/* Optional account-level presentation inspired by the former Material for MkDocs site. */
.oldschool-toggle { display: inline-flex; align-items: center; gap: 7px; padding: 8px 11px; border: 1px solid var(--line); border-radius: 7px; color: var(--muted); background: transparent; font: 700 10px "JetBrains Mono", monospace; cursor: pointer; }
.oldschool-toggle:hover { border-color: var(--blue); color: var(--blue); }
.oldschool-toggle[aria-pressed=true] { border-color: #5c6bc0; color: #8c9eff; }
.student-oldschool-preference { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin-top: 22px; padding: 20px 22px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); }
.student-oldschool-preference > div { display: grid; gap: 5px; }
.student-oldschool-preference span { color: var(--blue); font: 800 9px "JetBrains Mono", monospace; letter-spacing: .1em; text-transform: uppercase; }
.student-oldschool-preference h2 { margin: 0; font-size: 17px; }
.student-oldschool-preference p { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.5; }
.student-oldschool-preference button { flex: none; display: inline-flex; align-items: center; gap: 8px; padding: 10px 13px; border: 1px solid var(--blue); border-radius: 7px; color: var(--blue); background: transparent; font-weight: 800; cursor: pointer; }
.student-chat-archive { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin-top: 22px; padding: 20px 22px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); }
.student-chat-archive > div { display: grid; gap: 5px; }
.student-chat-archive span { color: var(--blue); font: 800 9px "JetBrains Mono", monospace; letter-spacing: .1em; text-transform: uppercase; }
.student-chat-archive h2 { margin: 0; font-size: 17px; }
.student-chat-archive p { max-width: 720px; margin: 0; color: var(--muted); font-size: 12px; line-height: 1.5; }
.student-chat-archive code { color: var(--blue); }
.student-chat-history-actions { flex: none; display: flex; align-items: center; gap: 8px; }
.student-chat-history-actions button, .student-chat-history-actions a { padding: 11px 14px; border: 1px solid var(--lime); border-radius: 7px; font-weight: 900; cursor: pointer; text-decoration: none !important; }
.student-chat-history-actions button { color: #10170a; background: var(--lime); }
.student-chat-history-actions a { color: var(--blue) !important; border-color: var(--line); background: transparent; }
.student-chat-history-actions button:hover, .student-chat-history-actions a:hover { filter: brightness(1.08); transform: translateY(-1px); }
.oldschool-season-tabs, .oldschool-lesson-nav { display: none; }
.course-lesson.status-revision { grid-template-columns: 39px minmax(0, 1fr) 20px; grid-template-rows: auto auto; row-gap: 5px; }
.course-lesson.status-revision .course-lesson-number { grid-column: 1; grid-row: 1 / 3; }
.course-lesson.status-revision .course-lesson-copy { grid-column: 2; grid-row: 1; }
.course-lesson.status-revision .course-status { grid-column: 2; grid-row: 2; justify-self: start; }
.course-lesson.status-revision .course-lesson-arrow { grid-column: 3; grid-row: 1 / 3; }

html[data-course-layout=oldschool] { --oldschool-primary: #3f51b5; --oldschool-bg: #1e2129; --oldschool-surface: #272a35; --oldschool-text: rgba(255,255,255,.87); --oldschool-muted: rgba(255,255,255,.56); --oldschool-line: rgba(255,255,255,.12); --oldschool-code: #16181d; }
html[data-course-layout=oldschool][data-course-theme=light] { --oldschool-primary: #3f51b5; --oldschool-bg: #fff; --oldschool-surface: #fff; --oldschool-text: rgba(0,0,0,.87); --oldschool-muted: rgba(0,0,0,.58); --oldschool-line: rgba(0,0,0,.12); --oldschool-code: #f5f5f5; }
html[data-course-layout=oldschool] body.course-body { color: var(--oldschool-text); background: var(--oldschool-bg); font-family: Roboto, Arial, sans-serif; }
html[data-course-layout=oldschool] body.course-body::before, html[data-course-layout=oldschool] .course-hero-grid { display: none; }
html[data-course-layout=oldschool] .container { width: min(1220px, calc(100% - 32px)); }
html[data-course-layout=oldschool] .course-header { position: sticky; top: 0; z-index: 40; min-height: 48px; border: 0; background: var(--oldschool-primary); box-shadow: 0 1px 4px rgba(0,0,0,.35); backdrop-filter: none; }
html[data-course-layout=oldschool] .course-nav { min-height: 48px; }
html[data-course-layout=oldschool] .nav-logo img { width: 31px; height: 31px; border-radius: 0; filter: none; }
html[data-course-layout=oldschool] .nav-logo-copy strong { color: #fff; font: 500 18px Roboto, Arial, sans-serif; letter-spacing: 0; text-transform: none; }
html[data-course-layout=oldschool] .nav-logo-copy small { display: none; }
html[data-course-layout=oldschool] .course-user, html[data-course-layout=oldschool] .course-header-actions { gap: 11px; }
html[data-course-layout=oldschool] .lesson-account strong, html[data-course-layout=oldschool] .lesson-account small, html[data-course-layout=oldschool] .lesson-account small b, html[data-course-layout=oldschool] .lesson-account-name button, html[data-course-layout=oldschool] .course-header-actions > a { color: rgba(255,255,255,.9); }
html[data-course-layout=oldschool] .course-header button[data-course-logout], html[data-course-layout=oldschool] .course-header .oldschool-toggle { border-color: rgba(255,255,255,.38); color: #fff; background: transparent; border-radius: 3px; }
html[data-course-layout=oldschool] .course-header .theme-toggle { border: 1px solid rgba(255,255,255,.65) !important; border-radius: 4px !important; color: #fff !important; background: rgba(0,0,0,.2) !important; box-shadow: inset 0 0 0 1px rgba(255,255,255,.08); }
html[data-course-layout=oldschool] .course-header .theme-toggle:hover { border-color: #fff !important; color: #fff !important; background: rgba(0,0,0,.32) !important; transform: none; }
html[data-course-layout=oldschool] .course-header .oldschool-toggle[aria-pressed=true] { background: rgba(0,0,0,.15); }
html[data-course-layout=oldschool] .oldschool-season-tabs { display: block; position: sticky; top: 48px; z-index: 35; height: 47px; background: var(--oldschool-primary); box-shadow: 0 2px 3px rgba(0,0,0,.18); }
html[data-course-layout=oldschool] .oldschool-season-tabs > div { width: min(1220px, calc(100% - 32px)); height: 100%; margin: 0 auto; display: flex; align-items: stretch; gap: 4px; }
html[data-course-layout=oldschool] .oldschool-season-tabs a { display: flex; align-items: center; padding: 0 17px; color: rgba(255,255,255,.72); font-size: 13px; text-decoration: none; }
html[data-course-layout=oldschool] .oldschool-season-tabs a:hover { color: #fff; background: rgba(0,0,0,.1); }

/* Cabinet and catalogue: retain function, remove dashboard ornament. */
html[data-course-layout=oldschool] .monthly-bonus-winner-wrap, html[data-course-layout=oldschool] .course-contribution-section, html[data-course-layout=oldschool] .course-roadmap, html[data-course-layout=oldschool] .course-standing, html[data-course-layout=oldschool] .student-community-card:not([data-student-gitlab]), html[data-course-layout=oldschool] .course-progress-help { display: none !important; }
html[data-course-layout=oldschool] .course-hero { padding: 38px 0 8px; background: none; }
html[data-course-layout=oldschool] .course-hero-inner.progress-only { display: block; }
html[data-course-layout=oldschool] .course-progress-card { padding: 0; border: 0; border-radius: 0; background: none; box-shadow: none; }
html[data-course-layout=oldschool] .course-progress-dashboard { display: block; }
html[data-course-layout=oldschool] .course-progress-primary { padding: 22px 24px; border: 1px solid var(--oldschool-line); border-radius: 4px; background: var(--oldschool-surface); }
html[data-course-layout=oldschool] .course-progress-summary span, html[data-course-layout=oldschool] .course-progress-primary p, html[data-course-layout=oldschool] .course-season-standing small { color: var(--oldschool-muted); }
html[data-course-layout=oldschool] .course-progress-summary strong { color: var(--oldschool-primary); }
html[data-course-layout=oldschool] .course-progress-track { accent-color: var(--oldschool-primary); }
html[data-course-layout=oldschool] .requirements-entry, html[data-course-layout=oldschool] .student-community-card[data-student-gitlab], html[data-course-layout=oldschool] .student-subscription-card, html[data-course-layout=oldschool] .student-submission-status, html[data-course-layout=oldschool] .student-education-document, html[data-course-layout=oldschool] .student-oldschool-preference, html[data-course-layout=oldschool] .student-chat-archive { margin-top: 14px; padding: 17px 19px; border: 1px solid var(--oldschool-line); border-radius: 4px; color: var(--oldschool-text); background: var(--oldschool-surface); box-shadow: none; }
html[data-course-layout=oldschool] .student-community-card[data-student-gitlab] { display: grid !important; }
html[data-course-layout=oldschool] .student-community-card[data-student-gitlab] > a { border-radius: 3px; box-shadow: none; }
html[data-course-layout=oldschool] .student-oldschool-preference, html[data-course-layout=oldschool] .student-chat-archive { display: flex; }
html[data-course-layout=oldschool] .student-education-document { margin-top: 28px; }
html[data-course-layout=oldschool] .student-chat-history-actions button, html[data-course-layout=oldschool] .student-chat-history-actions a { border-radius: 3px; color: #fff !important; border-color: var(--oldschool-primary); background: var(--oldschool-primary); }
@media (max-width: 700px) { .student-chat-archive { align-items: stretch; flex-direction: column; } .student-chat-history-actions { align-items: stretch; flex-direction: column; } .student-chat-history-actions button, .student-chat-history-actions a { text-align: center; } }
html[data-course-layout=oldschool] .course-catalog { padding: 28px 0 70px; background: none; }
html[data-course-layout=oldschool] .course-section-heading { margin-bottom: 22px; padding-bottom: 12px; border-bottom: 1px solid var(--oldschool-line); }
html[data-course-layout=oldschool] .course-section-heading .eyebrow, html[data-course-layout=oldschool] .course-legend { display: none; }
html[data-course-layout=oldschool] .course-section-heading h2 { font: 400 28px Roboto, Arial, sans-serif; }
html[data-course-layout=oldschool] #course-seasons { display: grid; gap: 12px; }
html[data-course-layout=oldschool] .course-season { border: 1px solid var(--oldschool-line); border-radius: 4px; background: var(--oldschool-surface); box-shadow: none; overflow: hidden; }
html[data-course-layout=oldschool] .course-season-head { padding: 14px 17px; color: var(--oldschool-text); background: transparent; }
html[data-course-layout=oldschool] .course-season-number { width: 35px; height: 35px; border-radius: 2px; color: #fff; background: var(--oldschool-primary); font-family: "Roboto Mono", monospace; }
html[data-course-layout=oldschool] .course-season-head strong { font-size: 15px; }
html[data-course-layout=oldschool] .course-season-head small { color: var(--oldschool-muted); }
html[data-course-layout=oldschool] .course-lessons { border-top: 1px solid var(--oldschool-line); }
html[data-course-layout=oldschool] .course-lesson { min-height: 43px; padding: 8px 14px; border-bottom: 1px solid var(--oldschool-line); color: var(--oldschool-text); background: transparent; }
html[data-course-layout=oldschool] .course-lesson:hover { background: color-mix(in srgb, var(--oldschool-primary) 9%, transparent); transform: none; }
html[data-course-layout=oldschool] .course-lesson-number { font: 500 12px "Roboto Mono", monospace; color: var(--oldschool-primary); }
html[data-course-layout=oldschool] .course-lesson-copy strong { font-size: 13px; font-weight: 400; }
html[data-course-layout=oldschool] .course-lesson-copy small, html[data-course-layout=oldschool] .course-lesson-arrow { display: none; }
html[data-course-layout=oldschool] .course-status { border: 0; border-radius: 2px; font-size: 9px; }
html[data-course-layout=oldschool] .course-footer { border-top: 1px solid var(--oldschool-line); color: var(--oldschool-muted); background: var(--oldschool-bg); }

/* Lesson page: MkDocs-like season tabs, left tree and restrained article. */
html[data-course-layout=oldschool] .lesson-hero { padding: 26px 0 10px; border: 0; background: none; }
html[data-course-layout=oldschool] .lesson-hero-inner { min-height: auto; align-items: end; }
html[data-course-layout=oldschool] .lesson-hero h1 { color: var(--oldschool-text); font: 400 28px Roboto, Arial, sans-serif; }
html[data-course-layout=oldschool] .lesson-meta { color: var(--oldschool-primary); font: 500 11px "Roboto Mono", monospace; }
html[data-course-layout=oldschool] .lesson-hero-tools .lesson-content-style, html[data-course-layout=oldschool] .lesson-hero-tools .lesson-position { display: none; }
html[data-course-layout=oldschool] .lesson-sidebar-toggle { border-color: var(--oldschool-line); border-radius: 3px; color: var(--oldschool-primary); background: transparent; }
html[data-course-layout=oldschool] .lesson-sidebar-toggle:hover { border-color: var(--oldschool-primary); color: var(--oldschool-primary); }
html[data-course-layout=oldschool] .lesson-layout { max-width: 1220px; display: grid; grid-template-columns: 210px minmax(0, 1fr) 230px; gap: 34px; align-items: start; }
html[data-course-layout=oldschool] body.lesson-page.lesson-sidebar-hidden .lesson-layout { grid-template-columns: 210px minmax(0, 1fr); gap: 34px; }
html[data-course-layout=oldschool] body.lesson-page.lesson-sidebar-hidden .lesson-article { width: auto; min-width: 0; }
html[data-course-layout=oldschool] body.lesson-page.lesson-sidebar-hidden .lesson-sidebar { display: none; }
html[data-course-layout=oldschool] .oldschool-lesson-nav { display: block; position: sticky; top: 112px; max-height: calc(100vh - 128px); overflow: auto; padding: 10px 0; color: var(--oldschool-text); font-size: 13px; }
html[data-course-layout=oldschool] .oldschool-nav-home { display: block; margin-bottom: 11px; padding: 9px 10px; color: var(--oldschool-text); font-weight: 700; text-decoration: none; }
html[data-course-layout=oldschool] .oldschool-lesson-nav details { border-top: 1px solid var(--oldschool-line); }
html[data-course-layout=oldschool] .oldschool-lesson-nav summary { padding: 10px; color: var(--oldschool-text); font-weight: 700; cursor: pointer; }
html[data-course-layout=oldschool] .oldschool-lesson-nav nav { display: grid; }
html[data-course-layout=oldschool] .oldschool-lesson-nav nav a, html[data-course-layout=oldschool] .oldschool-lesson-nav nav span { padding: 7px 10px 7px 18px; color: var(--oldschool-muted); text-decoration: none; }
html[data-course-layout=oldschool] .oldschool-lesson-nav nav a:hover, html[data-course-layout=oldschool] .oldschool-lesson-nav nav a.active { color: var(--oldschool-primary); }
html[data-course-layout=oldschool] .oldschool-lesson-nav nav a.active { font-weight: 700; }
html[data-course-layout=oldschool] .oldschool-lesson-nav nav span { opacity: .38; }
html[data-course-layout=oldschool] .lesson-article { min-width: 0; padding: 8px 0 60px; border: 0; border-radius: 0; color: var(--oldschool-text); background: none; box-shadow: none; }
html[data-course-layout=oldschool] .lesson-markdown { color: var(--oldschool-text); font: 400 15px/1.65 Roboto, Arial, sans-serif; }
html[data-course-layout=oldschool] .lesson-markdown h1, html[data-course-layout=oldschool] .lesson-markdown h2, html[data-course-layout=oldschool] .lesson-markdown h3 { color: var(--oldschool-text); font-family: Roboto, Arial, sans-serif; font-weight: 500; }
html[data-course-layout=oldschool] .lesson-markdown h2 { margin-top: 1.8em; padding: 0 0 .35em; border-bottom: 1px solid var(--oldschool-line); }
html[data-course-layout=oldschool] .lesson-markdown a { color: var(--oldschool-primary); }
html[data-course-layout=oldschool] .lesson-markdown pre { border: 0; border-radius: 3px; background: var(--oldschool-code); box-shadow: none; }
html[data-course-layout=oldschool] .lesson-markdown code { font-family: "Roboto Mono", monospace; }
html[data-course-layout=oldschool] .lesson-markdown .lesson-callout { border-radius: 3px; box-shadow: none; }
html[data-course-layout=oldschool] .lesson-sidebar { position: sticky; top: 112px; }
html[data-course-layout=oldschool] .lesson-support, html[data-course-layout=oldschool] .lesson-review-status, html[data-course-layout=oldschool] .lesson-public-cta { border: 1px solid var(--oldschool-line); border-radius: 4px; color: var(--oldschool-text); background: var(--oldschool-surface); box-shadow: none; }
html[data-course-layout=oldschool] .lesson-support img, html[data-course-layout=oldschool] .lesson-support > span { display: none; }
html[data-course-layout=oldschool] .lesson-support h2 { font-size: 16px; }
html[data-course-layout=oldschool] .lesson-support p { color: var(--oldschool-muted); }
html[data-course-layout=oldschool] .lesson-support button { padding: 7px 0; border: 0; border-radius: 0; color: var(--oldschool-primary); background: transparent; box-shadow: none; text-align: left; }
html[data-course-layout=oldschool] .lesson-support button:hover { color: var(--oldschool-primary); text-decoration: underline; transform: none; }
html[data-course-layout=oldschool] .homework-chat-sidebar-button, html[data-course-layout=oldschool] .homework-chat-sidebar-button.pending { border: 1px solid var(--oldschool-primary); border-radius: 3px; color: #fff; background: var(--oldschool-primary); box-shadow: none; }
html[data-course-layout=oldschool] .homework-chat-sidebar-button:hover { filter: brightness(1.08); transform: none; box-shadow: none; }
html[data-course-layout=oldschool] .homework-chat-sidebar-button > span { background: rgba(255,255,255,.16); color: #fff; }
html[data-course-layout=oldschool] .lesson-finish { border-top: 1px solid var(--oldschool-line); background: none; }
html[data-course-layout=oldschool] .lesson-bottom-navigation a { border-radius: 3px; background: var(--oldschool-surface); box-shadow: none; }

@media (max-width: 1000px) {
  html[data-course-layout=oldschool] .lesson-layout { grid-template-columns: 190px minmax(0, 1fr); }
  html[data-course-layout=oldschool] .lesson-sidebar { grid-column: 2; position: static; }
}
@media (max-width: 760px) {
  .student-oldschool-preference { align-items: stretch; flex-direction: column; }
  html[data-course-layout=oldschool] .oldschool-season-tabs { overflow-x: auto; }
  html[data-course-layout=oldschool] .oldschool-season-tabs > div { width: max-content; min-width: 100%; }
  html[data-course-layout=oldschool] .lesson-layout { display: block; }
  html[data-course-layout=oldschool] .oldschool-lesson-nav { position: static; max-height: none; margin-bottom: 20px; border-bottom: 1px solid var(--oldschool-line); }
  html[data-course-layout=oldschool] .course-header .oldschool-toggle b { display: none; }
  html[data-course-layout=oldschool] .lesson-account { display: none; }
}