/* Reset and root */
:root {
  --top-band-bg: #0b1375;
  --top-band-text: #ffffff;

  --banner-bg: #12C3F4;
  --banner-text: #ffffff;

  --book-band-bg: #f0f0ff;
  --book-band-text: #ffffff;

  --thin-strip-bg: #12C3F4;

  --footer-band-bg: #0b1375;
  --footer-text: #ffffff;

  --btn-bg: #0b1375;
  --btn-text: #ffffff;
  --btn-border: #ffffff;

  --body-bg: #fafafa;
  --body-text: #222;
  --max-width: 100vw;
  --radius: 14px;
  --shadow-soft: 7px 7px 18px rgba(0, 0, 0, 0.18);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  width: 100%;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--body-bg);
  color: var(--body-text);
  min-height: 100vh;
  overflow-x: hidden;
}

main {
  display: flex;
  flex-direction: column;
  height: 100vh;
  width: 100%;
}

/* top band stuff */

.top-band {
  background: var(--top-band-bg);
  color: var(--top-band-text);
  height: 25vh;
  padding: 8px 80px;
}

.top-band-inner {
  display: flex;
  flex-direction: column;
  gap: 30px;
  height: 100%;
}

.titles {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
}

.main-title {
  font-size: clamp(1.9rem, 3vw, 2.6rem);
  font-weight: 700;
}

.subtitle {
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 20px;
}

.nav-buttons {
  width: 100%;
  display: grid;
  gap: 14px;
  align-self: stretch;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.nav-button {
  padding: 10px 20px;
  background: var(--btn-bg);
  color: var(--btn-text);
  border: 3px solid var(--btn-border);
  border-radius: var(--radius);
  font-size: 18px;
  cursor: pointer;
  text-align: left;
  white-space: nowrap;
  transition: transform 0.15s ease,
              box-shadow 0.15s ease,
              background 0.15s ease;
}

.nav-button:hover {
  transform: translateY(-1.28px);
  box-shadow: var(--shadow-soft);
  background: rgba(255, 255, 255, 0.08);
}

.purchase-link {
  display: inline-flex;
  align-items: center;
  gap: 5.6px;
  padding: 4px 12px;
  border-radius: 50px;
  border: 0.08rem solid #ffffff;
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
  text-decoration: none;
  font-size: 14.5px;
  font-weight: 500;
  white-space: nowrap;
  transition: background 0.15s ease,
              transform 0.15s ease,
              box-shadow 0.15s ease;
}

.purchase-link:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateY(-1px);
  box-shadow: var(--shadow-soft);
}

.purchase-link-icon {
  font-size: 1rem;
  line-height: 1;
}

.banner {
  background: var(--thin-strip-bg);
  height: 1vh;
  width: 100%;
}

/* mid-band stuff */

.book-band {
  background: var(--book-band-bg);
  color: var(--book-band-text);
  height: 58vh;
  display: flex;
}

.book-band-inner {
  max-width: var(--max-width);
  margin: 0 100px;
  height: 100%;
  display: flex;
  align-items: stretch;
  gap: 2%;
}

.book-info {
  color: #222222;
  background: transparent;
  border-radius: 0;
  box-shadow: none;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}

.book-info-left {
  flex: 0 0 23%;
  order: 1;
  text-align: left;
  margin-top: 25px;
}

.book-info-right {
  flex: 0 0 23%;
  order: 3;
  text-align: left;
  margin-top: 25px;
}

.book-info-title {
  font-size: clamp(1.05rem, 1.4vw, 1.2rem);
  font-weight: 600;
  margin-bottom: 0.35rem;
  text-align: justify;
  text-justify: inter-word;
}

.book-info-body {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  align-items: flex-start;
}

.book-info-text {
  flex: 1;
  font-size: 0.95rem;
  line-height: 1.55;
  text-align: justify;
  text-justify: inter-word;
}

.book-info-main-btn {
  display: inline-block;
  margin-bottom: 1.5rem;
  padding: 1rem 2.5rem;
  border-radius: 999px;
  border: 0.08rem solid var(--btn-border);
  background: var(--btn-bg);
  color: var(--btn-text);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition:
    background 0.15s ease,
    transform 0.15s ease,
    box-shadow 0.15s ease;
}

.book-info-main-btn:hover {
  transform: translateY(-0.06rem);
  box-shadow: var(--shadow-soft);
  background: rgba(17, 50, 201, 0.8);
}

.copy-citation-btn.copy-text-btn {
  align-self: flex-start;
  padding: 0.4rem 0.9rem;
  border-radius: 999px;
  border: 0.08rem solid var(--btn-border);
  background: var(--btn-bg);
  color: var(--btn-text);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition:
    background 0.15s ease,
    transform 0.15s ease,
    box-shadow 0.15s ease;
}

.copy-citation-btn.copy-text-btn:hover {
  transform: translateY(-0.06rem);
  box-shadow: var(--shadow-soft);
  background: rgba(17, 50, 201, 0.8);
}

.book-covers {
  flex: 0 0 50%;
  order: 2;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1%;
}

.book-cover {
  flex: 1;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.book-cover img {
  height: 95%;
  max-height: 100%;
  border-radius: 0.4rem;
  box-shadow: var(--shadow-soft);
  object-fit: contain;
  cursor: pointer;
}

.book-cover:hover img {
  transform: translateY(-4px) scale(1.02);
  box-shadow: 0 10px 25px rgba(0,0,0,0.35);
}

.book-cover.front img {
  transform: rotate(-2deg);
}

.book-cover.back img {
  transform: rotate(2deg);
}

/* footer */

.thin-strip {
  background: var(--thin-strip-bg);
  height: 1vh;
  width: 100%;
}

.footer-band {
  background: var(--footer-band-bg);
  color: var(--footer-text);
  height: 15vh;
  padding: 0.5rem 4vw;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  align-items: center;
  text-align: center;
  height: 100%;
  justify-content: center;
}

.footer-copy {
  font-size: 1.2rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
  justify-content: center;
  font-size: 1.2rem;
}

.footer-link {
  text-decoration: none;
  color: var(--footer-text);
  font-weight: 500;
  position: relative;
  padding-bottom: 0.1rem;
}

.footer-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0%;
  height: 0.08rem;
  background: var(--footer-text);
  transition: width 0.18s ease;
}

.footer-link:hover::after {
  width: 100%;
}

/* ============================
   MOBILE HUB (hidden on desktop)
   ============================ */
/* ============================
   MOBILE HUB (hidden on desktop)
   ============================ */
.mobile-hub {
  display: none;
}

.mobile-hub-panel {
  margin-top: 0.8rem;
  padding: 0.9rem 1rem;
  border-radius: var(--radius);
  background: #f4f4ff;
  box-shadow: var(--shadow-soft);
}

.mobile-hub-purchase {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  margin-bottom: 1rem;
  padding: 0.5rem 0.8rem;
  border-radius: 999px;
  border: 0.08rem solid var(--btn-border);
  background: rgba(11, 19, 117, 0.92);
  color: #ffffff;
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
}

.mobile-hub-group {
  margin-top: 0.75rem;
}

.mobile-hub-group h3 {
  margin-bottom: 0.35rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: #222222;
}

.mobile-hub-link {
  width: 100%;
  text-align: left;
  margin-bottom: 0.35rem;
  padding: 0.45rem 0.7rem;
  border-radius: 0.5rem;
  border: 1px solid rgba(11, 19, 117, 0.2);
  background: #ffffff;
  color: #222222;
  font-size: 0.9rem;
  cursor: pointer;
}


.mobile-hub-purchase {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  margin-bottom: 1rem;
  padding: 0.5rem 0.8rem;
  border-radius: 999px;
  border: 0.08rem solid var(--btn-border);
  background: rgba(11, 19, 117, 0.92);
  color: #ffffff;
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
}

.mobile-hub-group {
  margin-top: 0.75rem;
}

.mobile-hub-group h3 {
  margin-bottom: 0.35rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: #222222;
}

.mobile-hub-link {
  width: 100%;
  text-align: left;
  margin-bottom: 0.35rem;
  padding: 0.45rem 0.7rem;
  border-radius: 0.5rem;
  border: 1px solid rgba(11, 19, 117, 0.2);
  background: #ffffff;
  color: #222222;
  font-size: 0.9rem;
  cursor: pointer;
}

/*768px*/

@media (max-width: 1500px) {
  .top-band {
    height: auto;
    padding: 0.75rem 1rem;
  }

  .top-band-inner {
    gap: 0.75rem;
  }

  .nav-buttons {
    display: none;
  }

  .mobile-hub {
    display: block;
    padding: 0;
  }

  .mobile-hub-panel {
    margin: 0.8rem auto 0;
    max-width: 520px;
    width: 90vw;
  }

  .mobile-hub-link {
    margin-left: 0;
  }

  /* hide heavy sections on mobile, but keep footer */
  .banner,
  .book-band,
  .thin-strip {
    display: none;
  }
}

@media (max-width: 768px) {
  .footer-band {
    height: auto;
    padding: 0.75rem 1rem 1.25rem;
  }

  .footer-links {
    display: none;
  }

  .footer-inner {
    align-items: center;
    text-align: center;
  }
}