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

body {
    margin: 0;
    padding: 0;
    background: #f5f7fa;
    color: #333;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

h1 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 30px;
}

.converter-tabs {
    display: flex;
    margin-bottom: 20px;
    border-bottom: 1px solid #ddd;
    overflow-x: auto;
}

.tab-btn {
    padding: 10px 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 16px;
    color: #7f8c8d;
    border-bottom: 3px solid transparent;
    transition: all 0.3s;
    white-space: nowrap;
}

.tab-btn.active {
    color: #3498db;
    border-bottom: 3px solid #3498db;
    font-weight: bold;
}

.converter-panel {
    display: none;
    background: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.converter-panel.active {
    display: block;
}

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

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #2c3e50;
}

textarea, select {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    resize: vertical;
}

textarea {
    min-height: 120px;
}

.conversion-options {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 20px 0;
}

.option-btn {
    background: #e0e0e0;
    color: #333;
    border: none;
    padding: 10px 15px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s;
}

.option-btn:hover {
    background: #d0d0d0;
}

.action-buttons, .batch-actions {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.action-btn, .convert-btn {
    background: #3498db;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: background 0.3s;
}

.action-btn:hover, .convert-btn:hover {
    background: #2980b9;
}

.advanced-options, .batch-options {
    margin: 20px 0;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 4px;
}

.option-row {
    margin-bottom: 15px;
}

.option-row label {
    display: flex;
    align-items: center;
    font-weight: normal;
    margin-bottom: 0;
}

.option-row input[type="checkbox"] {
    width: auto;
    margin-right: 8px;
}

.option-row select {
    width: auto;
    display: inline-block;
    margin-left: 8px;
    padding: 8px 12px;
}

@media (max-width: 768px) {
    .converter-tabs {
        flex-direction: column;
    }
    
    .tab-btn {
        text-align: left;
        border-bottom: none;
        border-left: 3px solid transparent;
    }
    
    .tab-btn.active {
        border-bottom: none;
        border-left: 3px solid #3498db;
    }
    
    .conversion-options {
        flex-direction: column;
    }
    
    .option-btn {
        width: 100%;
    }
}