:root {
  --color-canvas: #FFFFFF;
  --color-panel: #F6F7FA;
  --color-panel-strong: #EDEFF5;
  --color-line: #E2E5EC;
  --color-accent: #B4EF00;
  --color-route: #1B2A8F;
  --color-route-hover: #2E41C4;
  --color-ink: #0F1428;
  --color-muted: #5B6175;
  --color-success: #1FA55E;
  --color-warning: #FF7E1F;
  --color-error: #D93025;
  --color-white: #FFFFFF;
  --color-transparent: transparent;
  --color-route-shadow: rgba(27, 42, 143, .16);
  --color-route-shadow-soft: rgba(27, 42, 143, .08);
  --color-accent-glow: rgba(180, 239, 0, .45);
  --color-accent-ring: rgba(180, 239, 0, .25);
  --color-white-soft: rgba(255, 255, 255, .62);
  --color-white-faint: rgba(255, 255, 255, .14);
  --color-white-hover: rgba(255, 255, 255, .05);
  --font-display: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', -apple-system, 'PingFang SC', 'Hiragino Sans', 'Malgun Gothic', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', -apple-system, 'PingFang SC', 'Hiragino Sans', 'Malgun Gothic', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', monospace;
  --radius-xs: 6px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-board: 28px;
  --radius-pill: 999px;
  --shadow-board: 0 28px 64px var(--color-route-shadow), 0 6px 18px var(--color-route-shadow-soft);
  --shadow-raised: 0 16px 38px var(--color-route-shadow-soft);
  --content-width: 1328px;
  --reading-width: 820px;
  --gutter: 48px;
  --header-height: 72px;
  --section-space: 104px;
  --toc-offset: 88px;
  --motion-fast: 150ms;
  --motion-normal: 420ms;
}

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

html {
  background: var(--color-canvas);
  color: var(--color-ink);
  font-family: var(--font-body);
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}

html.nav-open {
  overflow: hidden;
}

body {
  margin: 0;
  min-width: 0;
  overflow-x: clip;
  background: var(--color-canvas);
  color: var(--color-ink);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

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

button,
summary {
  cursor: pointer;
}

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

p,
h1,
h2,
h3,
h4,
ul,
ol,
blockquote,
figure {
  margin-top: 0;
}

p:last-child,
ul:last-child,
ol:last-child,
blockquote:last-child {
  margin-bottom: 0;
}

ul,
ol {
  padding-left: 1.3em;
}

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

:not(pre) > code {
  overflow-wrap: anywhere;
  padding: .12em .35em;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-xs);
  background: var(--color-panel);
  font-size: .9em;
}

pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 20px;
  border-radius: var(--radius-sm);
  background: var(--color-ink);
  color: var(--color-white);
  -webkit-overflow-scrolling: touch;
}

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

table {
  border-collapse: collapse;
}

.wrap {
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.section {
  padding-top: var(--section-space);
  padding-bottom: var(--section-space);
  overflow-x: clip;
}

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

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 38px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--color-line);
}

.section-kicker,
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 14px;
  color: var(--color-route);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.section-kicker::before,
.eyebrow::before {
  width: 8px;
  height: 8px;
  flex-shrink: 0;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  content: "";
}

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

h1,
.hero-title {
  margin-bottom: 28px;
  font-size: clamp(52px, 5.1vw, 72px);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.1;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(32px, 3.2vw, 48px);
  font-weight: 800;
  line-height: 1.16;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(21px, 2vw, 28px);
  font-weight: 750;
  line-height: 1.25;
}

h4 {
  margin-bottom: 8px;
  font-size: 18px;
  line-height: 1.35;
}

.no-break {
  white-space: nowrap;
}

.lead {
  max-width: 720px;
  color: var(--color-muted);
  font-size: clamp(18px, 1.7vw, 21px);
  line-height: 1.7;
}

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

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

.badge,
.tag {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  max-width: 100%;
  min-height: 28px;
  padding: 4px 11px;
  overflow: hidden;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background: var(--color-canvas);
  color: var(--color-muted);
  font-size: 12px;
  font-weight: 650;
  line-height: 1.25;
}

.badge--accent {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: var(--color-ink);
}

.badge--warning {
  border-color: var(--color-warning);
  color: var(--color-warning);
}

.status-dot {
  width: 8px;
  height: 8px;
  flex-shrink: 0;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-ring);
}

.button,
.btn-primary,
.btn-secondary,
.btn-login {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border: 1px solid var(--color-transparent);
  border-radius: var(--radius-sm);
  padding: 11px 24px;
  font-weight: 700;
  line-height: 1.25;
  text-align: center;
  transition: transform var(--motion-fast) ease, background-color var(--motion-fast) ease, border-color var(--motion-fast) ease, box-shadow var(--motion-fast) ease, color var(--motion-fast) ease;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-ink);
  box-shadow: 0 2px 0 var(--color-route-shadow-soft);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px var(--color-accent-glow);
}

.btn-secondary {
  border-color: var(--color-ink);
  background: var(--color-canvas);
  color: var(--color-ink);
}

.btn-secondary:hover {
  background: var(--color-panel);
}

.btn-login {
  min-height: 40px;
  padding: 8px 22px;
  background: var(--color-route);
  color: var(--color-white);
  font-size: 14px;
}

.btn-login:hover {
  background: var(--color-route-hover);
}

.button:focus-visible,
.btn-primary:focus-visible,
.btn-secondary:focus-visible,
.btn-login:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
}

.button[aria-disabled="true"],
.button:disabled {
  cursor: not-allowed;
  opacity: .55;
  transform: none;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

.panel,
.card {
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-canvas);
}

.panel {
  padding: 28px;
}

.card {
  padding: 24px;
}

.site-header {
  position: relative;
  z-index: 50;
  border-bottom: 1px solid var(--color-line);
  background: var(--color-canvas);
}

.header-bar {
  display: flex;
  height: var(--header-height);
  align-items: center;
  gap: 28px;
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.brand-name {
  color: var(--color-ink);
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: .02em;
}

.brand-local {
  color: var(--color-muted);
  font-weight: 600;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: 16px;
}

.desktop-nav a {
  border-radius: var(--radius-pill);
  padding: 7px 14px;
  color: var(--color-muted);
  font-size: 14.5px;
  transition: color var(--motion-fast) ease, background-color var(--motion-fast) ease;
}

.desktop-nav a:hover {
  color: var(--color-ink);
}

.desktop-nav a.is-active {
  background: var(--color-panel-strong);
  color: var(--color-ink);
  font-weight: 650;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-left: auto;
}

.language-control {
  position: relative;
}

.language-button {
  min-height: 40px;
  border: 0;
  background: var(--color-transparent);
  color: var(--color-muted);
  font-size: 13.5px;
}

.language-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 70;
  display: none;
  width: 168px;
  padding: 7px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-canvas);
  box-shadow: var(--shadow-raised);
}

.language-control.is-open .language-menu {
  display: block;
}

.language-menu a {
  display: block;
  min-height: 42px;
  padding: 9px 11px;
  border-radius: var(--radius-xs);
  color: var(--color-muted);
}

.language-menu a:hover,
.language-menu a[aria-current="true"] {
  background: var(--color-panel);
  color: var(--color-ink);
}

.menu-toggle {
  display: none;
  width: 44px;
  min-width: 44px;
  height: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-canvas);
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  width: 19px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-ink);
}

.menu-toggle-lines {
  position: relative;
}

.menu-toggle-lines::before,
.menu-toggle-lines::after {
  position: absolute;
  left: 0;
  content: "";
}

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

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

.mobile-menu {
  position: absolute;
  top: var(--header-height);
  right: 0;
  left: 0;
  z-index: 65;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  padding: 12px var(--gutter) 20px;
  border-bottom: 1px solid var(--color-line);
  background: var(--color-canvas);
  overscroll-behavior: contain;
}

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

.mobile-menu a {
  display: flex;
  width: 100%;
  min-height: 48px;
  align-items: center;
  padding: 11px 12px;
  border-radius: var(--radius-sm);
  color: var(--color-muted);
}

.mobile-menu a:hover,
.mobile-menu a.is-active {
  background: var(--color-panel-strong);
  color: var(--color-ink);
}

.mobile-language-links {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--color-line);
}

.mobile-menu-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 40;
  display: none;
  border: 0;
  background: var(--color-route-shadow);
}

.mobile-menu-veil.is-open {
  display: block;
}

.site-footer {
  padding-top: 70px;
  background: var(--color-route);
  color: var(--color-white);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.15fr .8fr 1fr .8fr;
  gap: 46px;
  padding-bottom: 54px;
}

.footer-brand {
  max-width: 360px;
}

.footer-brand .brand-name,
.footer-brand .brand-local {
  color: var(--color-white);
}

.footer-brand p {
  margin-top: 18px;
  color: var(--color-white-soft);
}

.footer-title {
  margin-bottom: 16px;
  color: var(--color-white);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
}

.footer-links {
  display: grid;
  gap: 9px;
}

.footer-links a {
  color: var(--color-white-soft);
  font-size: 14px;
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-top: 22px;
  padding-bottom: 22px;
  border-top: 1px solid var(--color-white-faint);
  color: var(--color-white-soft);
  font-size: 13px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

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

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

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

.prose {
  color: var(--color-ink);
}

.prose > * {
  max-width: 100%;
}

.prose p,
.prose li {
  color: var(--color-muted);
}

.prose h2 {
  margin-top: 64px;
}

.prose h3 {
  margin-top: 38px;
}

.prose a {
  color: var(--color-route);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose img {
  height: auto;
  border-radius: var(--radius-md);
}

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

.prose ol.steps > li {
  position: relative;
  padding-left: 48px;
  counter-increment: guide-step;
}

.prose ol.steps > li::before {
  position: absolute;
  top: 0;
  left: 0;
  display: inline-flex;
  width: 32px;
  height: 32px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--color-route);
  color: var(--color-white);
  content: counter(guide-step);
  font-family: var(--font-mono);
  font-size: 12px;
}

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

@media (max-width: 1180px) {
  :root {
    --gutter: 32px;
  }

  .desktop-nav {
    display: none;
  }

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

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

  .language-control {
    display: none;
  }

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

@media (max-width: 768px) {
  :root {
    --gutter: 20px;
    --section-space: 72px;
    --toc-offset: 82px;
  }

  h1,
  .hero-title {
    font-size: clamp(32px, 9vw, 40px);
    letter-spacing: -.015em;
  }

  h2 {
    font-size: clamp(28px, 7vw, 36px);
  }

  .header-bar {
    gap: 10px;
  }

  .brand-name {
    font-size: 17px;
  }

  .btn-login {
    min-height: 38px;
    padding-inline: 15px;
  }

  .section-head {
    display: block;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

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

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

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

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

  .panel,
  .card {
    padding: 20px;
  }

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

  .header-tools {
    gap: 7px;
    margin-left: auto;
  }

  .brand-logo {
    width: 32px;
    height: 32px;
  }

  .mobile-menu {
    padding-inline: var(--gutter);
  }
}

@media (max-width: 360px) {
  .brand-name {
    font-size: 15px;
  }

  .btn-login {
    padding-inline: 11px;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

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