/* 英文字母大小写转换工具样式 */
.letter-converter-container {
    max-width: 1200px;
    margin: 0 auto;
}

.letter-converter-container .py-card {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 2px 12px rgba(0,0,0,.08);
    padding: 22px;
    margin-bottom: 10px;
}

.letter-converter-container .py-card .header {
    padding-bottom: 0 !important;
}

.letter-converter-container .py-card .header h2 {
    font-size: 17px;
    color: #333;
    border-left: 4px solid #17a2b8;
    padding-left: 10px;
    margin: 0;
    font-weight: 600;
}

.letter-converter-container .input-group {
    margin-bottom: 15px;
}

.letter-converter-container .input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #333;
    font-size: 14px;
}

.letter-converter-container textarea {
    width: 100%;
    min-height: 200px;
    padding: 12px;
    border: 1px solid #ced4da;
    border-radius: 6px;
    font-size: 14px;
    line-height: 1.5;
    resize: vertical;
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    background-color: #f8f9fa;
    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.letter-converter-container textarea:focus {
    border-color: #17a2b8;
    box-shadow: 0 0 0 0.2rem rgba(23, 162, 184, 0.25);
    outline: none;
    background-color: #fff;
}

.letter-converter-container .btn-group {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin: 20px 0;
}

.letter-converter-container .btn {
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid transparent;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    white-space: nowrap;
}

.letter-converter-container .btn i {
    font-size: 14px;
}

.letter-converter-container .btn-primary {
    background-color: #17a2b8;
    color: white;
    border-color: #17a2b8;
}

.letter-converter-container .btn-primary:hover {
    background-color: #138496;
    border-color: #117a8b;
}

.letter-converter-container .btn-success {
    background-color: #28a745;
    color: white;
    border-color: #28a745;
}

.letter-converter-container .btn-success:hover {
    background-color: #218838;
    border-color: #1e7e34;
}

.letter-converter-container .btn-warning {
    background-color: #ffc107;
    color: #212529;
    border-color: #ffc107;
}

.letter-converter-container .btn-warning:hover {
    background-color: #e0a800;
    border-color: #d39e00;
}

.letter-converter-container .btn-info {
    background-color: #17a2b8;
    color: white;
    border-color: #17a2b8;
}

.letter-converter-container .btn-info:hover {
    background-color: #138496;
    border-color: #117a8b;
}

.letter-converter-container .btn-secondary {
    background-color: #6c757d;
    color: white;
    border-color: #6c757d;
}

.letter-converter-container .btn-secondary:hover {
    background-color: #5a6268;
    border-color: #545b62;
}

.letter-converter-container .btn-danger {
    background-color: #dc3545;
    color: white;
    border-color: #dc3545;
}

.letter-converter-container .btn-danger:hover {
    background-color: #c82333;
    border-color: #bd2130;
}

.letter-converter-container .btn-outline-secondary {
    background-color: transparent;
    color: #6c757d;
    border-color: #6c757d;
}

.letter-converter-container .btn-outline-secondary:hover {
    background-color: #6c757d;
    color: white;
}

.letter-converter-container .result-container {
    margin-top: 20px;
}

.letter-converter-container .result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.letter-converter-container .result-header h3 {
    margin: 0;
    font-size: 16px;
    color: #333;
    font-weight: 600;
}

.letter-converter-container .char-count {
    font-size: 12px;
    color: #6c757d;
    background: #f8f9fa;
    padding: 4px 8px;
    border-radius: 4px;
}

.letter-converter-container .output-textarea {
    background-color: #f8f9fa;
    border-color: #e9ecef;
    color: #495057;
}

.letter-converter-container .help-section {
    margin-top: 30px;
}

.letter-converter-container .help-section h3 {
    font-size: 16px;
    color: #333;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 1px solid #e9ecef;
    font-weight: 600;
}

.letter-converter-container .help-section ul {
    padding-left: 20px;
    margin: 0;
}

.letter-converter-container .help-section li {
    margin-bottom: 8px;
    color: #555;
    line-height: 1.5;
}

.letter-converter-container .help-section li:last-child {
    margin-bottom: 0;
}

.letter-converter-container .faq-section {
    margin-top: 30px;
}

.letter-converter-container .faq-item {
    margin-bottom: 15px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
    border-left: 3px solid #17a2b8;
}

.letter-converter-container .faq-item h4 {
    margin: 0 0 8px 0;
    font-size: 14px;
    color: #333;
    font-weight: 600;
}

.letter-converter-container .faq-item p {
    margin: 0;
    color: #555;
    font-size: 13px;
    line-height: 1.5;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .letter-converter-container {
        padding: 0 15px;
    }
    
    .letter-converter-container .py-card {
        padding: 15px;
    }
    
    .letter-converter-container textarea {
        min-height: 150px;
    }
    
    .letter-converter-container .btn-group {
        flex-direction: column;
    }
    
    .letter-converter-container .btn {
        width: 100%;
        justify-content: center;
    }
}