:root {
  --bg-deep-navy: #03153f;
  --bg-navy-soft: #0b1f57;
  --teal-dark: #0f4e62;
  --teal-border: #2e8a89;
  --teal-glow: rgba(76, 235, 197, 0.45);
  --text-main: #f5fbff;
  --text-muted: #d8e5ff;
}

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

html,
body {
  height: 100%;
}

body {
  overflow: hidden;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background: radial-gradient(circle at 20% 10%, #123779 0%, var(--bg-deep-navy) 42%, #010b26 100%);
  color: var(--text-main);
}

.viewport {
  min-height: 100dvh;
  height: 100dvh;
  display: grid;
  place-items: center;
  padding: clamp(0.4rem, 1.2vh, 0.9rem);
}

.device-frame {
  width: min(94vw, 420px);
  height: min(97dvh, 860px);
  border-radius: clamp(22px, 5vw, 34px);
  background: linear-gradient(160deg, #0f1628, #1f2a40);
  padding: clamp(0.5rem, 1.4vh, 0.8rem);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.4), 0 4px 14px rgba(255, 255, 255, 0.12) inset;
}

.screen {
  width: 100%;
  height: 100%;
  border-radius: clamp(18px, 4.5vw, 28px);
  border: 1px solid rgba(195, 220, 255, 0.22);
  background: radial-gradient(circle at 50% -10%, #0f2a78, var(--bg-deep-navy) 45%, #01081d 100%);
  display: grid;
  grid-template-rows: auto 1fr auto auto;
  gap: clamp(0.55rem, 1.35vh, 0.85rem);
  padding: clamp(0.9rem, 2.2vh, 1.4rem) clamp(0.7rem, 2.1vw, 1.2rem) clamp(0.7rem, 1.7vh, 1rem);
}

.logo-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-image {
  width: min(84%, 300px);
  height: auto;
  object-fit: contain;
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.3));
}

.ebook-banner {
  --thumb-w: 104px;
  display: grid;
  grid-template-columns: var(--thumb-w) minmax(0, 1fr);
  gap: 0.7rem;
  align-items: center;
  min-height: 112px;
  overflow: hidden;
  text-decoration: none;
  border: 1px solid rgba(126, 242, 202, 0.22);
  border-radius: 0.95rem;
  background: linear-gradient(160deg, rgba(15, 42, 120, 0.6), rgba(3, 21, 63, 0.86));
  padding: 0.5rem;
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.28);
  transition: transform 0.18s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.ebook-banner:hover,
.ebook-banner:focus-visible {
  transform: translateY(-1px);
  border-color: #7ff2ca;
  box-shadow: 0 0 14px rgba(76, 235, 197, 0.22);
  outline: none;
}

.ebook-banner__thumb {
  width: 100%;
  max-width: 100%;
  min-width: 0;
  height: auto;
  aspect-ratio: 104 / 124;
  object-fit: contain;
  display: block;
  border-radius: 0.7rem;
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.ebook-banner__content {
  min-width: 0;
  overflow-wrap: anywhere;
}

.ebook-banner__label {
  font-size: 0.64rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #b7f7e3;
  margin-bottom: 0.18rem;
}

.ebook-banner__title {
  font-size: 0.84rem;
  line-height: 1.2;
  color: #fff;
  margin-bottom: 0.32rem;
}

.ebook-banner__cta {
  display: inline-block;
  font-size: 0.67rem;
  font-weight: 700;
  color: #ffffff;
  background: #ff3f00;
  border: 1px solid #ff3f00;
  border-radius: 999px;
  padding: 0.3rem 0.56rem;
}

.links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-content: center;
  gap: clamp(0.42rem, 1vh, 0.62rem);
}

.link-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.38rem;
  padding: clamp(0.36rem, 0.9vh, 0.54rem) clamp(0.46rem, 1vw, 0.72rem);
  border-radius: clamp(0.78rem, 2.2vw, 1rem);
  border: 1px solid var(--teal-border);
  background: linear-gradient(145deg, rgba(9, 71, 89, 0.95), rgba(15, 89, 103, 0.9));
  color: #ffffff;
  text-decoration: none;
  font-size: clamp(0.63rem, 1.45vw, 0.76rem);
  font-weight: 600;
  text-align: center;
  line-height: 1.2;
  box-shadow: 0 0 0 rgba(0, 0, 0, 0), 0 5px 10px rgba(1, 14, 26, 0.42);
  transition: transform 0.18s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.link-btn svg {
  width: clamp(0.72rem, 1.8vw, 0.88rem);
  height: clamp(0.72rem, 1.8vw, 0.88rem);
  fill: #7ff2ca;
  flex-shrink: 0;
}

.link-btn--wide {
  grid-column: 1 / -1;
  font-size: clamp(0.74rem, 1.8vw, 0.9rem);
  padding-block: clamp(0.5rem, 1.15vh, 0.7rem);
}

.link-btn--top {
  margin-bottom: clamp(0.35rem, 0.9vh, 0.6rem);
}

.link-btn--bottom {
  margin-top: clamp(0.35rem, 0.9vh, 0.6rem);
}

.link-btn:hover,
.link-btn:focus-visible {
  transform: translateY(-1px);
  border-color: #7ff2ca;
  box-shadow: 0 0 14px var(--teal-glow), 0 0 22px rgba(58, 241, 187, 0.25);
  outline: none;
}

.bottom-text {
  font-size: clamp(0.88rem, 2.25vw, 1rem);
  text-align: center;
  color: var(--text-muted);
  letter-spacing: 0.01em;
}

.footer-icons {
  display: flex;
  justify-content: center;
  gap: 0.9rem;
}

.footer-icons a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: clamp(1.5rem, 4.7vw, 1.95rem);
  height: clamp(1.5rem, 4.7vw, 1.95rem);
  color: #e7f1ff;
  border-radius: 0.35rem;
  border: 1px solid rgba(179, 215, 255, 0.22);
  background: rgba(8, 24, 62, 0.7);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.footer-icons a:hover,
.footer-icons a:focus-visible {
  border-color: #8fd7ff;
  box-shadow: 0 0 10px rgba(113, 230, 255, 0.3);
  outline: none;
}

.footer-icons svg {
  width: 74%;
  height: 74%;
  fill: currentColor;
}

@media (max-height: 690px) {
  .screen {
    padding-top: 0.72rem;
    gap: 0.45rem;
  }

  .logo-image {
    width: min(76%, 245px);
  }

  .ebook-banner {
    --thumb-w: 88px;
    padding: 0.42rem;
    gap: 0.52rem;
  }

  .ebook-banner__thumb {
    aspect-ratio: 88 / 106;
  }

  .ebook-banner__title {
    font-size: 0.76rem;
  }

  .ebook-banner__cta {
    font-size: 0.62rem;
  }

  .link-btn {
    font-size: clamp(0.58rem, 1.65vw, 0.7rem);
    padding-block: clamp(0.3rem, 0.78vh, 0.44rem);
  }

  .link-btn--wide {
    font-size: clamp(0.67rem, 1.9vw, 0.8rem);
    padding-block: clamp(0.4rem, 0.95vh, 0.56rem);
  }

  .bottom-text {
    font-size: clamp(0.76rem, 2vw, 0.9rem);
  }
}

@media (max-width: 390px) {
  .ebook-banner {
    --thumb-w: 76px;
    gap: 0.45rem;
  }

  .ebook-banner__label {
    font-size: 0.58rem;
  }

  .ebook-banner__title {
    font-size: 0.75rem;
  }

  .ebook-banner__cta {
    font-size: 0.6rem;
    padding: 0.26rem 0.5rem;
  }
}