:root {
  color-scheme: dark;
  --navy: #0d1530;
  --navy-2: #131d3d;
  --navy-3: #1b2747;
  --line: #2a3760;
  --text: #eef1f8;
  --muted: #a9b3cc;
  --orange: #e8892e;
  --orange-hi: #f4a04b;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--navy);
  color: var(--text);
  font: 17px/1.6 var(--font);
}

.wrap { max-width: 920px; margin: 0 auto; padding: 0 20px; }

a { color: var(--orange-hi); }
a:hover { color: var(--text); }

h1, h2 { line-height: 1.2; letter-spacing: -0.01em; }

/* Hero */
.hero {
  background: linear-gradient(180deg, var(--navy-3) 0%, var(--navy) 100%);
  padding: 40px 0 64px;
  border-bottom: 1px solid var(--line);
}
.brand {
  display: flex; align-items: center; gap: 12px;
  font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; font-size: 14px;
}
.brand img { border-radius: 12px; }
.hero h1 { font-size: clamp(30px, 5.2vw, 50px); margin: 48px 0 20px; max-width: 18em; }
.hero h1 em { font-style: normal; color: var(--orange); }
.lead { font-size: 19px; color: var(--muted); max-width: 40em; margin: 0; }

/* Buttons */
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.btn {
  display: inline-block; padding: 11px 20px; border-radius: 8px;
  border: 1px solid var(--line); background: var(--navy-2);
  color: var(--text); text-decoration: none; font-weight: 600;
}
.btn:hover { border-color: var(--orange); color: var(--text); }
.btn.primary { background: var(--orange); border-color: var(--orange); color: #1a1205; }
.btn.primary:hover { background: var(--orange-hi); border-color: var(--orange-hi); color: #1a1205; }
.btn:focus-visible, .video:focus-visible { outline: 3px solid var(--orange-hi); outline-offset: 3px; }

/* Sections */
section { padding: 64px 0; border-bottom: 1px solid var(--line); }
section h2 { font-size: 30px; margin: 0 0 16px; }
section p { max-width: 42em; }
.note { font-size: 14px; color: var(--muted); margin-top: 8px; }
code {
  font: 0.9em ui-monospace, SFMono-Regular, Menlo, monospace;
  background: var(--navy-3); padding: 2px 6px; border-radius: 4px;
  white-space: nowrap;
}

/* Book */
.book { display: grid; grid-template-columns: 280px 1fr; gap: 48px; align-items: start; }
.cover img {
  width: 100%; height: auto; display: block; border-radius: 6px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}
.title { font-size: 22px; font-weight: 700; margin: 0; }
.subtitle { color: var(--muted); margin: 2px 0 16px; }
.parts {
  list-style: none; padding: 0; margin: 20px 0;
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 6px 20px;
}
.parts li { padding-left: 18px; position: relative; font-size: 15px; }
.parts li::before {
  content: ""; position: absolute; left: 0; top: 0.6em;
  width: 7px; height: 7px; border-radius: 50%; background: var(--orange);
}

/* Video */
.video {
  position: relative; display: block; width: 100%; max-width: 760px;
  aspect-ratio: 16 / 9; padding: 0; margin-top: 8px;
  border: 1px solid var(--line); border-radius: 10px; overflow: hidden;
  background: #000; cursor: pointer;
}
.video img, .video iframe { width: 100%; height: 100%; display: block; object-fit: cover; border: 0; }
.play {
  position: absolute; left: 50%; top: 50%; width: 76px; height: 76px;
  transform: translate(-50%, -50%); border-radius: 50%;
  background: rgba(13, 21, 48, 0.85); border: 2px solid var(--orange);
}
.play::after {
  content: ""; position: absolute; left: 30px; top: 22px;
  border-style: solid; border-width: 16px 0 16px 26px;
  border-color: transparent transparent transparent var(--orange);
}
.video:hover .play { background: var(--orange); }
.video:hover .play::after { border-left-color: var(--navy); }

/* Contact */
.mail { font-size: 22px; font-weight: 600; overflow-wrap: anywhere; }

footer { padding: 32px 0 48px; color: var(--muted); font-size: 14px; }

@media (max-width: 720px) {
  .book { grid-template-columns: 1fr; gap: 32px; }
  .cover { max-width: 220px; }
  .parts { grid-template-columns: 1fr; }
  section { padding: 48px 0; }
  .hero h1 { margin-top: 36px; }
  code { white-space: normal; overflow-wrap: anywhere; }
}