body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f4f4f4;
}
.header {
    text-align: center;
    margin-bottom: 20px;
}
.form-container {
    max-width: 400px;
    margin: auto;
    padding: 20px;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    transition: opacity 0.5s ease-in-out;
}
.form-container.hidden {
    opacity: 0;
    pointer-events: none;
}
.form-container label {
    font-weight: bold;
    margin-bottom: 10px;
    display: block;
}
.form-container input[type="number"] {
    width: calc(100% - 22px);
    padding: 10px;
    margin-bottom: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
}
.form-container .login-btn {
    width: 100%;
    padding: 10px;
    background-color: #28a745;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    margin-bottom: 20px;
}
.form-container .login-btn:hover {
    background-color: #218838;
}
.welcome-panel {
    max-width: 400px;
    margin: auto;
    margin-top: 20px;
    padding: 20px;
    border: 2px solid #ddd;
    background-color: #f9f9f9;
    text-align: center;
    display: none;
    transition: opacity 0.5s ease-in-out;
}
.check-in-button {
    display: block;
    margin: 20px auto;
    padding: 20px 40px;
    font-size: 18px;
    cursor: pointer;
    background-color: #28a745;
    color: #fff;
    border: none;
    border-radius: 5px;
}
.check-in-button:hover {
    background-color: #218838;
}
.check-in-button::before {
    content: "\2713 "; /* Check mark icon */
    margin-right: 5px;
}
.center-text {
    text-align: center;
    margin-top: 10px;
    margin-bottom: 20px;
}
.error-message {
    color: red;
    text-align: center;
    margin: 20px;
    display: none;
    transition: opacity 0.5s ease-in-out;
}
.message.visible {
    display: block;
    opacity: 1;
}

/* Success message styles */
.success-message {
    display: flex;
    align-items: center;
    max-width: 400px;
    margin: auto;
    margin-top: 20px;
    padding: 10px 20px;
    background-color: #d4edda;
    border: 1px solid #c3e6cb;
    border-radius: 5px;
    color: #155724;
    font-size: 16px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity 0.5s ease-in-out, transform 0.5s ease-in-out;
}
.success-message.visible {
    opacity: 1;
    transform: translateY(0);
}
.success-message .checkmark {
    display: inline-block;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background-color: #155724;
    color: #fff;
    margin-right: 10px;
    position: relative;
}
.success-message .checkmark::before {
    content: "\2713";
    display: inline-block;
    width: 24px;
    height: 24px;
    text-align: center;
    line-height: 24px;
    font-size: 18px;
    animation: checkmark-animation 0.5s ease-in-out;
}
@keyframes checkmark-animation {
    0% {
        opacity: 0;
        transform: scale(0);
    }
    50% {
        opacity: 1;
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
    }
}