body {
    font-family: Arial, sans-serif;
    margin: 0;
    background: #f4f6f8;
    color: #1f2937;
}
header {
    background: #0f172a;
    color: white;
    padding: 16px 24px;
}
nav a {
    color: white;
    margin-right: 14px;
    text-decoration: none;
}
main {
    max-width: 1100px;
    margin: 24px auto;
    padding: 0 16px;
}
.card {
    background: white;
    border-radius: 10px;
    padding: 18px;
    margin-bottom: 16px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
}
.table {
    width: 100%;
    border-collapse: collapse;
}
.table th, .table td {
    border-bottom: 1px solid #e5e7eb;
    padding: 10px;
    text-align: left;
}
.btn {
    display: inline-block;
    background: #2563eb;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 10px 14px;
    text-decoration: none;
    cursor: pointer;
}
.btn-secondary { background: #475569; }
.btn-danger { background: #dc2626; }
.btn-success { background: #059669; }
form label {
    display: block;
    margin-top: 10px;
    margin-bottom: 4px;
    font-weight: bold;
}
form input, form select {
    width: 100%;
    padding: 10px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    box-sizing: border-box;
}
.alert {
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 12px;
}
.alert-success { background: #dcfce7; }
.alert-danger { background: #fee2e2; }
.alert-warning { background: #fef3c7; }
.alert-info { background: #dbeafe; }
.small { font-size: 0.92rem; color: #475569; }