/* Shared look of the learning pages: dark ground, one accent. Each
   training may override --accent only. */
:root {
  color-scheme: dark;
  --bg: #0b0f14;
  --panel: #121820;
  --panel-2: #192230;
  --line: #243040;
  --line-strong: #34465c;
  --text: #e8eef5;
  --muted: #8ea0b5;
  --dim: #5b6b7e;
  --accent: #2dd4bf;
  --accent-soft: rgba(45, 212, 191, 0.16);
  --green: #4ade80;
  --red: #f87171;
  --amber: #fbbf24;
  --radius: 12px;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --cyrillic: "Georgia", "Times New Roman", "Noto Serif", serif;
}

* { box-sizing: border-box; }
html { background: var(--bg); }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font: 16px/1.5 var(--sans);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
button {
  font: inherit;
  color: var(--text);
  background: var(--panel-2);
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  padding: 8px 14px;
  cursor: pointer;
}
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); color: #04221e; border-color: var(--accent); font-weight: 600; }
button.danger { border-color: var(--red); color: var(--red); }
button:disabled { opacity: 0.5; cursor: default; }
input[type="text"], select {
  font: inherit;
  color: var(--text);
  background: var(--panel-2);
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  padding: 8px 12px;
}
input[type="text"]:focus { outline: none; border-color: var(--accent); }

header.top {
  position: sticky; top: 0; z-index: 10;
  background: rgba(11, 15, 20, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  padding: 10px 16px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}
.brand { display: flex; align-items: baseline; gap: 10px; }
.brand .home { font-size: 1.1rem; color: var(--muted); }
.wordmark { font-weight: 700; letter-spacing: 0.02em; }
.wordmark em { font-style: normal; color: var(--accent); }
.version { font-family: var(--mono); font-size: 0.75rem; color: var(--dim); }
nav.tabs { display: flex; gap: 4px; flex-wrap: wrap; }
nav.tabs a {
  text-transform: uppercase; font-size: 0.78rem; letter-spacing: 0.08em;
  color: var(--muted); padding: 6px 10px; border-radius: 6px;
}
nav.tabs a.active, nav.tabs a:hover { color: var(--text); background: var(--panel-2); }

main { max-width: 960px; margin: 0 auto; padding: 24px 16px 64px; }
h1 { font-size: 1.5rem; margin: 0 0 8px; }
h2 { font-size: 1.1rem; margin: 24px 0 8px; }
p.lead, .muted { color: var(--muted); }
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; }
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
.mono { font-family: var(--mono); }
.small { font-size: 0.85rem; }

.progress { height: 6px; background: var(--panel-2); border-radius: 3px; overflow: hidden; display: flex; }
.progress > span { display: block; height: 100%; }
.progress .mastered { background: var(--accent); }
.progress .known { background: var(--green); }
.progress .learning { background: var(--amber); }

.card-list { display: grid; gap: 12px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.training-card { display: block; color: inherit; }
.training-card:hover { border-color: var(--accent); }
.training-card h3 { margin: 0 0 4px; }