:root {
    --bg-color: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --border-color: #dddddd;
    --accent-color: #000000;
    --success-color: #28a745;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    padding: 2rem 1rem;
}

.card {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

h1, h2, h3 {
    font-weight: 700;
    color: var(--text-primary);
}

.btn-primary {
    background-color: var(--accent-color);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

.btn-primary:hover {
    background-color: #333333;
}

.progress {
    height: 1.5rem;
    background-color: #eeeeee;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.progress-bar {
    background-color: var(--accent-color);
    height: 100%;
    transition: width 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.8rem;
    font-weight: bold;
}

.file-item {
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.file-item:last-child {
    border-bottom: none;
}

.file-name {
    font-weight: 600;
}

.file-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    text-align: center;
    color: var(--text-secondary);
    cursor: pointer;
    transition: background-color 0.2s;
}

.drop-zone:hover {
    background-color: #f9f9f9;
    border-color: var(--accent-color);
}