body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f6;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 500px;
    text-align: center;
}

header h1 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

header p {
    color: #7f8c8d;
    font-size: 0.9rem;
}

.upload-section {
    margin: 2rem 0;
}

.custom-file-upload {
    border: 1px solid #3498db;
    display: inline-block;
    padding: 6px 12px;
    cursor: pointer;
    background: #3498db;
    color: white;
    border-radius: 5px;
}

input[type="file"] {
    display: none;
}

.chat-section textarea {
    width: 100%;
    height: 100px;
    border-radius: 8px;
    border: 1px solid #ddd;
    padding: 10px;
    box-sizing: border-box;
    margin-bottom: 1rem;
    font-size: 1rem;
}

#ask-button {
    background-color: #2ecc71;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    width: 100%;
}

.response-area {
    margin-top: 2rem;
    text-align: left;
    background: #f9f9f9;
    padding: 1rem;
    border-radius: 8px;
    border-left: 4px solid #2ecc71;
}