:root {
    --primary-color: #4a6bff;
    --primary-hover: #3a5bef;
    --text-color: #333;
    --light-gray: #f5f5f5;
    --border-color: #ddd;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: white;
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

header p {
    font-size: 1.1rem;
    color: #666;
}

.tool-container {
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--shadow);
    overflow: hidden;
    margin-bottom: 30px;
}

.upload-section {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.file-upload {
    display: flex;
    flex-direction: column;
    align-items: center;
}

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

.upload-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.3s;
    font-weight: 500;
}

.upload-btn:hover {
    background-color: var(--primary-hover);
}

.upload-btn svg {
    margin-right: 8px;
}

.file-info {
    margin-top: 15px;
    font-size: 0.9rem;
    color: #666;
}

.pdf-viewer-container {
    padding: 20px;
    min-height: 500px;
    display: flex;
    justify-content: center;
    align-items: center;
}

#pdf-viewer {
    width: 100%;
    height: 100%;
    overflow: auto;
    border: 1px dashed var(--border-color);
    border-radius: 6px;
}

.placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: #999;
    padding: 40px;
    text-align: center;
}

.placeholder svg {
    margin-bottom: 20px;
}

.placeholder p {
    font-size: 1.1rem;
}

.toolbar {
    display: flex;
    justify-content: center;
    padding: 15px;
    border-top: 1px solid var(--border-color);
    gap: 10px;
}

.tool-btn {
    display: flex;
    align-items: center;
    padding: 10px 15px;
    background-color: white;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.9rem;
}

.tool-btn:hover {
    background-color: var(--light-gray);
}

.tool-btn svg {
    margin-right: 8px;
}

.tool-btn.primary {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.tool-btn.primary:hover {
    background-color: var(--primary-hover);
}

.tool-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

footer {
    text-align: center;
    padding: 20px;
    color: #666;
    font-size: 0.9rem;
}

/* PDF.js viewer customization */
.pdf-page {
    margin: 10px auto;
    box-shadow: 0 0 8px rgba(0, 0, 0, 0.1);
}

@media (max-width: 768px) {
    .toolbar {
        flex-direction: column;
    }
    
    .tool-btn {
        width: 100%;
        justify-content: center;
    }
    
    header h1 {
        font-size: 2rem;
    }
}