/* =========================================================
   Paper Theme — scoped дизайн-система GTM Hub.
   Активируется добавлением класса .paper-theme на корне страницы.
   Старые editorial-страницы остаются нетронутыми.
   ========================================================= */

.paper-theme {
  --paper: #FAF7F2;
  --paper-2: #F2EDE3;
  --paper-3: #E8E1D2;
  --line: #E5DFD3;
  --line-2: #D3CAB6;
  --ink: #0F0F10;
  --ink-2: #1F1E1C;
  --ink-3: #5C5852;
  --ink-4: #8C8478;
  --accent: #D03A1F;
  --accent-soft: #F4D9D2;
  --hi: #F2D26B;
  --ok: #3F7A4A;
  --sans: 'Geist', 'Inter', system-ui, -apple-system, sans-serif;
  --serif: 'Source Serif 4', Georgia, serif;
  --mono: 'JetBrains Mono', ui-monospace, monospace;
  --r-1: 4px;
  --r-2: 8px;
  --r-3: 12px;
  --r-4: 18px;

  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

.paper-theme * { box-sizing: border-box; }
.paper-theme a { color: inherit; text-decoration: none; }
.paper-theme button { font-family: inherit; }

/* === stage / wrapper === */
.paper-theme .stage { max-width: 1320px; margin: 0 auto; padding: 32px; }
.paper-theme .stage-head { display: flex; align-items: flex-start; justify-content: space-between; margin-bottom: 24px; flex-wrap: wrap; gap: 16px; }
.paper-theme .stage-head > div:first-child { display: flex; flex-direction: column; gap: 8px; flex: 1; min-width: 320px; }
.paper-theme .stage-h1 { font-family: var(--serif); font-size: 42px; line-height: 1; letter-spacing: -.02em; font-weight: 500; margin: 0; }
.paper-theme .stage-h1 em { font-style: italic; color: var(--accent); }
.paper-theme .stage-sub { color: var(--ink-3); font-size: 14px; max-width: 520px; margin: 6px 0 0; }

/* === crumb (breadcrumb mono) === */
.paper-theme .crumb { font-family: var(--mono); font-size: 11px; color: var(--ink-4); text-transform: uppercase; letter-spacing: .08em; display: flex; gap: 8px; align-items: center; margin-bottom: 8px; flex-wrap: wrap; }
.paper-theme .crumb .sep { opacity: .4; }
.paper-theme .crumb .accent { color: var(--accent); }

/* === buttons === */
.paper-theme .btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 14px; border-radius: 8px; border: 1px solid var(--line-2); background: var(--paper); font-size: 13px; font-weight: 500; cursor: pointer; color: var(--ink); text-decoration: none; letter-spacing: -.005em; transition: background .12s; }
.paper-theme .btn:hover { background: var(--paper-2); }
.paper-theme .btn.primary { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.paper-theme .btn.primary:hover { background: var(--ink-2); }
.paper-theme .btn.accent { background: var(--accent); color: var(--paper); border-color: var(--accent); }
.paper-theme .btn.lg { padding: 12px 20px; font-size: 14px; border-radius: 10px; }
.paper-theme .btn.sm { padding: 5px 9px; font-size: 12px; border-radius: 6px; }
.paper-theme .btn.ghost { border-color: transparent; background: transparent; color: var(--ink-3); }
.paper-theme .btn.ghost:hover { background: var(--paper-2); color: var(--ink); }

/* === tags === */
.paper-theme .tag { display: inline-flex; align-items: center; gap: 4px; font-family: var(--mono); font-size: 10px; padding: 2px 7px; border-radius: 4px; background: var(--paper-2); color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; font-weight: 500; border: 1px solid var(--line); }
.paper-theme .tag.solid { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.paper-theme .tag.accent { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.paper-theme .tag.ok { background: #E1ECDF; color: var(--ok); border-color: transparent; }
.paper-theme .tag.dot::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; display: inline-block; }

/* === card primitives === */
.paper-theme .card { background: var(--paper); border: 1px solid var(--line); border-radius: var(--r-3); padding: 20px; }
.paper-theme .card.tight { padding: 14px; }
.paper-theme .card .label { font-family: var(--mono); font-size: 10px; color: var(--ink-4); text-transform: uppercase; letter-spacing: .08em; font-weight: 500; }
.paper-theme .divider { height: 1px; background: var(--line); border: 0; margin: 14px 0; }

.paper-theme .row { display: flex; }
.paper-theme .col { display: flex; flex-direction: column; }
.paper-theme .gap-1 { gap: 4px; }
.paper-theme .gap-2 { gap: 8px; }
.paper-theme .gap-3 { gap: 12px; }
.paper-theme .gap-4 { gap: 16px; }
.paper-theme .gap-5 { gap: 20px; }
.paper-theme .gap-6 { gap: 24px; }
.paper-theme .gap-8 { gap: 32px; }
.paper-theme .flex-1 { flex: 1; }
.paper-theme .center { align-items: center; justify-content: center; }
.paper-theme .between { justify-content: space-between; }
.paper-theme .wrap { flex-wrap: wrap; }
.paper-theme .start { align-items: flex-start; }
.paper-theme .muted { color: var(--ink-3); }
.paper-theme .tiny { font-size: 11px; }
.paper-theme .mono { font-family: var(--mono); }
.paper-theme .serif { font-family: var(--serif); }

/* === book spread === */
.paper-theme .spread {
  display: grid;
  grid-template-columns: 1fr 1fr;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--r-4);
  overflow: hidden;
  position: relative;
  box-shadow: 0 1px 0 var(--line), 0 24px 60px -30px rgba(15, 15, 16, .18);
}
.paper-theme .spread::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--line);
  transform: translateX(-.5px);
  pointer-events: none;
}
.paper-theme .spread::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 24px;
  transform: translateX(-50%);
  background: linear-gradient(90deg, rgba(15, 15, 16, 0) 0%, rgba(15, 15, 16, .04) 50%, rgba(15, 15, 16, 0) 100%);
  pointer-events: none;
}
.paper-theme .page { padding: 48px 56px; min-height: 680px; display: flex; flex-direction: column; }
.paper-theme .page.left { padding-right: 48px; }
.paper-theme .page.right { padding-left: 48px; }

.paper-theme .folio { font-family: var(--mono); font-size: 10px; color: var(--ink-4); text-transform: uppercase; letter-spacing: .12em; display: flex; justify-content: space-between; margin-bottom: 24px; }
.paper-theme .chapter-num { font-family: var(--serif); font-style: italic; font-size: 14px; color: var(--accent); margin-bottom: 8px; letter-spacing: .02em; }
.paper-theme .chapter-title { font-family: var(--serif); font-size: 36px; line-height: 1.05; letter-spacing: -.015em; font-weight: 500; margin: 0 0 8px; color: var(--ink); }
.paper-theme .lede { font-family: var(--serif); font-size: 18px; line-height: 1.5; color: var(--ink-2); margin: 12px 0 20px; font-weight: 400; }

/* body content (rendered markdown HTML) */
.paper-theme .body { color: var(--ink-2); }
.paper-theme .body p { font-size: 14.5px; line-height: 1.7; color: var(--ink-2); margin: 0 0 12px; text-wrap: pretty; }
.paper-theme .body h1, .paper-theme .body h2, .paper-theme .body h3 { font-family: var(--serif); font-weight: 500; letter-spacing: -.01em; color: var(--ink); margin: 24px 0 10px; }
.paper-theme .body h1 { font-size: 28px; line-height: 1.1; }
.paper-theme .body h2 { font-size: 22px; line-height: 1.15; }
.paper-theme .body h3 { font-size: 17px; line-height: 1.25; }
.paper-theme .body ul, .paper-theme .body ol { margin: 0 0 14px; padding-left: 22px; font-size: 14.5px; line-height: 1.7; color: var(--ink-2); }
.paper-theme .body li { margin-bottom: 4px; }
.paper-theme .body a { color: var(--accent); text-decoration: underline; text-decoration-color: var(--accent-soft); text-underline-offset: 2px; }
.paper-theme .body a:hover { text-decoration-color: var(--accent); }
.paper-theme .body code { font-family: var(--mono); font-size: 12.5px; background: var(--paper-2); padding: 1px 5px; border-radius: 3px; }
.paper-theme .body pre { font-family: var(--mono); font-size: 12px; background: #0F0F10; color: #E5DFD3; padding: 14px 18px; border-radius: var(--r-2); line-height: 1.6; overflow-x: auto; margin: 16px 0; }
.paper-theme .body pre code { background: transparent; padding: 0; color: inherit; }
.paper-theme .body blockquote { border-left: 2px solid var(--accent); padding: 4px 0 4px 14px; font-style: italic; color: var(--ink-2); margin: 14px 0; font-family: var(--serif); }
.paper-theme .body table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 13px; }
.paper-theme .body th, .paper-theme .body td { border: 1px solid var(--line); padding: 8px 12px; text-align: left; }
.paper-theme .body th { background: var(--paper-2); font-weight: 600; }
.paper-theme .body hr { border: 0; border-top: 1px solid var(--line); margin: 24px 0; }
.paper-theme .body img { max-width: 100%; border-radius: var(--r-2); border: 1px solid var(--line); }

.paper-theme .dropcap > p:first-of-type::first-letter { font-family: var(--serif); font-size: 54px; float: left; line-height: .85; margin: 6px 8px 0 0; font-weight: 600; color: var(--accent); }

.paper-theme .marginal { border-left: 2px solid var(--accent); padding: 4px 0 4px 12px; font-family: var(--serif); font-style: italic; font-size: 14px; color: var(--ink-2); margin: 14px 0; line-height: 1.5; }
.paper-theme .marginal .src { display: block; font-family: var(--mono); font-style: normal; font-size: 10px; color: var(--ink-4); margin-top: 6px; letter-spacing: .06em; text-transform: uppercase; }

.paper-theme .section-h { font-family: var(--sans); font-size: 11px; text-transform: uppercase; letter-spacing: .12em; color: var(--ink-4); font-weight: 600; margin: 20px 0 10px; }

/* === diagram (mermaid wrapper) === */
.paper-theme .diagram { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--r-2); padding: 18px; position: relative; }
.paper-theme .diagram-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.paper-theme .diagram-head .lbl { font-family: var(--mono); font-size: 10px; text-transform: uppercase; letter-spacing: .1em; color: var(--ink-4); font-weight: 500; }
.paper-theme .mermaid { font-family: var(--mono) !important; }
.paper-theme .mermaid svg { max-width: 100% !important; height: auto !important; }
.paper-theme .mermaid .label, .paper-theme .mermaid .nodeLabel { font-family: var(--sans) !important; font-size: 13px !important; }
.paper-theme .mermaid .edgeLabel { background: var(--paper) !important; font-family: var(--mono) !important; font-size: 11px !important; color: var(--ink-3) !important; }

/* === video block === */
.paper-theme .video { aspect-ratio: 16/9; background: #0a0a0a; border-radius: var(--r-2); position: relative; overflow: hidden; cursor: pointer; border: 1px solid var(--ink); margin: 8px 0 20px; }
.paper-theme .video::before { content: ""; position: absolute; inset: 0; background: radial-gradient(ellipse at 30% 30%, rgba(208, 58, 31, .18), transparent 60%), linear-gradient(135deg, #1a1a1a, #0a0a0a); }
.paper-theme .video::after { content: ""; position: absolute; inset: 8px; border: 1px solid rgba(255, 255, 255, .06); border-radius: 6px; pointer-events: none; }
.paper-theme .play { position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); width: 64px; height: 64px; border-radius: 50%; background: var(--accent); display: grid; place-items: center; color: var(--paper); box-shadow: 0 8px 32px rgba(208, 58, 31, .4); border: 0; cursor: pointer; }
.paper-theme .play svg { width: 22px; height: 22px; margin-left: 3px; }
.paper-theme .video .meta { position: absolute; left: 14px; bottom: 14px; color: #fff; font-family: var(--mono); font-size: 11px; letter-spacing: .06em; text-transform: uppercase; opacity: .85; }
.paper-theme .video .chapt { position: absolute; left: 14px; top: 14px; color: #fff; font-family: var(--mono); font-size: 10px; letter-spacing: .1em; text-transform: uppercase; opacity: .5; }

/* === skill rail (sidebar) === */
.paper-theme .rail { position: sticky; top: 80px; }
.paper-theme .rail-head { font-family: var(--mono); font-size: 10px; text-transform: uppercase; letter-spacing: .1em; color: var(--ink-4); font-weight: 500; margin-bottom: 10px; }
.paper-theme .tier { margin-bottom: 14px; }
.paper-theme .tier-h { display: flex; align-items: baseline; gap: 8px; margin-bottom: 6px; padding-bottom: 6px; border-bottom: 1px solid var(--line); }
.paper-theme .tier-h .n { font-family: var(--mono); font-size: 10px; color: var(--ink-4); }
.paper-theme .tier-h .name { font-size: 11.5px; font-weight: 600; letter-spacing: -.005em; }
.paper-theme .tier-h .meta { margin-left: auto; font-family: var(--mono); font-size: 10px; color: var(--ink-4); }
.paper-theme .lesson-row { display: flex; align-items: center; gap: 8px; padding: 5px 6px; border-radius: 6px; font-size: 12px; color: var(--ink-3); cursor: pointer; line-height: 1.3; text-decoration: none; }
.paper-theme .lesson-row:hover { background: var(--paper-2); color: var(--ink); }
.paper-theme .lesson-row.active { background: var(--accent-soft); color: var(--accent); font-weight: 500; }
.paper-theme .lesson-row.done { color: var(--ink-4); text-decoration: line-through; text-decoration-thickness: 1px; text-decoration-color: var(--line-2); }
.paper-theme .lesson-row .id { font-family: var(--mono); font-size: 10px; width: 32px; flex-shrink: 0; opacity: .7; }
.paper-theme .lesson-row .ic { width: 14px; height: 14px; border-radius: 50%; border: 1.5px solid var(--line-2); flex-shrink: 0; display: grid; place-items: center; }
.paper-theme .lesson-row.done .ic { background: var(--ink); border-color: var(--ink); }
.paper-theme .lesson-row.done .ic::after { content: "✓"; color: var(--paper); font-size: 9px; font-weight: 700; }
.paper-theme .lesson-row.active .ic { background: var(--accent); border-color: var(--accent); }
.paper-theme .lesson-row.active .ic::after { content: ""; width: 5px; height: 5px; background: var(--paper); border-radius: 50%; }
.paper-theme .lesson-row .ttl { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.paper-theme .lesson-row .v { color: var(--accent); font-size: 9px; }
.paper-theme .lesson-row.locked { opacity: .5; cursor: default; }
.paper-theme .lesson-row.locked:hover { background: transparent; color: var(--ink-3); }

/* === main two-column layout (rail + content) === */
.paper-theme .layout { display: grid; grid-template-columns: 240px 1fr; gap: 32px; align-items: flex-start; max-width: 1320px; margin: 0 auto; padding: 32px; }
@media (max-width: 1100px) {
  .paper-theme .layout { grid-template-columns: 1fr; padding: 20px; }
  .paper-theme .rail { position: static; }
}
@media (max-width: 900px) {
  .paper-theme .spread { grid-template-columns: 1fr; }
  .paper-theme .spread::before { display: none; }
  .paper-theme .spread::after { display: none; }
  .paper-theme .page { padding: 32px 24px; min-height: 0; }
  .paper-theme .page.left { padding-right: 24px; }
  .paper-theme .page.right { padding-left: 24px; }
}

/* === relation rail (prerequisites / unlocks) === */
.paper-theme .rel { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 14px; }
@media (max-width: 720px) { .paper-theme .rel { grid-template-columns: 1fr; } }
.paper-theme .rel-side { padding: 14px; border: 1px solid var(--line); border-radius: var(--r-2); background: var(--paper-2); }
.paper-theme .rel-side .lbl { font-family: var(--mono); font-size: 10px; text-transform: uppercase; letter-spacing: .1em; color: var(--ink-4); margin-bottom: 6px; }
.paper-theme .rel-side a { display: flex; justify-content: space-between; align-items: center; padding: 6px 0; border-bottom: 1px dashed var(--line); font-size: 13px; color: var(--ink-2); text-decoration: none; gap: 8px; }
.paper-theme .rel-side a:last-child { border-bottom: 0; }
.paper-theme .rel-side a .id { font-family: var(--mono); font-size: 11px; color: var(--ink-4); }
.paper-theme .rel-side a:hover { color: var(--accent); }
.paper-theme .rel-side .arrow { color: var(--accent); }
.paper-theme .rel-side .empty { font-size: 12px; color: var(--ink-4); font-style: italic; padding: 6px 0; }

/* === reading progress bar (top) === */
.paper-theme .reading-progress { position: fixed; top: 0; left: 0; right: 0; height: 2px; background: transparent; z-index: 100; pointer-events: none; }
.paper-theme .reading-progress span { display: block; height: 100%; width: 0; background: var(--accent); transition: width .1s ease-out; }

/* === lesson page (full-width article card) === */
.paper-theme .lesson-page {
  margin: 0;
  padding: 56px 80px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--r-4);
  box-shadow: 0 1px 0 var(--line), 0 24px 60px -30px rgba(15, 15, 16, .12);
  position: relative;
}
@media (max-width: 720px) {
  .paper-theme .lesson-page { padding: 32px 22px; border-radius: var(--r-2); }
}

.paper-theme .lesson-outro { margin-top: 32px; padding-top: 24px; border-top: 1px solid var(--line); }
.paper-theme .lesson-outro .takeaways { list-style: none; padding: 0; margin: 0 0 24px; counter-reset: tk; }
.paper-theme .lesson-outro .takeaways li { position: relative; padding-left: 28px; margin-bottom: 10px; font-size: 14.5px; line-height: 1.55; color: var(--ink-2); counter-increment: tk; }
.paper-theme .lesson-outro .takeaways li::before { content: counter(tk); position: absolute; left: 0; top: 0; font-family: var(--mono); font-size: 11px; color: var(--accent); font-weight: 500; line-height: 1.6; letter-spacing: .04em; }

.paper-theme .lesson-outro .cliff { background: var(--paper-2); border: 1px solid var(--accent-soft); border-radius: var(--r-3); padding: 24px 28px; margin: 24px 0; }
.paper-theme .lesson-outro .cliff .icon { font-size: 28px; margin-bottom: 6px; }
.paper-theme .lesson-outro .cliff h3 { font-family: var(--serif); font-size: 22px; font-weight: 500; letter-spacing: -.01em; margin: 0 0 8px; color: var(--ink); }
.paper-theme .lesson-outro .cliff p { font-size: 14px; line-height: 1.6; color: var(--ink-2); margin: 0 0 14px; }

.paper-theme .lesson-outro .actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 20px; }

/* === paywall banner (floating, bottom-left "flying" card) === */
.paper-theme .paywall-banner {
  position: fixed; left: 24px; bottom: 24px; right: auto; z-index: 60;
  width: 320px; max-width: calc(100vw - 32px);
  background: var(--paper); border: 1px solid var(--line-2);
  border-radius: var(--r-4);
  box-shadow: 0 18px 48px -16px rgba(15, 15, 16, .35), 0 2px 8px -4px rgba(15, 15, 16, .2);
  padding: 18px 20px;
  display: flex; flex-direction: column; gap: 12px; align-items: stretch;
  animation: pw-appear .45s cubic-bezier(.2, .8, .2, 1) both, pw-float 5s ease-in-out .6s infinite;
}
@keyframes pw-appear {
  from { opacity: 0; transform: translateY(28px) scale(.96); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes pw-float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}
.paper-theme .paywall-banner:hover { animation-play-state: paused; }
.paper-theme .paywall-banner .pw-badge {
  display: inline-flex; align-items: center; gap: 5px; align-self: flex-start;
  font-family: var(--mono); font-size: 10px; font-weight: 500; text-transform: uppercase; letter-spacing: .07em;
  color: var(--accent); background: var(--accent-soft); border-radius: 999px; padding: 3px 9px;
}
.paper-theme .paywall-banner .pw-text { display: flex; flex-direction: column; gap: 3px; }
.paper-theme .paywall-banner .pw-title { font-family: var(--serif); font-size: 17px; font-weight: 500; color: var(--ink); letter-spacing: -.01em; }
.paper-theme .paywall-banner .pw-sub { font-size: 12.5px; line-height: 1.5; color: var(--ink-3); }
.paper-theme .paywall-banner .pw-cta { display: flex; flex-direction: column; gap: 8px; margin-top: 2px; }
.paper-theme .paywall-banner .pw-cta .btn { width: 100%; justify-content: center; }
@media (max-width: 720px) {
  .paper-theme .paywall-banner { left: 16px; right: 16px; bottom: 16px; width: auto; }
}
@media (prefers-reduced-motion: reduce) {
  .paper-theme .paywall-banner { animation: pw-appear .3s ease-out both; }
}

/* =========================================================
   Theme toggle (rail) — sun/moon button.
   ========================================================= */
.paper-theme .rail-theme {
  display: flex; align-items: center; gap: 8px;
  width: 100%; margin-bottom: 18px;
  padding: 8px 10px; border-radius: var(--r-2);
  border: 1px solid var(--line-2); background: var(--paper-2);
  color: var(--ink-3); font-family: var(--sans); font-size: 12px; font-weight: 500;
  cursor: pointer; transition: background .12s, color .12s, border-color .12s;
}
.paper-theme .rail-theme:hover { background: var(--paper-3); color: var(--ink); }
.paper-theme .rail-theme .icon { flex-shrink: 0; }
.paper-theme .rail-theme .label { flex: 1; text-align: left; }
/* show moon in light mode (offers dark), sun in dark mode (offers light) */
.paper-theme .rail-theme .icon-sun { display: none; }
.paper-theme .rail-theme[data-theme="dark"] .icon-moon { display: none; }
.paper-theme .rail-theme[data-theme="dark"] .icon-sun { display: inline; }

/* =========================================================
   Dark theme — activated by <html data-theme="dark">.
   Warm, low-glare editorial palette for comfortable night reading.
   Only the design-system variables flip; everything else inherits.
   ========================================================= */
[data-theme="dark"] .paper-theme {
  --paper:       #16140F;
  --paper-2:     #1F1C15;
  --paper-3:     #2A261D;
  --line:        #322D23;
  --line-2:      #443D30;
  --ink:         #F1ECE2;
  --ink-2:       #DBD4C6;
  --ink-3:       #A69D8D;
  --ink-4:       #7B7363;
  --accent:      #FF6A4D;
  --accent-soft: #3A211B;
  --hi:          #E7C25C;
  --ok:          #6FB07C;
  color-scheme: dark;
}

/* smooth cross-fade when toggling */
.paper-theme { transition: background-color .25s ease, color .25s ease; }

/* fixups for hardcoded (non-variable) colors in dark */
[data-theme="dark"] .paper-theme .tag.ok { background: #1E2A22; }
[data-theme="dark"] .paper-theme .body pre {
  background: #0C0B08; color: #E5DFD3; border: 1px solid var(--line);
}
[data-theme="dark"] .paper-theme .spread::after {
  background: linear-gradient(90deg, rgba(255, 255, 255, 0) 0%, rgba(255, 255, 255, .05) 50%, rgba(255, 255, 255, 0) 100%);
}