:root{font-family:system-ui,-apple-system,'Apple SD Gothic Neo','Malgun Gothic',sans-serif;color:#85601E;background:#FFFDF4;color-scheme:light}*{box-sizing:border-box}body{margin:0}main{max-width:920px;margin:auto;padding:38px 20px 48px}.coupon-page{text-align:center}.brand{font-size:14px;letter-spacing:.13em;font-weight:700;margin:0 0 14px}h1{font-size:clamp(24px,5vw,34px);word-break:keep-all;margin:0 0 12px}p{line-height:1.6}.card{margin:26px auto 0;max-width:840px;filter:drop-shadow(0 15px 18px #85601e15)}canvas{display:block;width:100%;height:auto}.actions{display:flex;justify-content:center;flex-wrap:wrap;gap:12px;margin:25px 0 0}button,.button{font:700 16px system-ui;border:0;border-radius:999px;padding:15px 24px;min-height:50px;cursor:pointer;background:#85601E;color:white;text-decoration:none}button:disabled{opacity:.45;cursor:wait}.secondary{background:#f7d749;color:#614513}.note,.demo{font-size:13px;color:#765b2c}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid #c09924;outline-offset:4px}#saved-image{width:100%;height:auto;display:block;margin:20px 0 0}#error{color:#a13924}label{display:block;font-size:16px;font-weight:650;margin:20px 0 7px}input,textarea{font:16px system-ui;color:#614513;padding:12px;border:1px solid #c6af78;border-radius:10px;width:100%;background:white}textarea{min-height:180px;line-height:1.5}table{width:100%;border-collapse:collapse;font-size:14px}td,th{text-align:left;padding:12px 8px;border-bottom:1px solid #decfa9}td:last-child{overflow-wrap:anywhere}section{margin-top:26px}.scroll{overflow:auto}code{overflow-wrap:anywhere}@media(max-width:500px){main{padding:28px 12px 36px}.actions button{padding:13px 19px;font-size:15px}.note{font-size:12px}.card{margin-top:22px}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}
[hidden]{display:none!important}.envelope-button{position:relative;display:block;width:min(74vw,290px);height:210px;margin:30px auto 14px;border:0;border-radius:0;background:none;filter:drop-shadow(0 14px 17px #85601e25);padding:0;-webkit-tap-highlight-color:transparent}.envelope-button:disabled{opacity:1}.envelope{position:absolute;inset:36px 0 0;perspective:650px}.envelope-back{position:absolute;inset:0;background:#eac765;border-radius:8px}.envelope-letter{position:absolute;left:13%;right:13%;bottom:26px;height:115px;border-radius:6px;background:#FFFDF4;display:grid;place-items:center;font-size:38px;transition:transform .6s ease;z-index:1}.envelope-front{position:absolute;inset:0;background:#F7D749;clip-path:polygon(0 0,50% 55%,100% 0,100% 100%,0 100%);border-radius:8px;z-index:2}.envelope-flap{position:absolute;top:0;left:0;right:0;height:102px;background:#ffe6a0;clip-path:polygon(0 0,100% 0,50% 100%);transform-origin:top;transition:transform .55s ease;z-index:3}.opening .envelope-flap{transform:rotateX(180deg);z-index:0}.opening .envelope-letter{transform:translateY(-75px)}.hint{font-size:14px;font-weight:650}#content.entering{animation:coupon-rise .6s ease both}@keyframes coupon-rise{from{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}