:root {
  --color-bg: #F7FAFF;
  --color-panel: #FFFFFF;
  --color-panel-soft: #EAF4FF;
  --color-border: #D8E7F7;
  --color-accent: #1493FF;
  --color-accent-dark: #064A9F;
  --color-text: #081B46;
  --color-text-muted: #536786;
  --color-success: #FFB43C;
  --color-warn: #D98A00;
  --color-error: #A85D00;
  --color-hero-deep: #06143A;
  --color-hero-mid: #082E72;
  --color-hero-blue: #0B5FC0;
  --color-white-soft: #F8FBFF;
  --color-white-muted: #C6D8F3;
  --color-white-faint: #90ABD2;
  --color-line-dark: #214B80;
  --color-card-ink: #102A55;
  --color-shadow-deep: rgba(1, 12, 42, 0.34);
  --color-shadow-card: rgba(1, 20, 58, 0.28);
  --color-shadow-soft: rgba(20, 147, 255, 0.18);
  --color-white-overlay: rgba(255, 255, 255, 0.08);
  --color-white-overlay-strong: rgba(255, 255, 255, 0.14);
  --color-white-border: rgba(255, 255, 255, 0.18);
  --color-grid: rgba(112, 180, 255, 0.08);
  --color-amber-glow: rgba(255, 180, 60, 0.32);
  --color-focus: rgba(255, 180, 60, 0.44);
  --color-veil: rgba(1, 12, 42, 0.62);
  --color-accent-glow: rgba(20, 147, 255, 0.26);
  --color-disabled: #A9B8CD;
  --font-display: Inter, "Noto Sans SC", "Noto Sans JP", "Noto Sans KR", system-ui, sans-serif;
  --font-body: Inter, "Noto Sans SC", "Noto Sans JP", "Noto Sans KR", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Consolas, monospace;
  --radius-logo: 13px;
  --radius-pill: 999px;
  --radius-button: 12px;
  --radius-card: 28px;
  --radius-card-inner: 18px;
  --radius-small: 8px;
  --shadow-navigation: 0 12px 38px var(--color-shadow-deep);
  --shadow-device: 0 34px 70px var(--color-shadow-card), 0 8px 24px var(--color-shadow-soft);
  --shadow-device-edge: 0 12px 0 var(--color-shadow-deep);
  --shadow-button: 0 12px 28px var(--color-amber-glow);
  --shadow-panel: 0 18px 45px var(--color-shadow-soft);
  --gradient-hero: linear-gradient(145deg, var(--color-hero-deep) 0%, var(--color-text) 32%, var(--color-accent-dark) 74%, var(--color-hero-blue) 100%);
  --gradient-title: linear-gradient(90deg, var(--color-panel) 0%, var(--color-panel-soft) 42%, var(--color-accent) 100%);
  --gradient-logo: linear-gradient(145deg, var(--color-accent) 0%, var(--color-accent-dark) 100%);
  --gradient-switch: linear-gradient(135deg, var(--color-success) 0%, var(--color-warn) 100%);
  --gradient-soft: linear-gradient(145deg, var(--color-panel) 0%, var(--color-panel-soft) 100%);
  --wrap-max: 1180px;
  --gutter: clamp(16px, 4vw, 40px);
  --header-height: 76px;
  --toc-offset: 92px;
  --transition-fast: 160ms ease;
  --transition-reveal: 560ms cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
  background: var(--color-bg);
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 0;
  margin: 0;
  overflow-x: clip;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

main,
section,
article,
aside,
header,
footer,
nav,
div {
  min-width: 0;
}

img,
svg,
video,
canvas {
  display: block;
  max-width: 100%;
}

img {
  height: auto;
}

button,
input,
select,
textarea {
  color: inherit;
  font: inherit;
}

button,
summary {
  cursor: pointer;
}

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

p,
ul,
ol,
blockquote,
pre,
table {
  margin-top: 0;
}

p {
  margin-bottom: 1.1em;
}

ul,
ol {
  padding-left: 1.35em;
}

code,
kbd,
samp {
  font-family: var(--font-mono);
}

:not(pre) > code {
  max-width: 100%;
  padding: 0.12em 0.4em;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  background: var(--color-panel-soft);
  overflow-wrap: anywhere;
}

pre {
  max-width: 100%;
  padding: 20px;
  overflow-x: auto;
  border: 1px solid var(--color-line-dark);
  border-radius: var(--radius-card-inner);
  background: var(--color-hero-deep);
  color: var(--color-white-soft);
  font-family: var(--font-mono);
  line-height: 1.65;
  -webkit-overflow-scrolling: touch;
}

pre code {
  white-space: pre;
  overflow-wrap: normal;
}

table {
  border-collapse: collapse;
}

h1,
h2,
h3,
h4 {
  margin-top: 0;
  color: var(--color-text);
  font-family: var(--font-display);
  text-wrap: balance;
}

h1,
.hero-title {
  font-size: clamp(52px, 5.3vw, 72px);
  font-weight: 850;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(32px, 3.5vw, 48px);
  font-weight: 820;
  line-height: 1.16;
  letter-spacing: -0.018em;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(21px, 2vw, 28px);
  font-weight: 780;
  line-height: 1.3;
}

h4 {
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 760;
}

.title-keep {
  white-space: nowrap;
}

.text-muted {
  color: var(--color-text-muted);
}

.mono {
  font-family: var(--font-mono);
}

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

.wrap-wide {
  --wrap-max: 1388px;
}

.reading-wrap {
  width: min(100%, calc(48rem + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  overflow-x: clip;
  padding-top: clamp(72px, 9vw, 128px);
  padding-bottom: clamp(72px, 9vw, 128px);
}

.section-soft {
  background: var(--color-panel-soft);
}

.section-dark {
  background: var(--gradient-hero);
  color: var(--color-white-soft);
}

.section-dark h2,
.section-dark h3 {
  color: var(--color-panel);
}

.section-heading {
  max-width: 790px;
  margin-bottom: 42px;
}

.section-heading.centered {
  margin-inline: auto;
  text-align: center;
}

.eyebrow,
.badge,
.tag {
  display: inline-flex;
  max-width: 100%;
  min-height: 28px;
  align-items: center;
  gap: 8px;
  padding: 4px 11px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel-soft);
  color: var(--color-accent-dark);
  font-size: 12px;
  font-weight: 720;
  line-height: 1.4;
}

.eyebrow-dot,
.status-dot,
.icon-dot {
  width: 8px;
  height: 8px;
  flex: 0 0 8px;
  border-radius: var(--radius-pill);
  background: var(--color-success);
  box-shadow: 0 0 0 5px var(--color-amber-glow);
}

.tag-accent {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: var(--color-panel);
}

.panel,
.card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  background: var(--color-panel);
  box-shadow: var(--shadow-panel);
}

.panel-soft {
  background: var(--gradient-soft);
}

.button {
  display: inline-flex;
  min-width: 132px;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 0 22px;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-button);
  background: var(--color-accent);
  color: var(--color-panel);
  font-weight: 760;
  line-height: 1.2;
  text-align: center;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
  box-shadow: var(--shadow-panel);
}

.button-primary {
  border-color: var(--color-success);
  background: var(--color-success);
  color: var(--color-text);
  box-shadow: var(--shadow-button);
}

.button-secondary {
  border-color: var(--color-border);
  background: var(--color-panel);
  color: var(--color-text);
}

.button-ghost {
  border-color: var(--color-border);
  background: var(--color-panel-soft);
  color: var(--color-accent-dark);
}

.button[aria-disabled="true"],
.button:disabled {
  border-color: var(--color-disabled);
  background: var(--color-disabled);
  box-shadow: none;
  cursor: not-allowed;
  transform: none;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

#site-header,
.site-header {
  position: relative;
  z-index: 50;
  min-height: var(--header-height);
  border-bottom: 1px solid var(--color-white-border);
  background: var(--color-hero-deep);
  color: var(--color-panel);
  box-shadow: var(--shadow-navigation);
}

.header-shell {
  position: relative;
  z-index: 3;
  display: flex;
  width: min(100%, calc(1388px + var(--gutter) * 2));
  min-height: var(--header-height);
  align-items: center;
  gap: 24px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 11px;
}

.site-brand img {
  width: 42px;
  height: 42px;
  flex: 0 0 42px;
  border-radius: var(--radius-logo);
  box-shadow: 0 9px 24px var(--color-shadow-soft);
}

.brand-copy {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  white-space: nowrap;
}

.brand-main {
  font-size: 20px;
  font-weight: 850;
  letter-spacing: -0.02em;
}

.brand-local {
  color: var(--color-white-muted);
  font-size: 13px;
  font-weight: 550;
}

.desktop-nav {
  display: flex;
  flex: 1 1 auto;
  align-items: center;
  justify-content: flex-end;
  gap: 21px;
  white-space: nowrap;
}

.desktop-nav a {
  position: relative;
  padding: 27px 0 25px;
  color: var(--color-white-muted);
  font-size: 13px;
  font-weight: 580;
}

.desktop-nav a::after {
  position: absolute;
  right: 0;
  bottom: 17px;
  left: 0;
  height: 2px;
  content: "";
  border-radius: var(--radius-pill);
  background: var(--color-success);
  opacity: 0;
  transform: scaleX(0.4);
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.desktop-nav a:hover,
.desktop-nav a:focus-visible,
.desktop-nav a[aria-current="page"] {
  color: var(--color-panel);
}

.desktop-nav a:hover::after,
.desktop-nav a:focus-visible::after,
.desktop-nav a[aria-current="page"]::after {
  opacity: 1;
  transform: scaleX(1);
}

.header-tools {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 8px;
}

.header-login {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1px solid var(--color-white-border);
  border-radius: var(--radius-button);
  background: var(--color-panel);
  color: var(--color-text);
  font-size: 13px;
  font-weight: 780;
}

.language-menu {
  position: relative;
}

.language-toggle,
.menu-toggle {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-white-border);
  border-radius: var(--radius-button);
  background: var(--color-white-overlay);
  color: var(--color-white-muted);
}

.language-toggle {
  gap: 7px;
  padding: 0 10px;
  font-size: 12px;
}

.language-list {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 70;
  display: none;
  width: 168px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card-inner);
  background: var(--color-panel);
  box-shadow: var(--shadow-navigation);
}

.language-menu.is-open .language-list {
  display: grid;
}

.language-list a {
  display: flex;
  min-height: 42px;
  align-items: center;
  padding: 8px 11px;
  border-radius: var(--radius-small);
  color: var(--color-text);
  font-size: 13px;
}

.language-list a:hover,
.language-list a:focus-visible,
.language-list a[aria-current="true"] {
  background: var(--color-panel-soft);
  color: var(--color-accent-dark);
}

.menu-toggle {
  display: none;
  min-width: 44px;
  padding: 0;
}

.menu-toggle-lines {
  position: relative;
  width: 19px;
  height: 14px;
}

.menu-toggle-lines::before,
.menu-toggle-lines::after,
.menu-toggle-lines span {
  position: absolute;
  left: 0;
  width: 19px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  content: "";
}

.menu-toggle-lines::before {
  top: 0;
}

.menu-toggle-lines span {
  top: 6px;
}

.menu-toggle-lines::after {
  top: 12px;
}

.mobile-nav {
  position: absolute;
  top: var(--header-height);
  right: 0;
  left: 0;
  z-index: 5;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  overscroll-behavior: contain;
  border-top: 1px solid var(--color-border);
  background: var(--color-panel);
  box-shadow: var(--shadow-navigation);
  color: var(--color-text);
  -webkit-overflow-scrolling: touch;
}

.mobile-nav.is-open {
  display: block;
}

.mobile-nav-group {
  padding: 10px var(--gutter) 18px;
}

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 48px;
  align-items: center;
  padding: 10px 12px;
  border-bottom: 1px solid var(--color-border);
  font-weight: 680;
}

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

.mobile-language-title {
  margin: 15px 12px 4px;
  color: var(--color-text-muted);
  font-size: 12px;
  font-weight: 760;
}

.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 2;
  display: none;
  border: 0;
  background: var(--color-veil);
}

.nav-veil.is-open {
  display: block;
}

.site-footer {
  position: relative;
  overflow-x: clip;
  padding-top: 72px;
  background: var(--color-hero-deep);
  color: var(--color-white-muted);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(240px, 1.25fr) repeat(3, minmax(150px, 1fr));
  gap: 48px;
  padding-bottom: 54px;
}

.footer-brand {
  max-width: 340px;
}

.footer-brand .site-brand {
  color: var(--color-panel);
}

.footer-brand p {
  margin-top: 18px;
  font-size: 14px;
}

.footer-heading {
  margin-bottom: 14px;
  color: var(--color-panel);
  font-size: 14px;
  font-weight: 800;
}

.footer-links {
  display: grid;
  gap: 8px;
}

.footer-links a {
  display: inline-flex;
  width: fit-content;
  max-width: 100%;
  padding-block: 3px;
  font-size: 13px;
}

.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--color-panel);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 22px;
  padding-bottom: 22px;
  border-top: 1px solid var(--color-white-border);
  font-size: 12px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.reveal {
  transition: opacity var(--transition-reveal), transform var(--transition-reveal);
}

.reveal.pending {
  opacity: 0;
  transform: translateY(16px);
}

.reveal.shown {
  opacity: 1;
  transform: none;
}

body:has(.toc-tabs) section[id] {
  scroll-margin-top: var(--toc-offset);
}

.prose {
  overflow-wrap: break-word;
}

.prose h2 {
  margin-top: 2em;
}

.prose h3 {
  margin-top: 1.6em;
}

.prose blockquote {
  margin-inline: 0;
}

.prose ol.steps {
  padding-left: 0;
  list-style: none;
  counter-reset: steps;
}

.prose ol.steps > li {
  position: relative;
  min-height: 42px;
  padding-left: 52px;
  counter-increment: steps;
}

.prose ol.steps > li::before {
  position: absolute;
  top: 0;
  left: 0;
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  color: var(--color-panel);
  content: counter(steps);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 800;
}

.tilt,
.tilt-card {
  transform: rotate(-0.45deg);
}

@media (max-width: 1180px) {
  .desktop-nav {
    gap: 14px;
  }

  .desktop-nav a {
    font-size: 12px;
  }

  .brand-local {
    display: none;
  }
}

@media (max-width: 980px) {
  .desktop-nav,
  .language-menu {
    display: none;
  }

  .header-tools {
    margin-left: auto;
  }

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

  .footer-grid {
    grid-template-columns: 1.2fr 1fr 1fr;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 68px;
    --toc-offset: 82px;
  }

  h1,
  .hero-title {
    font-size: clamp(28px, 9.4vw, 40px);
    line-height: 1.12;
  }

  h2 {
    font-size: clamp(27px, 7.5vw, 38px);
  }

  .header-shell {
    gap: 10px;
  }

  .site-brand img {
    width: 38px;
    height: 38px;
    flex-basis: 38px;
  }

  .brand-main {
    font-size: 18px;
  }

  .header-login {
    min-height: 42px;
    padding-inline: 14px;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 34px 24px;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

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

@media (max-width: 640px) {
  :root {
    --gutter: 16px;
  }

  body {
    overflow-x: clip;
  }

  .wrap,
  .reading-wrap {
    width: 100%;
    padding-inline: var(--gutter);
  }

  .section {
    padding-top: 64px;
    padding-bottom: 64px;
  }

  .button-row {
    align-items: stretch;
    flex-direction: column;
  }

  .button-row .button {
    width: 100%;
  }

  .panel,
  .card {
    border-radius: var(--radius-card-inner);
  }

  .tilt,
  .tilt-card,
  [class*="tilt"] {
    transform: none;
  }

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

  .footer-brand {
    grid-column: auto;
  }
}

@media (max-width: 390px) {
  .brand-copy {
    display: none;
  }

  .header-login {
    padding-inline: 12px;
  }
}

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

  *,
  *::before,
  *::after {
    transition: none !important;
  }

  .reveal,
  .reveal.pending {
    opacity: 1 !important;
    transform: none !important;
  }
}