:root {
    --altair-red: #D32F2F;
    --altair-navy: #0f172a; /* Deep Slate Navy */
}
body { 
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; 
    overflow-x: hidden; 
    background-color: #f8f9fa;
}

/* Button & Text Utilities */
.bg-altair-navy { background-color: var(--altair-navy) !important; }
.text-altair-navy { color: var(--altair-navy) !important; }
.btn-altair-red { background-color: var(--altair-red); color: white; font-weight: bold; border: none;}
.btn-altair-red:hover { background-color: #B71C1C; color: white; }

/* Sidebar Layout Architecture */
#wrapper { display: flex; height: 100vh; overflow: hidden; }
#sidebar-wrapper { width: 280px; flex-shrink: 0; display: flex; flex-direction: column; z-index: 1000; box-shadow: 2px 0 10px rgba(0,0,0,0.3); }
#page-content-wrapper { flex-grow: 1; display: flex; flex-direction: column; overflow: hidden; background-color: #f9fafb;}
#main-scrollable-area { overflow-y: auto; flex-grow: 1; padding: 2rem; }

/* Sidebar Links */
.sidebar-link {
    color: #94a3b8;
    padding: 12px 20px;
    display: flex;
    align-items: center;
    text-decoration: none;
    transition: 0.2s;
    border-radius: 8px;
    margin: 4px 16px;
    font-size: 0.9rem;
    font-weight: 500;
}
.sidebar-link:hover, .sidebar-link.active {
    background-color: var(--altair-red);
    color: white;
    text-decoration: none;
}
.sidebar-link i { width: 24px; font-size: 1.1rem; }

/* Dashboard Cards */
.card-kpi { border-radius: 12px; border: 1px solid #e2e8f0; box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05); }
.card-kpi-red { border-top: 4px solid var(--altair-red); }
.card-kpi-navy { border-top: 4px solid #1e293b; }
.card-kpi-blue { border-top: 4px solid #3b82f6; }
.card-kpi-green { border-top: 4px solid #10b981; }