.sem-section {
    margin-top: 30px;
}

.sem-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

.sem-table th,
.sem-table td {
    border-bottom: 1px solid #ddd;
    padding: 8px;
    text-align: left;
}

.sem-table th {
    background-color: #f6f6f6;
    font-weight: bold;
}

.sem-table tr:nth-child(even) {
    background: #fafafa;
}

.sem-btn {
    background: #efefef;
    border: 1px solid #ccc;
    border-radius: 4px;
    padding: 4px 8px;
    font-size: 0.9em;
    cursor: pointer;
}

.sem-btn.undo {
    background-color: #ffe0e0;
}

.sem-btn.available {
    background-color: #e0ffe0;
}

.sem-btn.taken {
    background-color: #eee;
    cursor: not-allowed;
    opacity: 0.6;
}

.sem-spots {
    list-style: none;
    margin: 0;
    padding: 0;
}

.sem-spots li {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 4px;
}