* { box-sizing: border-box; }
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background: #f4f4f4;
}
.container { max-width: 960px; margin: 0 auto; }
nav {
    background: #333;
    padding: 10px;
    margin-bottom: 20px;
}
nav a {
    color: #fff;
    text-decoration: none;
    margin-right: 15px;
}
h1 { color: #2c3e50; }
table {
    border-collapse: collapse;
    width: 100%;
    background: #fff;
    margin: 10px 0;
}
th, td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: left;
}
th { background: #2c3e50; color: white; }
.flash {
    padding: 10px;
    margin: 10px 0;
    border-radius: 4px;
    background: #d4edda;
    color: #155724;
}
.btn {
    display: inline-block;
    padding: 6px 12px;
    background: #007bff;
    color: #fff;
    text-decoration: none;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 14px;
    margin: 2px;
}
.btn:hover { background: #0056b3; }
input[type=text], input[type=number], input[type=file] {
    padding: 4px;
    margin: 2px;
    border: 1px solid #ddd;
    border-radius: 4px;
}
.section {
    background: white;
    padding: 15px;
    border-radius: 6px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}