body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f0f0f0;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    color: #1db954;
    margin-bottom: 20px;
}

.user-info {
    margin-bottom: 20px;
    padding: 10px;
    background-color: #f8f9fa;
    border-radius: 4px;
}

.checkin-form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.course-select {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

.checkin-btn {
    padding: 12px;
    background-color: #1db954;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-top: 10px;
}

.checkin-btn:hover {
    background-color: #18a348;
}

.message {
    margin-top: 20px;
    padding: 10px;
    border-radius: 4px;
    text-align: center;
}

.message.success {
    background-color: #d4edda;
    color: #155724;
}

.message.error {
    background-color: #f8d7da;
    color: #721c24;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: #333;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    box-sizing: border-box;
}

.form-group input:focus {
    outline: none;
    border-color: #1db954;
    box-shadow: 0 0 0 2px rgba(29, 185, 84, 0.1);
}

.form-group input::placeholder {
    color: #999;
}

.send-message-btn {
    margin-top: 20px;
    padding: 12px;
    background-color: #c85460;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s;
    width: 100%;
}

.send-message-btn:hover {
    background-color: #cc3241;
}

/* highlight 凸顯按鈕的樣式, 動畫 */
.highlight {
    background-color: #cc3241;
    animation: highlight 1s ease-in-out infinite;
}

@keyframes highlight {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.hidden {
    display: none;
}

.loading-text {
    color: white;
}

.checkin-btn:disabled {
    background-color: #999;
    cursor: not-allowed;
}

.copy-message {
    background-color: #cc3241;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    border-radius: 4px;
}

.copy-area {
    width: 90%;
    min-height: 150px;
    padding: 10px;
    margin: 10px 0;
    resize: vertical; /* 可選：允許用戶調整高度 */
    border-radius: 4px;
}

.copy-btn {
    background-color: #ffffff;
    color: rgb(0, 0, 0);
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    padding: 10px;
    margin-bottom: 30px;
}

.copy-btn:hover {
    background-color: #ebf6ff;
}

.required {
    color: red;
}