/* ============================================================
   Agentic AI for Trading — Study Companion
   Quant-research-desk system:
   paper  #EEF1F4  cool exchange-floor gray
   panel  #FFFFFF
   ink    #0E1B2C  midnight navy
   ink2   #55637A  slate
   long   #0B7A48  market green  → public / verified / complete
   short  #B8382F  market red    → material not found / paywalled
   amber  #A15C07  assessments
   line   #D6DCE4
   Type: Barlow Condensed (display) · Source Serif 4 (body)
         IBM Plex Mono (data/labels)
   ============================================================ */

:root {
  --paper: #EEF1F4;
  --panel: #FFFFFF;
  --ink: #0E1B2C;
  --ink2: #55637A;
  --long: #0B7A48;
  --long-soft: #E2F1E9;
  --short: #B8382F;
  --short-soft: #F9E9E7;
  --amber: #A15C07;
  --amber-soft: #F6EDDE;
  --line: #D6DCE4;
  --line-soft: #E4E8EE;
  --wire: #9FB0C4;
  --display: "Barlow Condensed", "Arial Narrow", sans-serif;
  --body: "Source Serif 4", Georgia, "Times New Roman", serif;
  --mono: "IBM Plex Mono", "SF Mono", Menlo, Consolas, monospace;
  --rail-w: 304px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--body);
  font-size: 16.5px;
  line-height: 1.62;
  color: var(--ink);
  background: var(--paper);
}

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
  border-radius: 2px;
}

::selection { background: #CFE3D9; }

/* ------------------------------------------------ layout */

.rail {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--rail-w);
  background: var(--panel);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  z-index: 40;
}

.main {
  margin-left: var(--rail-w);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.content {
  width: 100%;
  max-width: 920px;
  margin: 0 auto;
  padding: 0 44px 96px;
  flex: 1;
}

/* ------------------------------------------------ rail */

.rail-brand {
  padding: 22px 22px 18px;
  border-bottom: 1px solid var(--line);
}

.rail-brand a {
  text-decoration: none;
  display: block;
}

.rail-kicker {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink2);
  margin-bottom: 6px;
}

.rail-title {
  font-family: var(--display);
  font-weight: 700;
  font-size: 27px;
  line-height: 1.02;
  text-transform: uppercase;
  letter-spacing: 0.01em;
}

.rail-progress {
  padding: 14px 22px;
  border-bottom: 1px solid var(--line);
}

.rail-progress-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink2);
  margin-bottom: 7px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.rail-progress-row strong { color: var(--long); font-weight: 500; }

.meter {
  height: 4px;
  background: var(--line-soft);
  border-radius: 2px;
  overflow: hidden;
}

.meter > span {
  display: block;
  height: 100%;
  background: var(--long);
  border-radius: 2px;
  transition: width .45s ease;
}

.rail-search { padding: 12px 22px; border-bottom: 1px solid var(--line); }

.rail-search input {
  width: 100%;
  font-family: var(--mono);
  font-size: 12.5px;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--paper);
  color: var(--ink);
}
.rail-search input::placeholder { color: var(--ink2); }
.rail-search input:focus { outline: 2px solid var(--ink); outline-offset: 1px; }

.rail-nav {
  overflow-y: auto;
  flex: 1;
  padding: 10px 0 24px;
}

.rail-nav a {
  display: grid;
  grid-template-columns: 34px 1fr auto;
  gap: 0 10px;
  align-items: baseline;
  padding: 7px 22px 7px 18px;
  text-decoration: none;
  border-left: 4px solid transparent;
  font-family: var(--display);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.015em;
  line-height: 1.25;
  color: var(--ink);
}

.rail-nav a .no {
  font-family: var(--mono);
  font-size: 10.5px;
  font-weight: 400;
  color: var(--ink2);
}

.rail-nav a .tick {
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--ink2);
}
.rail-nav a .tick.done { color: var(--long); }

.rail-nav a:hover { background: var(--paper); }
.rail-nav a.active {
  border-left-color: var(--long);
  background: var(--long-soft);
}

.rail-foot {
  padding: 14px 22px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 10px;
  line-height: 1.6;
  color: var(--ink2);
  letter-spacing: 0.03em;
}
.rail-foot a { color: var(--ink2); }

/* mobile top bar */
.topbar {
  display: none;
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  padding: 12px 18px;
  align-items: center;
  gap: 14px;
}

.topbar button {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: var(--ink);
  color: #fff;
  border: 0;
  padding: 8px 13px;
  border-radius: 4px;
  cursor: pointer;
}

.topbar .topbar-title {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: 19px;
}

.scrim {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(14, 27, 44, 0.45);
  z-index: 35;
  border: 0;
}

/* ------------------------------------------------ tape */

.tape {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink2);
  border-bottom: 1px solid var(--line);
  padding: 10px 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tape b { color: var(--long); font-weight: 500; }

/* ------------------------------------------------ hero */

.hero { padding: 58px 0 12px; }

.eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--long);
  margin-bottom: 14px;
}

.hero h1 {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: clamp(52px, 8vw, 96px);
  line-height: 0.94;
  letter-spacing: 0.005em;
  max-width: 11ch;
}

.hero .lede {
  max-width: 60ch;
  margin-top: 22px;
  font-size: 18.5px;
  color: var(--ink);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 24px;
}

.chip {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 6px 11px;
  border-radius: 3px;
  color: var(--ink2);
}

.chip.solid { background: var(--ink); border-color: var(--ink); color: #fff; }
.chip a { color: inherit; text-decoration: none; }

/* ------------------------------------------------ honesty note */

.honesty {
  margin: 40px 0 0;
  border: 1px solid var(--line);
  border-left: 4px solid var(--ink);
  background: var(--panel);
  padding: 18px 22px;
  font-size: 15px;
}

.honesty h2 {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.honesty p { color: var(--ink2); max-width: 72ch; }
.honesty p + p { margin-top: 8px; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.05em;
}

.legend .dot {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  margin-right: 6px;
  vertical-align: 1px;
}
.dot.g { background: var(--long); }
.dot.r { background: var(--short); }
.dot.a { background: var(--amber); }

/* ------------------------------------------------ pipeline (signature) */

.pipeline-wrap { margin: 56px 0 0; }

.section-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink2);
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.section-label::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line);
}

.pipeline {
  display: flex;
  align-items: stretch;
  gap: 0;
  overflow-x: auto;
  padding: 10px 2px 18px;
  position: relative;
}

.pl-node {
  position: relative;
  z-index: 1;
  flex: 1 1 140px;
  min-width: 138px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 14px 14px 12px;
  text-decoration: none;
  transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease;
}

.pl-node:hover {
  transform: translateY(-3px);
  border-color: var(--ink);
  box-shadow: 0 8px 18px rgba(14, 27, 44, 0.10);
}

.pl-node .pl-n {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--long);
  margin-bottom: 6px;
}

.pl-node .pl-name {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: 19px;
  line-height: 1.05;
}

.pl-node .pl-job {
  margin-top: 7px;
  font-size: 12.5px;
  line-height: 1.45;
  color: var(--ink2);
}

.pl-wire {
  flex: 0 0 24px;
  min-width: 24px;
  position: relative;
  align-self: center;
  height: 2px;
  background: var(--wire);
}

.pl-wire::after {
  content: "";
  position: absolute;
  right: -1px;
  top: -3px;
  border-left: 6px solid var(--wire);
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
}

.pl-pulse {
  position: absolute;
  z-index: 0;
  top: 50%;
  left: 0;
  width: 8px;
  height: 8px;
  margin-top: -4px;
  border-radius: 50%;
  background: var(--long);
  box-shadow: 0 0 0 4px rgba(11, 122, 72, 0.15);
  animation: pulse-run 7s linear infinite;
  pointer-events: none;
}

@keyframes pulse-run {
  0%   { left: 0%;   opacity: 0; }
  4%   { opacity: 1; }
  96%  { opacity: 1; }
  100% { left: 100%; opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .pl-pulse { display: none; }
}

.pipeline-caption {
  font-size: 13.5px;
  color: var(--ink2);
  max-width: 68ch;
}

/* ------------------------------------------------ skills */

.skills {
  margin-top: 56px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.skill-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 18px 20px;
}

.skill-card h3 {
  font-family: var(--display);
  text-transform: uppercase;
  font-weight: 700;
  font-size: 19px;
  margin-bottom: 10px;
}

.skill-card li {
  list-style: none;
  font-size: 14px;
  color: var(--ink2);
  padding: 4px 0 4px 16px;
  position: relative;
}

.skill-card li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--long);
  font-size: 11px;
  top: 7px;
}

/* ------------------------------------------------ syllabus grid (home) */

.syllabus-grid {
  margin-top: 18px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.sy-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 16px 18px 14px;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color .15s ease, transform .15s ease;
}

.sy-card:hover { border-color: var(--ink); transform: translateY(-2px); }

.sy-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--ink2);
  letter-spacing: 0.08em;
}

.sy-top .free { color: var(--long); }

.sy-card h3 {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: 21px;
  line-height: 1.05;
}

.sy-stats {
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--ink2);
  letter-spacing: 0.05em;
  display: flex;
  justify-content: space-between;
  gap: 8px;
}

.sy-card .meter { margin-top: 2px; }

/* ------------------------------------------------ section view */

.crumb {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink2);
  padding-top: 34px;
}
.crumb a { color: var(--ink2); text-decoration: none; }
.crumb a:hover { color: var(--ink); text-decoration: underline; }

.sec-head { padding: 18px 0 8px; }

.sec-no {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--long);
  margin-bottom: 10px;
}

.sec-head h1 {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: clamp(38px, 5.4vw, 60px);
  line-height: 0.97;
  max-width: 18ch;
}

.sec-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

/* availability banner */
.avail {
  margin-top: 26px;
  border-radius: 6px;
  padding: 14px 18px;
  font-size: 14.5px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
  border: 1px solid;
}

.avail .avail-icon {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  padding: 3px 8px;
  border-radius: 3px;
  white-space: nowrap;
  margin-top: 1px;
}

.avail.ok { background: var(--long-soft); border-color: #BCDCCB; }
.avail.ok .avail-icon { background: var(--long); color: #fff; }
.avail.no { background: var(--short-soft); border-color: #E7C2BE; }
.avail.no .avail-icon { background: var(--short); color: #fff; }
.avail p { color: var(--ink); max-width: 70ch; }
.avail a { color: inherit; }

/* primer */
.primer {
  margin-top: 34px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 26px 30px 28px;
}

.primer-tag {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink2);
  margin-bottom: 14px;
  display: flex;
  gap: 10px;
  align-items: center;
}

.primer-tag::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--long);
}

.primer .primer-body { font-size: 16.5px; max-width: 72ch; }
.primer .primer-body p + p { margin-top: 12px; }

.primer .not-found {
  color: var(--short);
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.7;
}

.concepts {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 18px;
}

.concepts span {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.03em;
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 5px 10px;
  border-radius: 999px;
  color: var(--ink2);
}

/* ------------------------------------------------ unit table */

.units { margin-top: 40px; }

.unit-row {
  display: grid;
  grid-template-columns: 30px 68px 1fr auto;
  gap: 0 14px;
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 0;
  padding: 10px 16px 10px 12px;
}

.unit-row:first-of-type {
  border-top: 1px solid var(--line);
  border-radius: 6px 6px 0 0;
}
.unit-row:last-of-type { border-radius: 0 0 6px 6px; }

.unit-row.done { background: #F7FBF9; }
.unit-row.done .u-title { color: var(--ink2); }

.u-check {
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--wire);
  border-radius: 4px;
  background: var(--panel);
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
  padding: 0;
}

.u-check[aria-checked="true"] {
  background: var(--long);
  border-color: var(--long);
}

.u-check[aria-checked="true"]::after {
  content: "✓";
  color: #fff;
  font-size: 12px;
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.u-type {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-align: center;
  padding: 3px 0;
  border-radius: 3px;
  border: 1px solid var(--line);
  color: var(--ink2);
}

.u-type.c { border-color: #B9CBE0; color: #3A5A80; background: #EEF4FA; }
.u-type.h { border-color: #BCDCCB; color: var(--long); background: var(--long-soft); }
.u-type.k { border-color: #E4D2AF; color: var(--amber); background: var(--amber-soft); }

.u-title { font-size: 15px; line-height: 1.4; }

.u-title .u-desc {
  display: block;
  font-size: 13px;
  color: var(--ink2);
  margin-top: 2px;
}

.u-title .free-link {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--long);
  text-decoration: none;
  border: 1px solid #BCDCCB;
  background: var(--long-soft);
  border-radius: 3px;
  padding: 2px 6px;
  margin-left: 8px;
  white-space: nowrap;
}
.u-title .free-link:hover { border-color: var(--long); }

.u-title .locked {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--short);
  margin-left: 8px;
  white-space: nowrap;
}

.u-dur {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--ink2);
  text-align: right;
  white-space: nowrap;
}

/* ------------------------------------------------ references */

.refs { margin-top: 40px; }

.ref-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 16px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 0;
  padding: 12px 18px;
  text-decoration: none;
}

.ref-item:first-of-type { border-top: 1px solid var(--line); border-radius: 6px 6px 0 0; }
.ref-item:last-of-type { border-radius: 0 0 6px 6px; }
.ref-item:hover { border-left: 4px solid var(--long); padding-left: 15px; }

.ref-title { font-size: 15px; font-weight: 600; }
.ref-note { grid-column: 1 / -1; font-size: 13.5px; color: var(--ink2); }

.ref-src {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--long);
  white-space: nowrap;
  align-self: start;
  margin-top: 3px;
}

.refs .none, .units .none {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--short);
  background: var(--short-soft);
  border: 1px solid #E7C2BE;
  border-radius: 6px;
  padding: 14px 18px;
  line-height: 1.7;
}

/* ------------------------------------------------ self-check quiz */

.quiz { margin-top: 40px; }

.quiz-note {
  font-size: 13px;
  color: var(--ink2);
  margin: -8px 0 16px;
  max-width: 70ch;
}

.quiz-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 20px 24px;
  margin-bottom: 14px;
}

.quiz-q {
  font-weight: 600;
  font-size: 16px;
  margin-bottom: 14px;
}

.quiz-q .qno {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--long);
  margin-right: 8px;
  font-weight: 400;
}

.quiz-opts { display: grid; gap: 8px; }

.quiz-opt {
  text-align: left;
  font-family: var(--body);
  font-size: 14.5px;
  line-height: 1.45;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--paper);
  cursor: pointer;
  color: var(--ink);
  transition: border-color .12s ease;
}

.quiz-opt:hover:not(:disabled) { border-color: var(--ink); }
.quiz-opt:disabled { cursor: default; opacity: 0.75; }
.quiz-opt.correct {
  border-color: var(--long);
  background: var(--long-soft);
  opacity: 1;
  font-weight: 600;
}
.quiz-opt.wrong { border-color: var(--short); background: var(--short-soft); opacity: 1; }

.quiz-exp {
  margin-top: 12px;
  font-size: 14px;
  color: var(--ink2);
  border-left: 3px solid var(--long);
  padding-left: 12px;
  display: none;
}
.quiz-exp.show { display: block; }

/* ------------------------------------------------ audio row */

.audio-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.audio-row:empty { display: none; }

.audio-row .audio-label {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--ink2);
}

.audio-row audio {
  height: 34px;
  max-width: 380px;
  flex: 1 1 240px;
}

.tts-btn {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
}

.tts-btn:hover { border-color: var(--long); color: var(--long); }

.tts-sel {
  font-family: var(--mono);
  font-size: 11px;
  padding: 5px 6px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--panel);
  color: var(--ink2);
  max-width: 160px;
}

.tts-status {
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--long);
  letter-spacing: 0.05em;
}

/* ------------------------------------------------ lesson pages */

.u-title .u-link {
  color: inherit;
  text-decoration: none;
  font-weight: 600;
}
.u-title .u-link:hover { color: var(--long); text-decoration: underline; }

.lesson-head h1 { font-size: clamp(32px, 4.6vw, 50px); max-width: 24ch; }

.u-type-chip { letter-spacing: 0.08em; }
.u-type-chip.c { border-color: #B9CBE0; color: #3A5A80; background: #EEF4FA; }
.u-type-chip.h { border-color: #BCDCCB; color: var(--long); background: var(--long-soft); }
.u-type-chip.k { border-color: #E4D2AF; color: var(--amber); background: var(--amber-soft); }

.lp-done-btn {
  cursor: pointer;
  font-family: var(--mono);
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink2);
}
.lp-done-btn:hover { border-color: var(--long); color: var(--long); }
.lp-done-btn.is-done {
  background: var(--long);
  border-color: var(--long);
  color: #fff;
}

.lesson-body {
  margin-top: 26px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 30px 34px 34px;
}

.lesson-lede {
  font-size: 17px;
  color: var(--ink2);
  font-style: italic;
  margin-bottom: 20px;
  max-width: 68ch;
}

.lesson-body .lp-p {
  font-size: 16.5px;
  max-width: 70ch;
  margin: 0 0 14px;
}

.lesson-body .lp-p code,
.lesson-body .lp-list code,
.lesson-body td code,
.lp-takeaways code,
.lp-callout code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: 3px;
  padding: 1px 5px;
}

.lesson-body .lp-h {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: 23px;
  letter-spacing: 0.015em;
  margin: 30px 0 12px;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
}

.lp-codewrap {
  position: relative;
  margin: 6px 0 18px;
  background: #0E1B2C;
  border-radius: 6px;
  overflow: hidden;
}

.lp-codewrap .lp-lang {
  position: absolute;
  top: 8px;
  right: 12px;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #7C8DA3;
}

.lp-codewrap pre {
  overflow-x: auto;
  padding: 18px 20px;
}

.lp-codewrap pre code {
  font-family: var(--mono);
  font-size: 12.8px;
  line-height: 1.6;
  color: #DCE5EF;
  white-space: pre;
}

.lp-list {
  margin: 0 0 16px;
  padding-left: 24px;
  max-width: 68ch;
}
.lp-list li { font-size: 15.5px; padding: 3px 0; }
.lp-list li::marker { color: var(--long); font-family: var(--mono); font-size: 12px; }

.lp-callout {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 13px 16px;
  margin: 6px 0 18px;
  background: var(--paper);
}
.lp-callout p { font-size: 14.5px; max-width: 66ch; }
.lp-callout-tag {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.12em;
  padding: 3px 8px;
  border-radius: 3px;
  white-space: nowrap;
  margin-top: 2px;
  color: #fff;
  background: var(--ink2);
}
.lp-callout.k-tip { background: var(--long-soft); border-color: #BCDCCB; }
.lp-callout.k-tip .lp-callout-tag { background: var(--long); }
.lp-callout.k-warn { background: var(--short-soft); border-color: #E7C2BE; }
.lp-callout.k-warn .lp-callout-tag { background: var(--short); }
.lp-callout.k-note { background: #EEF4FA; border-color: #B9CBE0; }
.lp-callout.k-note .lp-callout-tag { background: #3A5A80; }

.lp-tablewrap { overflow-x: auto; margin: 6px 0 18px; }
.lp-tablewrap table {
  border-collapse: collapse;
  width: 100%;
  font-size: 14px;
}
.lp-tablewrap th {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: left;
  color: var(--ink2);
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 8px 12px;
}
.lp-tablewrap td {
  border: 1px solid var(--line);
  padding: 8px 12px;
  vertical-align: top;
}

.lp-takeaways {
  margin-top: 28px;
  border: 1px solid #BCDCCB;
  border-left: 4px solid var(--long);
  background: var(--long-soft);
  border-radius: 6px;
  padding: 16px 20px;
}
.lp-takeaways h3 {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 8px;
  color: var(--long);
}
.lp-takeaways ul { padding-left: 20px; }
.lp-takeaways li { font-size: 14.5px; padding: 2px 0; }

@media (max-width: 900px) {
  .lesson-body { padding: 20px 16px 24px; }
}

/* ------------------------------------------------ pager */

.pager {
  margin-top: 56px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.pager a {
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 6px;
  padding: 14px 18px;
  text-decoration: none;
  transition: border-color .15s ease;
}

.pager a:hover { border-color: var(--ink); }
.pager a.next { text-align: right; }
.pager a span {
  display: block;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink2);
  margin-bottom: 5px;
}
.pager a b {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: 18px;
  line-height: 1.1;
}

/* ------------------------------------------------ search results */

.search-results { padding-top: 34px; }

.sr-item {
  display: block;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 13px 18px;
  margin-bottom: 10px;
  text-decoration: none;
}

.sr-item:hover { border-color: var(--ink); }

.sr-item .sr-sec {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--long);
}

.sr-item .sr-title { font-size: 15.5px; margin-top: 3px; }

.sr-item mark { background: #F2E4B8; color: inherit; padding: 0 1px; }

/* ------------------------------------------------ footer */

.site-foot {
  border-top: 1px solid var(--line);
  padding: 26px 44px 34px;
  font-size: 13px;
  color: var(--ink2);
}

.site-foot .inner { max-width: 920px; margin: 0 auto; }
.site-foot p + p { margin-top: 6px; }
.site-foot a { color: var(--ink); }

.reset-btn {
  margin-top: 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--ink2);
  padding: 7px 12px;
  border-radius: 4px;
  cursor: pointer;
}
.reset-btn:hover { border-color: var(--short); color: var(--short); }

/* ------------------------------------------------ headings shared */

.block-head {
  font-family: var(--display);
  font-weight: 700;
  text-transform: uppercase;
  font-size: 26px;
  margin: 0 0 4px;
}

.block-sub {
  font-size: 13.5px;
  color: var(--ink2);
  margin-bottom: 16px;
}

.home-sections { margin-top: 56px; }

/* ------------------------------------------------ responsive */

@media (max-width: 1080px) {
  .content { padding: 0 28px 72px; }
}

@media (max-width: 900px) {
  :root { --rail-w: 0px; }

  .rail {
    transform: translateX(-105%);
    transition: transform .25s ease;
    width: 300px;
    box-shadow: 12px 0 32px rgba(14,27,44,0.18);
  }
  .rail.open { transform: translateX(0); }
  .scrim.show { display: block; }

  .main { margin-left: 0; }
  .topbar { display: flex; }

  .hero { padding-top: 34px; }
  .skills { grid-template-columns: 1fr; }
  .syllabus-grid { grid-template-columns: 1fr; }
  .pager { grid-template-columns: 1fr; }
  .pager a.next { text-align: left; }
  .content { padding: 0 18px 64px; }
  .site-foot { padding: 22px 18px 30px; }
  .unit-row { grid-template-columns: 26px 58px 1fr auto; gap: 0 10px; padding: 10px 12px 10px 10px; }
  .primer { padding: 20px 18px 22px; }
}