body{box-sizing:border-box;background-color:#f5f5f7;justify-content:center;margin:0;padding:24px;font-family:system-ui,-apple-system,Segoe UI,sans-serif;display:flex}#app{text-align:center;background:#1a4329;border-radius:12px;width:fit-content;min-width:400px;padding:24px;position:relative;box-shadow:0 2px 8px #00000014}h1{color:#fff;margin:0 0 12px;font-size:25px}p{color:#fff;margin:0 0 16px;font-size:15px}.hidden{display:none}#board{grid-template-rows:repeat(4,1fr);grid-auto-columns:80px;grid-auto-flow:column;justify-content:center;gap:8px;display:grid}#start-screen label{color:#fff;justify-content:center;display:flex}#start-button{color:#fff;appearance:none;background-color:#b71c1c;border:none;border-radius:20px;margin-top:15px;padding:5px 25px}.card{aspect-ratio:1;cursor:pointer;perspective:600px;background:0 0;border:none;max-width:80px;padding:0}.card-inner{width:100%;height:100%;transform-style:preserve-3d;transition:transform .4s;position:relative}.card:hover{filter:brightness(1.1)}.card.flipped .card-inner{transform:rotateY(180deg)}.card-front,.card-back{backface-visibility:hidden;box-sizing:border-box;border-radius:8px;justify-content:center;align-items:center;width:100%;height:100%;font-size:20px;font-weight:700;display:flex;position:absolute}.card-front{color:#1a1a1a;background-color:#fff;border:3px solid #b71c1c;transform:rotateY(180deg)}.card-back{background-color:#b71c1c;background-image:repeating-linear-gradient(45deg,#8b1414,#8b1414 4px,#b71c1c 4px 8px);border:3px solid #fff}.card.matched .card-front{color:#fff;background-color:#4caf50;border-color:#fff}.select-button{justify-content:center;align-items:center;gap:16px;max-width:340px;margin:30px auto 0;display:flex}#restart{color:#111;cursor:pointer;background-color:#d4af37;border:none;justify-content:center;align-items:center;min-width:100px;padding:8px 1.5rem;font-weight:600;transition:background-color .3s ease-in-out;display:flex}#restart:before{content:"";background-color:currentColor;block-size:1.25em;inline-size:1.25em;margin-inline-end:.3rem;-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M21.5 2v6h-6M21.34 15.57a10 10 0 1 1-.57-8.38'/%3E%3C/svg%3E") 50%/contain no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M21.5 2v6h-6M21.34 15.57a10 10 0 1 1-.57-8.38'/%3E%3C/svg%3E") 50%/contain no-repeat}#change-difficulty{padding:8px 1.5rem}#clear-overlay{background:#0009;border-radius:12px;justify-content:center;align-items:center;animation:.4s fadeIn;display:flex;position:absolute;inset:0}#clear-overlay.hidden{display:none}.clear-box{text-align:center;background:#fff;border-radius:12px;padding:32px 24px;animation:.4s popIn}.clear-box h2{color:#1a1a1a;margin-bottom:12px;font-size:24px}.clear-box p{color:#444;margin:0 0 16px}#clear-restart{color:#111;cursor:pointer;background-color:#d4af37;border:none;justify-content:center;align-items:center;min-width:100px;padding:8px 1.5rem;font-weight:600;transition:background-color .3s ease-in-out;display:flex}#clear-restart:before{content:"";background-color:currentColor;block-size:1.25em;inline-size:1.25em;margin-inline-end:.3rem;-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M21.5 2v6h-6M21.34 15.57a10 10 0 1 1-.57-8.38'/%3E%3C/svg%3E") 50%/contain no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M21.5 2v6h-6M21.34 15.57a10 10 0 1 1-.57-8.38'/%3E%3C/svg%3E") 50%/contain no-repeat}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes popIn{0%{opacity:0;transform:scale(.8)}to{opacity:1;transform:scale(1)}}