/* Сервис «Обучение»: список курсов, программа курса и страница урока.
   Цвета и размеры берутся из токенов platform.css. */

:root {
  --code-bg: #111114;
  --code-text: #e8e8e3;
  --code-keyword: #c8f031;
  --code-string: #f5c26b;
  --code-number: #ff9e64;
  --code-comment: #6f6f7a;
  --code-function: #8fd3ff;
  --code-class: #ffd166;
  --code-builtin: #c3a6ff;
  --header-h: 64px;
}

/* ---------- Список курсов ---------- */

.course-list { list-style: none; display: grid; gap: 20px; padding-bottom: 72px; }

.course-card {
  position: relative;
  display: grid;
  gap: 24px;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  background: var(--surface);
  transition: border-color .2s var(--ease);
}
@media (min-width: 900px) { .course-card { grid-template-columns: 1.1fr 1fr; padding: 36px; gap: 40px; } }
.course-card:hover { border-color: var(--border-strong); }
.course-card:focus-within { box-shadow: 0 0 0 3px var(--focus); }
.course-card__body { display: flex; flex-direction: column; align-items: flex-start; gap: 12px; }
.course-card h2 { font-size: clamp(24px, 3vw, 34px); }
.course-card h2 a { color: var(--text); text-decoration: none; }
.course-card h2 a::after { content: ""; position: absolute; inset: 0; z-index: 1; }
.course-card h2 a:focus-visible { outline: none; }
.course-card p { color: var(--muted); }
.course-card__meta { font-size: 14px; }
.course-card .btn { margin-top: auto; }
.course-card__sections { list-style: none; display: grid; gap: 6px; align-content: start; }
.course-card__sections li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: var(--radius-s);
  background: var(--surface-2);
  font-size: 15px;
}
.course-card__icon { width: 22px; text-align: center; }
.course-card__count { margin-left: auto; font-family: var(--mono); font-size: 13px; color: var(--muted); }

/* ---------- Страница курса ---------- */

.course-hero { padding: 16px 0 32px; }
.course-hero h1 { font-size: clamp(30px, 5.5vw, 56px); margin: 14px 0 14px; max-width: 18ch; }
.course-hero__actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }

.course-about { display: grid; gap: 24px; margin-bottom: 56px; }
@media (min-width: 900px) { .course-about { grid-template-columns: 1fr 1fr; align-items: start; gap: 40px; } }
.course-about .prose p { color: var(--muted); }
.course-about .panel h2 { font-size: 20px; margin-bottom: 14px; font-family: var(--font); letter-spacing: 0; }

.course-program__head { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 24px; }
.course-program__head h2 { font-size: clamp(26px, 3.2vw, 36px); }
.course-program__head .search { flex: 1 1 320px; max-width: 480px; }
.course-program .search-status { margin: 0 0 16px; }
.course-program .search-status a { margin-left: 8px; }

/* Темы курса */
.topic-grid {
  list-style: none;
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr));
  padding-bottom: 72px;
}
.topic-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 22px 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  transition: border-color .2s var(--ease), transform .2s var(--ease);
}
.topic-card:hover { border-color: var(--border-strong); transform: translateY(-2px); }
.topic-card:focus-within { box-shadow: 0 0 0 3px var(--focus); }
.topic-card__top { display: flex; align-items: center; justify-content: space-between; }
.topic-card__icon { font-size: 26px; line-height: 1; }
.topic-card__num { font-family: var(--mono); font-size: 13px; color: var(--muted); }
.topic-card__icon + .topic-card__badge { margin-right: auto; margin-left: 12px; }
.topic-card__badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-ink);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0;
  text-transform: none;
  vertical-align: middle;
}

/* Важная тема: зелёная рамка и мягкая подсветка */
.topic-card--key {
  border-color: rgba(200, 240, 49, .45);
  background: linear-gradient(180deg, var(--accent-soft), transparent 55%), var(--surface);
}
.topic-card--key:hover { border-color: var(--accent-text); }
.topic-card--key .topic-card__num { color: var(--accent-text); }
.topic-card h3 { font-family: var(--display); font-size: 21px; font-weight: 600; letter-spacing: -.02em; }
.topic-card h3 a { color: var(--text); text-decoration: none; }
.topic-card h3 a::after { content: ""; position: absolute; inset: 0; z-index: 1; }
.topic-card h3 a:focus-visible { outline: none; }
.topic-card > p { color: var(--muted); font-size: 15px; }
.topic-card__lessons { list-style: none; display: grid; gap: 4px; font-size: 14px; color: var(--muted); }
.topic-card__lessons li { padding-left: 14px; position: relative; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topic-card__lessons li::before { content: ""; position: absolute; left: 0; top: .6em; width: 5px; height: 5px; border-radius: 50%; background: var(--border-strong); }
.topic-card__more { color: var(--text); }
.topic-card__meta { display: flex; justify-content: space-between; gap: 8px; margin-top: auto; padding: 12px 0 14px; font-size: 13px; color: var(--muted); }

/* Страница темы */
.topic-hero { padding: 16px 0 32px; }
.topic-hero .eyebrow span { font-size: 16px; letter-spacing: 0; }
.topic-hero h1 { font-size: clamp(30px, 5.5vw, 52px); margin: 12px 0 14px; }
.topic-hero__meta { margin-top: 12px; font-size: 14px; color: var(--muted); }

.topic-lessons { list-style: none; display: grid; gap: 10px; max-width: 880px; }
.topic-lesson {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  padding: 18px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  transition: border-color .15s;
}
.topic-lesson:hover { border-color: var(--accent-text); color: var(--text); }
.topic-lesson__num { font-family: var(--mono); font-size: 14px; color: var(--accent-text); padding-top: 2px; }
.topic-lesson__body { display: grid; gap: 6px; flex: 1; min-width: 0; }
.topic-lesson__body b { font-size: 18px; font-weight: 600; line-height: 1.35; }
.topic-lesson__body span { color: var(--muted); font-size: 15px; line-height: 1.55; }
.topic-lesson__body small { font-size: 13px; color: var(--muted); }
.topic-pager { max-width: 880px; margin: 32px 0 72px; }

.lesson-list { list-style: none; display: grid; gap: 2px; }
.lesson-list a {
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 44px;
  padding: 8px 10px;
  border-radius: var(--radius-s);
  color: var(--text);
  text-decoration: none;
}
.lesson-list a:hover { background: var(--surface-2); color: var(--text); }
.lesson-list__num { font-family: var(--mono); font-size: 13px; color: var(--muted); min-width: 2ch; }
.lesson-list__title { display: grid; gap: 2px; }
.lesson-list__title small { font-size: 13px; color: var(--muted); }
.lesson-list--results { padding-bottom: 72px; }
.lesson-list--results a { padding: 12px 14px; border: 1px solid var(--border); background: var(--surface); }

/* ---------- Страница урока ---------- */

.lesson-layout { display: grid; gap: 0 40px; padding-bottom: 72px; }
@media (min-width: 1024px) { .lesson-layout { grid-template-columns: 260px minmax(0, 1fr); } }
@media (min-width: 1360px) { .lesson-layout { grid-template-columns: 260px minmax(0, 1fr) 220px; } }

.lesson { min-width: 0; max-width: 780px; }

/* Программа курса: на мобильных — раскрывающийся блок, на десктопе — боковая колонка */
.lesson-nav { padding-top: 20px; }
.lesson-nav__toggle > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 48px;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  background: var(--surface);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.lesson-nav__toggle > summary::-webkit-details-marker { display: none; }
.lesson-nav__toggle > summary span { font-family: var(--mono); font-size: 13px; font-weight: 400; color: var(--muted); }
.lesson-nav__body { padding: 12px 4px 4px; }
@media (min-width: 1024px) {
  .lesson-nav {
    position: sticky;
    top: var(--header-h);
    align-self: start;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    padding: 24px 4px 24px 0;
    scrollbar-width: thin;
  }
  .lesson-nav__toggle > summary { display: none; }
  .lesson-nav__body { padding: 0; }
}
.lesson-nav__course { display: block; font-family: var(--display); font-size: 15px; font-weight: 600; color: var(--text); text-decoration: none; line-height: 1.3; margin-bottom: 12px; }
.lesson-nav__course:hover { color: var(--accent-text); }

.lesson-nav__section { border-top: 1px solid var(--border); }
.lesson-nav__section > summary {
  padding: 10px 4px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: 8px;
}
.lesson-nav__section > summary::-webkit-details-marker { display: none; }
.lesson-nav__section > summary::after { content: "+"; color: var(--muted); font-weight: 400; }
.lesson-nav__section[open] > summary::after { content: "−"; }
.lesson-nav__section ol { list-style: none; padding-bottom: 10px; }
.lesson-nav__section a {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 6px 8px;
  border-radius: 8px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--muted);
  text-decoration: none;
}
.lesson-nav__section a:hover { color: var(--text); background: var(--surface-2); }
.lesson-nav__section a[aria-current="page"] { color: var(--text); background: var(--surface-2); box-shadow: inset 2px 0 0 var(--accent); }

.lesson__head { padding: 12px 0 28px; }
.lesson__head h1 { font-size: clamp(28px, 4.5vw, 44px); margin-top: 10px; }

/* Содержание урока */
.lesson-toc ul { list-style: none; }
.lesson-toc a { display: block; padding: 4px 0; font-size: 14px; line-height: 1.4; color: var(--muted); text-decoration: none; }
.lesson-toc a:hover, .lesson-toc a.is-active { color: var(--text); }
.lesson-toc__l3 a { padding-left: 14px; font-size: 13px; }
.lesson-toc--inline { margin-bottom: 28px; padding: 12px 16px; border: 1px solid var(--border); border-radius: var(--radius-s); background: var(--surface); }
.lesson-toc--inline summary { cursor: pointer; font-weight: 600; font-size: 15px; }
.lesson-toc--inline ul { margin-top: 10px; }
.lesson-toc--side { display: none; }
@media (min-width: 1360px) {
  .lesson-toc--inline { display: none; }
  .lesson-toc--side {
    display: block;
    position: sticky;
    top: var(--header-h);
    align-self: start;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    padding: 28px 0;
  }
  .lesson-toc--side > p { font-size: 13px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); margin-bottom: 10px; }
  .lesson-toc--side a.is-active { box-shadow: inset 2px 0 0 var(--accent-text); padding-left: 10px; }
  .lesson-toc--side .lesson-toc__l3 a.is-active { padding-left: 22px; }
}

/* ---------- Текст урока ---------- */

.lesson-prose { font-size: 17px; line-height: 1.7; overflow-wrap: break-word; }
.lesson-prose > * + * { margin-top: 18px; }
.lesson-prose h2, .lesson-prose h3, .lesson-prose h4 { scroll-margin-top: calc(var(--header-h) + 16px); }
.lesson-prose h2 { font-size: clamp(24px, 3vw, 30px); margin-top: 48px; }
.lesson-prose h3 { font-size: 21px; margin-top: 36px; font-weight: 600; }
.lesson-prose h4 { font-size: 18px; margin-top: 28px; font-weight: 600; }
.lesson-prose :is(h2, h3, h4) + * { margin-top: 12px; }
.lesson-prose ul, .lesson-prose ol { padding-left: 1.4em; }
.lesson-prose li + li { margin-top: 6px; }
.lesson-prose li > ul, .lesson-prose li > ol, .lesson-prose li > p + * { margin-top: 8px; }
.lesson-prose li::marker { color: var(--muted); }
.lesson-prose strong { font-weight: 600; color: var(--text); }
.lesson-prose hr { border: 0; border-top: 1px solid var(--border); margin: 36px 0; }
.lesson-prose img { display: block; max-width: 100%; height: auto; border-radius: var(--radius-s); background: #fff; }
.lesson-prose p > img:only-child { margin: 0 auto; }
.lesson-prose .caption { margin-top: 8px; font-size: 14px; color: var(--muted); }

.lesson-prose :not(pre) > code {
  padding: .12em .4em;
  border-radius: 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  font-family: var(--mono);
  font-size: .86em;
  white-space: break-spaces;
}

.lesson-prose blockquote {
  margin-left: 0;
  margin-right: 0;
  padding: 4px 0 4px 18px;
  border-left: 3px solid var(--border-strong);
  color: var(--muted);
}

.lesson-prose .callout {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  padding: 16px 20px;
  border-radius: var(--radius);
  background: var(--surface-2);
}
.lesson-prose .callout::before { content: attr(data-icon); font-size: 20px; line-height: 1.4; }
.lesson-prose .callout:not([data-icon])::before { content: "💡"; }
.lesson-prose .callout > * { grid-column: 2; margin: 0; }
.lesson-prose .callout > * + * { margin-top: 10px; }

.lesson-prose details {
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  background: var(--surface);
  padding: 0 16px;
}
.lesson-prose details details { margin-top: 10px; }
.lesson-prose details > summary { padding: 12px 0; cursor: pointer; font-weight: 600; line-height: 1.5; }
.lesson-prose details[open] > summary { border-bottom: 1px solid var(--border); margin-bottom: 14px; }
.lesson-prose details[open] { padding-bottom: 14px; }
.lesson-prose details > :not(summary) + * { margin-top: 14px; }

.lesson-prose .table-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius-s); }
.lesson-prose table { width: 100%; border-collapse: collapse; font-size: 15px; line-height: 1.5; }
.lesson-prose th, .lesson-prose td { padding: 10px 14px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--border); }
.lesson-prose th { background: var(--surface-2); font-weight: 600; white-space: nowrap; }
.lesson-prose tr:last-child td { border-bottom: 0; }
.lesson-prose td code { white-space: nowrap; }

/* ---------- Код ---------- */

.lesson-prose .code {
  position: relative;
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  background: var(--code-bg);
  color: var(--code-text);
  /* блок кода всегда тёмный, независимо от темы сайта */
  color-scheme: dark;
}
.lesson-prose .code pre {
  margin: 0;
  padding: 16px 18px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  tab-size: 4;
}
.lesson-prose .code code { font-family: inherit; }
.code-copy {
  position: absolute;
  top: 8px;
  right: 8px;
  min-height: 32px;
  padding: 4px 10px;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  background: var(--surface-2);
  color: var(--muted);
  font: inherit;
  font-size: 13px;
  cursor: pointer;
  opacity: 0;
  transition: opacity .15s;
}
.code:hover .code-copy, .code-copy:focus-visible { opacity: 1; }
@media (hover: none) { .code-copy { opacity: 1; } }
.code-copy:hover { color: var(--text); }

.code .c, .code .ch, .code .cm, .code .c1, .code .cs, .code .cp, .code .cpf { color: var(--code-comment); font-style: italic; }
.code .k, .code .kd, .code .kn, .code .kr, .code .ow, .code .nn { color: var(--code-keyword); }
.code .kc, .code .kp, .code .kt, .code .bp, .code .nb { color: var(--code-builtin); }
.code .s, .code .s1, .code .s2, .code .sb, .code .sc, .code .sd, .code .sh, .code .si, .code .sx, .code .dl, .code .sa { color: var(--code-string); }
.code .se, .code .sr { color: var(--code-number); }
.code .m, .code .mi, .code .mf, .code .mh, .code .mo, .code .mb, .code .il, .code .l { color: var(--code-number); }
.code .nf, .code .fm { color: var(--code-function); }
.code .nc, .code .ne, .code .no { color: var(--code-class); }
.code .nd, .code .nt, .code .na { color: var(--code-builtin); }
.code .gp, .code .go { color: #9a9aa3; }
.code .gd { color: #ff7b72; }
.code .gi { color: #7ee2a8; }
.code .gh, .code .gu { color: var(--code-function); font-weight: 600; }
.code .err { color: inherit; border: 0; }

/* ---------- Навигация между уроками ---------- */

.lesson-pager { display: grid; gap: 12px; margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--border); }
@media (min-width: 640px) { .lesson-pager { grid-template-columns: 1fr 1fr; } }
.lesson-pager__link {
  display: grid;
  gap: 4px;
  padding: 16px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  transition: border-color .15s;
}
.lesson-pager__link:hover { border-color: var(--accent-text); color: var(--text); }
.lesson-pager__link span { font-size: 13px; color: var(--muted); }
.lesson-pager__link b { font-weight: 600; line-height: 1.35; }
.lesson-pager__link--next { text-align: right; }
@media (min-width: 640px) { .lesson-pager__link--next { grid-column: 2; } }