body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f7f6;
    color: #333;
    line-height: 1.6;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
}
.container {
    max-width: 800px;
    width: 100%;
}
h1, h2 {
    color: #0056b3;
}
.card {
    background: #ffffff;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 25px;
    margin-bottom: 25px;
}
button {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
    margin-top: 10px;
}
button:hover {
    background-color: #0056b3;
}
button:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
}
input[type="file"], input[type="text"] {
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    border: 1px solid #ccc;
    border-radius: 4px;
}
.result-area {
    margin-top: 15px;
    padding: 15px;
    background-color: #e9f7ef;
    border-left: 5px solid #28a745;
}
.result-area a {
    display: inline-block;
    margin-top: 10px;
    font-weight: bold;
    color: #007bff;
}
.warning {
    color: #856404;
    background-color: #fff3cd;
    border-color: #ffeeba;
    padding: 10px;
    border-radius: 5px;
    margin-top: 10px;
}
#loader {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(255, 255, 255, 0.8);
    padding: 20px 40px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0,0,0,0.2);
    font-size: 18px;
    z-index: 1000;
}
.error-message {
    background-color: #f8d7da;
    color: #721c24;
    padding: 15px;
    border-radius: 5px;
    border: 1px solid #f5c6cb;
    margin-top: 20px;
    text-align: center;
}