:root {
  --color-canvas: #FFFFFF;
  --color-panel: #F5F8F9;
  --color-panel-strong: #EBF0F2;
  --color-line: #D9E1E4;
  --color-accent: #C63D28;
  --color-accent-dark: #9E2E1D;
  --color-accent-soft: #F9ECE8;
  --color-ink: #152B33;
  --color-muted: #51656E;
  --color-success: #2E7D5B;
  --color-success-soft: #EAF5F0;
  --color-warning: #A9761B;
  --color-warning-soft: #FCF5E7;
  --color-error: #8F1F14;
  --color-error-soft: #F9EAE8;
  --color-glow: #E3EDF0;
  --color-shadow: rgba(21, 43, 51, 0.1);
  --color-shadow-soft: rgba(21, 43, 51, 0.06);
  --color-accent-shadow: rgba(198, 61, 40, 0.24);
  --color-overlay: rgba(21, 43, 51, 0.38);
  --color-flag-red: #CE2939;
  --color-flag-blue: #26418F;
  --color-korea-blue: #1E4390;

  --font-display: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', -apple-system, 'Segoe UI', 'PingFang SC', 'Hiragino Sans', 'Malgun Gothic', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', -apple-system, 'Segoe UI', 'PingFang SC', 'Hiragino Sans', 'Malgun Gothic', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Consolas, 'Courier New', monospace;

  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-control: 9px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-pill: 999px;

  --shadow-panel: 0 14px 34px var(--color-shadow-soft);
  --shadow-device: 0 26px 50px var(--color-shadow), 0 4px 12px var(--color-shadow-soft);
  --shadow-button: 0 10px 22px var(--color-accent-shadow);
  --shadow-float: 0 12px 28px var(--color-accent-shadow);

  --page-max: 1240px;
  --header-max: 1360px;
  --reading-max: 57rem;
  --gutter: clamp(16px, 3.2vw, 40px);
  --section-space: clamp(64px, 9vw, 112px);
  --header-height: 68px;
  --toc-offset: 82px;
  --transition-fast: 180ms ease;
  --transition-reveal: 560ms cubic-bezier(.22, .72, .28, 1);
}

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

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

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  margin: 0;
  overflow-x: clip;
  background: var(--color-canvas);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body,
header,
main,
footer,
section,
article,
aside,
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,
dl,
blockquote,
pre,
table {
  margin-top: 0;
}

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

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

:not(pre) > code {
  padding: 0.12em 0.34em;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-xs);
  background: var(--color-panel);
  color: var(--color-ink);
  font-size: 0.9em;
}

pre {
  max-width: 100%;
  padding: 20px;
  overflow-x: auto;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-ink);
  color: var(--color-canvas);
  line-height: 1.7;
  -webkit-overflow-scrolling: touch;
}

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

hr {
  margin: 40px 0;
  border: 0;
  border-top: 1px solid var(--color-line);
}

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

:focus-visible {
  outline: 3px solid var(--color-accent-soft);
  outline-offset: 3px;
}

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

.wrap,
.container {
  max-width: var(--page-max);
}

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

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

.section-soft {
  background: var(--color-panel);
  border-block: 1px solid var(--color-line);
}

.section-head {
  max-width: 760px;
  margin-bottom: clamp(30px, 5vw, 54px);
}

.eyebrow {
  margin-bottom: 10px;
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 5.2vw, 72px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(34px, 4vw, 52px);
  font-weight: 800;
  letter-spacing: -0.018em;
  line-height: 1.16;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 750;
  line-height: 1.25;
}

h4 {
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 750;
  line-height: 1.35;
}

.lead {
  max-width: 720px;
  color: var(--color-muted);
  font-size: clamp(18px, 2vw, 21px);
  line-height: 1.75;
}

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

.text-accent,
.title-hit {
  color: var(--color-accent);
}

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

.badge,
.tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  max-width: 100%;
  padding: 6px 13px;
  overflow: hidden;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-muted);
  font-size: 13px;
  font-weight: 650;
  line-height: 1.2;
}

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

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

.btn {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 13px 28px;
  border: 1px solid transparent;
  border-radius: var(--radius-control);
  font-weight: 700;
  line-height: 1.15;
  text-align: center;
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.btn svg,
.icon-fixed {
  flex: 0 0 auto;
}

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

.btn-primary:hover {
  background: var(--color-accent-dark);
  transform: translateY(-1px);
}

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

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

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

.btn[aria-disabled="true"],
.btn:disabled {
  cursor: not-allowed;
  opacity: 0.5;
  transform: none;
  box-shadow: 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-lg);
  background: var(--color-canvas);
}

.panel {
  padding: clamp(24px, 4vw, 42px);
  box-shadow: var(--shadow-panel);
}

.card {
  padding: 24px;
}

.site-header {
  position: relative;
  z-index: 80;
  height: var(--header-height);
  border-bottom: 1px solid var(--color-line);
  background: var(--color-canvas);
}

.header-inner {
  display: flex;
  width: 100%;
  max-width: var(--header-max);
  height: var(--header-height);
  align-items: center;
  gap: 28px;
  margin-inline: auto;
  padding-inline: 32px;
}

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

.site-brand img {
  width: 32px;
  height: 32px;
}

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

.brand-primary {
  color: var(--color-ink);
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

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

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 25px;
  margin-left: 22px;
}

.desktop-nav a {
  padding-block: 8px;
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 550;
  white-space: nowrap;
  transition: color var(--transition-fast);
}

.desktop-nav a:hover,
.desktop-nav a.is-active,
.desktop-nav a[aria-current="page"] {
  color: var(--color-ink);
}

.desktop-nav a.is-active,
.desktop-nav a[aria-current="page"] {
  font-weight: 750;
}

.header-tools {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}

.language-control {
  position: relative;
}

.language-button {
  min-height: 44px;
  padding: 8px 5px;
  border: 0;
  background: transparent;
  color: var(--color-muted);
  font-size: 13px;
  white-space: nowrap;
}

.language-menu {
  position: absolute;
  top: calc(100% + 9px);
  right: 0;
  width: 170px;
  padding: 7px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-canvas);
  box-shadow: var(--shadow-panel);
}

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

.language-menu a {
  display: block;
  min-height: 42px;
  padding: 9px 11px;
  border-radius: var(--radius-sm);
  color: var(--color-muted);
  font-size: 14px;
}

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

.header-login {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  padding: 8px 19px;
  border: 1px solid var(--color-ink);
  border-radius: var(--radius-control);
  background: var(--color-canvas);
  color: var(--color-ink);
  font-size: 14px;
  font-weight: 700;
  white-space: nowrap;
}

.header-login:hover {
  background: var(--color-panel);
}

.menu-toggle {
  display: none;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-control);
  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-nav {
  display: none;
}

.nav-veil {
  display: none;
}

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

.footer-grid {
  display: grid;
  grid-template-columns: 1.45fr 1fr 1.15fr 0.8fr;
  gap: 46px;
  padding-top: 64px;
  padding-bottom: 50px;
}

.footer-brand-copy {
  max-width: 330px;
  margin-top: 18px;
  color: var(--color-muted);
  font-size: 14px;
}

.footer-title {
  margin-bottom: 16px;
  color: var(--color-ink);
  font-size: 14px;
  font-weight: 800;
}

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

.footer-links a {
  color: var(--color-muted);
  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-block: 22px;
  border-top: 1px solid var(--color-line);
  color: var(--color-muted);
  font-size: 13px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
}

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

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

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

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

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

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

.prose h2,
.prose h3 {
  scroll-margin-top: var(--toc-offset);
}

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

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

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

@media (max-width: 1120px) {
  .desktop-nav {
    gap: 16px;
    margin-left: 8px;
  }

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

  .brand-local {
    display: none;
  }
}

@media (max-width: 960px) {
  .header-inner {
    padding-inline: var(--gutter);
  }

  .desktop-nav,
  .language-control {
    display: none;
  }

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

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

  .mobile-nav {
    position: absolute;
    z-index: 83;
    top: var(--header-height);
    right: 0;
    left: 0;
    max-height: calc(100dvh - var(--header-height));
    padding: 10px var(--gutter) 20px;
    overflow-y: auto;
    overscroll-behavior: contain;
    border-bottom: 1px solid var(--color-line);
    background: var(--color-canvas);
    box-shadow: var(--shadow-panel);
  }

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

  .mobile-nav a {
    display: flex;
    width: 100%;
    min-height: 46px;
    align-items: center;
    padding: 11px 8px;
    border-bottom: 1px solid var(--color-line);
    color: var(--color-muted);
    font-weight: 650;
  }

  .mobile-nav a.is-active {
    color: var(--color-accent);
  }

  .mobile-language-title {
    padding: 18px 8px 4px;
    color: var(--color-muted);
    font-size: 12px;
    font-weight: 750;
  }

  .nav-veil {
    position: fixed;
    z-index: 70;
    inset: var(--header-height) 0 0;
    border: 0;
    background: var(--color-overlay);
  }

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

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

@media (max-width: 768px) {
  h1 {
    font-size: clamp(28px, 9.2vw, 40px);
    line-height: 1.12;
    letter-spacing: -0.018em;
  }

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

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

  .tilt,
  .tilt-card {
    transform: none;
  }

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

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

  .header-inner {
    gap: 10px;
  }

  .brand-local {
    display: none;
  }

  .header-login {
    padding-inline: 13px;
  }

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

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

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

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

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

  .absolute-decoration,
  .decorative-caption {
    display: none;
  }
}

@media (max-width: 380px) {
  .brand-primary {
    font-size: 16px;
  }

  .header-login {
    min-height: 38px;
    padding-inline: 10px;
    font-size: 13px;
  }
}

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

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

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