body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

h1 {
    text-align: center;
    color: #333;
}

.filter-section {
    margin-bottom: 20px;
    padding: 15px;
    background: #eff6ff;
    border-radius: 5px;
}

.filter-section form {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
}

.filter-section label {
    font-weight: bold;
}

.filter-section input, .filter-section select {
    padding: 5px;
    border: 1px solid #ccc;
    border-radius: 3px;
}

.filter-section button {
    padding: 5px 10px;
    background: #dbeafe;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}

.table-section {
    margin-bottom: 20px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}

th, td {
    padding: 10px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background: #f2f2f2;
    font-weight: bold;
}

tr.returned {
    background: #eaf7ea;
}

tr.overdue {
    background: #fde7e7;
}

tr.planned {
    background: #e7f0ff;
}

.buttons {
    text-align: center;
}

.buttons a {
    display: inline-block;
    padding: 10px 20px;
    background: #dbeafe;
    color: #111827;
    text-decoration: none;
    border-radius: 5px;
}

form {
    display: flex;
    flex-direction: column;
    gap: 15px;
    max-width: 500px;
    margin: 0 auto;
}

form label {
    font-weight: bold;
}

form input, form textarea, form select {
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 3px;
}

form textarea {
    height: 80px;
    resize: vertical;
}

form button {
    padding: 10px;
    background: #dbeafe;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

form a {
    text-align: center;
    text-decoration: none;
    color: #666;
}

.flash {
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    padding: 10px;
    margin-bottom: 20px;
    border-radius: 5px;
}