/* ============================================
   CURIOSITY CREST — Brand System
   Ink & Ember palette · Bold Modern + Minimal
============================================ */

:root {
  /* Palette */
  --ink: #0f1d33;            /* deep navy */
  --ink-2: #1a2a47;
  --ink-soft: #2a3a57;
  --cream: #f6efe2;          /* warm cream */
  --cream-2: #efe6d4;
  --paper: #fbf7ee;
  --ember: #e36a3a;          /* ember orange accent */
  --ember-soft: #f08a5c;
  --ember-ink: #b14a20;
  --brass: #c9a04a;
  --slate: #5a6a82;
  --slate-soft: #8a97a8;
  --line: rgba(15, 29, 51, 0.12);
  --line-strong: rgba(15, 29, 51, 0.22);

  /* Type */
  --font-display: 'Fraunces', Georgia, serif;
  --font-sans: 'Inter', -apple-system, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', Menlo, monospace;

  /* Spacing scale */
  --s-1: 4px; --s-2: 8px; --s-3: 12px; --s-4: 16px;
  --s-5: 24px; --s-6: 32px; --s-7: 48px; --s-8: 64px;
  --s-9: 96px; --s-10: 128px;

  /* Radius */
  --r-s: 6px; --r-m: 12px; --r-l: 20px; --r-xl: 32px;

  /* Shadow */
  --shadow-sm: 0 1px 2px rgba(15, 29, 51, 0.06);
  --shadow-md: 0 8px 24px -8px rgba(15, 29, 51, 0.15);
  --shadow-book: 0 18px 40px -12px rgba(15, 29, 51, 0.35), 0 4px 8px -4px rgba(15, 29, 51, 0.2);

  /* Layout */
  --max-w: 1240px;
  --content-w: 720px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a { color: var(--ink); text-decoration: none; }
a:hover { color: var(--ember); }

/* ============== Type ============== */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-wrap: balance;
}
h1 { font-size: clamp(44px, 6vw, 88px); }
h2 { font-size: clamp(32px, 4vw, 52px); }
h3 { font-size: clamp(22px, 2.2vw, 28px); }
h4 { font-size: 18px; font-weight: 600; letter-spacing: -0.01em; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ember);
  font-weight: 500;
}

.lede {
  font-size: 20px;
  line-height: 1.55;
  color: var(--ink-soft);
  text-wrap: pretty;
  max-width: 640px;
}

/* ============== Layout ============== */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--s-5);
}

section { padding: var(--s-9) 0; }
@media (max-width: 720px) { section { padding: var(--s-7) 0; } }

/* ============== Buttons ============== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  padding: 14px 22px;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: -0.005em;
  border-radius: 999px;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: var(--ember);
  color: var(--paper);
}
.btn-primary:hover { background: var(--ember-ink); color: var(--paper); }
.btn-ink {
  background: var(--ink);
  color: var(--cream);
}
.btn-ink:hover { background: var(--ink-2); color: var(--cream); }
.btn-ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--ink);
}
.btn-ghost:hover { border-color: var(--ink); color: var(--ink); }
.btn-sm { padding: 9px 16px; font-size: 13px; }

/* ============== Nav ============== */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(251, 247, 238, 0.85);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px var(--s-5);
  max-width: var(--max-w);
  margin: 0 auto;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.nav-logo svg { width: 30px; height: 30px; }
.nav-links {
  display: flex;
  gap: var(--s-6);
  align-items: center;
}
.nav-links a {
  font-size: 14.5px;
  font-weight: 500;
  color: var(--ink-soft);
  letter-spacing: -0.005em;
}
.nav-links a:hover { color: var(--ember); }
.nav-cta { display: flex; gap: var(--s-3); align-items: center; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
  color: var(--ink);
}

@media (max-width: 860px) {
  .nav-links, .nav-cta .btn-ghost { display: none; }
  .nav-toggle { display: block; }
  .nav-mobile-open .nav-links {
    display: flex;
    position: absolute;
    top: 100%; left: 0; right: 0;
    flex-direction: column;
    background: var(--paper);
    padding: var(--s-5);
    gap: var(--s-4);
    border-bottom: 1px solid var(--line);
  }
}

/* ============== Book card ============== */
.book-card {
  display: flex;
  flex-direction: column;
  gap: var(--s-4);
  padding: 0;
  background: transparent;
  border-radius: var(--r-m);
  transition: transform 0.2s ease;
  cursor: pointer;
}
.book-card:hover { transform: translateY(-4px); }
.book-card:hover .book-cover { box-shadow: var(--shadow-book), 0 0 0 3px var(--ember); }
.book-cover {
  aspect-ratio: 2 / 3;
  background: var(--ink);
  border-radius: var(--r-s);
  overflow: hidden;
  box-shadow: var(--shadow-book);
  transition: box-shadow 0.2s ease;
  position: relative;
}
.book-cover img, .book-cover svg { width: 100%; height: 100%; object-fit: cover; }
.book-meta {
  display: flex;
  flex-direction: column;
  gap: var(--s-1);
}
.book-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ember);
  font-weight: 500;
}
.book-title-sm {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.015em;
  color: var(--ink);
}
.book-age {
  font-size: 13px;
  color: var(--slate);
}

/* ============== Grid ============== */
.grid-books {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--s-6) var(--s-5);
}
@media (max-width: 520px) {
  .grid-books { grid-template-columns: repeat(2, 1fr); gap: var(--s-5) var(--s-4); }
}

/* ============== Section header ============== */
.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--s-5);
  margin-bottom: var(--s-7);
  flex-wrap: wrap;
}
.section-head .head-text { max-width: 640px; }
.section-head h2 { margin-top: var(--s-3); }
.section-head .lede { margin-top: var(--s-3); }

/* ============== Footer ============== */
.footer {
  background: var(--ink);
  color: var(--cream);
  padding: var(--s-9) 0 var(--s-6);
  margin-top: var(--s-8);
}
.footer a { color: var(--cream); opacity: 0.75; }
.footer a:hover { color: var(--ember-soft); opacity: 1; }
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--s-7);
  margin-bottom: var(--s-7);
}
@media (max-width: 720px) {
  .footer-grid { grid-template-columns: 1fr 1fr; gap: var(--s-6); }
}
.footer-logo {
  font-family: var(--font-display);
  font-size: 28px;
  letter-spacing: -0.02em;
  color: var(--cream);
  margin-bottom: var(--s-3);
  display: flex; align-items: center; gap: var(--s-2);
}
.footer-logo svg { width: 32px; height: 32px; }
.footer p.tagline {
  color: var(--cream);
  opacity: 0.7;
  max-width: 320px;
  font-size: 14.5px;
  line-height: 1.55;
}
.footer h5 {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cream);
  opacity: 0.6;
  margin-bottom: var(--s-4);
}
.footer ul { list-style: none; display: flex; flex-direction: column; gap: var(--s-3); }
.footer ul a { font-size: 14.5px; }
.footer-bottom {
  border-top: 1px solid rgba(246, 239, 226, 0.12);
  padding-top: var(--s-5);
  display: flex;
  justify-content: space-between;
  gap: var(--s-5);
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--cream);
  opacity: 0.55;
}

/* ============== Email popup ============== */
.popup-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 29, 51, 0.6);
  backdrop-filter: blur(8px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--s-5);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.popup-backdrop.open { opacity: 1; pointer-events: auto; }
.popup {
  max-width: 900px;
  width: 100%;
  background: var(--paper);
  border-radius: var(--r-l);
  overflow: hidden;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  box-shadow: 0 40px 80px -20px rgba(0,0,0,0.4);
  transform: translateY(20px);
  transition: transform 0.3s ease;
  position: relative;
}
.popup-backdrop.open .popup { transform: translateY(0); }
@media (max-width: 720px) {
  .popup { grid-template-columns: 1fr; }
  .popup-visual { display: none; }
}
.popup-visual {
  background: var(--ink);
  color: var(--cream);
  padding: var(--s-7);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
}
.popup-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 20%, rgba(227, 106, 58, 0.18), transparent 40%),
    radial-gradient(circle at 80% 80%, rgba(201, 160, 74, 0.14), transparent 40%);
  pointer-events: none;
}
.popup-body {
  padding: var(--s-7);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: var(--s-4);
}
.popup-close {
  position: absolute;
  top: 14px; right: 14px;
  background: rgba(15, 29, 51, 0.08);
  border: none;
  width: 36px; height: 36px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 18px;
  color: var(--ink);
  display: flex; align-items: center; justify-content: center;
  z-index: 2;
  transition: background 0.15s ease;
}
.popup-close:hover { background: rgba(15, 29, 51, 0.18); }
.popup h3 {
  font-size: clamp(26px, 3vw, 36px);
  line-height: 1.05;
}
.popup .pack-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: rgba(227, 106, 58, 0.14);
  color: var(--ember);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  border-radius: 999px;
  width: fit-content;
  margin-bottom: 4px;
}
.popup-form {
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
  margin-top: var(--s-2);
}
.popup-form input {
  padding: 14px 16px;
  border: 1.5px solid var(--line-strong);
  border-radius: 10px;
  font-family: var(--font-sans);
  font-size: 15px;
  background: var(--paper);
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s ease;
}
.popup-form input:focus { border-color: var(--ember); }
.popup .fineprint {
  font-size: 12.5px;
  color: var(--slate);
  margin-top: 4px;
}

/* ============== Misc ============== */
.divider {
  height: 1px;
  background: var(--line);
  border: 0;
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--cream-2);
  border: 1px solid var(--line);
  color: var(--ink-soft);
  font-size: 13px;
  border-radius: 999px;
  font-weight: 500;
}
.chip.ink { background: var(--ink); color: var(--cream); border-color: var(--ink); }
.chip.ember { background: rgba(227, 106, 58, 0.12); color: var(--ember-ink); border-color: rgba(227, 106, 58, 0.3); }