:root {
  color-scheme: dark;
  --canvas: #000000;
  --text: #f5f5f5;
  --muted: #bdbdbd;
  --border: #292929;
  --accent: #e5bd78;
  --accent-hover: #f1cf96;
  --ink: #1b2019;
  --focus: #fff2c6;
  --font: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body { margin: 0; background: var(--canvas); color: var(--text); font-family: var(--font); -webkit-font-smoothing: antialiased; }
button, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
button, a { touch-action: manipulation; }
button { cursor: pointer; }
button:disabled { cursor: wait; }
a { color: inherit; }
button:focus-visible, a:focus-visible, video:focus-visible { outline: 3px solid var(--focus); outline-offset: 5px; }
[hidden] { display: none !important; }
svg { flex-shrink: 0; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.skip-link { position: absolute; z-index: 20; top: 12px; left: 16px; padding: 12px 20px; border-radius: 6px; background: var(--accent); color: var(--ink); transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
.lesson-section { padding: 0 16px; }
.player-area { max-width: 400px; margin: 0 auto; text-align: center; }
.player-frame { width: 100%; aspect-ratio: 9 / 16; position: relative; isolation: isolate; background: #080a08; overflow: hidden; }
video { display: block; width: 100%; height: 100%; object-fit: contain; background: #080a08; }
.start-overlay { position: absolute; inset: 0; width: 100%; padding: 0; border: 0; background: transparent; color: #fff; }
.start-overlay::before { content: ""; position: absolute; inset: 0; background: #0000000d; transition: background .18s ease; }
.start-overlay:hover::before { background: #0002; }
.start-content { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: min(220px, calc(100% - 32px)); padding: 22px 12px; display: flex; flex-direction: column; align-items: center; gap: 8px; border-radius: 8px; background: #000b; }
.play-disc { width: 66px; height: 66px; display: grid; place-items: center; margin-bottom: 7px; border-radius: 50%; color: var(--ink); background: var(--accent); box-shadow: 0 4px 26px #0003; transition: transform .18s ease, background .18s ease; }
.play-disc svg { width: 25px; height: 25px; margin-left: -3px; }
.start-overlay:hover .play-disc { background: var(--accent-hover); transform: scale(1.04); }
.start-content strong { font-size: 20px; line-height: 1.3; font-weight: 600; letter-spacing: -.015em; }
.start-content > span:last-child { font-size: 13px; color: #e6e8e0; }
.sound-note { display: flex; justify-content: center; align-items: center; gap: 8px; font-size: 12px; color: var(--muted); margin: 14px 8px 0; line-height: 1.5; }
.sound-note svg { width: 16px; height: 16px; }
.restart-button { min-height: 44px; padding: 8px 16px; background: transparent; color: var(--text); border: 0; text-decoration: underline; text-underline-offset: 4px; font-size: 13px; }
.player-status { position: absolute; inset: 0; display: flex; gap: 12px; align-items: center; justify-content: center; color: white; background: #0007; font-size: 14px; pointer-events: none; }
.spinner { width: 20px; height: 20px; border: 2px solid #ffffff55; border-top-color: white; border-radius: 50%; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.player-error { position: absolute; inset: 0; padding: 32px; display: flex; flex-direction: column; justify-content: center; align-items: center; background: #101311f5; }
.player-error p { line-height: 1.7; font-size: 16px; }
.retry-button { min-height: 48px; border: 1px solid var(--accent); border-radius: 6px; background: var(--accent); color: var(--ink); padding: 10px 22px; font-weight: 600; }
.offer { max-width: 520px; margin: 36px auto 0; text-align: center; border-top: 1px solid var(--border); padding: 28px 20px 0; }
.offer h2 { font-size: 25px; letter-spacing: -.02em; line-height: 1.25; font-weight: 600; margin: 0 0 12px; }
.offer p { color: var(--muted); font-size: 15px; line-height: 1.7; margin: 0 auto 22px; max-width: 420px; }
.checkout-button { min-height: 58px; padding: 16px 24px; width: 100%; max-width: 420px; margin: 0 auto; display: flex; justify-content: center; align-items: center; gap: 14px; background: var(--accent); color: var(--ink); border-radius: 7px; font-size: 17px; font-weight: 650; text-decoration: none; transition: background .18s ease, transform .18s ease; }
.checkout-button svg { width: 21px; height: 21px; }
.checkout-button:hover { background: var(--accent-hover); transform: translateY(-1px); }
.checkout-button:active { transform: translateY(0); }
.checkout-note { display: flex; justify-content: center; align-items: center; gap: 6px; color: var(--muted); font-size: 11px; line-height: 1.5; margin-top: 13px; }
.checkout-note svg { width: 14px; height: 14px; }
.about-section { max-width: 640px; margin: 72px auto 0; padding: 0 20px; }
.about-inner > h2 { margin: 0 0 22px; text-align: center; font-size: 26px; line-height: 1.2; font-weight: 600; letter-spacing: -.02em; }
.about-photo { display: block; width: 160px; height: 160px; margin: 0 auto 26px; border-radius: 50%; object-fit: cover; object-position: 50% 45%; }
.about-copy > p { color: var(--text); font-size: 16px; line-height: 1.65; margin: 0 0 18px; }
.about-copy strong { font-weight: 600; color: var(--text); }
.about-copy > .about-closing { padding-top: 6px; margin-bottom: 0; }
.site-footer { max-width: 640px; margin: 40px auto 0; padding: 0 20px 32px; text-align: center; font-size: 13px; line-height: 1.6; color: var(--muted); }
.site-footer > span { display: block; }
@media (max-width: 740px) {
  .lesson-section { padding: 0; }
  .about-section { margin-top: 54px; padding: 0 24px; }
  .about-inner > h2 { font-size: 24px; }
  .about-photo { width: 150px; height: 150px; }
  .site-footer { padding-bottom: 28px; }
  .offer { margin-top: 28px; }
  .offer h2 { font-size: 23px; }
  .checkout-note { font-size: 10px; }
}
@media (max-width: 390px) {
  .sound-note { font-size: 11px; gap: 6px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation-duration: 1ms !important; animation-iteration-count: 1 !important; }
}