:root {
  --bg: #F6F9F9;
  --panel: #FFFFFF;
  --soft: #EDF5F2;
  --blue: #EAF3F8;
  --border: #DCE5E1;
  --accent: #39745B;
  --accent-dark: #285340;
  --text: #25322E;
  --muted: #596860;
  --quiet: #838F89;
  --line: #A9C5B7;
  --success: #39745B;
  --warn: #786345;
  --error: #A45155;
  --clear: transparent;
  --veil: rgb(37 50 46 / 24%);
  --display: "Inter", "Noto Sans SC", "Noto Sans JP", "Noto Sans KR", "PingFang TC", "Microsoft JhengHei", sans-serif;
  --body: "Inter", "Noto Sans SC", "Noto Sans JP", "Noto Sans KR", "PingFang TC", "Microsoft JhengHei", sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
  --fs-xs: 11px;
  --fs-small: 12px;
  --fs-note: 13px;
  --fs-nav: 14px;
  --fs-body: 16px;
  --fs-lead: 18px;
  --fs-brand: 19px;
  --fs-title: 20px;
  --fs-h3: 22px;
  --fs-h2: clamp(24px, 2.4vw, 32px);
  --fs-display: clamp(34px, 3.3vw, 48px);
  --fs-display-compact: clamp(32px, 3.4vw, 42px);
  --fs-mobile: clamp(24px, 6.9vw, 30px);
  --regular: 400;
  --medium: 500;
  --semibold: 600;
  --bold: 700;
  --heavy: 750;
  --leading-body: 1.85;
  --leading-heading: 1.35;
  --tracking-heading: -0.02em;
  --r-small: 8px;
  --r-control: 12px;
  --r-medium: 16px;
  --r-card: 24px;
  --r-window: 28px;
  --r-field: 32px;
  --r-pill: 999px;
  --shadow-window: 0 28px 65px -26px rgb(37 50 46 / 20%), 0 3px 9px rgb(37 50 46 / 4%);
  --shadow-float: 0 24px 48px -20px rgb(37 50 46 / 23%), 0 4px 12px rgb(37 50 46 / 4%);
  --shadow-button: 0 8px 20px -9px rgb(40 83 64 / 35%);
  --gutter: 48px;
  --content-width: 1328px;
  --header-width: 1328px;
  --reading-width: 820px;
  --head-height: 100px;
  --section-space: 88px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --duration-fast: 160ms;
  --duration-reveal: 650ms;
  --duration-arrive: 850ms;
  --ease: cubic-bezier(.2, .65, .3, 1);
  --focus-ring: 2px solid var(--accent);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--body);
  font-size: var(--fs-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
}
[hidden] { display: none !important; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; }
a, button, summary { -webkit-tap-highlight-color: var(--clear); }
:where(a, button, summary, input, select, textarea, [tabindex]):focus-visible {
  outline: var(--focus-ring);
  outline-offset: 5px;
}
img, svg { display: block; max-width: 100%; }
img { height: auto; }
svg { flex-shrink: 0; }
p { margin: 0 0 1.2em; }
h1, h2, h3, h4 {
  font-family: var(--display);
  font-weight: var(--bold);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { margin: 0; font-size: var(--fs-display); font-weight: var(--heavy); }
h2 { margin: 0 0 24px; font-size: var(--fs-h2); }
h3 { margin: 0 0 16px; font-size: var(--fs-h3); }
h4 { font-size: var(--fs-title); }
strong { font-weight: var(--semibold); }
small { font-size: var(--fs-small); }
figure { margin: 0; }
ul, ol { padding-inline-start: 1.5em; }
li + li { margin-top: 8px; }
hr { border: 0; border-top: 1px solid var(--border); margin-block: 32px; }
code, kbd, pre { font-family: var(--mono); font-size: var(--fs-nav); }
code { overflow-wrap: anywhere; }
:not(pre) > code {
  background: var(--soft);
  color: var(--accent-dark);
  padding: 2px 5px;
  border-radius: var(--r-small);
}
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 24px;
  background: var(--soft);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--r-medium);
  line-height: 1.8;
  tab-size: 2;
}
pre code { white-space: pre; overflow-wrap: normal; }
:where(main, section, article, aside, nav, div, figure) { min-width: 0; }
.wrap {
  width: 100%;
  max-width: calc(var(--content-width) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: calc(var(--reading-width) + var(--gutter) * 2); }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.section-white { background: var(--panel); color: var(--text); }
.section-soft { background: var(--soft); color: var(--text); }
.section-intro { max-width: 700px; margin-bottom: 36px; }
.section-intro p, .muted { color: var(--muted); }
.keyword { white-space: nowrap; }
.emphasis { color: var(--accent); }
.prose { overflow-wrap: anywhere; }
.prose h2 { margin-top: 2em; }
.prose h3 { margin-top: 1.5em; }
.prose a:not(.button) { color: var(--accent-dark); text-decoration: underline; text-underline-offset: 4px; }
.prose :where(h2, h3, h4, section, [id]) { scroll-margin-top: 32px; }
.prose > :first-child { margin-top: 0; }
.prose > :last-child { margin-bottom: 0; }
.icon {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.65;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
}
.symbols { position: absolute; width: 0; height: 0; overflow: hidden; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: fixed;
  top: 12px;
  left: 16px;
  z-index: 100;
  transform: translateY(-160%);
  padding: 10px 16px;
  background: var(--panel);
  color: var(--accent-dark);
  border-radius: var(--r-control);
}
.skip-link:focus { transform: none; }
.actions { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
.button {
  min-height: 56px;
  padding: 12px 24px;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
  border-radius: var(--r-control);
  font-size: var(--fs-body);
  font-weight: var(--semibold);
  line-height: 1.5;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  text-align: center;
  transition: background var(--duration-fast), border-color var(--duration-fast), color var(--duration-fast);
}
.button.primary {
  background: var(--accent);
  color: var(--panel);
  border-color: var(--accent);
  box-shadow: var(--shadow-button);
}
.button.primary:hover, .button.primary.is-hover {
  background: var(--accent-dark);
  color: var(--panel);
  border-color: var(--accent-dark);
}
.button.secondary:hover, .button.secondary.is-hover { border-color: var(--accent); color: var(--accent-dark); }
.button:active, .button.is-active { box-shadow: none; transform: translateY(1px); }
.button.is-focus { outline: var(--focus-ring); outline-offset: 5px; }
.button:disabled, .button[aria-disabled="true"] {
  background: var(--soft);
  color: var(--muted);
  border-color: var(--border);
  box-shadow: none;
  transform: none;
}
.button .icon { width: 20px; height: 20px; }
.text-link { color: var(--accent-dark); text-decoration: underline; text-underline-offset: 5px; }
.card, .panel {
  padding: var(--space-4);
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--r-card);
}
.panel { border-radius: var(--r-window); box-shadow: var(--shadow-window); }
.card > :last-child, .panel > :last-child { margin-bottom: 0; }
.card-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.decorated-section { overflow-x: clip; }
.tilt-decoration { transform: rotate(-3deg); }
.reveal { opacity: 1; transform: none; }
.reveal.is-observed {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity var(--duration-reveal) var(--ease), transform var(--duration-reveal) var(--ease);
}
.reveal.shown { opacity: 1; transform: none; }

#site-header, .preview-header { position: relative; z-index: 60; }
.site-head {
  width: 100%;
  max-width: min(100%, calc(var(--header-width) + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
  height: var(--head-height);
  display: flex;
  align-items: center;
  gap: 28px;
  position: relative;
}
.site-head::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: var(--gutter);
  right: var(--gutter);
  height: 1px;
  background: var(--border);
  color: var(--text);
}
.brand { display: flex; align-items: center; gap: 12px; white-space: nowrap; font-weight: var(--bold); font-size: var(--fs-brand); line-height: 1.3; }
.brand-mark { width: 40px; height: 40px; flex-shrink: 0; }
.main-nav { display: flex; align-items: center; gap: 7px; margin-left: auto; }
.main-nav a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 11px 9px;
  border-radius: var(--r-control);
  white-space: nowrap;
  font-size: var(--fs-nav);
  font-weight: var(--medium);
  line-height: 1.5;
  color: var(--muted);
}
.main-nav a[aria-current="page"] { background: var(--soft); color: var(--accent-dark); }
.main-nav a:hover { background: var(--soft); color: var(--accent-dark); }
.main-nav .icon { width: 16px; height: 16px; }
.header-tools { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.language-picker { position: relative; }
.language {
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  font-size: var(--fs-note);
  line-height: 1.5;
  color: var(--muted);
  background: var(--clear);
  padding: 10px 0 10px 20px;
  border: 0;
  border-left: 1px solid var(--border);
  min-height: 44px;
}
.language-short { display: none; }
.language-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 12px);
  width: 190px;
  padding: 8px;
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--r-medium);
  box-shadow: var(--shadow-float);
}
.language-menu a { display: flex; align-items: center; width: 100%; min-height: 44px; padding: 8px 12px; border-radius: var(--r-small); }
.language-menu a:hover, .language-menu a[aria-current="true"] { background: var(--soft); color: var(--accent-dark); }
.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: var(--r-control);
  background: var(--panel);
  color: var(--text);
}
.mobile-drawer { display: none; }
.nav-veil {
  position: fixed;
  inset: var(--head-height) 0 0;
  z-index: -1;
  border: 0;
  background: var(--veil);
  color: var(--text);
  width: 100%;
  cursor: default;
}
.preview-mobile { display: none; }

.site-footer {
  margin-top: 0;
  padding-top: 64px;
  padding-bottom: 100px;
  border-top: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
}
.footer-grid { display: grid; grid-template-columns: 1.2fr 1fr 1.3fr .75fr; gap: 40px; }
.footer-brand p { max-width: 310px; margin-top: 20px; color: var(--muted); font-size: var(--fs-nav); }
.footer-heading { margin: 0 0 16px; font-size: var(--fs-nav); font-weight: var(--semibold); }
.footer-links { display: grid; align-content: start; gap: 8px; }
.footer-links a { color: var(--muted); font-size: var(--fs-nav); overflow-wrap: anywhere; }
.footer-links a:hover { color: var(--accent-dark); text-decoration: underline; text-underline-offset: 4px; }
.footer-bottom {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--muted);
  font-size: var(--fs-note);
}
.legal-links { display: flex; gap: 24px; flex-wrap: wrap; }

@media (max-width: 1250px) {
  :root { --gutter: 28px; }
  .site-head { gap: 18px; }
  .brand { font-size: var(--fs-body); }
  .main-nav { gap: 0; }
  .main-nav a { padding: 10px 7px; font-size: var(--fs-note); }
  .language { padding-left: 14px; }
  h1 { font-size: var(--fs-display-compact); }
}
@media (max-width: 1120px) {
  :root { --head-height: 88px; }
  .site-head { background: var(--bg); color: var(--text); }
  .main-nav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: flex; }
  .mobile-drawer {
    display: block;
    position: absolute;
    z-index: 2;
    top: var(--head-height);
    left: 0;
    right: 0;
    max-height: calc(100vh - var(--head-height));
    max-height: calc(100dvh - var(--head-height));
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: 16px var(--gutter) 28px;
    background: var(--panel);
    color: var(--text);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-window);
  }
  .mobile-drawer a {
    display: flex;
    align-items: center;
    width: 100%;
    gap: 12px;
    min-height: 48px;
    padding: 12px 16px;
    border-radius: var(--r-control);
    font-size: var(--fs-nav);
  }
  .mobile-drawer a:hover, .mobile-drawer a[aria-current] { background: var(--soft); color: var(--accent-dark); }
  .drawer-label { margin: 20px 16px 8px; color: var(--muted); font-size: var(--fs-small); }
  .preview-mobile { display: block; }
  .preview-mobile > summary { list-style: none; }
  .preview-mobile > summary::-webkit-details-marker { display: none; }
  .preview-mobile:not([open]) .mobile-drawer { display: none; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 768px) {
  h1 { font-size: var(--fs-mobile); line-height: 1.4; }
  :root { --section-space: 56px; }
}
@media (max-width: 640px) {
  :root { --gutter: 18px; --space-4: 24px; --head-height: 78px; }
  .keyword { white-space: normal; }
  .wrap, .site-head { padding-inline: var(--gutter); }
  .brand { font-size: var(--fs-nav); gap: 8px; }
  .brand-mark { width: 34px; height: 34px; }
  .site-head { gap: 8px; }
  .header-tools { gap: 6px; margin-left: auto; }
  .language { border: 0; padding-left: 0; font-size: var(--fs-small); }
  .language > .icon, .language-full { display: none; }
  .language-short { display: inline; }
  .card-grid, .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { gap: 28px; }
  .actions { gap: 10px; }
  .button { min-height: 51px; padding-inline: 18px; font-size: var(--fs-nav); }
  .tilt, .tilt-decoration { transform: none; }
  pre { padding: 18px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal.is-observed { opacity: 1; transform: none; }
}