/* ── PAGE HEADER ────────────────────────────── */
.zb-header {
  padding: calc(var(--nav-h) + 60px) 24px 20px;
  text-align: center;
  background: #fff;
}
.zb-header__title {
  font-size: 48px;
  font-weight: 700;
  color: var(--text);
}

/* ── BOOK SECTIONS ──────────────────────────── */
.zb-book {
  padding: 60px 0;
  background: #fff;
}
.zb-book__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 80px;
}
.zb-book__text {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
}
.zb-book__title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--text);
  margin: 0;
}
.zb-book__desc {
  font-size: 15px;
  font-weight: 500;
  color: var(--muted);
  line-height: 1.6;
  max-width: 420px;
  margin: 0;
}

/* ── COVER ──────────────────────────────────── */
.zb-book__cover {
  flex: 0 0 220px;
  position: relative;
  cursor: pointer;
}
.zb-book__cover img {
  width: 220px;
  height: auto;
  display: block;
  border-radius: 8px;
  box-shadow: 0 8px 32px rgba(0,0,0,.14);
  transition: transform .25s ease, box-shadow .25s ease;
}
.zb-book__cover:not(.zb-book__cover--locked):hover img {
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 16px 40px rgba(0,0,0,.2);
}
.zb-book__cover--locked {
  cursor: default;
  opacity: .7;
}
.zb-book__cover-hint {
  position: absolute;
  bottom: -12px;
  left: 50%;
  transform: translateX(-50%) translateY(4px);
  background: var(--orange);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 5px 14px;
  border-radius: 999px;
  display: flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
  opacity: 0;
  transition: opacity .2s, transform .2s;
  pointer-events: none;
}
.zb-book__cover:hover .zb-book__cover-hint {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.zb-book__cover-hint--soon { background: var(--muted); }

.btn--red { background: var(--red); color: #fff; }
.btn[disabled] { opacity: .55; cursor: not-allowed; }
.btn[disabled]:hover { opacity: .55; transform: none; }

/* ── PDF MODAL ──────────────────────────────── */
.pdf-modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
}
.pdf-modal.open { display: block; }

.pdf-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10,10,20,.7);
  backdrop-filter: blur(8px);
}
.pdf-modal__shell {
  position: absolute;
  inset: 40px;
  z-index: 1;
  display: flex;
  flex-direction: column;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0,0,0,.55);
}

/* top bar */
.pdf-modal__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #1a1a2e;
  padding: 0 20px;
  height: 48px;
  flex-shrink: 0;
}
.pdf-modal__title {
  font-size: 13px;
  font-weight: 700;
  color: rgba(255,255,255,.75);
  letter-spacing: .02em;
}
.pdf-modal__close {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,.1);
  border: none;
  color: rgba(255,255,255,.8);
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: 999px;
  cursor: pointer;
  transition: background .2s;
}
.pdf-modal__close:hover { background: rgba(255,255,255,.2); }

/* iframe fills the rest */
.pdf-modal__frame {
  flex: 1;
  width: 100%;
  border: none;
  display: block;
  background: #525659;
}

/* ── RESPONSIVE ─────────────────────────────── */
@media (max-width: 768px) {
  .zb-header__title { font-size: 36px; }
  .zb-book__inner { flex-direction: column; gap: 40px; align-items: flex-start; }
  .zb-book__cover { flex: none; align-self: center; }
  .pdf-modal__spread { flex-direction: column; gap: 0; }
  .pdf-modal__page { max-height: 45vh; width: 80vw; height: auto; }
}