:root {
  color-scheme: light;
  --kb-bg: #f7f7f8;
  --kb-bg-soft: #fbfafb;
  --kb-surface: #ffffff;
  --kb-surface-soft: #fff7f8;
  --kb-text: #18181b;
  --kb-heading: #09090b;
  --kb-muted: #71717a;
  --kb-line: rgba(24, 24, 27, .09);
  --kb-line-strong: rgba(24, 24, 27, .14);
  --kb-primary: #e11d48;
  --kb-primary-hover: #be123c;
  --kb-primary-dark: #881337;
  --kb-accent: #f97316;
  --kb-success: #16a34a;
  --kb-danger: #dc2626;
  --kb-shadow-xs: 0 1px 2px rgba(15, 23, 42, .04);
  --kb-shadow-sm: 0 8px 24px rgba(15, 23, 42, .06);
  --kb-shadow-md: 0 18px 50px rgba(15, 23, 42, .09);
  --kb-shadow-lg: 0 26px 80px rgba(15, 23, 42, .14);
  --kb-radius-sm: 12px;
  --kb-radius-md: 18px;
  --kb-radius-lg: 24px;
  --kb-radius-xl: 32px;
  --kb-container: min(1180px, calc(100% - 32px));
  --kb-nav-height: 72px;
  --kb-transition: 180ms cubic-bezier(.2, .8, .2, 1);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  min-width: 320px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--kb-text);
  background:
    radial-gradient(circle at 12% -10%, rgba(225, 29, 72, .10), transparent 34%),
    radial-gradient(circle at 88% 0%, rgba(249, 115, 22, .07), transparent 30%),
    var(--kb-bg);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
img, svg, video, iframe { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }
button, select { cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: .58; }
::selection { color: #fff; background: var(--kb-primary); }

:focus-visible {
  outline: 3px solid rgba(225, 29, 72, .28);
  outline-offset: 3px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 60;
  border-bottom: 1px solid rgba(24, 24, 27, .07);
  background: rgba(255, 255, 255, .82);
  -webkit-backdrop-filter: blur(18px) saturate(145%);
  backdrop-filter: blur(18px) saturate(145%);
}
.topbar-inner {
  width: var(--kb-container);
  min-height: var(--kb-nav-height);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  position: relative;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  min-width: max-content;
  color: var(--kb-heading);
  font-weight: 850;
  letter-spacing: -.025em;
}
.brand-mark {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  flex: none;
  color: #fff;
  border-radius: 14px;
  background: linear-gradient(145deg, var(--kb-primary), var(--kb-primary-dark));
  box-shadow: 0 9px 22px rgba(190, 18, 60, .24);
  transform: rotate(-2deg);
}
.topbar-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 4px;
}
.topbar-nav a {
  min-height: 42px;
  padding: 0 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 13px;
  color: #52525b;
  font-size: .91rem;
  font-weight: 700;
  transition: color var(--kb-transition), background var(--kb-transition), transform var(--kb-transition);
}
.topbar-nav a:hover { color: var(--kb-heading); background: #f4f4f5; }
.topbar-nav a.active { color: var(--kb-primary-hover); background: var(--kb-surface-soft); }
.nav-toggle {
  width: 42px;
  height: 42px;
  display: none;
  place-items: center;
  padding: 0;
  color: var(--kb-heading);
  border: 1px solid var(--kb-line);
  border-radius: 13px;
  background: var(--kb-surface);
  box-shadow: var(--kb-shadow-xs);
}

.kb-button,
.ghost-btn,
.primary-btn,
.action-btn,
.card-btn {
  transition:
    transform var(--kb-transition),
    box-shadow var(--kb-transition),
    background var(--kb-transition),
    border-color var(--kb-transition),
    color var(--kb-transition);
}
@media (hover: hover) {
  .kb-button:hover,
  .ghost-btn:hover,
  .primary-btn:hover,
  .action-btn:hover,
  .card-btn:hover { transform: translateY(-1px); }
}

.toast-stack {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 140;
  display: grid;
  gap: 10px;
  pointer-events: none;
}
.toast-item {
  width: min(360px, calc(100vw - 36px));
  padding: 13px 16px;
  color: #fff;
  border: 1px solid rgba(255, 255, 255, .09);
  border-radius: 15px;
  background: rgba(24, 24, 27, .94);
  box-shadow: var(--kb-shadow-lg);
  font-size: .9rem;
  font-weight: 650;
  line-height: 1.5;
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  animation: kbToastIn .22s ease both;
}
@keyframes kbToastIn {
  from { opacity: 0; transform: translateY(8px) scale(.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.download-overlay {
  position: fixed;
  inset: 0;
  z-index: 150;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(9, 9, 11, .58);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}
.download-dialog {
  width: min(100%, 470px);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, .8);
  border-radius: 26px;
  background: #fff;
  box-shadow: var(--kb-shadow-lg);
  animation: kbDialogIn .2s ease both;
}
@keyframes kbDialogIn {
  from { opacity: 0; transform: translateY(10px) scale(.985); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
.download-head, .download-body { padding: 18px 20px; }
.download-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  border-bottom: 1px solid var(--kb-line);
}
.download-sub { margin-top: 4px; color: var(--kb-muted); font-size: .9rem; }
.download-close {
  width: 40px;
  height: 40px;
  flex: none;
  border: 1px solid var(--kb-line);
  border-radius: 13px;
  background: #fafafa;
}
.download-info-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 12px;
  color: var(--kb-muted);
  font-size: .9rem;
}
.download-info-row strong { max-width: 60%; color: var(--kb-text); text-align: right; word-break: break-word; }
.download-progress-track { width: 100%; height: 10px; overflow: hidden; border-radius: 999px; background: #e4e4e7; }
.download-progress-bar {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--kb-primary), var(--kb-accent));
  transition: width .2s ease;
}
.download-progress-meta { display: flex; justify-content: space-between; gap: 14px; margin-top: 10px; font-size: .88rem; font-weight: 750; }
.download-overlay.is-done .download-progress-bar { background: linear-gradient(90deg, #16a34a, #22c55e); }
.download-overlay.is-error .download-progress-bar { width: 100%; background: linear-gradient(90deg, #dc2626, #ef4444); }

@media (max-width: 760px) {
  :root { --kb-container: min(100% - 20px, 1180px); --kb-nav-height: 64px; }
  .nav-toggle { display: grid; }
  .topbar-nav {
    position: absolute;
    top: calc(100% + 9px);
    left: 0;
    right: 0;
    display: none;
    align-items: stretch;
    padding: 9px;
    border: 1px solid var(--kb-line);
    border-radius: 18px;
    background: rgba(255, 255, 255, .98);
    box-shadow: var(--kb-shadow-md);
  }
  .topbar-nav.open { display: grid; animation: kbMenuIn .18s ease both; }
  .topbar-nav a { width: 100%; min-height: 44px; justify-content: flex-start; }
  @keyframes kbMenuIn { from { opacity: 0; transform: translateY(-5px); } to { opacity: 1; transform: translateY(0); } }
  .toast-stack { right: 10px; bottom: 10px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
}

/* v4.0.4 — navigasi fleksibel untuk root, subfolder, desktop, dan mobile. */
.topbar-nav a i { width: 17px; flex: none; text-align: center; color: var(--kb-muted); }
.topbar-nav a.active i, .topbar-nav a:hover i { color: currentColor; }
.nav-backdrop {
  position: fixed;
  inset: var(--kb-nav-height) 0 0;
  z-index: 54;
  width: 100%;
  height: auto;
  padding: 0;
  border: 0;
  background: rgba(9, 9, 11, .38);
  -webkit-backdrop-filter: blur(3px);
  backdrop-filter: blur(3px);
}
.nav-backdrop[hidden] { display: none; }
body.nav-open { overflow: hidden; }

@media (min-width: 761px) {
  .topbar-nav a i { display: none; }
}

@media (max-width: 760px) {
  .topbar-inner { min-width: 0; }
  .brand { min-width: 0; }
  .brand > span:last-child { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .topbar-nav {
    position: fixed;
    top: calc(var(--kb-nav-height) + 8px);
    left: max(10px, env(safe-area-inset-left));
    right: max(10px, env(safe-area-inset-right));
    z-index: 70;
    max-height: calc(100dvh - var(--kb-nav-height) - 24px - env(safe-area-inset-bottom));
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: 10px;
    border-radius: 20px;
  }
  .topbar-nav.open { display: grid; grid-template-columns: 1fr; gap: 4px; }
  .topbar-nav a {
    min-width: 0;
    padding: 0 14px;
    gap: 11px;
    border-radius: 13px;
  }
  .topbar-nav a.active { box-shadow: inset 3px 0 0 var(--kb-primary); }
  .nav-toggle { position: relative; z-index: 72; flex: none; }
}

/* v4.0.5: navigasi fleksibel pada tablet, layar sempit, dan tinggi viewport kecil. */
@media (min-width: 761px) and (max-width: 1040px) {
  .topbar-inner { gap: 10px; }
  .topbar-nav {
    min-width: 0;
    overflow-x: auto;
    overscroll-behavior-inline: contain;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }
  .topbar-nav::-webkit-scrollbar { display: none; }
  .topbar-nav a { flex: 0 0 auto; padding-inline: 11px; }
}
@media (max-width: 760px) {
  .topbar-nav {
    max-height: calc(100dvh - var(--kb-nav-height) - 24px);
    overflow-y: auto;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
  }
  body.nav-open { overflow: hidden; touch-action: none; }
}

/* v4.1.0 — transisi lintas halaman yang halus, tetap menghormati reduced motion. */
@view-transition { navigation: auto; }
::view-transition-old(root) { animation: kb-page-out .18s ease both; }
::view-transition-new(root) { animation: kb-page-in .24s ease both; }
@keyframes kb-page-out { to { opacity: 0; transform: translateY(-4px) scale(.995); } }
@keyframes kb-page-in { from { opacity: 0; transform: translateY(7px) scale(.995); } }
html.page-leaving body { opacity: .72; transform: translateY(-2px); }
body { transition: opacity .16s ease, transform .16s ease; }
@media (prefers-reduced-motion: reduce) {
  ::view-transition-old(root), ::view-transition-new(root) { animation: none; }
  html.page-leaving body { opacity: 1; transform: none; }
}