:root {
  --bg: #07090d;
  --bg-soft: #0b0e14;
  --surface: #0e121a;
  --surface-2: #121722;
  --surface-3: #171d29;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.16);
  --text: #f4f7fb;
  --muted: #97a1b3;
  --muted-2: #697386;
  --accent: #78f5c7;
  --accent-2: #8da2ff;
  --accent-3: #d68cff;
  --danger: #ff8a9a;
  --warning: #ffd479;
  --shadow: 0 30px 80px rgba(0, 0, 0, 0.35);
  --header-bg: rgba(7, 9, 13, 0.78);
  --code-bg: #090c12;
  --selection: #263f38;
  --radius: 18px;
  --radius-lg: 28px;
  --max: 1240px;
  --font:
    Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}
html[data-theme="light"] {
  --bg: #f5f7fb;
  --bg-soft: #edf1f7;
  --surface: #fff;
  --surface-2: #f8faff;
  --surface-3: #eef2f8;
  --line: rgba(16, 24, 40, 0.1);
  --line-strong: rgba(16, 24, 40, 0.18);
  --text: #101521;
  --muted: #536074;
  --muted-2: #7a8597;
  --accent: #008b69;
  --accent-2: #5267da;
  --accent-3: #8c52c7;
  --shadow: 0 28px 70px rgba(31, 45, 75, 0.12);
  --header-bg: rgba(245, 247, 251, 0.82);
  --code-bg: #f1f4f8;
  --selection: #b9efdf;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
}
::selection {
  background: var(--selection);
}
a {
  color: inherit;
  text-decoration: none;
}
button,
input {
  font: inherit;
}
button {
  color: inherit;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: fixed;
  left: 20px;
  top: -80px;
  z-index: 999;
  background: var(--accent);
  color: #04110d;
  padding: 10px 16px;
  border-radius: 10px;
  font-weight: 800;
}
.skip-link:focus {
  top: 16px;
}
.site-grid {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -2;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.55), transparent 78%);
  opacity: 0.26;
}
.site-grid:after {
  content: "";
  position: absolute;
  width: 760px;
  height: 760px;
  left: 50%;
  top: -440px;
  transform: translateX(-50%);
  background: radial-gradient(
    circle,
    rgba(104, 246, 198, 0.14),
    rgba(141, 162, 255, 0.08) 42%,
    transparent 68%
  );
  filter: blur(10px);
}
.section-shell {
  width: min(calc(100% - 40px), var(--max));
  margin-inline: auto;
}
.section-block {
  padding-block: 112px;
}
.eyebrow {
  margin: 0 0 14px;
  color: var(--accent);
  font: 700 12px/1.2 var(--mono);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 0.65s ease,
    transform 0.65s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid transparent;
  background: var(--header-bg);
  backdrop-filter: blur(18px);
  transition:
    border-color 0.25s,
    box-shadow 0.25s;
}
.site-header.is-scrolled {
  border-bottom-color: var(--line);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}
.header-inner {
  width: min(calc(100% - 40px), var(--max));
  height: 76px;
  margin: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}
.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  background: linear-gradient(145deg, var(--surface-2), var(--surface));
  box-shadow: inset 0 1px rgba(255, 255, 255, 0.06);
  font: 800 15px/1 var(--mono);
  color: var(--accent);
}
.brand-mark.mini {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  display: inline-grid;
}
.brand-copy {
  display: flex;
  flex-direction: column;
}
.brand-copy strong {
  font-size: 14px;
  letter-spacing: 0.01em;
}
.brand-copy small {
  font: 500 10px/1.3 var(--mono);
  color: var(--muted);
  letter-spacing: 0.03em;
}
.desktop-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}
.desktop-nav a,
.mobile-nav a {
  padding: 9px 13px;
  border-radius: 9px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
  transition: 0.2s;
}
.desktop-nav a:hover,
.desktop-nav a.is-active {
  color: var(--text);
  background: var(--surface-2);
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.icon-button {
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 10px;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: 0.2s;
}
.icon-button:hover {
  border-color: var(--line-strong);
  transform: translateY(-1px);
}
.icon-button svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.icon-button a svg,
.icon-button svg path:first-child:last-child {
  fill: currentColor;
  stroke: none;
}
.mobile-menu-button {
  display: none;
}
.mobile-nav {
  display: none;
  padding: 8px 20px 18px;
  border-top: 1px solid var(--line);
}
.hero {
  min-height: calc(100vh - 76px);
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(430px, 0.92fr);
  align-items: center;
  gap: 72px;
  padding-block: 80px 90px;
}
.availability-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 28px;
  padding: 7px 11px;
  border: 1px solid rgba(120, 245, 199, 0.25);
  background: rgba(120, 245, 199, 0.07);
  border-radius: 999px;
  color: var(--accent);
  font: 700 11px/1 var(--mono);
  letter-spacing: 0.03em;
}
.availability-pill span,
.network-dot,
.available-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 16px var(--accent);
}
.hero h1 {
  font-size: clamp(50px, 6vw, 84px);
  line-height: 0.98;
  letter-spacing: -0.055em;
  margin: 0;
  max-width: 800px;
}
.hero h1 span {
  color: var(--muted);
  font-weight: 560;
}
.hero-lead {
  max-width: 690px;
  color: var(--muted);
  font-size: 19px;
  line-height: 1.7;
  margin: 28px 0 0;
}
.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 34px;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 18px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  font-weight: 750;
  font-size: 13px;
  transition: 0.2s;
  cursor: pointer;
  background: transparent;
}
.button svg,
.card-action svg,
.active-course > svg,
.lesson-row b svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform 0.2s;
}
.button.primary {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}
.button.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 35px rgba(120, 245, 199, 0.13);
}
.button.primary:hover svg,
.card-action:hover svg,
.active-course:hover > svg {
  transform: translateX(4px);
}
.button.secondary {
  background: var(--surface);
  color: var(--text);
}
.button.secondary:hover {
  background: var(--surface-2);
  transform: translateY(-2px);
}
.button.compact {
  min-height: 42px;
}
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: 52px;
  border-top: 1px solid var(--line);
}
.hero-stats div {
  padding: 22px 18px 0 0;
}
.hero-stats strong {
  display: block;
  font: 700 22px/1 var(--mono);
}
.hero-stats span {
  display: block;
  color: var(--muted);
  font-size: 11px;
  margin-top: 8px;
}
.hero-console {
  border: 1px solid var(--line-strong);
  border-radius: 20px;
  background: linear-gradient(
    180deg,
    rgba(18, 23, 34, 0.96),
    rgba(8, 11, 17, 0.98)
  );
  box-shadow:
    var(--shadow),
    inset 0 1px rgba(255, 255, 255, 0.07);
  overflow: hidden;
  transform: perspective(1200px) rotateY(-2deg) rotateX(1deg);
}
html[data-theme="light"] .hero-console {
  background: linear-gradient(180deg, #fff, #edf2f8);
}
.console-bar {
  height: 46px;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 15px;
  color: var(--muted);
  font: 600 10px/1 var(--mono);
}
.console-bar > div {
  display: flex;
  gap: 6px;
}
.console-bar > div span {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #ff6c71;
}
.console-bar > div span:nth-child(2) {
  background: #ffd66c;
}
.console-bar > div span:nth-child(3) {
  background: #5be39b;
}
.console-bar > span {
  text-align: right;
}
.console-body {
  padding: 27px 25px 30px;
  font: 500 12px/1.65 var(--mono);
}
.console-body p {
  margin: 0;
}
.prompt {
  color: var(--accent);
}
.console-response {
  color: var(--muted);
  padding: 4px 0 18px;
}
.console-step {
  display: grid;
  grid-template-columns: 36px 1fr auto;
  align-items: center;
  gap: 12px;
  border: 1px solid var(--line);
  border-radius: 11px;
  padding: 12px;
  margin: 8px 0;
  background: rgba(255, 255, 255, 0.018);
}
.console-step > span {
  color: var(--muted-2);
}
.console-step strong {
  display: block;
  color: var(--text);
  font-weight: 650;
}
.console-step small {
  display: block;
  color: var(--muted);
  margin-top: 2px;
}
.console-step b {
  font-size: 9px;
  color: var(--muted-2);
}
.console-step.active {
  border-color: rgba(120, 245, 199, 0.18);
  background: rgba(120, 245, 199, 0.035);
}
.console-step.active b {
  color: var(--accent);
}
.console-command {
  padding-top: 20px;
  color: var(--text);
}
.console-command i {
  display: inline-block;
  width: 7px;
  height: 14px;
  background: var(--accent);
  vertical-align: -2px;
  margin-left: 3px;
  animation: blink 1s steps(2, end) infinite;
}
.console-footer {
  height: 38px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 16px;
  color: var(--muted);
  font: 500 9px/1 var(--mono);
}
.console-footer span:first-child {
  display: flex;
  align-items: center;
  gap: 7px;
}
.console-footer i {
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
}
@keyframes blink {
  50% {
    opacity: 0;
  }
}
.trust-strip {
  border-block: 1px solid var(--line);
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--muted-2);
  font: 700 10px/1 var(--mono);
  letter-spacing: 0.12em;
}
.trust-strip i {
  width: 3px;
  height: 3px;
  background: var(--line-strong);
  border-radius: 50%;
}
.section-heading {
  max-width: 800px;
  margin-bottom: 48px;
}
.section-heading.split {
  max-width: none;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 80px;
  align-items: end;
}
.section-heading h2,
.overview-copy h2 {
  font-size: clamp(34px, 4.5vw, 58px);
  line-height: 1.05;
  letter-spacing: -0.045em;
  margin: 0;
}
.section-heading > p:last-child,
.section-heading.split > p,
.overview-copy > p:last-child {
  color: var(--muted);
  font-size: 17px;
  margin: 18px 0 0;
}
.roadmap-list {
  position: relative;
}
.roadmap-list:before {
  content: "";
  position: absolute;
  left: 31px;
  top: 38px;
  bottom: 38px;
  width: 1px;
  background: linear-gradient(var(--accent), var(--accent-2), var(--line));
}
.roadmap-stage {
  position: relative;
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 28px;
  padding: 0 0 40px;
}
.stage-index {
  position: relative;
  z-index: 1;
  width: 64px;
  height: 64px;
  border-radius: 18px;
  border: 1px solid var(--line-strong);
  background: var(--bg);
  display: grid;
  place-items: center;
  font: 700 13px/1 var(--mono);
  color: var(--accent);
}
.stage-body {
  border: 1px solid var(--line);
  background: linear-gradient(
    130deg,
    var(--surface),
    rgba(255, 255, 255, 0.012)
  );
  border-radius: var(--radius);
  padding: 27px 30px;
}
.stage-body h3 {
  font-size: 24px;
  margin: 0;
  letter-spacing: -0.02em;
}
.stage-body > p:not(.eyebrow) {
  color: var(--muted);
  margin: 8px 0 18px;
}
.roadmap-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.roadmap-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg-soft);
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
}
.roadmap-chip span {
  font: 700 9px/1 var(--mono);
  color: var(--muted-2);
}
.roadmap-chip.available {
  border-color: rgba(120, 245, 199, 0.28);
  color: var(--text);
  background: rgba(120, 245, 199, 0.05);
}
.roadmap-chip.available span {
  color: var(--accent);
}
.catalog-toolbar,
.course-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 16px;
}
.search-box {
  min-height: 48px;
  flex: 1;
  max-width: 560px;
  display: flex;
  align-items: center;
  gap: 10px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  padding: 0 15px;
}
.search-box:focus-within {
  border-color: var(--accent-2);
  box-shadow: 0 0 0 3px rgba(141, 162, 255, 0.08);
}
.search-box svg,
.sidebar-search svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: var(--muted);
  stroke-width: 1.8;
}
.search-box input,
.sidebar-search input {
  width: 100%;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
}
.search-box input::placeholder,
.sidebar-search input::placeholder {
  color: var(--muted-2);
}
.filter-toggle {
  display: none;
}
.filter-row {
  display: flex;
  gap: 7px;
  overflow: auto;
  padding-bottom: 10px;
  scrollbar-width: none;
}
.filter-row button {
  white-space: nowrap;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  border-radius: 999px;
  padding: 8px 12px;
  font-size: 10px;
  font-weight: 750;
  cursor: pointer;
}
.filter-row button:hover,
.filter-row button.is-active {
  color: var(--text);
  border-color: var(--line-strong);
  background: var(--surface-2);
}
.catalog-summary {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font: 600 11px/1 var(--mono);
  margin: 20px 0;
}
.catalog-summary span:last-child {
  display: flex;
  align-items: center;
  gap: 7px;
}
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}
.course-card {
  min-height: 330px;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(
    145deg,
    var(--surface),
    rgba(255, 255, 255, 0.008)
  );
  padding: 22px;
  transition:
    border-color 0.25s,
    transform 0.25s,
    background 0.25s;
}
.course-card:hover {
  transform: translateY(-4px);
  border-color: var(--line-strong);
  background: var(--surface-2);
}
.course-card[hidden] {
  display: none;
}
.course-card-top {
  display: flex;
  justify-content: space-between;
  align-items: start;
}
.course-glyph {
  min-width: 44px;
  height: 36px;
  padding: 0 9px;
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 9px;
  background: var(--bg-soft);
  font: 800 10px/1 var(--mono);
  letter-spacing: 0.02em;
  color: var(--accent-2);
}
.course-glyph.giant {
  height: 84px;
  min-width: 100px;
  border-radius: 20px;
  font-size: 21px;
}
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted-2);
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.status-badge.available {
  color: var(--accent);
  border-color: rgba(120, 245, 199, 0.22);
  background: rgba(120, 245, 199, 0.05);
}
.status-badge.available span {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
}
.course-category {
  color: var(--muted-2);
  font: 700 10px/1.2 var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 28px 0 9px;
}
.course-card h3 {
  font-size: 23px;
  line-height: 1.15;
  letter-spacing: -0.025em;
  margin: 0;
}
.course-card > p:not(.course-category) {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.65;
  margin: 13px 0 22px;
}
.card-action {
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 750;
  color: var(--text);
}
.card-action.muted {
  color: var(--muted-2);
}
.empty-state {
  text-align: center;
  padding: 80px 20px;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
}
.empty-state > span {
  display: inline-grid;
  place-items: center;
  width: 54px;
  height: 54px;
  border-radius: 14px;
  background: var(--surface-2);
  font: 800 15px/1 var(--mono);
  color: var(--accent);
}
.empty-state h3 {
  margin: 18px 0 4px;
}
.empty-state p {
  margin: 0;
  color: var(--muted);
}
.method-section {
  background: linear-gradient(
    180deg,
    transparent,
    var(--bg-soft) 18%,
    var(--bg-soft) 82%,
    transparent
  );
  border-block: 1px solid var(--line);
}
.method-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
.method-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 25px;
  min-height: 245px;
}
.method-card > span {
  font: 700 11px/1 var(--mono);
  color: var(--accent);
}
.method-card h3 {
  font-size: 20px;
  margin: 65px 0 8px;
}
.method-card p {
  color: var(--muted);
  font-size: 13px;
  margin: 0;
}
.active-course-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.active-course {
  min-height: 230px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  padding: 30px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 25px;
  overflow: hidden;
  position: relative;
  transition: 0.25s;
}
.active-course:before {
  content: "";
  position: absolute;
  width: 240px;
  height: 240px;
  border-radius: 50%;
  right: -80px;
  top: -100px;
  background: radial-gradient(
    circle,
    rgba(120, 245, 199, 0.16),
    transparent 68%
  );
}
.active-course.git:before {
  background: radial-gradient(
    circle,
    rgba(141, 162, 255, 0.18),
    transparent 68%
  );
}
.active-course:hover {
  transform: translateY(-5px);
  background: var(--surface);
}
.large-glyph {
  width: 82px;
  height: 82px;
  display: grid;
  place-items: center;
  border-radius: 19px;
  border: 1px solid var(--line-strong);
  font: 800 17px/1 var(--mono);
  color: var(--accent);
}
.active-course.git .large-glyph {
  color: var(--accent-2);
}
.active-course p {
  margin: 0;
  color: var(--muted);
  font: 700 10px/1 var(--mono);
  text-transform: uppercase;
}
.active-course h3 {
  font-size: 28px;
  margin: 7px 0 4px;
}
.active-course div > span {
  color: var(--muted);
  font-size: 12px;
}
.active-course > svg {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: var(--text);
  stroke-width: 1.8;
  z-index: 1;
}
.support-panel {
  position: relative;
  overflow: hidden;
  margin: 40px 0 90px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  padding: 46px;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 70px;
  background: linear-gradient(135deg, var(--surface), var(--bg-soft));
}
.support-orbit {
  position: absolute;
  width: 480px;
  height: 480px;
  border: 1px solid rgba(141, 162, 255, 0.12);
  border-radius: 50%;
  right: -260px;
  top: -250px;
  box-shadow:
    0 0 0 60px rgba(141, 162, 255, 0.025),
    0 0 0 120px rgba(120, 245, 199, 0.018);
}
.support-copy,
.wallet-card {
  position: relative;
  z-index: 1;
}
.support-copy h2 {
  font-size: 36px;
  line-height: 1.1;
  letter-spacing: -0.035em;
  margin: 0;
}
.support-copy > p:not(.eyebrow) {
  color: var(--muted);
  margin: 15px 0 22px;
}
.social-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.social-row a {
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 7px 10px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
}
.social-row a:hover {
  color: var(--text);
  border-color: var(--line-strong);
}
.wallet-card {
  align-self: center;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--bg);
  padding: 21px;
}
.wallet-head {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font: 700 10px/1 var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.07em;
}
.wallet-card code {
  display: block;
  margin: 18px 0;
  padding: 13px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: var(--surface);
  font: 600 11px/1.4 var(--mono);
  overflow-wrap: anywhere;
}
.copy-wallet {
  width: 100%;
  min-height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 0;
  border-radius: 9px;
  background: var(--text);
  color: var(--bg);
  font-weight: 800;
  font-size: 11px;
  cursor: pointer;
}
.copy-wallet svg {
  width: 15px;
  height: 15px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
}
.wallet-card small {
  display: block;
  color: var(--muted-2);
  font-size: 9px;
  margin-top: 12px;
}
.site-footer {
  border-top: 1px solid var(--line);
  padding: 36px 0 55px;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  color: var(--muted);
  font-size: 11px;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--text);
  font-weight: 800;
}
.site-footer p {
  margin: 8px 0 0;
}
.footer-meta {
  display: flex;
  gap: 20px;
}
.footer-meta a {
  color: var(--text);
}
/* Course overview */
.course-hero {
  padding-block: 65px 80px;
}
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--muted-2);
  font: 600 10px/1 var(--mono);
  margin-bottom: 45px;
}
.breadcrumbs a:hover {
  color: var(--text);
}
.course-hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 70px;
  align-items: center;
}
.course-hero-copy h1 {
  font-size: clamp(54px, 7vw, 92px);
  line-height: 0.95;
  letter-spacing: -0.055em;
  margin: 0;
}
.course-hero-copy > p:not(.eyebrow) {
  color: var(--muted);
  font-size: 19px;
  max-width: 650px;
  margin: 25px 0 0;
}
.course-spec-card {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  background: linear-gradient(145deg, var(--surface), var(--bg-soft));
  padding: 28px;
}
.spec-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  margin-top: 50px;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}
.spec-grid div {
  padding: 18px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.spec-grid strong {
  display: block;
  font: 700 17px/1 var(--mono);
}
.spec-grid span {
  color: var(--muted);
  font-size: 10px;
}
.spec-line {
  display: flex;
  justify-content: space-between;
  padding-top: 18px;
  color: var(--muted);
  font-size: 11px;
}
.spec-line b {
  color: var(--accent);
}
.course-overview-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 70px;
  align-items: start;
}
.outcome-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px;
  background: var(--surface);
}
.outcome-card h3 {
  font-size: 24px;
  margin: 0 0 20px;
}
.outcome-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.outcome-card li {
  position: relative;
  padding: 11px 0 11px 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}
.outcome-card li:before {
  content: "";
  position: absolute;
  left: 2px;
  top: 19px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  border: 1px solid var(--accent);
}
.chapter-list {
  display: grid;
  gap: 12px;
}
.chapter-card {
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface);
  overflow: hidden;
}
.chapter-card[hidden] {
  display: none;
}
.chapter-card summary {
  list-style: none;
  display: grid;
  grid-template-columns: 56px 1fr auto 24px;
  align-items: center;
  gap: 18px;
  padding: 22px 24px;
  cursor: pointer;
}
.chapter-card summary::-webkit-details-marker {
  display: none;
}
.chapter-number {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 10px;
  font: 700 11px/1 var(--mono);
  color: var(--accent);
}
.chapter-card summary p {
  margin: 0;
  color: var(--muted-2);
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
}
.chapter-card summary h3 {
  font-size: 18px;
  margin: 5px 0 0;
}
.lesson-count {
  color: var(--muted);
  font-size: 11px;
}
.summary-chevron svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: var(--muted);
  stroke-width: 1.8;
  transition: transform 0.2s;
}
.chapter-card[open] .summary-chevron svg {
  transform: rotate(90deg);
}
.lesson-list {
  border-top: 1px solid var(--line);
  padding: 8px;
}
.lesson-row {
  display: grid;
  grid-template-columns: 38px 1fr auto;
  align-items: center;
  gap: 12px;
  min-height: 62px;
  padding: 8px 12px;
  border-radius: 10px;
}
.lesson-row:hover {
  background: var(--surface-2);
}
.lesson-row > span {
  color: var(--muted-2);
  font: 700 10px/1 var(--mono);
}
.lesson-row strong {
  display: block;
  font-size: 13px;
}
.lesson-row small {
  display: block;
  color: var(--muted-2);
  font-size: 10px;
  margin-top: 2px;
}
.lesson-row b {
  display: flex;
  align-items: center;
  gap: 7px;
  color: var(--muted-2);
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
}
.lesson-row.live {
  background: rgba(120, 245, 199, 0.035);
}
.lesson-row.live b {
  color: var(--accent);
}
/* Lesson layout */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 300;
  height: 2px;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 12px var(--accent);
}
.lesson-shell {
  width: min(100%, 1600px);
  margin: auto;
  display: grid;
  grid-template-columns: 290px minmax(0, 820px) 220px;
  gap: 42px;
  padding: 34px 28px 80px;
  align-items: start;
}
.course-sidebar,
.on-page-toc {
  position: sticky;
  top: 96px;
  max-height: calc(100vh - 116px);
}
.course-sidebar {
  border-right: 1px solid var(--line);
  padding-right: 22px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.sidebar-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}
.sidebar-head > a {
  display: flex;
  align-items: center;
  gap: 10px;
}
.sidebar-head small,
.sidebar-head strong {
  display: block;
}
.sidebar-head small {
  color: var(--muted-2);
  font: 700 9px/1 var(--mono);
}
.sidebar-head strong {
  font-size: 12px;
  margin-top: 4px;
}
.sidebar-head button {
  display: none;
  border: 0;
  background: transparent;
  font-size: 24px;
}
.sidebar-search {
  height: 40px;
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 0 10px;
  margin-bottom: 16px;
}
.sidebar-search input {
  font-size: 11px;
}
.sidebar-curriculum {
  overflow-y: auto;
  padding-right: 6px;
  scrollbar-width: thin;
}
.sidebar-chapter {
  border-top: 1px solid var(--line);
}
.sidebar-chapter summary {
  list-style: none;
  cursor: pointer;
  padding: 12px 2px;
  display: grid;
  grid-template-columns: 27px 1fr;
  gap: 7px;
  color: var(--muted);
  font-size: 10px;
  font-weight: 750;
  line-height: 1.4;
}
.sidebar-chapter summary::-webkit-details-marker {
  display: none;
}
.sidebar-chapter summary span {
  font: 700 9px/1.4 var(--mono);
  color: var(--muted-2);
}
.sidebar-lesson {
  display: grid;
  grid-template-columns: 25px 1fr auto;
  gap: 6px;
  padding: 8px;
  border-radius: 7px;
  color: var(--muted);
  font-size: 9.5px;
  line-height: 1.35;
}
.sidebar-lesson > span {
  font: 700 8px/1.35 var(--mono);
  color: var(--muted-2);
}
.sidebar-lesson i {
  font-style: normal;
  font-size: 7px;
  color: var(--muted-2);
}
.sidebar-lesson.is-current {
  background: rgba(120, 245, 199, 0.07);
  color: var(--text);
  border-left: 2px solid var(--accent);
}
.sidebar-lesson[hidden],
.sidebar-chapter[hidden] {
  display: none;
}
.lesson-article {
  min-width: 0;
}
.lesson-header {
  padding-bottom: 44px;
  border-bottom: 1px solid var(--line);
}
.lesson-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--accent);
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.lesson-meta i {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--line-strong);
}
.lesson-header h1 {
  font-size: clamp(42px, 5vw, 65px);
  line-height: 1.04;
  letter-spacing: -0.045em;
  margin: 18px 0;
}
.lesson-header > p {
  font-size: 18px;
  color: var(--muted);
  margin: 0;
}
.lesson-tags {
  display: flex;
  gap: 7px;
  margin-top: 24px;
}
.lesson-tags span,
.planned-label {
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  font: 700 8px/1 var(--mono);
  text-transform: uppercase;
}
.lesson-article > section {
  padding: 48px 0;
  border-bottom: 1px solid var(--line);
}
.lesson-article section h2 {
  font-size: 30px;
  line-height: 1.18;
  letter-spacing: -0.025em;
  margin: 0 0 18px;
}
.lesson-article section h3 {
  font-size: 19px;
  margin: 30px 0 10px;
}
.lesson-article section p {
  color: var(--muted);
  margin: 13px 0;
}
.lesson-article section strong {
  color: var(--text);
}
.lesson-article section code:not(pre code) {
  font: 600 0.88em/1.4 var(--mono);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 2px 5px;
  color: var(--accent-2);
}
.lesson-objectives {
  border: 1px solid rgba(120, 245, 199, 0.18) !important;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(120, 245, 199, 0.045), transparent);
  padding: 28px !important;
  margin-top: 45px;
}
.lesson-objectives ul {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 30px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}
.lesson-objectives li {
  position: relative;
  padding-left: 22px;
  color: var(--muted);
  font-size: 13px;
}
.lesson-objectives li:before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 800;
}
.concept-grid,
.option-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin: 25px 0;
}
.concept-grid article,
.option-cards article {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px;
  background: var(--surface);
}
.concept-grid span,
.option-cards span {
  color: var(--accent);
  font: 700 8px/1 var(--mono);
  text-transform: uppercase;
}
.concept-grid h3,
.option-cards h3 {
  margin: 22px 0 7px !important;
  font-size: 16px !important;
}
.concept-grid p,
.option-cards p {
  font-size: 11px;
  margin: 0 !important;
}
.option-cards {
  grid-template-columns: 1fr 1fr;
}
.diagram-card {
  margin: 28px 0;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface);
  overflow: hidden;
}
.diagram-label {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
}
.diagram-card .mermaid {
  padding: 24px;
  background: transparent;
}
.callout {
  border-left: 3px solid var(--accent-2);
  background: rgba(141, 162, 255, 0.055);
  border-radius: 0 10px 10px 0;
  padding: 16px 18px;
  margin: 24px 0;
}
.callout.warning {
  border-color: var(--warning);
  background: rgba(255, 212, 121, 0.055);
}
.callout p {
  margin: 4px 0 0 !important;
  font-size: 12px;
}
.workflow-list {
  display: grid;
  gap: 8px;
  margin: 24px 0;
}
.workflow-list > div {
  display: grid;
  grid-template-columns: 42px 150px 1fr;
  align-items: start;
  gap: 12px;
  border: 1px solid var(--line);
  border-radius: 11px;
  padding: 15px;
}
.workflow-list > div > span {
  font: 700 9px/1.5 var(--mono);
  color: var(--accent);
}
.workflow-list strong {
  font-size: 12px;
}
.workflow-list p {
  font-size: 11px;
  margin: 0 !important;
}
.definition-table {
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
}
.table-row {
  display: grid;
  grid-template-columns: 140px 1fr 180px;
  gap: 16px;
  padding: 13px 16px;
  border-top: 1px solid var(--line);
  align-items: center;
  font-size: 11px;
  color: var(--muted);
}
.table-row:first-child {
  border-top: 0;
}
.table-head {
  background: var(--surface-2);
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
  color: var(--muted-2);
}
.table-row code {
  overflow-wrap: anywhere;
}
.lesson-article pre {
  position: relative;
  margin: 24px 0;
  border: 1px solid var(--line) !important;
  border-radius: 14px;
  overflow: auto;
  background: var(--code-bg) !important;
  padding: 21px !important;
}
.lesson-article pre code {
  font: 500 12px/1.7 var(--mono) !important;
  background: transparent !important;
}
.code-copy {
  position: absolute;
  right: 8px;
  top: 8px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
  border-radius: 7px;
  padding: 5px 8px;
  font: 700 8px/1 var(--mono);
  cursor: pointer;
  z-index: 2;
}
.lab-checklist {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px;
  background: var(--surface);
}
.lab-checklist h3 {
  margin: 0 0 12px !important;
}
.lab-checklist label {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  padding: 8px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}
.lab-checklist input {
  accent-color: var(--accent);
  margin-top: 4px;
}
.mistake-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.mistake-list article {
  border: 1px solid var(--line);
  border-radius: 13px;
  padding: 18px;
}
.mistake-list h3 {
  font-size: 15px !important;
  margin: 0 0 6px !important;
}
.mistake-list p {
  font-size: 11px;
  margin: 0 !important;
}
.quiz-card {
  border: 1px solid var(--line);
  border-radius: 13px;
  padding: 18px;
  margin: 10px 0;
  background: var(--surface);
}
.quiz-card p {
  margin: 0 0 12px !important;
}
.quiz-card button {
  border: 1px solid var(--line-strong);
  background: var(--surface-2);
  border-radius: 7px;
  padding: 6px 9px;
  font-size: 9px;
  font-weight: 750;
  cursor: pointer;
}
.quiz-card div {
  margin-top: 13px;
  padding-top: 13px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}
.next-concepts {
  margin-top: 28px;
  border: 1px solid var(--line);
  border-radius: 15px;
  padding: 22px;
  background: linear-gradient(135deg, var(--surface), transparent);
}
.next-concepts > span:first-child {
  font: 700 8px/1 var(--mono);
  color: var(--accent);
  text-transform: uppercase;
}
.next-concepts h3 {
  margin: 14px 0 4px !important;
}
.next-concepts p {
  font-size: 12px;
  margin: 0 0 16px !important;
}
.reference-list {
  padding-left: 22px;
  color: var(--muted);
}
.reference-list li {
  padding: 5px 0;
}
.lesson-pagination {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 8px;
  padding: 30px 0;
}
.lesson-pagination > * {
  min-height: 46px;
  border: 1px solid var(--line);
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  font-size: 10px;
  font-weight: 700;
}
.lesson-pagination a:hover {
  color: var(--text);
  background: var(--surface);
}
.lesson-pagination .disabled {
  opacity: 0.45;
}
.lesson-article .support-panel {
  grid-template-columns: 1fr;
  margin-top: 50px;
  padding: 30px;
  gap: 25px;
}
.lesson-article .support-copy h2 {
  font-size: 27px;
}
.lesson-article .site-footer {
  padding-bottom: 10px;
}
.on-page-toc {
  padding-top: 8px;
}
.on-page-toc > p {
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
  color: var(--muted-2);
  letter-spacing: 0.08em;
}
.on-page-toc nav {
  display: grid;
  gap: 2px;
  margin-top: 14px;
}
.on-page-toc a {
  border-left: 1px solid var(--line);
  padding: 5px 0 5px 12px;
  color: var(--muted);
  font-size: 9.5px;
  line-height: 1.35;
}
.on-page-toc a.is-active {
  color: var(--text);
  border-color: var(--accent);
}
.toc-progress {
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  color: var(--muted-2);
  font: 700 8px/1 var(--mono);
}
.toc-progress strong {
  color: var(--accent);
}
.course-drawer-button {
  display: none;
  position: fixed;
  bottom: 18px;
  left: 18px;
  z-index: 80;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--text);
  color: var(--bg);
  padding: 10px 14px;
  font-size: 10px;
  font-weight: 800;
  box-shadow: var(--shadow);
}
/* Utility */
.utility-main {
  min-height: 72vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 20px;
}
.error-code {
  font: 800 clamp(100px, 22vw, 260px)/0.8 var(--mono);
  letter-spacing: -0.1em;
  color: transparent;
  -webkit-text-stroke: 1px var(--line-strong);
  opacity: 0.7;
}
.utility-main h1 {
  font-size: 46px;
  letter-spacing: -0.04em;
  margin: 12px 0;
}
.utility-main > p:not(.eyebrow) {
  max-width: 600px;
  color: var(--muted);
}
@media (max-width: 1120px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
  }
  .hero-console {
    max-width: 680px;
  }
  .course-grid {
    grid-template-columns: 1fr 1fr;
  }
  .method-grid {
    grid-template-columns: 1fr 1fr;
  }
  .lesson-shell {
    grid-template-columns: minmax(0, 820px) 210px;
    max-width: 1100px;
  }
  .course-sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    z-index: 220;
    width: 310px;
    max-height: none;
    background: var(--bg);
    padding: 22px;
    transform: translateX(-105%);
    transition: transform 0.25s;
    box-shadow: var(--shadow);
  }
  .course-sidebar.is-open {
    transform: none;
  }
  .sidebar-head button,
  .course-drawer-button {
    display: block;
  }
  .lesson-shell:after {
    content: "";
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.55);
    z-index: 210;
    opacity: 0;
    pointer-events: none;
    transition: 0.25s;
  }
  .lesson-shell.sidebar-open:after {
    opacity: 1;
    pointer-events: auto;
  }
}
@media (max-width: 820px) {
  .section-shell,
  .header-inner {
    width: min(calc(100% - 28px), var(--max));
  }
  .desktop-nav,
  .desktop-only {
    display: none;
  }
  .mobile-menu-button {
    display: grid;
  }
  .mobile-nav.is-open {
    display: grid;
  }
  .hero {
    padding-block: 54px;
    grid-template-columns: 1fr;
    gap: 45px;
  }
  .hero h1 {
    font-size: 50px;
  }
  .hero-lead {
    font-size: 16px;
  }
  .hero-stats {
    grid-template-columns: 1fr 1fr;
  }
  .trust-strip {
    overflow: hidden;
    justify-content: flex-start;
    gap: 24px;
  }
  .section-block {
    padding-block: 78px;
  }
  .section-heading.split,
  .course-hero-grid,
  .course-overview-grid,
  .support-panel {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .course-grid,
  .active-course-grid {
    grid-template-columns: 1fr;
  }
  .filter-toggle {
    display: block;
    border: 1px solid var(--line);
    background: var(--surface);
    border-radius: 10px;
    padding: 0 12px;
    font-size: 11px;
  }
  .filter-row {
    display: none;
  }
  .filter-row.is-open {
    display: flex;
  }
  .method-grid {
    grid-template-columns: 1fr;
  }
  .support-panel {
    padding: 30px;
  }
  .site-footer {
    align-items: flex-start;
    gap: 24px;
    flex-direction: column;
  }
  .chapter-card summary {
    grid-template-columns: 46px 1fr 20px;
  }
  .lesson-count {
    display: none;
  }
  .lesson-shell {
    display: block;
    padding: 24px 18px 60px;
  }
  .on-page-toc {
    display: none;
  }
  .lesson-objectives ul {
    grid-template-columns: 1fr;
  }
  .concept-grid,
  .option-cards,
  .mistake-list {
    grid-template-columns: 1fr;
  }
  .workflow-list > div {
    grid-template-columns: 32px 1fr;
  }
  .workflow-list p {
    grid-column: 2;
  }
  .table-row {
    grid-template-columns: 100px 1fr;
  }
  .table-row > *:last-child {
    grid-column: 2;
  }
  .lesson-pagination {
    grid-template-columns: 1fr;
  }
  .lesson-article .support-panel {
    grid-template-columns: 1fr;
  }
  .course-drawer-button {
    display: block;
  }
}
@media (max-width: 540px) {
  .hero h1 {
    font-size: 43px;
  }
  .hero-stats {
    grid-template-columns: 1fr 1fr;
  }
  .console-body {
    padding: 20px 14px;
  }
  .console-step {
    grid-template-columns: 28px 1fr;
  }
  .console-step b {
    display: none;
  }
  .section-heading h2,
  .overview-copy h2 {
    font-size: 36px;
  }
  .course-hero-copy h1 {
    font-size: 50px;
  }
  .active-course {
    grid-template-columns: auto 1fr;
    padding: 22px;
  }
  .active-course > svg {
    display: none;
  }
  .large-glyph {
    width: 60px;
    height: 60px;
  }
  .course-card {
    min-height: 290px;
  }
  .support-copy h2 {
    font-size: 29px;
  }
  .wallet-card code {
    font-size: 9px;
  }
  .footer-meta {
    flex-direction: column;
    gap: 4px;
  }
  .lesson-header h1 {
    font-size: 40px;
  }
  .lesson-header > p {
    font-size: 16px;
  }
  .lesson-article section h2 {
    font-size: 26px;
  }
}
@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    animation: none !important;
    transition: none !important;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* Theme-toggle reliability */
.header-actions {
  flex: 0 0 auto;
}
.icon-button {
  flex: 0 0 38px;
  min-width: 38px;
  overflow: visible;
}
.header-actions [data-theme-toggle] {
  display: grid !important;
  visibility: visible !important;
  opacity: 1 !important;
  position: relative;
  z-index: 2;
}
.header-actions [data-theme-toggle] svg {
  display: block !important;
  visibility: visible !important;
  opacity: 1 !important;
  color: var(--text);
}
.header-actions [data-theme-toggle][data-theme-state="light"] svg path {
  fill: currentColor;
  stroke: none;
}
.header-actions [data-theme-toggle][data-theme-state="dark"] svg path {
  fill: none;
  stroke: currentColor;
}
.brand {
  min-width: 0;
}
.brand-copy {
  min-width: 0;
}

/* Theme-aware Mermaid diagrams */
.diagram-card .mermaid {
  transition: opacity 0.18s ease;
}
.diagram-card .mermaid[aria-busy="true"] {
  opacity: 0.45;
}
.diagram-card .mermaid svg {
  display: block;
  max-width: 100%;
  height: auto;
  margin-inline: auto;
}
.diagram-card .mermaid .edgeLabel,
.diagram-card .mermaid .label {
  color: var(--text) !important;
}

/* Mermaid SVG and transparent 4x PNG export controls */
.devops-mermaid-export-host {
  position: relative !important;
}
.diagram-card.devops-mermaid-export-host > .diagram-label {
  min-height: 55px;
  display: flex;
  align-items: center;
  padding-right: 190px;
}
.devops-mermaid-export-controls {
  position: absolute;
  top: 8px;
  right: 10px;
  z-index: 20;
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 7px;
  pointer-events: auto;
}
.devops-mermaid-export-btn {
  box-sizing: border-box;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-width: 72px;
  height: 38px;
  margin: 0;
  padding: 0 11px;
  border: 1px solid var(--line-strong);
  border-radius: 9px;
  color: var(--text);
  background: var(--surface-2);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.18);
  font: 800 9px/1 var(--mono);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  cursor: pointer;
  transition:
    color 0.16s,
    border-color 0.16s,
    background 0.16s,
    transform 0.16s,
    opacity 0.16s;
}
.devops-mermaid-export-btn:hover {
  border-color: var(--accent);
  background: var(--surface-3);
  transform: translateY(-1px);
}
.devops-mermaid-export-btn:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 55%, transparent);
  outline-offset: 2px;
}
.devops-mermaid-export-btn:disabled,
.devops-mermaid-export-btn.is-busy {
  cursor: wait;
  opacity: 0.48;
  transform: none;
}
.devops-mermaid-export-btn.is-success {
  color: #0d5138;
  border-color: rgba(24, 150, 101, 0.55);
  background: #e9fbf3;
}
html[data-theme="dark"] .devops-mermaid-export-btn.is-success {
  color: #bff8de;
  border-color: rgba(120, 245, 199, 0.5);
  background: #123528;
}
.devops-mermaid-export-btn.is-error {
  color: #8b2635;
  border-color: rgba(220, 70, 90, 0.5);
  background: #fff0f2;
}
html[data-theme="dark"] .devops-mermaid-export-btn.is-error {
  color: #ffd2d8;
  border-color: rgba(255, 138, 154, 0.52);
  background: #412029;
}
.devops-mermaid-export-btn__icon {
  font-size: 15px;
  line-height: 1;
  transform: translateY(-1px);
}
.devops-mermaid-export-frame {
  position: relative;
  box-sizing: border-box;
  width: 100%;
  padding-top: 54px;
}

@media (max-width: 820px) {
  .header-inner {
    gap: 10px;
  }
  .header-actions {
    gap: 6px;
  }
  .brand-copy strong {
    white-space: nowrap;
  }
  .icon-button {
    flex-basis: 38px;
  }
}
@media (max-width: 600px) {
  .diagram-card.devops-mermaid-export-host > .diagram-label {
    min-height: auto;
    padding-right: 16px;
  }
  .devops-mermaid-export-controls {
    position: static;
    display: flex;
    padding: 10px 12px;
    border-bottom: 1px solid var(--line);
    background: var(--surface-2);
  }
  .devops-mermaid-export-btn {
    min-width: 66px;
    height: 34px;
    padding: 0 9px;
    font-size: 8px;
  }
  .devops-mermaid-export-frame {
    padding-top: 0;
  }
  .devops-mermaid-export-frame > .devops-mermaid-export-controls {
    position: static;
  }
}
@media (max-width: 540px) {
  .brand-copy small {
    display: none;
  }
  .header-actions [data-theme-toggle],
  .mobile-menu-button {
    width: 36px;
    height: 36px;
    min-width: 36px;
    flex-basis: 36px;
  }
  .header-actions [data-theme-toggle] svg {
    width: 17px;
    height: 17px;
  }
}
@media (max-width: 390px) {
  .brand-copy strong {
    font-size: 12px;
  }
  .brand-mark {
    width: 36px;
    height: 36px;
  }
  .header-inner {
    width: min(calc(100% - 20px), var(--max));
  }
}

/* Responsive navigation icon visibility. The generic filled-icon rule is
   intended for logo glyphs; the hamburger is a stroked open path. */
.mobile-menu-button {
  color: var(--text);
  flex: 0 0 38px;
}
.mobile-menu-button svg,
.mobile-menu-button svg path {
  fill: none !important;
  stroke: currentColor !important;
  stroke-width: 1.8 !important;
  stroke-linecap: round !important;
  stroke-linejoin: round !important;
  opacity: 1 !important;
  visibility: visible !important;
}
@media (max-width: 540px) {
  .mobile-menu-button {
    flex-basis: 36px;
  }
}
/* ==========================================================================
   Lesson readability improvements
   - Justify lesson-body paragraphs
   - Increase left/right lesson sidebar typography by 2px
   ========================================================================== */

/* --------------------------------------------------------------------------
   Main lesson content: justify paragraph text
   -------------------------------------------------------------------------- */
.lesson-article > section:not(.support-panel) p {
  text-align: justify;
  text-justify: inter-word;
}

/* --------------------------------------------------------------------------
   Left sidebar: +2px typography
   -------------------------------------------------------------------------- */

/* Course number / small heading */
.course-sidebar .sidebar-head small {
  font-size: 11px; /* was 9px */
}

/* Course title */
.course-sidebar .sidebar-head strong {
  font-size: 14px; /* was 12px */
}

/* Course glyph, e.g. LIN / PS */
.course-sidebar .course-glyph {
  font-size: 12px; /* was 10px */
}

/* Search field */
.course-sidebar .sidebar-search input {
  font-size: 13px; /* was 11px */
}

/* Chapter titles */
.course-sidebar .sidebar-chapter summary {
  font-size: 12px; /* was 10px */
}

/* Chapter numbers */
.course-sidebar .sidebar-chapter summary span {
  font-size: 11px; /* was 9px */
}

/* Lesson titles */
.course-sidebar .sidebar-lesson {
  font-size: 11.5px; /* was 9.5px */
}

/* Lesson numbers */
.course-sidebar .sidebar-lesson > span {
  font-size: 10px; /* was 8px */
}

/* Any small lesson-side metadata */
.course-sidebar .sidebar-lesson i {
  font-size: 9px; /* was 7px */
}

/* --------------------------------------------------------------------------
   Right sidebar / "On this page": +2px typography
   -------------------------------------------------------------------------- */

/* "ON THIS PAGE" heading */
.on-page-toc > p {
  font-size: 11px; /* was 9px */
}

/* Section links */
.on-page-toc a {
  font-size: 11.5px; /* was 9.5px */
}

/* Lesson progress text */
.on-page-toc .toc-progress {
  font-size: 10px; /* was 8px */
}

/* ==========================================================================
   Right sidebar: keep lesson progress visible
   ========================================================================== */

.on-page-toc {
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 116px);
  padding-bottom: 20px;
}

/* Allow only the section-link list to scroll when it becomes too tall */
.on-page-toc nav {
  min-height: 0;
  overflow-y: auto;
  padding-bottom: 12px;
  scrollbar-width: thin;
}

/* Keep the progress indicator visible at the bottom */
.on-page-toc .toc-progress {
  flex: 0 0 auto;
  margin-top: 14px;
  padding: 16px 0 8px;
  background: var(--bg);
  position: relative;
  z-index: 2;
}