:root {
  --navy: #1b3a7a; --navy-deep: #1f2a3c; --blue: #3b82f6; --green: #0c8c62;
  --bg: #f6f8fb; --surface: #ffffff; --text: #182033; --muted: #4f5b71; --rule: #dfe5ee; --link: #1d4ed8;
  --hero-text: #ffffff; --hero-muted: rgba(255,255,255,.82);
  --shadow: 0 10px 30px rgba(24,32,51,.12);
  --c-dark: var(--navy); --c-accent: var(--blue);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1522; --surface: #171f31; --text: #e8edf5; --muted: #a7b2c6; --rule: #2a3449; --link: #8fb4ff;
    --shadow: 0 10px 30px rgba(0,0,0,.45);
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font: 17px/1.6 Inter, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
a { color: var(--link); }
img { display: block; max-width: 100%; height: auto; }
.wrap { width: min(1120px, 100% - 32px); margin-inline: auto; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--surface); color: var(--text); padding: 8px 12px; border-radius: 6px; }
.skip:focus { left: 16px; z-index: 10; }

/* series navigation */
nav.top { background: var(--navy-deep); }
nav.top .wrap { display: flex; gap: 4px; padding: 6px 0; font-size: .88rem; font-weight: 500; }
nav.top a { color: rgba(255,255,255,.75); text-decoration: none; padding: 6px 12px; border-radius: 6px; }
nav.top a:hover, nav.top a:focus-visible { background: rgba(255,255,255,.12); color: #fff; }
nav.top a[aria-current] { color: #fff; background: rgba(255,255,255,.14); }

/* hero */
.hero {
  background:
    radial-gradient(60% 80% at 80% 10%, rgba(59,130,246,.35), transparent 60%),
    radial-gradient(50% 70% at 10% 90%, rgba(12,140,98,.35), transparent 60%),
    linear-gradient(135deg, var(--navy), var(--navy-deep));
  color: var(--hero-text); padding: 64px 0 56px;
  border-bottom: 6px solid; border-image: linear-gradient(90deg, var(--blue), var(--green)) 1;
}
.whitepapers .hero {
  background:
    radial-gradient(60% 80% at 85% 10%, rgba(12,140,98,.40), transparent 60%),
    radial-gradient(50% 70% at 10% 90%, rgba(59,130,246,.30), transparent 60%),
    linear-gradient(135deg, var(--navy-deep), var(--navy));
}
.eyebrow { margin: 0 0 12px; font-size: .85rem; font-weight: 600; letter-spacing: .14em; text-transform: uppercase; color: var(--hero-muted); }
.hero h1 { margin: 0; font-size: clamp(2rem, 1.2rem + 3.6vw, 3.5rem); font-weight: 800; letter-spacing: -.02em; line-height: 1.1; }
.lede { max-width: 46rem; margin: 18px 0 0; font-size: 1.15rem; color: var(--hero-muted); }
.herostats { display: flex; flex-wrap: wrap; gap: 14px 40px; margin-top: 30px; }
.herostats div { display: flex; flex-direction: column; }
.herostats strong { font-size: 2rem; font-weight: 800; line-height: 1.1; }
.herostats span { font-size: .85rem; color: var(--hero-muted); text-transform: uppercase; letter-spacing: .08em; }
.jump { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 30px; }
.jump a { color: var(--hero-text); text-decoration: none; padding: 6px 12px; border-radius: 999px; border: 1px solid rgba(255,255,255,.35); background: rgba(255,255,255,.08); font-weight: 500; font-size: .9rem; }
.jump a:hover, .jump a:focus-visible { background: rgba(255,255,255,.18); }

main { padding: 48px 0 24px; }

/* cards on the front page */
.cards { display: grid; gap: 28px; }
.card {
  position: relative; display: grid; grid-template-columns: 150px minmax(0, 1fr) minmax(0, 1.15fr); gap: 28px; align-items: start;
  background: var(--surface); border: 1px solid var(--rule); border-radius: 14px; padding: 24px 24px 24px 28px;
  box-shadow: var(--shadow); overflow: hidden; scroll-margin-top: 16px;
}
.card::before { content: ""; position: absolute; inset: 0 auto 0 0; width: 6px; background: linear-gradient(180deg, var(--c-accent), var(--c-dark)); }
.cover img { border-radius: 5px; box-shadow: 0 6px 18px rgba(0,0,0,.3); transition: transform 120ms ease; }
.cover:hover img { transform: translateY(-2px); }
.book-no { margin: 0 0 6px; font-size: .78rem; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--green); }
.wip { margin-left: 8px; padding: 1px 8px; border-radius: 999px; border: 1px solid var(--rule); color: var(--muted); letter-spacing: .04em; text-transform: none; font-weight: 500; }
.card h3 { margin: 0; font-size: 1.5rem; font-weight: 800; letter-spacing: -.015em; line-height: 1.15; }
.card h3 a { color: inherit; text-decoration: none; }
.card h3 a:hover, .card h3 a:focus-visible { text-decoration: underline; }
.subtitle { margin: 8px 0 12px; font-weight: 500; color: var(--muted); font-size: .98rem; }
.pitch { margin: 0 0 14px; font-size: .95rem; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 14px; padding: 0; }
.chips span { font-size: .8rem; font-weight: 600; padding: 3px 10px; border-radius: 999px; background: color-mix(in srgb, var(--c-accent) 18%, transparent); border: 1px solid color-mix(in srgb, var(--c-accent) 45%, transparent); }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 18px; margin: 0; }
.button { display: inline-block; text-decoration: none; color: #fff; background: linear-gradient(135deg, var(--blue), var(--green)); padding: 10px 16px; border-radius: 8px; font-weight: 600; font-size: .95rem; }
.button:hover, .button:focus-visible { filter: brightness(1.08); }
.ghost { display: inline-block; text-decoration: none; color: #fff; padding: 9px 15px; border-radius: 8px; border: 1px solid rgba(255,255,255,.45); background: rgba(255,255,255,.08); font-weight: 500; font-size: .95rem; }
.ghost:hover, .ghost:focus-visible { background: rgba(255,255,255,.18); }
.link { font-weight: 500; font-size: .95rem; }

/* preview strips */
.strip { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; align-self: center; }
.strip img { width: 100%; height: auto; border-radius: 6px; border: 1px solid var(--rule); box-shadow: 0 3px 10px rgba(24,32,51,.15); transition: transform 120ms ease; background: #fff; }
.strip:hover img { transform: translateY(-2px); }
.strip.one { grid-template-columns: 1fr; }

.companion { margin-top: 48px; padding-top: 36px; border-top: 1px solid var(--rule); }
.companion > h2 { margin: 0 0 20px; font-size: 1.5rem; font-weight: 800; letter-spacing: -.015em; }
.note { margin: 36px 0 0; color: var(--muted); max-width: 60rem; font-size: .95rem; }
footer { padding: 32px 0 48px; color: var(--muted); font-size: .9rem; }
footer p { margin: 0; }

/* book pages */
.detail .hero { background:
    radial-gradient(60% 90% at 85% 0%, color-mix(in srgb, var(--c-accent) 38%, transparent), transparent 62%),
    linear-gradient(135deg, var(--c-dark), color-mix(in srgb, var(--c-dark) 70%, #000)); border-image: linear-gradient(90deg, var(--c-accent), var(--c-dark)) 1; padding: 48px 0; }
.hero-grid { display: grid; grid-template-columns: 200px minmax(0, 1fr); gap: 36px; align-items: center; }
.hero-cover { border-radius: 6px; box-shadow: 0 10px 30px rgba(0,0,0,.5); }
.book-hero h1 { font-size: clamp(1.9rem, 1.2rem + 3vw, 3rem); }
.book-hero .chips { margin: 22px 0 18px; }
.book-hero .chips span { background: rgba(255,255,255,.12); border-color: rgba(255,255,255,.3); color: #fff; }
.book-hero .actions { margin-top: 4px; }
.crumbs { margin: 0 0 8px; font-size: .9rem; color: var(--muted); }
.section { margin: 8px 0 4px; font-size: 1.4rem; font-weight: 800; letter-spacing: -.01em; }

.slides { list-style: none; margin: 20px 0 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 16px; }
.slides a { position: relative; display: block; border-radius: 8px; overflow: hidden; border: 1px solid var(--rule); box-shadow: 0 3px 10px rgba(24,32,51,.12); background: #fff; transition: transform 120ms ease, box-shadow 120ms ease; }
.slides a:hover, .slides a:focus-visible { transform: translateY(-3px); box-shadow: 0 8px 20px rgba(24,32,51,.22); }
.slides img { width: 100%; height: auto; aspect-ratio: 16 / 9; object-fit: cover; }
.slides span { position: absolute; right: 6px; bottom: 6px; font-size: .72rem; font-weight: 600; padding: 1px 7px; border-radius: 999px; background: rgba(24,32,51,.78); color: #fff; }

.lightbox { position: fixed; inset: 0; z-index: 50; background: rgba(8,12,22,.92); display: flex; align-items: center; justify-content: center; flex-direction: column; padding: 24px; }
.lightbox[hidden] { display: none; }
.lightbox img { max-width: min(1200px, 100%); max-height: 80vh; width: auto; border-radius: 6px; box-shadow: 0 10px 40px rgba(0,0,0,.6); background: #fff; }
.lightbox button { position: absolute; background: rgba(255,255,255,.12); color: #fff; border: 0; border-radius: 999px; width: 48px; height: 48px; font-size: 1.8rem; line-height: 1; cursor: pointer; }
.lightbox button:hover, .lightbox button:focus-visible { background: rgba(255,255,255,.28); }
.lb-x { top: 16px; right: 16px; } .lb-p { left: 16px; top: 50%; } .lb-n { right: 16px; top: 50%; }
.lb-c { color: rgba(255,255,255,.85); margin: 14px 0 0; font-size: .95rem; text-align: center; max-width: 60rem; }

.shot img { width: 100%; max-width: 800px; margin-inline: auto; border-radius: 10px; border: 1px solid var(--rule); box-shadow: var(--shadow); }
.shot { margin: 0 0 32px; }
.part { margin: 0 0 28px; }
.part h3 { margin: 0 0 10px; font-size: .85rem; letter-spacing: .12em; text-transform: uppercase; color: var(--green); font-weight: 600; }
.chapters { list-style: none; margin: 0; padding: 0; background: var(--surface); border: 1px solid var(--rule); border-radius: 12px; overflow: hidden; }
.chapters li + li { border-top: 1px solid var(--rule); }
.chapters a { display: grid; grid-template-columns: 8.5rem minmax(0, 1fr) auto; gap: 16px; align-items: baseline; padding: 12px 18px; color: inherit; text-decoration: none; }
.chapters a:hover, .chapters a:focus-visible { background: color-mix(in srgb, var(--c-accent) 14%, transparent); }
.chapters .no { font-size: .8rem; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); }
.chapters .t { font-weight: 600; }
.chapters .m { font-size: .85rem; color: var(--muted); white-space: nowrap; }

@media (max-width: 900px) {
  .card { grid-template-columns: 120px minmax(0, 1fr); }
  .card .strip { grid-column: 1 / -1; }
}
@media (max-width: 640px) {
  .hero { padding: 44px 0 36px; }
  .card { grid-template-columns: 1fr; padding: 20px 20px 20px 24px; }
  .card .cover { width: min(150px, 50%); }
  .hero-grid { grid-template-columns: 1fr; gap: 24px; }
  .hero-cover { width: min(160px, 50%); }
  .chapters a { grid-template-columns: 1fr auto; gap: 2px 12px; }
  .chapters .no { grid-column: 1 / -1; }
  .lb-p, .lb-n { top: auto; bottom: 16px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .cover img, .strip img, .slides a { transition: none; }
}