body { 
    margin: 0; 
    font-family: Arial, sans-serif; 
    display: flex; 
    background: #f8fafc; /* Neutral light bg for readability */
    color: #1e293b; /* Dark text */
}
#site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    background: #1e3a8a; /* Primary blue for header */
    z-index: 10;
    padding: 0;
    box-sizing: border-box;
}
#logo {
    height: 40px; /* Compact for header fit */
    width: auto;
    padding: 10px 20px;
    display: block;
    float: left; /* Left-align in header */
    filter: drop-shadow(0 0 3px rgba(255, 255, 255, 0.8)); /* White glow for contrast on dark bg */
}
#sidebar { 
    position: fixed;
    top: 60px; /* Below header */
    width: 200px; 
    background: #1e3a8a; /* Primary for sidebar */
    color: white; 
    transition: width 0.3s; 
    height: calc(100vh - 60px); /* Full height minus header */
    overflow-y: auto; 
    z-index: 5; /* Below header */
}
#sidebar.collapsed { 
    width: 50px; 
}
#sidebar ul { 
    list-style: none; 
    padding: 20px 0; 
    margin: 0; 
}
#sidebar li a { 
    color: white; 
    text-decoration: none; 
    padding: 10px 15px; 
    display: block; 
    white-space: nowrap; 
    transition: padding 0.3s, visibility 0.3s, background 0.3s; 
}
#sidebar li a:hover { 
    background: #3b82f6; /* Secondary blue hover */
}
#sidebar.collapsed li a { 
    visibility: hidden; 
    padding: 10px 0; 
}
#sidebar.collapsed li a:hover { 
    visibility: visible; 
    padding: 10px 15px; 
    background: #3b82f6; /* Secondary on hover */
}
#toggle-nav { 
    background: none; 
    border: none; 
    color: white; 
    font-size: 20px; 
    width: 100%; 
    padding: 10px; 
    cursor: pointer; 
    transition: background 0.3s; 
    display: block; /* Full-width button */
}
#toggle-nav:hover { 
    background: #3b82f6; /* Secondary hover */
}
#main-content { 
    margin-left: 200px; 
    margin-top: 60px; /* Clear header */
    padding: 20px; 
    flex: 1; 
    min-height: calc(100vh - 60px); 
    background: #f8fafc; /* Neutral body */
    border-left: 1px solid #e2e8f0; /* Subtle divider */
}
#sidebar.collapsed ~ #main-content { 
    margin-left: 50px; 
}
h1, h2 {
    color: #1e293b; /* Dark headings */
}
@media (max-width: 1280px) { 
    body { zoom: 0.8; } /* Scale for smaller laptops */
}
/* Modular accent for future (e.g., Dashboard win rate) */
.success-accent {
    color: #10b981; /* Green for positive metrics */
    font-weight: bold;
}
/* Engineers Module */
#engineers-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    background: white;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}
#engineers-table th, #engineers-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0; /* Light neutral */
}
#engineers-table th {
    background: #1e3a8a; /* Primary */
    color: white;
}
#engineers-table tr:hover {
    background: #f8fafc; /* Neutral bg */
}
.btn-primary, .btn-secondary {
    padding: 8px 16px;
    border: none;
    cursor: pointer;
    border-radius: 4px;
    font-weight: bold;
}
.btn-primary {
    background: #1e3a8a; /* Primary */
    color: white;
}
.btn-primary:hover {
    background: #3b82f6; /* Secondary */
}
.btn-secondary {
    background: #e2e8f0; /* Light neutral */
    color: #1e293b; /* Neutral text */
}
.btn-secondary:hover {
    background: #cbd5e1;
}
#new-engineer {
    float: right;
    margin-bottom: 10px;
}
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 100;
    justify-content: center;
    align-items: center;
}
.modal-content {
    background: white;
    padding: 20px;
    border-radius: 8px;
    width: 400px;
    max-width: 90%;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}
.modal-content h2 {
    color: #1e293b; /* Neutral text */
    margin-top: 0;
}
.modal-content label {
    display: block;
    margin: 10px 0;
    color: #1e293b;
}
.modal-content input {
    width: 100%;
    padding: 8px;
    border: 1px solid #e2e8f0;
    border-radius: 4px;
    box-sizing: border-box;
}
.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 20px;
}
#engineer-modal {
    display: none; /* Hidden by default */
}