body {
    font-family: Arial, sans-serif;
    padding: 20px;
    background: #f4f4f4;
}
form {
    margin-bottom: 20px;
}
input, select, button {
    padding: 10px;
    margin-right: 10px;
}
#message {
    margin-bottom: 15px;
    font-weight: bold;
}
.timeline-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    border-radius: 5px;
    overflow: hidden;
}
.timeline-table th, .timeline-table td {
    padding: 10px;
    border-bottom: 1px solid #ddd;
    text-align: left;
}
.timeline-table th {
    background-color: #f0f0f0;
}
th.sortable {
    cursor: pointer;
}
th.sortable:hover {
    background-color: #e0e0e0;
}
.block-header {
    background-color: #ddd;
    font-weight: bold;
    text-align: left;
    padding: 10px;
    font-size: 1.05rem;
}
.level-kindergarten {
    background-color: #ffe4e1;
}
.level-elementary {
    background-color: #e0f7fa;
}
.level-junior {
    background-color: #fff9c4;
}
.level-senior {
    background-color: #e8f5e9;
}
.time-morning {
    border-left: 5px solid #ffcc80;
}
.time-midday {
    border-left: 5px solid #90caf9;
}
.time-afternoon {
    border-left: 5px solid #a5d6a7;
}
.past-booking td {
    text-decoration: line-through;
    opacity: 0.6;
}
.announcement {
    display: inline-block;
    background-color: #d32f2f;
    color: #fff;
    padding: 6px 12px;
    margin-bottom: 15px;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 500;
}