:root {
  --color-bg: #F3F8FB;
  --color-panel: #FFFFFF;
  --color-panel-soft: #E9F0F4;
  --color-panel-blue: #DCEBFA;
  --color-panel-blue-deep: #CFE2F6;
  --color-border: #D2E0E8;
  --color-accent: #2D72E8;
  --color-accent-dark: #184EA8;
  --color-text: #183442;
  --color-text-muted: #617986;
  --color-success: #238F78;
  --color-warn: #E8C928;
  --color-error: #D6535B;
  --color-white-soft: rgba(255, 255, 255, 0.78);
  --color-white-strong: rgba(255, 255, 255, 0.94);
  --color-white-faint: rgba(255, 255, 255, 0.46);
  --color-blue-faint: rgba(45, 114, 232, 0.08);
  --color-blue-soft: rgba(45, 114, 232, 0.14);
  --color-blue-medium: rgba(45, 114, 232, 0.28);
  --color-blue-shadow: rgba(24, 78, 168, 0.17);
  --color-deep-shadow: rgba(24, 52, 66, 0.14);
  --color-yellow-soft: rgba(232, 201, 40, 0.2);
  --color-yellow-shadow: rgba(232, 201, 40, 0.32);
  --color-green-soft: rgba(35, 143, 120, 0.12);
  --color-error-soft: rgba(214, 83, 91, 0.12);
  --color-cloud: rgba(255, 255, 255, 0.7);
  --color-map-land: rgba(45, 114, 232, 0.11);
  --color-map-line: rgba(45, 114, 232, 0.72);
  --color-map-grid: rgba(45, 114, 232, 0.08);
  --color-overlay: rgba(24, 52, 66, 0.34);
  --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-xs: 8px;
  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 25px;
  --radius-xl: 36px;
  --radius-pill: 999px;
  --shadow-header: 0 10px 34px rgba(24, 52, 66, 0.06);
  --shadow-panel: 0 30px 80px var(--color-deep-shadow);
  --shadow-card: 0 16px 38px rgba(24, 78, 168, 0.11);
  --shadow-button: 0 13px 26px var(--color-blue-shadow);
  --shadow-connect: 0 16px 30px var(--color-yellow-shadow);
  --shadow-float: 0 18px 42px rgba(24, 52, 66, 0.22);
  --page-width: 1340px;
  --reading-width: 768px;
  --gutter: clamp(18px, 4.7vw, 72px);
  --header-height: 70px;
  --section-space: clamp(70px, 9vw, 124px);
  --toc-offset: 82px;
  --transition-fast: 180ms ease;
  --transition-slow: 520ms cubic-bezier(0.2, 0.7, 0.2, 1);
}

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

html {
  width: 100%;
  min-width: 0;
  scroll-behavior: smooth;
  scroll-padding-top: var(--toc-offset);
}

html.nav-open {
  overflow: hidden;
}

body {
  width: 100%;
  min-width: 0;
  min-height: 100%;
  margin: 0;
  overflow-x: clip;
  color: var(--color-text);
  background:
    radial-gradient(ellipse at 78% 5%, var(--color-cloud) 0%, var(--color-white-faint) 25%, transparent 51%),
    radial-gradient(ellipse at 8% 72%, var(--color-white-strong) 0%, transparent 44%),
    linear-gradient(145deg, var(--color-bg) 4%, var(--color-panel-blue) 61%, var(--color-bg) 100%);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -2;
  content: "";
  pointer-events: none;
  background-image:
    linear-gradient(var(--color-map-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-map-grid) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.45;
  mask-image: linear-gradient(to bottom, transparent 7%, black 46%, transparent 100%);
}

body::after {
  position: fixed;
  top: 108px;
  right: -90px;
  z-index: -1;
  width: 660px;
  height: 190px;
  content: "";
  pointer-events: none;
  border-radius: var(--radius-pill);
  background:
    radial-gradient(ellipse at 18% 58%, var(--color-cloud) 0%, var(--color-cloud) 21%, transparent 22%),
    radial-gradient(ellipse at 42% 42%, var(--color-cloud) 0%, var(--color-cloud) 28%, transparent 29%),
    radial-gradient(ellipse at 68% 57%, var(--color-cloud) 0%, var(--color-cloud) 24%, transparent 25%);
  filter: blur(19px);
  opacity: 0.85;
}

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

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

img {
  height: auto;
}

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

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

button {
  border: 0;
}

a {
  color: var(--color-accent-dark);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

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

p,
ul,
ol,
blockquote,
pre,
table {
  margin-top: 0;
  margin-bottom: 1.25em;
}

ul,
ol {
  padding-left: 1.4em;
}

li + li {
  margin-top: 0.4em;
}

h1,
h2,
h3,
h4 {
  margin-top: 0;
  color: var(--color-text);
  font-family: var(--font-display);
  line-height: 1.12;
  text-wrap: balance;
}

h1 {
  margin-bottom: 0.32em;
  font-size: clamp(44px, 5.1vw, 68px);
  font-weight: 830;
  letter-spacing: -0.058em;
}

h2 {
  margin-bottom: 0.55em;
  font-size: clamp(30px, 3.5vw, 46px);
  font-weight: 790;
  letter-spacing: -0.04em;
}

h3 {
  margin-bottom: 0.55em;
  font-size: clamp(21px, 2.2vw, 28px);
  font-weight: 750;
  letter-spacing: -0.025em;
}

h4 {
  margin-bottom: 0.5em;
  font-size: 18px;
  font-weight: 730;
}

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

code {
  padding: 0.12em 0.38em;
  border-radius: var(--radius-xs);
  background: var(--color-panel-soft);
  font-size: 0.9em;
}

pre {
  max-width: 100%;
  padding: 20px;
  overflow-x: auto;
  border-radius: var(--radius-md);
  background: var(--color-text);
  color: var(--color-panel);
  font-family: var(--font-mono);
  line-height: 1.65;
  overscroll-behavior-inline: contain;
  -webkit-overflow-scrolling: touch;
}

pre code {
  padding: 0;
  background: transparent;
  color: inherit;
  overflow-wrap: normal;
  white-space: pre;
}

hr {
  height: 1px;
  margin: 40px 0;
  border: 0;
  background: var(--color-border);
}

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

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

.wrap {
  max-width: calc(var(--page-width) + (var(--gutter) * 2));
}

.reading-wrap {
  max-width: calc(var(--reading-width) + (var(--gutter) * 2));
}

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

.section-tight {
  padding-top: clamp(44px, 6vw, 72px);
  padding-bottom: clamp(44px, 6vw, 72px);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 38px;
}

.section-heading p {
  color: var(--color-text-muted);
  font-size: 17px;
}

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

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

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.surface,
.card,
.panel {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: var(--color-panel);
}

.card,
.panel {
  padding: clamp(22px, 3vw, 34px);
  box-shadow: var(--shadow-card);
}

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

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

.eyebrow,
.badge,
.tag {
  display: inline-flex;
  align-items: center;
  max-width: 100%;
  min-height: 28px;
  overflow: hidden;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 720;
  line-height: 1.2;
  text-overflow: ellipsis;
}

.eyebrow {
  gap: 8px;
  padding: 0 12px;
  color: var(--color-accent-dark);
  background: var(--color-panel-blue);
  letter-spacing: 0.035em;
}

.eyebrow-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: var(--radius-pill);
  background: var(--color-success);
  box-shadow: 0 0 0 4px var(--color-green-soft);
}

.badge,
.tag {
  padding: 6px 11px;
  white-space: nowrap;
}

.badge {
  color: var(--color-accent-dark);
  background: var(--color-panel-blue);
}

.badge-success {
  color: var(--color-success);
  background: var(--color-green-soft);
}

.badge-warn {
  color: var(--color-text);
  background: var(--color-yellow-soft);
}

.badge-error {
  color: var(--color-error);
  background: var(--color-error-soft);
}

.tag {
  color: var(--color-text-muted);
  background: var(--color-panel-soft);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 46px;
  padding: 0 20px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 14px;
  font-weight: 740;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.button svg {
  width: 17px;
  height: 17px;
  flex: 0 0 auto;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  color: var(--color-panel);
  background: var(--color-accent);
  box-shadow: var(--shadow-button);
}

.button-primary:hover {
  color: var(--color-panel);
  background: var(--color-accent-dark);
}

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

.button-secondary:hover {
  color: var(--color-accent-dark);
  background: var(--color-panel-blue);
}

.button-quiet {
  color: var(--color-text-muted);
  background: var(--color-white-faint);
}

.button:focus-visible,
.nav-link:focus-visible,
.language-trigger:focus-visible,
.menu-toggle:focus-visible,
.footer-link:focus-visible {
  outline: 3px solid var(--color-blue-medium);
  outline-offset: 3px;
}

.button[disabled],
.button.is-disabled {
  cursor: not-allowed;
  opacity: 0.5;
  transform: none;
  box-shadow: none;
}

.site-header {
  position: relative;
  z-index: 50;
  height: var(--header-height);
  padding-inline: var(--gutter);
  background: var(--color-white-soft);
  box-shadow: var(--shadow-header);
  backdrop-filter: blur(24px) saturate(130%);
}

.header-inner {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: var(--page-width);
  height: 100%;
  margin-inline: auto;
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 11px;
  min-width: 178px;
  color: var(--color-text);
  text-decoration: none;
}

.brand:hover {
  color: var(--color-text);
}

.brand-logo {
  width: 36px;
  height: 36px;
  flex: 0 0 auto;
  object-fit: contain;
}

.brand-names {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  min-width: 0;
  white-space: nowrap;
}

.brand-word {
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 800;
  letter-spacing: -0.045em;
}

.brand-local {
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 560;
  letter-spacing: 0.035em;
}

.primary-nav {
  display: flex;
  align-self: stretch;
  align-items: center;
  justify-content: center;
  gap: clamp(13px, 1.8vw, 23px);
  margin-left: auto;
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  height: 100%;
  color: var(--color-text-muted);
  font-size: 14px;
  font-weight: 620;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition-fast);
}

.nav-link::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 3px;
  content: "";
  border-radius: var(--radius-pill) var(--radius-pill) 0 0;
  background: var(--color-accent);
  opacity: 0;
  transform: scaleX(0.42);
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: var(--color-accent-dark);
}

.nav-link[aria-current="page"]::after {
  opacity: 1;
  transform: scaleX(1);
}

.header-tools {
  position: relative;
  display: flex;
  align-items: center;
  gap: 9px;
  margin-left: 22px;
}

.language-box {
  position: relative;
}

.language-trigger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 38px;
  padding: 0 12px;
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  background: var(--color-white-faint);
  cursor: pointer;
  font-size: 13px;
  font-weight: 620;
  white-space: nowrap;
}

.language-trigger svg {
  width: 15px;
  height: 15px;
}

.language-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 60;
  width: 166px;
  padding: 8px;
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: var(--shadow-card);
}

.language-menu[hidden] {
  display: none;
}

.language-menu a {
  display: flex;
  align-items: center;
  min-height: 42px;
  padding: 0 11px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 620;
  text-decoration: none;
}

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

.login-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 19px;
  color: var(--color-panel);
  border-radius: var(--radius-sm);
  background: var(--color-accent-dark);
  box-shadow: var(--shadow-button);
  font-size: 14px;
  font-weight: 720;
  text-decoration: none;
  white-space: nowrap;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.login-button:hover {
  color: var(--color-panel);
  background: var(--color-accent);
  transform: translateY(-2px);
}

.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0;
  border-radius: var(--radius-sm);
  background: var(--color-panel-soft);
  cursor: pointer;
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  width: 20px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-text);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.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;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines {
  background: transparent;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::before {
  top: 0;
  transform: rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::after {
  top: 0;
  transform: rotate(-45deg);
}

.mobile-nav {
  position: absolute;
  top: var(--header-height);
  right: 0;
  left: 0;
  z-index: 70;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  padding: 12px var(--gutter) 20px;
  overflow-y: auto;
  overscroll-behavior: contain;
  background: var(--color-panel);
  box-shadow: var(--shadow-card);
}

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

.mobile-nav a {
  display: flex;
  align-items: center;
  width: 100%;
  min-height: 48px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-weight: 680;
  text-decoration: none;
}

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

.mobile-nav-languages {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--color-border);
}

.mobile-nav-label {
  padding: 8px 12px 4px;
  color: var(--color-text-muted);
  font-size: 12px;
  font-weight: 720;
  letter-spacing: 0.06em;
}

.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 40;
  display: none;
  background: var(--color-overlay);
}

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

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

.footer-grid {
  display: grid;
  grid-template-columns: minmax(240px, 1.3fr) repeat(3, minmax(150px, 0.8fr));
  gap: 44px;
}

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

.footer-brand-head {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--color-text);
  text-decoration: none;
}

.footer-brand-head img {
  width: 38px;
  height: 38px;
}

.footer-brand-head strong {
  font-size: 21px;
}

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

.footer-title {
  margin-bottom: 15px;
  color: var(--color-text);
  font-size: 13px;
  font-weight: 760;
  letter-spacing: 0.07em;
}

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

.footer-link {
  width: fit-content;
  color: var(--color-text-muted);
  font-size: 14px;
  text-decoration: none;
}

.footer-link:hover {
  color: var(--color-accent-dark);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 54px;
  padding-top: 22px;
  padding-bottom: 28px;
  border-top: 1px solid var(--color-border);
  font-size: 13px;
}

.footer-legal,
.footer-languages {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
}

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

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

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

.tilt,
.tilt-card {
  transform: rotate(-0.35deg);
}

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

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

.prose h2 {
  margin-top: 2.2em;
}

.prose h3 {
  margin-top: 1.7em;
}

.prose a {
  overflow-wrap: anywhere;
}

.prose blockquote {
  margin-inline: 0;
}

.prose table,
.data-table {
  width: 100%;
  border-collapse: collapse;
}

.prose th,
.prose td,
.data-table th,
.data-table td {
  padding: 13px 15px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
}

.prose th,
.data-table th {
  color: var(--color-text);
  background: var(--color-panel-soft);
  font-size: 13px;
  font-weight: 740;
}

body:has(.toc-tabs) section[id] {
  scroll-margin-top: calc(var(--toc-offset) + 18px);
}

@media (max-width: 1120px) {
  .primary-nav {
    gap: 12px;
  }

  .brand {
    min-width: auto;
  }

  .brand-local {
    display: none;
  }

  .language-trigger span {
    display: none;
  }
}

@media (max-width: 900px) {
  .primary-nav {
    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: 640px) {
  :root {
    --gutter: 18px;
    --header-height: 64px;
    --toc-offset: 74px;
  }

  body::after {
    right: -360px;
    width: 520px;
  }

  h1 {
    font-size: clamp(38px, 11.5vw, 52px);
    line-height: 1.02;
    letter-spacing: -0.048em;
  }

  h2 {
    font-size: clamp(28px, 8vw, 36px);
  }

  .site-header {
    padding-inline: var(--gutter);
  }

  .brand {
    gap: 8px;
  }

  .brand-logo {
    width: 30px;
    height: 30px;
  }

  .brand-word {
    font-size: 19px;
  }

  .brand-local,
  .language-box {
    display: none;
  }

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

  .login-button {
    min-height: 38px;
    padding: 0 13px;
    font-size: 13px;
  }

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

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

  .section-tight {
    padding-top: 42px;
    padding-bottom: 42px;
  }

  .button {
    min-height: 45px;
    padding-inline: 17px;
  }

  .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;
  }

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

  .prose > .data-table {
    display: block;
    max-width: 100%;
    min-width: 0;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
}

@media (max-width: 390px) {
  :root {
    --gutter: 16px;
  }

  .brand-logo {
    width: 28px;
    height: 28px;
  }

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

  .header-tools {
    gap: 5px;
  }

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

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

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

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