:root {
  --ink: #16242b;
  --ink-soft: #526168;
  --paper: #fbfcfa;
  --surface: #ffffff;
  --line: #dfe5e2;
  --line-strong: #c7d0cc;
  --teal: #2f73d9;
  --teal-dark: #225cae;
  --teal-pale: #eaf2ff;
  --amber: #c87913;
  --amber-pale: #fff4dd;
  --red: #b43b36;
  --red-pale: #fff0ee;
  --blue: #2f68a6;
  --blue-pale: #edf5fc;
  --shadow: 0 16px 40px rgba(22, 36, 43, 0.1);
  --header-h: 56px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 22px);
}

body {
  margin: 0;
  color: var(--ink);
  background: #fafafa;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0;
  text-rendering: optimizeLegibility;
}

body.menu-open,
body.lightbox-open {
  overflow: hidden;
}

a {
  color: inherit;
}

button,
input {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

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

.reading-progress {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: 3px;
  background: transparent;
}

.reading-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--amber);
}

.site-header {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 50;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  padding: 0 max(32px, calc((100vw - 1600px) / 2 + 32px));
  border-bottom: 1px solid #eeeeee;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

.brand > strong {
  color: #1d1d1f;
  font-size: 18px;
  font-weight: 650;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.version-badge {
  padding: 3px 10px;
  border-radius: 999px;
  background: #f5f5f7;
  color: #77777c;
  font-size: 12px;
}

.theme-button {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  padding: 0;
  border: 1px solid #ececee;
  border-radius: 50%;
  background: #fafafa;
  color: #e3ae2b;
  cursor: pointer;
  font-size: 20px;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  width: min(280px, 30vw);
  height: 40px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--ink-soft);
}

.search-box:focus-within {
  border-color: var(--teal);
  box-shadow: 0 0 0 3px var(--teal-pale);
}

.search-box input {
  width: 100%;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font-size: 14px;
}

.menu-button,
.sidebar-head button {
  border: 1px solid var(--line-strong);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
}

.menu-button {
  display: none;
  min-width: 56px;
  height: 40px;
  padding: 0 13px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 700;
}

.intro-band {
  position: relative;
  overflow: hidden;
  color: white;
  background: #163c3b;
}

.intro-band::before {
  position: absolute;
  inset: 0;
  content: "";
  opacity: 0.18;
  background-image:
    linear-gradient(rgba(255,255,255,0.14) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.14) 1px, transparent 1px);
  background-size: 36px 36px;
  mask-image: linear-gradient(90deg, transparent 0, black 65%, black 100%);
}

.intro-inner {
  position: relative;
  width: min(1260px, calc(100% - 40px));
  min-height: 390px;
  margin: 0 auto;
  padding: 62px 0 42px;
}

.intro-copy {
  max-width: 700px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 10px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.14em;
}

.eyebrow {
  color: #8ed5c9;
}

.intro-copy h1 {
  max-width: 680px;
  margin: 0;
  font-family: "Songti SC", "STSong", serif;
  font-size: clamp(38px, 5.4vw, 68px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: 0;
}

.intro-lead {
  max-width: 620px;
  margin: 22px 0 26px;
  color: #d7e8e3;
  font-size: 17px;
}

.primary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 5px;
  background: #f0aa3c;
  color: #1d2a2d;
  text-decoration: none;
  font-weight: 800;
}

.route-map {
  position: absolute;
  top: 72px;
  right: 0;
  display: grid;
  gap: 3px;
  width: 320px;
}

.route-label {
  display: flex;
  align-items: center;
  gap: 13px;
  min-height: 52px;
  padding: 0 18px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.08);
  font-weight: 700;
}

.route-label span {
  color: #f4b64e;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
}

.route-map i {
  width: 1px;
  height: 14px;
  margin-left: 34px;
  background: rgba(255, 255, 255, 0.45);
}

.intro-stats {
  position: absolute;
  right: 0;
  bottom: 38px;
  display: flex;
  margin: 0;
}

.intro-stats div {
  min-width: 105px;
  padding-left: 18px;
  border-left: 1px solid rgba(255, 255, 255, 0.22);
}

.intro-stats dt {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 20px;
  font-weight: 800;
}

.intro-stats dd {
  margin: 0;
  color: #bad4ce;
  font-size: 12px;
}

.page-shell {
  display: grid;
  grid-template-columns: 280px 1080px minmax(0, 1fr);
  gap: 0;
  align-items: start;
  width: min(1600px, 100%);
  margin: var(--header-h) auto 0;
}

.sidebar {
  position: sticky;
  top: var(--header-h);
  height: calc(100vh - var(--header-h));
  max-height: none;
  padding: 32px 0;
  overflow: auto;
  border-right: 1px solid #ececee;
  background: #ffffff;
}

.sidebar-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px 16px;
  color: var(--ink-soft);
  font-size: 12px;
  font-weight: 800;
}

.sidebar-head button {
  display: none;
  width: 34px;
  height: 34px;
  border-radius: 5px;
  font-size: 24px;
  line-height: 1;
}

.sidebar nav {
  display: grid;
  gap: 10px;
}

.sidebar nav a {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 43px;
  padding: 5px 12px;
  border-left: 2px solid transparent;
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 13px;
  font-weight: 650;
}

.sidebar nav .nav-section {
  min-height: 48px;
  margin: 0 20px;
  padding: 10px 16px;
  border: 0;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 650;
}

.sidebar nav .nav-section strong {
  font-weight: 800;
}

.nav-group {
  display: grid;
}

.nav-children {
  display: grid;
  margin: 2px 20px 4px 48px;
  padding-left: 13px;
  border-left: 1px solid #e5e5e7;
}

.sidebar nav .nav-children a {
  position: relative;
  min-height: 36px;
  padding: 6px 10px;
  border-left: 0;
  color: #718087;
  font-size: 12px;
  font-weight: 600;
}

.sidebar nav .nav-children.numbered a {
  gap: 9px;
}

.sidebar nav .nav-children a::before {
  position: absolute;
  top: 50%;
  left: -17px;
  width: 7px;
  height: 1px;
  content: "";
  background: var(--line-strong);
}

.sidebar nav a span {
  color: #89969b;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 10px;
}

.sidebar nav a:hover,
.sidebar nav a.is-active {
  border-left-color: transparent;
  background: linear-gradient(135deg, #2867c7, #3d86ef);
  color: #ffffff;
}

.sidebar nav .nav-children a:hover,
.sidebar nav .nav-children a.is-active {
  border-left-color: transparent;
  background: transparent;
  color: var(--teal-dark);
}

.sidebar nav .nav-children a.is-active::before {
  height: 2px;
  background: var(--teal);
}

.nav-group.is-active > .nav-section {
  border-left-color: transparent;
  background: linear-gradient(135deg, #2867c7, #3d86ef);
  color: #ffffff;
  box-shadow: 0 5px 14px rgba(47, 115, 217, 0.2);
}

.nav-group.is-active > .nav-section span {
  color: #ffffff;
}

.sidebar nav a.is-active span {
  color: var(--teal);
}

.sidebar nav .nav-section.is-active span {
  color: #ffffff;
}

.sidebar-note {
  margin: 22px 20px 0;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--ink-soft);
  font-size: 12px;
}

.sidebar-note strong {
  color: var(--ink);
}

.sidebar-note p {
  margin: 5px 0 0;
}

.sidebar-scrim {
  display: none;
}

.tutorial {
  min-width: 0;
  width: 1080px;
  min-height: calc(100vh - var(--header-h));
  padding: 64px 80px 100px;
  background: #ffffff;
}

.guide-section {
  padding: 0 0 100px;
  border-bottom: 0;
}

.guide-section[hidden] {
  display: none;
}

.guide-category {
  display: block;
  padding: 0 0 32px;
  border-bottom: 0;
}

.guide-category > span {
  display: none;
}

.guide-category h2 {
  margin: 0;
  font-family: inherit;
  font-size: 36px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 0;
}

.guide-category p:last-child {
  margin: 10px 0 0;
  color: var(--ink-soft);
}

.guide-category + .guide-section {
  padding-top: 0;
}

.section-heading {
  display: block;
  margin-bottom: 32px;
}

.section-index {
  display: none;
}

.section-kicker {
  display: none;
}

.section-heading h2 {
  margin: 0;
  font-family: inherit;
  font-size: 36px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 0;
}

.section-heading > div:last-child > p:last-child {
  max-width: 680px;
  margin: 12px 0 0;
  color: var(--ink-soft);
  font-size: 16px;
}

.fast-step {
  padding: 40px 0 80px;
  border-top: 1px solid #eeeeee;
}

.fast-step .section-heading {
  margin-bottom: 20px;
}

.fast-step .section-heading h2 {
  font-size: 26px;
  font-weight: 650;
  line-height: 1.3;
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: start;
}

.prose-block {
  padding: 4px 0;
}

.prose-block.compact {
  max-width: 720px;
}

.prose-block h3,
.option-list h3,
.target-block h3 {
  margin: 0;
  font-size: 18px;
  line-height: 1.4;
}

.prose-block > p {
  margin: 10px 0 0;
  color: var(--ink-soft);
}

.note {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 14px;
  margin: 20px 0;
  padding: 16px 18px;
  border-left: 3px solid;
  border-radius: 0 5px 5px 0;
  font-size: 14px;
}

.note strong {
  font-size: 12px;
  letter-spacing: 0.06em;
}

.note p {
  margin: 0;
}

.note.info {
  border-color: var(--blue);
  background: var(--blue-pale);
}

.note.warning {
  border-color: var(--amber);
  background: var(--amber-pale);
}

.note.danger {
  border-color: var(--red);
  background: var(--red-pale);
}

.shot {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--surface);
  box-shadow: 0 10px 26px rgba(22, 36, 43, 0.07);
  cursor: zoom-in;
}

.shot::after {
  position: absolute;
  top: 12px;
  right: 12px;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 5px;
  content: "+";
  color: white;
  background: rgba(22, 36, 43, 0.76);
  font-size: 21px;
  line-height: 1;
  opacity: 0;
  transition: opacity 160ms ease;
}

.shot:hover::after,
.shot:focus-within::after {
  opacity: 1;
}

.shot img {
  width: 100%;
  height: auto;
  aspect-ratio: auto;
  object-fit: contain;
  background: #f3f5f4;
}

.shot.portrait img {
  aspect-ratio: auto;
}

.shot img:not([src]) {
  color: transparent;
}

.shot figcaption {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  color: var(--ink-soft);
  font-size: 12px;
}

.shot figcaption span {
  flex: 0 0 auto;
  color: var(--teal);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-weight: 800;
}

.shot-grid {
  display: grid;
  gap: 24px;
  margin-top: 26px;
}

.shot-grid .wide {
  grid-column: auto;
}

.mode-switch {
  display: inline-flex;
  gap: 4px;
  margin: 0 0 24px 86px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #f0f3f1;
}

.mode-switch button {
  min-height: 38px;
  padding: 0 16px;
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  font-weight: 700;
}

.mode-switch button.is-active {
  background: var(--surface);
  color: var(--teal-dark);
  box-shadow: 0 2px 8px rgba(22, 36, 43, 0.08);
}

.tab-panel {
  margin-left: 86px;
}

.video-tutorial {
  margin-top: 22px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #111719;
  box-shadow: var(--shadow);
}

.video-tutorial video {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #111719;
}

.video-tutorial video[hidden] {
  display: none;
}

.video-launch {
  display: grid;
  place-items: center;
  align-content: center;
  gap: 14px;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
  background: #111719;
  color: #ffffff;
  cursor: pointer;
}

.video-launch[hidden] {
  display: none;
}

.video-launch > span {
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  padding-left: 4px;
  border: 1px solid rgba(255, 255, 255, 0.45);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  font-size: 24px;
}

.video-launch strong {
  font-size: 15px;
}

.video-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 62px;
  padding: 10px 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  color: white;
}

.video-meta > div {
  display: flex;
  align-items: center;
  gap: 12px;
}

.video-meta span {
  color: #f0aa3c;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 10px;
  font-weight: 800;
}

.video-meta strong {
  font-size: 14px;
}

.video-meta a {
  color: #a9d8cf;
  font-size: 12px;
  font-weight: 700;
  text-decoration: none;
}

.video-meta a:hover {
  color: white;
}

.step-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.step-list li {
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 10px;
  min-height: 126px;
  padding: 19px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.step-list li > span,
.target-head > span {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--teal-pale);
  color: var(--teal);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 11px;
  font-weight: 800;
}

.step-list p {
  margin: 5px 0 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.step-list.horizontal {
  grid-template-columns: 1fr;
  margin-bottom: 30px;
}

.step-list.horizontal li {
  min-height: 150px;
}

.option-list {
  display: grid;
  gap: 0;
  margin: 0 0 28px;
  border-top: 1px solid var(--line);
}

.option-list.two-col {
  grid-template-columns: 1fr;
  border-left: 1px solid var(--line);
}

.option-list article {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 15px;
  padding: 20px 16px;
  border-bottom: 1px solid var(--line);
}

.option-list.two-col article {
  border-right: 1px solid var(--line);
}

.option-list article > span {
  color: var(--amber);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-weight: 800;
}

.option-list p {
  margin: 5px 0 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.definition-list {
  display: grid;
  grid-template-columns: 1fr;
  margin: 24px 0 28px;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.definition-list div {
  padding: 20px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.definition-list dt {
  margin-bottom: 7px;
  font-weight: 800;
}

.definition-list dd {
  margin: 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.tip-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin: 24px 0;
}

.tip-row p {
  margin: 0;
  padding: 16px 18px;
  border-left: 3px solid var(--teal);
  background: var(--teal-pale);
  color: var(--ink-soft);
  font-size: 14px;
}

.tip-row strong {
  display: block;
  color: var(--ink);
}

.priority-line {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 58px;
  margin-bottom: 26px;
  padding: 10px 16px;
  overflow-x: auto;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
  font-size: 13px;
}

.priority-line > span {
  margin-right: auto;
  color: var(--ink-soft);
}

.priority-line i {
  color: var(--amber);
  font-style: normal;
}

.key-values {
  margin: 18px 0 0;
}

.key-values div {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 14px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
}

.key-values dt {
  font-size: 13px;
  font-weight: 800;
}

.key-values dd {
  margin: 0;
  color: var(--ink-soft);
  font-size: 13px;
}

.target-block {
  margin: 32px 0;
  padding-top: 28px;
  border-top: 1px solid var(--line-strong);
}

.target-head {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 14px;
  align-items: start;
  margin-bottom: 20px;
}

.target-head p {
  margin: 5px 0 0;
  color: var(--ink-soft);
}

.formula {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 4px 18px;
  margin: 28px 0;
  padding: 22px;
  border: 1px solid #acd0c8;
  background: var(--teal-pale);
}

.formula span {
  grid-row: 1 / 3;
  display: grid;
  place-items: center;
  width: 58px;
  height: 58px;
  background: var(--teal);
  color: white;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-weight: 800;
}

.formula p {
  margin: 4px 0 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.completion-line {
  display: grid;
  grid-template-columns: 1fr 40px 1fr;
  align-items: center;
  margin: 6px 0 30px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.completion-line > div {
  padding: 24px;
}

.completion-line span {
  color: var(--amber);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
  font-weight: 800;
}

.completion-line strong {
  display: block;
  margin-top: 6px;
}

.completion-line p {
  margin: 6px 0 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.completion-line > i {
  color: var(--teal);
  font-style: normal;
  text-align: center;
}

.completion-line.single {
  grid-template-columns: 1fr;
}

.substep-heading {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 14px;
  align-items: start;
  margin: 72px 0 24px;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.substep-heading > span {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--teal-pale);
  color: var(--teal);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 11px;
  font-weight: 800;
}

.substep-heading h2 {
  margin: 0;
  font-size: 26px;
  line-height: 1.3;
}

.substep-heading p {
  margin: 6px 0 0;
  color: var(--ink-soft);
}

.faq-section details {
  border-top: 1px solid var(--line-strong);
}

.faq-section details:last-of-type {
  border-bottom: 1px solid var(--line-strong);
}

.faq-section summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px 4px;
  cursor: pointer;
  list-style: none;
}

.faq-section summary::-webkit-details-marker {
  display: none;
}

.faq-section summary::after {
  margin-left: auto;
  content: "+";
  color: var(--teal);
  font-size: 23px;
}

.faq-section details[open] summary::after {
  content: "−";
}

.faq-section summary span {
  color: var(--amber);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 11px;
}

.faq-body {
  padding: 0 0 28px 38px;
}

.faq-body > p,
.faq-body > ol {
  max-width: 760px;
  color: var(--ink-soft);
}

.faq-body .shot {
  margin-top: 22px;
}

.external-link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  margin-top: 6px;
  padding: 0 14px;
  border: 1px solid var(--teal);
  border-radius: 5px;
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 800;
  text-decoration: none;
}

.external-link:hover {
  background: var(--teal-pale);
}

body.theme-dark {
  --ink: #f1f3f5;
  --ink-soft: #aeb7bf;
  --paper: #15191d;
  --surface: #1d2227;
  --line: #343b42;
  --line-strong: #46505a;
  background: #15191d;
  color: var(--ink);
}

body.theme-dark .site-header,
body.theme-dark .sidebar,
body.theme-dark .tutorial {
  background: #1b2025;
  border-color: #30373e;
}

body.theme-dark .brand > strong {
  color: #ffffff;
}

body.theme-dark .version-badge,
body.theme-dark .theme-button {
  border-color: #343b42;
  background: #252b31;
  color: #f2c55c;
}

body.theme-dark .shot,
body.theme-dark .step-list li,
body.theme-dark .definition-list div {
  background: #20262b;
  border-color: #343b42;
}

body.theme-dark .shot img {
  background: #171b1f;
}

body.theme-dark .note.info,
body.theme-dark .note.warning,
body.theme-dark .note.danger,
body.theme-dark .tip-row p,
body.theme-dark .formula {
  color: #dce2e7;
  background: #252b31;
}

.search-empty {
  margin-top: 80px;
  padding: 32px;
  border: 1px solid var(--line);
  text-align: center;
}

.search-empty p {
  margin: 6px 0 0;
  color: var(--ink-soft);
}

.page-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 34px 0 12px;
}

.page-footer p {
  margin: 3px 0 0;
  color: var(--ink-soft);
  font-size: 12px;
}

.page-footer a {
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 800;
  text-decoration: none;
}

.lightbox {
  width: min(96vw, 1500px);
  max-width: none;
  height: min(92vh, 980px);
  max-height: none;
  padding: 0;
  overflow: hidden;
  border: 0;
  border-radius: 7px;
  background: #101719;
  color: white;
  box-shadow: 0 30px 90px rgba(0, 0, 0, 0.42);
}

.lightbox::backdrop {
  background: rgba(8, 13, 15, 0.82);
  backdrop-filter: blur(5px);
}

.lightbox-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 60px;
  padding: 0 12px 0 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.lightbox-bar p {
  margin: 0;
  overflow: hidden;
  color: #d4dddd;
  font-size: 13px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lightbox-bar button,
.lightbox-stage button {
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 5px;
  background: rgba(255, 255, 255, 0.08);
  color: white;
  cursor: pointer;
}

.lightbox-bar button {
  width: 38px;
  height: 38px;
  font-size: 25px;
}

.lightbox-stage {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) 52px;
  gap: 12px;
  align-items: center;
  height: calc(100% - 60px);
  padding: 14px;
}

.lightbox-stage img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.lightbox-stage button {
  width: 48px;
  height: 48px;
  font-size: 36px;
  line-height: 1;
}

@media (max-width: 1400px) {
  .page-shell {
    grid-template-columns: 260px minmax(0, 1fr);
  }

  .tutorial {
    width: auto;
    padding: 64px;
  }
}

@media (max-width: 1080px) {
  .route-map,
  .intro-stats {
    display: none;
  }

  .page-shell {
    grid-template-columns: 230px minmax(0, 1fr);
    gap: 0;
  }
}

@media (max-width: 820px) {
  :root {
    --header-h: 62px;
  }

  .site-header {
    padding: 0 16px;
  }

  .brand-copy small {
    display: none;
  }

  .search-box {
    width: min(210px, 42vw);
  }

  .menu-button {
    display: block;
  }

  .intro-inner {
    min-height: 360px;
    padding-top: 52px;
  }

  .intro-copy h1 {
    font-size: 44px;
  }

  .page-shell {
    display: block;
    width: 100%;
  }

  .tutorial {
    width: auto;
    padding: 48px 32px 80px;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 90;
    width: min(310px, 86vw);
    max-height: none;
    padding: 18px 12px;
    background: var(--paper);
    box-shadow: var(--shadow);
    transform: translateX(-105%);
    transition: transform 200ms ease;
  }

  .sidebar.is-open {
    transform: translateX(0);
  }

  .sidebar-head button {
    display: block;
  }

  .sidebar-scrim {
    position: fixed;
    inset: 0;
    z-index: 80;
    display: block;
    background: rgba(8, 18, 20, 0.44);
    opacity: 0;
    pointer-events: none;
    transition: opacity 200ms ease;
  }

  .sidebar-scrim.is-open {
    opacity: 1;
    pointer-events: auto;
  }

  .guide-section {
    padding-bottom: 76px;
  }

  .section-heading {
    grid-template-columns: 44px 1fr;
    gap: 12px;
  }

  .guide-category {
    padding-top: 0;
  }

  .definition-list,
  .option-list.two-col {
    grid-template-columns: 1fr;
  }

  .shot-grid .wide {
    grid-column: auto;
  }

  .mode-switch,
  .tab-panel,
  .option-list {
    margin-left: 56px;
  }

  .definition-list div {
    min-height: auto;
  }

  .step-list.horizontal {
    grid-template-columns: 1fr;
  }

  .step-list.horizontal li {
    min-height: 110px;
  }
}

@media (max-width: 560px) {
  body {
    font-size: 15px;
  }

  .brand-mark {
    width: 38px;
    height: 38px;
  }

  .version-badge {
    display: none;
  }

  .brand-copy {
    display: none;
  }

  .header-actions {
    flex: 1;
    justify-content: flex-end;
  }

  .search-box {
    width: min(100%, 220px);
  }

  .intro-inner {
    width: calc(100% - 32px);
    min-height: 410px;
    padding: 48px 0 38px;
  }

  .intro-copy h1 {
    font-size: 38px;
  }

  .intro-lead {
    font-size: 15px;
    line-height: 1.7;
  }

  .tutorial {
    padding: 40px 16px 70px;
  }

  .section-heading {
    display: block;
    margin-bottom: 25px;
  }

  .guide-category {
    display: block;
  }

  .guide-category > span {
    display: none;
  }

  .section-index {
    padding: 0 0 8px;
  }

  .section-heading h2 {
    font-size: 30px;
  }

  .fast-step .section-heading h2 {
    font-size: 24px;
  }

  .mode-switch,
  .tab-panel,
  .option-list {
    margin-left: 0;
  }

  .mode-switch {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    width: 100%;
  }

  .video-meta {
    align-items: flex-start;
    flex-direction: column;
    gap: 4px;
    padding: 12px 14px;
  }

  .step-list,
  .step-list.horizontal,
  .tip-row {
    grid-template-columns: 1fr;
  }

  .step-list li {
    min-height: 0;
  }

  .note {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .shot-grid {
    gap: 18px;
  }

  .shot img,
  .shot.portrait img {
    aspect-ratio: auto;
    min-height: 160px;
  }

  .priority-line > span {
    display: none;
  }

  .plan-copy {
    display: block;
  }

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

  .formula span {
    grid-row: auto;
  }

  .completion-line {
    grid-template-columns: 1fr;
  }

  .completion-line > i {
    transform: rotate(90deg);
  }

  .faq-body {
    padding-left: 0;
  }

  .page-footer {
    align-items: flex-start;
    gap: 18px;
  }

  .lightbox {
    width: 100vw;
    height: 100vh;
    border-radius: 0;
  }

  .lightbox-stage {
    grid-template-columns: 38px minmax(0, 1fr) 38px;
    gap: 4px;
    padding: 8px;
  }

  .lightbox-stage button {
    width: 36px;
    height: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}

@media print {
  .site-header,
  .sidebar,
  .sidebar-scrim,
  .reading-progress,
  .primary-link,
  .shot::after {
    display: none !important;
  }

  .intro-band {
    color: var(--ink);
    background: white;
  }

  .intro-inner {
    min-height: auto;
    padding: 30px 0;
  }

  .intro-lead,
  .eyebrow {
    color: var(--ink-soft);
  }

  .page-shell {
    display: block;
    width: 100%;
  }

  .guide-section {
    break-inside: avoid;
  }

  .shot {
    box-shadow: none;
  }
}