/* Modern Simple CSS for Registration Page */

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    --light-color: #f8fafc;
    --dark-color: #1f2937;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --border-radius: 0.5rem;
    --box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --box-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --transition: all 0.2s ease-in-out;
}

/* Global Styles */
* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.5;
    color: var(--gray-800);
    background-color: #ffffff;
    margin: 0;
    padding: 0;
}

/* Card Styles */
.card {
    background: #ffffff;
    border: 1px solid var(--gray-200);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow-lg);
    transition: var(--transition);
}

.card:hover {
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* Form Styles */
.form-control {
    border: 1px solid var(--gray-300);
    border-radius: var(--border-radius);
    padding: 0.75rem 1rem;
    font-size: 1rem;
    transition: var(--transition);
    background: #ffffff;
    color: var(--gray-800);
}

.form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
    outline: none;
}

.form-control.is-invalid {
    border-color: var(--danger-color);
    background: #fef2f2;
}

.form-control.is-valid {
    border-color: var(--success-color);
    background: #f0fdf4;
}

/* Label Styles */
.form-label {
    color: var(--dark-color);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

/* Button Styles */
.btn-primary {
    background: var(--primary-color);
    border: 1px solid var(--primary-color);
    border-radius: var(--border-radius);
    padding: 0.75rem 1.5rem;
    font-weight: 500;
    color: #ffffff;
    transition: var(--transition);
}

.btn-primary:hover {
    background: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--box-shadow-lg);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Input Group Styles */
.input-group .btn {
    border: 1px solid var(--gray-300);
    border-left: none;
    background: #ffffff;
    color: var(--gray-600);
    transition: var(--transition);
}

.input-group .btn:hover {
    background: var(--gray-100);
    color: var(--primary-color);
}

.input-group .form-control:focus + .btn {
    border-color: var(--primary-color);
}

/* Alert Styles */
.alert {
    border: 1px solid;
    border-radius: var(--border-radius);
    padding: 1rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.alert-success {
    background: #f0fdf4;
    color: #166534;
    border-color: #bbf7d0;
}

.alert-danger {
    background: #fef2f2;
    color: #991b1b;
    border-color: #fecaca;
}

.alert-warning {
    background: #fffbeb;
    color: #92400e;
    border-color: #fed7aa;
}

.alert-info {
    background: #eff6ff;
    color: #1e40af;
    border-color: #bfdbfe;
}

/* Loading Spinner */
.spinner-border-sm {
    width: 1rem;
    height: 1rem;
}

/* Form Text */
.form-text {
    font-size: 0.875rem;
    margin-top: 0.25rem;
    color: var(--gray-500);
}

/* Responsive Design */
@media (max-width: 768px) {
    .card-body {
        padding: 2rem 1.5rem;
    }
}

@media (max-width: 576px) {
    .card-body {
        padding: 1.5rem 1rem;
    }
    
    .container {
        padding: 0 1rem;
    }
}

/* Focus styles for accessibility */
.form-control:focus,
.btn:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}