:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #dbeafe;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

/* Navbar tweaks */
.navbar-dark .navbar-nav .nav-link {
    color: rgba(255,255,255,0.85);
    transition: color .15s;
}
.navbar-dark .navbar-nav .nav-link:hover,
.navbar-dark .navbar-nav .nav-link.active {
    color: #fff;
}

/* Card hover */
.card.shadow-sm {
    transition: box-shadow .2s;
}
.card.shadow-sm:hover {
    box-shadow: 0 .25rem 1rem rgba(0,0,0,0.08) !important;
}

/* List group item */
.list-group-item {
    transition: background-color .15s;
}
.list-group-item:hover {
    background-color: #f8fafc;
}

/* Done item */
.todo-done .todo-title {
    text-decoration: line-through;
    opacity: .6;
}

/* Overdue */
.overdue-item {
    background-color: #fef2f2;
}

/* Checkbox */
.form-check-input-lg {
    width: 1.25rem;
    height: 1.25rem;
    cursor: pointer;
}

/* Spinner overlay */
.spinner-overlay {
    position: fixed;
    inset: 0;
    background: rgba(255,255,255,0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

/* Print styles */
@media print {
    .navbar, .btn, .card-header .btn, .nav-tabs,
    button[onclick="window.print()"] {
        display: none !important;
    }
    .card {
        border: 1px solid #ddd !important;
        box-shadow: none !important;
    }
    body {
        background: white;
    }
}

/* Empty state */
.empty-state {
    padding: 3rem 1rem;
    text-align: center;
    color: #94a3b8;
}
.empty-state i {
    font-size: 3rem;
    margin-bottom: .5rem;
    opacity: .5;
}

/* Responsive tweaks */
@media (max-width: 576px) {
    .h3 { font-size: 1.25rem; }
    .card-body { padding: .75rem; }
}