/* Milestone Languages — design system */

:root {
  --bg: #f7f7fb;
  --surface: #ffffff;
  --surface-alt: #f1f2f8;
  --text: #16161f;
  --text-muted: #5c5e6d;
  --border: #e4e4ee;
  --primary: #4338ca;
  --primary-dark: #372aa8;
  --primary-contrast: #ffffff;
  --accent: #f59e0b;
  --shadow: 0 1px 2px rgba(16,16,40,0.04), 0 8px 24px rgba(16,16,40,0.06);
  --shadow-hover: 0 4px 8px rgba(16,16,40,0.06), 0 16px 32px rgba(16,16,40,0.10);
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --font-heading: "Poppins", "Inter", system-ui, sans-serif;
  --font-body: "Inter", system-ui, sans-serif;
}

:root[data-theme="dark"] {
  --bg: #0f0f16;
  --surface: #17171f;
  --surface-alt: #1e1e29;
  --text: #f2f2f7;
  --text-muted: #a3a4b5;
  --border: #2b2b39;
  --primary: #818cf8;
  --primary-dark: #6366f1;
  --primary-contrast: #101018;
  --shadow: 0 1px 2px rgba(0,0,0,0.3), 0 8px 24px rgba(0,0,0,0.35);
  --shadow-hover: 0 4px 10px rgba(0,0,0,0.35), 0 20px 40px rgba(0,0,0,0.45);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f0f16;
    --surface: #17171f;
    --surface-alt: #1e1e29;
    --text: #f2f2f7;
    --text-muted: #a3a4b5;
    --border: #2b2b39;
    --primary: #818cf8;
    --primary-dark: #6366f1;
    --primary-contrast: #101018;
    --shadow: 0 1px 2px rgba(0,0,0,0.3), 0 8px 24px rgba(0,0,0,0.35);
    --shadow-hover: 0 4px 10px rgba(0,0,0,0.35), 0 20px 40px rgba(0,0,0,0.45);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 0.5em;
}
p { margin: 0 0 1em; color: var(--text-muted); }
a { color: var(--primary); text-decoration: none; }
img { max-width: 100%; display: block; }
.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}
section { padding: 56px 0; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: 999px;
  padding: 12px 24px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); box-shadow: var(--shadow-hover); }
.btn-outline { background: transparent; color: var(--text); border-color: var(--border); }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.btn-amazon { background: #ff9900; color: #111; width: 100%; font-size: 1.05rem; padding: 14px 24px; }
.btn-amazon:hover { background: #e88a00; box-shadow: var(--shadow-hover); }
.btn-lg { padding: 16px 32px; font-size: 1.05rem; }
.btn-sm { padding: 8px 16px; font-size: 0.85rem; }
.btn-block { width: 100%; margin-top: 14px; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); }
.site-logo { height: 40px; width: auto; display: block; }
.footer-logo-wrap .site-logo { height: 34px; }

:root[data-theme="dark"] .site-logo { filter: invert(1); }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .site-logo { filter: invert(1); }
}
.site-nav { display: flex; align-items: center; gap: 28px; }
.site-nav > a { color: var(--text); font-weight: 500; }
.site-nav > a:hover { color: var(--primary); }
.nav-cta {
  background: var(--primary);
  color: #fff !important;
  padding: 10px 20px;
  border-radius: 999px;
  font-weight: 600;
}
.nav-cta:hover { background: var(--primary-dark); }
.nav-dropdown { position: relative; }
.nav-dropdown-btn {
  background: none; border: none; cursor: pointer;
  font: inherit; color: var(--text); font-weight: 500;
  display: flex; align-items: center; gap: 4px; padding: 0;
}
.nav-dropdown-btn:hover { color: var(--primary); }
.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 16px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-hover);
  padding: 8px;
  display: none;
  flex-direction: column;
  min-width: 260px;
}
.nav-dropdown.open .nav-dropdown-menu { display: flex; }
.nav-dropdown-menu a {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  color: var(--text);
  font-weight: 500;
  font-size: 0.92rem;
}
.nav-dropdown-menu a:hover { background: var(--surface-alt); color: var(--primary); }
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; }

@media (max-width: 860px) {
  .nav-toggle { display: flex; }
  .site-nav {
    position: absolute;
    top: 72px; left: 0; right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 24px 20px;
    display: none;
  }
  .site-nav.open { display: flex; }
  .site-nav > a, .nav-dropdown-btn { padding: 12px 0; width: 100%; justify-content: flex-start; }
  .nav-dropdown-menu {
    position: static; transform: none; box-shadow: none;
    border: none; padding: 0 0 0 12px; min-width: 0;
  }
  .nav-cta { margin-top: 8px; text-align: center; }
}

/* ---------- Hero ---------- */
.hero {
  padding: 96px 0 72px;
  background:
    radial-gradient(circle at 15% 20%, color-mix(in srgb, var(--primary) 18%, transparent), transparent 55%),
    radial-gradient(circle at 85% 0%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 50%),
    var(--surface-alt);
  text-align: center;
}
.hero-inner { max-width: 780px; }
.eyebrow {
  display: inline-block;
  font-weight: 600;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--primary);
  background: color-mix(in srgb, var(--primary) 12%, transparent);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 20px;
}
.hero h1 { font-size: clamp(2.2rem, 5vw, 3.4rem); margin-bottom: 20px; }
.hero-sub { font-size: 1.1rem; max-width: 620px; margin: 0 auto 32px; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ---------- Section headings ---------- */
.section-heading-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}
.section-heading-row h2 { margin: 0; font-size: 1.7rem; }
.count-pill {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  background: var(--surface-alt);
  padding: 6px 14px;
  border-radius: 999px;
}
.section-lede { margin-top: -12px; }

/* ---------- Category grid ---------- */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}
.category-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
  position: relative;
  overflow: hidden;
}
.category-card::before {
  content: "";
  position: absolute; inset: 0 0 auto 0; height: 5px;
  background: linear-gradient(90deg, var(--cat-color), var(--cat-color-dark));
}
.category-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--cat-color);
}
.category-icon { font-size: 2rem; display: inline-block; margin-bottom: 14px; }
.category-card h3 { color: var(--text); font-size: 1.15rem; margin-bottom: 8px; }
.category-card p { font-size: 0.92rem; margin-bottom: 16px; }
.category-count {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--cat-color-dark);
}

/* ---------- Book cover placeholder ---------- */
.book-cover {
  aspect-ratio: 2 / 3;
  border-radius: var(--radius-sm);
  background: linear-gradient(155deg, var(--cover-color), var(--cover-color-dark));
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 18px;
  position: relative;
  overflow: hidden;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.12);
}
.book-cover::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 20%, rgba(255,255,255,0.25), transparent 55%);
}
.cover-icon { font-size: 2rem; margin-bottom: 8px; }
.cover-flag { position: absolute; top: 12px; right: 14px; font-size: 1.3rem; }
.cover-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.95rem;
  line-height: 1.3;
  position: relative;
  z-index: 1;
}
.cover-brand {
  position: absolute;
  bottom: 12px;
  font-size: 0.65rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  opacity: 0.85;
}
.book-cover-sm .cover-title { font-size: 0.78rem; }
.book-cover-sm .cover-icon { font-size: 1.4rem; }

.book-cover-real { padding: 0; background: none; box-shadow: inset 0 0 0 1px var(--border); }
.book-cover-real::after { content: none; }
.book-cover-real img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: inherit;
}

/* ---------- Book grid / card ---------- */
.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 22px;
}
.book-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
  color: var(--text);
}
.book-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.book-card-body { padding-top: 14px; display: flex; flex-direction: column; flex: 1; }
.book-card h3 {
  font-size: 0.98rem;
  margin-bottom: 6px;
  min-height: 2.5em;
  color: var(--text);
}
.book-card-lang { font-size: 0.82rem; margin-bottom: 12px; }
.book-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  font-size: 0.85rem;
}
.book-card-footer .price { font-weight: 700; font-size: 1.05rem; color: var(--text); }
.rating { color: var(--accent); font-size: 0.8rem; white-space: nowrap; }
.rating small { color: var(--text-muted); }

/* ---------- About / stats ---------- */
.about-section { background: var(--surface-alt); border-radius: var(--radius-lg); }
.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 40px;
  align-items: center;
}
.stats-row { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.stat strong { display: block; font-family: var(--font-heading); font-size: 1.8rem; color: var(--primary); }
.stat span { font-size: 0.85rem; color: var(--text-muted); }
@media (max-width: 760px) { .about-grid { grid-template-columns: 1fr; } }

/* ---------- CTA strip ---------- */
.cta-strip {
  text-align: center;
  background: linear-gradient(135deg, var(--primary), #8b5cf6);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 56px 32px;
}
.cta-strip h2 { color: #fff; }
.cta-strip p { color: rgba(255,255,255,0.85); max-width: 520px; margin-left: auto; margin-right: auto; }
.cta-strip .btn-primary { background: #fff; color: var(--primary); margin-top: 8px; }
.cta-strip .btn-primary:hover { background: #f3f3f3; }

/* ---------- Category hero ---------- */
.category-hero {
  padding: 72px 0;
  text-align: center;
  color: #fff;
  background: linear-gradient(135deg, var(--hero-color), var(--hero-color-dark));
}
.category-hero .hero-icon { font-size: 2.6rem; display: block; margin-bottom: 12px; }
.category-hero h1 { color: #fff; font-size: clamp(1.8rem, 4vw, 2.6rem); }
.category-hero p { color: rgba(255,255,255,0.9); max-width: 560px; margin-left: auto; margin-right: auto; }
.category-hero .hero-desc { font-size: 0.95rem; color: rgba(255,255,255,0.8); }

/* ---------- Breadcrumbs ---------- */
.breadcrumbs { padding-top: 24px; font-size: 0.85rem; color: var(--text-muted); }
.breadcrumbs a { color: var(--text-muted); }
.breadcrumbs a:hover { color: var(--primary); }
.breadcrumbs span { color: var(--text); }

/* ---------- Book detail ---------- */
.book-detail {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 48px;
  padding-top: 32px;
}
.book-detail-cover .book-cover { max-width: 300px; }
.badge {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 6px 12px;
  border-radius: 999px;
  margin-bottom: 14px;
}
.book-detail-info h1 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-bottom: 6px; }
.book-translation { font-style: italic; color: var(--text-muted); margin: 0 0 10px; font-size: 0.95rem; }
.book-subtitle { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 16px; }
.book-tagline { font-style: italic; font-size: 1.08rem; color: var(--text); margin-bottom: 18px; }
.book-description { font-size: 1.02rem; }
.book-features { margin: 0 0 20px; padding-left: 20px; color: var(--text-muted); font-size: 0.92rem; }
.book-features li { margin-bottom: 4px; }
.exam-banner {
  background: #b91c1c;
  color: #fff;
  font-weight: 700;
  text-align: center;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
  font-size: 0.9rem;
}
.cta-banner {
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, transparent);
  border-radius: var(--radius);
  padding: 14px 18px;
  font-size: 0.92rem;
  margin-bottom: 24px;
  color: var(--text);
}
@media (max-width: 760px) {
  .book-detail { grid-template-columns: 1fr; }
  .book-detail-cover .book-cover { max-width: 220px; margin: 0 auto; }
}

/* ---------- Buy box ---------- */
.buy-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  max-width: 420px;
  box-shadow: var(--shadow);
}
.buy-price { font-family: var(--font-heading); font-size: 2rem; font-weight: 800; color: var(--text); }
.buy-price span { font-size: 1rem; font-weight: 500; color: var(--text-muted); }
.buy-rating { margin: 8px 0 18px; color: var(--accent); font-size: 0.9rem; }
.buy-rating span { color: var(--text-muted); margin-left: 4px; }
.buy-note { font-size: 0.85rem; margin-top: 14px; }
.buy-meta { list-style: none; padding: 0; margin: 16px 0 0; font-size: 0.85rem; border-top: 1px solid var(--border); padding-top: 14px; }
.buy-meta li { display: flex; justify-content: space-between; padding: 4px 0; color: var(--text-muted); }
.buy-meta strong { color: var(--text); font-weight: 600; }

/* ---------- Extra materials ---------- */
.extra-materials { background: var(--surface-alt); }
.download-list {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}
.download-item {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 18px;
}
.dl-icon { font-size: 1.4rem; }
.dl-info { display: flex; flex-direction: column; flex: 1; }
.dl-title { font-weight: 600; font-size: 0.95rem; }
.dl-meta { font-size: 0.8rem; color: var(--text-muted); }

/* ---------- Related ---------- */
.related-section h2 { font-size: 1.4rem; }
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 18px;
}
.related-card { color: var(--text); display: flex; flex-direction: column; gap: 8px; }
.related-card .book-cover { margin-bottom: 4px; }
.related-title { font-size: 0.85rem; font-weight: 600; line-height: 1.3; }
.related-price { font-size: 0.85rem; font-weight: 700; color: var(--primary); }

/* ---------- Book pager ---------- */
.book-pager {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-bottom: 64px;
  font-size: 0.9rem;
  font-weight: 600;
}

/* ---------- Legal pages ---------- */
.legal-page { max-width: 760px; }
.legal-page h1 { font-size: 2rem; }
.legal-page h2 { font-size: 1.2rem; margin-top: 32px; }
.legal-page ul { color: var(--text-muted); }
.fine-print { font-size: 0.78rem; color: var(--text-muted); opacity: 0.85; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--surface-alt);
  border-top: 1px solid var(--border);
  padding: 56px 0 24px;
  margin-top: 64px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 32px;
}
.footer-brand p { font-size: 0.9rem; max-width: 320px; }
.footer-col h4 { font-size: 0.9rem; margin-bottom: 12px; }
.footer-col ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.footer-col a { color: var(--text-muted); font-size: 0.9rem; }
.footer-col a:hover { color: var(--primary); }
.newsletter { margin-top: 20px; }
.newsletter label { font-size: 0.82rem; font-weight: 600; display: block; margin-bottom: 8px; }
.newsletter-row { display: flex; gap: 8px; }
.newsletter-row input {
  flex: 1;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-size: 0.85rem;
}
.newsletter-row button {
  padding: 10px 18px;
  border-radius: 999px;
  border: none;
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  font-size: 0.85rem;
}
.newsletter-row button:hover { background: var(--primary-dark); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--text-muted);
}
.footer-bottom p { margin: 0; }
@media (max-width: 860px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 520px) {
  .footer-grid { grid-template-columns: 1fr; }
}