body {
    background: #f8f9fa;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.signup-container {
    width: 100%;
    padding: 15px;
}

.signup-box {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    max-width: 450px;
    margin: 0 auto;
}

.signup-box .bi-person-plus {
    color: #0d6efd;
    margin-bottom: 1rem;
}

.input-group-text {
    background: transparent;
}

.form-control:focus {
    box-shadow: none;
    border-color: #0d6efd;
}

.btn-primary {
    padding: 0.8rem;
}

.btn-outline-secondary {
    border-color: #ced4da;
}

.btn-outline-secondary:hover {
    background-color: #f8f9fa;
    color: #0d6efd;
    border-color: #ced4da;
}

/* Password strength indicator */
.password-strength {
    height: 5px;
    margin-top: 5px;
    border-radius: 3px;
    transition: all 0.3s ease;
}

.strength-weak {
    background-color: #dc3545;
    width: 30%;
}

.strength-medium {
    background-color: #ffc107;
    width: 60%;
}

.strength-strong {
    background-color: #198754;
    width: 100%;
}

/* Error message styling */
.error-message {
    color: #dc3545;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* Shake animation */
@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

.shake {
    animation: shake 0.5s;
}