:root {
  --color-bg: #1D1332;
  --color-panel: #2A1C4E;
  --color-panel-strong: #362463;
  --color-line: #3EE6F0;
  --color-accent: #FF3D8A;
  --color-accent-deep: #C91E67;
  --color-text: #F4F0FB;
  --color-muted: #A99CCB;
  --color-success: #6FE3A5;
  --color-warning: #F5E14B;
  --color-error: #FF6157;
  --color-header: rgba(29, 19, 50, 0.86);
  --color-panel-glass: rgba(42, 28, 78, 0.9);
  --color-panel-soft: rgba(42, 28, 78, 0.7);
  --color-line-soft: rgba(62, 230, 240, 0.35);
  --color-line-faint: rgba(62, 230, 240, 0.16);
  --color-cyan-wash: rgba(62, 230, 240, 0.07);
  --color-cyan-glow: rgba(62, 230, 240, 0.16);
  --color-pink-wash: rgba(255, 61, 138, 0.07);
  --color-pink-glow: rgba(255, 61, 138, 0.35);
  --color-pink-glow-strong: rgba(255, 61, 138, 0.45);
  --color-pink-led: rgba(255, 61, 138, 0.8);
  --color-beam: rgba(245, 225, 75, 0.4);
  --color-beam-out: rgba(245, 225, 75, 0.04);
  --color-star-strong: rgba(244, 240, 251, 0.75);
  --color-star-mid: rgba(244, 240, 251, 0.55);
  --color-star-soft: rgba(169, 156, 203, 0.5);
  --color-flag-red: #D94A62;
  --color-flag-blue: #3659A8;
  --color-flag-white: #F4F0FB;
  --color-flag-dark: #1D1332;
  --color-flag-hk: #D62F55;
  --color-flag-sg: #E44B64;
  --color-flag-korea-blue: #3B65AE;
  --font-display: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', monospace;
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-control: 10px;
  --radius-panel: 14px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --header-height: 64px;
  --content-max: 1180px;
  --content-wide: 1280px;
  --prose-max: 800px;
  --gutter: clamp(16px, 4vw, 32px);
  --section-space: clamp(64px, 9vw, 112px);
  --shadow-cyan: 0 0 20px var(--color-cyan-glow);
  --shadow-pink: 0 6px 26px var(--color-pink-glow);
  --shadow-pink-hover: 0 10px 32px var(--color-pink-glow-strong);
  --transition-fast: 150ms ease;
  --transition-reveal: 650ms cubic-bezier(0.2, 0.7, 0.2, 1);
  --toc-offset: 86px;
}

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

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

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  margin: 0;
  overflow-x: clip;
  color: var(--color-text);
  background: var(--color-bg);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  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;
  cursor: pointer;
}

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

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

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

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

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

h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 6vw, 72px);
  font-weight: 900;
  letter-spacing: -0.02em;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(34px, 4vw, 48px);
  font-weight: 850;
  letter-spacing: -0.018em;
}

h3 {
  margin-bottom: 14px;
  font-size: clamp(22px, 2.5vw, 28px);
  font-weight: 800;
}

h4 {
  margin-bottom: 10px;
  font-size: 18px;
  font-weight: 750;
}

p {
  margin-bottom: 1.2em;
}

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

li + li {
  margin-top: 0.45em;
}

strong {
  color: var(--color-text);
}

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

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

code {
  overflow-wrap: anywhere;
  color: var(--color-warning);
}

pre {
  max-width: 100%;
  margin: 24px 0;
  overflow-x: auto;
  border: var(--border-thin) solid var(--color-line-soft);
  border-radius: var(--radius-control);
  background: var(--color-panel);
  padding: 20px;
  color: var(--color-text);
  -webkit-overflow-scrolling: touch;
}

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

hr {
  margin: 48px 0;
  border: 0;
  border-top: var(--border-thin) solid var(--color-line-faint);
}

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

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

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

.prose h2,
.prose h3 {
  scroll-margin-top: var(--toc-offset);
}

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

.prose h3 {
  margin-top: 1.65em;
}

.prose a {
  color: var(--color-line);
  text-decoration: underline;
  text-decoration-color: var(--color-line-soft);
  text-underline-offset: 0.2em;
}

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

.section-compact {
  padding-top: clamp(40px, 6vw, 72px);
  padding-bottom: clamp(40px, 6vw, 72px);
  overflow-x: clip;
}

.section-head {
  max-width: 760px;
  margin: 0 auto 44px;
  text-align: center;
}

.section-head p {
  color: var(--color-muted);
  font-size: 18px;
}

.keyword-lock,
.nowrap-word {
  white-space: nowrap;
}

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

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

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

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

.mono {
  font-family: var(--font-mono);
}

.panel,
.card {
  min-width: 0;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-panel);
  background: var(--color-panel);
  box-shadow: var(--shadow-cyan);
}

.panel {
  padding: clamp(22px, 4vw, 36px);
}

.card {
  padding: 24px;
}

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

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

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

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

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

.flex-row > svg,
.flex-row > img,
.flex-row > .dot,
.flex-row > .icon {
  flex-shrink: 0;
}

.badge,
.eyebrow {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  border: var(--border-thin) solid var(--color-line-soft);
  border-radius: var(--radius-pill);
  background: var(--color-panel-soft);
  padding: 6px 14px;
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  overflow: hidden;
}

.badge-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 8px var(--color-pink-led);
}

.tag {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  border: var(--border-thin) solid var(--color-line-soft);
  border-radius: var(--radius-xs);
  padding: 4px 9px;
  color: var(--color-line);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.4;
  overflow: hidden;
}

.btn {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-control);
  padding: 12px 30px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 750;
  line-height: 1.2;
  text-align: center;
  transition:
    transform var(--transition-fast),
    border-color var(--transition-fast),
    background var(--transition-fast),
    box-shadow var(--transition-fast);
}

.btn svg {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  color: var(--color-text);
  background: var(--color-accent);
  box-shadow: var(--shadow-pink);
}

.btn-primary:hover {
  box-shadow: var(--shadow-pink-hover);
}

.btn-primary:active {
  transform: translateY(0);
  background: var(--color-accent-deep);
}

.btn-secondary {
  border-color: var(--color-line-soft);
  color: var(--color-line);
  background: transparent;
}

.btn-secondary:hover {
  border-color: var(--color-line);
  background: var(--color-cyan-wash);
}

.btn-muted {
  border-color: var(--color-line-faint);
  color: var(--color-text);
  background: var(--color-panel);
}

.btn[disabled],
.btn.is-disabled {
  cursor: not-allowed;
  opacity: 0.48;
  transform: none;
}

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

.header-shell {
  display: flex;
  min-height: var(--header-height);
  align-items: center;
  gap: 22px;
  padding-inline: var(--gutter);
}

.site-brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 9px;
}

.site-brand img {
  width: 27px;
  height: 27px;
}

.brand-word {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 850;
  letter-spacing: 0.02em;
}

.brand-local {
  color: var(--color-muted);
  font-size: 12px;
  font-weight: 500;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-inline: auto;
}

.desktop-nav a {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  gap: 6px;
  border-radius: var(--radius-sm);
  padding: 7px 9px;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1;
  white-space: nowrap;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.desktop-nav a svg {
  width: 15px;
  height: 15px;
  flex: 0 0 auto;
}

.desktop-nav a:hover,
.desktop-nav a.is-active {
  color: var(--color-text);
}

.desktop-nav a.is-active {
  background: var(--color-panel);
}

.header-tools {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 10px;
}

.language-wrap {
  position: relative;
}

.language-button {
  min-height: 40px;
  border-radius: var(--radius-sm);
  background: transparent;
  padding: 6px 8px;
  color: var(--color-muted);
  font-size: 13px;
}

.language-button:hover {
  color: var(--color-text);
}

.language-menu {
  position: absolute;
  top: calc(100% + 9px);
  right: 0;
  z-index: 90;
  display: none;
  width: 160px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-control);
  background: var(--color-panel);
  box-shadow: var(--shadow-cyan);
  padding: 6px;
}

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

.language-menu a {
  display: flex;
  min-height: 42px;
  align-items: center;
  border-radius: var(--radius-sm);
  padding: 8px 11px;
  color: var(--color-muted);
  font-size: 13px;
}

.language-menu a:hover,
.language-menu a[aria-current="true"] {
  color: var(--color-text);
  background: var(--color-panel-strong);
}

.header-login {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  border: var(--border-thin) solid var(--color-line-soft);
  border-radius: var(--radius-control);
  background: var(--color-panel);
  padding: 8px 18px;
  color: var(--color-text);
  font-size: 13px;
  font-weight: 700;
  box-shadow: var(--shadow-cyan);
}

.header-login:hover {
  border-color: var(--color-line);
}

.menu-toggle {
  display: none;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-text);
}

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

.mobile-nav {
  display: none;
}

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

.mobile-nav-inner {
  padding: 8px var(--gutter) 16px;
}

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 46px;
  align-items: center;
  gap: 11px;
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  color: var(--color-muted);
}

.mobile-nav a svg {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
}

.mobile-nav a:hover,
.mobile-nav a.is-active {
  color: var(--color-text);
  background: var(--color-panel-strong);
}

.mobile-language-list {
  margin-top: 8px;
  border-top: var(--border-thin) solid var(--color-line-faint);
  padding-top: 8px;
}

.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 60;
  display: none;
  background: var(--color-header);
}

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

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

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1.2fr 0.8fr;
  gap: 36px;
  padding-top: 58px;
  padding-bottom: 42px;
}

.footer-brand p {
  max-width: 330px;
  color: var(--color-muted);
  font-size: 14px;
}

.footer-title {
  margin-bottom: 15px;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.footer-links {
  display: grid;
  gap: 8px;
}

.footer-links a {
  color: var(--color-muted);
  font-size: 14px;
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-top: var(--border-thin) solid var(--color-line-faint);
  padding-top: 22px;
  padding-bottom: 24px;
  color: var(--color-muted);
  font-size: 13px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.reveal {
  transition: opacity var(--transition-reveal), transform var(--transition-reveal);
}

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

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

.tilt {
  transform: rotate(-1deg);
}

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

@media (max-width: 1120px) {
  .desktop-nav a {
    padding-inline: 7px;
  }

  .desktop-nav a svg {
    display: none;
  }

  .brand-local {
    display: none;
  }
}

@media (max-width: 900px) {
  .desktop-nav,
  .language-wrap {
    display: none;
  }

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

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

  .site-header {
    z-index: 80;
  }

  .mobile-nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    z-index: 85;
    max-height: calc(100dvh - var(--header-height));
    overflow-y: auto;
    overscroll-behavior: contain;
    border-bottom: var(--border-thin) solid var(--color-line);
    background: var(--color-panel);
  }

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

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

@media (max-width: 768px) {
  h1 {
    font-size: clamp(28px, 9.5vw, 40px);
    line-height: 1.14;
  }

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

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

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

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

  .brand-word {
    font-size: 17px;
  }

  .header-login {
    min-width: 58px;
    padding-inline: 12px;
  }

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

  .btn {
    max-width: 100%;
  }

  .tilt {
    transform: none;
  }

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

@media (max-width: 374px) {
  .site-brand img {
    width: 24px;
    height: 24px;
  }

  .brand-local {
    display: none;
  }

  .header-login {
    padding-inline: 10px;
  }
}

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

  *,
  *::before,
  *::after {
    animation: none !important;
    scroll-behavior: auto !important;
    transition: none !important;
  }

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