.stl-form {
    background: #ffffff;
    border: 1px solid #e0e0e0;
    padding: 24px;
    max-width: 600px;
    margin: 40px auto;
    border-radius: 12px;
font-family: 'Open Sans', Arial, Helvetica, sans-serif;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

.stl-form label {
    font-weight: 600;
    margin-top: 14px;
    display: block;
    color: #333;
    font-size: 16px;
}

.stl-form input[type="file"],
.stl-form select,
.stl-form input[type="number"],
.stl-form input[type="submit"] {
    width: 100%;
    padding: 12px;
    margin: 10px 0 18px;
    border-radius: 6px;
    border: 1px solid #ccc;
    box-sizing: border-box;
    font-size: 16px;
    transition: border 0.2s, box-shadow 0.2s;
}

.stl-form input[type="file"]:focus,
.stl-form select:focus,
.stl-form input[type="number"]:focus {
    outline: none;
    border-color: #0073aa;
    box-shadow: 0 0 0 3px rgba(0, 115, 170, 0.2);
}

.stl-form input[type="submit"] {
    background-color: #0073aa;
    color: white;
    border: none;
    cursor: pointer;
    font-weight: 600;
    font-size: 16px;
    transition: background-color 0.2s;
}

.stl-form input[type="submit"]:hover {
    background-color: #005a87;
}

.stl-result,
.stl-error {
    padding: 20px;
    margin: 30px auto;
    max-width: 600px;
    border-radius: 10px;
    font-size: 16px;
    line-height: 1.6;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
}

.stl-result {
    background: #f1fdf7;
    border: 1px solid #b2dfdb;
    color: #2e7d32;
}

.stl-error {
    background: #fdecea;
    border: 1px solid #f5c6cb;
    color: #c62828;
}

.stl-drop-area {
    border: 2px dashed #aaa;
    border-radius: 8px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    color: #666;
    background: #f9f9f9;
    transition: border-color 0.3s, background 0.3s;
    font-size: 16px;
}

.stl-drop-area.highlight {
    border-color: #0073aa;
    background: #e6f4ff;
}

.stl-drop-area p {
    margin: 0;
    font-size: 16px;
    color: #444;
}

.stl-submit {
    background-color: #0073aa;
    color: white;
    border: none;
    cursor: pointer;
    padding: 12px;
    border-radius: 6px;
    width: 100%;
    margin-top: 16px;
    font-weight: 600;
    font-size: 16px;
    transition: background-color 0.3s;
}

.stl-submit:hover {
    background-color: #005a87;
}