:root {
  --color-bg: #FBFBFB;
  --color-panel: #FFFFFF;
  --color-panel-alt: #EDF6F2;
  --color-border: #E4E8EC;
  --color-border-strong: #C9D2DA;
  --color-accent: #2B8FE8;
  --color-accent-dark: #1B6FC2;
  --color-accent-soft: #E6F2FD;
  --color-text: #21262C;
  --color-text-muted: #68717C;
  --color-success: #19A05B;
  --color-warning: #F5B93E;
  --color-warning-soft: #FCEFD2;
  --color-warning-text: #79520B;
  --color-error: #E0524A;
  --color-violet: #8E7CF0;
  --color-orange: #F08C3A;
  --color-white: #FFFFFF;
  --color-code-bg: #F3F6F8;
  --color-footer-bg: #EDF6F2;

  --sky-deep: #2A7CDC;
  --sky-top: #3D9BF0;
  --sky-mid: #5FAEF2;
  --sky-low: #A8D4F5;
  --sky-warm: #F6E3B4;
  --sky-soft-text: #D9ECFD;
  --city-far: #CFE5F7;
  --city-far-alt: #DCEDFA;
  --city-mid: #8FB6DE;
  --city-mid-dark: #7BA5D2;
  --city-near: #6E97C6;
  --city-near-dark: #5C86B7;
  --city-light: #F2E2BC;
  --city-window: #EAF4FC;
  --city-window-warm: #F7DFA0;
  --leaf-one: #7FBF8E;
  --leaf-two: #9BCFA7;
  --leaf-three: #62A877;

  --flag-red: #D7423C;
  --flag-blue: #2A5DB0;
  --flag-navy: #31519C;
  --flag-white: #FFFFFF;
  --flag-black: #21262C;

  --glass-nav: rgba(255, 255, 255, 0.70);
  --glass-border: rgba(255, 255, 255, 0.80);
  --glass-chip: rgba(255, 255, 255, 0.15);
  --glass-chip-border: rgba(255, 255, 255, 0.38);
  --glass-hover: rgba(255, 255, 255, 0.26);
  --white-98: rgba(255, 255, 255, 0.98);
  --white-95: rgba(255, 255, 255, 0.95);
  --white-80: rgba(255, 255, 255, 0.80);
  --white-60: rgba(255, 255, 255, 0.60);
  --white-45: rgba(255, 255, 255, 0.45);
  --white-zero: rgba(255, 255, 255, 0);
  --blue-veil: rgba(23, 84, 158, 0.34);
  --blue-zero: rgba(23, 84, 158, 0);
  --sun-glow: rgba(255, 232, 178, 0.55);
  --sun-zero: rgba(255, 232, 178, 0);
  --cloud-warm: rgba(255, 226, 168, 0.38);
  --overlay: rgba(33, 38, 44, 0.32);

  --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, monospace;

  --radius-xs: 8px;
  --radius-sm: 10px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 22px;
  --radius-section: 30px;
  --radius-pill: 999px;

  --shadow-nav: 0 8px 28px rgba(20, 70, 130, 0.14);
  --shadow-card: 0 24px 62px rgba(24, 60, 100, 0.12);
  --shadow-soft: 0 16px 42px rgba(24, 60, 100, 0.09);
  --shadow-device: 0 46px 110px rgba(13, 60, 116, 0.38), 0 16px 34px rgba(13, 60, 116, 0.20), inset 0 1px 0 var(--white-98);
  --shadow-button: 0 12px 28px rgba(16, 72, 134, 0.28);
  --shadow-focus: 0 0 0 4px rgba(43, 143, 232, 0.18);

  --content-width: 1120px;
  --header-width: 1280px;
  --reading-width: 780px;
  --gutter: clamp(16px, 4vw, 32px);
  --section-space: clamp(64px, 9vw, 112px);
  --transition-fast: 160ms ease;
  --transition-slow: 520ms cubic-bezier(0.2, 0.7, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  background: var(--color-bg);
}

html.nav-open {
  overflow: hidden;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: clip;
  background: var(--color-bg);
  color: var(--color-text);
  font: 400 16px/1.72 var(--font-body);
  text-rendering: optimizeLegibility;
}

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-dark);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

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

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

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

h1,
h2,
h3,
h4 {
  color: var(--color-text);
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.18;
  text-wrap: balance;
}

h1 {
  margin-bottom: 20px;
  font-size: clamp(34px, 4.5vw, 48px);
  letter-spacing: -0.018em;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(28px, 3vw, 38px);
  letter-spacing: -0.012em;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(20px, 2vw, 25px);
}

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

p {
  margin-bottom: 1.15em;
}

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

li + li {
  margin-top: 0.38em;
}

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

:not(pre) > code {
  padding: 0.12em 0.4em;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  background: var(--color-code-bg);
  color: var(--color-text);
  font-size: 0.9em;
}

pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-code-bg);
  color: var(--color-text);
  font: 500 13px/1.7 var(--font-mono);
  -webkit-overflow-scrolling: touch;
}

table {
  border-collapse: collapse;
}

th,
td {
  overflow-wrap: anywhere;
}

hr {
  height: 1px;
  margin: 40px 0;
  border: 0;
  background: var(--color-border);
}

.wrap {
  width: 100%;
  max-width: calc(var(--content-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);
}

.header-shell {
  width: 100%;
  max-width: min(100%, calc(var(--header-width) + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.section-tight {
  padding-top: clamp(42px, 6vw, 72px);
  padding-bottom: clamp(42px, 6vw, 72px);
  overflow-x: clip;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 38px;
}

.section-heading.centered {
  margin-inline: auto;
  text-align: center;
}

.section-heading p {
  color: var(--color-text-muted);
  font-size: 17px;
}

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

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

.eyebrow,
.badge {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  gap: 7px;
  overflow: hidden;
  padding: 6px 12px;
  border-radius: var(--radius-pill);
  background: var(--color-accent-soft);
  color: var(--color-accent-dark);
  font-size: 13px;
  font-weight: 750;
  line-height: 1.25;
}

.eyebrow-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 7px;
  border-radius: 50%;
  background: var(--color-success);
}

.badge-warning {
  background: var(--color-warning-soft);
  color: var(--color-warning-text);
}

.badge-violet {
  background: var(--color-panel-alt);
  color: var(--color-text);
  box-shadow: inset 3px 0 var(--color-violet);
}

.badge-orange {
  background: var(--color-panel-alt);
  color: var(--color-text);
  box-shadow: inset 3px 0 var(--color-orange);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  cursor: pointer;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 750;
  line-height: 1.3;
  text-decoration: none;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
}

.button svg {
  width: 17px;
  height: 17px;
  flex-shrink: 0;
}

.button-primary {
  border-color: var(--color-accent-dark);
  background: var(--color-accent-dark);
  color: var(--color-white);
  box-shadow: 0 8px 20px rgba(27, 111, 194, 0.24);
}

.button-primary:hover {
  transform: translateY(-2px);
  background: var(--color-text);
  color: var(--color-white);
}

.button-secondary {
  border-color: var(--color-border-strong);
  background: var(--color-panel);
  color: var(--color-text);
}

.button-secondary:hover {
  transform: translateY(-2px);
  border-color: var(--color-accent);
  color: var(--color-accent-dark);
  box-shadow: var(--shadow-soft);
}

.button-disabled,
.button:disabled {
  cursor: not-allowed;
  opacity: 0.58;
  transform: none;
}

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

.panel {
  padding: clamp(22px, 4vw, 42px);
}

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

.card {
  padding: 24px;
}

.card:hover {
  border-color: var(--color-border-strong);
  box-shadow: var(--shadow-card);
}

.grid {
  display: grid;
  gap: 24px;
}

.grid > * {
  min-width: 0;
}

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

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

.prose {
  min-width: 0;
}

.prose h2 {
  margin-top: 2.1em;
  scroll-margin-top: 110px;
}

.prose h3 {
  margin-top: 1.7em;
  scroll-margin-top: 110px;
}

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

.prose a {
  overflow-wrap: anywhere;
}

.table-wrap {
  max-width: 100%;
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  -webkit-overflow-scrolling: touch;
}

.data-table {
  width: 100%;
  min-width: 620px;
  background: var(--color-panel);
  color: var(--color-text);
}

.data-table th,
.data-table td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
}

.data-table th {
  background: var(--color-panel-alt);
  color: var(--color-text);
  font-size: 14px;
}

.data-table tr:last-child td {
  border-bottom: 0;
}

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

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

.site-header {
  position: relative;
  z-index: 100;
}

.site-header.is-overlay {
  position: absolute;
  inset: 20px 0 auto;
}

.header-bar {
  position: relative;
  display: flex;
  min-height: 64px;
  align-items: center;
  gap: 22px;
  padding: 9px 12px 9px 16px;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  background: var(--glass-nav);
  color: var(--color-text);
  box-shadow: var(--shadow-nav);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.brand-link {
  display: inline-flex;
  flex-shrink: 0;
  align-items: center;
  gap: 10px;
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  text-decoration: none;
}

.brand-link:hover {
  color: var(--color-accent-dark);
}

.brand-logo {
  width: 34px;
  height: 34px;
  flex-shrink: 0;
}

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

.dot-nav {
  display: flex;
  align-items: center;
  margin: 0;
  padding: 0;
  list-style: none;
}

.dot-nav li {
  display: flex;
  align-items: center;
  margin: 0;
}

.dot-nav li + li::before {
  content: "·";
  margin-inline: 15px;
  color: var(--color-text-muted);
}

.dot-nav a {
  display: flex;
  min-height: 44px;
  align-items: center;
  color: var(--color-text);
  font-size: 14px;
  font-weight: 650;
  text-decoration: none;
}

.dot-nav a:hover,
.dot-nav a.is-active {
  color: var(--color-accent-dark);
}

.header-tools {
  position: relative;
  display: flex;
  flex-shrink: 0;
  align-items: center;
  gap: 5px;
}

.language-button,
.menu-button {
  min-height: 44px;
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--color-text);
  cursor: pointer;
  font-weight: 650;
}

.language-button {
  min-width: 112px;
  padding-inline: 12px;
}

.language-short {
  display: none;
}

.menu-button {
  display: none;
  min-width: 44px;
  padding: 10px;
}

.menu-button span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 4px auto;
  border-radius: var(--radius-pill);
  background: var(--color-text);
}

.language-menu {
  position: absolute;
  top: calc(100% + 9px);
  right: 0;
  width: 174px;
  margin: 0;
  padding: 7px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  color: var(--color-text);
  box-shadow: var(--shadow-card);
  list-style: none;
}

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

.language-menu li {
  margin: 0;
}

.language-menu a {
  display: flex;
  min-height: 44px;
  width: 100%;
  align-items: center;
  padding: 8px 11px;
  border-radius: var(--radius-sm);
  color: var(--color-text);
  text-decoration: none;
}

.language-menu a:hover,
.language-menu a.is-current {
  background: var(--color-accent-soft);
  color: var(--color-accent-dark);
}

.mobile-nav {
  display: none;
}

.nav-veil {
  display: none;
}

.site-footer {
  margin-top: var(--section-space);
  overflow-x: clip;
  border-top: 1px solid var(--color-border);
  background: var(--color-footer-bg);
  color: var(--color-text);
}

.footer-main {
  display: grid;
  grid-template-columns: 1.1fr 0.8fr 1.5fr 0.9fr;
  gap: 36px;
  padding-top: 58px;
  padding-bottom: 44px;
}

.footer-brand p {
  max-width: 300px;
  margin-top: 16px;
  color: var(--color-text-muted);
}

.footer-title {
  margin-bottom: 14px;
  color: var(--color-text);
  font-size: 14px;
  font-weight: 800;
}

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

.footer-links li,
.footer-keywords li,
.footer-languages li {
  margin: 0;
}

.footer-links a,
.footer-keywords a,
.footer-languages a {
  display: inline-flex;
  min-height: 34px;
  align-items: center;
  color: var(--color-text-muted);
  font-size: 14px;
  text-decoration: none;
}

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

.footer-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-keywords a {
  min-height: 32px;
  max-width: 100%;
  overflow: hidden;
  padding: 5px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-text);
}

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

@media (max-width: 900px) {
  .header-shell {
    position: relative;
    z-index: 104;
  }

  .desktop-nav {
    display: none;
  }

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

  .menu-button {
    display: block;
  }

  .mobile-nav {
    position: fixed;
    z-index: 103;
    top: 94px;
    right: var(--gutter);
    left: var(--gutter);
    display: block;
    max-height: calc(100dvh - 110px);
    overflow-y: auto;
    padding: 10px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-panel);
    color: var(--color-text);
    box-shadow: var(--shadow-card);
    overscroll-behavior: contain;
  }

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

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

  .mobile-nav li {
    margin: 0;
  }

  .mobile-nav a {
    display: flex;
    min-height: 48px;
    width: 100%;
    align-items: center;
    padding: 10px 13px;
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-weight: 650;
    text-decoration: none;
  }

  .mobile-nav a:hover,
  .mobile-nav a.is-active,
  .mobile-nav a.is-current {
    background: var(--color-accent-soft);
    color: var(--color-accent-dark);
  }

  .mobile-language-list {
    margin-top: 8px !important;
    padding-top: 8px !important;
    border-top: 1px solid var(--color-border);
  }

  .nav-veil {
    position: fixed;
    z-index: 99;
    inset: 0;
    display: block;
    background: var(--overlay);
  }

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

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

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

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

  h1 {
    font-size: clamp(24px, 7.5vw, 30px);
    line-height: 1.18;
  }

  h2 {
    font-size: clamp(23px, 6.5vw, 29px);
  }

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

  .header-shell {
    padding-inline: var(--gutter);
  }

  .header-bar {
    gap: 8px;
    padding-left: 11px;
  }

  .brand-link {
    min-width: 0;
    font-size: 15px;
  }

  .brand-logo {
    width: 32px;
    height: 32px;
  }

  .language-button {
    min-width: 52px;
    padding-inline: 7px;
  }

  .language-full {
    display: none;
  }

  .language-short {
    display: inline;
  }

  .panel,
  .card {
    padding: 20px;
  }

  .actions {
    align-items: stretch;
  }

  .actions .button {
    flex: 1 1 150px;
  }

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

  .footer-main {
    grid-template-columns: minmax(0, 1fr);
    gap: 30px;
  }

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

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

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

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