:root {
  color-scheme: light dark;
  --ink: light-dark(#172b46, #e3ecfa);
  --muted: light-dark(#5b6d85, #adbed5);
  --blue: light-dark(#285cda, #97b6ff);
  --border: light-dark(#dce4f0, #39485d);
  --surface: light-dark(#ffffff, #172131);
  --page: light-dark(#f5f7fb, #101724);
  --tint: light-dark(#eaf0fd, #243553);
  --button-ink: light-dark(#ffffff, #172131);
  --brandbar: light-dark(#ffffff, #e8edf5);
  --brandbar-muted: light-dark(#5b6d85, #4c6080);
}

* {
  box-sizing: border-box;
}
[hidden] {
  display: none !important;
}
body {
  display: flex;
  flex-direction: column;
  min-height: 100svh;
  margin: 0;
  background: var(--surface);
  color: var(--ink);
  font: 14px/1.65 "Microsoft YaHei UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
a {
  color: inherit;
  text-decoration: none;
}
button {
  font: inherit;
  cursor: pointer;
}
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 4px;
}
h1, h2, h3, p {
  margin: 0;
}
.page-width {
  width: calc(100% - 64px);
  margin-inline: auto;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--brandbar);
  color: #233954;
  isolation: isolate;
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: 78px;
  padding-block: 16px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 18px;
  white-space: nowrap;
}
.company-logo {
  display: block;
  flex-shrink: 0;
  width: max-content;
  color: #246b9d;
}
.logo-wordmark {
  display: block;
  font-family: "Arial Black", Arial, sans-serif;
  font-size: 23px;
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: .7px;
}
.logo-wordmark sup {
  margin-left: 2px;
  font-family: Arial, sans-serif;
  font-size: 9px;
  line-height: 1;
  vertical-align: top;
  letter-spacing: 0;
}
.logo-tagline {
  display: block;
  margin-top: 3px;
  font-size: 10px;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: .2px;
}
.brand-title {
  color: var(--brandbar-muted);
  font-size: 13px;
}
.header-nav {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-left: auto;
}
.header-link {
  padding-block: 5px;
  color: var(--brandbar-muted);
  font-size: 13px;
  white-space: nowrap;
}
.header-link:hover, .header-link[aria-current="page"] {
  color: #285cda;
}
.header-link[aria-current="page"] {
  font-weight: 600;
}

.home-main {
  display: flex;
  flex: 1;
  flex-direction: column;
}
.welcome {
  display: grid;
  flex: 1;
  grid-template-columns: 210px minmax(0, 1fr) 210px;
  align-content: center;
  align-items: center;
  gap: 48px;
  padding: 72px 0;
}
.welcome h1 {
  grid-column: 2;
  font-size: clamp(40px, 7vw, 96px);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -2px;
  text-align: center;
}
.device-summary {
  border-left: 2px solid var(--blue);
  padding-left: 24px;
}
.device-summary > div {
  padding-block: 9px;
}
.device-summary strong {
  display: block;
  font-size: 16px;
  font-weight: 600;
}
.device-summary span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}
.tutorial-entry {
  display: flex;
  align-items: center;
  gap: 22px;
  padding: 27px 30px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--tint);
  transition: border-color 150ms, transform 150ms;
}
.tutorial-entry:hover {
  border-color: var(--blue);
  transform: translateY(-2px);
}
.entry-icon {
  display: grid;
  place-items: center;
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  border-radius: 10px;
  background: var(--surface);
  color: var(--blue);
}
.entry-icon svg {
  width: 26px;
  height: 26px;
}
.entry-copy {
  flex: 1;
  min-width: 0;
}
.entry-copy strong {
  display: block;
  font-size: 22px;
  font-weight: 650;
  text-wrap: balance;
}
.entry-copy > span {
  display: block;
  margin-top: 5px;
  color: var(--muted);
  font-size: 13px;
}
.entry-action {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
  color: var(--blue);
  font-weight: 600;
  white-space: nowrap;
}
.entry-action > span {
  font-size: 22px;
  font-weight: 400;
}
.quick-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 32px;
  padding: 35px 0 26px;
}
.quick-link {
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}
.quick-link h2 {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 14px;
  font-weight: 600;
}
.quick-link p {
  margin-top: 8px;
  color: var(--muted);
  font-size: 12px;
}
.quick-link svg {
  width: 18px;
  height: 18px;
  color: var(--muted);
}
.quick-link:hover h2 {
  color: var(--blue);
}
.entry-icon svg, .quick-link svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.site-footer {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 12px;
  padding-block: 20px;
  color: var(--muted);
  font-size: 11px;
}

.workspace {
  display: grid;
  flex: 1;
  grid-template-columns: 250px minmax(0, 1fr);
  width: 100%;
  min-height: calc(100svh - 78px);
}
.directory-sidebar {
  padding: 27px 18px 40px;
  border-right: 1px solid var(--border);
  background: var(--page);
}
.directory-toggle {
  display: none;
}
.directory-section {
  margin-bottom: 4px;
}
.directory-group {
  margin: 4px 0 9px 12px;
}
.directory-group summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  list-style: none;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
.directory-group summary::-webkit-details-marker {
  display: none;
}
.directory-group summary::before {
  content: "";
  width: 6px;
  height: 6px;
  border-right: 1px solid var(--muted);
  border-bottom: 1px solid var(--muted);
  transform: rotate(-45deg);
}
.directory-group[open] summary::before {
  transform: rotate(45deg);
}
.directory-link {
  display: block;
  padding: 8px 12px 8px 35px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 12px;
}
.directory-link:hover, .directory-link[aria-current="page"] {
  color: var(--blue);
  background: var(--tint);
}
.directory-link[aria-current="page"] {
  font-weight: 600;
}
.directory-section-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--ink);
  font-size: 13px;
  font-weight: 600;
  list-style: none;
  cursor: pointer;
}
.directory-section-title:hover {
  color: var(--blue);
  background: var(--tint);
}
.directory-section > summary::-webkit-details-marker {
  display: none;
}
.directory-section > summary::after {
  content: "";
  width: 6px;
  height: 6px;
  border-right: 1px solid var(--muted);
  border-bottom: 1px solid var(--muted);
  transform: rotate(-45deg);
}
.directory-section[open] > summary::after {
  transform: rotate(45deg);
}
.content-main {
  min-width: 0;
  padding: 32px clamp(24px, 4vw, 54px) 48px;
}
.breadcrumbs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
  color: var(--muted);
  font-size: 12px;
}
.breadcrumbs a:hover {
  color: var(--blue);
}
.watch-heading {
  margin-bottom: 25px;
}
.category {
  display: inline-block;
  padding: 3px 9px;
  border-radius: 4px;
  color: var(--blue);
  background: var(--tint);
  font-size: 12px;
}
.watch-heading h1 {
  margin-top: 9px;
  font-size: clamp(25px, 2.8vw, 32px);
  line-height: 1.5;
  font-weight: 650;
  letter-spacing: -.5px;
}
.watch-heading p {
  margin-top: 9px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.85;
}
.player-frame {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #0d1422;
}
.player-frame video {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  max-height: 68vh;
  object-fit: contain;
}
.player-hint {
  margin-top: 12px;
  color: var(--muted);
  font-size: 12px;
}
.adjacent-tutorials {
  display: flex;
  justify-content: space-between;
  gap: 22px;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}
.adjacent-tutorials a {
  max-width: 48%;
  font-size: 12px;
}
.adjacent-tutorials a:hover strong {
  color: var(--blue);
}
.adjacent-tutorials span {
  display: block;
  margin-bottom: 4px;
  color: var(--muted);
  font-size: 11px;
}
.adjacent-tutorials strong {
  font-weight: 500;
}
#next-tutorial {
  margin-left: auto;
  text-align: right;
}
.resource-list {
  margin-top: 28px;
}
.resource-link {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  padding-block: 23px;
  border-top: 1px solid var(--border);
}
.resource-kind {
  min-width: 42px;
  padding: 5px 6px;
  border-radius: 4px;
  background: var(--tint);
  color: var(--blue);
  font-size: 11px;
  text-align: center;
}
.resource-link > div {
  flex: 1;
  min-width: 0;
}
.resource-link h2 {
  font-size: 15px;
  font-weight: 600;
  overflow-wrap: anywhere;
}
.resource-link p {
  margin-top: 6px;
  color: var(--muted);
  font-size: 12px;
}
.resource-action {
  flex-shrink: 0;
  margin-left: auto;
  padding-top: 4px;
  color: var(--blue);
  font-size: 12px;
}
.resource-link:hover h2 {
  color: var(--blue);
}
.empty-state {
  padding-block: 32px;
}
.empty-state h1 {
  font-size: 27px;
}
.empty-state p {
  margin: 12px 0 24px;
  color: var(--muted);
}
.primary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  padding: 11px 20px;
  border-radius: 8px;
  background: var(--blue);
  color: var(--button-ink);
  font-size: 14px;
  font-weight: 600;
}
.primary-link:hover {
  filter: brightness(.94);
}
.eyebrow {
  margin-bottom: 10px;
  color: var(--blue);
  font-size: 12px;
}

@media (max-width: 1080px) {
  .welcome {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 56px 0 40px;
  }
  .welcome h1 {
    grid-column: auto;
  }
  .device-summary {
    display: flex;
    justify-content: center;
    gap: 48px;
    padding: 0;
    border: 0;
  }
  .workspace {
    grid-template-columns: 220px minmax(0, 1fr);
  }
}
@media (max-width: 760px) {
  .page-width {
    width: calc(100% - 44px);
  }
  .welcome {
    gap: 28px;
    padding: 48px 0 36px;
  }
  .device-summary {
    gap: 32px;
  }
  .device-summary strong {
    font-size: 14px;
  }
  .quick-links {
    gap: 22px;
  }
  .workspace {
    grid-template-columns: 194px minmax(0, 1fr);
  }
  .directory-sidebar {
    padding: 23px 10px;
  }
  .content-main {
    padding: 28px 24px 40px;
  }
  .resource-link {
    flex-wrap: wrap;
  }
  .resource-action {
    margin-left: 60px;
  }
}
@media (max-width: 680px) {
  .workspace {
    display: block;
    min-height: 0;
  }
  .directory-sidebar {
    padding: 12px 22px;
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }
  .directory-toggle {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 14px;
    width: 100%;
    padding: 7px 0;
    border: 0;
    color: var(--ink);
    background: transparent;
    font-size: 13px;
    text-align: left;
  }
  .directory-menu {
    display: none;
    padding-top: 16px;
  }
  .directory-sidebar.is-open .directory-menu {
    display: block;
  }
  .directory-link {
    padding-block: 11px;
  }
  .directory-group summary, .directory-section > summary {
    padding-block: 10px;
  }
  .content-main {
    padding: 25px 22px 38px;
  }
}
@media (max-width: 540px) {
  .page-width {
    width: calc(100% - 40px);
  }
  .header-inner {
    flex-wrap: wrap;
    gap: 9px;
    padding-block: 15px 12px;
  }
  .brand {
    gap: 12px;
  }
  .logo-wordmark {
    font-size: 22px;
    letter-spacing: .65px;
  }
  .logo-tagline {
    font-size: 9px;
    letter-spacing: .1px;
  }
  .brand-title {
    font-size: 12px;
  }
  .header-nav {
    justify-content: flex-end;
    gap: 22px;
    width: 100%;
    margin-left: 0;
  }
  .header-link {
    font-size: 12px;
  }
  .welcome {
    gap: 25px;
    padding: 42px 0 28px;
  }
  .welcome h1 {
    letter-spacing: -1px;
  }
  .device-summary {
    justify-content: space-between;
    gap: 12px;
  }
  .device-summary strong {
    font-size: 13px;
  }
  .device-summary span {
    font-size: 11px;
  }
  .tutorial-entry {
    flex-wrap: wrap;
    gap: 13px;
    padding: 22px 18px;
  }
  .entry-icon {
    width: 42px;
    height: 42px;
  }
  .entry-icon svg {
    width: 23px;
    height: 23px;
  }
  .entry-copy strong {
    font-size: 19px;
  }
  .entry-copy {
    flex-basis: calc(100% - 55px);
  }
  .entry-copy > span {
    max-width: 175px;
    font-size: 12px;
  }
  .entry-action {
    margin-left: 55px;
    font-size: 12px;
  }
  .quick-links {
    grid-template-columns: 1fr;
    gap: 18px;
    padding: 28px 0 14px;
  }
  .quick-link {
    padding-bottom: 16px;
  }
  .quick-link p {
    margin-left: 27px;
  }
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    gap: 5px;
  }
  .breadcrumbs {
    gap: 8px;
    font-size: 11px;
  }
  .watch-heading h1 {
    font-size: 25px;
  }
  .resource-link {
    gap: 12px;
  }
  .resource-action {
    margin-left: 54px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .tutorial-entry {
    transition: none;
  }
}