:root {
  --color-canvas: #F6F9F9;
  --color-surface: #FFFFFF;
  --color-surface-soft: #EDF3F1;
  --color-border: #E1E8E5;
  --color-accent: #12995B;
  --color-accent-strong: #0B7245;
  --color-accent-soft: #E4F3EC;
  --color-accent-line: #BFE3D2;
  --color-ink: #1C2523;
  --color-ink-muted: #5D6C68;
  --color-success: #178A54;
  --color-warning: #C9871A;
  --color-error: #D14343;
  --color-mint-glow: #D9F0E6;
  --color-sky-glow: #DCEDF5;
  --color-code-bg: #18211F;
  --color-code-text: #EAF4F0;
  --color-code-muted: #A9BBB5;
  --color-overlay: rgba(28, 37, 35, 0.38);
  --color-shadow-soft: rgba(28, 37, 35, 0.08);
  --color-shadow-mid: rgba(28, 37, 35, 0.12);
  --color-shadow-strong: rgba(28, 37, 35, 0.18);
  --color-accent-shadow: rgba(18, 153, 91, 0.45);
  --color-white-shadow: rgba(255, 255, 255, 0.62);

  --font-display: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Courier New', monospace;

  --radius-xs: 8px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 28px;
  --radius-pill: 999px;

  --shadow-window: 0 32px 64px -24px var(--color-shadow-strong), 0 12px 28px -12px var(--color-shadow-mid);
  --shadow-card: 0 18px 36px -14px var(--color-shadow-strong), 0 4px 12px -4px var(--color-shadow-soft);
  --shadow-button: 0 8px 18px -8px var(--color-accent-shadow);
  --shadow-fab: 0 14px 30px -10px var(--color-accent-shadow);

  --page-width: 1184px;
  --header-width: 1280px;
  --reading-width: 790px;
  --header-height: 72px;
  --gutter: clamp(16px, 4vw, 48px);
  --section-space: clamp(68px, 9vw, 120px);
  --transition-fast: 150ms ease;
  --transition-medium: 420ms cubic-bezier(.2, .7, .2, 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;
  background: var(--color-canvas);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

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

button {
  border: 0;
}

a {
  color: var(--color-accent-strong);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--color-accent);
}

p,
ul,
ol,
dl,
blockquote,
pre,
table {
  margin-top: 0;
  margin-bottom: 1.25em;
}

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

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

h1 {
  margin-bottom: 22px;
  font-size: clamp(34px, 3.5vw, 48px);
  font-weight: 800;
  letter-spacing: -0.018em;
  line-height: 1.16;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 800;
  letter-spacing: -0.014em;
  line-height: 1.22;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 750;
  line-height: 1.32;
}

h4 {
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
}

.title-keep {
  white-space: nowrap;
}

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

.text-accent,
.h1-accent {
  color: var(--color-accent-strong);
}

.h1-accent {
  background: linear-gradient(100deg, var(--color-accent), var(--color-accent-strong));
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

:not(pre) > code {
  padding: 0.15em 0.38em;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  background: var(--color-surface-soft);
  color: var(--color-ink);
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

pre {
  max-width: 100%;
  padding: 20px;
  border-radius: var(--radius-md);
  background: var(--color-code-bg);
  color: var(--color-code-text);
  font-size: 14px;
  line-height: 1.65;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  -webkit-overflow-scrolling: touch;
}

pre code {
  color: inherit;
  white-space: pre;
}

hr {
  height: 1px;
  margin: 48px 0;
  border: 0;
  background: var(--color-border);
}

.wrap {
  width: 100%;
  max-width: calc(var(--page-width) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.reading-wrap {
  width: 100%;
  max-width: calc(var(--reading-width) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.section-lined {
  border-top: 1px solid var(--color-border);
}

.section-white {
  background: var(--color-surface);
  color: var(--color-ink);
}

.section-soft {
  background: var(--color-surface-soft);
  color: var(--color-ink);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  color: var(--color-accent-strong);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.eyebrow::before {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  content: "";
  flex-shrink: 0;
}

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

.panel {
  padding: clamp(22px, 4vw, 36px);
  box-shadow: var(--shadow-window);
}

.card {
  padding: 24px;
  box-shadow: var(--shadow-card);
}

.card-flat {
  box-shadow: none;
}

.tilt {
  transform: rotate(-1.5deg);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 25px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.25;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.button svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.button:hover {
  transform: translateY(-1px);
  text-decoration: none;
}

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

.button-primary:hover {
  background: var(--color-accent-strong);
  color: var(--color-surface);
}

.button-secondary {
  border-color: var(--color-border);
  background: var(--color-surface);
  color: var(--color-ink);
}

.button-secondary:hover {
  border-color: var(--color-accent-line);
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
}

.button-small {
  min-height: 40px;
  padding: 9px 17px;
  border-radius: var(--radius-sm);
  font-size: 14px;
}

.button[disabled],
.button.is-disabled {
  background: var(--color-surface-soft);
  color: var(--color-ink-muted);
  box-shadow: none;
  cursor: not-allowed;
  opacity: 0.72;
  transform: none;
}

.chip-row,
.badge-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.chip,
.badge {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  gap: 7px;
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 650;
  line-height: 1.35;
}

.chip {
  padding: 6px 13px;
  border: 1px solid var(--color-accent-line);
  background: var(--color-surface);
  color: var(--color-accent-strong);
}

.chip-dot::before {
  width: 6px;
  height: 6px;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  content: "";
  flex-shrink: 0;
}

.badge {
  padding: 5px 10px;
  border: 1px solid var(--color-border);
  background: var(--color-surface-soft);
  color: var(--color-ink);
  overflow-wrap: anywhere;
}

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

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

.prose h2 {
  margin-top: 2.2em;
  scroll-margin-top: 96px;
}

.prose h3 {
  margin-top: 1.8em;
  scroll-margin-top: 96px;
}

.prose a {
  text-decoration: underline;
}

.prose img {
  margin: 28px auto;
  border-radius: var(--radius-md);
}

.prose table,
.data-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-surface);
  color: var(--color-ink);
  font-size: 14px;
}

.prose th,
.prose td,
.data-table th,
.data-table td {
  padding: 13px 15px;
  border: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
}

.prose th,
.data-table th {
  background: var(--color-surface-soft);
  color: var(--color-ink);
  font-weight: 700;
}

.table-scroll {
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--transition-medium), transform var(--transition-medium);
}

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

.site-head {
  position: relative;
  z-index: 100;
  height: var(--header-height);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-canvas);
  color: var(--color-ink);
}

.head-shell {
  display: flex;
  width: 100%;
  max-width: min(100%, calc(var(--header-width) + var(--gutter) * 2));
  height: 100%;
  margin-inline: auto;
  padding-inline: var(--gutter);
  align-items: center;
  gap: 24px;
}

.brand {
  display: inline-flex;
  min-width: max-content;
  align-items: center;
  gap: 10px;
  color: var(--color-ink);
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 750;
  text-decoration: none;
}

.brand:hover {
  color: var(--color-ink);
}

.brand img {
  width: 30px;
  height: 30px;
  flex-shrink: 0;
}

.desktop-nav {
  margin-left: auto;
}

.desktop-nav ul,
.mobile-nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.desktop-nav ul {
  display: flex;
  align-items: center;
  gap: 5px;
}

.desktop-nav a {
  display: flex;
  min-height: 42px;
  align-items: center;
  padding: 8px 15px;
  border-radius: var(--radius-pill);
  color: var(--color-ink-muted);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
}

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

.desktop-nav a.is-active {
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
  font-weight: 700;
}

.head-tools {
  display: flex;
  align-items: center;
  gap: 8px;
}

.language-menu {
  position: relative;
}

.language-button {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  gap: 7px;
  padding: 8px 13px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  color: var(--color-ink-muted);
  font-size: 14px;
  cursor: pointer;
}

.language-button:hover {
  border-color: var(--color-accent-line);
  color: var(--color-ink);
}

.language-short {
  display: none;
}

.language-dropdown {
  position: absolute;
  top: calc(100% + 9px);
  right: 0;
  z-index: 130;
  width: 176px;
  margin: 0;
  padding: 7px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-ink);
  box-shadow: var(--shadow-card);
  list-style: none;
}

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

.language-dropdown a {
  display: flex;
  width: 100%;
  min-height: 42px;
  align-items: center;
  padding: 9px 11px;
  border-radius: var(--radius-sm);
  color: var(--color-ink);
  font-size: 14px;
  text-decoration: none;
}

.language-dropdown a:hover,
.language-dropdown a[aria-current="true"] {
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
}

.nav-toggle {
  display: none;
  width: 44px;
  min-width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-ink);
  cursor: pointer;
}

.nav-toggle-lines,
.nav-toggle-lines::before,
.nav-toggle-lines::after {
  display: block;
  width: 19px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-ink);
}

.nav-toggle-lines {
  position: relative;
}

.nav-toggle-lines::before,
.nav-toggle-lines::after {
  position: absolute;
  left: 0;
  content: "";
}

.nav-toggle-lines::before {
  top: -6px;
}

.nav-toggle-lines::after {
  top: 6px;
}

.mobile-nav {
  display: none;
}

.nav-veil {
  display: none;
}

.site-foot {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-ink);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(230px, 1.25fr) repeat(3, minmax(150px, 1fr));
  gap: clamp(28px, 5vw, 70px);
  padding-top: 64px;
  padding-bottom: 48px;
}

.footer-brand p {
  max-width: 29em;
  margin: 16px 0 0;
  color: var(--color-ink-muted);
  font-size: 14px;
}

.footer-column h2 {
  margin-bottom: 14px;
  font-size: 14px;
  font-weight: 750;
  letter-spacing: 0.04em;
}

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

.footer-links li + li {
  margin-top: 7px;
}

.footer-links a {
  color: var(--color-ink-muted);
  font-size: 14px;
  text-decoration: none;
}

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

.footer-bottom {
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-top: 1px solid var(--color-border);
  color: var(--color-ink-muted);
  font-size: 13px;
}

.footer-language-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
}

.footer-language-links a {
  color: var(--color-ink-muted);
  text-decoration: none;
}

.footer-language-links a[aria-current="true"] {
  color: var(--color-accent-strong);
  font-weight: 700;
}

@media (max-width: 980px) {
  .desktop-nav {
    display: none;
  }

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

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

  .mobile-nav {
    position: fixed;
    top: var(--header-height);
    right: 0;
    z-index: 120;
    display: block;
    width: min(390px, 100%);
    max-height: calc(100dvh - var(--header-height));
    padding: 12px var(--gutter) 22px;
    border-top: 1px solid var(--color-border);
    border-left: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-ink);
    box-shadow: var(--shadow-window);
    overflow-y: auto;
    overscroll-behavior: contain;
    transform: translateX(105%);
    visibility: hidden;
    transition: transform var(--transition-medium), visibility var(--transition-medium);
  }

  .mobile-nav.is-open {
    transform: none;
    visibility: visible;
  }

  .mobile-nav a {
    display: flex;
    width: 100%;
    min-height: 48px;
    align-items: center;
    padding: 11px 13px;
    border-radius: var(--radius-sm);
    color: var(--color-ink);
    font-weight: 650;
    text-decoration: none;
  }

  .mobile-nav a:hover,
  .mobile-nav a.is-active,
  .mobile-nav a[aria-current="true"] {
    background: var(--color-accent-soft);
    color: var(--color-accent-strong);
  }

  .mobile-nav-divider {
    height: 1px;
    margin: 10px 0;
    background: var(--color-border);
  }

  .mobile-nav-label {
    padding: 8px 13px 5px;
    color: var(--color-ink-muted);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.06em;
  }

  .nav-veil {
    position: fixed;
    inset: var(--header-height) 0 0;
    z-index: 90;
    display: block;
    background: var(--color-overlay);
  }

  .nav-veil[hidden] {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1.35fr 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  h1 {
    font-size: clamp(24px, 7.5vw, 30px);
    line-height: 1.2;
  }

  h2 {
    font-size: clamp(24px, 6.5vw, 32px);
  }

  .head-shell {
    gap: 10px;
  }

  .brand {
    font-size: 16px;
  }

  .brand img {
    width: 28px;
    height: 28px;
  }

  .language-full {
    display: none;
  }

  .language-short {
    display: inline;
  }

  .language-button {
    min-width: 44px;
    justify-content: center;
    padding-inline: 10px;
  }

  .language-dropdown {
    display: none;
  }

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

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

  .footer-bottom {
    padding-top: 18px;
    padding-bottom: 18px;
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 640px) {
  .tilt,
  [class*="tilt"] {
    transform: none;
  }

  .button-row {
    align-items: stretch;
  }

  .button-row .button {
    flex: 1 1 150px;
  }

  .panel,
  .card {
    border-radius: var(--radius-md);
  }

  .chip-row,
  .badge-row {
    flex-direction: row;
    align-items: center;
  }

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

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

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

@media (max-width: 380px) {
  .brand-name {
    max-width: 8em;
    font-size: 14px;
  }

  .language-button {
    display: none;
  }
}

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

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

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