body {
    font-family: 'Segoe UI', Tahoma, sans-serif;
    background: #f4f6f9;
    margin: 0;
    padding: 20px;
    color: #333;
}
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #2c3e50;
    color: white;
    padding: 15px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
}
.controls button {
    padding: 10px 20px;
    margin: 5px;
    font-size: 16px;
    cursor: pointer;
    border: none;
    border-radius: 6px;
}
.controls button:hover { background: #3498db; color: white; }

#content {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
}
th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}
tr.problem { background: #ffdddd !important; }
.login-container {
    max-width: 400px;
    margin: 100px auto;
    padding: 30px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}
.error { color: red; }