body {
    background-color: #f5f5f5;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    padding: 20px 0;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

.card {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    border: none;
}

.card-header {
    background: #fff;
    border-bottom: 1px solid #eee;
    padding: 20px;
}

.card-header h3 {
    margin: 0;
    color: #333;
    font-size: 24px;
    font-weight: 500;
}

.card-body {
    padding: 30px;
}

.alert-danger {
    background-color: #fff2f0;
    border: none;
    border-radius: 4px;
    padding: 20px;
}

.alert-danger h5 {
    color: #333;
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 15px;
}

.alert-danger ul {
    padding-left: 20px;
}

.alert-danger li {
    margin-bottom: 5px;
}

.text-danger {
    color: #ff4d4f !important;
}

.text-info {
    color: #1890ff !important;
}

.text-success {
    color: #52c41a !important;
}

.form-control {
    height: 40px;
    border: 1px solid #d9d9d9;
    border-radius: 4px;
    padding: 8px 12px;
    font-size: 14px;
}

.form-control:focus {
    border-color: #40a9ff;
    box-shadow: 0 0 0 2px rgba(24,144,255,0.2);
}

.form-control::placeholder {
    color: #bfbfbf;
}

.form-check-input {
    margin-top: 0.3em;
}

.form-check-label {
    font-size: 14px;
}

.btn {
    height: 40px;
    padding: 0 20px;
    font-size: 14px;
    border-radius: 4px;
    font-weight: 500;
}

.btn-secondary {
    background: #f5f5f5;
    border: 1px solid #d9d9d9;
    color: #666;
}

.btn-secondary:hover {
    background: #e8e8e8;
    border-color: #d9d9d9;
    color: #666;
}

.btn-success {
    background: #52c41a;
    border: none;
}

.btn-success:hover {
    background: #73d13d;
}

.text-primary {
    color: #1890ff !important;
}

a.text-primary:hover {
    color: #40a9ff !important;
    text-decoration: none;
}

#result {
    transition: all 0.3s ease;
}

#copyBtn {
    margin-top: 1rem;
    padding: 0.5rem 1rem;
}

input[type="password"] {
    letter-spacing: 0.1em;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .card-body {
        padding: 1.5rem;
    }
    
    .btn {
        width: 100%;
        margin: 0.5rem 0;
    }
}