* { box-sizing: border-box; }
:root { color-scheme: dark; --white: #fff; --dim: rgba(255,255,255,.56); --line: rgba(255,255,255,.18); }
html, body { margin: 0; min-width: 320px; min-height: 100%; background: #000; color: #fff; font-family: Arial, Helvetica, sans-serif; }
body { overflow: hidden; }
button, input { font: inherit; }
button { cursor: pointer; }
.is-hidden { display: none !important; }
.seo-heading { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.scene, .intro-screen, .video-stage, .error-screen, .return-screen { min-height: 100vh; width: 100%; }
.scene { position: relative; background: #000; overflow: hidden; }
.intro-screen { display: grid; place-items: center; position: relative; }
.morph-canvas { position: fixed; inset: 0; z-index: 5; width: 100vw; height: 100vh; opacity: 0; pointer-events: none; transition: opacity .25s ease; }
.morph-canvas.is-running { opacity: 1; }
.morph-canvas.is-complete { opacity: 0; }
.start-button { border: 0; background: #fff; color: #000; min-width: 174px; padding: 17px 29px; border-radius: 999px; font-size: 18px; font-weight: 500; letter-spacing: -.02em; transition: transform .35s ease, opacity .35s ease, filter .35s ease; }
.start-button:hover { transform: scale(1.05); }
.start-button.is-transforming { background: transparent; color: #fff; animation: button-shell-fade 1.35s ease forwards; }
.source-letter { display: inline-block; margin: 0 2px; }
.start-button.is-transforming .source-letter { animation: source-letter-break .85s cubic-bezier(.2,.8,.2,1) forwards; }
.start-button.is-transforming .source-letter:nth-child(1) { --dx: -88px; --dy: -48px; --rot: -24deg; animation-delay: 0s; }.start-button.is-transforming .source-letter:nth-child(2) { --dx: -44px; --dy: -70px; --rot: -12deg; animation-delay: .08s; }.start-button.is-transforming .source-letter:nth-child(3) { --dx: 0; --dy: -82px; --rot: 0deg; animation-delay: .16s; }.start-button.is-transforming .source-letter:nth-child(4) { --dx: 46px; --dy: -68px; --rot: 12deg; animation-delay: .24s; }.start-button.is-transforming .source-letter:nth-child(5) { --dx: 90px; --dy: -45px; --rot: 24deg; animation-delay: .32s; }
.birthday-wordmark { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; pointer-events: none; font-size: clamp(34px, 8vw, 90px); font-weight: 500; letter-spacing: -.055em; line-height: .9; }
.birthday-line { display: flex; }
.birthday-letter { display: inline-block; opacity: 0; transform: translateY(30px) scale(.75); }
.birthday-wordmark.is-visible .birthday-letter { animation: birthday-letter-in .72s cubic-bezier(.18,.86,.25,1) forwards; }
.birthday-wordmark.is-visible .birthday-letter:nth-child(2n) { animation-delay: .07s; }.birthday-wordmark.is-visible .birthday-letter:nth-child(3n) { animation-delay: .14s; }.birthday-wordmark.is-visible .birthday-letter:nth-child(4n) { animation-delay: .21s; }
.source-details { position: absolute; bottom: 26px; left: 50%; transform: translateX(-50%); color: rgba(255,255,255,.38); font-size: 11px; letter-spacing: .04em; }
.source-details summary { cursor: pointer; text-align: center; list-style: none; }.source-details summary::-webkit-details-marker { display: none; }.source-details summary::before { content: '＋ '; color: rgba(255,255,255,.65); }
.source-row { display: grid; grid-template-columns: 80px 110px 100px; gap: 9px; align-items: center; margin-top: 11px; white-space: nowrap; }.source-row input { width: 110px; font-size: 10px; }.source-row label { color: rgba(255,255,255,.6); }.source-row span { overflow: hidden; text-overflow: ellipsis; }
.video-stage { position: relative; display: grid; place-items: center; background: #000; }.stage-video { width: 100%; height: 100vh; object-fit: contain; background: #000; }.placeholder-stage { width: min(90vw, 760px); height: min(52vw, 430px); display: grid; place-items: center; align-content: center; gap: 10px; border: 1px solid rgba(255,255,255,.16); background: #000; }.placeholder-number { font-size: clamp(90px, 18vw, 210px); line-height: .8; font-weight: 600; letter-spacing: -.1em; }.placeholder-text { color: var(--dim); font-size: 12px; letter-spacing: .14em; text-transform: uppercase; }.stage-caption, .stage-hint { position: fixed; z-index: 2; font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: rgba(255,255,255,.54); }.stage-caption { top: 24px; left: 28px; }.stage-hint { bottom: 22px; left: 50%; transform: translateX(-50%); }
.error-screen { display: grid; place-items: center; padding: 24px; background: #000; }.error-box { width: min(440px, 100%); display: grid; grid-template-columns: 42px 1fr; gap: 18px; padding: 28px; border: 1px solid var(--line); background: #080808; }.error-mark { width: 42px; height: 42px; border: 1px solid #fff; border-radius: 50%; display: grid; place-items: center; font-size: 21px; }.error-mini, .error-code { color: var(--dim); font-size: 10px; letter-spacing: .12em; }.error-box h1 { margin: 10px 0 10px; font-size: 22px; font-weight: 500; letter-spacing: -.03em; }.error-box p { margin: 0; color: var(--dim); font-size: 13px; line-height: 1.55; }.error-code { margin-top: 18px; }.error-code strong { color: #fff; font-size: 13px; }.ok-button { grid-column: 1 / -1; width: 100%; padding: 13px; border: 0; border-radius: 2px; background: #fff; color: #000; font-size: 13px; font-weight: 600; }.ok-button:hover { background: #ddd; }
.return-screen { display: grid; place-items: center; background: #000; }.return-word { color: rgba(255,255,255,.75); font-size: 12px; letter-spacing: .14em; text-transform: uppercase; animation: blink 1s ease-in-out infinite; }
@keyframes button-shell-fade { 0% { background: #fff; } 35% { background: #fff; } 100% { background: transparent; } }
@keyframes source-letter-break { 0% { opacity: 1; transform: translate(0, 0) rotate(0) scale(1); } 100% { opacity: 0; transform: translate(var(--dx), var(--dy)) rotate(var(--rot)) scale(.55); } }
@keyframes birthday-letter-in { 0% { opacity: 0; transform: translateY(30px) scale(.75); } 65% { opacity: 1; transform: translateY(-4px) scale(1.05); } 100% { opacity: 1; transform: translateY(0) scale(1); } }
@keyframes blink { 0%,100% { opacity: .35; } 50% { opacity: 1; } }
@media (max-width: 560px) { .source-details { bottom: 16px; }.source-row { grid-template-columns: 64px 100px 86px; gap: 5px; font-size: 10px; }.error-box { padding: 22px; } }