.index-container{max-width:400px;margin:4rem auto;padding:2rem;background:#fff;border-radius:8px;box-shadow:0 2px 10px rgba(0,0,0,.1)}.index-header{text-align:center;margin-bottom:2rem}.index-header h1{margin-bottom:.5rem}.code-label{display:block;margin-bottom:.5rem;font-weight:500;color:#333}.code-input{width:100%;padding:.75rem;font-size:1.2rem;letter-spacing:.15em;text-transform:uppercase;text-align:center;border:1px solid #ccc;border-radius:4px;box-sizing:border-box;margin-bottom:1rem}.code-input:focus{outline:0;border-color:#4a90e2;box-shadow:0 0 0 2px rgba(74,144,226,.2)}.join-btn{width:100%;padding:.75rem;font-size:1rem;font-weight:600;color:#fff;background:linear-gradient(135deg,#4a90e2 0,#357abd 100%);border:none;border-radius:4px;cursor:pointer;transition:all .2s ease}.join-btn:hover{background:linear-gradient(135deg,#357abd 0,#2a5f8f 100%);transform:translateY(-1px)}.error-message{background:#fee;border:1px solid #fcc;color:#c33;padding:.75rem;border-radius:4px;margin-bottom:1rem;text-align:center;display:none}.error-message.show{display:block}.admin-link{text-align:center;margin-top:1.5rem;padding-top:1.5rem;border-top:1px solid #eee}.admin-link a{color:#666;font-size:.9rem}.admin-link a:hover{color:#4a90e2}