* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: #f0f2f5;
    color: #1a1a1a;
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 40px auto;
    padding: 30px;
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    color: #1a1a1a;
    margin-bottom: 30px;
    font-size: 2.2em;
    font-weight: 600;
}

.input-section {
    background: #f8fafc;
    padding: 25px;
    border-radius: 12px;
    margin-bottom: 25px;
}

.input-group {
    margin: 20px 0;
}

.input-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 500;
    color: #4a5568;
    font-size: 1.1em;
}

.file-upload {
    position: relative;
    border: 2px dashed #cbd5e0;
    border-radius: 12px;
    padding: 30px;
    text-align: center;
    background: white;
    transition: all 0.3s ease;
}

.file-upload:hover {
    border-color: #4299e1;
    background: #f0f7ff;
}

.file-upload input[type="file"] {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    opacity: 0;
    cursor: pointer;
}

.file-upload-text {
    color: #718096;
    font-size: 1.1em;
}

input[type="text"] {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease;
}

input[type="text"]:focus {
    outline: none;
    border-color: #4299e1;
    box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.2);
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    text-decoration: none;
}

.process-btn {
    background: #4299e1;
    color: white;
    width: 100%;
}

.process-btn:hover {
    background: #3182ce;
    transform: translateY(-1px);
}

.download-btn {
    display: none;
    background: #48bb78;
    color: white;
    margin: 20px auto;
    width: 200px;
}

.download-btn:hover {
    background: #38a169;
    transform: translateY(-1px);
}

.preview-section {
    text-align: center;
    margin-top: 30px;
}

#preview {
    max-width: 100%;
    margin: 20px 0;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    display: none;
}

.file-upload-text {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    pointer-events: none;
}

.file-upload.dragover {
    border-color: #4299e1;
    background: #f0f7ff;
}

.upload-icon {
    font-size: 48px;
    margin-bottom: 15px;
    color: #718096;
}