/* youtube.dmchang.xyz — the Chinstein channel's sign-up page.
   Rules: Documents/code/design-skills/elayadesign_ai-design-skills/skills/landing-page-design/SKILL.md (Tailwind type scale,
   spacing tokens 2..96 px, flat dark backgrounds, one accent, Geist only, custom easing, no hyphens in copy). */
:root {
  --bg: #000000; --surface: #181818; --line: #272727; --line-2: #313131;
  --text: #f2f1ec; --muted: #9b9b9b; --faint: #6b6b6b;
  --accent: #ff6a2a; --good: #7cc08a; --bad: #d9697c;
  --ease: cubic-bezier(0.32, 0.72, 0, 1);
  --sans: "Geist", ui-sans-serif, system-ui, sans-serif; --mono: "Geist Mono", ui-monospace, monospace;
}
* { box-sizing: border-box; }
html { background: var(--bg); color-scheme: dark; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: var(--sans); font-size: 16px; line-height: 24px;
  -webkit-font-smoothing: antialiased; }
a { color: inherit; }
h1, h2, p { margin: 0; }
h1, h2 { text-wrap: balance; } p { text-wrap: pretty; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
.skip { position: absolute; left: 16px; top: -48px; padding: 8px 12px; background: var(--text); color: var(--bg); border-radius: 8px;
  text-decoration: none; font-weight: 600; transition: top 300ms var(--ease); z-index: 10; }
.skip:focus { top: 16px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* header */
.top { max-width: 1040px; margin: 0 auto; padding: 24px; display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 8px; font-weight: 600; font-size: 16px; text-decoration: none; }
.dot { width: 12px; height: 12px; border-radius: 9999px; background: var(--accent); }
.quiet { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 14px; line-height: 20px; font-weight: 500;
  text-decoration: none; padding: 8px 12px; border-radius: 9999px; transition: color 300ms var(--ease), background 300ms var(--ease); }
.quiet:hover { color: var(--text); background: var(--surface); }
.quiet i { font-size: 20px; }

main { max-width: 1040px; margin: 0 auto; padding: 0 24px; }

/* hero */
.hero { padding: 96px 0 64px; display: flex; flex-direction: column; align-items: center; text-align: center; gap: 24px; }
.hero h1 { max-width: 680px; font-size: 72px; line-height: 1; font-weight: 600; letter-spacing: -0.03em;
  background: linear-gradient(90deg, #ffffff, #9b9b9b); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sub { max-width: 680px; font-size: 20px; line-height: 28px; color: var(--muted); }
.fine { font-size: 14px; line-height: 20px; color: var(--faint); }

/* sign-up */
.signup { position: relative; display: flex; gap: 8px; width: 100%; max-width: 480px; padding: 8px; background: var(--surface);
  border: 1px solid var(--line); border-radius: 16px; transition: border-color 300ms var(--ease); }
.signup:focus-within { border-color: var(--line-2); }
.signup input { flex: 1; min-width: 0; background: transparent; border: 0; color: var(--text); font: inherit; font-size: 16px;
  padding: 8px 12px; border-radius: 8px; outline: none; }
.signup input::placeholder { color: var(--faint); }
.signup button { display: flex; align-items: center; gap: 8px; border: 0; cursor: pointer; background: var(--accent); color: #000000;
  font: inherit; font-size: 16px; font-weight: 600; padding: 8px 12px; border-radius: 8px; white-space: nowrap;
  transition: transform 300ms var(--ease), background 300ms var(--ease); }
.signup button:hover { background: #ff7d45; }
.signup button:active { transform: scale(0.98); }
.signup button i { font-size: 16px; transition: transform 300ms var(--ease); }
.signup button:hover i { transform: translateX(2px); }
.signup[aria-busy="true"] button { opacity: 0.6; pointer-events: none; }
.msg { position: absolute; left: 12px; right: 12px; top: calc(100% + 8px); font-size: 14px; line-height: 20px; text-align: left; min-height: 20px; }
.msg:empty { display: none; }
.msg.err { color: var(--bad); } .msg.ok { color: var(--good); }
.signup.done input, .signup.done button { display: none; }
.signup.done { justify-content: center; }
.signup.done .msg { position: static; text-align: center; padding: 8px 12px; font-size: 16px; line-height: 24px; color: var(--text); }

/* proof */
.proof { display: grid; grid-template-columns: 3fr 2fr; gap: 32px; align-items: center; padding: 48px 0 96px; }
.video { display: flex; flex-direction: column; gap: 12px; text-decoration: none; }
.frame { display: block; border-radius: 16px; overflow: hidden; border: 1px solid var(--line);
  transition: transform 700ms var(--ease), border-color 300ms var(--ease); }
.frame img { display: block; width: 100%; height: auto; }
.video:hover .frame { transform: scale(1.01); border-color: var(--line-2); }
.video:active .frame { transform: scale(0.98); }
.play { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 14px; line-height: 20px; font-weight: 600;
  transition: color 300ms var(--ease); }
.video:hover .play { color: var(--text); }
.play i { color: var(--accent); font-size: 16px; }
.numbers { display: flex; flex-direction: column; gap: 16px; }
.numbers p { color: var(--muted); font-size: 18px; line-height: 28px; }
.row { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; padding-top: 16px; border-top: 1px solid var(--line); }
.label { color: var(--muted); font-size: 14px; line-height: 20px; }
.num { font-family: var(--mono); font-size: 36px; line-height: 40px; font-weight: 500; letter-spacing: -0.02em; }
.num.bad { color: var(--bad); } .num.good { color: var(--good); }

/* tagline: each word lights up as it scrolls past */
.tagline { padding: 96px 0; display: flex; justify-content: center; }
.words { max-width: 680px; font-size: 60px; line-height: 1; font-weight: 600; letter-spacing: -0.03em; text-align: center; text-wrap: balance; }
.words span { color: rgba(242, 241, 236, 0.3); transition: color 700ms var(--ease); }
.words span.on { color: var(--text); }

/* how it works */
.steps ol { list-style: none; margin: 0; padding: 0 0 96px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.steps li { display: flex; flex-direction: column; gap: 12px; }
.steps i { font-size: 32px; color: var(--accent); }
.steps h2 { font-size: 20px; line-height: 28px; font-weight: 600; }
.steps p { color: var(--muted); }

/* faq */
.faq { max-width: 680px; margin: 0 auto; padding-bottom: 96px; }
.faq details { border-top: 1px solid var(--line); }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 16px;
  padding: 24px 0; font-size: 18px; line-height: 28px; font-weight: 500; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-size: 24px; line-height: 32px; transition: transform 300ms var(--ease); }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { color: var(--muted); padding-bottom: 24px; }

/* final */
.final { display: flex; flex-direction: column; align-items: center; gap: 24px; padding: 64px 0 96px; text-align: center; }
.final h2 { font-size: 48px; line-height: 1; font-weight: 600; letter-spacing: -0.03em; }

/* footer */
.foot { max-width: 1040px; margin: 0 auto; padding: 32px 24px 48px; display: flex; gap: 24px; align-items: center; justify-content: center;
  flex-wrap: wrap; color: var(--faint); font-size: 14px; line-height: 20px; border-top: 1px solid var(--line); }
.foot a { display: flex; align-items: center; gap: 8px; text-decoration: none; transition: color 300ms var(--ease); }
.foot a:hover { color: var(--text); }

/* scroll reveal: a heavy fade up */
.js .reveal { opacity: 0; transform: translateY(64px); filter: blur(12px);
  transition: opacity 800ms var(--ease), transform 800ms var(--ease), filter 800ms var(--ease); }
.js .reveal.in { opacity: 1; transform: none; filter: none; }
@media (prefers-reduced-motion: reduce) {
  .js .reveal { opacity: 1; transform: none; filter: none; transition: none; }
  .words span { transition: none; }
}

/* phone */
@media (max-width: 760px) {
  .hero { padding: 64px 0 48px; }
  .hero h1 { font-size: 36px; line-height: 40px; }
  .sub { font-size: 18px; line-height: 28px; }
  .proof { grid-template-columns: 1fr; padding: 32px 0 64px; }
  .words { font-size: 36px; line-height: 40px; }
  .tagline { padding: 64px 0; }
  .steps ol { grid-template-columns: 1fr; gap: 32px; padding-bottom: 64px; }
  .final h2 { font-size: 36px; line-height: 40px; }
  .signup { flex-direction: column; }
  .signup button { justify-content: center; padding: 12px; }
  .msg { position: static; }
}

/* privacy / 404 */
.legal { max-width: 680px; padding: 64px 24px 96px; }
.legal h1 { font-size: 48px; line-height: 1; font-weight: 600; letter-spacing: -0.03em; }
.legal .updated { color: var(--faint); font-size: 14px; line-height: 20px; margin: 16px 0 48px; }
.legal h2 { font-size: 20px; line-height: 28px; font-weight: 600; margin: 40px 0 12px; }
.legal p { color: var(--muted); }
.legal p a { color: var(--text); text-underline-offset: 4px; }
.back { display: inline-flex; align-items: center; gap: 8px; margin-top: 48px; color: var(--text); font-weight: 600; text-decoration: none;
  padding: 8px 12px; border-radius: 8px; background: var(--surface); border: 1px solid var(--line); transition: transform 300ms var(--ease); }
.back:active { transform: scale(0.98); }