.lesson-prose {
  --navy: #0d2448;
  --blue: #2557a7;
  --blue2: #1e4a8e;
  --sky: #3a7ec4;
  --bg: #d0d0d0;
  --bg2: #c4c4c4;
  --surface: #e0e0e0;
  --surf2: #d8d8d8;
  --surface2: #d8d8d8;
  --white: #f2f4f6;
  --paper: #eaeaea;
  --ink: #1a1a1a;
  --ink2: #3a3a3a;
  --ink3: #5a5a5a;
  --ink4: #7a7a7a;
  --border: #a8a8a8;
  --border2: #b8b8b8;
  --bdr: #a8a8a8;
  --bdr2: #b8b8b8;
  --border-dark: #909090;
  --accent: #3a6ea5;
  --accent2: #0d2448;
  --accent-pale: rgba(13, 36, 72, 0.08);
  --text: #1a1a1a;
  --text-muted: #4a4a4a;
  --text-dim: #6a6a6a;
  --red: #c0392b;
  --red-pale: rgba(192, 57, 43, 0.1);
  --green: #1a8a50;
  --green-pale: rgba(26, 138, 80, 0.1);
  --gold: #b8860b;
  --gold-pale: rgba(184, 134, 11, 0.1);
  --teal: #1a8a7a;
  --teal-pale: rgba(26, 138, 122, 0.1);
  --purple: #6a4ab8;
  --purple-pale: rgba(106, 74, 184, 0.1);
  --amber: #8a6a00;
  --amber2: #a06010;
  --amber-pale: rgba(138, 106, 0, 0.1);
  --cyan: #1a7a9a;
  --cyan2: #0d5a70;
  --orange: #d06020;
  --rose: #b0305a;
  --steel: #4a7fa5;
  --concrete: #8a8070;
  --wood: #b5813a;
  --alum: #7a9ab5;
  --rubber: #3a7a5a;
  --oil: #a07a08;
  --oil2: #c89818;
  --oil-pale: rgba(160, 122, 8, 0.08);
  --volt: #c88a00;
  --amp: #1a7aa0;
  --blue-pale: rgba(37, 87, 167, 0.08);
  --sidebar-w: 0px;
  --sw: 0px;
}
.lesson-prose * {
  font-family: var(--font-sans) !important;
}
.lesson-prose h1,
.lesson-prose h2,
.lesson-prose h3,
.lesson-prose h4 {
  font-family: var(--font-display) !important;
}
.lesson-prose .c-lbl {
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--sky);
  margin-bottom: 13px;
  position: relative;
}
.lesson-prose .c-title {
  font-family: "Barlow", sans-serif;
  font-size: 52px;
  font-weight: 700;
  color: #fff;
  line-height: 1;
  max-width: 660px;
  margin-bottom: 10px;
  position: relative;
}
.lesson-prose .c-title em {
  color: var(--sky);
  font-style: normal;
}
.lesson-prose .c-sub {
  font-family: "Barlow", serif;
  font-style: italic;
  font-size: 18px;
  color: rgba(255, 255, 255, 0.48);
  max-width: 520px;
  margin-bottom: 26px;
  position: relative;
}
.lesson-prose .c-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  position: relative;
}
.lesson-prose .pill {
  background: rgba(2, 132, 199, 0.12);
  border: 1px solid rgba(2, 132, 199, 0.28);
  padding: 4px 11px;
  border-radius: 2px;
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 1px;
  color: rgba(2, 132, 199, 0.85);
}
.lesson-prose .body {
  max-width: 960px;
  margin: 0 auto;
  padding: 62px 68px;
}
.lesson-prose .sec {
  margin-bottom: 82px;
}
.lesson-prose .ey {
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--sky);
  margin-bottom: 7px;
}
.lesson-prose .sec h2 {
  font-family: "Barlow", sans-serif;
  font-size: 31px;
  font-weight: 700;
  color: var(--navy);
  line-height: 1.1;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--bdr2);
}
.lesson-prose .sec h3 {
  font-family: "Barlow", sans-serif;
  font-size: 16px;
  font-weight: 600;
  color: var(--sky);
  margin: 26px 0 9px;
  letter-spacing: 0.2px;
}
.lesson-prose .co {
  display: flex;
  gap: 13px;
  padding: 15px 19px;
  margin: 18px 0;
  border-radius: 3px;
  border-left: 3px solid;
}
.lesson-prose .co-i {
  font-size: 16px;
  flex-shrink: 0;
  margin-top: 2px;
}
.lesson-prose .co-b {
  flex: 1;
}
.lesson-prose .co-t {
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 3px;
  text-transform: uppercase;
  font-weight: 500;
  margin-bottom: 4px;
}
.lesson-prose .co p {
  font-size: 14px;
  margin: 0;
  line-height: 1.7;
}
.lesson-prose .co.sky {
  background: rgba(2, 132, 199, 0.07);
  border-color: var(--sky);
}
.lesson-prose .co.sky .co-t {
  color: var(--sky);
}
.lesson-prose .co.grn {
  background: rgba(21, 128, 61, 0.06);
  border-color: var(--green);
}
.lesson-prose .co.grn .co-t {
  color: var(--green);
}
.lesson-prose .co.red {
  background: rgba(220, 38, 38, 0.06);
  border-color: var(--red);
}
.lesson-prose .co.red .co-t {
  color: var(--red);
}
.lesson-prose .co.amb {
  background: var(--gold-pale);
  border-color: var(--amber);
}
.lesson-prose .co.amb .co-t {
  color: var(--amber);
}
.lesson-prose .co.pur {
  background: rgba(109, 40, 217, 0.06);
  border-color: var(--purple);
}
.lesson-prose .co.pur .co-t {
  color: var(--purple);
}
.lesson-prose .dialogue {
  background: var(--paper);
  border: 1px solid var(--bdr);
  border-radius: 4px;
  overflow: hidden;
  margin: 22px 0;
}
.lesson-prose .dialogue-title {
  background: var(--navy);
  padding: 9px 18px;
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.45);
}
.lesson-prose .dialogue-body {
  padding: 20px;
}
.lesson-prose .msg {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}
.lesson-prose .msg:last-child {
  margin-bottom: 0;
}
.lesson-prose .msg-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  margin-top: 2px;
}
.lesson-prose .msg-content {
  flex: 1;
}
.lesson-prose .msg-name {
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--ink4);
  margin-bottom: 4px;
}
.lesson-prose .msg-bubble {
  padding: 11px 14px;
  border-radius: 0 8px 8px 8px;
  font-size: 14px;
  line-height: 1.65;
}
.lesson-prose .msg.engineer .msg-avatar {
  background: rgba(30, 64, 175, 0.15);
}
.lesson-prose .msg.engineer .msg-name {
  color: var(--blue);
}
.lesson-prose .msg.engineer .msg-bubble {
  background: rgba(30, 64, 175, 0.07);
  border: 1px solid rgba(30, 64, 175, 0.15);
  color: var(--ink2);
}
.lesson-prose .msg.client .msg-avatar {
  background: rgba(109, 40, 217, 0.12);
}
.lesson-prose .msg.client .msg-name {
  color: var(--purple);
}
.lesson-prose .msg.client .msg-bubble {
  background: rgba(109, 40, 217, 0.06);
  border: 1px solid rgba(109, 40, 217, 0.15);
  color: var(--ink2);
}
.lesson-prose .msg.sales .msg-avatar {
  background: rgba(2, 132, 199, 0.15);
}
.lesson-prose .msg.sales .msg-name {
  color: var(--sky);
}
.lesson-prose .msg.sales .msg-bubble {
  background: rgba(2, 132, 199, 0.07);
  border: 1px solid rgba(2, 132, 199, 0.18);
  color: var(--ink2);
}
.lesson-prose .msg.bad .msg-avatar {
  background: rgba(220, 38, 38, 0.12);
}
.lesson-prose .msg.bad .msg-name {
  color: var(--red);
}
.lesson-prose .msg.bad .msg-bubble {
  background: rgba(220, 38, 38, 0.06);
  border: 1px solid rgba(220, 38, 38, 0.18);
  color: var(--ink2);
}
.lesson-prose .msg-note {
  font-family: "Barlow", monospace;
  font-size: 10px;
  color: var(--ink4);
  margin-top: 5px;
  padding-left: 4px;
}
.lesson-prose .msg-note.good {
  color: var(--green);
}
.lesson-prose .msg-note.bad {
  color: var(--red);
}
.lesson-prose .ba-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin: 20px 0;
}
.lesson-prose .ba-card {
  border-radius: 4px;
  overflow: hidden;
}
.lesson-prose .ba-head {
  padding: 10px 16px;
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  font-weight: 500;
}
.lesson-prose .ba-head.before {
  background: rgba(220, 38, 38, 0.1);
  color: var(--red);
}
.lesson-prose .ba-head.after {
  background: rgba(21, 128, 61, 0.1);
  color: var(--green);
}
.lesson-prose .ba-body {
  padding: 14px 16px;
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink2);
  font-family: "Barlow", serif;
}
.lesson-prose .ba-card.before-card {
  background: var(--paper);
  border: 1px solid rgba(220, 38, 38, 0.25);
}
.lesson-prose .ba-card.after-card {
  background: var(--paper);
  border: 1px solid rgba(21, 128, 61, 0.25);
}
.lesson-prose .ba-note {
  font-family: "Barlow", monospace;
  font-size: 10px;
  margin-top: 8px;
}
.lesson-prose .ba-note.bad {
  color: var(--red);
}
.lesson-prose .ba-note.good {
  color: var(--green);
}
.lesson-prose .term-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 22px 0;
}
.lesson-prose .term-card {
  background: var(--paper);
  border: 1px solid var(--bdr);
  border-radius: 4px;
  padding: 16px;
  position: relative;
  overflow: hidden;
}
.lesson-prose .term-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
}
.lesson-prose .term-symbol {
  font-family: "Barlow", monospace;
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 6px;
  display: block;
}
.lesson-prose .term-name {
  font-family: "Barlow", sans-serif;
  font-size: 14px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 4px;
}
.lesson-prose .term-unit {
  font-family: "Barlow", monospace;
  font-size: 10px;
  color: var(--ink4);
  margin-bottom: 8px;
}
.lesson-prose .term-card p {
  font-size: 13px;
  color: var(--ink3);
  margin: 0 0 8px;
  line-height: 1.6;
  font-family: "Barlow", serif;
}
.lesson-prose .term-usage {
  font-family: "Barlow", monospace;
  font-size: 10px;
  line-height: 1.7;
}
.lesson-prose .template {
  background: var(--paper);
  border: 1px solid var(--bdr);
  border-radius: 4px;
  margin: 14px 0;
  overflow: hidden;
}
.lesson-prose .template-head {
  padding: 9px 16px;
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  background: var(--accent-pale);
  color: var(--accent);
}
.lesson-prose .template-body {
  padding: 14px 16px;
}
.lesson-prose .template-phrase {
  font-family: "Barlow", monospace;
  font-size: 13px;
  color: var(--navy);
  line-height: 1.8;
  padding: 6px 10px;
  background: rgba(30, 64, 175, 0.04);
  border-left: 2px solid var(--sky);
  border-radius: 0 3px 3px 0;
  margin: 6px 0;
}
.lesson-prose .template-note {
  font-family: "Barlow", serif;
  font-size: 13px;
  color: var(--ink3);
  margin-top: 8px;
}
.lesson-prose .rfq {
  background: var(--navy);
  border-radius: 4px;
  padding: 24px;
  margin: 22px 0;
  font-family: "Barlow", monospace;
}
.lesson-prose .rfq-title {
  font-size: 10px;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: rgba(2, 132, 199, 0.8);
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.lesson-prose .rfq-line {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 12px;
}
.lesson-prose .rfq-label {
  color: rgba(255, 255, 255, 0.4);
}
.lesson-prose .rfq-value {
  color: #fff;
  font-weight: 500;
}
.lesson-prose .rfq-value.flag {
  color: rgba(220, 38, 38, 0.9);
}
.lesson-prose .rfq-value.ok {
  color: rgba(21, 128, 61, 0.9);
}
.lesson-prose .rfq-value.warn {
  color: rgba(217, 119, 6, 0.9);
}
.lesson-prose .obj-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 22px 0;
}
.lesson-prose .obj-card {
  background: var(--paper);
  border: 1px solid var(--bdr);
  border-radius: 4px;
  overflow: hidden;
}
.lesson-prose .obj-question {
  padding: 12px 18px;
  background: rgba(109, 40, 217, 0.07);
  border-bottom: 1px solid rgba(109, 40, 217, 0.15);
  font-size: 15px;
  color: var(--purple);
  font-family: "Barlow", serif;
  font-style: italic;
}
.lesson-prose .obj-body {
  padding: 16px 18px;
}
.lesson-prose .obj-body p {
  font-size: 14px;
  margin: 0 0 10px;
  color: var(--ink2);
}
.lesson-prose .obj-body p:last-child {
  margin: 0;
}
.lesson-prose .obj-phrase {
  font-family: "Barlow", monospace;
  font-size: 12px;
  color: var(--sky);
  padding: 8px 12px;
  background: rgba(2, 132, 199, 0.07);
  border-left: 2px solid var(--sky);
  border-radius: 0 3px 3px 0;
  margin: 8px 0;
}
.lesson-prose .spec-vis {
  background: var(--paper);
  border: 1px solid var(--bdr);
  border-radius: 4px;
  margin: 20px 0;
  overflow: hidden;
}
.lesson-prose .spec-vis-head {
  background: var(--navy);
  padding: 10px 18px;
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.4);
}
.lesson-prose .mistake-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 13px;
  margin: 22px 0;
}
.lesson-prose .mistake-card {
  background: var(--paper);
  border: 1px solid var(--bdr);
  border-top: 3px solid var(--red);
  border-radius: 0 0 4px 4px;
  padding: 16px;
}
.lesson-prose .mistake-card h4 {
  font-family: "Barlow", sans-serif;
  font-size: 14px;
  font-weight: 700;
  color: var(--red);
  margin-bottom: 6px;
}
.lesson-prose .mistake-card p {
  font-size: 13.5px;
  color: var(--ink3);
  margin: 0 0 8px;
  line-height: 1.6;
  font-family: "Barlow", serif;
}
.lesson-prose .mistake-ex {
  font-family: "Barlow", monospace;
  font-size: 10px;
  line-height: 1.7;
}
.lesson-prose .sumbox {
  background: var(--navy);
  border-top: 4px solid var(--sky);
  padding: 40px 50px;
  margin-top: 56px;
}
.lesson-prose .sumbox h2 {
  font-family: "Barlow", sans-serif;
  font-size: 26px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 20px;
  padding-bottom: 13px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.lesson-prose .tl {
  list-style: none;
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}
.lesson-prose .tl li {
  padding: 7px 0 7px 20px;
  position: relative;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 14px;
  color: rgba(255, 255, 255, 0.55);
  line-height: 1.6;
}
.lesson-prose .tl li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--sky);
  font-size: 10px;
  top: 10px;
}
.lesson-prose .tl li strong {
  color: #fff;
}
.lesson-prose .fl {
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.22);
}
.lesson-prose .fr {
  font-family: "Barlow", monospace;
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: rgba(2, 132, 199, 0.6);
}
.lesson-prose .circuit-decoration {
  position: relative;
  overflow: hidden;
}
.lesson-prose .circuit-decoration::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 200px;
  height: 100%;
  background:
    radial-gradient(circle at 80% 20%, rgba(2, 132, 199, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 90% 70%, rgba(30, 64, 175, 0.05) 0%, transparent 40%);
  pointer-events: none;
}
@keyframes bar1 {
  0%,
  100% {
    height: 20px;
  }
  50% {
    height: 40px;
  }
}
@keyframes bar2 {
  0%,
  100% {
    height: 35px;
  }
  50% {
    height: 15px;
  }
}
@keyframes bar3 {
  0%,
  100% {
    height: 25px;
  }
  50% {
    height: 45px;
  }
}
@keyframes bar4 {
  0%,
  100% {
    height: 40px;
  }
  50% {
    height: 20px;
  }
}
@keyframes bar5 {
  0%,
  100% {
    height: 15px;
  }
  50% {
    height: 38px;
  }
}
.lesson-prose .freq-bars {
  display: flex;
  align-items: flex-end;
  gap: 4px;
  height: 50px;
}
.lesson-prose .freq-bar {
  width: 8px;
  background: var(--sky);
  border-radius: 2px 2px 0 0;
  opacity: 0.7;
}
.lesson-prose .freq-bar:nth-child(1) {
  animation: bar1 1.2s ease-in-out infinite;
}
.lesson-prose .freq-bar:nth-child(2) {
  animation: bar2 1.4s ease-in-out infinite;
}
.lesson-prose .freq-bar:nth-child(3) {
  animation: bar3 1.1s ease-in-out infinite;
}
.lesson-prose .freq-bar:nth-child(4) {
  animation: bar4 1.3s ease-in-out infinite;
}
.lesson-prose .freq-bar:nth-child(5) {
  animation: bar5 1.5s ease-in-out infinite;
}
@keyframes blink {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0;
  }
}
.lesson-prose .cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--sky);
  vertical-align: middle;
  animation: blink 1s infinite;
}
@keyframes signal {
  0% {
    transform: scale(1);
    opacity: 0.8;
  }
  100% {
    transform: scale(2.5);
    opacity: 0;
  }
}
.lesson-prose .signal {
  position: relative;
  display: inline-block;
}
.lesson-prose .signal::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: var(--green);
  animation: signal 2s infinite;
}
@keyframes highlight-fade {
  0% {
    background: rgba(2, 132, 199, 0.25);
  }
  100% {
    background: rgba(2, 132, 199, 0.07);
  }
}
.lesson-prose .kterm {
  background: rgba(2, 132, 199, 0.1);
  color: var(--navy);
  font-family: "Barlow", monospace;
  font-size: 0.88em;
  padding: 1px 5px;
  border-radius: 3px;
  font-weight: 500;
  border: 1px solid rgba(2, 132, 199, 0.2);
}
@media (max-width: 900px) {
  .lesson-prose .body {
    padding: 28px 20px;
  }
  .lesson-prose .term-grid,
  .lesson-prose .ba-grid,
  .lesson-prose .mistake-grid {
    grid-template-columns: 1fr;
  }
}
.lesson-prose .content,
.lesson-prose .main-content {
  margin-left: 0 !important;
}
.lesson-prose .hero {
  background: #0d2448 !important;
  color: #f2f4f6 !important;
}
.lesson-prose .hero h1 {
  color: #ffffff !important;
}
.lesson-prose .hero-label {
  color: #a8c4e8 !important;
}
.lesson-prose .hero-sub {
  color: #8aa8cc !important;
}
@media (max-width: 640px) {
  .lesson-prose [class*="grid"],
  .lesson-prose .flow,
  .lesson-prose .integ-flow,
  .lesson-prose .two-col,
  .lesson-prose .tl,
  .lesson-prose .law-cards,
  .lesson-prose .card-grid {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 0.7rem !important;
  }
  .lesson-prose [style*="grid-template-columns"] {
    grid-template-columns: 1fr !important;
  }
  .lesson-prose .strip,
  .lesson-prose .flow,
  .lesson-prose .integ-flow {
    flex-wrap: wrap !important;
  }
}