@font-face {
  font-family: "Source Sans 3";
  src: url("../assets/fonts/SourceSans3-Regular.woff2") format("woff2"),
       url("../assets/fonts/SourceSans3-Regular.ttf") format("truetype");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Sans 3";
  src: url("../assets/fonts/SourceSans3-SemiBold.woff2") format("woff2"),
       url("../assets/fonts/SourceSans3-SemiBold.ttf") format("truetype");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Sans 3";
  src: url("../assets/fonts/SourceSans3-Bold.woff2") format("woff2"),
       url("../assets/fonts/SourceSans3-Bold.ttf") format("truetype");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

:root {
  --bg: #0b0d10;
  --bg-elev: #12161c;
  --bg-card: #161b22;
  --border: #243040;
  --text: #f5f5f5;
  --muted: #9aa3ad;
  --orange: #f08a18;
  --orange-dim: #c46e10;
  --cyan: #2ec4d6;
  --cyan-dim: #1a8a98;
  --white: #ffffff;
  --danger: #ff6b6b;
  --radius: 14px;
  --max: 1080px;
  --font: "Source Sans 3", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--cyan); text-decoration: none; }
a:hover { color: var(--orange); text-decoration: underline; }
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.skip {
  position: absolute; left: -9999px; top: auto;
}
.skip:focus {
  left: 1rem; top: 1rem; z-index: 100;
  background: var(--orange); color: #000; padding: .5rem 1rem; border-radius: 8px;
}

.wrap { width: min(100% - 2rem, var(--max)); margin-inline: auto; }

.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(11,13,16,.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; padding: .85rem 0;
}
.brand {
  display: flex; align-items: center; gap: .7rem;
  color: var(--text); text-decoration: none; font-weight: 700;
}
.brand:hover { text-decoration: none; color: var(--text); }
.brand img { width: 40px; height: 40px; }
.brand span { letter-spacing: .02em; }
.brand small {
  display: block; font-weight: 600; font-size: .7rem;
  color: var(--cyan); letter-spacing: .18em;
}
.nav-links {
  display: flex; flex-wrap: wrap; gap: .2rem .9rem;
  list-style: none; margin: 0; padding: 0;
  font-weight: 600; font-size: .95rem;
}
.nav-links a { color: var(--muted); text-decoration: none; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--text); }
.nav-cta {
  background: var(--orange); color: #111 !important;
  padding: .45rem .9rem; border-radius: 999px; font-weight: 700;
}
.nav-cta:hover { background: #ff9d2e; text-decoration: none !important; color: #111 !important; }

.hero {
  padding: 3.5rem 0 2.5rem;
  background:
    radial-gradient(ellipse at 20% 0%, rgba(240,138,24,.18), transparent 50%),
    radial-gradient(ellipse at 90% 20%, rgba(46,196,214,.12), transparent 45%);
}
.hero-grid {
  display: grid; gap: 2rem; align-items: center;
}
@media (min-width: 860px) {
  .hero-grid { grid-template-columns: 1.15fr .85fr; }
}
.kicker {
  color: var(--cyan); font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; font-size: .8rem; margin: 0 0 .6rem;
}
h1, h2, h3 { line-height: 1.2; margin: 0 0 .75rem; }
h1 { font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -.01em; }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: 1.15rem; }
.lead { font-size: 1.15rem; color: var(--muted); max-width: 42rem; }
.accent { color: var(--orange); }
.actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.5rem; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: .4rem; padding: .8rem 1.25rem; border-radius: 999px;
  font-weight: 700; border: 2px solid transparent; cursor: pointer;
  text-decoration: none !important; font-size: 1rem;
}
.btn-primary { background: var(--orange); color: #111 !important; }
.btn-primary:hover { background: #ff9d2e; color: #111 !important; }
.btn-ghost {
  background: transparent; color: var(--text) !important;
  border-color: var(--border);
}
.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan) !important; }
.btn[aria-disabled="true"], .btn.disabled {
  opacity: .55; pointer-events: none; cursor: not-allowed;
}

.section { padding: 3rem 0; }
.section.alt { background: var(--bg-elev); border-block: 1px solid var(--border); }
.section-head { margin-bottom: 1.5rem; }
.muted { color: var(--muted); }
.grid-3 {
  display: grid; gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}
.card h3 { margin-bottom: .4rem; }
.card .icon {
  width: 42px; height: 42px; border-radius: 10px;
  display: grid; place-items: center; margin-bottom: .8rem;
  background: rgba(46,196,214,.12); color: var(--cyan);
  font-weight: 700;
}

.book-hero {
  display: grid; gap: 2rem; align-items: start;
}
@media (min-width: 860px) {
  .book-hero { grid-template-columns: .9fr 1.1fr; }
}
.cover-frame {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1rem;
  box-shadow: 0 20px 60px rgba(0,0,0,.35);
}
.cover-frame img { border-radius: 10px; width: 100%; }
.price-box {
  margin-top: 1.25rem;
  padding: 1rem 1.1rem;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(240,138,24,.15), rgba(46,196,214,.08));
  border: 1px solid rgba(240,138,24,.35);
}
.price {
  display: flex; align-items: baseline; gap: .75rem; flex-wrap: wrap;
}
.price .now { font-size: 2rem; font-weight: 700; color: var(--orange); }
.price .was {
  text-decoration: line-through; color: var(--muted); font-size: 1.1rem;
}
.badge {
  display: inline-block; padding: .2rem .55rem; border-radius: 999px;
  background: rgba(46,196,214,.15); color: var(--cyan);
  font-size: .8rem; font-weight: 700;
}
.checklist { list-style: none; padding: 0; margin: 1rem 0 0; }
.checklist li {
  position: relative; padding-left: 1.6rem; margin: .45rem 0;
}
.checklist li::before {
  content: "✓"; position: absolute; left: 0; color: var(--cyan); font-weight: 700;
}
.toc {
  display: grid; gap: .6rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}
.toc li {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 10px; padding: .75rem .9rem; list-style: none;
}
.toc { padding: 0; margin: 0; }
.toc strong { color: var(--orange); margin-right: .35rem; }

.placeholder {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  color: var(--muted);
  background: rgba(255,255,255,.02);
}

.tools a {
  display: block; padding: .85rem 1rem; margin: .4rem 0;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 10px; color: var(--text); text-decoration: none;
}
.tools a:hover { border-color: var(--cyan); }

.newsletter {
  display: grid; gap: 1rem;
}
@media (min-width: 700px) {
  .newsletter { grid-template-columns: 1.2fr .8fr; align-items: center; }
}
.newsletter form {
  display: flex; flex-wrap: wrap; gap: .5rem;
}
.newsletter input[type="email"] {
  flex: 1 1 180px;
  padding: .8rem 1rem; border-radius: 999px;
  border: 1px solid var(--border); background: var(--bg);
  color: var(--text); font: inherit;
}
.newsletter button { border: none; }

.legal {
  max-width: 720px;
}
.legal h2 { margin-top: 2rem; }
.placeholder-field {
  background: rgba(240,138,24,.12);
  border: 1px dashed var(--orange);
  color: var(--orange);
  padding: 0 .25rem;
  border-radius: 4px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .95em;
}
.note {
  border-left: 3px solid var(--cyan);
  padding: .75rem 1rem;
  background: rgba(46,196,214,.08);
  border-radius: 0 10px 10px 0;
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0 3rem;
  color: var(--muted); font-size: .92rem;
}
.footer-grid {
  display: grid; gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--cyan); }
.site-footer strong { color: var(--text); }

@media (max-width: 640px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column;
    position: absolute; right: 1rem; top: 64px;
    background: var(--bg-elev); border: 1px solid var(--border);
    padding: 1rem; border-radius: 12px; min-width: 200px;
  }
  .menu-btn {
    display: inline-flex; background: transparent; border: 1px solid var(--border);
    color: var(--text); border-radius: 8px; padding: .4rem .6rem; font: inherit;
  }
}
@media (min-width: 641px) {
  .menu-btn { display: none; }
}