:root {
  --color-page: #FFFFFF;
  --color-panel: #F7F7F8;
  --color-panel-strong: #F0F0F2;
  --color-line: #E5E5E8;
  --color-accent: #DE8348;
  --color-accent-deep: #B9622C;
  --color-gold: #D4A94A;
  --color-text: #1B1C1F;
  --color-text-soft: #5E6066;
  --color-success: #2E9E63;
  --color-warning: #C98A1F;
  --color-error: #C4453A;
  --color-flag-red: #C8332E;
  --color-flag-blue: #27437E;
  --color-overlay: rgba(27, 28, 31, 0.34);
  --color-shadow-soft: rgba(27, 28, 31, 0.04);
  --color-shadow: rgba(27, 28, 31, 0.07);
  --color-accent-shadow: rgba(222, 131, 72, 0.22);
  --color-accent-ring: rgba(212, 169, 74, 0.22);
  --color-accent-glow: rgba(222, 131, 72, 0.5);
  --gradient-warm: linear-gradient(118deg, var(--color-accent) 8%, var(--color-gold) 92%);
  --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', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
  --radius-xs: 6px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 22px;
  --radius-xl: 30px;
  --radius-pill: 999px;
  --shadow-card: 0 1px 2px var(--color-shadow-soft), 0 14px 36px var(--color-shadow);
  --shadow-button: 0 1px 2px var(--color-accent-ring), 0 8px 20px var(--color-accent-shadow);
  --shadow-floating: 0 4px 10px var(--color-shadow), 0 14px 32px var(--color-accent-shadow);
  --shadow-beacon: 0 0 0 3px var(--color-accent-ring), 0 0 14px 2px var(--color-accent-glow);
  --content-width: 1296px;
  --reading-width: 56rem;
  --header-height: 70px;
  --gutter: 44px;
  --section-space: 104px;
  --toc-offset: 86px;
  --motion-fast: 150ms;
  --motion-normal: 420ms;
}

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

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

html.nav-open {
  overflow: hidden;
}

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

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;
}

ul,
ol {
  margin: 0;
  padding: 0;
}

li {
  min-width: 0;
}

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

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

h1 {
  margin-bottom: 28px;
  font-size: clamp(52px, 5vw, 72px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(32px, 3.5vw, 48px);
  font-weight: 800;
  letter-spacing: -0.015em;
  line-height: 1.16;
}

h3 {
  margin-bottom: 14px;
  font-size: clamp(21px, 2vw, 28px);
  line-height: 1.25;
}

p {
  margin-bottom: 1.25em;
}

code {
  border-radius: var(--radius-xs);
  background: var(--color-panel-strong);
  font-family: var(--font-mono);
  font-size: 0.9em;
  overflow-wrap: anywhere;
  padding: 0.14em 0.38em;
}

pre {
  max-width: 100%;
  overflow-x: auto;
  border-radius: var(--radius-md);
  background: var(--color-text);
  color: var(--color-page);
  padding: 22px;
  -webkit-overflow-scrolling: touch;
}

pre code {
  display: block;
  min-width: max-content;
  background: transparent;
  color: inherit;
  overflow-wrap: normal;
  padding: 0;
}

table {
  border-collapse: collapse;
}

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

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

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

.section-head {
  max-width: 760px;
  margin-bottom: 44px;
}

.section-kicker {
  margin-bottom: 12px;
  color: var(--color-accent-deep);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

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

.nowrap-term {
  white-space: nowrap;
}

.gradient-text {
  background: var(--gradient-warm);
  color: transparent;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.card {
  padding: 28px;
}

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

.badge,
.tag,
.fact-chip {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background: var(--color-page);
  color: var(--color-text-soft);
  font-size: 13px;
  font-weight: 650;
  line-height: 1.3;
  overflow: hidden;
  padding: 7px 14px;
}

.badge-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: var(--radius-pill);
  background: var(--gradient-warm);
}

.btn {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 700;
  line-height: 1;
  padding: 0 28px;
  transition: transform var(--motion-fast), border-color var(--motion-fast), background var(--motion-fast), box-shadow var(--motion-fast);
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:focus-visible,
.site-nav a:focus-visible,
.lang-button:focus-visible,
.menu-toggle:focus-visible {
  outline: 3px solid var(--color-accent-ring);
  outline-offset: 3px;
}

.btn-primary {
  background: var(--gradient-warm);
  box-shadow: var(--shadow-button);
  color: var(--color-page);
}

.btn-secondary {
  border-color: var(--color-line);
  background: var(--color-page);
  color: var(--color-text);
}

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

.btn-small {
  min-height: 40px;
  padding-inline: 20px;
}

.site-head {
  position: relative;
  z-index: 100;
  border-bottom: 1px solid var(--color-line);
  background: var(--color-page);
}

.head-inner {
  display: flex;
  height: var(--header-height);
  align-items: center;
  gap: 34px;
}

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

.brand img {
  width: 30px;
  height: 30px;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.brand-local {
  color: var(--color-text-soft);
  font-size: 13px;
  font-weight: 500;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-left: 18px;
}

.site-nav a {
  color: var(--color-text-soft);
  font-size: 14px;
  font-weight: 550;
  transition: color var(--motion-fast);
  white-space: nowrap;
}

.site-nav a:hover,
.site-nav a.is-active {
  color: var(--color-text);
}

.site-nav a.is-active {
  font-weight: 750;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 13px;
  margin-left: auto;
}

.login-button {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background: var(--color-page);
  font-size: 14px;
  font-weight: 650;
  padding-inline: 21px;
}

.login-button:hover {
  border-color: var(--color-accent);
  background: var(--color-panel);
}

.language-menu {
  position: relative;
}

.lang-button {
  min-height: 40px;
  border: 0;
  background: transparent;
  color: var(--color-text-soft);
  font-size: 13px;
  padding: 0 8px;
}

.lang-list {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 120;
  display: none;
  width: 176px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-page);
  box-shadow: var(--shadow-card);
  list-style: none;
  padding: 7px;
}

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

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

.lang-list a:hover,
.lang-list a[aria-current="true"] {
  background: var(--color-panel);
  color: var(--color-text);
}

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

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

.menu-toggle {
  flex-direction: column;
  gap: 4px;
}

.menu-toggle[aria-expanded="true"] span {
  opacity: 0;
}

.menu-toggle[aria-expanded="true"]::before {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"]::after {
  transform: translateY(-6px) rotate(-45deg);
}

.mobile-drawer {
  display: none;
}

.mobile-veil {
  display: none;
}

.site-footer {
  border-top: 1px solid var(--color-line);
  background: var(--color-panel);
}

.footer-main {
  display: grid;
  grid-template-columns: 1.35fr 1fr 1.2fr 0.8fr;
  gap: 44px;
  padding-top: 68px;
  padding-bottom: 52px;
}

.footer-brand p {
  max-width: 340px;
  margin-top: 18px;
  color: var(--color-text-soft);
  font-size: 14px;
}

.footer-title {
  margin-bottom: 16px;
  color: var(--color-text);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.footer-links {
  display: grid;
  gap: 10px;
  list-style: none;
}

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

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid var(--color-line);
  color: var(--color-text-soft);
  font-size: 12px;
  padding-top: 20px;
  padding-bottom: 24px;
}

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

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

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

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

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

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

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

@media (max-width: 1120px) {
  :root {
    --gutter: 28px;
  }

  .site-nav {
    gap: 18px;
    margin-left: 0;
  }

  .site-nav a {
    font-size: 13px;
  }

  .brand-local {
    display: none;
  }

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

@media (max-width: 860px) {
  .desktop-nav,
  .language-menu {
    display: none;
  }

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

  .menu-toggle {
    display: flex;
  }

  .mobile-veil {
    position: fixed;
    inset: var(--header-height) 0 0;
    z-index: 90;
    background: var(--color-overlay);
  }

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

  .mobile-drawer {
    position: absolute;
    top: var(--header-height);
    right: 0;
    left: 0;
    z-index: 110;
    max-height: calc(100dvh - var(--header-height));
    overflow-y: auto;
    overscroll-behavior: contain;
    border-bottom: 1px solid var(--color-line);
    background: var(--color-page);
    padding: 10px var(--gutter) 18px;
  }

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

  .mobile-drawer ul {
    list-style: none;
  }

  .mobile-drawer a {
    display: flex;
    width: 100%;
    min-height: 48px;
    align-items: center;
    border-bottom: 1px solid var(--color-panel-strong);
    color: var(--color-text-soft);
    font-weight: 650;
    padding: 10px 4px;
  }

  .mobile-languages {
    margin-top: 12px;
  }

  .mobile-languages strong {
    display: block;
    margin: 8px 4px;
    font-size: 12px;
  }
}

@media (max-width: 768px) {
  :root {
    --section-space: 76px;
  }

  h1 {
    font-size: clamp(28px, 9vw, 40px);
    line-height: 1.12;
  }

  h2 {
    font-size: clamp(28px, 8vw, 38px);
  }

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

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

@media (max-width: 640px) {
  :root {
    --gutter: 18px;
    --header-height: 64px;
  }

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

  .head-inner {
    height: var(--header-height);
    gap: 8px;
  }

  .brand img {
    width: 28px;
    height: 28px;
  }

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

  .brand-local {
    display: none;
  }

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

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

  .btn {
    width: 100%;
  }

  .card {
    padding: 22px 18px;
  }

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

  .absolute-decoration,
  .hero-watermark,
  .decorative-disc {
    display: none;
  }
}

@media (max-width: 360px) {
  :root {
    --gutter: 16px;
  }

  .brand-local {
    display: none;
  }

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

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

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