body {
    background: #f5f6f8;
    font-family: Arial, sans-serif;
    margin: 0;
    color: #1f2937;
}

.header {
    background: #1f2937;
    color: white;
    padding: 16px 24px;
}

.header h1 {
    margin: 0;
    font-size: 22px;
}

.layout {
    display: flex;
    min-height: calc(100vh - 58px);
}

.sidebar {
    width: 220px;
    background: #111827;
    padding: 20px 0;
}

.sidebar a {
    display: block;
    color: #e5e7eb;
    text-decoration: none;
    padding: 12px 24px;
}

.sidebar a:hover {
    background: #374151;
}

.main-content {
    flex: 1;
    padding: 24px;
}

.container {
    padding: 24px;
}

.card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.card h2 {
    margin-top: 0;
}

.btn {
    display: inline-block;
    background: #1f2937;
    color: white;
    padding: 8px 14px;
    border-radius: 6px;
    text-decoration: none;
    border: none;
    cursor: pointer;
}

.btn.secondary {
    background: #6b7280;
}

table {
    border-collapse: collapse;
    width: 100%;
    background: white;
}

th {
    background: #f3f4f6;
    text-align: left;
}

th, td {
    padding: 10px;
    border-bottom: 1px solid #e5e7eb;
}

input {
    padding: 8px;
    border: 1px solid #d1d5db;
    border-radius: 6px;
}