/* =========================
   COLOR THEME & GLOBAL
   ========================= */

:root {
  --bg: #050b18;                 /* Deep space navy */
  --bg-alt: #0c1a33;             /* Rich blue-gray */
  --accent: #3ba4ff;             /* Bright ocean blue */
  --accent-soft: rgba(59, 164, 255, 0.18);
  --accent-strong: #6bc5ff;
  --text-main: #e6f1ff;          /* Soft icy white */
  --text-muted: #9db4d1;         /* Cool blue-gray */
  --border-subtle: rgba(90, 140, 185, 0.4);
  --radius-lg: 1.5rem;
  --shadow-soft: 0 18px 40px rgba(3, 14, 30, 0.85);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text-main);
  line-height: 1.6;
  background: radial-gradient(circle at top, #183a62 0, #050b18 50%, #020510 100%);
  background-size: 160% 160%;
  animation: bgShift 36s ease-in-out infinite;
}

/* Animated background gradient */
@keyframes bgShift {
  0%   { background-position: 0% 0%; }
  50%  { background-position: 100% 100%; }
  100% { background-position: 0% 0%; }
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

/* =========================
   HEADER & NAV
   ========================= */

header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: linear-gradient(
    to bottom,
    rgba(5, 11, 24, 0.95),
    rgba(5, 11, 24, 0.75),
    transparent
  );
  border-bottom: 1px solid var(--border-subtle);
}

.nav-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-brand h1 {
  margin: 0;
  font-size: 1.1rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.nav-tagline {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.18em;
}

.nav-author-photo {
  width: 58px;
  height: 58px;
  object-fit: cover;
  border-radius: 50%;
  border: 2px solid rgba(107, 197, 255, 0.9);
  box-shadow:
    0 0 0 3px rgba(59, 164, 255, 0.25),
    0 10px 22px rgba(0, 0, 0, 0.7);
}

/* nav links */

nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
}

nav a {
  position: relative;
  color: var(--text-muted);
  padding-bottom: 0.25rem;
}

nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  height: 2px;
  width: 0;
  border-radius: 999px;
  background: linear-gradient(to right, var(--accent), var(--accent-strong));
  transition: width 0.18s ease-out;
}

nav a:hover,
nav a:focus-visible {
  color: var(--text-main);
}

nav a:hover::after,
nav a:focus-visible::after {
  width: 100%;
}

/* =========================
   LAYOUT SECTIONS
   ========================= */

.section {
  max-width: 1120px;
  margin: 0 auto;
  padding: 4rem 1.25rem;
}

.section-heading {
  margin-bottom: 1.75rem;
}

.section-heading h2 {
  margin: 0 0 0.5rem 0;
  font-size: 1.4rem;
}

.section-heading p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* =========================
   BUTTONS
   ========================= */

.btn {
  padding: 0.75rem 1.4rem;
  border-radius: 999px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  font-size: 0.9rem;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s ease-out, box-shadow 0.15s ease-out;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #050b18;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.6);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.75);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(120, 160, 200, 0.5);
  color: var(--text-main);
}

.btn-ghost:hover {
  border-color: var(--accent-strong);
  box-shadow: 0 10px 24px rgba(2, 28, 58, 0.9);
}

/* =========================
   HERO
   ========================= */

.hero {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 3rem;
  align-items: center;
  padding-top: 3.25rem;
}

.eyebrow {
  font-size: 0.75rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.22em;
}

.hero-title {
  font-size: clamp(2.3rem, 3vw, 2.9rem);
  margin: 0.5rem 0 0.75rem;
}

.hero-subtitle {
  color: var(--text-muted);
  max-width: 38rem;
}

.hero-highlight {
  display: inline-flex;
  gap: 0.5rem;
  background: var(--accent-soft);
  border: 1px solid rgba(59, 164, 255, 0.55);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  color: var(--accent);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.78rem;
}

.hero-cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin: 1.4rem 0 0.8rem;
}

.hero-note {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* translucent hero card */

.hero-cover {
  border-radius: calc(var(--radius-lg) + 0.4rem);
  border: 1px solid rgba(107, 197, 255, 0.5);
  background:
    radial-gradient(circle at top left, rgba(59, 164, 255, 0.25), transparent 55%),
    radial-gradient(circle at bottom right, rgba(56, 189, 248, 0.18), transparent 55%),
    rgba(5, 11, 24, 0.92);
  box-shadow: var(--shadow-soft);
  padding: 1.4rem;
}

.hero-badge {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--text-muted);
  border-radius: 999px;
  border: 1px solid rgba(148, 188, 235, 0.7);
  padding: 0.3rem 0.8rem;
  background: rgba(4, 18, 38, 0.9);
  display: inline-block;
  margin-bottom: 1rem;
}

/* book spine visual */

.hero-book-spine {
  border-radius: 1.1rem;
  border: 1px solid rgba(120, 180, 235, 0.9);
  padding: 1.1rem 1.2rem;
  text-transform: uppercase;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  aspect-ratio: 3 / 4;
  background:
    linear-gradient(135deg, rgba(59, 164, 255, 0.32), rgba(58, 130, 255, 0.08)),
    radial-gradient(circle at 20% 0, #06152b 0, #0c1a33 40%, #050b18 100%);
}

.hero-book-label {
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--accent-strong);
}

.hero-book-title {
  font-size: 1.2rem;
  letter-spacing: 0.18em;
  line-height: 1.4;
}

.hero-book-author {
  font-size: 0.9rem;
  letter-spacing: 0.18em;
  color: var(--text-muted);
}

.hero-stats {
  margin-top: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.hero-stats span {
  border-radius: 999px;
  border: 1px solid rgba(120, 160, 210, 0.55);
  padding: 0.2rem 0.6rem;
  background: rgba(5, 14, 30, 0.9);
}

/* =========================
   BOOKS
   ========================= */

.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.75rem;
}

.book-card {
  background: rgba(12, 26, 51, 0.94);
  padding: 1.4rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  box-shadow: 0 14px 32px rgba(2, 12, 25, 0.85);
  transition: border-color 0.18s ease-out, box-shadow 0.18s ease-out, transform 0.18s ease-out;
}

/* subtle neon hover */
.book-card:hover {
  border-color: rgba(107, 197, 255, 0.95);
  box-shadow:
    0 0 0 1px rgba(59, 164, 255, 0.55),
    0 18px 40px rgba(4, 26, 60, 0.95);
  transform: translateY(-2px);
}

.book-top {
  display: grid;
  grid-template-columns: 0.55fr 1.45fr;
  gap: 0.85rem;
}

/* blue-tinted placeholder covers */

.book-cover {
  border-radius: 1rem;
  padding: 0.75rem;
  font-size: 0.8rem;
  text-transform: uppercase;
  text-align: center;
  color: var(--text-muted);
  border: 1px solid rgba(118, 185, 240, 0.7);
  background:
    linear-gradient(135deg, rgba(59, 164, 255, 0.35), rgba(42, 115, 230, 0.18)),
    radial-gradient(circle at 0 0, rgba(111, 198, 255, 0.4), transparent 55%),
    #071124;
  box-shadow: 0 10px 24px rgba(3, 17, 38, 0.9);
}

.book-tag {
  color: var(--accent-strong);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  margin-bottom: 0.25rem;
}

.book-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.book-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.book-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.link-pill {
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  border: 1px solid rgba(120, 160, 200, 0.6);
  font-size: 0.8rem;
  color: var(--text-muted);
  transition: border-color 0.18s ease-out, color 0.18s ease-out, box-shadow 0.18s ease-out;
}

.link-pill:hover {
  border-color: var(--accent-strong);
  color: var(--accent-strong);
  box-shadow: 0 0 0 1px rgba(107, 197, 255, 0.6);
}

.format-label {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.format-label span {
  color: var(--accent-strong);
}

/* =========================
   ABOUT / BIO
   ========================= */

.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 2.5rem;
}

.about-card {
  background: rgba(12, 26, 51, 0.94);
  padding: 1.75rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-soft);
  font-size: 0.95rem;
}

.meta-label {
  color: var(--accent-strong);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  margin-bottom: 0.15rem;
}

.about-meta {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
  font-size: 0.86rem;
  color: var(--text-muted);
}

/* quote card with subtle glow */

.quote-card {
  background:
    radial-gradient(circle at top, rgba(59, 164, 255, 0.22), transparent 55%),
    rgba(10, 24, 48, 0.96);
  padding: 1.5rem;
  border: 1px solid rgba(127, 196, 255, 0.7);
  border-radius: var(--radius-lg);
  box-shadow:
    0 0 0 1px rgba(59, 164, 255, 0.4),
    0 18px 40px rgba(7, 26, 60, 0.95);
  font-size: 0.9rem;
  color: var(--text-muted);
}

.quote-author {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-main);
}

/* =========================
   CONTACT / NEWSLETTER
   ========================= */

.contact-grid {
  display: grid;
  grid-template-columns: 1.2fr 1.1fr;
  gap: 2rem;
}

.newsletter-card,
.contact-card {
  background: rgba(12, 26, 51, 0.94);
  padding: 1.6rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-soft);
  font-size: 0.9rem;
  color: var(--text-muted);
}

.newsletter-card h3,
.contact-card h3 {
  margin-top: 0;
  color: var(--text-main);
}

.newsletter-form {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.input {
  flex: 1 1 180px;
  padding: 0.65rem 0.8rem;
  border-radius: 999px;
  border: 1px solid rgba(120, 160, 200, 0.7);
  background: rgba(7, 17, 33, 0.96);
  color: var(--text-main);
  font-size: 0.9rem;
}

.input::placeholder {
  color: #6d86aa;
}

.contact-list {
  list-style: none;
  margin: 0.75rem 0 0;
  padding: 0;
}

.contact-list li {
  margin-bottom: 0.5rem;
}

.contact-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--accent-strong);
}

/* =========================
   FOOTER
   ========================= */

footer {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem 1.25rem 2.4rem;
  border-top: 1px solid rgba(90, 140, 185, 0.45);
  font-size: 0.8rem;
}

footer a {
  color: var(--accent-strong);
}

/* =========================
   RESPONSIVE
   ========================= */

@media (max-width: 860px) {
  .hero,
  .about-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 2.5rem;
  }

  .nav-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  nav ul {
    font-size: 0.85rem;
  }
}

@media (max-width: 600px) {
  .section {
    padding-inline: 1rem;
  }

  .book-top {
    grid-template-columns: 1fr;
  }

  .nav-author-photo {
    width: 52px;
    height: 52px;
  }
}