:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0b1020;
  --surface: #111a2e;
  --surface-2: #16213a;
  --border: #243352;
  --text: #e6edf7;
  --muted: #9aa8c0;
  --accent: #4ea1ff;
  --accent-2: #7c5cff;
  --ok: #3ddc97;
  --warn: #ffb020;
  --danger: #ff6b6b;
  --accent-soft: color-mix(in srgb, var(--accent) 12%, transparent);
  --accent-2-soft: color-mix(in srgb, var(--accent-2) 12%, transparent);
  --ok-soft: color-mix(in srgb, var(--ok) 12%, transparent);
  --warn-soft: color-mix(in srgb, var(--warn) 12%, transparent);
  --danger-soft: color-mix(in srgb, var(--danger) 12%, transparent);
  --surface-glass: color-mix(in srgb, var(--bg) 82%, transparent);
  --shadow: 0 24px 70px color-mix(in srgb, var(--bg) 72%, transparent);
  --glow: 0 0 42px color-mix(in srgb, var(--accent) 18%, transparent);
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f7f9fc;
  --surface: #ffffff;
  --surface-2: #eef2f8;
  --border: #d8e0ec;
  --text: #12181f;
  --muted: #5a6b7f;
  --accent: #1f6feb;
  --accent-2: #6d4dfc;
  --ok: #12875a;
  --warn: #9a6200;
  --danger: #c02b2b;
  --accent-soft: color-mix(in srgb, var(--accent) 10%, transparent);
  --accent-2-soft: color-mix(in srgb, var(--accent-2) 9%, transparent);
  --ok-soft: color-mix(in srgb, var(--ok) 10%, transparent);
  --warn-soft: color-mix(in srgb, var(--warn) 10%, transparent);
  --danger-soft: color-mix(in srgb, var(--danger) 9%, transparent);
  --surface-glass: color-mix(in srgb, var(--bg) 88%, transparent);
  --shadow: 0 24px 70px color-mix(in srgb, var(--text) 10%, transparent);
  --glow: 0 0 36px color-mix(in srgb, var(--accent) 12%, transparent);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  scroll-behavior: smooth;
  scroll-padding-top: 6rem;
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(circle at 18% -12%, var(--accent-soft), transparent 32rem),
    radial-gradient(circle at 92% 8%, var(--accent-2-soft), transparent 30rem),
    var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft JhengHei", "PingFang TC", sans-serif;
  font-size: 1rem;
  line-height: 1.85;
  text-rendering: optimizeLegibility;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 48px 48px;
  content: "";
  opacity: 0.13;
  pointer-events: none;
  mask-image: linear-gradient(to bottom, black, transparent 54%);
}

::selection {
  background: var(--accent);
  color: var(--bg);
}

:focus-visible {
  border-radius: 0.25rem;
  outline: 3px solid var(--accent);
  outline-offset: 4px;
}

a {
  color: var(--text);
  text-decoration-color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--text);
  text-decoration-color: var(--accent-2);
  text-decoration-thickness: 0.12em;
}

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

button {
  color: inherit;
  font: inherit;
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 100;
  padding: 0.7rem 1rem;
  border: 1px solid var(--accent);
  border-radius: 0.5rem;
  background: var(--surface);
  box-shadow: var(--shadow);
  transform: translateY(-180%);
}

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

.site-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  flex-direction: column;
  height: 100vh;
  padding: 1.5rem 1rem;
  overflow-y: auto;
  border-right: 1px solid var(--border);
  background:
    linear-gradient(160deg, var(--surface-2), var(--surface) 34%, var(--bg));
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  min-height: 3.25rem;
  padding: 0 0.65rem 1.25rem;
  color: var(--text);
  text-decoration: none;
}

.brand-mark {
  display: grid;
  flex: 0 0 auto;
  width: 2.5rem;
  height: 2.5rem;
  place-items: center;
  border: 1px solid var(--accent);
  border-radius: 0.8rem;
  background: var(--accent-soft);
  box-shadow: var(--glow);
}

.brand-mark svg {
  width: 1.35rem;
  height: 1.35rem;
  color: var(--accent);
}

.brand-copy {
  display: grid;
  gap: 0.05rem;
}

.brand-name {
  font-family: "Noto Sans TC", sans-serif;
  font-size: 0.98rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.35;
}

.brand-subtitle {
  color: var(--muted);
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  line-height: 1.4;
}

.section-label {
  margin: 0.8rem 0.65rem 0.5rem;
  color: var(--muted);
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.chapter-nav {
  display: grid;
  gap: 0.32rem;
}

.chapter-nav a {
  position: relative;
  display: grid;
  grid-template-columns: 1.8rem minmax(0, 1fr);
  gap: 0.65rem;
  align-items: start;
  padding: 0.66rem 0.7rem;
  border: 1px solid transparent;
  border-radius: 0.7rem;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.5;
  text-decoration: none;
  transition: color 160ms ease, background-color 160ms ease, border-color 160ms ease;
}

.chapter-nav a:hover {
  border-color: var(--border);
  background: var(--surface-2);
  color: var(--text);
}

.chapter-nav a[aria-current="page"] {
  border-color: color-mix(in srgb, var(--accent) 38%, var(--border));
  background: var(--accent-soft);
  color: var(--text);
}

.chapter-nav a[aria-current="page"]::after {
  position: absolute;
  top: 0.7rem;
  right: -1rem;
  width: 2px;
  height: calc(100% - 1.4rem);
  background: var(--accent);
  content: "";
  box-shadow: var(--glow);
}

.nav-number {
  display: inline-grid;
  width: 1.8rem;
  height: 1.8rem;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 0.45rem;
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.72rem;
  font-weight: 700;
  line-height: 1;
}

.chapter-nav a[aria-current="page"] .nav-number {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--bg);
}

.sidebar-note {
  margin: auto 0.65rem 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.76rem;
  line-height: 1.7;
}

.sidebar-note code {
  font-size: 0.76rem;
}

.main-column {
  min-width: 0;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 4.5rem;
  padding: 0.8rem clamp(1.25rem, 4vw, 3.5rem);
  border-bottom: 1px solid var(--border);
  background: var(--surface-glass);
  backdrop-filter: blur(16px);
}

.topbar-start,
.topbar-end {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.icon-button {
  display: inline-grid;
  width: 2.7rem;
  height: 2.7rem;
  padding: 0;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 0.7rem;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: border-color 160ms ease, background-color 160ms ease, transform 160ms ease;
}

.icon-button:hover {
  border-color: var(--accent);
  background: var(--surface-2);
  transform: translateY(-1px);
}

.icon-button svg {
  width: 1.2rem;
  height: 1.2rem;
}

.menu-toggle {
  display: none;
}

.progress-label {
  color: var(--muted);
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.progress-track {
  width: clamp(4rem, 10vw, 8rem);
  height: 0.25rem;
  overflow: hidden;
  border-radius: 999px;
  background: var(--border);
}

.progress-track span {
  display: block;
  width: calc(var(--progress, 0) * 1%);
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}

.content {
  width: min(100%, calc(76ch + 8rem));
  margin: 0 auto;
  padding: clamp(2.75rem, 7vw, 6.5rem) clamp(1.25rem, 5vw, 4rem) 3rem;
}

.content > * {
  max-width: 76ch;
}

.chapter-header {
  margin-bottom: clamp(3rem, 7vw, 5.5rem);
}

.chapter-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.35rem 0.65rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.chapter-badge::before {
  width: 0.42rem;
  height: 0.42rem;
  border-radius: 50%;
  background: var(--accent);
  content: "";
  box-shadow: var(--glow);
}

h1,
h2,
h3 {
  color: var(--text);
  font-family: "Noto Sans TC", "Space Grotesk", sans-serif;
  text-wrap: balance;
}

h1 {
  max-width: 19ch;
  margin: 1.25rem 0 1.15rem;
  font-size: clamp(2.25rem, 5.8vw, 4.65rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1.14;
}

h2 {
  margin: 4.5rem 0 1.2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: clamp(1.55rem, 3vw, 2.2rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.35;
}

h2::before {
  display: block;
  width: 2.25rem;
  height: 2px;
  margin-bottom: 1rem;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  content: "";
}

h3 {
  margin: 2.5rem 0 0.8rem;
  font-size: clamp(1.12rem, 2vw, 1.35rem);
  font-weight: 700;
  letter-spacing: -0.015em;
  line-height: 1.5;
}

p {
  margin: 0.9rem 0;
}

.lede {
  max-width: 62ch;
  margin: 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.22rem);
  line-height: 1.9;
}

strong {
  color: var(--text);
  font-weight: 700;
}

ul,
ol {
  margin: 1rem 0;
  padding-left: 1.55rem;
}

li {
  padding-left: 0.25rem;
}

li + li {
  margin-top: 0.5rem;
}

li::marker {
  color: var(--accent);
  font-weight: 700;
}

hr {
  height: 1px;
  margin: 3.5rem 0;
  border: 0;
  background: var(--border);
}

code {
  padding: 0.15em 0.38em;
  border: 1px solid var(--border);
  border-radius: 0.28rem;
  background: var(--surface-2);
  color: var(--text);
  font-family: "Space Grotesk", ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  font-size: 0.88em;
  overflow-wrap: anywhere;
}

blockquote,
.callout {
  position: relative;
  margin: 1.8rem 0;
  padding: 1.15rem 1.3rem 1.15rem 1.55rem;
  border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--border));
  border-radius: 0.85rem;
  background: var(--accent-soft);
  color: var(--text);
  box-shadow: 0 14px 40px color-mix(in srgb, var(--bg) 16%, transparent);
}

blockquote::before,
.callout::before {
  position: absolute;
  top: 1.2rem;
  bottom: 1.2rem;
  left: -1px;
  width: 1px;
  background: var(--accent);
  content: "";
}

blockquote p,
.callout p {
  margin: 0;
}

blockquote p + p,
.callout p + p {
  margin-top: 0.8rem;
}

.callout-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.7rem;
  color: var(--text);
  font-family: "Noto Sans TC", sans-serif;
  font-size: 0.85rem;
  font-weight: 900;
  letter-spacing: 0.04em;
}

.callout-title svg {
  width: 1rem;
  height: 1rem;
  color: var(--accent);
}

.callout--danger {
  border-color: color-mix(in srgb, var(--danger) 42%, var(--border));
  background: var(--danger-soft);
}

.callout--danger::before {
  background: var(--danger);
}

.callout--danger .callout-title {
  color: var(--danger);
}

.callout--danger .callout-title svg {
  color: var(--danger);
}

.callout--warn {
  border-color: color-mix(in srgb, var(--warn) 42%, var(--border));
  background: var(--warn-soft);
}

.callout--warn::before {
  background: var(--warn);
}

.callout--warn .callout-title {
  color: var(--warn);
}

.callout--warn .callout-title svg {
  color: var(--warn);
}

.table-scroll {
  margin: 1.65rem 0 2rem;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 0.85rem;
  background: var(--surface);
  box-shadow: var(--shadow);
  scrollbar-color: var(--accent) var(--surface-2);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  line-height: 1.65;
}

th,
td {
  min-width: 8rem;
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}

th {
  background: var(--surface-2);
  color: var(--text);
  font-family: "Noto Sans TC", sans-serif;
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.02em;
}

tbody tr:last-child td {
  border-bottom: 0;
}

tbody tr:hover {
  background: var(--accent-soft);
}

.code-shell {
  margin: 1.7rem 0 2rem;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 0.9rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.code-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 2.8rem;
  padding: 0.45rem 0.55rem 0.45rem 0.95rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
}

.code-language {
  color: var(--muted);
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.copy-button {
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 0.45rem;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.76rem;
  cursor: pointer;
}

.copy-button:hover {
  border-color: var(--accent);
  color: var(--text);
}

.copy-button[data-copied="true"] {
  border-color: var(--ok);
  color: var(--ok);
}

pre[class*="language-"],
pre {
  margin: 0;
  padding: 1.2rem 1.25rem;
  overflow-x: auto;
  background: var(--surface) !important;
  color: var(--text) !important;
  font-family: "Space Grotesk", ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  font-size: 0.84rem;
  line-height: 1.75;
  tab-size: 2;
}

pre code,
pre[class*="language-"] code {
  padding: 0;
  border: 0;
  background: transparent;
  color: inherit;
  font-size: inherit;
  text-shadow: none;
}

.token.comment,
.token.prolog,
.token.doctype,
.token.cdata {
  color: var(--muted);
}

.token.punctuation,
.token.operator {
  color: var(--text);
}

.token.property,
.token.tag,
.token.boolean,
.token.number,
.token.constant,
.token.symbol {
  color: var(--warn);
}

.token.selector,
.token.attr-name,
.token.string,
.token.char,
.token.builtin {
  color: var(--ok);
}

.token.atrule,
.token.attr-value,
.token.keyword {
  color: var(--accent);
}

.token.function,
.token.class-name {
  color: var(--accent-2);
}

.checklist {
  display: grid;
  gap: 0.65rem;
  margin: 1.35rem 0;
  padding: 0;
  list-style: none;
}

.checklist li {
  display: grid;
  grid-template-columns: 1.25rem minmax(0, 1fr);
  gap: 0.75rem;
  align-items: start;
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 0.65rem;
  background: var(--surface);
}

.checklist li::before {
  display: block;
  width: 1rem;
  height: 1rem;
  margin-top: 0.34rem;
  border: 1px solid var(--muted);
  border-radius: 0.22rem;
  content: "";
}

.diagram-card {
  margin: 2rem 0;
  padding: clamp(1rem, 3vw, 1.65rem);
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 1rem;
  background:
    radial-gradient(circle at 50% 50%, var(--accent-soft), transparent 55%),
    var(--surface);
  box-shadow: var(--shadow);
}

.diagram-caption {
  margin: 0 0 1.15rem;
  color: var(--muted);
  font-size: 0.78rem;
  text-align: center;
}

.client-map {
  display: grid;
  grid-template-columns: minmax(8rem, 1fr) minmax(4.5rem, 0.65fr) minmax(8rem, 1fr);
  gap: 0.75rem;
  align-items: center;
}

.client-node,
.vault-node {
  display: grid;
  min-height: 5rem;
  padding: 0.8rem;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 0.7rem;
  background: var(--surface-2);
  color: var(--text);
  font-family: "Noto Sans TC", sans-serif;
  font-size: 0.84rem;
  font-weight: 700;
  line-height: 1.35;
  text-align: center;
}

.client-node:nth-of-type(1) {
  grid-column: 1;
  grid-row: 1;
}

.client-node:nth-of-type(2) {
  grid-column: 1;
  grid-row: 2;
}

.client-node:nth-of-type(3) {
  grid-column: 1;
  grid-row: 3;
}

.client-node:nth-of-type(4) {
  grid-column: 1;
  grid-row: 4;
}

.vault-node {
  grid-column: 3;
  grid-row: 1 / span 4;
  min-height: 12rem;
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: var(--glow);
}

.client-lines {
  grid-column: 2;
  grid-row: 1 / span 4;
  width: 100%;
  height: 100%;
  color: var(--accent);
}

.client-lines path {
  fill: none;
  stroke: currentColor;
  stroke-dasharray: 4 6;
  stroke-width: 1.2;
}

.migration-flow {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 1.4rem;
}

.flow-node {
  position: relative;
  display: grid;
  min-height: 5.2rem;
  padding: 0.8rem;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 0.7rem;
  background: var(--surface-2);
  color: var(--text);
  font-family: "Noto Sans TC", sans-serif;
  font-size: 0.82rem;
  font-weight: 700;
  line-height: 1.4;
  text-align: center;
}

.flow-node:not(:last-child)::after {
  position: absolute;
  top: 50%;
  right: -1.05rem;
  color: var(--accent);
  content: "→";
  font-family: "Space Grotesk", sans-serif;
  font-size: 1.1rem;
  transform: translateY(-50%);
}

.page-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  width: min(100%, calc(76ch + 8rem));
  margin: 0 auto;
  padding: 0 clamp(1.25rem, 5vw, 4rem) 4rem;
}

.page-nav a {
  display: grid;
  gap: 0.2rem;
  min-height: 6.2rem;
  padding: 1rem 1.2rem;
  border: 1px solid var(--border);
  border-radius: 0.85rem;
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  transition: border-color 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

.page-nav a:hover {
  border-color: var(--accent);
  box-shadow: var(--glow);
  color: var(--text);
  transform: translateY(-2px);
}

.page-nav .next {
  grid-column: 2;
  text-align: right;
}

.nav-direction {
  color: var(--muted);
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
}

.nav-title {
  align-self: end;
  font-family: "Noto Sans TC", sans-serif;
  font-size: 0.98rem;
  font-weight: 900;
  line-height: 1.45;
}

.site-footer {
  width: min(100%, calc(76ch + 8rem));
  margin: 0 auto;
  padding: 1.2rem clamp(1.25rem, 5vw, 4rem) 2rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.75rem;
  text-align: center;
}

.drawer-overlay {
  display: none;
}

.not-found {
  display: grid;
  min-height: calc(100vh - 13rem);
  align-content: center;
  max-width: 52rem;
}

.not-found-code {
  margin: 0;
  color: var(--accent);
  font-family: "Space Grotesk", sans-serif;
  font-size: clamp(4.5rem, 15vw, 9rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 0.9;
}

.not-found h1 {
  max-width: 14ch;
}

.button-link {
  display: inline-flex;
  width: fit-content;
  margin-top: 1rem;
  padding: 0.7rem 1rem;
  border: 1px solid var(--accent);
  border-radius: 0.65rem;
  background: var(--accent-soft);
  font-weight: 700;
  text-decoration: none;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 899px) {
  .site-shell {
    display: block;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 50;
    width: min(86vw, 20rem);
    height: 100dvh;
    box-shadow: var(--shadow);
    transform: translateX(-105%);
    transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
  }

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

  .drawer-overlay {
    position: fixed;
    inset: 0;
    z-index: 40;
    display: block;
    border: 0;
    background: color-mix(in srgb, var(--bg) 72%, transparent);
    opacity: 0;
    pointer-events: none;
    transition: opacity 220ms ease;
  }

  .drawer-open .drawer-overlay {
    opacity: 1;
    pointer-events: auto;
  }

  .menu-toggle {
    display: inline-grid;
  }

  .topbar {
    min-height: 4.2rem;
    padding-inline: 1rem;
  }

  .progress-track {
    display: none;
  }

  .content {
    padding-top: 3.5rem;
  }

  .client-map {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .client-node {
    min-height: 4.2rem;
  }

  .client-node:nth-of-type(1) {
    grid-column: 1;
    grid-row: 1;
  }

  .client-node:nth-of-type(2) {
    grid-column: 2;
    grid-row: 1;
  }

  .client-node:nth-of-type(3) {
    grid-column: 1;
    grid-row: 2;
  }

  .client-node:nth-of-type(4) {
    grid-column: 2;
    grid-row: 2;
  }

  .client-lines {
    display: none;
  }

  .vault-node {
    grid-column: 1 / -1;
    grid-row: 3;
    min-height: 4.2rem;
    margin-top: 0.25rem;
  }

  .migration-flow {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .flow-node {
    min-height: 4.1rem;
  }

  .flow-node:not(:last-child)::after {
    top: auto;
    right: 50%;
    bottom: -1.35rem;
    content: "↓";
    transform: translateX(50%);
  }
}

@media (max-width: 560px) {
  body {
    font-size: 0.96rem;
  }

  h1 {
    font-size: clamp(2rem, 11vw, 3rem);
  }

  h2 {
    margin-top: 3.4rem;
  }

  .content {
    padding-inline: 1.05rem;
  }

  .page-nav {
    grid-template-columns: 1fr;
    padding-inline: 1.05rem;
  }

  .page-nav .next,
  .page-nav .prev {
    grid-column: 1;
  }

  .page-nav .next {
    text-align: left;
  }

  .progress-label {
    font-size: 0.72rem;
  }

  .topbar-end {
    gap: 0.45rem;
  }

  .icon-button {
    width: 2.5rem;
    height: 2.5rem;
  }
}