:root {
  --color-bg: #E4EBF4;
  --color-bg-top: #EDF2F8;
  --color-bg-bottom: #DCE5F0;
  --color-panel: #F3F7FB;
  --color-panel-sunk: #D6E0EC;
  --color-border: #C3D0DF;
  --color-border-soft: rgba(195, 208, 223, .6);
  --color-accent: #FFC81C;
  --color-accent-light: #FFD65A;
  --color-accent-dark: #D99E00;
  --color-accent-soft: rgba(255, 200, 28, .28);
  --color-accent-ring: rgba(255, 200, 28, .22);
  --color-accent-glow: rgba(217, 158, 0, .22);
  --color-text: #10172B;
  --color-brand-deep: #2A3B66;
  --color-muted: #5B6780;
  --color-faint: #93A0B8;
  --color-success: #1F9D5F;
  --color-warning: #D97C0B;
  --color-error: #D4374A;
  --color-grid: rgba(16, 23, 43, .04);
  --color-glow: rgba(247, 250, 253, .95);
  --color-highlight: rgba(255, 255, 255, .9);
  --color-window: #10172B;
  --color-window-top: #161E37;
  --color-window-card: rgba(255, 255, 255, .03);
  --color-window-row: rgba(255, 255, 255, .06);
  --color-window-line: rgba(255, 255, 255, .08);
  --color-window-line-strong: rgba(255, 255, 255, .16);
  --color-window-highlight: rgba(255, 255, 255, .12);
  --color-window-text: #E8EEF7;
  --color-window-muted: #8B98B2;
  --color-window-shadow: rgba(16, 23, 43, .18);
  --color-overlay: rgba(16, 23, 43, .48);
  --color-flag-red: #D7263D;
  --color-flag-white: #F7F9FC;
  --color-flag-blue: #1F3A93;
  --color-flag-navy: #1B2F6E;
  --color-flag-green: #1E8A4C;
  --font-display: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Menlo, Consolas, 'Liberation Mono', monospace;
  --radius-small: 8px;
  --radius-medium: 10px;
  --radius-pill: 999px;
  --shadow-panel: 0 16px 40px rgba(31, 58, 105, .12);
  --shadow-soft: 0 2px 8px rgba(31, 58, 105, .06);
  --shadow-window: 0 30px 70px var(--color-window-shadow);
  --content-width: 1200px;
  --reading-width: 760px;
  --header-height: 64px;
  --gutter: 24px;
  --section-space: 96px;
  --focus-size: 2px;
  --toc-offset: 132px;
  --transition-fast: 150ms ease;
  --transition-reveal: 650ms cubic-bezier(.2, .7, .2, 1);
}

*,
*::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;
  color: var(--color-text);
  background: var(--color-bg);
  font-family: var(--font-body);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body,
button,
input,
select,
textarea {
  font-family: var(--font-body);
}

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

img {
  height: auto;
}

svg {
  flex-shrink: 0;
}

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

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

button,
summary,
select {
  cursor: pointer;
}

button {
  border: 0;
}

ul,
ol {
  margin-top: 0;
}

p {
  margin-top: 0;
}

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

h1 {
  margin: 0;
  font-size: clamp(52px, 5.35vw, 64px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -.02em;
}

h2 {
  margin: 0 0 20px;
  font-size: clamp(32px, 4vw, 48px);
  line-height: 1.16;
  letter-spacing: -.018em;
}

h3 {
  margin: 0 0 12px;
  font-size: clamp(21px, 2.2vw, 28px);
  line-height: 1.25;
}

h4 {
  margin: 0 0 8px;
  font-size: 18px;
}

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

code {
  overflow-wrap: anywhere;
  padding: .1em .35em;
  border-radius: var(--radius-small);
  background: var(--color-panel-sunk);
  font-size: .9em;
}

pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--color-window-line);
  border-radius: var(--radius-medium);
  color: var(--color-window-text);
  background: var(--color-window);
  -webkit-overflow-scrolling: touch;
}

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

table {
  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);
  background: var(--color-panel-sunk);
  font-weight: 700;
}

:where(a, button, input, select, textarea, summary, [role="tab"]):focus-visible {
  outline: var(--focus-size) solid var(--color-accent-dark);
  outline-offset: 3px;
}

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

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

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

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

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

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

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.panel,
.card {
  min-width: 0;
  border: 1px solid var(--color-border-soft);
  border-radius: var(--radius-medium);
  background: var(--color-panel);
  box-shadow: var(--shadow-soft), inset 0 1px 0 var(--color-highlight);
}

.card {
  padding: 24px;
}

.badge,
.fact-pill,
.tag {
  display: inline-flex;
  min-height: 28px;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  padding: 4px 11px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-muted);
  background: var(--color-panel);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 18px;
  text-overflow: ellipsis;
}

.status-dot {
  width: 8px;
  height: 8px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-ring);
}

.btn {
  display: inline-flex;
  min-height: 46px;
  min-width: 44px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 26px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast), color var(--transition-fast);
}

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

.btn-primary {
  color: var(--color-text);
  background: linear-gradient(180deg, var(--color-accent-light), var(--color-accent));
  box-shadow: 0 8px 20px var(--color-accent-glow), inset 0 1px 0 var(--color-highlight);
}

.btn-primary:hover {
  box-shadow: 0 12px 26px var(--color-accent-glow), inset 0 1px 0 var(--color-highlight);
}

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

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

.btn-dark {
  color: var(--color-panel);
  background: var(--color-text);
}

.btn-dark:hover {
  background: var(--color-brand-deep);
}

.btn[aria-disabled="true"],
.btn:disabled {
  opacity: .55;
  pointer-events: none;
}

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

.site-header-inner {
  display: flex;
  height: 100%;
  align-items: center;
  gap: 26px;
}

.site-brand {
  display: inline-flex;
  min-height: 44px;
  flex-shrink: 0;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -.01em;
}

.site-brand img {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.brand-local {
  color: var(--color-muted);
  font-weight: 600;
}

.desktop-nav {
  display: flex;
  height: 100%;
  align-items: stretch;
  gap: 22px;
  margin-left: auto;
}

.desktop-nav a {
  position: relative;
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 500;
  transition: color var(--transition-fast);
}

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

.desktop-nav a[aria-current="page"] {
  font-weight: 700;
}

.desktop-nav a[aria-current="page"]::after {
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 2px;
  border-radius: 2px 2px 0 0;
  background: var(--color-text);
  content: "";
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 10px;
}

.header-login {
  display: inline-flex;
  min-height: 34px;
  align-items: center;
  justify-content: center;
  padding: 7px 16px;
  border-radius: var(--radius-pill);
  color: var(--color-panel);
  background: var(--color-text);
  font-size: 13px;
  font-weight: 700;
  transition: background var(--transition-fast);
}

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

.language-switcher {
  position: relative;
}

.language-toggle {
  display: inline-flex;
  min-width: 44px;
  min-height: 34px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-muted);
  background: var(--color-panel);
  font-size: 13px;
}

.language-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 55;
  display: none;
  width: 170px;
  padding: 7px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: var(--color-panel);
  box-shadow: var(--shadow-panel);
}

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

.language-menu a {
  display: flex;
  min-height: 40px;
  width: 100%;
  align-items: center;
  padding: 8px 10px;
  border-radius: var(--radius-small);
  color: var(--color-muted);
  font-size: 13px;
}

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

.menu-toggle {
  display: none;
  width: 44px;
  min-width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  color: var(--color-text);
  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: 54;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  padding: 10px var(--gutter) 20px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel);
  box-shadow: var(--shadow-panel);
  overscroll-behavior: contain;
}

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

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 46px;
  align-items: center;
  padding: 10px 12px;
  border-bottom: 1px solid var(--color-border-soft);
  color: var(--color-muted);
  font-weight: 600;
}

.mobile-nav a[aria-current="page"] {
  color: var(--color-text);
  box-shadow: inset 2px 0 0 var(--color-accent);
}

.mobile-language-list {
  margin-top: 10px;
}

.mobile-language-list strong {
  display: block;
  padding: 10px 12px 4px;
  color: var(--color-faint);
  font-family: var(--font-mono);
  font-size: 11px;
}

.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 45;
  display: none;
  background: var(--color-overlay);
}

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

.site-footer {
  overflow-x: clip;
  color: var(--color-window-text);
  background: var(--color-window);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1.2fr .9fr;
  gap: 48px;
  padding-top: 72px;
  padding-bottom: 52px;
}

.footer-brand {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
}

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

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

.footer-title {
  margin: 0 0 14px;
  color: var(--color-window-text);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.footer-links {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-links a {
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  color: var(--color-window-muted);
  font-size: 13px;
}

.footer-links a:hover {
  color: var(--color-window-text);
}

.footer-bottom {
  display: flex;
  min-height: 66px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid var(--color-window-line);
  color: var(--color-window-muted);
  font-size: 12px;
}

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

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

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

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

.prose {
  min-width: 0;
}

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

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

.prose a:not(.btn) {
  text-decoration: underline;
  text-decoration-color: var(--color-accent-dark);
  text-underline-offset: 3px;
}

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

.prose ol > li {
  position: relative;
  min-height: 32px;
  padding-left: 44px;
  counter-increment: prose-step;
}

.prose ol > li::before {
  position: absolute;
  top: 0;
  left: 0;
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  border-radius: 50%;
  color: var(--color-text);
  background: var(--color-accent);
  content: counter(prose-step);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
}

#server-status {
  position: relative;
  display: block;
  width: 100%;
  max-width: 100%;
  margin-bottom: 32px;
  overflow: hidden;
}

@media (max-width: 1080px) {
  .desktop-nav {
    gap: 14px;
  }

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

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

@media (max-width: 768px) {
  :root {
    --gutter: 20px;
    --section-space: 72px;
  }

  h1 {
    font-size: clamp(32px, 10vw, 40px);
    line-height: 1.12;
  }

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

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

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

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

  .footer-grid {
    gap: 36px 24px;
  }
}

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

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

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

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

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

  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
    padding-top: 20px;
    padding-bottom: 24px;
  }

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

  .absolute-decor,
  .stripe-halo {
    max-width: 100%;
  }
}

@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;
  }
}