* {
  box-sizing: border-box;
}

:root {
  --bg: #f3efe7;
  --panel: rgba(255, 255, 255, 0.88);
  --panel-strong: rgba(255, 255, 255, 0.96);
  --text: #161616;
  --muted: rgba(22, 22, 22, 0.6);
  --line: rgba(22, 22, 22, 0.08);
  --button: #161616;
  --button-text: #ffffff;
  --dot: #cfc8bc;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: Arial, Helvetica, sans-serif;
  background: var(--bg);
  color: var(--text);
}

body {
  overflow: hidden;
}

.app {
  height: 100vh;
  display: grid;
  grid-template-rows: 96px 1fr 116px;
  background:
    radial-gradient(circle at top, rgba(255,255,255,0.75), transparent 45%),
    linear-gradient(180deg, #f7f3ec 0%, #efe8dc 100%);
}

/* Top */
.topbar {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18px 20px;
  border-bottom: 1px solid rgba(0,0,0,0.08);
  background: rgb(253,238,13);
}

.logo-wrap {
  padding: 6px 14px;
}

.logo {
  display: block;
  max-height: 100px;
  max-width: 260px;
  object-fit: contain;
}

/* Slide area */
.slider {
  position: relative;
  overflow: hidden;
  padding: 24px;
}

.slide {
  position: absolute;
  inset: 0;
  display: none;
  padding: 24px;
}

.slide.is-active {
  display: flex;
  align-items: center;
  justify-content: center;
}

.slide-inner {
  width: 100%;
  max-width: 760px;
  min-height: min(66vh, 920px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 42px 36px;
  border-radius: 28px;
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.55);
  box-shadow:
    0 14px 40px rgba(0, 0, 0, 0.08),
    inset 0 1px 0 rgba(255,255,255,0.5);
}

.slide-kicker {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 18px;
}

h1 {
  margin: 0 0 18px;
  font-size: clamp(46px, 5vw, 64px);
  line-height: 1.02;
}

p {
  margin: 0;
  max-width: 16ch;
  font-size: clamp(24px, 3vw, 32px);
  line-height: 1.35;
  color: rgba(22, 22, 22, 0.78);
}

/* Bottom controls */
.controls {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 18px;
  padding: 18px 24px;
  background: var(--panel-strong);
  border-top: 1px solid var(--line);
  backdrop-filter: blur(8px);
}

.controls .nav-button:first-child {
  justify-self: start;
}

.controls .nav-button:last-child {
  justify-self: end;
}

.nav-button {
  min-width: 156px;
  min-height: 64px;
  padding: 0 22px;
  border: 0;
  border-radius: 16px;
  font-size: 24px;
  font-weight: 700;
  background: var(--button);
  color: var(--button-text);
  cursor: pointer;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
}

.nav-button:active {
  transform: translateY(1px);
}

.nav-button:disabled {
  opacity: 0.35;
  cursor: default;
  box-shadow: none;
}

.dots {
  display: flex;
  gap: 14px;
  justify-content: center;
  align-items: center;
}

.dot {
  width: 18px;
  height: 18px;
  border: 0;
  border-radius: 50%;
  background: var(--dot);
  cursor: pointer;
}

.dot.is-active {
  background: var(--text);
  transform: scale(1.08);
}

.lang-switch {
  position: absolute;
  right: 20px;
  display: flex;
  gap: 8px;
}

.lang-btn {
  min-width: 54px;
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid rgba(0,0,0,0.12);
  border-radius: 999px;
  background: rgba(255,255,255,0.35);
  color: #111;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
}

.lang-btn.is-active {
  background: #111;
  color: #fff;
  border-color: #111;
}

.poster-slide {
  padding: 18px;
}

.poster-image {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
  border-radius: 18px;
  box-shadow: 0 14px 30px rgba(0,0,0,0.14);
}

.book-slide {
  padding: 28px 28px 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: 16px;
}

.book-heading {
  width: 100%;
  text-align: center;
}

.book-heading .slide-kicker {
  margin-bottom: 10px;
}

.book-heading h1 {
  margin: 0;
}

.book-author {
  width: 100%;
  display: block;
  margin: 10px auto 0;
  font-size: 22px;
  line-height: 1.2;
  font-weight: 700;
  color: rgba(22,22,22,0.72);
  text-align: center;
}

.book-cover-wrap {
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.book-cover {
  display: block;
  max-height: 250px;
  width: auto;
  max-width: 100%;
  object-fit: contain;
  border-radius: 14px;
  box-shadow: 0 14px 28px rgba(0,0,0,0.14);
}

.book-text-wrap {
  width: 100%;
  max-width: 520px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  text-align: center;
}

.book-description {
  margin: 0;
  max-width: 40ch;
  font-size: 22px;
  line-height: 1.35;
  color: rgba(22,22,22,0.82);
  text-align: center;
}

.book-meta {
  margin: 0;
  max-width: 34ch;
  font-size: 15px;
  line-height: 1.45;
  color: rgba(22,22,22,0.58);
  text-align: center;
}

.book-qr-wrap {
  margin-top: 6px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.book-qr {
  display: block;
  width: 112px;
  height: 112px;
  object-fit: contain;
  border-radius: 10px;
  background: #fff;
  padding: 8px;
  box-shadow: 0 10px 22px rgba(0,0,0,0.12);
}

.book-qr-text {
  margin: 0;
  max-width: 22ch;
  font-size: 15px;
  line-height: 1.3;
  color: rgba(22,22,22,0.68);
  text-align: center;
}