:root {
  --color-page: #FFFFFF;
  --color-panel: #F7F8F9;
  --color-panel-strong: #EFF1F3;
  --color-line: #E3E6EA;
  --color-accent: #ED7B2F;
  --color-accent-dark: #C85E1A;
  --color-accent-soft: #FCEDE1;
  --color-ink: #22272D;
  --color-muted: #6B7480;
  --color-success: #3E9B63;
  --color-warning: #D99A2B;
  --color-error: #D14B41;
  --color-sky: #BCDCEA;
  --color-sky-deep: #8FBDD4;
  --color-apricot: #F5CDB6;
  --color-apricot-deep: #E5A382;
  --color-yellow: #F2E2AC;
  --color-cream: #FAF3E5;
  --color-flag-red: #C8382F;
  --color-flag-blue: #2E4390;
  --color-overlay: rgb(34 39 45 / 46%);
  --color-shadow: rgb(34 39 45 / 8%);
  --font-display: Georgia, 'Iowan Old Style', 'Times New Roman', 'Songti SC', 'Noto Serif CJK SC', 'SimSun', serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Courier New', monospace;
  --radius-xs: 5px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-pill: 999px;
  --page-max: 1352px;
  --reading-max: 57rem;
  --gutter: clamp(16px, 4vw, 48px);
  --header-height: 68px;
  --toc-top: 76px;
  --space-section: clamp(64px, 9vw, 120px);
  --ease-standard: cubic-bezier(.2, .75, .25, 1);
  --shadow-low: 0 10px 28px var(--color-shadow);
}

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

html {
  min-width: 320px;
  scroll-behavior: smooth;
  background: var(--color-page);
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  overflow-x: clip;
  background: var(--color-page);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

main,
section,
article,
aside,
header,
footer,
nav,
div {
  min-width: 0;
}

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

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

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
}

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

a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: var(--radius-xs);
}

p,
h1,
h2,
h3,
h4,
ul,
ol,
dl,
dd,
figure,
blockquote,
pre {
  margin-top: 0;
}

ul,
ol {
  padding-left: 1.3em;
}

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

code {
  overflow-wrap: anywhere;
}

pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 1.25rem;
  border-radius: var(--radius-sm);
  background: var(--color-ink);
  color: var(--color-page);
  line-height: 1.65;
  -webkit-overflow-scrolling: touch;
}

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

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

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

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

.reading-wrap {
  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);
}

.section-tight {
  padding-top: clamp(36px, 6vw, 72px);
  padding-bottom: clamp(36px, 6vw, 72px);
}

h1,
h2,
h3,
.display-title {
  color: var(--color-ink);
  font-family: var(--font-display);
  font-weight: 700;
  text-wrap: balance;
}

h1,
.hero-title {
  max-width: 100%;
  margin-bottom: 1.25rem;
  font-size: clamp(52px, 5.1vw, 72px);
  line-height: 1.1;
  letter-spacing: -.012em;
}

h2 {
  margin-bottom: 1rem;
  font-size: clamp(34px, 4vw, 52px);
  line-height: 1.16;
  letter-spacing: -.01em;
}

h3 {
  margin-bottom: .75rem;
  font-size: clamp(23px, 2.5vw, 31px);
  line-height: 1.25;
}

h4 {
  margin-bottom: .55rem;
  font-size: 1.08rem;
}

p {
  margin-bottom: 1.15rem;
}

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

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

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

.mono-note {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .06em;
  color: var(--color-muted);
}

.eyebrow,
.badge,
.tag {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  gap: .5rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .06em;
  line-height: 1.4;
  overflow-wrap: anywhere;
}

.eyebrow {
  padding: .32rem .85rem;
}

.badge,
.tag {
  padding: .28rem .68rem;
}

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

.badge-success {
  border-color: var(--color-success);
  color: var(--color-success);
}

.badge-warning {
  border-color: var(--color-warning);
  color: var(--color-warning);
}

.btn,
.btn-primary,
.btn-secondary,
.btn-quiet {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: .55rem;
  padding: .75rem 1.65rem;
  border: 1.5px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-weight: 650;
  line-height: 1.25;
  text-align: center;
  transition:
    background-color .16s ease,
    border-color .16s ease,
    color .16s ease,
    transform .16s ease;
}

.btn:hover,
.btn-primary:hover,
.btn-secondary:hover,
.btn-quiet:hover {
  transform: translateY(-1px);
}

.btn-primary {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: var(--color-page);
}

.btn-primary:hover {
  border-color: var(--color-accent-dark);
  background: var(--color-accent-dark);
}

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

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

.btn-quiet {
  border-color: transparent;
  background: var(--color-panel);
  color: var(--color-ink);
}

.btn[disabled],
.btn-primary[disabled],
.btn-secondary[disabled] {
  cursor: not-allowed;
  opacity: .55;
  transform: none;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .85rem;
}

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

.panel {
  padding: clamp(20px, 4vw, 40px);
}

.card {
  padding: clamp(18px, 3vw, 28px);
}

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

.card:hover {
  border-color: var(--color-apricot-deep);
}

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

.header-inner {
  position: relative;
  display: flex;
  width: 100%;
  max-width: var(--page-max);
  min-height: var(--header-height);
  align-items: center;
  gap: 1.5rem;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: .58rem;
}

.site-brand img {
  width: 32px;
  height: 32px;
  flex: 0 0 auto;
}

.brand-copy {
  display: inline-flex;
  align-items: baseline;
  gap: .42rem;
  white-space: nowrap;
}

.brand-word {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1;
}

.brand-local {
  color: var(--color-muted);
  font-size: .74rem;
  font-weight: 500;
  letter-spacing: .05em;
}

.desktop-nav {
  display: flex;
  min-width: 0;
  flex: 1 1 auto;
  align-items: center;
  gap: 2px;
}

.desktop-nav a {
  border-radius: var(--radius-pill);
  color: var(--color-muted);
  font-size: .875rem;
  padding: .42rem .78rem;
  white-space: nowrap;
}

.desktop-nav a:hover {
  background: var(--color-panel);
  color: var(--color-ink);
}

.desktop-nav a[aria-current="page"] {
  background: var(--color-accent-soft);
  color: var(--color-accent-dark);
  font-weight: 650;
}

.header-tools {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: .65rem;
}

.language {
  position: relative;
}

.language-toggle {
  min-height: 40px;
  padding: .35rem .55rem;
  border: 0;
  background: transparent;
  color: var(--color-muted);
  cursor: pointer;
  font-size: .84rem;
  white-space: nowrap;
}

.language-menu {
  position: absolute;
  top: calc(100% + .55rem);
  right: 0;
  z-index: 90;
  display: none;
  width: 160px;
  padding: .4rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-page);
  box-shadow: var(--shadow-low);
}

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

.language-menu a {
  display: block;
  min-height: 42px;
  padding: .55rem .7rem;
  border-radius: var(--radius-xs);
  color: var(--color-muted);
}

.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: .48rem 1.15rem;
  border-radius: var(--radius-sm);
  background: var(--color-accent);
  color: var(--color-page);
  font-size: .875rem;
  font-weight: 650;
  white-space: nowrap;
}

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

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

.menu-toggle svg {
  width: 22px;
  height: 22px;
}

.mobile-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 70;
  display: none;
  background: var(--color-overlay);
}

.mobile-drawer {
  position: absolute;
  top: 100%;
  right: 0;
  left: 0;
  z-index: 85;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: .75rem var(--gutter) 1.25rem;
  border-bottom: 1px solid var(--color-line);
  background: var(--color-page);
  -webkit-overflow-scrolling: touch;
}

.mobile-drawer a {
  display: flex;
  width: 100%;
  min-height: 46px;
  align-items: center;
  padding: .65rem .8rem;
  border-radius: var(--radius-sm);
  color: var(--color-muted);
}

.mobile-drawer a:hover,
.mobile-drawer a[aria-current="page"] {
  background: var(--color-accent-soft);
  color: var(--color-accent-dark);
}

.mobile-language {
  margin-top: .6rem;
  padding-top: .6rem;
  border-top: 1px solid var(--color-line);
}

.site-header.menu-open .mobile-drawer,
.site-header.menu-open + .mobile-veil {
  display: block;
}

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

.footer-main {
  display: grid;
  grid-template-columns: minmax(220px, 1.2fr) repeat(3, minmax(150px, .8fr));
  gap: clamp(28px, 5vw, 64px);
  padding-top: 56px;
  padding-bottom: 44px;
}

.footer-brand {
  max-width: 22rem;
}

.footer-brand .site-brand {
  margin-bottom: 1rem;
}

.footer-brand p {
  color: var(--color-muted);
  font-size: .92rem;
}

.footer-column h2 {
  margin-bottom: .8rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .1em;
  text-transform: uppercase;
}

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

.footer-links a {
  display: inline-block;
  padding: .22rem 0;
  color: var(--color-muted);
  font-size: .9rem;
}

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

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .75rem 1.5rem;
  padding-top: 18px;
  padding-bottom: 24px;
  border-top: 1px solid var(--color-line);
  color: var(--color-muted);
  font-size: .82rem;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem 1rem;
}

.reveal {
  transition:
    opacity .55s var(--ease-standard),
    transform .55s var(--ease-standard);
}

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

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

.decorative-region,
.hero-stage,
.hero-visual {
  overflow-x: clip;
}

.tilt {
  transform: rotate(-.45deg);
}

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

.prose > * {
  max-width: 100%;
}

.prose h2,
.prose h3 {
  scroll-margin-top: calc(var(--toc-top) + 16px);
}

.prose a {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: .18em;
}

.prose blockquote {
  margin-inline: 0;
}

body:has(.toc-tabs) section[id] {
  scroll-margin-top: calc(var(--toc-top) + 26px);
}

@media (max-width: 1180px) {
  .desktop-nav {
    display: none;
  }

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

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

@media (max-width: 768px) {
  :root {
    --header-height: 62px;
    --toc-top: 70px;
  }

  h1,
  .hero-title {
    font-size: clamp(32px, 9.4vw, 40px);
    line-height: 1.12;
    letter-spacing: -.01em;
  }

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

  .header-inner {
    gap: .6rem;
  }

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

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

  .header-login {
    min-height: 40px;
    padding-inline: .85rem;
  }

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

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

  .decorative-label {
    display: none;
  }
}

@media (max-width: 640px) {
  .wrap,
  .reading-wrap {
    padding-inline: max(16px, var(--gutter));
  }

  .button-row > .btn,
  .button-row > .btn-primary,
  .button-row > .btn-secondary {
    flex: 1 1 140px;
  }

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

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

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

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

  table {
    max-width: 100%;
  }
}

@media (max-width: 390px) {
  .brand-word {
    font-size: 1.08rem;
  }

  .header-login {
    padding-inline: .68rem;
  }

  .header-tools {
    gap: .4rem;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

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