:root {
  --color-page: #FFFFFF;
  --color-panel: #F7F7F8;
  --color-panel-strong: #EFF0F2;
  --color-line: #E5E6E9;
  --color-accent: #DE4B63;
  --color-accent-deep: #B8354D;
  --color-ink: #2B2D33;
  --color-muted: #686B72;
  --color-success: #2F9E63;
  --color-warning: #D98A24;
  --color-error: #C43D3D;
  --color-sketch: #A8CCDD;
  --color-on-dark: #FFFFFF;
  --color-dark-muted: #C8C9CD;
  --color-dark-line: rgba(255, 255, 255, 0.11);
  --color-accent-shadow: rgba(222, 75, 99, 0.28);
  --color-shadow-soft: rgba(43, 45, 51, 0.06);
  --color-shadow-mid: rgba(43, 45, 51, 0.10);
  --color-shadow-deep: rgba(43, 45, 51, 0.14);
  --font-display: 'Inter', 'Noto Sans SC', -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, 'Courier New', monospace;
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 14px;
  --radius-sm: 9px;
  --radius-pill: 999px;
  --shadow-card: 0 1px 2px var(--color-shadow-soft), 0 12px 28px -14px var(--color-shadow-mid), 0 36px 72px -30px var(--color-shadow-deep);
  --shadow-float: 0 8px 22px var(--color-shadow-soft), 0 28px 60px -24px var(--color-shadow-deep);
  --content-width: 1120px;
  --reading-width: 800px;
  --header-width: 1280px;
  --gutter: clamp(16px, 4vw, 32px);
  --header-height: 64px;
  --section-space: clamp(88px, 12vw, 152px);
  --ease-standard: 180ms ease;
}

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

html {
  background: var(--color-page);
  color: var(--color-ink);
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  margin: 0;
  overflow-x: clip;
  background: var(--color-page);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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 {
  border: 0;
}

a {
  color: var(--color-accent-deep);
  text-decoration-thickness: 0.08em;
  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: 1.4em;
}

h1,
h2,
h3,
h4 {
  margin-top: 0;
  color: var(--color-ink);
  font-family: var(--font-display);
  line-height: 1.18;
  text-wrap: balance;
}

h1 {
  margin-bottom: 22px;
  font-size: clamp(34px, 3.5vw, 48px);
  font-weight: 800;
  letter-spacing: -0.012em;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 800;
  letter-spacing: -0.01em;
}

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

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

strong {
  color: var(--color-ink);
  font-weight: 700;
}

small {
  font-size: 0.82em;
}

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

:not(pre) > code {
  padding: 0.14em 0.38em;
  border-radius: var(--radius-sm);
  background: var(--color-panel-strong);
  color: var(--color-ink);
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

pre {
  max-width: 100%;
  padding: 20px;
  overflow-x: auto;
  border-radius: var(--radius-md);
  background: var(--color-ink);
  color: var(--color-on-dark);
  font: 13px/1.75 var(--font-mono);
  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-line);
}

::selection {
  background: var(--color-accent);
  color: var(--color-on-dark);
}

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
}

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

.wrap {
  max-width: calc(var(--content-width) + var(--gutter) * 2);
}

.reading-wrap {
  max-width: calc(var(--reading-width) + var(--gutter) * 2);
}

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

.section-heading {
  max-width: 780px;
  margin-inline: auto;
  text-align: center;
}

.section-heading p {
  color: var(--color-muted);
  font-size: clamp(16px, 1.6vw, 19px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 15px;
  color: var(--color-muted);
  font: 600 12px/1.4 var(--font-mono);
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

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

.nowrap-term {
  white-space: nowrap;
}

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

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

.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 13px;
}

.button-row.center {
  justify-content: center;
}

.button {
  min-height: 46px;
  padding: 11px 25px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  color: var(--color-ink);
  background: var(--color-page);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.25;
  text-align: center;
  text-decoration: none;
  transition: transform var(--ease-standard), background-color var(--ease-standard), box-shadow var(--ease-standard);
}

.button svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.button:hover {
  color: var(--color-ink);
  transform: translateY(-1px);
}

.button-primary {
  background: var(--color-accent);
  color: var(--color-on-dark);
  box-shadow: 0 9px 20px -9px var(--color-accent-shadow);
}

.button-primary:hover {
  background: var(--color-accent-deep);
  color: var(--color-on-dark);
}

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

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

.button-quiet {
  background: var(--color-panel);
  color: var(--color-ink);
}

.button[aria-disabled="true"],
.button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  transform: none;
}

.card,
.panel {
  border-radius: var(--radius-lg);
  background: var(--color-page);
  color: var(--color-ink);
}

.card {
  padding: clamp(22px, 3vw, 34px);
  box-shadow: var(--shadow-card);
}

.panel {
  padding: clamp(20px, 3vw, 30px);
  background: var(--color-panel);
  color: var(--color-ink);
}

.grid-2,
.grid-3,
.grid-4 {
  display: grid;
  gap: 24px;
}

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

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 650ms ease, transform 650ms ease;
}

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

.tilt-left {
  transform: rotate(-0.35deg);
}

.tilt-right {
  transform: rotate(0.35deg);
}

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

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

.prose h2 {
  margin-top: 2.3em;
}

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

.prose a {
  overflow-wrap: anywhere;
}

.prose table,
.data-table {
  width: 100%;
  border-collapse: collapse;
  color: var(--color-ink);
}

.prose th,
.prose td,
.data-table th,
.data-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--color-line);
  text-align: left;
  vertical-align: top;
}

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

.table-scroll {
  max-width: 100%;
  overflow-x: auto;
  border-radius: var(--radius-md);
  -webkit-overflow-scrolling: touch;
}

.table-scroll table {
  min-width: 680px;
}

.site-header {
  position: relative;
  z-index: 100;
  height: var(--header-height);
  background: var(--color-page);
  color: var(--color-ink);
}

.site-header__inner {
  width: 100%;
  max-width: min(100%, calc(var(--header-width) + var(--gutter) * 2));
  height: var(--header-height);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: 18px;
}

.site-brand {
  display: inline-flex;
  flex-shrink: 0;
  align-items: center;
  gap: 10px;
  color: var(--color-ink);
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 750;
  text-decoration: none;
}

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

.site-brand img {
  width: 29px;
  height: 29px;
  flex-shrink: 0;
}

.desktop-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 3px;
}

.desktop-nav > a,
.nav-more__button {
  min-height: 40px;
  padding: 8px 13px;
  border-radius: var(--radius-pill);
  display: inline-flex;
  align-items: center;
  color: var(--color-ink);
  background: var(--color-page);
  font-size: 14px;
  font-weight: 550;
  text-decoration: none;
  white-space: nowrap;
}

.desktop-nav > a:hover,
.desktop-nav > a.is-active,
.nav-more__button:hover,
.nav-more.is-active .nav-more__button {
  background: var(--color-panel);
  color: var(--color-ink);
}

.nav-more {
  position: relative;
}

.nav-more__button {
  cursor: pointer;
  gap: 6px;
}

.nav-caret {
  color: var(--color-muted);
  font-size: 10px;
}

.nav-more__menu,
.language-menu {
  position: absolute;
  top: calc(100% + 7px);
  right: 0;
  min-width: 174px;
  padding: 7px;
  visibility: hidden;
  border-radius: var(--radius-md);
  background: var(--color-page);
  color: var(--color-ink);
  box-shadow: var(--shadow-float);
  opacity: 0;
  transform: translateY(-5px);
  transition: opacity var(--ease-standard), transform var(--ease-standard), visibility var(--ease-standard);
}

.nav-more:hover .nav-more__menu,
.nav-more:focus-within .nav-more__menu,
.nav-more.is-open .nav-more__menu,
.language-picker.is-open .language-menu {
  visibility: visible;
  opacity: 1;
  transform: none;
}

.nav-more__menu a,
.language-menu a {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  color: var(--color-ink);
  font-size: 14px;
  font-weight: 550;
  text-decoration: none;
}

.nav-more__menu a:hover,
.nav-more__menu a.is-active,
.language-menu a:hover,
.language-menu a[aria-current="true"] {
  background: var(--color-panel);
  color: var(--color-ink);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 5px;
}

.language-picker {
  position: relative;
}

.language-button {
  min-height: 36px;
  padding: 7px 13px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-page);
  color: var(--color-ink);
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
}

.language-short {
  display: none;
}

.menu-toggle {
  width: 44px;
  min-width: 44px;
  height: 44px;
  min-height: 44px;
  padding: 10px;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border-radius: var(--radius-pill);
  background: var(--color-page);
  color: var(--color-ink);
  cursor: pointer;
}

.menu-toggle span {
  width: 19px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-ink);
}

.mobile-nav {
  display: none;
}

.mobile-nav__section {
  padding: 8px 0;
}

.mobile-nav__label {
  padding: 8px 16px;
  color: var(--color-muted);
  font: 600 11px/1.4 var(--font-mono);
  letter-spacing: 0.13em;
}

.mobile-nav a {
  width: 100%;
  min-height: 48px;
  padding: 11px 16px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  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-panel);
  color: var(--color-ink);
}

.nav-veil {
  display: none;
}

.site-footer {
  margin-top: var(--section-space);
  padding-top: 72px;
  padding-bottom: 26px;
  background: var(--color-panel);
  color: var(--color-ink);
}

.site-footer__inner {
  max-width: calc(var(--header-width) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: minmax(240px, 1.35fr) repeat(3, minmax(150px, 1fr));
  gap: 48px;
}

.footer-brand {
  max-width: 360px;
}

.footer-brand .site-brand {
  margin-bottom: 16px;
}

.footer-brand p {
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.8;
}

.footer-title {
  margin-bottom: 15px;
  color: var(--color-ink);
  font: 700 13px/1.4 var(--font-display);
}

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

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

.footer-links a {
  display: inline-flex;
  padding: 3px 0;
  color: var(--color-muted);
  font-size: 14px;
  text-decoration: none;
}

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

.footer-bottom {
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--color-line);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 24px;
  color: var(--color-muted);
  font-size: 13px;
}

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

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

@media (max-width: 960px) {
  .desktop-nav {
    display: none;
  }

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

  .menu-toggle {
    display: flex;
  }

  .language-picker .language-menu {
    display: none;
  }

  .mobile-nav {
    position: fixed;
    z-index: 103;
    top: var(--header-height);
    right: var(--gutter);
    left: var(--gutter);
    max-height: calc(100dvh - var(--header-height) - 12px);
    padding: 10px;
    overflow-y: auto;
    overscroll-behavior: contain;
    border-radius: var(--radius-lg);
    background: var(--color-page);
    color: var(--color-ink);
    box-shadow: var(--shadow-float);
  }

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

  .nav-veil {
    position: fixed;
    z-index: 99;
    inset: var(--header-height) 0 0;
    background: var(--color-shadow-mid);
  }

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

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

@media (max-width: 768px) {
  h1 {
    font-size: clamp(24px, 7.5vw, 30px);
    line-height: 1.22;
    letter-spacing: -0.01em;
  }

  h2 {
    font-size: clamp(24px, 7vw, 32px);
  }

  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .section {
    padding-top: 84px;
    padding-bottom: 84px;
  }
}

@media (max-width: 640px) {
  .site-header__inner {
    gap: 8px;
  }

  .site-brand__name {
    font-size: 14px;
  }

  .language-full {
    display: none;
  }

  .language-short {
    display: inline;
  }

  .language-button {
    min-width: 44px;
    min-height: 44px;
    padding-inline: 10px;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: minmax(0, 1fr);
  }

  .button-row {
    justify-content: center;
  }

  .button-row .button {
    max-width: 100%;
  }

  .tilt-left,
  .tilt-right {
    transform: none;
  }

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

  .site-footer__grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 34px;
  }

  .footer-bottom {
    flex-direction: column;
  }
}

@media (max-width: 400px) {
  .site-brand__name {
    max-width: 128px;
    line-height: 1.25;
  }

  .button {
    width: 100%;
  }
}

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

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

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