:root {
  color-scheme: dark;
  --bg: #111318;
  --panel: #171a20;
  --panel-strong: #1f242c;
  --text: #f6f8fb;
  --muted: #b8c2d0;
  --soft: #8f9aaa;
  --line: #343943;
  --blue: #5367d8;
  --blue-strong: #4355c9;
  --cyan: #20d7dc;
  --green: #15b981;
  --amber: #f5a524;
  --shadow: rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 92px;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.58;
  letter-spacing: 0;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

code,
pre {
  font-family:
    "Cascadia Code", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

code {
  padding: 0.12rem 0.34rem;
  border: 1px solid rgba(83, 103, 216, 0.28);
  border-radius: 6px;
  background: rgba(83, 103, 216, 0.14);
  color: #dce2ff;
  font-size: 0.92em;
}

pre {
  overflow-x: auto;
  margin: 16px 0 0;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #0d0f14;
}

pre code {
  padding: 0;
  border: 0;
  background: transparent;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  min-height: 72px;
  padding: 0 32px;
  background: rgba(17, 19, 24, 0.9);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.05rem;
}

.brand img {
  width: 40px;
  height: 40px;
  object-fit: contain;
}

.side-menu a {
  border-radius: 8px;
  color: var(--muted);
  font-weight: 750;
}

.side-menu a:hover,
.side-menu a:focus-visible {
  color: var(--text);
  background: var(--panel-strong);
  outline: none;
}

.eyebrow,
.section-label,
.chapter-kicker {
  margin: 0 0 12px;
  color: var(--cyan);
  font-size: 0.82rem;
  font-weight: 850;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  letter-spacing: 0;
}

h1 {
  margin: 0;
  font-size: 4rem;
  line-height: 1;
}

h2 {
  margin: 0;
  font-size: 2rem;
  line-height: 1.15;
}

h3 {
  margin: 34px 0 0;
  font-size: 1.16rem;
  line-height: 1.28;
}

p {
  margin: 0;
}

.intro,
.manual-layout {
  width: min(1320px, calc(100% - 40px));
  margin: 0 auto;
}

.intro {
  display: grid;
  grid-template-columns: minmax(260px, 0.9fr) minmax(300px, 1.1fr);
  gap: 40px;
  padding: 54px 0 34px;
  color: var(--muted);
}

.intro h2 {
  color: var(--text);
}

.manual-layout {
  display: grid;
  grid-template-columns: 270px minmax(0, 1fr);
  gap: 34px;
  align-items: start;
  padding: 18px 0 72px;
}

.side-menu {
  position: sticky;
  top: 92px;
  max-height: calc(100vh - 112px);
  overflow-y: auto;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(23, 26, 32, 0.92);
  box-shadow: 0 18px 42px var(--shadow);
}

.side-menu-title {
  margin-bottom: 8px;
  color: var(--soft);
  font-size: 0.78rem;
  font-weight: 850;
  text-transform: uppercase;
}

.side-menu a {
  display: block;
  padding: 8px 10px;
  font-size: 0.92rem;
}

.side-menu a + a {
  margin-top: 3px;
}

.manual-content {
  min-width: 0;
}

.manual-chapter {
  padding: 34px 0 44px;
  border-top: 1px solid var(--line);
}

.manual-chapter:first-child {
  padding-top: 0;
  border-top: 0;
}

.manual-chapter > p,
.manual-chapter > ul,
.manual-chapter > ol,
.manual-chapter > .callout,
.manual-chapter > pre {
  max-width: 860px;
}

.manual-chapter p {
  margin-top: 16px;
  color: var(--muted);
}

.manual-chapter h2 + p,
.manual-chapter h3 + p {
  margin-top: 14px;
}

.manual-chapter ul,
.manual-chapter ol {
  margin: 16px 0 0;
  padding-left: 23px;
  color: var(--muted);
}

.manual-chapter li + li {
  margin-top: 7px;
}

.chapter-kicker {
  color: var(--amber);
}

.callout {
  margin-top: 20px;
  padding: 16px 18px;
  border: 1px solid rgba(245, 165, 36, 0.45);
  border-radius: 8px;
  background: rgba(245, 165, 36, 0.11);
  color: #f3d7a2;
}

.manual-figure,
.shot {
  overflow: hidden;
  margin: 26px 0 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 16px 36px var(--shadow);
}

.manual-figure {
  max-width: 980px;
}

.manual-figure.narrow {
  max-width: 430px;
}

.manual-figure img,
.shot img {
  width: 100%;
  height: auto;
  background: #0f1116;
  border-bottom: 1px solid var(--line);
}

.manual-figure figcaption,
.shot figcaption {
  margin: 0;
  padding: 13px 15px 15px;
  color: var(--muted);
  font-size: 0.93rem;
}

.schema-grid {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.schema-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

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

.schema-card p {
  max-width: none;
}

.schema-card ul {
  max-width: none;
}

.final-checklist {
  columns: 2;
  column-gap: 34px;
}

.final-checklist li {
  break-inside: avoid;
}

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

.shot {
  margin-top: 0;
}

.shot img {
  aspect-ratio: 16 / 9;
  object-fit: cover;
  object-position: top left;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 24px 32px;
  color: var(--soft);
  border-top: 1px solid var(--line);
  background: #0d0f14;
  font-size: 0.92rem;
}

@media (max-width: 1100px) {
  .site-header {
    padding: 16px 20px;
  }

  .manual-layout {
    grid-template-columns: 1fr;
  }

  .side-menu {
    top: 126px;
    z-index: 12;
    max-height: none;
    overflow-x: auto;
    overflow-y: hidden;
    white-space: nowrap;
  }

  .side-menu-title {
    display: inline-block;
    margin: 0 10px 0 0;
  }

  .side-menu a {
    display: inline-flex;
    margin-top: 0;
  }

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

  h1 {
    font-size: 3rem;
  }

  h2 {
    font-size: 1.65rem;
  }
}

@media (max-width: 720px) {
  html {
    scroll-padding-top: 150px;
  }

  h1 {
    font-size: 2.45rem;
  }

  .intro,
  .manual-layout {
    width: min(100% - 28px, 1320px);
  }

  .side-menu {
    top: 136px;
    padding: 12px;
  }

  .manual-chapter {
    padding: 30px 0 38px;
  }

  .schema-card {
    padding: 16px;
  }

  .final-checklist {
    columns: 1;
  }

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

  footer {
    align-items: flex-start;
    flex-direction: column;
  }
}