:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-alt: #f5f5f7;
  --card: #ffffff;
  --panel: #f5f5f7;
  --text: #1d1d1f;
  --text-2: #6e6e73;
  --text-3: #86868b;
  --line: #d2d2d7;
  --hairline: rgba(0, 0, 0, 0.1);
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --accent-soft: rgba(0, 113, 227, 0.1);
  --link: #0066cc;
  --on-accent: #ffffff;
  --danger: #d70015;
  --danger-text: #d70015;
  --success: #248a3d;
  --focus: #0071e3;
  --nav-bg: rgba(255, 255, 255, 0.8);
  --field: #ffffff;
  --device-body: #e3e3e8;
  --device-foot: #c7c7cc;
  --device-bezel: #1d1d1f;
  --device-glass: #0b0b0c;
  --device-edge: rgba(0, 0, 0, 0.16);
  --device-shadow: rgba(0, 0, 0, 0.16);
  --device-shadow-clear: rgba(0, 0, 0, 0);
  --cable: #b8b8bf;
  --screen-a: #1e63e9;
  --screen-b: #5eaeff;
  --glow: rgba(0, 113, 227, 0.09);
  --glow-clear: rgba(0, 113, 227, 0);
  --glass: rgba(246, 246, 246, 0.74);
  --glass-line: rgba(0, 0, 0, 0.12);
  --shadow-float: 0 18px 50px rgba(0, 0, 0, 0.14), 0 2px 8px rgba(0, 0, 0, 0.06);
  --ease-standard: cubic-bezier(0.25, 0.1, 0.25, 1);
  --ease-settle: cubic-bezier(0.2, 0.8, 0.2, 1);
  --dur-press: 150ms;
  --dur-toggle: 250ms;
  --dur-state: 350ms;
  --dur-enter: 600ms;
  --gutter: 22px;
  --page: 980px;
  --narrow: 692px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-alt: #161617;
    --card: #1d1d1f;
    --panel: #1d1d1f;
    --text: #f5f5f7;
    --text-2: #a1a1a6;
    --text-3: #86868b;
    --line: #424245;
    --hairline: rgba(255, 255, 255, 0.12);
    --accent-soft: rgba(41, 151, 255, 0.16);
    --link: #2997ff;
    --danger-text: #ff6961;
    --success: #30d158;
    --focus: #2997ff;
    --nav-bg: rgba(22, 22, 23, 0.8);
    --field: #000000;
    --device-edge: rgba(0, 0, 0, 0.4);
    --device-shadow: rgba(0, 0, 0, 0);
    --cable: #636366;
    --glow: rgba(41, 151, 255, 0.17);
    --glow-clear: rgba(41, 151, 255, 0);
    --glass: rgba(40, 40, 42, 0.74);
    --glass-line: rgba(255, 255, 255, 0.14);
    --shadow-float: 0 18px 50px rgba(0, 0, 0, 0.6), 0 2px 8px rgba(0, 0, 0, 0.4);
  }
}

/* Base */

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

[hidden] {
  display: none !important;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: 52px;
  background: var(--bg);
}

:is(h1, h2, h3, p, li)[id],
sup a[id] {
  scroll-margin-top: 20px;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.47;
  letter-spacing: -0.022em;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-synthesis: none;
}

main {
  flex: 1 0 auto;
}

img,
svg {
  max-width: 100%;
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

strong {
  font-weight: 600;
  color: var(--text);
}

p {
  margin: 0;
  text-wrap: pretty;
}

h1,
h2,
h3 {
  margin: 0;
  font-weight: 700;
  color: var(--text);
  text-wrap: balance;
}

h1,
.headline {
  font-family: var(--font-display);
}

sup {
  font-size: 0.55em;
  line-height: 0;
  vertical-align: 0.9em;
  letter-spacing: 0;
}

sup a {
  color: inherit;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 8px;
  z-index: 100;
  padding: 8px 14px;
  border-radius: 10px;
  background: var(--bg);
  color: var(--text);
}

.skip-link:focus {
  left: var(--gutter);
}

.wrap {
  width: min(var(--page), 100% - 2 * var(--gutter));
  margin-inline: auto;
}

.wrap.narrow {
  width: min(var(--narrow), 100% - 2 * var(--gutter));
}

/* Navigation */

.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--nav-bg);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--hairline);
  view-transition-name: site-nav;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 52px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
}

.brand:hover {
  text-decoration: none;
}

.brand img {
  display: block;
  width: 26px;
  height: 26px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  font-size: 14px;
  letter-spacing: -0.016em;
}

.nav-links a:not(.button) {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--text-2);
  transition: color var(--dur-press) var(--ease-standard);
}

.nav-links a:not(.button):hover,
.nav-links a[aria-current="page"],
.nav-links a.in-section {
  color: var(--text);
  text-decoration: none;
}

.read-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: 0 50%;
  opacity: 0;
  pointer-events: none;
}

/* Buttons */

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 22px;
  border: 0;
  border-radius: 980px;
  background: var(--accent);
  color: var(--on-accent);
  font: inherit;
  font-size: 17px;
  letter-spacing: -0.022em;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  transition: background-color var(--dur-press) var(--ease-standard), color var(--dur-press) var(--ease-standard), box-shadow var(--dur-press) var(--ease-standard), transform var(--dur-press) var(--ease-standard);
}

.button:hover {
  background: var(--accent-hover);
  text-decoration: none;
}

.button:active {
  transform: scale(0.98);
}

.button.small {
  min-height: 30px;
  padding: 0 14px;
  font-size: 14px;
  letter-spacing: -0.016em;
}

.button.large {
  min-height: 52px;
  padding: 0 30px;
  font-size: 18px;
}

.button.secondary {
  background: transparent;
  color: var(--link);
  box-shadow: inset 0 0 0 1px var(--link);
}

.button.secondary:hover {
  background: var(--link);
  color: var(--on-accent);
}

.button.danger {
  background: var(--danger);
}

.button.danger:hover {
  background: var(--danger);
  filter: brightness(1.08);
}

.button:disabled {
  cursor: default;
  opacity: 0.45;
}

.button:disabled:active {
  transform: none;
}

.button[aria-busy="true"],
.text-button[aria-busy="true"] {
  opacity: 0.75;
}

.button[aria-busy="true"]::before,
.text-button[aria-busy="true"]::before {
  content: "";
  width: 16px;
  height: 16px;
  flex: none;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.text-button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0;
  border: 0;
  background: none;
  color: var(--link);
  font: inherit;
  letter-spacing: inherit;
  cursor: pointer;
}

.text-button:hover {
  text-decoration: underline;
}

.text-button:disabled {
  color: var(--text-3);
  cursor: default;
  text-decoration: none;
}

.more::after {
  content: "\00a0\203a";
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Sections */

.section {
  padding-block: 112px;
}

.section.alt {
  background: var(--bg-alt);
}

.eyebrow {
  font-size: 21px;
  line-height: 1.19;
  font-weight: 600;
  letter-spacing: 0.011em;
  color: var(--text-2);
  margin-bottom: 10px;
}

.headline {
  font-size: clamp(34px, 5.4vw, 56px);
  line-height: 1.07;
  letter-spacing: -0.005em;
  max-width: 15em;
}

.section-lead {
  margin-top: 24px;
  max-width: 34em;
  font-size: clamp(19px, 2.1vw, 21px);
  line-height: 1.42;
  letter-spacing: 0.011em;
  color: var(--text-2);
}

.fine {
  font-size: 14px;
  line-height: 1.43;
  letter-spacing: -0.016em;
  color: var(--text-2);
}

.fine a {
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

/* Search field, shared by the help pages, support, the home page and the 404 page */

.search {
  position: relative;
}

.search-field {
  position: relative;
  display: flex;
  align-items: center;
}

.search-field svg {
  position: absolute;
  left: 16px;
  width: 18px;
  height: 18px;
  fill: none;
  stroke: var(--text-2);
  stroke-width: 1.8;
  stroke-linecap: round;
  pointer-events: none;
}

.search-input {
  width: 100%;
  height: 50px;
  padding: 0 18px 0 46px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--field);
  color: var(--text);
  font: inherit;
  font-size: 17px;
  letter-spacing: -0.022em;
  -webkit-appearance: none;
  appearance: none;
  transition: border-color var(--dur-press) var(--ease-standard), box-shadow var(--dur-press) var(--ease-standard);
}

.search-input::placeholder {
  color: var(--text-2);
  opacity: 1;
}

.search-input::-webkit-search-decoration {
  -webkit-appearance: none;
}

.search-input:focus {
  outline: none;
  border-color: var(--focus);
  box-shadow: 0 0 0 1px var(--focus);
}

/* The ⌘K hint, where there is a keyboard; site.js adds it. */
.search-key {
  position: absolute;
  right: 12px;
  display: none;
  padding: 1px 7px;
  border: 1px solid var(--line);
  border-radius: 6px;
  font: 500 12px/1.5 var(--font);
  letter-spacing: 0.02em;
  color: var(--text-2);
  pointer-events: none;
  transition: opacity var(--dur-press) var(--ease-standard);
}

@media (hover: hover) and (pointer: fine) {
  .search-key {
    display: block;
  }

  .search-field:has(.search-key) .search-input {
    padding-right: 68px;
  }
}

.search-input:focus ~ .search-key,
.search-input:not(:placeholder-shown) ~ .search-key {
  opacity: 0;
}

.search-panel {
  position: absolute;
  z-index: 30;
  top: calc(100% + 8px);
  left: 0;
  right: 0;
  max-height: min(70vh, 460px);
  overflow: auto;
  padding: 6px;
  border: 1px solid var(--glass-line);
  border-radius: 14px;
  background: var(--glass);
  -webkit-backdrop-filter: saturate(180%) blur(24px);
  backdrop-filter: saturate(180%) blur(24px);
  box-shadow: var(--shadow-float);
  text-align: left;
}

.search-panel[hidden] {
  display: none;
}

.search-results {
  margin: 0;
  padding: 0;
  list-style: none;
}

.search-results a {
  display: block;
  padding: 10px 12px;
  border-radius: 9px;
  color: var(--text);
  text-decoration: none;
}

.search-results a:hover,
.search-results a.is-active {
  background: var(--accent-soft);
  text-decoration: none;
}

.search-results a.is-active {
  box-shadow: inset 0 0 0 2px var(--focus);
}

.search-results .result-title {
  display: block;
  font-weight: 600;
  line-height: 1.3;
}

.search-results .result-path {
  display: block;
  margin-top: 2px;
  font-size: 13px;
  letter-spacing: -0.01em;
  color: var(--text-2);
}

.search-panel .result-all {
  display: block;
  margin-top: 2px;
  padding: 10px 12px;
  border-top: 1px solid var(--hairline);
  font-size: 15px;
}

.search-empty {
  padding: 10px 12px 6px;
  font-size: 15px;
  color: var(--text-2);
}

.search-panel .search-contact {
  margin-top: 2px;
  padding: 10px 12px 8px;
  border-top: 1px solid var(--hairline);
  font-size: 14px;
  color: var(--text-2);
}

/* The search palette of ⌘K: a modal dialog where the reader is. */
.palette {
  width: min(640px, 100% - 2 * var(--gutter));
  max-width: none;
  max-height: min(600px, 100% - 14vh - 24px);
  margin: 12vh auto auto;
  padding: 0;
  overflow: hidden;
  border: 1px solid var(--glass-line);
  border-radius: 16px;
  background: var(--glass);
  -webkit-backdrop-filter: saturate(180%) blur(30px);
  backdrop-filter: saturate(180%) blur(30px);
  color: var(--text);
  box-shadow: var(--shadow-float);
}

.palette[open] {
  display: flex;
  flex-direction: column;
}

.palette::backdrop {
  background: rgba(0, 0, 0, 0.3);
}

.palette-search {
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  min-height: 0;
}

.palette .search-field {
  border-bottom: 1px solid var(--hairline);
}

.palette .search-input {
  height: 58px;
  padding-left: 50px;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  font-size: 19px;
}

.palette .search-field svg {
  left: 18px;
  width: 20px;
  height: 20px;
}

.palette .search-panel {
  position: static;
  flex: 1 1 auto;
  max-height: none;
  min-height: 0;
  border: 0;
  border-radius: 0;
  background: none;
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
  box-shadow: none;
}

.palette-keys {
  padding: 9px 16px 10px;
  border-top: 1px solid var(--hairline);
  font-size: 12px;
  color: var(--text-2);
}

@media (hover: none), (pointer: coarse) {
  .palette-keys {
    display: none;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .palette[open] {
    animation: palette-in 0.2s var(--ease-settle);
  }

  .palette[open]::backdrop {
    animation: palette-fade 0.2s var(--ease-standard);
  }
}

@keyframes palette-in {
  from {
    opacity: 0;
    transform: translateY(-6px) scale(0.985);
  }
}

@keyframes palette-fade {
  from {
    opacity: 0;
  }
}

/* Footer */

.footer {
  flex: none;
  padding-block: 22px 34px;
  background: var(--bg-alt);
  color: var(--text-2);
  font-size: 12px;
  line-height: 1.33;
  letter-spacing: -0.01em;
}

.footer-inner {
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: 0 0 14px;
  padding: 0;
  list-style: none;
}

.footer-links a {
  display: inline-block;
  padding-block: 4px;
}

.footer-group {
  padding-block: 4px;
  font-weight: 600;
  color: var(--text);
}

.footer a {
  color: var(--text-2);
}

.footer a:hover,
.footer a[aria-current="page"] {
  color: var(--text);
}

.footer p + p {
  margin-top: 8px;
}

/* The analytics choice (decision D91), built by analytics.js: one line at the bottom of the window */

.consent {
  position: fixed;
  z-index: 40;
  inset-inline: var(--gutter);
  bottom: max(var(--gutter), env(safe-area-inset-bottom));
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 20px;
  max-width: 720px;
  margin-inline: auto;
  padding: 14px 14px 14px 22px;
  border: 1px solid var(--hairline);
  border-radius: 18px;
  background: var(--card);
  box-shadow: var(--shadow-float);
  font-size: 15px;
  line-height: 1.4;
  letter-spacing: -0.016em;
}

.consent-text,
.consent-current {
  color: var(--text-2);
}

.consent-current {
  font-size: 13px;
}

.consent-text a {
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

.consent-actions {
  display: flex;
  gap: 10px;
}

.consent-actions .button {
  min-height: 36px;
  padding-inline: 18px;
  font-size: 15px;
  letter-spacing: -0.016em;
}

@media (prefers-reduced-motion: no-preference) {
  .consent {
    animation: consent-in var(--dur-enter) var(--ease-settle);
  }
}

@keyframes consent-in {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
}

@media print {
  .consent {
    display: none;
  }
}

/* Page transitions where the browser supports them; the header stays still. */

@media (prefers-reduced-motion: no-preference) {
  @view-transition {
    navigation: auto;
  }

  ::view-transition-old(root),
  ::view-transition-new(root) {
    animation-duration: 220ms;
    animation-timing-function: var(--ease-standard);
  }
}

/* Small screens */

@media (max-width: 734px) {
  :root {
    --gutter: 20px;
  }

  .section {
    padding-block: 72px;
  }

  .nav-links {
    gap: 18px;
  }

  .nav-links a.optional {
    display: none;
  }
}

@media (max-width: 374px) {
  :root {
    --gutter: 16px;
  }

  .nav-links {
    gap: 14px;
  }
}

@media (max-width: 339px) {
  .brand-name {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
  }
}

@media (prefers-contrast: more) {
  :root {
    --line: var(--text-2);
    --hairline: var(--text-2);
    --text-3: var(--text-2);
  }
}

@media (forced-colors: active) {
  .button {
    border: 1px solid ButtonText;
  }

  .read-progress {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
    scroll-behavior: auto !important;
  }

  .button[aria-busy="true"]::before,
  .text-button[aria-busy="true"]::before,
  .spinner {
    animation-duration: 2.4s;
  }
}