body {
    background: #f8f9fa;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Roboto', sans-serif;
}

.card {
    border: none;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    max-width: 450px;
    width: 100%;
}

.card-header {
    background: #fff;
    border-bottom: 1px solid #e9ecef;
    border-radius: 12px 12px 0 0;
    padding: 0;
}

.nav-tabs {
    border-bottom: none;
    justify-content: center;
}

.nav-tabs .nav-link {
    border: none;
    color: #6c757d;
    font-weight: 500;
    padding: 12px 24px;
    border-radius: 0;
    transition: all 0.3s ease;
}

.nav-tabs .nav-link.active {
    background: #007bff;
    color: #fff;
    border-radius: 12px 12px 0 0;
}

.card-body {
    padding: 2rem;
}

.form-label {
    font-weight: 500;
    color: #495057;
    margin-bottom: 0.5rem;
}

.input-group-text {
    background: #f8f9fa;
    border: 1px solid #ced4da;
    color: #6c757d;
}

.form-control {
    border-left: none;
    padding: 0.75rem;
}

.form-control:focus {
    border-color: #007bff;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.input-group:focus-within .input-group-text {
    border-color: #007bff;
}

.btn {
    border-radius: 8px;
    padding: 0.75rem 1rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-primary {
    background: #007bff;
    border: none;
}

.btn-primary:hover {
    background: #0056b3;
    transform: translateY(-1px);
}

.btn-success {
    background: #28a745;
    border: none;
}

.btn-success:hover {
    background: #1e7e34;
    transform: translateY(-1px);
}

.btn-outline-primary {
    border-color: #007bff;
    color: #007bff;
}

.btn-outline-primary:hover {
    background: #007bff;
    color: #fff;
}

.btn-outline-success {
    border-color: #28a745;
    color: #28a745;
}

.btn-outline-success:hover {
    background: #28a745;
    color: #fff;
}

.btn-group .btn {
    border-radius: 6px !important;
    margin: 0 2px;
}