:root {
  color-scheme: light;
  --ink: #17171f;
  --muted: #5d6472;
  --line: #dde1e7;
  --panel: #ffffff;
  --soft: #f5f7fb;
  --accent: #4c2fe3;
  --accent-soft: #eef0ff;
  --ok: #0d9f73;
  --warn: #b7791f;
  --danger: #c2415d;
  --medium: #2563eb;
  --low: #64748b;
}

html[data-lang="en"] [data-lang-panel="zh"],
html[data-lang="zh"] [data-lang-panel="en"] {
  display: none !important;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--soft);
  color: var(--ink);
  font: 16px/1.55 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a {
  color: var(--accent);
}

:focus-visible {
  outline: 3px solid #0f766e;
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  z-index: 10;
  top: 12px;
  left: 12px;
  padding: 10px 14px;
  border-radius: 7px;
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  transform: translateY(-160%);
  transition: transform 0.15s ease-in-out;
}

.skip-link:focus {
  transform: translateY(0);
}

.shell {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 28px 24px;
  border-right: 1px solid var(--line);
  background: var(--panel);
}

.brand {
  margin: 0 0 24px;
  font-size: 20px;
  font-weight: 750;
}

.top-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 16px;
}

.language-toggle {
  display: inline-flex;
  flex: 0 0 auto;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.language-toggle button {
  min-width: 86px;
  border: 0;
  border-right: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  font-size: 14px;
  font-weight: 700;
  padding: 8px 12px;
}

.language-toggle button:last-child {
  border-right: 0;
}

.language-toggle button[aria-pressed="true"] {
  background: var(--accent);
  color: #fff;
}

.language-toggle button:focus-visible {
  position: relative;
  z-index: 1;
}

.nav {
  display: grid;
  gap: 8px;
}

.nav a {
  display: block;
  padding: 9px 10px;
  border-radius: 7px;
  color: var(--ink);
  text-decoration: none;
}

.nav a[aria-current="page"],
.nav a:hover {
  background: var(--accent-soft);
  color: var(--accent);
}

.nav a:focus-visible {
  color: var(--accent);
}

.content {
  width: min(1120px, calc(100vw - 320px));
  margin: 0 auto;
  padding: 38px 0 72px;
}

.content:focus {
  outline: none;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: 40px;
  line-height: 1.1;
  letter-spacing: 0;
}

h2 {
  margin: 38px 0 12px;
  font-size: 24px;
}

h3 {
  margin: 22px 0 8px;
  font-size: 18px;
}

p {
  margin: 0 0 14px;
}

.lead {
  max-width: 780px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 18px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.card,
.section {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 1px 2px rgb(15 23 42 / 8%);
}

.card {
  padding: 18px;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.video-card {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--soft);
}

.video-card h3 {
  margin-top: 0;
}

.video-card video {
  display: block;
  width: 100%;
  margin-top: 12px;
  border-radius: 6px;
  background: #111827;
}

.video-card .video-meta {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.card h2,
.card h3 {
  margin-top: 0;
}

.section {
  margin-top: 22px;
  padding: 22px;
}

.menu-guide {
  display: grid;
  gap: 16px;
  margin-top: 16px;
}

.menu-item {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcff;
}

.menu-item h3 {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 0;
}

.menu-meta {
  margin-top: 10px;
  color: var(--muted);
}

.menu-meta strong {
  color: var(--ink);
}

.shot-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.screen {
  margin: 18px 0 26px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.screen img {
  display: block;
  width: 100%;
  height: auto;
}

.screen__image {
  position: relative;
}

.screen-marker {
  position: absolute;
  top: var(--marker-y);
  left: var(--marker-x);
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border: 2px solid #fff;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 1px 4px rgb(15 23 42 / 35%);
  color: #fff;
  font-size: 15px;
  font-weight: 800;
  line-height: 1;
  pointer-events: none;
  transform: translate(-50%, -50%);
}

.caption {
  margin: 0;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

.screen-callouts {
  display: grid;
  gap: 6px;
  margin: 10px 0 0;
  padding-left: 1.35rem;
}

.screen-callouts li::marker {
  color: var(--accent);
  font-weight: 800;
}

.steps {
  display: grid;
  gap: 12px;
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.steps li {
  padding: 12px 14px;
  border-left: 4px solid var(--accent);
  background: var(--soft);
}

.checklist {
  display: grid;
  gap: 10px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.checklist li {
  padding: 11px 12px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--panel);
}

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
}

.priority {
  display: inline-block;
  min-width: 4.5rem;
  padding: 2px 8px;
  border-radius: 999px;
  color: #fff;
  font-size: 12px;
  font-weight: 750;
  text-align: center;
  text-transform: uppercase;
}

.priority.high {
  background: var(--danger);
}

.priority.medium {
  background: var(--medium);
}

.priority.low {
  background: var(--low);
}

.note {
  padding: 14px 16px;
  border-left: 4px solid var(--warn);
  background: #fff9e9;
}

.tip {
  padding: 14px 16px;
  border-left: 4px solid var(--medium);
  background: #eef5ff;
}

.alert {
  padding: 14px 16px;
  border-left: 4px solid var(--danger);
  background: #fff1f3;
}

.ok {
  border-left-color: var(--ok);
  background: #eefbf7;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 12px;
  background: var(--panel);
}

th,
td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  color: var(--muted);
  font-size: 14px;
}

.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.table-scroll table {
  min-width: 620px;
}

code {
  padding: 1px 5px;
  border-radius: 4px;
  background: var(--soft);
}

@media (max-width: 880px) {
  .shell {
    display: block;
  }

  .sidebar {
    position: static;
    height: auto;
  }

  .content {
    width: auto;
    padding: 26px 18px 56px;
  }

  .top-row {
    display: grid;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .video-grid {
    grid-template-columns: 1fr;
  }

  .shot-grid {
    grid-template-columns: 1fr;
  }

  /* Reserve room inside the framed figure for 32px annotation markers.
     Small, wide screenshots can otherwise place a correctly mapped marker
     just beyond the image edge, where the figure's clipping hides it. */
  .screen--annotated .screen__image {
    margin: 16px 0;
  }

  h1 {
    font-size: 32px;
  }
}

@media print {
  body {
    background: #fff;
  }

  .shell {
    display: block;
  }

  .sidebar {
    display: none;
  }

  .content {
    width: auto;
    padding: 0;
  }

  .section,
  .card,
  .screen {
    box-shadow: none;
    break-inside: avoid;
  }
}