main h2 { font-size: 1.5rem; }
body.learning-studio #main h3 { font-size: 1.125rem; }
body.learning-studio :is(.home-section-heading h2, .course-section-heading h2,
.course-next-step h2, .home-primary-slot .home-focus h2, .home-primary-slot .home-focus h3) { font-size: 1.5rem; }
body.learning-studio :is(.course-tile-heading h3, .studio-card-copy strong,
.course-topic-copy h3, .course-topic-copy h4, .exams .ex-lesson-card h3, .exams .es-topic h3) { font-size: 1.125rem; }
body.learning-studio :is(label, small, .eyebrow, .muted, .notice, .status,
.document-meta, .course-tile-meta, .course-next-reason, .course-pin, .home-small,
.reader-position, .reader-task-context, .finder-result-meta, .finder-result-snippet) { font-size: .875rem; line-height: 1.6; }
body.learning-studio :is(.section-heading p, .home-welcome-line, .course-hook,
.home-primary-slot .home-focus-copy, .course-banner-hook) { font-size: 1rem; line-height: 1.65; max-width: calc(66 * var(--lv-char)); }
body.learning-studio:not([data-active-tab="home"]) #main > [role="tabpanel"] > .section-heading { margin: .5rem 0 1rem; }
body.learning-studio:not([data-active-tab="home"]) #main > [role="tabpanel"] > .section-heading h1 { font-size: 1.625rem; margin-bottom: .5rem; }
body.learning-studio:not([data-active-tab="home"]) #main > [role="tabpanel"] > .section-heading p { margin-block: .25rem; }
body.learning-studio :is(.prose, .prep-prose, .help-reading, .exams .ex-lecture-text,
.exams .ex-lecture-board ul, .exams .ex-lecture-board ol, .lernkompass .lk-prose) {
  max-width: var(--lv-reading-width); line-height: 1.8;
}
body.learning-studio #question-prompt { font-family: var(--reading-font); font-size: 1.25rem; line-height: 1.65; }
body.learning-studio #viewer-content > .reader-text .prose { max-width: calc(68 * var(--lv-char)); font-size: 1.125rem; line-height: 1.8; }
html[data-reading-size="large"] body.learning-studio #viewer-content > .reader-text .prose { font-size: 1.25rem; }
html[data-reading-size="larger"] body.learning-studio #viewer-content > .reader-text .prose { font-size: 1.5rem; }
html[data-reading-width="wide"] body.learning-studio #viewer-content > .reader-text .prose { max-width: calc(84 * var(--lv-char)); }
body.learning-studio .reader-display-fields { grid-template-columns: repeat(auto-fit, minmax(min(100%, 10rem), 1fr)); }

/* Neutral is the default. Primary, selected and destructive actions are explicit. */
body.learning-studio :is(button, .button, .home-primary, .course-primary,
.ex-primary, .prep-primary, .uni-open-platform, .lk-primary, .page-share),
.landing-page :is(button, .button), .access-card button, .admin-shell button,
.moodle-page button, .potepedia-page button {
  min-height: 44px; border-radius: var(--lv-control-radius); font-family: var(--sans);
  font-size: .9375rem; font-weight: 600; line-height: 1.4;
  white-space: normal; overflow-wrap: anywhere; touch-action: manipulation;
}
body.learning-studio button, .admin-shell button, .moodle-page button, .potepedia-page button {
  background: var(--surface); color: var(--ink); border: 1px solid var(--control-border, var(--line)); box-shadow: none;
}
body.learning-studio :is(.button:not(.secondary), .home-primary, .course-primary,
.ex-primary, .prep-primary, .uni-open-platform, .lk-primary, button.primary,
button[type="submit"]:not(.secondary, .quiet, .danger), :where(#submit-answer)),
.landing-page :is(.button, .login-card button[type="submit"], .answer-row button),
.access-card button[type="submit"], .admin-shell button[type="submit"], .admin-shell button.primary {
  display: inline-flex; align-items: center; justify-content: center; gap: .65rem;
  min-height: 48px; padding: .7rem 1.15rem;
  background: linear-gradient(180deg, #ffffff0d, transparent 60%), var(--lv-action);
  color: var(--lv-on-action); border: 1px solid #367e72;
  box-shadow: var(--lv-press-shadow); text-decoration: none;
}
body.learning-studio :is(button.secondary, .secondary, .menu-toggle, .page-share) {
  background: var(--surface); color: var(--ink); border-color: var(--line); box-shadow: none;
}
body.learning-studio :is(button.quiet, .quiet) { color: var(--green); background: transparent; border-color: transparent; box-shadow: none; }
body.learning-studio :is(button[aria-pressed="true"], .course-view-switch button[aria-pressed="true"]),
.landing-page :is(.subject-tabs button[aria-pressed="true"], .day-list button[aria-pressed="true"]) {
  background: var(--soft); color: var(--ink); border-color: var(--green); box-shadow: inset 0 0 0 1px var(--green);
}
body.learning-studio button.danger, .admin-shell button.danger {
  color: var(--red, #a23232); border-color: currentColor; background: var(--surface); box-shadow: none;
}
body.learning-studio :is(button:disabled, [aria-disabled="true"]),
.landing-page button:disabled, .access-card button:disabled, .admin-shell button:disabled {
  opacity: .65; cursor: not-allowed; transform: none; box-shadow: none;
}
body.learning-studio [aria-busy="true"], .landing-page [aria-busy="true"] { cursor: progress; }
body.learning-studio :is(input:not([type="checkbox"]):not([type="radio"]):not([type="range"]), select, textarea),
.landing-page :is(input, select), .access-card :is(input, select),
.admin-shell :is(input:not([type="checkbox"]):not([type="radio"]), select, textarea),
.moodle-page :is(input, select), .potepedia-page :is(input, select) {
  min-width: 0; max-width: 100%; min-height: 48px; border-radius: var(--lv-control-radius);
  background: var(--surface, #fff); color: var(--ink); border: 1px solid var(--control-border, #9baab1);
  font-family: var(--sans); font-size: 1rem; font-weight: 400; line-height: 1.5; padding: .65rem .8rem; box-shadow: none;
}
body.learning-studio textarea, .admin-shell textarea { resize: vertical; }
body.learning-studio :is(input[type="checkbox"], input[type="radio"]),
.admin-shell :is(input[type="checkbox"], input[type="radio"]) { width: 1.125rem; height: 1.125rem; min-height: 0; flex: 0 0 auto; }
body.learning-studio label:has(> input[type="checkbox"]),
body.learning-studio label:has(> input[type="radio"]) { min-height: 44px; align-items: center; }
body.learning-studio :is(button, a, input, select, textarea, summary):focus-visible,
.landing-page :is(button, a, input, select, summary):focus-visible,
.access-page :is(button, a, input, select):focus-visible { outline: 3px solid var(--green); outline-offset: 3px; }

/* Sections are unframed; repeated items and reading tools have subtle borders. */
body.learning-studio :is(.card, .course-panel, .prep-content, .prep-inbox,
.prep-builder, .prep-review, .prep-generation, .prep-versions, .prep-packages) {
  border-radius: 0; border-inline: 0; border-bottom: 0; border-top: 1px solid var(--line);
  padding: 1.25rem 0; background: transparent; box-shadow: none;
}
body.learning-studio :is(.course-tile, .course-topic-card, .family-card, .topic-card,
.home-link-card, .home-day-card, .home-review-card, .exams .eb-card) {
  border: 1px solid var(--line); border-radius: var(--lv-panel-radius);
  background: var(--glass-reading, var(--surface)); color: var(--ink);
}
body.learning-studio .home-primary-slot .home-focus, body.learning-studio .course-next-step {
  background: transparent; border: 0; border-left: 3px solid var(--green);
  border-radius: 0; padding: .25rem 0 .25rem 1.25rem; box-shadow: none;
}
body.learning-studio .home-primary-slot .home-primary { width: auto; }
body.learning-studio :is(.question-card, .viewer-card, .reader-task-preview,
.exams .ex-question, .exams .ex-practice-question, .exams .ex-check,
.exams .ex-lecture-board, .qs-section, .qs-panel, #tutor-response,
#tutor-thread, #source-viewer, .prep-attempt, .prep-practice-panel) {
  background: var(--glass-reading, var(--surface)); border-radius: 8px; padding: 1.25rem;
  box-shadow: inset 0 1px 0 var(--glass-highlight, transparent), var(--glass-shadow, none);
}
body.learning-studio :is(.home-study-grid, .home-link-grid, .home-contact-grid,
.course-mosaic:not(.course-list), .course-topic-grid, #family-grid, #topic-grid,
.exams .ex-lesson-grid, .exams .ex-practice-grid, .exams .ex-form-grid, .exams .eb-grid,
.prep-form-cards, .badge-wall, .source-grid, .lk-choices) {
  grid-template-columns: repeat(auto-fit, minmax(min(100%, var(--lv-card-min)), 1fr)); gap: 1rem;
}
body.learning-studio :is(.home-link-grid, .home-contact-grid) { --lv-card-min: 15rem; }
body.learning-studio :is(.course-tile-copy, .course-topic-copy) { padding: 1rem; }
body.learning-studio .course-view-switch { display: inline-flex; padding: .2rem; gap: .2rem; border: 1px solid var(--line); border-radius: 12px; }
body.learning-studio .course-view-switch button { min-width: 44px; }

/* One selected state across the existing rail and dock; routing is unchanged. */
body.learning-studio .tabs, body.learning-studio:has(#panel-exams:not([hidden])) .tabs {
  background: var(--lv-material); border: 1px solid var(--line); box-shadow: var(--lv-gloss-shadow);
}
body.learning-studio .tabs button, body.learning-studio:has(#panel-exams:not([hidden])) .tabs button {
  color: var(--muted); background: transparent; border: 1px solid transparent;
  box-shadow: none; transform: none; font-size: .9375rem;
}
body.learning-studio .tabs button[aria-selected="true"],
body.learning-studio .tabs button.is-current-section,
body.learning-studio:has(#panel-exams:not([hidden])) .tabs button[aria-selected="true"] {
  color: var(--ink); background: var(--surface); border-color: var(--line);
  box-shadow: 0 2px 6px #14242a0c; font-weight: 700;
}
body.learning-studio .tabs button[aria-selected="true"] .nav-icon { color: var(--green); }
body.learning-studio .studio-nav-note { display: none; }
body.learning-studio .studio-nav-brand { padding-bottom: 1rem; }
body.learning-studio .studio-nav-brand strong { font-family: var(--sans); font-size: 1.75rem; font-weight: 700; }
body.learning-studio .header-actions { flex-wrap: wrap; gap: .5rem; }
body.learning-studio .header-actions button { min-height: 44px; }
body.learning-studio .header-actions .adaptive-tool { position: relative; display: inline-flex; align-items: center; justify-content: center; gap: .5rem; }
body.learning-studio .header-actions .adaptive-tool .tool-glyph { display: none; }
body.learning-studio .header-actions .tool-icon {
  position: relative; display: inline-flex; align-items: center; justify-content: center;
  width: 44px; min-width: 44px; height: 44px; padding: 0; flex: 0 0 44px; border-radius: 50%;
}
.tool-glyph { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.tool-label { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
body.learning-studio .header-actions .page-share > span { display: none; }
body.learning-studio [data-tooltip]::after {
  content: attr(data-tooltip); position: absolute; top: calc(100% + .5rem); right: 0;
  z-index: 30; width: max-content; max-width: min(16rem, calc(100vw - 2rem)); padding: .35rem .6rem;
  box-sizing: border-box; white-space: normal; overflow-wrap: anywhere;
  border-radius: 6px; background: var(--ink); color: var(--surface);
  font-size: .875rem; line-height: 1.4; pointer-events: none; display: none;
}
body.learning-studio [data-tooltip]:is(:hover, :focus-visible)::after { display: block; }
@media (min-width: 1100px) {
  body.learning-studio .shell, body.learning-studio:has(#panel-exams:not([hidden])) .shell {
    display: grid; grid-template-columns: var(--lv-rail-width) minmax(0, 1fr); gap: var(--lv-gutter);
  }
  body.learning-studio .tabs, body.learning-studio:has(#panel-exams:not([hidden])) .tabs {
    border-radius: 16px; padding: .75rem .5rem; min-height: 0; max-height: calc(100dvh - 2rem); overflow-y: auto;
  }
}
@media (max-width: 1099px) {
  body.learning-studio .tabs button, body.learning-studio:has(#panel-exams:not([hidden])) .tabs button { min-width: 44px; min-height: 56px; font-size: .8125rem; }
  body.learning-studio .tabs { overflow: visible; }
  body.learning-studio .tabs .primary-tabs { min-width: 0; flex: 4 1 auto; overflow-x: auto; }
  body.learning-studio .tabs button.tab-primary { flex: 1 0 auto; white-space: nowrap; overflow-wrap: normal; }
  body.learning-studio .tabs #dock-more { flex: 1 0 auto; }
}
@media (max-width: 600px) {
  body.learning-studio .header-actions { width: 100%; gap: .25rem; justify-content: space-between; }
  body.learning-studio:not([data-active-tab="home"]) .site-header { padding-block: calc(.5rem + env(safe-area-inset-top)) .5rem; gap: .5rem; }
  body.learning-studio:not([data-active-tab="home"]) .brand > div > span { display: none; }
  body.learning-studio .header-actions :is(.adaptive-tool, .menu-toggle) {
    display: inline-flex; align-items: center; justify-content: center;
    width: 44px; height: 44px; padding: 0; flex: 0 0 44px; border-radius: 50%;
  }
  body.learning-studio .header-actions .adaptive-tool .tool-glyph { display: block; }
  body.learning-studio .header-actions .adaptive-tool-label,
  body.learning-studio .header-actions .menu-toggle > span:last-child {
    position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
    overflow: hidden; clip-path: inset(50%); white-space: nowrap;
  }
  body.learning-studio #community-toggle::after { left: 0; right: auto; }
}
@container workspace (min-width: 62rem) {
  body.learning-studio #panel-tutor {
    display: grid; grid-template-columns: minmax(18rem, .75fr) minmax(0, 1.25fr); gap: var(--lv-section-gap); align-items: start;
  }
  body.learning-studio #panel-tutor > :is(.section-heading, #tutor-availability, [id^="return-"], #resume-tutor, #clear-tutor) { grid-column: 1 / -1; }
  body.learning-studio #tutor-form { grid-column: 1; grid-row: span 2; position: sticky; top: 1rem; }
  body.learning-studio :is(#tutor-thread, #tutor-response) { grid-column: 2; }
  body.learning-studio #panel-sources:not(.source-reading) {
    display: grid; grid-template-columns: minmax(17rem, .28fr) minmax(0, 1fr); gap: var(--lv-section-gap); align-items: start;
  }
  body.learning-studio #panel-sources > :is(.section-heading, #source-inventory) { grid-column: 1 / -1; }
  body.learning-studio #source-form { grid-column: 1; grid-row: span 3; position: sticky; top: 1rem; }
  body.learning-studio #panel-sources > :is(#source-results, #source-documents, h2) { grid-column: 2; }
  body.learning-studio #panel-sources.source-reading { display: block; }
  body.learning-studio #panel-plan {
    display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--lv-section-gap); align-items: start;
  }
  body.learning-studio #panel-plan > :is(.section-heading, .workspace-nav, #workspace-status) { grid-column: 1 / -1; }
  body.learning-studio #workspace-week {
    display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(19rem, .6fr); gap: var(--lv-section-gap); align-items: start;
  }
  body.learning-studio #workspace-week > .study-shortcuts { grid-column: 1 / -1; }
  body.learning-studio #workspace-week > section:nth-of-type(1) { grid-column: 1; grid-row: 2 / 4; }
  body.learning-studio #workspace-week > section:nth-of-type(2) { grid-column: 2; grid-row: 2; }
  body.learning-studio #workspace-week > section:nth-of-type(3) { grid-column: 2; grid-row: 3; }
  body.learning-studio #workspace-week > section:nth-of-type(4) { grid-column: 1 / -1; }
  body.learning-studio #panel-plan > :is(#workspace-calendar, #workspace-tasks, #workspace-notes, #workspace-board) { grid-column: 1 / -1; }
  body.learning-studio #panel-me {
    display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem 1.5rem; align-items: start;
  }
  body.learning-studio #panel-me > .section-heading { grid-column: 1 / -1; }
  body.learning-studio #panel-me > .profile-identity { grid-column: 1 / -1; }
  body.learning-studio #panel-me > .profile-editor { grid-column: 1; }
  body.learning-studio #panel-me > .profile-accounts { grid-column: 2; }
  body.learning-studio #panel-me > .profile-disclosure { grid-column: 1 / -1; }
  body.learning-studio #panel-me > .profile-academics { grid-column: 1 / -1; }
  body.learning-studio #panel-karten {
    display: grid; grid-template-columns: minmax(0, 1fr) minmax(18rem, .4fr); gap: var(--lv-section-gap); align-items: start;
  }
  body.learning-studio #panel-karten > :is(.section-heading, #karten-exam-prep) { grid-column: 1 / -1; }
  body.learning-studio #panel-karten > :is(.lk-entry, #karten-status, #karten-root) { grid-column: 1; }
  body.learning-studio #panel-karten > :is(#karten-stats, #karten-notices, #karten-shared, #karten-transfer) { grid-column: 2; }
}
@container panel (min-width: 62rem) {
  body.learning-studio .reader-workspace.has-task-preview { display: grid; grid-template-columns: minmax(0, 1fr) minmax(18rem, .35fr); gap: 1.25rem; }
  body.learning-studio .reader-task-preview { grid-column: 2; grid-row: 1; position: sticky; top: 1rem; max-height: calc(100dvh - 2rem); overflow-y: auto; }
}
@container panel (max-width: 61.99rem) {
  body.learning-studio .reader-workspace.has-task-preview { display: block; }
  body.learning-studio .reader-task-preview { position: static; max-height: none; }
}
@container panel (max-width: 42rem) {
  body.learning-studio :is(.home-welcome, .home-local, .course-overview-grid,
  .course-banner:not(.course-banner-compact), .studio-topic-intro, .studio-lesson-banner) { grid-template-columns: minmax(0, 1fr); gap: 1rem; }
  body.learning-studio .exams :is(.ex-study-layout, .ex-lesson-workspace) { grid-template-columns: minmax(0, 1fr); }
  body.learning-studio .exams .ex-study-nav { position: static; max-height: none; }
}
@container (max-width: 30rem) {
  body.learning-studio :is(.form-row, .reader-display-fields, .ex-form-grid, .prep-form-grid, .profile-grid, .settings-grid),
  .admin-form-grid { grid-template-columns: minmax(0, 1fr); }
  body.learning-studio :is(.reader-paging, .section-actions, .question-actions, .thread-actions, .course-actions),
  .admin-dialog-actions { flex-wrap: wrap; gap: .5rem; }
  body.learning-studio .reader-paging button { flex: 1 1 auto; }
  body.learning-studio .reader-position { flex-basis: 100%; order: -1; }
  .landing-page .answer-row { flex-wrap: wrap; }
  .landing-page .answer-row input { flex: 1 1 10rem; }
  .landing-page .answer-row button { flex: 1 1 auto; }
}

/* Decorative covers crop; source pages and scientific diagrams never do. */
body.learning-studio :is(.learning-artwork, .studio-artwork, .course-cover img,
.course-topic-art img, .studio-hero-art, .studio-lesson-art) {
  display: block; width: 100%; max-width: 100%; height: 100%; object-fit: cover;
  object-position: var(--lv-focal, center);
}
/* Authored field diagrams are meaning-bearing; keep their full frame. */
body.learning-studio :is(.course-cover img[src$=".svg"], .course-topic-art img[src$=".svg"]) { object-fit: contain; background: var(--soft, #e2eee9); }
body.learning-studio :is(.course-cover, .course-topic-art) { aspect-ratio: 4 / 3; }
body.learning-studio .home-welcome > *, body.learning-studio .home-welcome .studio-home-art { min-width: 0; }
body.learning-studio .home-welcome .studio-home-art {
  width: 100%; max-width: 100%; aspect-ratio: 16 / 10; min-height: 0; max-height: 30rem;
  align-self: stretch; justify-self: stretch; border: 0; border-radius: 8px;
}
body.learning-studio .home-welcome .studio-home-art > .studio-hero-art { min-height: 0; height: 100%; }
body.learning-studio :is(.course-banner:not(.course-banner-compact) .course-cover,
.studio-topic-intro > .studio-lesson-art, .studio-lesson-banner > .studio-lesson-art) { aspect-ratio: 16 / 9; min-height: 0; }
body.learning-studio :is(.source-image, .course-document-preview, .figure-svg, .chem-visual svg) { max-width: 100%; object-fit: contain; }
body.learning-studio .home-welcome .artwork-unavailable { display: none; }
body.learning-studio .home-welcome:has(.artwork-unavailable) { grid-template-columns: minmax(0, 1fr); }
body.learning-studio :is(.course-cover, .course-topic-art).artwork-unavailable { aspect-ratio: auto; min-height: 3rem; height: 3rem; }
@container panel (max-width: 42rem) {
  body.learning-studio .home-welcome .studio-home-art { max-height: 15rem; aspect-ratio: 16 / 7; }
}

/* Public pages share the scale. The sign-in form is a separate, unframed band. */
/* Landing composition lives in landing.css; shared controls above still apply. */
.access-page { padding-inline: var(--lv-gutter); background: var(--paper); }

.access-card { width: min(100%, 38rem); border-radius: 16px; background: var(--surface); box-shadow: var(--lv-gloss-shadow); }
.access-card h1 { font-family: var(--sans); font-size: 2rem; line-height: 1.25; }
.access-card :is(label, .form-help, .field-optional, nav) { font-size: .875rem; }
.access-card > p:not(.login-kicker) { font-size: 1rem; }
.admin-shell { width: 100%; max-width: none; padding: 1.5rem var(--lv-gutter); }
.admin-shell :is(h1, h2, h3) { font-family: var(--sans); line-height: 1.3; }
.admin-shell h1 { font-size: 2rem; }
.admin-card { padding: 1.25rem 0; margin: 0; border: 0; border-top: 1px solid var(--line); border-radius: 0; box-shadow: none; }
.admin-card :is(label, .admin-meta, .status-chip, legend) { font-size: .875rem; }
.admin-card form { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 14rem), 1fr)); }
.admin-card label { min-width: 0; }
.admin-card :is(input, select, textarea) { width: 100%; }
.admin-card form > :is(fieldset, textarea) { grid-column: 1 / -1; }
.admin-shell .admin-actions button { min-height: 44px; }
.admin-shell #invite-form button { background: var(--lv-action); color: var(--lv-on-action); border-color: #367e72; }
.moodle-shell, .pote-shell { width: 100%; max-width: none; margin-inline: auto; padding-inline: var(--lv-gutter); }
.moodle-page .site-header, .potepedia-page .site-header { max-width: none; padding-inline: var(--lv-gutter); }
.moodle-hero, .pote-hero { background: transparent; color: var(--ink); border: 0; border-radius: 0; box-shadow: none; padding: 1.5rem 0; grid-template-columns: minmax(0, 1fr); }
.moodle-hero::before, .pote-hero::before, .moodle-hero-art, .pote-hero-art { display: none; }
.moodle-hero :is(h1, .eyebrow, .moodle-hero-link), .pote-hero :is(h1, .eyebrow, .pote-hero-link),
.moodle-hero-copy > p:not(.eyebrow), .pote-hero-copy > p:not(.eyebrow) { color: var(--ink); }
.moodle-page :is(.moodle-nav a, .moodle-nav span, .moodle-deadline, .moodle-status),
.potepedia-page :is(.pote-nav a, .pote-nav span, .pote-status) { font-size: .875rem; }
.moodle-nav [aria-current], .pote-nav [aria-current] { background: var(--lv-action); color: var(--lv-on-action); }
.moodle-controls, .pote-controls { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr)); gap: 1rem; align-items: end; }
.moodle-tree-toolbar, .pote-tree-toolbar, .library-header-actions { display: flex; flex-wrap: wrap; gap: .75rem; align-items: center; justify-content: space-between; }
.moodle-page :is(h1, h2), .potepedia-page :is(h1, h2) { font-family: var(--sans); font-size: 1.75rem; line-height: 1.3; }
.moodle-page label, .potepedia-page label { font-size: .9375rem; }
/* Reading pages get a measured column; full-bleed marketing surfaces set their
   own measure per text block and opt out here. */
body:not(.learning-studio):not(.landing-page):not(.engineering-page):not(.pecs-page) > main:not(.admin-shell):not(.moodle-shell):not(.pote-shell):not(.access-page) { box-sizing: border-box; width: min(100% - 2rem, 70ch); }
body.learning-studio :is(dialog, .lv-finder, .community-dialog), .admin-shell dialog {
  max-width: calc(100% - 2rem); max-height: calc(100dvh - 2rem); overflow: auto;
  border: 1px solid var(--line); border-radius: 16px; background: var(--surface); box-shadow: var(--lv-gloss-shadow);
}
body.learning-studio :is(.lv-finder, .community-dialog) { width: min(60rem, calc(100% - 2rem)); }
body.learning-studio .finder-heading h2 { font-size: 1.5rem; }
body.learning-studio .reader-task-preview, body.learning-studio .exams .ex-study-nav { scrollbar-gutter: stable; }
@supports (background: color-mix(in srgb, white, black)) {
  :root, html[data-theme] { --lv-material: var(--glass-shell); }
}
@supports ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  body.learning-studio .tabs, body.learning-studio .app-menu, .landing-page .site-header,
  body.learning-studio :is(.question-card, .viewer-card, .card, .exams .ex-question,
  .exams .ex-practice-question, .access-card, .login-fields, .demo) {
    background: linear-gradient(180deg, #ffffff18, transparent), var(--lv-material);
    -webkit-backdrop-filter: blur(11px) saturate(116%); backdrop-filter: blur(11px) saturate(116%);
  }
  body.learning-studio :is(.question-card, .viewer-card, .card, .exams .ex-question,
  .exams .ex-practice-question, .access-card, .login-fields, .demo) {
    background: var(--glass-reading);
  }
}
@media (hover: hover) and (pointer: fine) and (prefers-reduced-motion: no-preference) {
  body.learning-studio button, .landing-page button, .landing-page .button { transition: border-color 140ms ease, box-shadow 140ms ease; }
  body.learning-studio button:not(:disabled):hover { border-color: var(--green); }
  .landing-page :is(button, .button):hover { filter: none; box-shadow: 0 0 0 2px var(--surface), 0 0 0 3px var(--green); }
}
@media (prefers-reduced-transparency: reduce), (prefers-contrast: more) {
  body.learning-studio :is(.tabs, .app-menu, .lv-finder, .community-dialog, dialog, .card,
  .question-card, .viewer-card),
  .landing-page .site-header, .landing-page .demo, .landing-page .login-fields, .access-card, .admin-shell dialog {
    background: var(--surface); -webkit-backdrop-filter: none; backdrop-filter: none; box-shadow: none;
  }
  body.learning-studio :is(button, input, select, textarea, .course-tile),
  .landing-page :is(button, .button, input, select) { border-color: currentColor; }
}
@media (prefers-reduced-motion: reduce) {
  body.learning-studio *, .landing-page *, .access-page *, .admin-shell *, .moodle-page *, .potepedia-page * {
    scroll-behavior: auto !important; animation: none !important; transition: none !important;
  }
}
@media (forced-colors: active) {
  body.learning-studio :is(.tabs, .app-menu, .card, .course-tile, .course-topic-card,
  .family-card, .topic-card, .lv-finder, .community-dialog, dialog),
  .landing-page :is(.login-card, .demo, .site-header), .access-card, .admin-card {
    border: 1px solid CanvasText; background: Canvas; color: CanvasText; box-shadow: none;
  }
  body.learning-studio :is(button, .home-primary, .course-primary, .exams .ex-primary),
  .landing-page :is(button, .button), .access-card button, .admin-shell button { border: 2px solid ButtonText; box-shadow: none; }
}