@import 'tailwindcss';
@import 'tw-animate-css';
@import 'shadcn/tailwind.css';
@custom-variant dark (&:is(.dark *));
@theme inline {
  --color-background: var(--background);
  --color-foreground: var(--foreground);
  --color-card: var(--card);
  --color-card-foreground: var(--foreground);
  --color-popover: var(--background);
  --color-popover-foreground: var(--foreground);
  --color-primary: var(--primary);
  --color-primary-foreground: #fff;
  --color-secondary: var(--muted);
  --color-secondary-foreground: var(--foreground);
  --color-muted: var(--muted);
  --color-muted-foreground: var(--muted-foreground);
  --color-accent: var(--accent);
  --color-accent-foreground: var(--primary);
  --color-destructive: #b74435;
  --color-border: var(--border);
  --color-input: var(--border);
  --color-ring: var(--primary);
  --color-sidebar: var(--sidebar);
  --color-sidebar-foreground: var(--foreground);
  --color-sidebar-primary: var(--primary);
  --color-sidebar-primary-foreground: #fff;
  --color-sidebar-accent: var(--accent);
  --color-sidebar-accent-foreground: var(--primary);
  --color-sidebar-border: var(--border);
  --color-sidebar-ring: var(--primary);
  --font-sans: var(--font-geist-sans);
  --font-mono: var(--font-geist-mono);
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
}
:root {
  --background: #fff;
  --foreground: #111827;
  --card: #fff;
  --primary: #2f6bff;
  --muted: #f3f6fb;
  --muted-foreground: #667085;
  --accent: #edf4ff;
  --border: #e6ebf3;
  --sidebar: #f8fafc;
  --radius: 8px;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 98px;
}
body {
  margin: 0;
  font-family:
    var(--font-geist-sans), 'Microsoft YaHei', 'PingFang SC', sans-serif;
  color: var(--foreground);
  background: var(--background);
  font-size: 16px;
  line-height: 1.75;
}
a {
  color: inherit;
  text-decoration: none;
}
button,
input,
select,
textarea {
  font: inherit;
}
button,
a {
  -webkit-tap-highlight-color: transparent;
}
button:not(:disabled),
summary {
  cursor: pointer;
}
button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}
button:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 4px;
}
p {
  margin: 0 0 1em;
}
h1,
h2,
h3,
h4 {
  font-weight: 600;
  letter-spacing: -0.03em;
}
h1 {
  font-size: 44px;
  line-height: 1.3;
  margin: 13px 0 20px;
}
h2 {
  font-size: 24px;
  line-height: 1.45;
  margin: 0;
}
h3 {
  font-size: 17px;
  margin: 0 0 7px;
  line-height: 1.5;
}
h4 {
  font-size: 16px;
  margin: 0 0 5px;
}
code,
pre,
.mono {
  font-family: var(--font-geist-mono), Consolas, monospace;
}
p code,
li code {
  font-size: 0.88em;
  padding: 2px 5px;
  background: var(--muted);
  border: 1px solid var(--border);
  border-radius: 4px;
}
section {
  scroll-margin-top: 85px;
  margin: 42px 0;
}
svg {
  flex-shrink: 0;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 23px 16px 29px;
  font-size: 17px;
  font-weight: 650;
  line-height: 1.45;
}
.brand-symbol {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: #25375a;
  color: #fff;
  display: grid;
  place-items: center;
}
.brand-sub {
  display: block;
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 1px;
  color: #69758e;
  margin-top: 4px;
}
.nav-caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: #707d96;
  padding: 6px 25px 16px;
}
.nav-caption span {
  font-family: var(--font-geist-mono);
  font-size: 10px;
  letter-spacing: 0.7px;
}
.module-nav {
  padding: 0 12px;
}
.module-link {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 11px 13px;
  margin: 3px 0;
  border-radius: 6px;
  font-size: 14px;
  color: #586378;
  text-align: left;
  background: transparent;
  border: 0;
}
.module-link:hover {
  background: #edeef1;
}
.module-link.selected {
  background: #e5e9f0;
  color: #273a5f;
  font-weight: 600;
}
.module-link > span:nth-child(2) {
  flex: 1;
}
.nav-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--primary);
}
.soon {
  font-size: 11px;
  color: #707c95;
  font-weight: 400;
}
.sidebar-note {
  display: flex;
  gap: 11px;
  align-items: flex-start;
  color: #4f596c;
  padding: 19px 15px;
  font-size: 13px;
  border-top: 1px solid var(--border);
}
.sidebar-note small {
  display: block;
  color: #7c889f;
  margin-top: 4px;
  font-size: 12px;
}
.workspace {
  min-width: 0;
  flex: 1;
}
.interview-followups {
  margin-top: 22px;
}
.topbar {
  height: 69px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 44px;
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.96);
  z-index: 20;
  gap: 20px;
}
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 15px;
  font-size: 13px;
  color: #6d7a93;
  min-width: 0;
}
.breadcrumbs strong {
  font-weight: 500;
  color: #414958;
}
.quiet-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 13px;
  color: #5d687d;
  white-space: nowrap;
}
.quiet-link:hover {
  color: var(--primary);
}
.document-grid {
  display: grid;
  grid-template-columns: minmax(0, 860px) 160px;
  gap: 55px;
  max-width: 1210px;
  margin: auto;
  padding: 49px 48px 70px;
}
.document-grid > main {
  min-width: 0;
}
.document-grid.document-grid-home {
  grid-template-columns: minmax(0, 1fr);
  max-width: 1360px;
  gap: 26px;
}
.document-grid-home > .toc {
  display: flex;
  grid-row: 1;
  flex-wrap: wrap;
  align-items: center;
  position: static;
  gap: 6px 24px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border);
}
.document-grid-home > .toc > p {
  margin: 0;
}
.document-grid-home > .toc > a {
  padding: 4px 0;
  margin: 0;
  border: 0;
}
.document-grid-home > .toc .toc-note {
  display: none;
}
.eyebrow {
  display: flex;
  align-items: center;
  gap: 11px;
  font-size: 11px;
  letter-spacing: 1.4px;
  color: #5f6a81;
  font-family: var(--font-geist-mono), 'Microsoft YaHei', sans-serif;
}
.eyebrow span {
  width: 17px;
  height: 1px;
  background: #9da5b6;
}
.title-dot {
  color: var(--primary);
  margin-left: 3px;
}
.lead {
  color: #5b667c;
  font-size: 17px;
  line-height: 1.9;
  margin-bottom: 22px;
}
.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  font-size: 12px;
  color: #69768f;
}
.meta-row > span {
  display: flex;
  align-items: center;
  gap: 6px;
}
.meta-row > span + span:before {
  content: '';
  width: 3px;
  height: 3px;
  background: #a6aebd;
  margin-right: 7px;
  border-radius: 50%;
}
.module-intro {
  display: flex;
  gap: 24px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
  margin-top: 30px;
}
.module-intro p {
  font-size: 14px;
  color: #636e85;
  margin: 0;
  line-height: 1.85;
}
.section-index {
  white-space: nowrap;
  color: var(--primary);
  font-size: 13px;
  font-family: var(--font-geist-mono);
  padding-top: 2px;
}
.section-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 19px;
}
.section-heading > span {
  color: #7d889f;
  font-size: 12px;
}
.path-row {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 21px 2px;
  border-bottom: 1px solid var(--border);
}
.path-row > div {
  flex: 1;
}
.path-row p {
  font-size: 14px;
  color: #6c7891;
  margin: 0;
}
.path-row svg {
  color: #858fa4;
}
.path-row:hover h3 {
  color: var(--primary);
}
.path-number {
  color: #76829a;
  font-size: 13px;
  font-family: var(--font-geist-mono);
}
.toc {
  font-size: 13px;
  position: sticky;
  top: 111px;
  align-self: start;
  padding-top: 4px;
  color: #6d7a93;
}
.toc > p {
  font-size: 12px;
  color: #3e4554;
  margin-bottom: 15px;
}
.toc > a {
  display: block;
  border-left: 1px solid var(--border);
  padding: 7px 0 7px 15px;
}
.toc > a:hover {
  color: var(--primary);
  border-color: var(--primary);
}
.toc-note {
  margin-top: 35px;
  padding-top: 22px;
  border-top: 1px solid var(--border);
  font-size: 12px;
  line-height: 2;
}
.toc-note p {
  margin-top: 12px;
}
.tiny-label {
  font-size: 11px;
  letter-spacing: 1px;
  color: #808ba1;
}
.code {
  font-size: 13px;
  line-height: 1.85;
  padding: 22px 24px;
  background: #f5f6f7;
  color: #2e3749;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: auto;
  tab-size: 4;
  white-space: pre;
  margin: 15px 0 23px;
}
.code code {
  font: inherit;
}
@media (min-width: 1440px) {
  .document-grid {
    padding-top: 60px;
    gap: 70px;
  }
  .topbar {
    padding: 0 52px;
  }
}
@media (max-width: 1200px) {
  .toc {
    display: none;
  }
  .document-grid {
    grid-template-columns: minmax(0, 1fr);
    padding: 38px 38px 60px;
    max-width: 920px;
  }
  .topbar {
    padding: 0 32px;
  }
}
@media (max-width: 767px) {
  .document-grid {
    padding: 30px 23px 60px;
  }
  .topbar {
    padding: 0 17px;
    height: 60px;
  }
  .quiet-link {
    font-size: 12px;
  }
  .breadcrumbs {
    gap: 9px;
    font-size: 12px;
  }
  h1 {
    font-size: 33px;
  }
  h2 {
    font-size: 22px;
  }
  .lead {
    font-size: 16px;
  }
  .module-intro {
    gap: 16px;
  }
  .path-row {
    gap: 16px;
  }
  .section-heading {
    align-items: flex-start;
  }
  .section-heading > span {
    max-width: 125px;
    text-align: right;
  }
  .meta-row {
    font-size: 11px;
    gap: 8px 11px;
  }
}
.skip-link {
  position: fixed;
  top: -80px;
  left: 20px;
  padding: 10px 20px;
  background: var(--primary);
  color: white;
  z-index: 100;
  border-radius: 6px;
}
.skip-link:focus {
  top: 12px;
}
h1:focus {
  outline: none;
}
.topbar-actions {
  display: flex;
  align-items: center;
  gap: 23px;
}
.topbar-actions button {
  font-size: 12px;
  color: #586276;
}
.overview-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 27px;
}
.primary-link,
.secondary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border-radius: 6px;
  padding: 9px 15px;
  font-size: 13px;
  line-height: 1.6;
  transition: background 0.16s;
}
.primary-link {
  background: var(--primary);
  color: #fff;
  border: 1px solid var(--primary);
}
.primary-link:hover {
  background: #1f2e4c;
}
.secondary-link {
  background: #fff;
  color: #535d70;
  border: 1px solid var(--border);
}
.secondary-link:hover {
  background: #f2f3f6;
}
.material-state {
  font-size: 11px;
  color: #7c889f;
  margin-left: 3px;
}
.phase {
  margin: 23px 0 29px;
}
.phase-heading {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 13px 16px;
  background: #f4f5f7;
  border: 1px solid var(--border);
  border-radius: 7px;
}
.phase-heading > div {
  flex: 1;
}
.phase-heading h3 {
  font-size: 15px;
  margin: 0 0 3px;
}
.phase-heading p {
  font-size: 12px;
  color: #6d7a93;
  margin: 0;
}
.phase-marker {
  font-size: 16px;
  color: #7e89a0;
  font-family: var(--font-geist-mono);
  align-self: flex-start;
  line-height: 1.6;
}
.phase-range {
  font-size: 11px;
  color: #828da3;
  white-space: nowrap;
  font-family: var(--font-geist-mono);
}
.lesson-rows {
  padding-left: 13px;
}
.lesson-row {
  display: flex;
  gap: 15px;
  align-items: center;
  padding: 17px 8px;
  border-bottom: 1px solid #eceef1;
}
.lesson-row > div {
  flex: 1;
  min-width: 0;
}
.lesson-row strong {
  font-size: 14px;
  font-weight: 500;
  display: block;
  line-height: 1.6;
}
.lesson-row p {
  font-size: 12px;
  margin: 4px 0 0;
  color: #707c95;
  line-height: 1.65;
}
.lesson-number {
  color: #8c96aa;
  font-family: var(--font-geist-mono);
  font-size: 12px;
  min-width: 22px;
}
.lesson-row:hover {
  background: #fbfcfd;
}
.lesson-row:hover strong {
  color: var(--primary);
}
.lesson-row > svg {
  color: #949db0;
}
.lesson-duration {
  font-size: 11px;
  white-space: nowrap;
  color: #7c889f;
}
.interactive-badge {
  border: 1px solid #d8dde7;
  border-radius: 4px;
  background: #f7f8fb;
  color: #5d6d8d;
  font-size: 10px;
  padding: 0 5px;
  white-space: nowrap;
}
.section-caption {
  font-size: 13px;
  color: #67738c;
  line-height: 1.8;
  margin-top: 16px;
}
.api-table {
  margin: 22px 0;
  font-size: 13px;
}
.api-table th {
  color: #737f97;
  font-size: 12px;
  font-weight: 400;
  background: #f7f8f9;
}
.api-table td {
  padding: 13px 10px;
  white-space: normal;
  color: #515a6d;
  font-size: 13px;
  line-height: 1.8;
}
.api-table th:last-child,
.api-table td:last-child {
  white-space: nowrap;
}
.api-table code {
  font-size: 11px;
  color: #354669;
}
.resource-strip {
  padding: 23px;
  display: flex;
  align-items: center;
  gap: 16px;
  background: #f7f8fa;
  border: 1px solid var(--border);
  border-radius: 7px;
  margin-top: 20px;
  color: #545e72;
}
.resource-strip > div {
  flex: 1;
}
.resource-strip h3 {
  font-size: 15px;
}
.resource-strip p {
  font-size: 12px;
  margin: 0;
  color: #707d96;
}
.resource-strip a {
  white-space: nowrap;
  font-size: 12px;
}
.check-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.check-list li {
  display: flex;
  gap: 13px;
  padding: 10px 0;
  font-size: 15px;
  line-height: 1.85;
}
.check-list svg {
  margin-top: 6px;
  color: var(--primary);
}
.next-module {
  border-top: 1px solid var(--border);
  padding-top: 25px;
  margin-top: 35px;
  display: flex;
  gap: 14px;
  align-items: center;
  font-size: 13px;
}
.next-module > span:first-child {
  color: #77839a;
  font-size: 12px;
}
.next-module strong {
  font-weight: 500;
}
.next-module .soon {
  margin-left: auto;
}
.page-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  font-size: 11px;
  color: #808ba1;
  margin: 0 44px;
  padding: 21px 0;
  border-top: 1px solid var(--border);
}
.toc-download {
  display: flex !important;
  align-items: center;
  gap: 8px;
  border: 0 !important;
  padding-left: 0 !important;
  color: #52607c !important;
  margin-top: 15px;
}
.pending-module {
  min-height: 67vh;
  padding: 20px 0;
}
.pending-module .status-label {
  display: inline-block;
  margin: 8px 0 25px;
}
.pending-module .lead {
  margin-bottom: 32px;
}
.status-label {
  font-size: 11px;
  color: #67738c;
  background: #eef0f3;
  border: 1px solid #e2e4e9;
  padding: 3px 8px;
  border-radius: 4px;
  white-space: nowrap;
}
.lesson-nav {
  margin: 18px 0 10px;
  padding-top: 22px;
  border-top: 1px solid var(--border);
}
.lesson-nav .nav-caption {
  padding-bottom: 6px;
}
.lesson-nav-group {
  font-size: 11px;
  color: #828da2;
  padding: 15px 24px 7px;
  margin: 0;
}
.lesson-nav-link {
  display: flex;
  gap: 9px;
  padding: 8px 15px 8px 24px;
  font-size: 12px;
  color: #657189;
  line-height: 1.6;
  border-left: 2px solid transparent;
}
.lesson-nav-link span {
  font-family: var(--font-geist-mono);
  font-size: 10px;
  color: #97a0b2;
  padding-top: 2px;
}
.lesson-nav-link.current {
  color: var(--primary);
  background: #edeff4;
  border-left-color: var(--primary);
}
.lesson-nav-link:hover {
  color: var(--primary);
  background: #edeff4;
}
.back-link {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 12px;
  color: #6f7c95;
  margin-bottom: 26px;
  width: fit-content;
}
.back-link:hover {
  color: var(--primary);
}
.lesson-title {
  font-size: 35px;
  margin-top: 15px;
  line-height: 1.5;
}
.lesson-article > .lead {
  font-size: 16px;
}
.objectives {
  background: #f4f5f8;
  border-left: 3px solid #a7b1c5;
  padding: 21px 23px;
  margin: 29px 0 18px;
  border-radius: 0 6px 6px 0;
}
.objectives h2 {
  font-size: 15px;
  margin-bottom: 12px;
}
.objectives ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.objectives li {
  display: flex;
  gap: 12px;
  font-size: 14px;
  line-height: 1.8;
  padding: 5px 0;
}
.objectives li span {
  color: #818da4;
  font-size: 11px;
  font-family: var(--font-geist-mono);
  padding-top: 3px;
}
.video-section {
  margin: 18px 0 37px;
}
.video-pending {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 23px 20px;
  border: 1px solid var(--border);
  border-radius: 7px;
  color: #7c879e;
  background: #fafbfc;
}
.video-pending > div {
  flex: 1;
}
.video-pending strong {
  display: block;
  font-weight: 500;
  font-size: 14px;
  color: #616c83;
}
.video-pending div span {
  display: block;
  font-size: 12px;
  margin-top: 5px;
  color: #8b95aa;
}
.video-player video {
  width: 100%;
  aspect-ratio: 16/9;
  background: #181e29;
  border-radius: 8px;
}
.video-player > a {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 12px;
  margin-top: 8px;
  color: var(--primary);
}
.concept {
  margin: 23px 0 26px;
}
.concept h3 {
  display: flex;
  gap: 9px;
  font-size: 17px;
}
.concept h3 > span {
  color: #8a94a9;
  font-size: 14px;
  padding-top: 2px;
}
.concept p,
.practice-step > p {
  font-size: 15px;
  line-height: 1.95;
  color: #576175;
  white-space: pre-line;
  overflow-wrap: anywhere;
}
.practice-step {
  margin: 26px 0 34px;
}
.lesson-start {
  margin: 30px 0;
}
.lesson-start h2 {
  margin-bottom: 16px;
}
.lesson-start h3 {
  margin: 22px 0 10px;
  font-size: 15px;
}
.lesson-scenario,
.lesson-start li,
.lesson-outcome p,
.step-observation p,
.step-explanation p {
  font-size: 15px;
  line-height: 1.95;
  color: #45536a;
  white-space: pre-line;
  overflow-wrap: anywhere;
}
.lesson-start ul {
  padding-left: 21px;
}
.lesson-start li + li {
  margin-top: 8px;
}
.lesson-start-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.8;
  color: #2559df;
}
.lesson-start-link svg {
  flex-shrink: 0;
}
.lesson-start-link:hover {
  text-decoration: underline;
}
.lesson-outcome {
  border-left: 3px solid #2f6bff;
  padding: 2px 0 2px 16px;
  margin: 20px 0;
}
.lesson-outcome > span {
  font-size: 12px;
  font-weight: 600;
  color: #2559df;
}
.lesson-outcome p {
  margin: 5px 0 0;
}
.lesson-reading-guide,
.learning-section-note {
  font-size: 14px;
  line-height: 1.85;
  color: #637088;
}
.lesson-reading-guide {
  border-top: 1px solid #e6ebf3;
  margin-top: 20px;
  padding-top: 15px;
}
.step-observation,
.step-explanation {
  margin-top: 16px;
  padding: 13px 17px;
  border-left: 3px solid #93b9a3;
}
.step-observation {
  background: #f4f9f6;
}
.step-explanation {
  border-left-color: #b7c9eb;
}
.step-observation h4,
.step-explanation h4 {
  margin: 0 0 5px;
  font-size: 13px;
  line-height: 1.6;
  font-weight: 600;
  color: #286146;
}
.step-explanation h4 {
  color: #365789;
}
.step-observation p,
.step-explanation p {
  margin: 0;
}
.lesson-recap {
  border-top: 2px solid #dce6f6;
  padding-top: 28px;
}
.practice-title {
  display: flex;
  align-items: flex-start;
  gap: 13px;
  margin: 15px 0 12px;
}
.practice-title > span {
  font-family: var(--font-geist-mono);
  font-size: 12px;
  width: 27px;
  height: 27px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  border: 1px solid #dce0e8;
  background: #f5f7fa;
  border-radius: 5px;
  color: #5f6b84;
}
.practice-title h3 {
  margin: 0;
  padding-top: 1px;
  font-size: 17px;
}
.code-block {
  border: 1px solid #dfe2e7;
  background: #f7f8f9;
  border-radius: 8px;
  overflow: hidden;
  margin: 18px 0 25px;
}
.code-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 15px;
  border-bottom: 1px solid #e5e7ec;
  background: #f0f1f4;
  font-size: 12px;
  color: #68748c;
}
.code-toolbar > span {
  display: flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-geist-mono);
}
.copy-button {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  color: #667289;
  background: transparent;
  border: 0;
  padding: 0 4px;
}
.copy-button:hover {
  color: var(--primary);
}
.code-block pre {
  font-size: 12px;
  line-height: 1.9;
  overflow: auto;
  margin: 0;
  padding: 19px 21px 21px 0;
  color: #363e4d;
  tab-size: 4;
}
.code-line {
  white-space: pre;
}
.line-number {
  display: inline-block;
  min-width: 46px;
  padding: 0 13px 0 8px;
  text-align: right;
  user-select: none;
  pointer-events: none;
  color: #aab2c1;
  font-size: 11px;
}
.syntax-string {
  color: #475778;
}
.syntax-keyword {
  color: #247081;
  font-weight: 500;
}
.syntax-comment {
  color: #8c96aa;
}
.pitfall {
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}
.pitfall:first-child {
  padding-top: 4px;
}
.pitfall h3 {
  font-size: 16px;
  margin-bottom: 12px;
}
.pitfall p {
  display: flex;
  gap: 13px;
  font-size: 14px;
  color: #66728a;
  line-height: 1.9;
  margin-bottom: 7px;
  white-space: pre-line;
}
.pitfall p strong {
  font-size: 11px;
  font-weight: 400;
  background: #f0f1f4;
  padding: 2px 5px;
  color: #748099;
  flex-shrink: 0;
  align-self: flex-start;
  border-radius: 3px;
}
.exercise {
  padding: 26px;
  border: 1px solid #dce0e7;
  border-radius: 8px;
  background: #fbfcfd;
}
.exercise h2 {
  font-size: 22px;
}
.exercise > p {
  font-size: 15px;
  line-height: 1.9;
  color: #545e71;
}
.exercise details {
  border-top: 1px solid #e5e8ed;
  padding-top: 15px;
  margin-top: 15px;
  font-size: 14px;
}
.exercise summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  list-style: none;
  color: #636f88;
}
.exercise summary::-webkit-details-marker {
  display: none;
}
.exercise details[open] summary svg {
  transform: rotate(90deg);
}
.exercise details p,
.answer-text {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  margin: 17px 0 4px;
  font-size: 14px;
  line-height: 1.9;
  color: #5e6980;
}
.reference-links {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}
.reference-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: #4f6186;
  border-bottom: 1px solid transparent;
}
.reference-links a:hover {
  border-color: #919db5;
}
.lesson-pagination {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  padding-top: 30px;
  margin-top: 44px;
  border-top: 1px solid var(--border);
}
.lesson-pagination a {
  padding: 4px 0;
}
.lesson-pagination span {
  display: flex;
  align-items: center;
  gap: 7px;
  color: #828da3;
  font-size: 12px;
  margin-bottom: 9px;
}
.lesson-pagination strong {
  font-weight: 500;
  font-size: 14px;
  color: #566177;
  line-height: 1.7;
}
.lesson-pagination a.next {
  text-align: right;
}
.lesson-pagination a.next span {
  justify-content: flex-end;
}
.demo {
  border: 1px solid #dbdfe7;
  border-radius: 9px;
  background: #fcfdfe;
  overflow: hidden;
  padding: 21px 24px;
  margin: 22px 0;
}
.demo-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 18px;
}
.demo-label {
  font-size: 13px;
  font-weight: 500;
  color: #3b4a68;
}
.simulation {
  font-size: 10px;
  color: #8993a8;
}
.protocol-tabs {
  padding: 4px !important;
  background: #eef0f4 !important;
  border: 1px solid #e6e8ed !important;
  height: auto !important;
  border-radius: 6px !important;
  gap: 3px !important;
}
.protocol-tabs button {
  font-size: 12px !important;
  min-height: 30px !important;
  padding: 5px 13px !important;
  border-radius: 4px !important;
}
.protocol-tabs button[data-active] {
  color: #293d64 !important;
  box-shadow: 0 1px 3px #234e3c15 !important;
  background: #fff !important;
}
.demo-description {
  font-size: 13px;
  color: #69758e;
  line-height: 1.9;
  margin: 18px 0;
}
.connection-scene {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 22px;
  padding: 23px 15px 27px;
}
.endpoint {
  display: flex;
  align-items: center;
  flex-direction: column;
  min-width: 108px;
  gap: 5px;
  color: #78849c;
}
.endpoint > svg {
  margin-bottom: 7px;
}
.endpoint strong {
  font-size: 13px;
  font-weight: 500;
  color: #42516f;
}
.endpoint span {
  font-family: var(--font-geist-mono);
  font-size: 10px;
  color: #8f99ad;
  white-space: nowrap;
}
.connection-track {
  flex: 1;
  max-width: 280px;
  display: flex;
  align-items: center;
  flex-direction: column;
  gap: 9px;
  font-size: 11px;
  color: #7e899f;
}
.connection-track small {
  font-family: var(--font-geist-mono);
  font-size: 10px;
  color: #969fb1;
  white-space: nowrap;
}
.wire {
  height: 22px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
.wire::before {
  content: '';
  border-top: 1px dashed #bac1cf;
  position: absolute;
  width: 100%;
}
.wire svg {
  background: #fcfdfe;
  z-index: 1;
  width: 36px;
  color: #929eb6;
}
.active .wire::before {
  border-top: 1px solid #7c8ba8;
}
.active .wire svg {
  color: #334c7e;
}
.return-arrow {
  transform: rotate(180deg);
}
.demo-result {
  display: flex;
  gap: 11px;
  align-items: flex-start;
  background: #eff1f6;
  border: 1px solid #e4e7ee;
  border-radius: 5px;
  padding: 12px 14px;
  color: #66728a;
  min-height: 50px;
  margin: 12px 0;
}
.demo-result p {
  font-size: 12px;
  line-height: 1.9;
  margin: 0;
}
.step-indicator {
  font-family: var(--font-geist-mono);
  font-size: 10px;
  white-space: nowrap;
  color: #54668a;
  margin-top: 2px;
}
.packet {
  background: #f4f5f8;
  border: 1px solid #e5e8ed;
  border-radius: 5px;
  padding: 16px;
  font-size: 12px;
  line-height: 1.85;
  color: #5c687f;
  overflow: auto;
  min-height: 116px;
  margin: 14px 0;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
.demo-controls {
  display: flex;
  align-items: center;
  gap: 5px;
  margin-top: 17px;
}
.demo-controls button {
  font-size: 12px !important;
  gap: 5px !important;
  color: #4c5c7d;
  min-height: 33px;
}
.demo-controls button svg {
  width: 13px !important;
  height: 13px !important;
}
.step-dots {
  margin-left: auto;
  display: flex;
  gap: 5px;
}
.step-dots i {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #d9dde5;
}
.step-dots .on {
  background: #6a7da3;
}
.request-path {
  display: flex;
  gap: 6px;
  justify-content: space-between;
  margin: 26px 0;
}
.request-path > div {
  display: flex;
  align-items: center;
  gap: 6px;
  color: #959eb1;
}
.request-path > div > span {
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  border: 1px solid #dbdfe7;
  border-radius: 50%;
  font-size: 11px;
}
.request-path small {
  font-size: 11px;
}
.request-path .reached {
  color: var(--primary);
}
.request-path .reached > span {
  background: #e3e7f0;
  border-color: #a9b3c8;
}
.async-lanes {
  margin: 25px 0;
}
.async-lanes > div + div {
  margin-top: 23px;
}
.lane-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  margin-bottom: 12px;
  color: #5d687d;
}
.lane-label strong {
  font-weight: 500;
}
.lane-label > span {
  font-size: 11px;
  color: #919aad;
}
.timeline-row {
  display: flex;
  gap: 10px;
  align-items: center;
  margin: 7px 0;
  font-family: var(--font-geist-mono);
  font-size: 11px;
  color: #78849b;
}
.timeline-row > span {
  width: 15px;
}
.timeline {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 4px;
  flex: 1;
}
.timeline i {
  height: 28px;
  background: #f0f2f5;
  border-radius: 3px;
  font-size: 9px;
  font-style: normal;
  display: grid;
  place-items: center;
  border: 1px solid #e5e8ee;
  color: #8f99ad;
}
.timeline i.pending {
  border: 1px dashed #aab4c8;
  background: #f7f8fb;
}
.timeline i.elapsed {
  background: #a4b2cd;
  border-color: #91a0bd;
  color: #354461;
}
.time-readout {
  margin-left: auto;
  font-family: var(--font-geist-mono);
  font-size: 12px;
  color: #69758e;
  white-space: nowrap;
}
.demo-footnote {
  font-size: 11px;
  color: #8e98ab;
  margin: 19px 0 0;
  border-top: 1px solid #e7e9ee;
  padding-top: 15px;
}
@media (max-width: 1300px) {
  .material-state {
    display: none;
  }
  .topbar-actions {
    gap: 12px;
  }
  .document-grid {
    gap: 37px;
  }
}
@media (max-width: 1000px) {
  .docs-link {
    display: none;
  }
  .lesson-row p {
    display: none;
  }
  .demo {
    padding: 19px;
  }
  .simulation {
    font-size: 9px;
  }
  .phase-range {
    display: none;
  }
  .endpoint {
    min-width: 95px;
  }
  .connection-scene {
    gap: 12px;
    padding: 20px 0;
  }
  .resource-strip {
    flex-wrap: wrap;
  }
  .resource-strip > a {
    margin-left: 41px;
  }
}
@media (max-width: 767px) {
  .lesson-title {
    font-size: 28px;
    line-height: 1.6;
  }
  .lesson-nav-link {
    font-size: 14px;
  }
  .lesson-nav-group {
    font-size: 12px;
  }
  .module-link {
    font-size: 15px;
  }
  .topbar-actions button {
    font-size: 11px;
    padding: 0 5px;
  }
  .topbar-actions button svg {
    width: 14px !important;
  }
  .phase-heading {
    gap: 12px;
  }
  .phase-heading p {
    font-size: 11px;
  }
  .lesson-row {
    gap: 9px;
    padding: 16px 2px;
  }
  .lesson-row strong {
    font-size: 13px;
  }
  .lesson-duration {
    font-size: 10px;
  }
  .interactive-badge {
    font-size: 9px;
  }
  .lesson-rows {
    padding-left: 4px;
  }
  .primary-link,
  .secondary-link {
    font-size: 12px;
  }
  .overview-actions {
    gap: 9px;
  }
  .phase-marker {
    font-size: 14px;
  }
  .resource-strip {
    padding: 18px;
  }
  .next-module {
    flex-wrap: wrap;
  }
  .next-module .soon {
    margin-left: 0;
  }
  .objectives {
    padding: 18px;
  }
  .objectives li {
    font-size: 13px;
  }
  .video-pending {
    padding: 19px 15px;
  }
  .video-pending .status-label {
    display: none;
  }
  .concept p,
  .practice-step > p {
    font-size: 15px;
  }
  .exercise {
    padding: 22px 18px;
  }
  .code-block pre {
    font-size: 11px;
  }
  .line-number {
    min-width: 33px;
    padding: 0 8px 0 4px;
  }
  .lesson-pagination {
    gap: 16px;
  }
  .lesson-pagination strong {
    font-size: 13px;
  }
  .demo {
    padding: 16px;
  }
  .demo-top {
    align-items: flex-start;
    gap: 8px;
  }
  .demo-label {
    font-size: 12px;
  }
  .simulation {
    font-size: 9px;
    max-width: 120px;
    text-align: right;
  }
  .protocol-tabs {
    max-width: 100%;
  }
  .protocol-tabs button {
    font-size: 11px !important;
    padding: 4px 8px !important;
  }
  .endpoint {
    min-width: 65px;
  }
  .endpoint span {
    font-size: 8px;
  }
  .endpoint strong {
    font-size: 12px;
  }
  .connection-scene {
    gap: 9px;
  }
  .connection-track {
    font-size: 10px;
  }
  .connection-track small {
    font-size: 8px;
    white-space: normal;
    text-align: center;
  }
  .demo-result {
    padding: 10px;
  }
  .demo-result p {
    font-size: 11px;
  }
  .demo-controls {
    gap: 1px;
  }
  .demo-controls button {
    font-size: 11px !important;
    padding: 0 8px !important;
  }
  .packet {
    font-size: 11px;
    padding: 12px;
  }
  .request-path {
    gap: 3px;
    flex-wrap: wrap;
  }
  .request-path > div {
    gap: 4px;
  }
  .request-path small {
    font-size: 10px;
  }
  .request-path > div > svg {
    display: none;
  }
  .demo-footnote {
    font-size: 11px;
  }
  .page-footer {
    margin: 0 23px;
    font-size: 10px;
    flex-direction: column;
    gap: 3px;
  }
}
@media print {
  [data-slot='sidebar'],
  .topbar,
  .toc,
  .page-footer,
  .demo-controls,
  .video-section,
  .lesson-pagination,
  .overview-actions,
  .copy-button,
  .back-link {
    display: none !important;
  }
  .workspace {
    width: 100%;
  }
  .code-block pre {
    white-space: pre-wrap;
    overflow: visible;
    font-size: 10px;
  }
  .code-line {
    white-space: pre-wrap;
  }
  .code-block {
    break-inside: avoid;
  }
  .lesson-title {
    font-size: 27px;
  }
  .concept p,
  .practice-step > p {
    font-size: 12px;
  }
  .exercise details:not([open]) {
    display: none;
  }
  section {
    margin: 25px 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* SHUH.AI: original navy / blue / cool paper palette, adapted to lesson reading. */
.delivery-nodes {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin: 25px 0;
}
.delivery-nodes > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  position: relative;
  padding: 18px 6px;
  border: 1px solid #e6ebf3;
  border-radius: 6px;
  color: #98a2b3;
  background: #f8fafc;
}
.delivery-nodes > div > span {
  font-size: 12px;
}
.delivery-nodes > div > svg:last-child:not(:first-child) {
  position: absolute;
  right: -15px;
  top: 40px;
  color: #98a2b3;
}
.delivery-nodes > div.current {
  background: #edf4ff;
  border-color: #aac7ff;
  color: #2f6bff;
}
.delivery-demo .demo-result h3 {
  font-size: 14px;
  margin: 0 0 8px;
  color: #344e7d;
}
.delivery-counters {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 11px;
  color: #98a2b3;
  margin: 20px 0;
}
.delivery-counters strong {
  font-family: var(--font-geist-mono);
  font-weight: 500;
  font-size: 14px;
  color: #526990;
  margin-left: 7px;
}
@media (max-width: 767px) {
  .delivery-nodes {
    gap: 9px;
  }
  .delivery-nodes > div > span {
    font-size: 10px;
  }
  .delivery-nodes > div > svg:last-child:not(:first-child) {
    right: -12px;
    width: 11px;
  }
  .delivery-nodes > div {
    padding: 15px 2px;
  }
  .delivery-counters {
    gap: 8px;
  }
  .delivery-counters strong {
    font-size: 12px;
  }
}
:root {
  --primary: #2f6bff;
  --foreground: #111827;
  --muted-foreground: #667085;
  --accent: #edf4ff;
  --border: #e6ebf3;
  --sidebar: #071126;
  --background: #fff;
}
[data-slot='sidebar-inner'],
[data-slot='sidebar'][data-mobile='true'] {
  color: #d7e0f2;
  background: #071126;
}
.brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  padding: 22px 21px 26px;
  line-height: 1.5;
}
.brand img {
  width: 169px;
  height: auto;
  object-fit: contain;
  display: block;
}
.brand-sub {
  font-size: 11px;
  letter-spacing: 1px;
  color: #9babca;
  margin: 1px 0 0 4px;
}
.nav-caption {
  color: #8494b3;
}
.module-link {
  color: #bac6dd;
}
.module-link:hover {
  background: #111e39;
  color: #fff;
}
.module-link.selected {
  background: #19335d;
  color: #8ebaff;
}
.module-count {
  font-family: var(--font-geist-mono);
  font-size: 10px;
  color: #778baa;
}
.sidebar-note {
  color: #bdcbe3;
  border-color: #1c2b46;
}
.sidebar-note small {
  color: #798eb3;
}
.lesson-nav {
  border-color: #1c2b46;
}
.lesson-nav-group {
  color: #8497bc;
}
.lesson-nav-link {
  color: #b6c3dd;
}
.lesson-nav-link span {
  color: #6f85ad;
}
.lesson-nav-link.current,
.lesson-nav-link:hover {
  background: #11264a;
  color: #9ac2ff;
  border-left-color: #2f6bff;
}
.topbar {
  background: #071126;
  color: #fff;
  border-bottom: 1px solid #1c2b46;
}
.topbar .breadcrumbs,
.topbar .quiet-link {
  color: #aebbdd;
}
.topbar .breadcrumbs strong {
  color: #f0f4ff;
}
.topbar button {
  color: #c3cfe7;
}
.topbar button:hover {
  background: #14264a;
  color: #fff;
}
.workspace {
  background: #fff;
}
.primary-link {
  background: #2f6bff;
  border-color: #2f6bff;
}
.primary-link:hover {
  background: #2559df;
}
.brand-symbol {
  display: none;
}
.phase-heading,
.objectives {
  background: #f3f6fb;
}
.objectives {
  border-left-color: #a7c4ff;
}
.title-dot {
  color: #2f6bff;
}
.lesson-row:hover strong,
.reference-links a {
  color: #2f6bff;
}
.code-block {
  background: #f8fafc;
}
.code-toolbar {
  background: #eff3f9;
}
.code-block pre {
  color: #283954;
  font-size: 13px;
}
.syntax-keyword {
  color: #2f6bff;
}
.syntax-string {
  color: #526294;
}
.syntax-comment {
  color: #7f8da5;
}
.demo {
  background: #fbfcff;
}
.wire svg {
  background: #fbfcff;
}
.code-line {
  white-space: pre;
}
.section-heading > span {
  font-size: 12px;
}
.prerequisite-line {
  display: block;
  margin-bottom: 8px;
}
.engineering-context {
  background: #f8fafc;
  border: 1px solid #e6ebf3;
  border-radius: 8px;
  padding: 24px;
}
.context-heading {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-bottom: 15px;
  color: #2f6bff;
}
.context-heading h3 {
  margin: 0;
}
.engineering-context > p {
  font-size: 15px;
  line-height: 1.9;
  color: #667085;
}
.context-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  border-top: 1px solid #e6ebf3;
  margin-top: 20px;
  padding-top: 18px;
}
.context-columns span {
  font-size: 12px;
  color: #2f6bff;
}
.context-columns p {
  font-size: 14px;
  margin: 7px 0 0;
  color: #667085;
}
.dependencies {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 13px;
  margin-top: 22px;
}
.dependencies > span {
  color: #98a2b3;
}
.dependencies a {
  display: flex;
  gap: 5px;
  align-items: center;
  color: #2f6bff;
}
.production-panel {
  background: #f7faff;
  border: 1px solid #dce7fa;
  border-radius: 8px;
  padding: 25px;
}
.production-panel .section-heading svg {
  color: #2f6bff;
}
.production-panel h2 {
  font-size: 23px;
}
.production-scenario > span,
.failure-drill > span {
  font-size: 12px;
  color: #2f6bff;
}
.production-scenario p,
.failure-drill p {
  font-size: 15px;
  color: #52617a;
  line-height: 1.9;
  margin: 9px 0 22px;
  white-space: pre-line;
}
.decision-list {
  padding: 0 0 0 19px;
  margin: 15px 0 23px;
}
.decision-list li {
  font-size: 14px;
  line-height: 1.9;
  color: #52617a;
  margin: 8px 0;
  padding-left: 4px;
}
.failure-drill {
  border-left: 3px solid #b6cffd;
  padding: 1px 0 1px 17px;
  margin: 25px 0;
}
.failure-drill p {
  margin-bottom: 0;
}
.production-panel .check-list li {
  font-size: 14px;
}
.next-module svg {
  margin-left: auto;
  color: #2f6bff;
}
.load-error {
  min-height: 60vh;
  padding-top: 30px;
}
@media (max-width: 767px) {
  .brand img {
    width: 175px;
  }
  .context-columns {
    grid-template-columns: 1fr;
    gap: 14px;
  }
  .production-panel {
    padding: 21px 18px;
  }
  .production-panel h2 {
    font-size: 21px;
  }
  .code-block pre {
    font-size: 12px;
  }
  .phase-heading h3 {
    font-size: 15px;
  }
  .lesson-row strong {
    font-size: 14px;
  }
}