/* ==========================================================================
   BiabaApp Docs Stylesheet
   Theme reference: 03_stripe (purple brand + gradient backdrop + modern fintech)
   Brand color override: #DB2777 (rose / hot pink), differentiating from Stripe purple.
   Prefix: bba- (BiabaApp). Independent implementation.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design tokens
   -------------------------------------------------------------------------- */
:root {
  /* brand */
  --bba-brand: #DB2777;
  --bba-brand-2: #BE185D;
  --bba-brand-3: #F472B6;
  --bba-accent: #9333EA;
  --bba-accent-2: #6366F1;
  --bba-grad: linear-gradient(135deg, #DB2777 0%, #9333EA 60%, #6366F1 100%);
  --bba-grad-soft: linear-gradient(135deg, rgba(219,39,119,0.10) 0%, rgba(147,51,234,0.10) 60%, rgba(99,102,241,0.10) 100%);
  --bba-grad-mesh: radial-gradient(900px 540px at 12% 0%, rgba(219,39,119,0.18), transparent 60%),
                   radial-gradient(720px 460px at 88% 0%, rgba(147,51,234,0.14), transparent 65%),
                   radial-gradient(640px 420px at 50% 100%, rgba(99,102,241,0.10), transparent 70%);

  /* surface */
  --bba-bg: #FFFFFF;
  --bba-bg-1: #FCFAFD;
  --bba-bg-2: #F7F4FA;
  --bba-bg-3: #F2EEF6;
  --bba-card: #FFFFFF;
  --bba-card-hover: #FCF7FB;
  --bba-rail-bg: #FBF8FC;

  /* line */
  --bba-line: #ECE6F2;
  --bba-line-2: #E4DCEB;
  --bba-line-strong: #D6CBE0;

  /* text */
  --bba-ink: #1B0A28;
  --bba-ink-soft: #2C1B3A;
  --bba-ink-2: #4B3960;
  --bba-mute: #6E5C82;
  --bba-mute-2: #8E7CA2;

  /* code */
  --bba-code-bg: #1F1024;
  --bba-code-bg-soft: #F6EFF8;
  --bba-code-fg: #F4ECF7;
  --bba-code-pink: #F472B6;
  --bba-code-purple: #C4A1F0;

  /* states */
  --bba-success: #10B981;
  --bba-warn: #F59E0B;
  --bba-danger: #EF4444;
  --bba-info: #6366F1;

  /* radius */
  --bba-r-xs: 5px;
  --bba-r-sm: 8px;
  --bba-r-md: 12px;
  --bba-r-lg: 18px;
  --bba-r-xl: 24px;
  --bba-r-2xl: 32px;

  /* shadow */
  --bba-sh-1: 0 1px 0 rgba(27, 10, 40, 0.04);
  --bba-sh-2: 0 4px 14px -6px rgba(27, 10, 40, 0.10), 0 1px 2px rgba(27, 10, 40, 0.04);
  --bba-sh-3: 0 14px 36px -10px rgba(27, 10, 40, 0.16), 0 4px 12px -6px rgba(27, 10, 40, 0.08);
  --bba-sh-pink: 0 16px 36px -10px rgba(219, 39, 119, 0.30), 0 4px 12px -4px rgba(219, 39, 119, 0.20);
  --bba-sh-ring: 0 0 0 4px rgba(219, 39, 119, 0.18);

  /* font */
  --bba-fs: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --bba-fs-mono: 'SFMono-Regular', Menlo, Consolas, 'Liberation Mono', 'Courier New', monospace;

  /* layout */
  --bba-max: 1240px;
  --bba-rail-w: 264px;
  --bba-toc-w: 232px;
  --bba-nav-h: 64px;
  --bba-prose-w: 760px;
}

[data-theme='dark'] {
  --bba-bg: #100618;
  --bba-bg-1: #150826;
  --bba-bg-2: #1A0B30;
  --bba-bg-3: #20103B;
  --bba-card: #1A0B2C;
  --bba-card-hover: #20113A;
  --bba-rail-bg: #14072A;
  --bba-line: #2A1842;
  --bba-line-2: #34204E;
  --bba-line-strong: #4A2D6A;
  --bba-ink: #F5EFFA;
  --bba-ink-soft: #EADCF2;
  --bba-ink-2: #C8B5DA;
  --bba-mute: #9D8AB4;
  --bba-mute-2: #7E6B95;
  --bba-code-bg: #0A0414;
  --bba-code-bg-soft: #1E0F32;
  --bba-grad-mesh: radial-gradient(900px 540px at 12% 0%, rgba(219,39,119,0.22), transparent 60%),
                   radial-gradient(720px 460px at 88% 0%, rgba(147,51,234,0.20), transparent 65%),
                   radial-gradient(640px 420px at 50% 100%, rgba(99,102,241,0.16), transparent 70%);
  --bba-sh-2: 0 4px 14px -6px rgba(0, 0, 0, 0.6), 0 1px 2px rgba(0, 0, 0, 0.4);
  --bba-sh-3: 0 14px 36px -10px rgba(0, 0, 0, 0.7), 0 4px 12px -6px rgba(0, 0, 0, 0.5);
}

/* --------------------------------------------------------------------------
   2. Reset & base
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: calc(var(--bba-nav-h) + 16px); }
body {
  margin: 0;
  background: var(--bba-bg);
  color: var(--bba-ink);
  font-family: var(--bba-fs);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
img, svg, video { max-width: 100%; height: auto; display: block; }
a { color: var(--bba-brand); text-decoration: none; }
a:hover { color: var(--bba-brand-2); text-decoration: underline; text-underline-offset: 3px; }
button { font: inherit; color: inherit; cursor: pointer; }
input, textarea, select { font: inherit; }
:focus-visible { outline: 2px solid var(--bba-brand); outline-offset: 2px; border-radius: var(--bba-r-xs); }
.bba-skip {
  position: absolute; left: -9999px; top: -9999px;
  padding: 8px 14px; background: var(--bba-brand); color: #fff;
  border-radius: var(--bba-r-sm); z-index: 9999;
}
.bba-skip:focus { left: 12px; top: 12px; }

/* --------------------------------------------------------------------------
   3. Top navigation (sticky, pink underline accent)
   -------------------------------------------------------------------------- */
.bba-nav {
  position: sticky;
  top: 0;
  z-index: 60;
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  background: rgba(255, 255, 255, 0.78);
  border-bottom: 1px solid var(--bba-line);
}
[data-theme='dark'] .bba-nav { background: rgba(16, 6, 24, 0.78); }
.bba-nav__strip {
  height: var(--bba-nav-h);
  display: flex;
  align-items: center;
}
.bba-nav__inner {
  width: 100%;
  max-width: var(--bba-max);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 22px;
}
.bba-nav__left { display: flex; align-items: center; gap: 14px; min-width: 0; }
.bba-nav__burger {
  display: none;
  width: 36px; height: 36px;
  border-radius: var(--bba-r-sm);
  border: 1px solid var(--bba-line);
  background: var(--bba-bg);
  color: var(--bba-ink);
  align-items: center; justify-content: center;
}
.bba-nav__burger:hover { background: var(--bba-bg-2); }

.bba-brand { display: flex; align-items: center; gap: 11px; min-width: 0; color: var(--bba-ink); }
.bba-brand:hover { text-decoration: none; color: var(--bba-ink); }
.bba-brand__mark { display: flex; }
.bba-brand__text { display: flex; flex-direction: column; line-height: 1.05; }
.bba-brand__name {
  font-weight: 800;
  font-size: 17px;
  letter-spacing: -0.4px;
  background: var(--bba-grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.bba-brand__tag {
  font-size: 11px;
  color: var(--bba-mute);
  letter-spacing: 1.2px;
  text-transform: uppercase;
  margin-top: 2px;
}

.bba-nav__primary { display: flex; gap: 4px; margin-left: 6px; }
.bba-nav__link {
  position: relative;
  padding: 7px 13px;
  border-radius: 999px;
  color: var(--bba-ink-2);
  font-size: 14px;
  font-weight: 500;
  transition: color .14s ease, background .14s ease;
}
.bba-nav__link:hover { background: var(--bba-bg-2); color: var(--bba-ink); text-decoration: none; }
.bba-nav__link.is-active {
  color: var(--bba-brand);
  background: rgba(219, 39, 119, 0.08);
}
.bba-nav__link.is-active::after {
  content: '';
  position: absolute;
  left: 14px; right: 14px; bottom: -3px;
  height: 2px;
  background: var(--bba-grad);
  border-radius: 2px;
}

.bba-search {
  position: relative;
  flex: 1;
  max-width: 360px;
  margin-left: auto;
  margin-right: 6px;
}
.bba-search__icon {
  position: absolute;
  left: 12px; top: 50%;
  transform: translateY(-50%);
  color: var(--bba-mute);
  display: flex;
}
.bba-search__input {
  width: 100%;
  height: 38px;
  padding: 0 42px 0 36px;
  border-radius: var(--bba-r-md);
  border: 1px solid var(--bba-line-2);
  background: var(--bba-bg-1);
  color: var(--bba-ink);
  transition: border-color .14s, box-shadow .14s;
}
.bba-search__input::placeholder { color: var(--bba-mute-2); }
.bba-search__input:focus {
  outline: none;
  border-color: var(--bba-brand);
  box-shadow: var(--bba-sh-ring);
  background: var(--bba-bg);
}
.bba-search__kbd {
  position: absolute;
  right: 10px; top: 50%;
  transform: translateY(-50%);
  font-family: var(--bba-fs-mono);
  font-size: 11px;
  background: var(--bba-bg-3);
  color: var(--bba-mute);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--bba-line);
}

.bba-nav__right { display: flex; align-items: center; gap: 8px; }

.bba-lang { position: relative; }
.bba-lang__btn {
  display: flex;
  align-items: center;
  gap: 6px;
  height: 36px;
  padding: 0 12px;
  border: 1px solid var(--bba-line);
  border-radius: var(--bba-r-sm);
  background: var(--bba-bg);
  color: var(--bba-ink);
  font-size: 13px;
}
.bba-lang__btn:hover { background: var(--bba-bg-2); }
.bba-lang__pop {
  position: absolute;
  right: 0; top: calc(100% + 6px);
  min-width: 168px;
  background: var(--bba-bg);
  border: 1px solid var(--bba-line);
  border-radius: var(--bba-r-md);
  box-shadow: var(--bba-sh-3);
  list-style: none;
  margin: 0; padding: 6px;
  display: none;
  z-index: 90;
}
.bba-lang.is-open .bba-lang__pop { display: block; }
.bba-lang__pop li a {
  display: block;
  padding: 7px 10px;
  border-radius: var(--bba-r-xs);
  font-size: 13px;
  color: var(--bba-ink);
}
.bba-lang__pop li a:hover { background: var(--bba-bg-2); text-decoration: none; }
.bba-lang__pop li a.is-here { color: var(--bba-brand); background: rgba(219,39,119,0.06); font-weight: 600; }

.bba-iconbtn {
  width: 36px; height: 36px;
  border: 1px solid var(--bba-line);
  border-radius: var(--bba-r-sm);
  background: var(--bba-bg);
  color: var(--bba-ink);
  display: flex; align-items: center; justify-content: center;
}
.bba-iconbtn:hover { background: var(--bba-bg-2); }
.bba-themebtn__l { display: inline-flex; }
.bba-themebtn__d { display: none; }
[data-theme='dark'] .bba-themebtn__l { display: none; }
[data-theme='dark'] .bba-themebtn__d { display: inline-flex; }

/* --------------------------------------------------------------------------
   4. Layout shell with rail (3-col on article)
   -------------------------------------------------------------------------- */
.bba-shell {
  display: grid;
  grid-template-columns: var(--bba-rail-w) 1fr;
  gap: 0;
  max-width: var(--bba-max);
  margin: 0 auto;
  padding: 0 24px;
  align-items: flex-start;
}
.bba-main {
  min-width: 0;
  padding: 28px 0 80px 36px;
}
.bba-main--full {
  max-width: var(--bba-max);
  margin: 0 auto;
  padding: 0 0 80px 0;
}

/* --------------------------------------------------------------------------
   5. Left rail (doc sidebar)
   -------------------------------------------------------------------------- */
.bba-rail {
  position: sticky;
  top: var(--bba-nav-h);
  align-self: start;
  height: calc(100vh - var(--bba-nav-h));
  background: transparent;
  padding: 22px 18px 22px 0;
  border-right: 1px solid var(--bba-line);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.bba-rail__filter {
  position: relative;
  margin-bottom: 14px;
}
.bba-rail__filter-icon {
  position: absolute;
  left: 10px; top: 50%;
  transform: translateY(-50%);
  color: var(--bba-mute);
  display: flex;
}
.bba-rail__filter-input {
  width: 100%;
  height: 32px;
  padding: 0 10px 0 30px;
  border-radius: var(--bba-r-sm);
  border: 1px solid var(--bba-line-2);
  background: var(--bba-bg-1);
  color: var(--bba-ink);
  font-size: 12.5px;
}
.bba-rail__filter-input:focus { outline: none; border-color: var(--bba-brand); box-shadow: var(--bba-sh-ring); }
.bba-rail__scroll {
  flex: 1;
  overflow-y: auto;
  padding-right: 6px;
}
.bba-rail__scroll::-webkit-scrollbar { width: 6px; }
.bba-rail__scroll::-webkit-scrollbar-track { background: transparent; }
.bba-rail__scroll::-webkit-scrollbar-thumb { background: var(--bba-line-2); border-radius: 3px; }
.bba-rail__scroll::-webkit-scrollbar-thumb:hover { background: var(--bba-line-strong); }
.bba-rail__group {
  margin-bottom: 14px;
  padding-bottom: 12px;
  border-bottom: 1px dashed var(--bba-line);
}
.bba-rail__group:last-child { border-bottom: 0; }
.bba-rail__cap {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--bba-mute);
  padding: 6px 10px 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.bba-rail__cap--button { cursor: pointer; user-select: none; color: var(--bba-ink-2); font-weight: 800; letter-spacing: 0.4px; text-transform: none; font-size: 13px; }
.bba-rail__cap--button:hover { color: var(--bba-brand); }
.bba-rail__chev { display: inline-flex; transition: transform .18s ease; color: var(--bba-mute); }
.bba-rail__group.is-collapsed .bba-rail__chev { transform: rotate(-90deg); }
.bba-rail__group.is-collapsed .bba-rail__list--nested { display: none; }
.bba-rail__count {
  margin-left: auto;
  font-size: 11px;
  color: var(--bba-mute);
  background: var(--bba-bg-2);
  padding: 1px 7px;
  border-radius: 999px;
  font-weight: 600;
  letter-spacing: 0;
}
.bba-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.bba-rail__list--nested {
  border-left: 1px solid var(--bba-line);
  margin-left: 12px;
  padding-left: 4px;
}
.bba-rail__a {
  display: block;
  padding: 5px 10px;
  margin: 1px 0;
  font-size: 13px;
  color: var(--bba-ink-2);
  border-radius: var(--bba-r-xs);
  border-left: 2px solid transparent;
  margin-left: -2px;
  line-height: 1.4;
  transition: color .14s, background .14s;
}
.bba-rail__a:hover { color: var(--bba-brand); background: rgba(219,39,119,0.04); text-decoration: none; }
.bba-rail__a.is-here {
  color: var(--bba-brand);
  background: rgba(219,39,119,0.08);
  border-left-color: var(--bba-brand);
  font-weight: 600;
}
.bba-rail__a--root { font-weight: 600; color: var(--bba-ink); }

/* --------------------------------------------------------------------------
   6. Hero (Stripe-style: gradient mesh, big search, brand pill)
   -------------------------------------------------------------------------- */
.bba-hero {
  position: relative;
  overflow: hidden;
  padding: 72px 24px 80px;
  background: var(--bba-grad-mesh), var(--bba-bg);
  border-bottom: 1px solid var(--bba-line);
}
.bba-hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(219,39,119,0.06) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(147,51,234,0.06) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 60% 70% at 50% 30%, #000 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 60% 70% at 50% 30%, #000 30%, transparent 80%);
  pointer-events: none;
  opacity: 0.7;
}
.bba-hero__glow {
  position: absolute;
  width: 540px; height: 540px;
  left: 50%; top: 60%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, rgba(219,39,119,0.18), transparent 70%);
  filter: blur(40px);
  pointer-events: none;
}
.bba-hero__inner {
  position: relative;
  max-width: 880px;
  margin: 0 auto;
  text-align: center;
  z-index: 1;
}
.bba-hero__pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 13px;
  background: rgba(255,255,255,0.86);
  border: 1px solid var(--bba-line-2);
  border-radius: 999px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--bba-ink-2);
  box-shadow: var(--bba-sh-1);
  margin-bottom: 22px;
}
[data-theme='dark'] .bba-hero__pill { background: rgba(26, 11, 44, 0.7); }
.bba-hero__pillDot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--bba-brand);
  box-shadow: 0 0 0 4px rgba(219,39,119,0.18);
}
.bba-hero__h1 {
  font-size: 56px;
  line-height: 1.08;
  letter-spacing: -1.4px;
  font-weight: 800;
  margin: 0 0 20px;
  background: linear-gradient(180deg, var(--bba-ink) 0%, var(--bba-ink-soft) 45%, var(--bba-brand) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.bba-hero__sub {
  font-size: 18px;
  line-height: 1.6;
  color: var(--bba-ink-2);
  max-width: 680px;
  margin: 0 auto 32px;
}
.bba-hero__search {
  position: relative;
  max-width: 580px;
  margin: 0 auto 18px;
}
.bba-hero__searchIcon {
  position: absolute;
  left: 18px; top: 50%;
  transform: translateY(-50%);
  color: var(--bba-mute);
  display: flex;
}
.bba-hero__searchInput {
  width: 100%;
  height: 56px;
  padding: 0 80px 0 50px;
  border-radius: var(--bba-r-lg);
  border: 1px solid var(--bba-line-2);
  background: var(--bba-bg);
  color: var(--bba-ink);
  font-size: 15px;
  box-shadow: var(--bba-sh-2);
  transition: border-color .14s, box-shadow .14s;
}
.bba-hero__searchInput:focus {
  outline: none;
  border-color: var(--bba-brand);
  box-shadow: var(--bba-sh-pink);
}
.bba-hero__searchKbd {
  position: absolute;
  right: 16px; top: 50%;
  transform: translateY(-50%);
  font-family: var(--bba-fs-mono);
  font-size: 12px;
  background: var(--bba-bg-3);
  color: var(--bba-mute);
  padding: 4px 9px;
  border-radius: 6px;
  border: 1px solid var(--bba-line);
}
.bba-hero__chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
  margin: 18px 0 22px;
}
.bba-hero__chip {
  padding: 6px 14px;
  background: rgba(255,255,255,0.72);
  border: 1px solid var(--bba-line-2);
  border-radius: 999px;
  font-size: 13px;
  color: var(--bba-ink-2);
  transition: all .14s ease;
}
.bba-hero__chip:hover {
  background: #fff;
  color: var(--bba-brand);
  border-color: var(--bba-brand);
  text-decoration: none;
  transform: translateY(-1px);
}
[data-theme='dark'] .bba-hero__chip { background: rgba(26, 11, 44, 0.7); }
[data-theme='dark'] .bba-hero__chip:hover { background: rgba(40, 20, 60, 0.9); }
.bba-hero__cta {
  display: inline-flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 6px;
}

/* --------------------------------------------------------------------------
   7. Buttons
   -------------------------------------------------------------------------- */
.bba-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 10px 18px;
  border-radius: var(--bba-r-md);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: all .14s ease;
  cursor: pointer;
  white-space: nowrap;
}
.bba-btn--primary {
  background: var(--bba-grad);
  color: #fff;
  box-shadow: var(--bba-sh-pink);
}
.bba-btn--primary:hover { transform: translateY(-1px); color: #fff; text-decoration: none; box-shadow: 0 18px 40px -10px rgba(219, 39, 119, 0.4), 0 6px 14px -4px rgba(219, 39, 119, 0.24); }
.bba-btn--ghost {
  background: var(--bba-bg);
  color: var(--bba-ink);
  border-color: var(--bba-line-2);
}
.bba-btn--ghost:hover { border-color: var(--bba-brand); color: var(--bba-brand); text-decoration: none; }
.bba-btn--soft {
  background: rgba(219, 39, 119, 0.08);
  color: var(--bba-brand);
  border-color: rgba(219, 39, 119, 0.18);
}
.bba-btn--soft:hover { background: rgba(219, 39, 119, 0.14); color: var(--bba-brand-2); text-decoration: none; }

/* --------------------------------------------------------------------------
   8. Sections
   -------------------------------------------------------------------------- */
.bba-section {
  padding: 64px 24px;
  border-bottom: 1px solid var(--bba-line);
}
.bba-section--alt { background: var(--bba-bg-1); }
.bba-section__inner {
  max-width: var(--bba-max);
  margin: 0 auto;
}
.bba-section__cap { margin-bottom: 32px; max-width: 720px; }
.bba-section__h2 {
  font-size: 30px;
  line-height: 1.2;
  letter-spacing: -0.6px;
  font-weight: 800;
  margin: 0 0 10px;
  color: var(--bba-ink);
}
.bba-section__p {
  font-size: 16px;
  color: var(--bba-mute);
  margin: 0;
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   9. Card grid (homepage section cards)
   -------------------------------------------------------------------------- */
.bba-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.bba-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 24px 22px 20px;
  background: var(--bba-card);
  border: 1px solid var(--bba-line);
  border-radius: var(--bba-r-lg);
  color: var(--bba-ink);
  transition: all .18s ease;
  overflow: hidden;
}
.bba-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--bba-grad);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .22s ease;
}
.bba-card:hover {
  border-color: var(--bba-line-strong);
  background: var(--bba-card-hover);
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: var(--bba-sh-3);
  color: var(--bba-ink);
}
.bba-card:hover::before { transform: scaleX(1); }
.bba-card__head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 10px;
}
.bba-card__num {
  font-family: var(--bba-fs-mono);
  font-size: 12px;
  color: var(--bba-mute);
  letter-spacing: 1px;
  font-weight: 700;
}
.bba-card__name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.2px;
  color: var(--bba-ink);
}
.bba-card__desc {
  font-size: 14px;
  color: var(--bba-mute);
  line-height: 1.6;
  margin: 0 0 14px;
  flex: 1;
}
.bba-card__list {
  list-style: none;
  margin: 0 0 14px;
  padding: 0;
}
.bba-card__list li {
  font-size: 13px;
  color: var(--bba-ink-2);
  padding: 4px 0;
  display: flex;
  gap: 6px;
  align-items: baseline;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.bba-card__bullet { color: var(--bba-brand); font-weight: 700; }
.bba-card__cta {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  font-weight: 600;
  color: var(--bba-brand);
  margin-top: auto;
}
.bba-card:hover .bba-card__cta svg { transform: translateX(2px); }
.bba-card__cta svg { transition: transform .18s ease; }
.bba-card__count {
  font-size: 12.5px;
  color: var(--bba-mute);
  font-weight: 600;
  letter-spacing: 0.2px;
  margin-top: auto;
  padding-top: 8px;
  border-top: 1px dashed var(--bba-line);
}

/* mini cards (more categories) */
.bba-mini {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
.bba-mini__item {
  padding: 16px 16px;
  background: var(--bba-card);
  border: 1px solid var(--bba-line);
  border-radius: var(--bba-r-md);
  color: var(--bba-ink);
  transition: all .14s ease;
}
.bba-mini__item:hover {
  border-color: var(--bba-brand);
  background: var(--bba-card-hover);
  color: var(--bba-ink);
  text-decoration: none;
  transform: translateY(-1px);
}
.bba-mini__name {
  font-size: 14.5px;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--bba-ink);
}
.bba-mini__desc {
  font-size: 12.5px;
  color: var(--bba-mute);
  margin: 0;
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* --------------------------------------------------------------------------
   10. Feed (latest articles list)
   -------------------------------------------------------------------------- */
.bba-feed {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
}
.bba-feed__row {
  padding: 22px 0;
  border-bottom: 1px solid var(--bba-line);
  display: flex;
  gap: 18px;
}
.bba-feed__row:first-child { padding-top: 4px; }
.bba-feed__row:last-child { border-bottom: 0; }
.bba-feed__main { flex: 1; min-width: 0; }
.bba-feed__title {
  display: block;
  font-size: 17px;
  font-weight: 700;
  color: var(--bba-ink);
  margin-bottom: 6px;
  letter-spacing: -0.2px;
  line-height: 1.4;
}
.bba-feed__title:hover { color: var(--bba-brand); text-decoration: none; }
.bba-feed__desc {
  font-size: 14px;
  color: var(--bba-mute);
  line-height: 1.6;
  margin: 0 0 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.bba-feed__meta {
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 12.5px;
  color: var(--bba-mute);
}
.bba-feed__date { font-family: var(--bba-fs-mono); letter-spacing: 0.2px; }
.bba-feed__chip {
  display: inline-flex;
  padding: 2px 9px;
  background: rgba(219,39,119,0.08);
  color: var(--bba-brand);
  border-radius: 999px;
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.1px;
}

.bba-viewall {
  margin-top: 24px;
  text-align: center;
}
.bba-viewall a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 20px;
  border-radius: 999px;
  background: var(--bba-bg-2);
  color: var(--bba-ink);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid var(--bba-line-2);
}
.bba-viewall a:hover { background: var(--bba-grad); color: #fff; border-color: transparent; text-decoration: none; }

/* --------------------------------------------------------------------------
   11. FAQ accordion
   -------------------------------------------------------------------------- */
.bba-faq {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: 880px;
}
.bba-faq__row {
  background: var(--bba-card);
  border: 1px solid var(--bba-line);
  border-radius: var(--bba-r-md);
  overflow: hidden;
  transition: border-color .14s, box-shadow .14s;
}
.bba-faq__row[open] {
  border-color: var(--bba-brand);
  box-shadow: var(--bba-sh-2);
}
.bba-faq__q {
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--bba-ink);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 10px;
}
.bba-faq__q::-webkit-details-marker { display: none; }
.bba-faq__qIco {
  display: inline-flex;
  color: var(--bba-mute);
  transition: transform .18s ease;
  flex-shrink: 0;
}
.bba-faq__row[open] .bba-faq__qIco {
  transform: rotate(90deg);
  color: var(--bba-brand);
}
.bba-faq__a {
  padding: 0 20px 18px 38px;
  color: var(--bba-ink-2);
  font-size: 14.5px;
  line-height: 1.7;
}
.bba-faq__a p { margin: 0 0 8px; }

.bba-link {
  color: var(--bba-brand);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* --------------------------------------------------------------------------
   12. Document pages (post / page / list / category)
   -------------------------------------------------------------------------- */
.bba-doc {
  max-width: 100%;
  padding: 28px 0 16px;
}
.bba-doc--page { max-width: 880px; }

.bba-crumb {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  font-size: 12.5px;
  color: var(--bba-mute);
  margin-bottom: 18px;
}
.bba-crumb__link { color: var(--bba-mute); }
.bba-crumb__link:hover { color: var(--bba-brand); }
.bba-crumb__sep { color: var(--bba-mute-2); }
.bba-crumb__here {
  color: var(--bba-ink);
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 60%;
}

.bba-doc__head {
  padding-bottom: 24px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--bba-line);
}
.bba-doc__kicker {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 1.4px;
  text-transform: uppercase;
  color: var(--bba-brand);
  margin-bottom: 14px;
}
.bba-doc__kicker-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--bba-brand);
  box-shadow: 0 0 0 3px rgba(219,39,119,0.18);
}
.bba-doc__h1 {
  font-size: 38px;
  line-height: 1.2;
  letter-spacing: -0.8px;
  font-weight: 800;
  margin: 0 0 14px;
  color: var(--bba-ink);
}
.bba-doc__lede {
  font-size: 17px;
  line-height: 1.65;
  color: var(--bba-ink-2);
  margin: 0 0 18px;
  max-width: 720px;
}
.bba-doc__meta {
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 13px;
  color: var(--bba-mute);
  flex-wrap: wrap;
}
.bba-meta-lab { color: var(--bba-mute-2); margin-right: 2px; }
.bba-meta-dot { color: var(--bba-line-strong); }
.bba-pill {
  display: inline-flex;
  padding: 3px 10px;
  background: rgba(219,39,119,0.08);
  color: var(--bba-brand);
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
}

/* document body grid (article + toc) */
.bba-doc__body {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--bba-toc-w);
  gap: 36px;
  align-items: start;
}

/* --------------------------------------------------------------------------
   13. Prose typography (article body)
   -------------------------------------------------------------------------- */
.bba-prose {
  max-width: var(--bba-prose-w);
  font-size: 16px;
  line-height: 1.78;
  color: var(--bba-ink-soft);
}
.bba-doc--page .bba-prose { max-width: 100%; }

.bba-prose > * { margin-top: 0; }
.bba-prose p { margin: 0 0 18px; }
.bba-prose h2 {
  font-size: 26px;
  line-height: 1.3;
  letter-spacing: -0.4px;
  font-weight: 800;
  margin: 44px 0 14px;
  padding-top: 6px;
  color: var(--bba-ink);
  position: relative;
  scroll-margin-top: 88px;
}
.bba-prose h2::before {
  content: '';
  position: absolute;
  left: -14px; top: 14px;
  width: 4px; height: 22px;
  background: var(--bba-grad);
  border-radius: 4px;
}
.bba-prose h3 {
  font-size: 19px;
  line-height: 1.4;
  font-weight: 700;
  margin: 30px 0 10px;
  color: var(--bba-ink);
  scroll-margin-top: 88px;
}
.bba-prose h4 {
  font-size: 16px;
  font-weight: 700;
  margin: 22px 0 8px;
  color: var(--bba-ink);
}
.bba-prose ul, .bba-prose ol {
  margin: 0 0 18px;
  padding-left: 24px;
}
.bba-prose ul li, .bba-prose ol li {
  margin: 6px 0;
}
.bba-prose ul li::marker { color: var(--bba-brand); }
.bba-prose ol li::marker { color: var(--bba-brand); font-weight: 700; }
.bba-prose strong { color: var(--bba-ink); font-weight: 700; }
.bba-prose em { color: var(--bba-ink-2); }
.bba-prose a {
  color: var(--bba-brand);
  text-decoration: underline;
  text-decoration-color: rgba(219,39,119,0.32);
  text-underline-offset: 3px;
  font-weight: 500;
}
.bba-prose a:hover {
  color: var(--bba-brand-2);
  text-decoration-color: var(--bba-brand-2);
}
.bba-prose blockquote {
  margin: 22px 0;
  padding: 14px 18px;
  border-left: 3px solid var(--bba-brand);
  background: var(--bba-bg-2);
  border-radius: 0 var(--bba-r-md) var(--bba-r-md) 0;
  color: var(--bba-ink-2);
}
.bba-prose blockquote p:last-child { margin-bottom: 0; }
.bba-prose hr {
  border: 0;
  height: 1px;
  background: var(--bba-line);
  margin: 36px 0;
}

/* inline code */
.bba-prose code {
  font-family: var(--bba-fs-mono);
  font-size: 0.88em;
  padding: 1px 6px;
  background: var(--bba-code-bg-soft);
  color: var(--bba-brand-2);
  border-radius: 4px;
  border: 1px solid var(--bba-line);
}

/* fenced code blocks */
.bba-prose pre {
  position: relative;
  background: var(--bba-code-bg);
  color: var(--bba-code-fg);
  padding: 18px 18px;
  border-radius: var(--bba-r-md);
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.65;
  margin: 22px 0;
  border: 1px solid var(--bba-line);
}
.bba-prose pre code {
  background: transparent;
  color: inherit;
  border: 0;
  padding: 0;
  font-size: inherit;
}
.bba-copy {
  position: absolute;
  top: 10px; right: 10px;
  padding: 4px 10px;
  background: rgba(255,255,255,0.10);
  color: var(--bba-code-fg);
  border: 1px solid rgba(255,255,255,0.14);
  border-radius: 6px;
  font-size: 11.5px;
  font-family: var(--bba-fs);
  cursor: pointer;
  opacity: 0;
  transition: opacity .14s ease;
}
.bba-prose pre:hover .bba-copy { opacity: 1; }
.bba-copy:hover { background: rgba(255,255,255,0.18); }

/* tables */
.bba-prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 22px 0;
  font-size: 14px;
  overflow: hidden;
  border-radius: var(--bba-r-md);
  border: 1px solid var(--bba-line);
}
.bba-prose thead {
  background: var(--bba-bg-2);
}
.bba-prose th {
  padding: 11px 14px;
  text-align: left;
  font-weight: 700;
  font-size: 13px;
  color: var(--bba-ink);
  letter-spacing: 0.1px;
  border-bottom: 1px solid var(--bba-line);
}
.bba-prose td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--bba-line);
  color: var(--bba-ink-2);
  vertical-align: top;
}
.bba-prose tbody tr:last-child td { border-bottom: 0; }
.bba-prose tbody tr:hover td { background: var(--bba-bg-1); }

/* --------------------------------------------------------------------------
   14. Right-side TOC
   -------------------------------------------------------------------------- */
.bba-toc {
  position: sticky;
  top: calc(var(--bba-nav-h) + 16px);
  align-self: start;
  max-height: calc(100vh - var(--bba-nav-h) - 32px);
}
.bba-toc__inner {
  padding: 16px 4px 12px 16px;
  border-left: 1px solid var(--bba-line);
  overflow-y: auto;
  max-height: inherit;
}
.bba-toc__inner::-webkit-scrollbar { width: 4px; }
.bba-toc__inner::-webkit-scrollbar-thumb { background: var(--bba-line-2); border-radius: 2px; }
.bba-toc__cap {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.4px;
  text-transform: uppercase;
  color: var(--bba-mute);
  margin-bottom: 10px;
}
.bba-toc__list {
  list-style: none;
  margin: 0 0 14px;
  padding: 0;
}
.bba-toc__row { margin: 2px 0; }
.bba-toc__row--lv2 { padding-left: 0; }
.bba-toc__row--lv3 { padding-left: 12px; }
.bba-toc__a {
  display: block;
  padding: 4px 8px;
  font-size: 12.5px;
  color: var(--bba-mute);
  border-left: 2px solid transparent;
  margin-left: -2px;
  border-radius: 0 var(--bba-r-xs) var(--bba-r-xs) 0;
  line-height: 1.45;
}
.bba-toc__a:hover { color: var(--bba-ink); text-decoration: none; }
.bba-toc__a.is-active {
  color: var(--bba-brand);
  border-left-color: var(--bba-brand);
  font-weight: 600;
  background: rgba(219,39,119,0.06);
}
.bba-toc__list--plain .bba-toc__a { padding-left: 8px; }
.bba-toc__hr {
  height: 1px;
  background: var(--bba-line);
  margin: 14px 0 12px;
}

/* --------------------------------------------------------------------------
   15. Prev/next navigation
   -------------------------------------------------------------------------- */
.bba-pn {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 50px;
  padding-top: 30px;
  border-top: 1px solid var(--bba-line);
}
.bba-pn__card {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 18px;
  background: var(--bba-card);
  border: 1px solid var(--bba-line);
  border-radius: var(--bba-r-md);
  color: var(--bba-ink);
  transition: all .14s ease;
}
.bba-pn__card:hover {
  border-color: var(--bba-brand);
  background: var(--bba-card-hover);
  color: var(--bba-ink);
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: var(--bba-sh-2);
}
.bba-pn__card--next { text-align: right; }
.bba-pn__lab {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 11.5px;
  color: var(--bba-mute);
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
}
.bba-pn__card--next .bba-pn__lab { justify-content: flex-end; }
.bba-pn__t {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--bba-ink);
  line-height: 1.4;
}

/* --------------------------------------------------------------------------
   16. Pager (URL pagination)
   -------------------------------------------------------------------------- */
.bba-pager {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-top: 36px;
  padding: 16px 0;
  border-top: 1px solid var(--bba-line);
  flex-wrap: wrap;
}
.bba-pager__nav {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border: 1px solid var(--bba-line-2);
  border-radius: var(--bba-r-sm);
  background: var(--bba-bg);
  color: var(--bba-ink);
  font-size: 13px;
  font-weight: 600;
}
.bba-pager__nav:hover { border-color: var(--bba-brand); color: var(--bba-brand); text-decoration: none; }
.bba-pager__nav.is-off { color: var(--bba-mute-2); cursor: not-allowed; opacity: 0.6; }
.bba-pager__nums { display: flex; gap: 4px; }
.bba-pager__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 32px;
  height: 32px;
  padding: 0 8px;
  border-radius: var(--bba-r-sm);
  font-size: 13px;
  font-weight: 600;
  color: var(--bba-ink-2);
}
.bba-pager__num:hover { background: var(--bba-bg-2); color: var(--bba-brand); text-decoration: none; }
.bba-pager__num.is-here {
  background: var(--bba-grad);
  color: #fff;
}

/* --------------------------------------------------------------------------
   17. Footer
   -------------------------------------------------------------------------- */
.bba-foot {
  margin-top: 60px;
  background: var(--bba-bg-1);
  border-top: 1px solid var(--bba-line);
}
.bba-foot__top {
  max-width: var(--bba-max);
  margin: 0 auto;
  padding: 56px 24px 36px;
  display: grid;
  grid-template-columns: 1.4fr 3fr;
  gap: 40px;
}
.bba-foot__brand { max-width: 320px; }
.bba-foot__logo {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.6px;
  background: var(--bba-grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
}
.bba-foot__line {
  font-size: 13.5px;
  color: var(--bba-mute);
  line-height: 1.6;
  margin: 0 0 14px;
}
.bba-foot__badges { display: flex; gap: 6px; flex-wrap: wrap; }
.bba-foot__badge {
  font-size: 11px;
  padding: 3px 10px;
  background: var(--bba-bg);
  border: 1px solid var(--bba-line);
  border-radius: 999px;
  color: var(--bba-ink-2);
  font-weight: 600;
  letter-spacing: 0.2px;
}
.bba-foot__cols {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.bba-foot__col { min-width: 0; }
.bba-foot__h {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.3px;
  text-transform: uppercase;
  color: var(--bba-ink);
  margin-bottom: 12px;
}
.bba-foot__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.bba-foot__list li { margin: 6px 0; }
.bba-foot__list a {
  font-size: 13px;
  color: var(--bba-mute);
}
.bba-foot__list a:hover { color: var(--bba-brand); text-decoration: none; }
.bba-foot__lang {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}
.bba-foot__lang li a {
  display: inline-flex;
  padding: 3px 9px;
  font-size: 11.5px;
  border: 1px solid var(--bba-line);
  border-radius: 999px;
  color: var(--bba-mute);
}
.bba-foot__lang li a:hover { border-color: var(--bba-brand); color: var(--bba-brand); text-decoration: none; }
.bba-foot__lang li a.is-here {
  background: var(--bba-brand);
  border-color: var(--bba-brand);
  color: #fff;
}

.bba-foot__bot {
  border-top: 1px solid var(--bba-line);
  padding: 18px 24px;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 18px;
  max-width: var(--bba-max);
  margin: 0 auto;
  flex-wrap: wrap;
}
.bba-foot__rights {
  font-size: 12px;
  color: var(--bba-mute);
}
.bba-foot__risk {
  font-size: 11.5px;
  color: var(--bba-mute-2);
  max-width: 720px;
  line-height: 1.55;
}

/* --------------------------------------------------------------------------
   18. 404 page
   -------------------------------------------------------------------------- */
.bba-404 {
  max-width: 640px;
  margin: 0 auto;
  padding: 80px 24px;
  text-align: center;
}
.bba-404__code {
  font-size: 92px;
  font-weight: 900;
  letter-spacing: -3px;
  background: var(--bba-grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 16px;
}
.bba-404__h1 {
  font-size: 26px;
  font-weight: 700;
  margin: 0 0 12px;
}
.bba-404__p {
  font-size: 15px;
  color: var(--bba-mute);
  margin: 0 0 28px;
}
.bba-404__cta {
  display: inline-flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
}

/* --------------------------------------------------------------------------
   19. Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 1100px) {
  .bba-cards { grid-template-columns: repeat(2, 1fr); }
  .bba-mini { grid-template-columns: repeat(3, 1fr); }
  .bba-foot__top { grid-template-columns: 1fr; gap: 28px; }
  .bba-doc__body { grid-template-columns: 1fr; }
  .bba-toc { position: static; max-height: none; display: none; }
}

@media (max-width: 920px) {
  :root { --bba-rail-w: 240px; }
  .bba-shell { grid-template-columns: 1fr; padding: 0 18px; }
  .bba-rail {
    position: fixed;
    top: var(--bba-nav-h);
    left: 0;
    width: 280px;
    height: calc(100vh - var(--bba-nav-h));
    background: var(--bba-bg);
    border-right: 1px solid var(--bba-line);
    transform: translateX(-100%);
    transition: transform .22s ease;
    z-index: 80;
    padding: 18px 14px;
    box-shadow: var(--bba-sh-3);
  }
  .bba-rail.is-open { transform: translateX(0); }
  .bba-main { padding: 24px 0 60px; }
  .bba-nav__primary { display: none; }
  .bba-nav__burger { display: inline-flex; }
  .bba-search { max-width: 220px; }
  .bba-hero { padding: 50px 18px 56px; }
  .bba-hero__h1 { font-size: 38px; }
  .bba-hero__sub { font-size: 16px; }
  .bba-section { padding: 44px 18px; }
  .bba-section__h2 { font-size: 24px; }
  .bba-foot__cols { grid-template-columns: repeat(2, 1fr); }
  .bba-doc__h1 { font-size: 28px; }
}

@media (max-width: 640px) {
  .bba-cards { grid-template-columns: 1fr; }
  .bba-mini { grid-template-columns: 1fr 1fr; }
  .bba-search { display: none; }
  .bba-search__kbd { display: none; }
  .bba-hero__h1 { font-size: 32px; letter-spacing: -1px; }
  .bba-hero__searchInput { height: 50px; font-size: 14px; padding: 0 60px 0 44px; }
  .bba-hero__searchKbd { display: none; }
  .bba-hero__cta { flex-direction: column; align-items: stretch; }
  .bba-pn { grid-template-columns: 1fr; }
  .bba-pn__card--next { text-align: left; }
  .bba-pn__card--next .bba-pn__lab { justify-content: flex-start; }
  .bba-pager { justify-content: center; }
  .bba-pager__nav { padding: 6px 10px; font-size: 12px; }
  .bba-pager__nums { order: -1; flex-basis: 100%; justify-content: center; margin-bottom: 6px; }
  .bba-foot__cols { grid-template-columns: 1fr 1fr; gap: 16px; }
  .bba-foot__bot { flex-direction: column; }
  .bba-doc__h1 { font-size: 24px; }
  .bba-doc__lede { font-size: 15px; }
  .bba-prose { font-size: 15.5px; }
  .bba-prose h2 { font-size: 22px; }
  .bba-prose h3 { font-size: 17px; }
}

/* --------------------------------------------------------------------------
   20. Body when sidebar is open on mobile
   -------------------------------------------------------------------------- */
body.bba-rail-open { overflow: hidden; }
body.bba-rail-open::after {
  content: '';
  position: fixed;
  inset: var(--bba-nav-h) 0 0 0;
  background: rgba(20, 7, 42, 0.5);
  z-index: 70;
}

/* --------------------------------------------------------------------------
   21. Accessibility & motion
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
    animation: none !important;
  }
  html { scroll-behavior: auto; }
}

/* --------------------------------------------------------------------------
   22. Print
   -------------------------------------------------------------------------- */
@media print {
  .bba-nav, .bba-rail, .bba-toc, .bba-pn, .bba-foot, .bba-pager { display: none !important; }
  .bba-main { padding: 0; }
  .bba-prose { max-width: 100%; }
  .bba-prose pre { border: 1px solid #ccc; background: #f7f7f7; color: #000; }
  .bba-prose pre code { color: inherit; }
}