:root {
    --primary-color: #003051;
    --secondary-color: #004a7c;
    --accent-color: #00609c; /* Slightly lighter for hover states */
    --light-bg: #f4f6f9;
    --text-color: #333;
    --white: #ffffff;
    --border-color: #dee2e6;
    --success: #28a745;
    --warning: #ffc107;
    --danger: #dc3545;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--light-bg);
    margin: 0;
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header / Navbar */
.navbar {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 15px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--white);
    text-decoration: none;
}

.navbar-brand img {
    height: 40px;
    background: white; /* Ensure visibility if transparent */
    padding: 5px;
    border-radius: 4px;
}

.nav-links a {
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    margin-left: 20px;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--white);
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
    flex: 1;
}

/* Cards */
.card {
    background: var(--white);
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
}

.card-header {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--light-bg);
    padding-bottom: 0.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--white);
    border-left: 5px solid var(--secondary-color);
    padding: 1.5rem;
    border-radius: 4px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.stat-card h3 {
    margin: 0;
    font-size: 2rem;
    color: var(--primary-color);
}

.stat-card p {
    margin: 0.5rem 0 0;
    color: #666;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--secondary-color);
    color: var(--white);
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    text-decoration: none;
    transition: background 0.3s;
}

.btn:hover {
    background-color: var(--accent-color);
}

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--secondary-color);
    color: var(--secondary-color);
}

.btn-outline:hover {
    background-color: var(--secondary-color);
    color: var(--white);
}

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.875rem;
}

/* Tables */
.table-responsive {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
}

th, td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: var(--light-bg);
    color: var(--primary-color);
    font-weight: 600;
}

/* Login Page specific */
.login-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 80vh;
}

.login-card {
    width: 100%;
    max-width: 400px;
}

/* Status Badges */
.badge {
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 500;
}

.badge-success { background-color: #d4edda; color: #155724; }
.badge-warning { background-color: #fff3cd; color: #856404; }
.badge-danger { background-color: #f8d7da; color: #721c24; }

/* Chat Mockup */
.chat-box {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    height: 300px;
    display: flex;
    flex-direction: column;
}

.chat-messages {
    flex: 1;
    padding: 1rem;
    overflow-y: auto;
    background: #f9f9f9;
}

.message {
    margin-bottom: 10px;
    padding: 8px 12px;
    border-radius: 15px;
    max-width: 80%;
}

.message.admin {
    background-color: var(--secondary-color);
    color: white;
    align-self: flex-end;
    margin-left: auto;
}

.message.user {
    background-color: #e9ecef;
    align-self: flex-start;
}

.chat-input {
    padding: 10px;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 10px;
}

/* Utility */
.text-center { text-align: center; }
.mt-3 { margin-top: 1rem; }
.d-flex { display: flex; }
.justify-between { justify-content: space-between; }
.align-center { align-items: center; }

/* Tree View Mockup */
.tree-node {
    margin-left: 20px;
    border-left: 1px solid var(--border-color);
    padding-left: 15px;
    margin-top: 10px;
}
.tree-toggle {
    cursor: pointer;
    font-weight: bold;
    color: var(--secondary-color);
}