/* Custom CSS for Simple Messaging App */

/* ===== BASE STYLES ===== */

/* This ensures consistent box-sizing across all elements */
* {
    box-sizing: border-box;
}

/* ===== ANIMATIONS ===== */

/* Fade in animation for smooth transitions */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Slide in animation for forms */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* ===== UTILITY CLASSES ===== */

/* Apply fade in animation to elements */
.fade-in {
    animation: fadeIn 0.3s ease-out;
}

/* Apply slide in animation to forms */
.slide-in {
    animation: slideIn 0.3s ease-out;
}

/* Smooth transitions for hover effects */
.transition-all {
    transition: all 0.2s ease-in-out;
}

/* ===== MESSAGE STYLES ===== */

/* Style for individual message cards */
.message-card {
    border-left: 4px solid #3b82f6; /* Blue left border */
    transition: all 0.2s ease-in-out;
}

.message-card:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* Style for unread messages */
.message-unread {
    border-left-color: #ef4444; /* Red border for unread */
    background-color: #fef2f2; /* Light red background */
}

/* ===== FORM STYLES ===== */

/* Focus styles for form inputs */
.form-input:focus {
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* Error state for form inputs */
.form-input-error {
    border-color: #ef4444;
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

/* ===== ALERT STYLES ===== */

/* Base alert styling */
.alert {
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    animation: slideIn 0.3s ease-out;
}

/* Success alert (green) */
.alert-success {
    background-color: #dcfce7;
    border: 1px solid #16a34a;
    color: #15803d;
}

/* Error alert (red) */
.alert-error {
    background-color: #fef2f2;
    border: 1px solid #ef4444;
    color: #dc2626;
}

/* Warning alert (yellow) */
.alert-warning {
    background-color: #fef3c7;
    border: 1px solid #f59e0b;
    color: #d97706;
}

/* Info alert (blue) */
.alert-info {
    background-color: #dbeafe;
    border: 1px solid #3b82f6;
    color: #1d4ed8;
}

/* ===== LOADING STATES ===== */

/* Loading spinner */
.loading-spinner {
    border: 2px solid #f3f4f6;
    border-top: 2px solid #3b82f6;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* ===== RESPONSIVE DESIGN ===== */

/* Mobile-first responsive design */
@media (max-width: 768px) {
    /* Stack navigation vertically on mobile */
    .nav-mobile {
        flex-direction: column;
        gap: 1rem;
    }
    
    /* Full width buttons on mobile */
    .btn-mobile {
        width: 100%;
    }
    
    /* Reduce padding on mobile */
    .mobile-padding {
        padding: 1rem;
    }
}

/* ===== ACCESSIBILITY ===== */

/* Focus indicators for keyboard navigation */
.focus-visible:focus {
    outline: 2px solid #3b82f6;
    outline-offset: 2px;
}

/* Screen reader only text */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== CUSTOM COMPONENTS ===== */

/* Message timestamp styling */
.message-timestamp {
    font-size: 0.75rem;
    color: #6b7280;
    font-style: italic;
}

/* Message subject styling */
.message-subject {
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

/* Message body styling */
.message-body {
    color: #4b5563;
    line-height: 1.5;
}

/* Empty state styling */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: #6b7280;
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}