@import url("https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;600;700&display=swap");

:root {
  --bkc-bg: #0f0e1a;
  --bkc-surface: rgba(255, 255, 255, 0.06);
  --bkc-glass: rgba(28, 24, 52, 0.72);
  --bkc-magenta: #ff4d9a;
  --bkc-cyan: #42f0dc;
  --bkc-peach: #ffab7a;
  --bkc-violet: #8b6cff;
  --bkc-text: #f2eef8;
  --bkc-muted: #a89ec4;
  --bkc-line: rgba(255, 255, 255, 0.1);
  --bkc-radius: 18px;
  --bkc-dl-h: 0px;
  --bkc-header-h: 64px;
  --bkc-max: 1180px;
  font-family: "Noto Sans SC", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bkc-bg);
  color: var(--bkc-text);
  line-height: 1.75;
  font-size: 16px;
  overflow-x: hidden;
}

body.bkc-dl-pad {
  padding-top: var(--bkc-dl-h);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--bkc-cyan);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--bkc-peach);
}

h1, h2, h3, h4 {
  line-height: 1.35;
  margin: 0 0 0.75em;
  font-weight: 700;
}

h1 { font-size: clamp(1.75rem, 4vw, 2.6rem); }
h2 { font-size: clamp(1.35rem, 3vw, 1.85rem); }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.35rem); }

p { margin: 0 0 1em; }

ul, ol { margin: 0 0 1em; padding-left: 1.25em; }

.bkc-wrap {
  width: min(var(--bkc-max), 92vw);
  margin: 0 auto;
}

/* Top download strip */
.bkc-dl-top {
  background: linear-gradient(90deg, #1a1535, #251a48, #1a1535);
  border-bottom: 1px solid var(--bkc-line);
  padding: 14px 0 10px;
}

.bkc-dl-top-head {
  text-align: center;
  font-size: 0.88rem;
  color: var(--bkc-muted);
  margin-bottom: 10px;
}

#ads {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 14px;
  max-width: 720px;
  margin: 0 auto;
  min-height: 78px;
}

.bkc-ad-cell {
  width: 72px;
  text-align: center;
  flex-shrink: 0;
}

.bkc-ad-cell figure {
  margin: 0;
}

.bkc-ad-cell a {
  display: inline-block;
  line-height: 0;
}

.bkc-ad-cell img,
#ads img {
  width: 58px;
  height: 58px;
  max-width: 58px;
  min-width: 58px;
  border-radius: 14px;
  margin: 0 auto 4px;
  object-fit: cover;
  box-shadow: 0 4px 16px rgba(255, 77, 154, 0.25);
}

.bkc-ad-cell figcaption {
  font-size: 0.68rem;
  color: var(--bkc-muted);
  line-height: 1.3;
}

/* Header */
.bkc-header {
  position: sticky;
  top: 0;
  z-index: 900;
  backdrop-filter: blur(14px);
  background: var(--bkc-glass);
  border-bottom: 1px solid var(--bkc-line);
}

.bkc-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--bkc-header-h);
  gap: 16px;
}

.bkc-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--bkc-text);
  font-weight: 700;
  font-size: 1.05rem;
}

.bkc-brand img {
  width: 38px;
  height: 38px;
  border-radius: 10px;
}

.bkc-nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--bkc-line);
  color: var(--bkc-text);
  border-radius: 10px;
  padding: 8px 12px;
  cursor: pointer;
}

.bkc-nav-panel ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 6px 22px;
  flex-wrap: wrap;
}

.bkc-nav-panel a {
  color: var(--bkc-muted);
  font-size: 0.92rem;
  font-weight: 500;
}

.bkc-nav-panel a:hover,
.bkc-nav-panel a[aria-current="page"] {
  color: var(--bkc-magenta);
}

/* Sticky download bar */
#bkc-dl-bar {
  position: fixed;
  top: var(--bkc-header-h);
  left: 0;
  right: 0;
  z-index: 850;
  background: rgba(15, 14, 26, 0.94);
  border-bottom: 1px solid var(--bkc-line);
  padding: 8px 12px;
  transform: translateY(-110%);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

#bkc-dl-bar.bkc-dl-visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

#bkc-dl-grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 6px 8px;
  max-width: 960px;
  margin: 0 auto;
}

.bkc-dl-cell a {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  color: var(--bkc-muted);
  font-size: 0.62rem;
}

.bkc-dl-cell img {
  width: 42px;
  height: 42px;
  max-width: 42px;
  min-width: 42px;
  border-radius: 10px;
  object-fit: cover;
}

@media (max-width: 768px) {
  #bkc-dl-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  .bkc-nav-toggle { display: block; }
  .bkc-nav-panel {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bkc-glass);
    border-bottom: 1px solid var(--bkc-line);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }
  .bkc-nav-panel.bkc-nav-open {
    max-height: 280px;
  }
  .bkc-nav-panel ul {
    flex-direction: column;
    padding: 14px 20px 18px;
  }
}

/* Hero */
.bkc-hero {
  position: relative;
  padding: 56px 0 72px;
  overflow: hidden;
}

.bkc-hero::before {
  content: "";
  position: absolute;
  inset: -20% -10%;
  background:
    radial-gradient(circle at 20% 30%, rgba(255, 77, 154, 0.22), transparent 45%),
    radial-gradient(circle at 80% 20%, rgba(66, 240, 220, 0.18), transparent 40%),
    radial-gradient(circle at 60% 80%, rgba(139, 108, 255, 0.15), transparent 50%);
  animation: bkc-shift 12s ease-in-out infinite alternate;
  pointer-events: none;
}

@keyframes bkc-shift {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-3%, 2%) scale(1.05); }
}

.bkc-hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}

.bkc-hero-tag {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 77, 154, 0.2), rgba(66, 240, 220, 0.15));
  border: 1px solid var(--bkc-line);
  font-size: 0.82rem;
  color: var(--bkc-cyan);
  margin-bottom: 16px;
}

.bkc-hero-lead {
  font-size: 1.05rem;
  color: var(--bkc-muted);
  max-width: 540px;
}

.bkc-hero-visual {
  position: relative;
}

.bkc-hero-blob {
  position: absolute;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--bkc-magenta), var(--bkc-violet));
  filter: blur(60px);
  opacity: 0.35;
  top: 10%;
  right: 5%;
  animation: bkc-float 6s ease-in-out infinite;
}

@keyframes bkc-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-16px); }
}

.bkc-hero-card {
  position: relative;
  background: var(--bkc-surface);
  border: 1px solid var(--bkc-line);
  border-radius: 24px;
  padding: 20px;
  backdrop-filter: blur(10px);
}

.bkc-hero-card img {
  border-radius: 16px;
  width: 100%;
}

@media (max-width: 860px) {
  .bkc-hero-grid { grid-template-columns: 1fr; }
}

/* Sections */
.bkc-section {
  padding: 52px 0;
}

.bkc-section-alt {
  background: linear-gradient(180deg, rgba(139, 108, 255, 0.06), transparent);
}

.bkc-section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 36px;
}

.bkc-section-head p {
  color: var(--bkc-muted);
}

/* Mosaic cards */
.bkc-mosaic {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.bkc-mosaic-card {
  background: var(--bkc-surface);
  border: 1px solid var(--bkc-line);
  border-radius: var(--bkc-radius);
  padding: 22px;
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.bkc-mosaic-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 77, 154, 0.35);
}

.bkc-mosaic-card h3 {
  color: var(--bkc-peach);
}

@media (max-width: 768px) {
  .bkc-mosaic { grid-template-columns: 1fr; }
}

/* Split feature */
.bkc-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  align-items: center;
}

.bkc-split-reverse {
  direction: rtl;
}

.bkc-split-reverse > * {
  direction: ltr;
}

.bkc-shot-frame {
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--bkc-line);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
}

@media (max-width: 768px) {
  .bkc-split,
  .bkc-split-reverse {
    grid-template-columns: 1fr;
    direction: ltr;
  }
}

/* Timeline */
.bkc-timeline {
  position: relative;
  padding-left: 28px;
  border-left: 2px solid var(--bkc-line);
}

.bkc-timeline-item {
  position: relative;
  margin-bottom: 28px;
  padding-left: 8px;
}

.bkc-timeline-item::before {
  content: "";
  position: absolute;
  left: -35px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bkc-magenta);
  box-shadow: 0 0 12px rgba(255, 77, 154, 0.6);
}

/* Pill row */
.bkc-pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 16px 0;
}

.bkc-pill {
  padding: 8px 16px;
  border-radius: 999px;
  background: rgba(66, 240, 220, 0.1);
  border: 1px solid rgba(66, 240, 220, 0.25);
  font-size: 0.88rem;
  color: var(--bkc-cyan);
}

/* Text block */
.bkc-prose {
  max-width: 820px;
}

.bkc-prose-wide {
  max-width: none;
}

/* CTA band */
.bkc-cta-band {
  text-align: center;
  padding: 48px 24px;
  border-radius: 24px;
  background: linear-gradient(135deg, rgba(255, 77, 154, 0.12), rgba(139, 108, 255, 0.12));
  border: 1px solid var(--bkc-line);
}

.bkc-btn-dl {
  display: inline-block;
  margin-top: 12px;
  padding: 14px 32px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--bkc-magenta), var(--bkc-violet));
  color: #fff;
  font-weight: 600;
  font-size: 1rem;
  box-shadow: 0 8px 28px rgba(255, 77, 154, 0.35);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.bkc-btn-dl:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(255, 77, 154, 0.45);
}

/* Breadcrumb */
.bkc-crumb {
  padding: 14px 0;
  font-size: 0.85rem;
  color: var(--bkc-muted);
}

.bkc-crumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.bkc-crumb li + li::before {
  content: "›";
  margin-right: 6px;
  color: var(--bkc-violet);
}

/* Legal / inner pages */
.bkc-page-hero {
  padding: 36px 0 28px;
  border-bottom: 1px solid var(--bkc-line);
}

.bkc-legal {
  padding: 36px 0 64px;
}

.bkc-legal h2 {
  margin-top: 2em;
  color: var(--bkc-peach);
}

.bkc-legal h3 {
  margin-top: 1.5em;
  color: var(--bkc-cyan);
}

/* Footer */
.bkc-footer {
  border-top: 1px solid var(--bkc-line);
  padding: 40px 0 28px;
  background: rgba(0, 0, 0, 0.2);
}

.bkc-footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 28px;
  margin-bottom: 28px;
}

.bkc-footer h4 {
  font-size: 0.95rem;
  color: var(--bkc-peach);
  margin-bottom: 12px;
}

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

.bkc-footer li {
  margin-bottom: 8px;
}

.bkc-footer a {
  color: var(--bkc-muted);
  font-size: 0.88rem;
}

.bkc-footer-copy {
  text-align: center;
  font-size: 0.82rem;
  color: var(--bkc-muted);
  padding-top: 20px;
  border-top: 1px solid var(--bkc-line);
}

@media (max-width: 768px) {
  .bkc-footer-grid { grid-template-columns: 1fr; }
}

/* Error pages */
.bkc-error {
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 48px 20px;
}

.bkc-error-code {
  font-size: clamp(4rem, 12vw, 7rem);
  font-weight: 700;
  background: linear-gradient(135deg, var(--bkc-magenta), var(--bkc-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 12px;
}

/* Reveal animation */
.bkc-reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.bkc-reveal.bkc-inview {
  opacity: 1;
  transform: translateY(0);
}

/* Link grid */
.bkc-link-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.bkc-link-card {
  padding: 18px;
  border-radius: var(--bkc-radius);
  background: var(--bkc-surface);
  border: 1px solid var(--bkc-line);
  text-align: center;
}

@media (max-width: 600px) {
  .bkc-link-grid { grid-template-columns: 1fr; }
}