:root {
  --bg: #0B1B2B;
  --card: #12263A;
  --border: #1E3852;
  --text: #D6E8F5;
  --muted: #7C93A8;
  --lime: #B6E325;
  --cyan: #20B6CB;
  --shadow: 0 30px 80px rgba(0, 0, 0, 0.45);
  --glow: 0 0 0 1px rgba(32, 182, 203, 0.18), 0 40px 120px rgba(32, 182, 203, 0.12);
  color-scheme: dark;
}
:root[data-theme="light"] {
  --bg: #F7F8F4;
  --card: #FFFFFF;
  --border: #E1E5DC;
  --text: #1D211C;
  --muted: #667062;
  --lime: #55780A; /* 5.1:1 against white, so lime text and white-on-lime buttons pass AA */
  --cyan: #14808F;
  --shadow: 0 30px 80px rgba(29, 33, 28, 0.10);
  --glow: 0 0 0 1px rgba(20, 128, 143, 0.14), 0 40px 120px rgba(20, 128, 143, 0.10);
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.35s ease, color 0.35s ease;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; }

.wrap { width: min(1180px, calc(100% - 64px)); margin: 0 auto; }

/* Header */
.top {
  display: flex; align-items: center; justify-content: space-between;
  padding: 28px 0 8px;
}
.brand { display: flex; align-items: center; gap: 14px; }
.brand svg { width: 40px; height: 40px; display: block; }
.brand .word { font-weight: 600; font-size: 20px; letter-spacing: 0.01em; }
.player video a { color: var(--cyan); text-decoration: underline; }
.brand .by { font-size: 12px; color: var(--muted); display: block; margin-top: -2px; letter-spacing: 0.02em; }

.theme-toggle {
  display: inline-flex; align-items: center; gap: 10px;
  background: transparent; border: 1px solid var(--border); color: var(--muted);
  border-radius: 999px; padding: 8px 14px 8px 10px; cursor: pointer;
  font-size: 13px; transition: border-color 0.2s, color 0.2s;
}
.theme-toggle:hover { border-color: var(--cyan); color: var(--text); }
.theme-toggle .pill {
  width: 30px; height: 16px; border-radius: 999px; background: var(--border); position: relative;
  transition: background 0.25s;
}
.theme-toggle .pill::after {
  content: ""; position: absolute; top: 2px; left: 2px; width: 12px; height: 12px; border-radius: 50%;
  background: var(--muted); transition: transform 0.25s, background 0.25s;
}
:root[data-theme="light"] .theme-toggle .pill { background: var(--cyan); }
:root[data-theme="light"] .theme-toggle .pill::after { transform: translateX(14px); background: #fff; }

/* Hero */
.hero { padding: 56px 0 24px; text-align: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 12px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted);
  margin-bottom: 22px;
}
.eyebrow::before, .eyebrow::after { content: ""; width: 28px; height: 1px; background: var(--border); }
h1 {
  font-size: clamp(30px, 3.6vw, 48px); line-height: 1.12; font-weight: 600;
  letter-spacing: -0.02em; margin: 0 0 16px;
}
h1 .em {
  background: linear-gradient(90deg, var(--lime), var(--cyan));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.sub { color: var(--muted); font-size: 18px; margin: 0 auto; max-width: 640px; }

.player {
  margin: 44px auto 0; max-width: 1080px; position: relative;
  border-radius: 20px; padding: 10px;
  background: linear-gradient(160deg, rgba(182, 227, 37, 0.18), rgba(32, 182, 203, 0.22) 60%, transparent);
  box-shadow: var(--glow);
}
.player .frame {
  border-radius: 12px; overflow: hidden; background: #000;
  box-shadow: var(--shadow); border: 1px solid var(--border);
}
.player video { display: block; width: 100%; aspect-ratio: 16 / 9; background: #000; }
.meta {
  display: flex; justify-content: center; gap: 26px; flex-wrap: wrap;
  color: var(--muted); font-size: 13px; margin-top: 18px;
}
.meta span { display: inline-flex; align-items: center; gap: 8px; }
.meta i { width: 5px; height: 5px; border-radius: 50%; background: var(--cyan); display: inline-block; }

/* Sections */
section { padding: 64px 0 0; }
.sec-head { display: flex; align-items: baseline; justify-content: space-between; gap: 20px; margin-bottom: 22px; }
h2 { font-size: 22px; font-weight: 600; letter-spacing: -0.01em; margin: 0; }
.sec-head p { margin: 0; color: var(--muted); font-size: 14px; }

/* Chapters */
.chapters {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px;
}
.chapter {
  display: grid; grid-template-columns: 40px 1fr auto; align-items: center; gap: 16px;
  padding: 14px 18px; border-radius: 12px; text-align: left; cursor: pointer;
  background: var(--card); border: 1px solid var(--border); color: var(--text);
  transition: border-color 0.2s, transform 0.2s, background 0.2s;
}
.chapter:hover { border-color: var(--cyan); transform: translateY(-1px); }
.chapter .n {
  font-size: 12px; font-variant-numeric: tabular-nums; color: var(--muted);
  width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center;
  border: 1px solid var(--border);
}
.chapter .n svg { display: block; }
.chapter .t { font-size: 15px; font-weight: 500; line-height: 1.35; }
.chapter .time { font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }
.chapter.active { border-color: var(--lime); background: color-mix(in srgb, var(--card) 88%, var(--lime) 12%); }
.chapter.active .n { border-color: var(--lime); color: var(--lime); }
.chapter.active .time { color: var(--lime); }
.chapter.active .t { color: var(--text); }

/* Documents */
.docs { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.doc {
  display: flex; flex-direction: column; gap: 14px; padding: 24px;
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  transition: border-color 0.2s, transform 0.2s;
}
.doc:hover { border-color: var(--cyan); transform: translateY(-2px); }
.doc .icon {
  width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center;
  background: linear-gradient(135deg, rgba(182, 227, 37, 0.16), rgba(32, 182, 203, 0.2));
  color: var(--cyan);
}
.doc .kind { font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); }
.doc h3 { margin: 0; font-size: 18px; font-weight: 600; line-height: 1.3; }
.doc p { margin: 0; color: var(--muted); font-size: 14px; flex: 1; }
.doc .actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 6px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 9px 14px; border-radius: 10px;
  font-size: 13px; font-weight: 500; border: 1px solid var(--border); color: var(--text);
  background: transparent; transition: border-color 0.2s, background 0.2s, color 0.2s;
}
.btn:hover { border-color: var(--cyan); }
.btn.primary { background: var(--lime); color: #0B1B2B; border-color: var(--lime); }
.btn.primary:hover { filter: brightness(1.05); }
:root[data-theme="light"] .btn.primary { color: #fff; }

/* Footer */
footer {
  margin-top: 80px; padding: 28px 0 40px; border-top: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  color: var(--muted); font-size: 13px;
}
footer a { color: var(--cyan); }
footer a:hover { text-decoration: underline; }

/* Contact form (the third card) */
.doc.contact p { flex: 0 0 auto; }
.contact-form { display: flex; flex-direction: column; gap: 10px; margin-top: 4px; flex: 1; }
.contact-form .row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.contact-form label { display: flex; flex-direction: column; gap: 5px; font-size: 12px; color: var(--muted); letter-spacing: 0.02em; }
.contact-form input, .contact-form textarea {
  font: inherit; font-size: 14px; color: var(--text); background: var(--bg);
  border: 1px solid var(--border); border-radius: 10px; padding: 9px 11px; width: 100%;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.contact-form textarea { resize: vertical; min-height: 92px; }
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--cyan); box-shadow: 0 0 0 3px rgba(32, 182, 203, 0.18); }
.contact-form .hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
.contact-form .actions { align-items: center; }
.contact-form button[disabled] { opacity: 0.6; cursor: progress; }
.form-status { font-size: 13px; color: var(--muted); }
.form-status.ok { color: var(--lime); }
.form-status.err { color: #F0765B; }

@media (max-width: 860px) {
  .wrap { width: calc(100% - 32px); }
  .chapters, .docs { grid-template-columns: 1fr; }
  .contact-form .row { grid-template-columns: 1fr; }
  .sec-head { flex-direction: column; gap: 4px; align-items: flex-start; }
  .theme-toggle span.lbl { display: none; }
}