:root {
  --color-bg: #FFFFFF;
  --color-panel: #F7F7F8;
  --color-panel-strong: #EEEEF1;
  --color-border: #E3E3E8;
  --color-accent: #0097A7;
  --color-accent-dark: #00707D;
  --color-accent-soft: rgba(0, 151, 167, .12);
  --color-text: #16161A;
  --color-muted: #6A6A75;
  --color-success: #1F9D55;
  --color-warning: #D97706;
  --color-error: #D92D20;
  --color-focus: #0097A7;
  --color-overlay: rgba(22, 22, 26, .38);
  --color-shadow-soft: rgba(22, 22, 26, .06);
  --color-shadow-deep: rgba(22, 22, 26, .16);
  --color-white-soft: rgba(255, 255, 255, .9);
  --font-display: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, 'Noto Sans SC', monospace;
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-pill: 999px;
  --shadow-low: 0 1px 2px var(--color-shadow-soft), 0 8px 24px var(--color-shadow-soft);
  --shadow-card: 0 1px 2px var(--color-shadow-soft), 0 22px 44px -14px var(--color-shadow-deep);
  --header-height: 68px;
  --toc-height: 54px;
  --content-max: 1320px;
  --reading-max: 820px;
  --gutter: 40px;
  --space-section: 88px;
  --transition-fast: 150ms ease;
}
*,
*::before,
*::after {
  box-sizing: border-box;
}
html {
  margin: 0;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
}
html.nav-open {
  overflow: hidden;
}
body {
  min-width: 320px;
  margin: 0;
  overflow-x: clip;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
body,
button,
input,
select,
textarea {
  font-family: var(--font-body);
}
img,
svg {
  max-width: 100%;
}
img {
  display: block;
  height: auto;
}
svg {
  display: inline-block;
  vertical-align: middle;
}
a {
  color: inherit;
  text-decoration: none;
}
button,
input,
select,
textarea {
  color: inherit;
  font: inherit;
}
button,
summary {
  cursor: pointer;
}
button {
  border: 0;
}
ul,
ol {
  padding-left: 1.25rem;
}
p,
h1,
h2,
h3,
h4,
ul,
ol,
blockquote,
pre,
figure {
  margin-top: 0;
}
h1,
h2,
h3,
h4 {
  color: var(--color-text);
  font-family: var(--font-display);
  text-wrap: balance;
}
h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 5vw, 68px);
  font-weight: 900;
  letter-spacing: -.015em;
  line-height: 1.1;
}
h2 {
  margin-bottom: 18px;
  font-size: clamp(34px, 4vw, 48px);
  font-weight: 850;
  letter-spacing: -.012em;
  line-height: 1.15;
}
h3 {
  margin-bottom: 12px;
  font-size: clamp(20px, 2vw, 25px);
  font-weight: 750;
  line-height: 1.25;
}
p {
  margin-bottom: 18px;
}
strong {
  font-weight: 700;
}
code,
kbd,
samp {
  font-family: var(--font-mono);
}
:not(pre) > code {
  padding: .12em .35em;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  background: var(--color-panel);
  font-size: .9em;
}
pre {
  max-width: 100%;
  padding: 18px;
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-text);
  color: var(--color-bg);
  font: 13px/1.65 var(--font-mono);
  -webkit-overflow-scrolling: touch;
}
pre code {
  white-space: pre;
}
::selection {
  background: var(--color-accent-soft);
  color: var(--color-text);
}
:where(a, button, input, select, textarea, summary, [role="tab"]):focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
}
.no-break {
  white-space: nowrap;
}
.text-accent {
  color: var(--color-accent);
}
.text-muted {
  color: var(--color-muted);
}
.mono {
  font-family: var(--font-mono);
}
.wrap {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading {
  width: 100%;
  max-width: calc(var(--reading-max) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section {
  padding-top: var(--space-section);
  padding-bottom: var(--space-section);
  overflow-x: clip;
}
.section-panel {
  border-block: 1px solid var(--color-border);
  background: var(--color-panel);
}
.section-head {
  max-width: 760px;
  margin-bottom: 38px;
}
.section-kicker {
  margin-bottom: 10px;
  color: var(--color-accent-dark);
  font: 700 12px/1.4 var(--font-mono);
  letter-spacing: .08em;
  text-transform: uppercase;
}
.section-lede {
  color: var(--color-muted);
  font-size: 18px;
  line-height: 1.7;
}
.panel,
.card {
  min-width: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
}
.panel {
  padding: 24px;
}
.card {
  padding: 26px;
  box-shadow: var(--shadow-low);
}
.status-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--color-accent);
}
.status-dot.is-success {
  background: var(--color-success);
}
.status-dot.is-warning {
  background: var(--color-warning);
}
.status-dot.is-error {
  background: var(--color-error);
}
.badge,
.chip {
  display: inline-flex;
  min-height: 26px;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  padding: 4px 10px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-text);
  font-size: 12px;
  font-weight: 650;
  line-height: 1.3;
}
.chip {
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-weight: 500;
}
.chip-accent {
  border-color: var(--color-accent-soft);
  background: var(--color-accent-soft);
  color: var(--color-accent-dark);
}
.button,
.btn {
  display: inline-flex;
  min-width: 24px;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast), opacity var(--transition-fast);
}
.button:hover,
.btn:hover {
  transform: translateY(-1px);
}
.button-primary,
.btn-primary {
  background: var(--color-text);
  color: var(--color-bg);
  box-shadow: var(--shadow-low);
}
.button-primary:hover,
.btn-primary:hover {
  opacity: .9;
}
.button-secondary,
.btn-secondary {
  border-color: var(--color-border);
  background: var(--color-bg);
  color: var(--color-text);
}
.button-secondary:hover,
.btn-secondary:hover {
  background: var(--color-panel);
}
.button-accent,
.btn-accent {
  background: var(--color-accent);
  color: var(--color-bg);
}
.button[aria-disabled="true"],
.button:disabled,
.btn[aria-disabled="true"],
.btn:disabled {
  cursor: not-allowed;
  opacity: .48;
  transform: none;
}
.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}
.reveal {
  transition: opacity .62s ease, transform .62s ease;
}
.reveal.pending {
  opacity: 0;
  transform: translateY(16px);
}
.reveal.shown {
  opacity: 1;
  transform: none;
}
.site-header {
  position: relative;
  z-index: 80;
  height: var(--header-height);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}
.header-inner {
  display: flex;
  height: 100%;
  align-items: center;
  gap: 24px;
}
.site-brand {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}
.site-brand img {
  width: 30px;
  height: 30px;
}
.brand-word {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 850;
  letter-spacing: -.01em;
}
.brand-local {
  color: var(--color-muted);
  font-weight: 600;
}
.desktop-nav {
  display: flex;
  height: var(--header-height);
  align-items: stretch;
  gap: 2px;
  margin-left: 8px;
}
.desktop-nav a {
  position: relative;
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding-inline: 13px;
  color: var(--color-muted);
  font-size: 15px;
  font-weight: 550;
}
.desktop-nav a:hover,
.desktop-nav a.is-active {
  color: var(--color-text);
}
.desktop-nav a.is-active {
  font-weight: 700;
}
.desktop-nav a.is-active::after {
  position: absolute;
  right: 13px;
  bottom: -1px;
  left: 13px;
  height: 2px;
  border-radius: 2px 2px 0 0;
  background: var(--color-accent);
  content: "";
}
.header-tools {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
}
.language-switch {
  position: relative;
}
.language-button {
  display: inline-flex;
  min-width: 44px;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 7px 11px;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-muted);
  font-size: 14px;
}
.language-button:hover {
  background: var(--color-panel);
  color: var(--color-text);
}
.language-menu {
  position: absolute;
  top: calc(100% + 9px);
  right: 0;
  z-index: 95;
  display: none;
  width: 164px;
  padding: 6px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  box-shadow: var(--shadow-card);
}
.language-switch.is-open .language-menu {
  display: block;
}
.language-menu a {
  display: flex;
  min-height: 40px;
  align-items: center;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--color-muted);
}
.language-menu a:hover,
.language-menu a[aria-current="true"] {
  background: var(--color-panel);
  color: var(--color-text);
}
.header-login {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  padding: 7px 18px;
  border-radius: var(--radius-sm);
  background: var(--color-text);
  color: var(--color-bg);
  font-size: 14px;
  font-weight: 700;
}
.menu-toggle {
  display: none;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--color-panel);
}
.menu-toggle svg {
  width: 20px;
  height: 20px;
}
.mobile-nav {
  position: absolute;
  top: var(--header-height);
  right: 0;
  left: 0;
  z-index: 92;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  overscroll-behavior: contain;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
  box-shadow: var(--shadow-card);
}
.mobile-nav.is-open {
  display: block;
}
.mobile-nav-inner {
  padding: 10px var(--gutter) 16px;
}
.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 46px;
  align-items: center;
  padding: 10px 8px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-muted);
}
.mobile-nav a.is-active {
  color: var(--color-accent-dark);
  font-weight: 700;
}
.mobile-language-label {
  display: block;
  padding: 14px 8px 5px;
  color: var(--color-muted);
  font: 600 11px/1.4 var(--font-mono);
}
.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 70;
  display: none;
  background: var(--color-overlay);
}
.nav-veil.is-open {
  display: block;
}
.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-panel);
}
.footer-main {
  display: grid;
  grid-template-columns: minmax(250px, 1.25fr) repeat(3, minmax(150px, 1fr));
  gap: 46px;
  padding-top: 56px;
  padding-bottom: 42px;
}
.footer-brand {
  min-width: 0;
}
.footer-brand-link {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 850;
}
.footer-brand-link img {
  width: 32px;
  height: 32px;
}
.footer-brand p {
  max-width: 360px;
  margin-top: 14px;
  color: var(--color-muted);
}
.footer-title {
  margin-bottom: 13px;
  font-size: 13px;
  font-weight: 750;
}
.footer-links {
  display: grid;
  gap: 3px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.footer-links a {
  display: inline-flex;
  min-height: 32px;
  align-items: center;
  color: var(--color-muted);
}
.footer-links a:hover {
  color: var(--color-accent-dark);
}
.footer-bottom {
  display: flex;
  min-height: 66px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-top: 14px;
  padding-bottom: 14px;
  border-top: 1px solid var(--color-border);
  color: var(--color-muted);
  font-size: 13px;
}
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}
.prose {
  color: var(--color-text);
  font-size: 16px;
  line-height: 1.78;
}
.prose > * {
  max-width: 100%;
}
.prose h2 {
  margin-top: 56px;
}
.prose h3 {
  margin-top: 34px;
}
.prose a {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
.prose img {
  border-radius: var(--radius-md);
}
.prose blockquote {
  margin-inline: 0;
}
@media (max-width: 1120px) {
  .desktop-nav a {
    padding-inline: 9px;
    font-size: 14px;
  }
  .desktop-nav a.is-active::after {
    right: 9px;
    left: 9px;
  }
}
@media (max-width: 1024px) {
  .desktop-nav,
  .language-switch {
    display: none;
  }
  .header-tools {
    margin-left: auto;
  }
  .menu-toggle {
    display: inline-flex;
  }
  .footer-main {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
@media (max-width: 768px) {
  :root {
    --gutter: 20px;
    --space-section: 64px;
  }
  h1 {
    font-size: clamp(32px, 9vw, 40px);
    letter-spacing: -.015em;
  }
  h2 {
    font-size: clamp(28px, 7vw, 36px);
  }
  .section-lede {
    font-size: 16px;
  }
  .footer-main {
    gap: 30px;
  }
}
@media (max-width: 640px) {
  :root {
    --gutter: 16px;
  }
  body {
    font-size: 14px;
  }
  .wrap,
  .reading {
    padding-inline: var(--gutter);
  }
  .no-break {
    white-space: normal;
  }
  .tilt,
  [class*="tilt"] {
    transform: none !important;
  }
  .button-row > .button,
  .button-row > .btn {
    flex: 1 1 auto;
  }
  .header-inner {
    gap: 10px;
  }
  .brand-word {
    font-size: 17px;
  }
  .header-login {
    padding-inline: 13px;
  }
  .footer-main {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0s !important;
    animation-duration: 0s !important;
    animation-iteration-count: 1 !important;
  }
  .reveal,
  .reveal.pending {
    opacity: 1;
    transform: none;
  }
}