body{background-color:#1a1a1a;color:#fff;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;margin:0;padding:0}.app-container{max-width:900px;margin:0 auto;padding:40px 20px}.header{position:relative;text-align:center;border-bottom:1px solid #333;padding-bottom:20px;margin-bottom:30px}.header h1{margin:0;font-size:2.5rem;color:#646cff}.logout-btn{position:absolute;right:0;top:50%;transform:translateY(-50%)}.deck-grid{display:grid;grid-template-columns:repeat(auto-fit,250px);justify-content:center;gap:20px;list-style-type:none;padding:0}.deck-card{background-color:#2a2a2a;border:1px solid #444;border-radius:10px;padding:25px;text-align:center;cursor:pointer;transition:all .2s ease-in-out}.deck-card:hover{transform:translateY(-5px);border-color:#646cff;box-shadow:0 5px 15px #646cff33}.deck-card h2{margin:0 0 10px;font-size:1.5rem}.deck-card p{color:#aaa;margin:0;font-size:.9rem}.btn{background-color:#646cff;color:#fff;border:none;padding:10px 20px;border-radius:6px;font-weight:700;cursor:pointer;transition:background-color .2s}.btn:hover{background-color:#535bf2}.btn-danger{background-color:#dc3545}.btn-danger:hover{background-color:#c82333}.login-form{background-color:#2a2a2a;padding:30px;border-radius:10px;max-width:400px;margin:50px auto}input{width:100%;padding:10px;margin:8px 0 20px;border-radius:4px;border:1px solid #555;background-color:#333;color:#fff;box-sizing:border-box}@media screen and (max-width:600px){.header{flex-direction:column;text-align:center;gap:15px;height:auto;padding-bottom:20px}.logout-btn{position:static;width:100%;margin-top:10px}}