:root {
    --primary-color: #4a90e2;
    --danger-color: #e74c3c;
    --bg-color: #f4f7f6;
    --card-bg: #ffffff;
    --text-color: #333333;
    --output-bg: #1e1e1e;
    --output-text: #00ff66;
}

body {
    font-family: 'Segoe UI', sans-serif;
    background-color: var(--bg-color);
    display: flex; justify-content: center; padding: 20px;
}

.app-container {
    background: var(--card-bg);
    width: 100%; max-width: 900px;
    padding: 30px; border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.app-header { 
    text-align: center;
    margin-bottom: 25px; 
    border-bottom: 1px solid #eee; 
    padding-bottom: 15px; 
}

.form-group { 
    margin-bottom: 20px; 
}

.form-group label { 
    display: block; 
    font-weight: bold; 
    margin-bottom: 8px; 
}

input[type="text"] {
    width: 100%; padding: 12px; border: 1px solid #ddd; border-radius: 6px;
    font-family: monospace; font-size: 16px;
}

.button-group { 
    display: flex; 
    gap: 10px; 
    margin-bottom: 25px; 
}

.action-btn, .clear-btn {
    flex: 1; padding: 14px; border: none; border-radius: 6px;
    font-weight: bold; cursor: pointer; transition: 0.2s;
}

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

.action-btn:hover { 
    background: #357abd; 
}

.clear-btn { 
    background: #eee; 
    color: #333; 
}

.clear-btn:hover { 
    background: #ddd; 
}

.output-box-container { 
    margin-bottom: 15px; 
}

.output-label { 
    font-size: 14px; 
    font-weight: bold; 
    margin-bottom: 5px; 
}

.output-box {
    background: var(--output-bg); color: var(--output-text);
    padding: 15px; border-radius: 6px; font-family: monospace;
    font-size: 13px; word-break: break-all; min-height: 60px;
}

.file-input-wrapper { 
    position: relative; 
    border: 2px dashed #ddd; 
    border-radius: 6px; 
    text-align: center; 
    padding: 20px; 
    cursor: pointer; 
}

.file-input-wrapper input { 
    position: absolute; 
    left: 0; 
    top: 0;
    opacity: 0; 
    width: 100%; 
    height: 100%; 
    cursor: pointer; 
}

.output-box {
    background: var(--output-bg);
    color: var(--output-text);
    padding: 15px;
    border-radius: 6px;
    font-family: 'Courier New', monospace; 
    font-size: 13px;
    line-height: 1.6;
    word-break: break-all;
    white-space: pre-wrap; 
}