/* General Styles */
body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    color: #333;
}

.container {
    width: 80%;
    margin: 0 auto;
    background-color: #fff;
    padding: 20px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    margin-top: 20px;
}

h1 {
    text-align: center;
}

button {
    background-color: #007bff;
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin: 5px;
}

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

.user-name-section {
    margin-bottom: 20px;
}

.user-name-section input {
    width: calc(100% - 20px);
    padding: 10px;
    margin: 5px 0;
    border: 1px solid #ddd;
    border-radius: 5px;
}

#gradeTable {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

#gradeTable th, #gradeTable td {
    border: 1px solid #ddd;
    padding: 10px;
    text-align: left;
}

#gradeTable th {
    background-color: #f4f4f4;
}

#result {
    background-color: #dff0d8;
    color: #3c763d;
    padding: 15px;
    border: 1px solid #d6e9c6;
    border-radius: 5px;
    margin-top: 20px;
    text-align: center;
}

/* Error Popup */
.error-popup {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.5);
}

.error-popup-content {
    background-color: #fefefe;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 500px;
    border-radius: 10px;
}

.error-popup-close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.error-popup-close:hover,
.error-popup-close:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}

/* Developer Info */
.developer-info {
    display: inline-block;
    align-items: center;
    margin-top: 20px;
    padding: 20px;
    background-color: #fff;
    color: #007bff;
    border-radius: 8px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
}

.developer-info img {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    margin-bottom: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
}

.developer-info div {
    max-width: 200px;
}

.developer-info h3 {
    margin-bottom: 10px;
}

.myportfolio {
    margin-top: 15px;
}

.button-link {
    display: inline-block;
    background-color: #007bff;
    color: white;
    padding: 10px 15px;
    text-decoration: none;
    border-radius: 5px;
}

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

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.5);
}

.modal-content {
    background-color: #fefefe;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 600px;
    border-radius: 10px;
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}

.slide {
    display: none;
}

.slide.active {
    display: block;
}

/* Responsive Styles */
@media (max-width: 768px) {
    .container {
        width: 95%;
        padding: 10px;
    }
    
    #gradeTable input,
    #gradeTable select {
        width: 100%;
    }
    
    button {
        width: 100%;
        margin-bottom: 10px;
    }
}