/* Refine only the opening; preserve the client's original design in this demo. */
.envelope{perspective:1100px;filter:drop-shadow(0 18px 22px #061d2830)}
.envelope-flap{transition:transform .65s cubic-bezier(.25,.05,.2,1) .15s;transform-origin:top}
.wax-seal{transition:transform .3s,opacity .25s;box-shadow:inset 0 0 0 4px #ffffff18,0 5px 12px #08251d40}
.letter{transition:transform .65s cubic-bezier(.2,.7,.2,1) .45s;border:1px solid #bba373;outline:1px solid #d8c293;outline-offset:-8px}
.envelope-intro.opening .wax-seal{transform:translateY(15px) rotate(14deg) scale(1.15);opacity:0}
.envelope-intro.opening .envelope-flap{transform:rotateX(-180deg)}
.intro-button:focus-visible{outline:3px solid #f5df9f;outline-offset:6px}
@media(prefers-reduced-motion:reduce){.envelope-flap,.wax-seal,.letter,.envelope-intro{transition:none!important}.envelope-intro.opening .letter{transform:none}}