body {
    font-family: sans-serif;
    background-color: #f0f2f5;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

#app {
    background-color: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    width: 90%;
    max-width: 600px;
}

h1 {
    text-align: center;
    color: #4a4a4a;
    margin-bottom: 2rem;
}

.user-selection {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 2rem;
}

.user-selection label {
    margin-right: 1rem;
}

.user-selection select {
    padding: 0.5rem;
    border-radius: 5px;
    border: 1px solid #ccc;
}

.attendance-controls {
    text-align: center;
    margin-bottom: 2rem;
}

#attend-button {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#attend-button:hover {
    background-color: #0056b3;
}

.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background-color: #333;
    color: white;
    padding: 1rem 2rem;
    border-radius: 5px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s, visibility 0.5s;
}

.toast.show {
    opacity: 1;
    visibility: visible;
}

attendance-calendar .calendar {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 10px;
}

attendance-calendar .day {
    text-align: center;
    padding: 15px;
    border: 1px solid #eee;
    border-radius: 5px;
    cursor: default; /* 날짜 클릭 비활성화 */
    transition: background-color 0.3s;
}

attendance-calendar .day.attended {
    background-color: #28a745;
    color: white;
}