:root {
  --color-canvas: #FAFBF9;
  --color-panel: #FFFFFF;
  --color-panel-soft: #F3F7F5;
  --color-panel-accent: #EAF8F4;
  --color-border: #DCE3DF;
  --color-border-strong: #C8D4CE;
  --color-accent: #0AAE91;
  --color-accent-dark: #087A69;
  --color-accent-pale: #DDF5EF;
  --color-text: #141917;
  --color-muted: #65706B;
  --color-muted-light: #8B9691;
  --color-success: #0AAE91;
  --color-warn: #B97816;
  --color-error: #C94A43;
  --color-white: #FFFFFF;
  --color-transparent: transparent;
  --color-grid: rgba(20, 25, 23, 0.055);
  --color-globe: rgba(10, 174, 145, 0.18);
  --color-globe-soft: rgba(10, 174, 145, 0.09);
  --color-shadow: rgba(20, 25, 23, 0.08);
  --color-shadow-soft: rgba(20, 25, 23, 0.035);
  --color-accent-shadow: rgba(10, 174, 145, 0.18);
  --color-sheen: rgba(255, 255, 255, 0.52);
  --color-overlay: rgba(20, 25, 23, 0.24);
  --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: 5px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-pill: 999px;
  --shadow-device: 0 24px 60px var(--color-shadow), 0 3px 12px var(--color-shadow-soft);
  --shadow-button: 0 8px 22px var(--color-accent-shadow);
  --shadow-panel: 0 12px 36px var(--color-shadow-soft);
  --gradient-logo: linear-gradient(145deg, var(--color-accent), var(--color-accent-dark));
  --gradient-button: linear-gradient(180deg, var(--color-accent), var(--color-accent-dark));
  --gradient-atmosphere: radial-gradient(circle at center, var(--color-accent-pale) 0, var(--color-transparent) 66%);
  --gradient-sheen: linear-gradient(105deg, var(--color-transparent) 24%, var(--color-sheen) 48%, var(--color-transparent) 72%);
  --wrap: 1120px;
  --wrap-wide: 1320px;
  --reading: 768px;
  --gutter: 24px;
  --header-height: 66px;
  --section-space: 104px;
  --toc-top: 74px;
  --toc-clearance: 136px;
  --line-body: 1.72;
  --motion-fast: 160ms;
  --motion-base: 360ms;
}

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

html {
  min-width: 0;
  scroll-behavior: smooth;
  background: var(--color-canvas);
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 0;
  min-height: 100%;
  margin: 0;
  overflow-x: clip;
  background: var(--color-canvas);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: var(--line-body);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

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 {
  cursor: pointer;
}

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

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

p {
  margin-bottom: 1.15em;
}

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

li + li {
  margin-top: 0.35em;
}

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

code {
  overflow-wrap: anywhere;
}

pre {
  max-width: 100%;
  padding: 18px;
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel-soft);
  color: var(--color-text);
  -webkit-overflow-scrolling: touch;
}

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

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

th,
td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
}

th {
  color: var(--color-text);
  font-size: 13px;
  font-weight: 650;
}

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

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

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

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

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

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

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

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

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

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

.kicker {
  margin-bottom: 12px;
  color: var(--color-accent-dark);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 5.2vw, 72px);
  font-weight: 580;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(32px, 3.2vw, 46px);
  font-weight: 590;
  line-height: 1.16;
  letter-spacing: -0.018em;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(21px, 2vw, 27px);
  font-weight: 620;
  line-height: 1.3;
}

h4 {
  margin-bottom: 10px;
  font-size: 17px;
  font-weight: 650;
  line-height: 1.4;
}

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

.lead {
  max-width: 720px;
  color: var(--color-muted);
  font-size: clamp(17px, 1.8vw, 21px);
  line-height: 1.68;
}

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

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

.button,
.cta {
  min-height: 42px;
  padding: 0 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-shrink: 0;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-panel);
  color: var(--color-text);
  font-size: 14px;
  font-weight: 650;
  line-height: 1;
  white-space: nowrap;
  transition: transform var(--motion-fast) ease, border-color var(--motion-fast) ease, box-shadow var(--motion-fast) ease, background-color var(--motion-fast) ease;
}

.button:hover,
.cta:hover {
  transform: translateY(-1px);
}

.button-primary,
.cta-primary {
  position: relative;
  overflow: hidden;
  border-color: var(--color-accent-dark);
  background: var(--gradient-button);
  color: var(--color-white);
  box-shadow: var(--shadow-button);
}

.button-primary::after,
.cta-primary::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--gradient-sheen);
  transform: translateX(-110%);
  transition: transform 420ms ease;
}

.button-primary:hover::after,
.cta-primary:hover::after {
  transform: translateX(110%);
}

.button-secondary,
.cta-secondary {
  background: var(--color-panel);
  box-shadow: 0 2px 8px var(--color-shadow-soft);
}

.button-small {
  min-height: 36px;
  padding-inline: 14px;
  font-size: 13px;
}

.button:disabled,
.button[aria-disabled="true"] {
  cursor: not-allowed;
  opacity: 0.55;
  transform: none;
}

.button svg,
.cta svg,
.nav-link svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.badge,
.tag,
.fact-pill {
  max-width: 100%;
  min-height: 28px;
  padding: 0 11px;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  overflow: hidden;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-muted);
  font-size: 12px;
  font-weight: 600;
  text-overflow: ellipsis;
  white-space: nowrap;
}

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

.status-dot {
  width: 7px;
  height: 7px;
  flex-shrink: 0;
  border-radius: var(--radius-pill);
  background: var(--color-success);
  box-shadow: 0 0 0 3px var(--color-accent-pale);
}

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

.panel {
  padding: 28px;
}

.card {
  padding: 24px;
  transition: border-color var(--motion-fast) ease, transform var(--motion-fast) ease, box-shadow var(--motion-fast) ease;
}

.card:hover {
  border-color: var(--color-border-strong);
  transform: translateY(-2px);
  box-shadow: var(--shadow-panel);
}

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

.header-inner {
  width: min(var(--wrap-wide), calc(100% - 48px));
  height: 100%;
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: 22px;
}

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

.brand-logo {
  width: 34px;
  height: 34px;
  flex-shrink: 0;
}

.brand-name {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  color: var(--color-text);
  font-size: 17px;
  font-weight: 720;
  line-height: 1;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.brand-local {
  color: var(--color-muted);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0;
}

.primary-nav {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  min-height: 36px;
  padding: 0 9px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border-radius: var(--radius-sm);
  color: var(--color-muted);
  font-size: 13px;
  font-weight: 520;
  line-height: 1;
  white-space: nowrap;
  transition: color var(--motion-fast) ease, background-color var(--motion-fast) ease;
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  background: var(--color-panel-soft);
  color: var(--color-text);
}

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

.language-control {
  position: relative;
}

.language-button,
.login-button,
.menu-toggle {
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 620;
  white-space: nowrap;
}

.language-button {
  padding: 0 10px;
  border: 1px solid var(--color-transparent);
  background: var(--color-transparent);
  color: var(--color-muted);
}

.login-button {
  padding: 0 16px;
  border: 1px solid var(--color-border-strong);
  background: var(--color-panel);
  color: var(--color-text);
  box-shadow: 0 1px 2px var(--color-shadow-soft);
}

.language-menu {
  position: absolute;
  z-index: 70;
  top: calc(100% + 9px);
  right: 0;
  width: 156px;
  padding: 6px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel);
  box-shadow: var(--shadow-device);
}

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

.language-menu a {
  min-height: 40px;
  padding: 0 10px;
  display: flex;
  align-items: center;
  border-radius: var(--radius-xs);
  color: var(--color-muted);
  font-size: 13px;
}

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

.menu-toggle {
  display: none;
  width: 44px;
  min-width: 44px;
  min-height: 44px;
  padding: 0;
  border: 1px solid var(--color-border);
  background: var(--color-panel);
}

.menu-toggle svg {
  width: 20px;
  height: 20px;
}

.mobile-nav {
  display: none;
}

.mobile-veil {
  display: none;
}

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

.footer-main {
  padding-top: 72px;
  padding-bottom: 56px;
  display: grid;
  grid-template-columns: minmax(240px, 1.3fr) repeat(3, minmax(150px, 1fr));
  gap: 52px;
}

.footer-brand p {
  max-width: 330px;
  margin: 18px 0 0;
  color: var(--color-muted);
  font-size: 14px;
}

.footer-heading {
  margin-bottom: 16px;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 650;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

.footer-links a {
  width: fit-content;
  color: var(--color-muted);
  font-size: 14px;
}

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

.footer-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-keywords a {
  max-width: 100%;
  padding: 5px 9px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  background: var(--color-panel-soft);
  color: var(--color-muted);
  font-size: 12px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.footer-bottom {
  min-height: 64px;
  padding-top: 18px;
  padding-bottom: 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid var(--color-border);
  color: var(--color-muted-light);
  font-family: var(--font-mono);
  font-size: 11px;
}

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

.reveal {
  transition: opacity 520ms ease, transform 520ms ease;
}

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

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

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

.decorated-section,
.hero,
.promo-band {
  overflow-x: clip;
}

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

.prose h2,
.prose h3,
.prose h4,
.prose strong {
  color: var(--color-text);
}

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

.prose h3 {
  margin-top: 1.8em;
}

.prose a {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-color: var(--color-border-strong);
  text-underline-offset: 3px;
}

.prose blockquote {
  margin: 28px 0;
}

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

.prose ol.steps > li {
  position: relative;
  min-height: 34px;
  padding-left: 48px;
  counter-increment: guide-step;
}

.prose ol.steps > li::before {
  content: counter(guide-step, decimal-leading-zero);
  position: absolute;
  top: 0;
  left: 0;
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  color: var(--color-accent-dark);
  font-family: var(--font-mono);
  font-size: 10px;
}

@media (max-width: 1120px) {
  .primary-nav {
    display: none;
  }

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

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

  .mobile-veil {
    position: fixed;
    z-index: 40;
    inset: var(--header-height) 0 0;
    background: var(--color-overlay);
  }

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

  .mobile-nav {
    position: absolute;
    z-index: 60;
    top: var(--header-height);
    right: 0;
    left: 0;
    max-height: calc(100dvh - var(--header-height));
    padding: 12px var(--gutter) 18px;
    overflow-y: auto;
    overscroll-behavior: contain;
    border-bottom: 1px solid var(--color-border);
    background: var(--color-panel);
    box-shadow: var(--shadow-device);
  }

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

  .mobile-nav a {
    width: 100%;
    min-height: 48px;
    padding: 0 12px;
    display: flex;
    align-items: center;
    gap: 10px;
    border-bottom: 1px solid var(--color-border);
    color: var(--color-muted);
    font-size: 14px;
  }

  .mobile-nav a svg {
    width: 17px;
    height: 17px;
    flex-shrink: 0;
  }

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

  .mobile-language-links {
    padding-top: 10px;
  }

  .mobile-language-links a {
    min-height: 44px;
    border-bottom: 0;
  }
}

@media (max-width: 768px) {
  :root {
    --gutter: 18px;
    --section-space: 76px;
    --toc-top: 66px;
    --toc-clearance: 124px;
  }

  h1 {
    font-size: clamp(28px, 9.5vw, 40px);
    line-height: 1.12;
    letter-spacing: -0.018em;
  }

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

  .header-inner {
    width: 100%;
    padding-inline: var(--gutter);
    gap: 10px;
  }

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

  .header-tools {
    margin-left: auto;
    gap: 6px;
  }

  .login-button {
    min-height: 38px;
    padding-inline: 12px;
  }

  .footer-main {
    grid-template-columns: 1fr 1fr;
    gap: 38px 24px;
  }

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

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

  .absolute-label,
  .decorative-copy {
    display: none;
  }
}

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

  .section {
    padding-top: 68px;
    padding-bottom: 68px;
  }

  .section-compact {
    padding-top: 48px;
    padding-bottom: 48px;
  }

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

  .button,
  .cta {
    min-height: 40px;
    padding-inline: 15px;
    font-size: 13px;
  }

  .hero-actions .button,
  .hero-actions .cta {
    min-width: 108px;
    min-height: 38px;
    padding-inline: 14px;
    font-size: 13px;
  }

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

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

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

  th,
  td {
    padding: 12px;
  }
}

@media (max-width: 380px) {
  .brand-name {
    font-size: 15px;
  }

  .login-button {
    padding-inline: 10px;
    font-size: 12px;
  }

  .hero-actions {
    gap: 8px;
  }
}

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

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

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