:root {
  color-scheme: dark;
  --black: #030405;
  --ink: #090a0d;
  --panel: #17191f;
  --line: #353844;
  --paper: #e9e2d2;
  --muted: #aaa69c;
  --green: #a6f23d;
  --violet: #9a67ff;
  --orange: #ff7a3d;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

* { box-sizing: border-box; }

html, body { height: 100%; margin: 0; overflow: hidden; background: var(--black); }

body {
  color: #f8f7f2;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

button, a { font: inherit; }

button { color: inherit; }

.app {
  min-height: 100dvh;
  display: grid;
  grid-template-rows: calc(58px + var(--safe-top)) minmax(0, 1fr) calc(70px + var(--safe-bottom)) 3px;
  background: radial-gradient(circle at 50% 48%, #1a1721 0, var(--ink) 40%, var(--black) 78%);
}

.topbar {
  padding: var(--safe-top) clamp(18px, 3.3vw, 56px) 0;
  height: calc(58px + var(--safe-top));
  display: grid;
  grid-template-columns: 120px 1fr auto;
  align-items: center;
  gap: 24px;
  background: rgba(3, 4, 5, .96);
  border-bottom: 1px solid rgba(255,255,255,.08);
  z-index: 10;
}

.wordmark {
  border: 0;
  padding: 0;
  background: transparent;
  color: var(--green);
  font-size: 18px;
  font-weight: 900;
  letter-spacing: -.03em;
  text-align: left;
  cursor: pointer;
}

.chapters { display: flex; justify-content: center; align-items: stretch; height: 100%; gap: clamp(20px, 3.2vw, 56px); }

.chapters button {
  position: relative;
  border: 0;
  background: transparent;
  color: #8f8d88;
  text-transform: uppercase;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .09em;
  cursor: pointer;
  transition: color 160ms ease;
}

.chapters button:hover, .chapters button:focus-visible, .chapters button.active { color: var(--green); }
.chapters button.active::after { content: ""; position: absolute; left: 18%; right: 18%; bottom: 0; height: 2px; background: var(--green); }

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

.utility, .download {
  border: 1px solid var(--line);
  border-radius: 7px;
  background: rgba(23,25,31,.8);
  color: #c9c6bd;
  padding: 9px 12px;
  text-decoration: none;
  text-transform: uppercase;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .06em;
  cursor: pointer;
  transition: border-color 160ms ease, color 160ms ease, background 160ms ease;
}

.utility:hover, .utility:focus-visible { border-color: var(--violet); color: #fff; }
.download { background: var(--green); border-color: var(--green); color: var(--black); }
.download:hover, .download:focus-visible { background: #bcff5a; }

.stage {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 0;
  padding: 18px clamp(64px, 7vw, 112px);
  isolation: isolate;
}

.ambient {
  position: absolute;
  inset: 8% 12%;
  z-index: -1;
  background: radial-gradient(circle at 50% 50%, rgba(154,103,255,.18), transparent 62%);
  filter: blur(56px);
  transition: background 240ms ease;
}

.slide-frame {
  position: relative;
  margin: 0;
  width: min(100%, calc((100dvh - 149px) * 16 / 9));
  aspect-ratio: 16 / 9;
  background: #000;
  box-shadow: 0 34px 100px rgba(0,0,0,.62), 0 0 0 1px rgba(255,255,255,.08);
  overflow: hidden;
}

.slide-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  user-select: none;
  opacity: 1;
  transform: scale(1);
  transition: opacity 150ms ease, transform 240ms cubic-bezier(.2,.8,.2,1);
}

.slide-frame img.changing { opacity: .2; transform: scale(.992); }

.loading { position: absolute; left: 0; right: 100%; bottom: 0; height: 2px; background: var(--green); transition: right 180ms ease; }
.loading.active { right: 0; }

.edge {
  position: absolute;
  top: 50%;
  translate: 0 -50%;
  width: 54px;
  height: 104px;
  border: 0;
  background: transparent;
  color: rgba(255,255,255,.38);
  font-size: 28px;
  cursor: pointer;
  transition: color 150ms ease, transform 150ms ease;
}
.edge:hover, .edge:focus-visible { color: var(--green); transform: scale(1.08); }
.edge:disabled { opacity: .12; cursor: default; }
.edge-left { left: clamp(4px, 1.5vw, 26px); }
.edge-right { right: clamp(4px, 1.5vw, 26px); }

.controls {
  min-height: calc(70px + var(--safe-bottom));
  padding: 0 clamp(18px, 3.3vw, 56px) var(--safe-bottom);
  display: grid;
  grid-template-columns: 100px 1fr auto;
  align-items: center;
  gap: 22px;
  background: var(--black);
  border-top: 1px solid rgba(255,255,255,.08);
}

.counter { display: flex; gap: 8px; color: #77746c; font-size: 13px; font-variant-numeric: tabular-nums; }
.counter #currentNumber { color: var(--green); font-weight: 900; }
.slash { color: var(--line); }
.meta { min-width: 0; }
.title { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 15px; font-weight: 800; text-transform: uppercase; letter-spacing: .035em; }
.hint { margin-top: 4px; color: #77746c; font-size: 10px; }
.transport { display: none; gap: 8px; }
.transport button { width: 46px; height: 38px; border: 1px solid var(--line); border-radius: 7px; background: var(--panel); font-size: 20px; }
.progress { background: #14151a; }
.progress > div { width: 6.25%; height: 100%; background: linear-gradient(90deg, var(--violet), var(--green)); transition: width 220ms ease; }

.grid-dialog {
  width: min(1180px, calc(100vw - 36px));
  height: min(760px, calc(100dvh - 36px));
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(9,10,13,.98);
  color: #fff;
  box-shadow: 0 40px 130px rgba(0,0,0,.82);
}
.grid-dialog::backdrop { background: rgba(0,0,0,.82); backdrop-filter: blur(8px); }
.grid-head { position: sticky; top: 0; z-index: 2; display: flex; align-items: center; justify-content: space-between; padding: 24px 28px; background: rgba(9,10,13,.95); border-bottom: 1px solid var(--line); }
.grid-title { font-size: 28px; font-weight: 900; text-transform: uppercase; letter-spacing: -.02em; }
.grid-subtitle { margin-top: 4px; color: var(--muted); font-size: 13px; }
.grid-head button { border: 1px solid var(--line); border-radius: 7px; background: var(--panel); color: #fff; padding: 10px 14px; cursor: pointer; }
.slide-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; padding: 24px 28px 32px; }
.thumb { display: block; padding: 0; border: 1px solid var(--line); background: #000; color: #fff; cursor: pointer; text-align: left; transition: border-color 150ms ease, transform 150ms ease; }
.thumb:hover, .thumb:focus-visible, .thumb.active { border-color: var(--green); transform: translateY(-2px); }
.thumb img { display: block; width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.thumb span { display: flex; gap: 8px; padding: 9px 10px; color: #aaa69c; font-size: 10px; text-transform: uppercase; }
.thumb b { color: var(--green); }

.sr-only { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

:focus-visible { outline: 2px solid var(--violet); outline-offset: 3px; }

@media (max-width: 940px) {
  .topbar { grid-template-columns: 72px 1fr; }
  .chapters { display: none; }
  .actions { justify-self: end; }
  .utility { display: none; }
  .stage { padding-inline: 16px; }
  .edge { display: none; }
  .transport { display: flex; }
  .hint { display: none; }
  .slide-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
  .app { grid-template-rows: calc(54px + var(--safe-top)) minmax(0, 1fr) calc(64px + var(--safe-bottom)) 3px; }
  .topbar { height: calc(54px + var(--safe-top)); padding-inline: 15px; gap: 12px; }
  .download { padding: 8px 10px; font-size: 9px; }
  .stage { padding: 12px 8px; }
  .slide-frame { width: 100%; }
  .controls { grid-template-columns: 55px 1fr auto; padding-inline: 15px; gap: 10px; }
  .title { font-size: 11px; }
  .slide-grid { grid-template-columns: 1fr; padding-inline: 16px; }
}

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