:root {
    --primary-color: #0d6efd;
    --secondary-color: #6c757d;
    --success-color: #198754;
    --error-color: #dc3545;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0;
    padding: 20px;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

.login-container {
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
    padding: 2rem;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    color: var(--primary-color);
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.nav-tabs {
    margin-bottom: 1.5rem;
}

.nav-tabs .nav-link {
    color: var(--secondary-color);
    border: none;
    border-bottom: 2px solid transparent;
    padding: 0.75rem 1rem;
    transition: all 0.3s ease;
}

.nav-tabs .nav-link.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    background: none;
}

.form-floating {
    margin-bottom: 1rem;
}

.form-floating > .form-control {
    padding: 1rem 0.75rem;
}

.form-floating > label {
    padding: 1rem 0.75rem;
}

.btn-login {
    width: 100%;
    padding: 0.75rem;
    font-size: 1rem;
    font-weight: 500;
    margin-top: 1rem;
    background-color: var(--primary-color);
    border: none;
    transition: all 0.3s ease;
}

.btn-login:hover {
    background-color: #0b5ed7;
    transform: translateY(-1px);
}

.alert {
    margin-bottom: 1rem;
    padding: 0.75rem;
    border-radius: 8px;
    font-size: 0.9rem;
}

.alert-danger {
    background-color: #fff5f5;
    color: var(--error-color);
    border: 1px solid #fecdd3;
}

@media (max-width: 576px) {
    .login-container {
        margin: 1rem;
        padding: 1.5rem;
    }
}