:root{--primary: #f0f0f0;--accent: #ffeb3b;--bg: #121212;--card-bg: rgba(255, 255, 255, .05);--text: #ffffff}*{box-sizing:border-box;margin:0;padding:0;font-family:Pretendard,-apple-system,BlinkMacSystemFont,system-ui,Roboto,sans-serif}body{background:var(--bg);color:var(--text);min-height:100vh;display:flex;justify-content:center;align-items:center;overflow-x:hidden}#root{width:100%;max-width:600px;padding:20px}.game-container{background:rgba(40,40,40,.6);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-radius:32px;padding:40px;box-shadow:0 30px 60px #000000b3;text-align:center;border:1px solid rgba(255,255,255,.1)}h1{font-size:2rem;margin-bottom:24px;color:var(--primary);letter-spacing:-1px}.difficulty-selector{display:flex;justify-content:center;gap:12px;margin-bottom:32px;flex-wrap:wrap}.btn{padding:12px 24px;border:none;border-radius:16px;background:rgba(255,255,255,.1);color:#fff;cursor:pointer;transition:all .4s cubic-bezier(.175,.885,.32,1.275);font-weight:600;font-size:.95rem}.btn:hover{background:rgba(255,255,255,.15);transform:scale(1.05)}.btn.active{background:var(--primary);color:#000;box-shadow:0 4px 20px #ffffff4d}.puzzle-board{display:grid;gap:6px;background:rgba(255,255,255,.02);padding:10px;border-radius:20px;position:relative;aspect-ratio:1 / 1;margin:0 auto;max-width:480px;box-shadow:inset 0 0 30px #000c}.tile{background-repeat:no-repeat;cursor:pointer;border-radius:12px;transition:all .25s cubic-bezier(.4,0,.2,1);border:1px solid rgba(255,255,255,.03)}.tile:hover{filter:brightness(1.15);z-index:2;transform:translateY(-2px)}.tile.empty{background:rgba(0,0,0,.3)!important;cursor:default;border:none}.stats{margin:24px 0;display:flex;justify-content:space-around;font-size:1.1rem;color:#aaa}.controls{margin-top:24px;display:flex;gap:12px;justify-content:center}.overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.9);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);display:flex;justify-content:center;align-items:center;z-index:1000;animation:fadeIn .4s ease}.modal{background:#1e1e1e;padding:30px;border-radius:28px;max-width:90%;width:500px;box-shadow:0 50px 100px #000;border:1px solid rgba(255,255,255,.1);text-align:center}.modal-image{width:100%;border-radius:20px;margin-bottom:24px;box-shadow:0 0 40px #ffffff1a}.success-text{font-size:2.2rem;margin-bottom:10px;background:linear-gradient(45deg,#fff,#ffeb3b);-webkit-background-clip:text;-webkit-text-fill-color:transparent}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@media (max-width: 480px){.game-container{padding:20px}h1{font-size:1.5rem}.btn{padding:8px 16px;font-size:.85rem}}