/* Общие стили курса. Цвета — только через токены ниже, SVG тоже красим var(--…). */
:root {
  --bg: #fbfaf7;
  --bg-soft: #f2f0ea;
  --card: #ffffff;
  --text: #1d1f23;
  --muted: #5d6470;
  --border: #dedad0;
  --accent: #2f6fdd;
  --accent-soft: #e3ecfb;
  --ok: #1f8a4c;
  --ok-soft: #e1f3e8;
  --warn: #b86a00;
  --warn-soft: #fbefdc;
  --bad: #c43d3d;
  --bad-soft: #fae3e3;
  --violet: #7a4fd0;
  --violet-soft: #eee6fb;
  --teal: #11808a;
  --teal-soft: #ddf1f2;
  --code-bg: #f4f2ec;
  --code-text: #23262c;
  --shadow: 0 1px 2px rgba(0,0,0,.05), 0 4px 16px rgba(0,0,0,.04);
  --radius: 10px;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #15171b; --bg-soft: #1c1f24; --card: #1f2228; --text: #e6e7ea; --muted: #9aa1ad;
    --border: #33373f; --accent: #6ea1ff; --accent-soft: #1e2b44; --ok: #4cc584; --ok-soft: #173325;
    --warn: #f0a640; --warn-soft: #3a2b14; --bad: #ff7a7a; --bad-soft: #3d1d1d;
    --violet: #b394ff; --violet-soft: #2c2342; --teal: #4fc9d3; --teal-soft: #163538;
    --code-bg: #1a1d22; --code-text: #dfe2e7; --shadow: 0 1px 2px rgba(0,0,0,.4);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #15171b; --bg-soft: #1c1f24; --card: #1f2228; --text: #e6e7ea; --muted: #9aa1ad;
  --border: #33373f; --accent: #6ea1ff; --accent-soft: #1e2b44; --ok: #4cc584; --ok-soft: #173325;
  --warn: #f0a640; --warn-soft: #3a2b14; --bad: #ff7a7a; --bad-soft: #3d1d1d;
  --violet: #b394ff; --violet-soft: #2c2342; --teal: #4fc9d3; --teal-soft: #163538;
  --code-bg: #1a1d22; --code-text: #dfe2e7; --shadow: 0 1px 2px rgba(0,0,0,.4);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.65 var(--sans); -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-underline-offset: 2px; }
h1, h2, h3, h4 { line-height: 1.25; margin: 1.8em 0 .6em; }
h1 { font-size: 2rem; margin-top: .4em; }
h2 { font-size: 1.45rem; padding-top: .4em; border-top: 1px solid var(--border); }
h3 { font-size: 1.15rem; }
p, ul, ol { margin: .6em 0; }
li { margin: .25em 0; }
hr { border: 0; border-top: 1px solid var(--border); margin: 2em 0; }
small, .muted { color: var(--muted); }
kbd { font: 12px var(--mono); border: 1px solid var(--border); border-bottom-width: 2px; border-radius: 4px; padding: 1px 5px; }

/* ---------- Каркас ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 12px;
  padding: 10px 16px; background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px); border-bottom: 1px solid var(--border);
}
.topbar .brand { font-weight: 700; text-decoration: none; color: var(--text); white-space: nowrap; }
.topbar .spacer { flex: 1; }
.topbar .progress-mini { width: 120px; height: 6px; background: var(--bg-soft); border-radius: 3px; overflow: hidden; }
.topbar .progress-mini > i { display: block; height: 100%; background: var(--ok); width: 0; transition: width .3s; }
.btn {
  font: inherit; font-size: 14px; cursor: pointer; border: 1px solid var(--border); background: var(--card);
  color: var(--text); border-radius: 8px; padding: 6px 12px; line-height: 1.3;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn.ok { background: var(--ok); color: #fff; border-color: var(--ok); }
.btn:focus-visible, input:focus-visible, summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.layout { display: grid; grid-template-columns: 260px minmax(0, 1fr); max-width: 1320px; margin: 0 auto; }
.sidebar {
  position: sticky; top: 53px; align-self: start; height: calc(100vh - 53px); overflow: auto;
  padding: 20px 12px 40px 16px; border-right: 1px solid var(--border); font-size: 14px;
}
.sidebar h4 { margin: 1.2em 0 .4em; font-size: 12px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
.sidebar a { display: flex; gap: 8px; padding: 5px 8px; border-radius: 6px; color: var(--text); text-decoration: none; }
.sidebar a:hover { background: var(--bg-soft); }
.sidebar a.current { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.sidebar a .n { color: var(--muted); min-width: 1.6em; font-variant-numeric: tabular-nums; }
.sidebar a.done .n::after { content: " ✓"; color: var(--ok); }
.sidebar .toc a { padding: 3px 8px 3px 16px; color: var(--muted); font-size: 13px; }
.sidebar .toc a:hover { color: var(--text); }
main.content { padding: 24px 40px 80px; max-width: 920px; min-width: 0; }
.menu-btn { display: none; }

@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { display: none; position: fixed; inset: 53px 0 0 0; background: var(--bg); z-index: 15; height: auto; border: 0; }
  body.nav-open .sidebar { display: block; }
  .menu-btn { display: inline-block; }
  main.content { padding: 16px 16px 60px; }
  .topbar .progress-mini { display: none; }
}

/* ---------- Шапка модуля ---------- */
.module-hero { padding: 8px 0 12px; }
.module-hero .eyebrow { font-size: 13px; letter-spacing: .06em; text-transform: uppercase; color: var(--accent); font-weight: 600; }
.module-hero .lead { font-size: 1.1rem; color: var(--muted); max-width: 70ch; }
.meta-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.chip { font-size: 12.5px; padding: 3px 10px; border-radius: 999px; background: var(--bg-soft); border: 1px solid var(--border); color: var(--muted); }

/* ---------- Блоки контента ---------- */
.callout { border: 1px solid var(--border); border-left: 4px solid var(--accent); background: var(--accent-soft); padding: 12px 16px; border-radius: 8px; margin: 1.2em 0; }
.callout > :first-child { margin-top: 0; } .callout > :last-child { margin-bottom: 0; }
.callout.tip { border-left-color: var(--ok); background: var(--ok-soft); }
.callout.warn { border-left-color: var(--warn); background: var(--warn-soft); }
.callout.danger { border-left-color: var(--bad); background: var(--bad-soft); }
.callout.go { border-left-color: var(--teal); background: var(--teal-soft); }
.callout .title { font-weight: 700; display: block; margin-bottom: 4px; }

.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 18px; box-shadow: var(--shadow); }
.grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); margin: 1em 0; }
.grid .card h4 { margin: 0 0 .4em; }

table { border-collapse: collapse; width: 100%; margin: 1em 0; font-size: 14.5px; display: block; overflow-x: auto; }
th, td { border: 1px solid var(--border); padding: 7px 10px; text-align: left; vertical-align: top; }
th { background: var(--bg-soft); font-weight: 600; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }

p code, li code, td code { overflow-wrap: anywhere; }
code { font: .9em var(--mono); background: var(--code-bg); padding: .1em .35em; border-radius: 4px; }
pre { background: var(--code-bg); color: var(--code-text); border: 1px solid var(--border); border-radius: 8px; padding: 14px 16px; overflow-x: auto; font: 13.5px/1.55 var(--mono); position: relative; margin: 1em 0; tab-size: 4; }
pre code { background: none; padding: 0; font: inherit; }
pre .copy { position: absolute; top: 6px; right: 6px; font-size: 12px; padding: 2px 8px; opacity: 0; transition: opacity .15s; }
pre:hover .copy, pre .copy:focus { opacity: 1; }
/* Лёгкая подсветка, которую ставит course.js */
.tok-c { color: var(--muted); font-style: italic; }
.tok-s { color: var(--ok); }
.tok-k { color: var(--violet); font-weight: 600; }
.tok-n { color: var(--warn); }

/* Табы Go / Python */
.tabs { margin: 1em 0; }
.tabs .tab-bar { display: flex; flex-wrap: wrap; gap: 4px; border-bottom: 1px solid var(--border); }
.tabs .tab-bar button { font: inherit; font-size: 13.5px; background: none; border: 0; border-bottom: 2px solid transparent; padding: 6px 12px; cursor: pointer; color: var(--muted); }
.tabs .tab-bar button.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.tabs .tab-panel { display: none; } .tabs .tab-panel.active { display: block; }
.tabs .tab-panel pre { margin-top: 0; border-top-left-radius: 0; }

/* ---------- Визуализации ---------- */
.viz { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin: 1.4em 0; box-shadow: var(--shadow); }
.viz > .viz-title { font-weight: 700; margin: 0 0 4px; }
.viz > .viz-sub { color: var(--muted); font-size: 14px; margin: 0 0 12px; }
.viz svg { display: block; width: 100%; height: auto; max-width: 100%; }
.viz svg text { fill: var(--text); font-family: var(--sans); }
.viz .controls { display: flex; flex-wrap: wrap; gap: 14px 22px; align-items: center; margin: 10px 0; font-size: 14px; }
.viz .controls label { display: flex; align-items: center; gap: 8px; }
.viz .controls output { font: 13px var(--mono); min-width: 3.5em; color: var(--accent); }
.viz input[type=range] { accent-color: var(--accent); width: 160px; }
.viz textarea, .viz input[type=text], .viz select { font: 14px var(--mono); background: var(--bg-soft); color: var(--text); border: 1px solid var(--border); border-radius: 6px; padding: 6px 8px; width: 100%; }
.viz .legend { display: flex; flex-wrap: wrap; gap: 12px; font-size: 13px; color: var(--muted); }
.viz .legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; margin-right: 5px; vertical-align: middle; }
.viz .readout { font: 13px var(--mono); background: var(--bg-soft); border-radius: 6px; padding: 8px 10px; margin-top: 8px; white-space: pre-wrap; }

/* ---------- Задания, вопросы ---------- */
.task { border: 1px dashed var(--ok); border-radius: var(--radius); padding: 14px 18px; background: var(--ok-soft); margin: 1.2em 0; }
.task > h3:first-child, .task > h4:first-child { margin-top: 0; }
.task label.check { display: flex; gap: 8px; align-items: flex-start; cursor: pointer; }

details.q { border: 1px solid var(--border); border-radius: 8px; margin: 8px 0; background: var(--card); }
details.q > summary { cursor: pointer; padding: 10px 14px; font-weight: 600; list-style: none; }
details.q > summary::-webkit-details-marker { display: none; }
details.q > summary::before { content: "▸"; display: inline-block; width: 1.1em; color: var(--accent); transition: transform .15s; }
details.q[open] > summary::before { transform: rotate(90deg); }
details.q > .a { padding: 0 16px 12px 32px; border-top: 1px dashed var(--border); }
details.q.interview > summary::after { content: "собес"; font-size: 11px; font-weight: 600; margin-left: 8px; padding: 1px 7px; border-radius: 999px; background: var(--violet-soft); color: var(--violet); }

.module-footer { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-top: 48px; padding-top: 20px; border-top: 1px solid var(--border); }
.module-footer a { text-decoration: none; }
.done-toggle { margin: 32px 0 0; }

/* ---------- Главная ---------- */
.hero { padding: 24px 0 8px; }
.hero h1 { font-size: 2.4rem; margin: 0 0 .3em; }
.progress-big { height: 12px; background: var(--bg-soft); border: 1px solid var(--border); border-radius: 6px; overflow: hidden; margin: 8px 0 4px; }
.progress-big > i { display: block; height: 100%; background: var(--ok); width: 0; transition: width .4s; }
.module-list { display: grid; gap: 12px; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); margin: 1em 0; }
.module-list a.card { text-decoration: none; color: var(--text); display: block; transition: border-color .15s, transform .15s; }
.module-list a.card:hover { border-color: var(--accent); transform: translateY(-1px); }
.module-list .num { font: 600 13px var(--mono); color: var(--accent); }
.module-list h3 { margin: 4px 0 6px; font-size: 1.05rem; }
.module-list p { margin: 0; font-size: 14px; color: var(--muted); }
.module-list a.card.done { border-color: var(--ok); }
.module-list a.card.done .num::after { content: " · пройден ✓"; color: var(--ok); }

@media print { .topbar, .sidebar, .module-footer, .done-toggle { display: none; } .layout { display: block; } details.q > .a { display: block; } }
/* Выбор стека Go / Java */
.stack-switch { display: inline-flex; }
.stack-switch .btn { border-radius: 0; }
.stack-switch .btn:first-child { border-radius: 8px 0 0 8px; }
.stack-switch .btn:last-child { border-radius: 0 8px 8px 0; margin-left: -1px; }
.stack-switch .btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }
html:not([data-stack=java]) [data-only=java], html[data-stack=java] [data-only=go] { display: none !important; }