XSLT: Need to convert name value pair content into XML - xslt-1.0

Question

I'm new to XSLT. I have a requirement to convert an XML containing name value pair into target XML.
I need to generate a target XML where each FieldName is an element name and it value is FieldValue. Please find below the output which I need.
Thanks in advance for the help.
Source XML:
<SC>
<Header>
<Record>
<FieldName>Schema</FieldName>
<FieldValue>OrderHeader</FieldValue>
</Record>
<Record>
<FieldName>Order</FieldName>
<FieldValue>1234</FieldValue>
</Record>
</Header>
<Detail>
<Record>
<FieldName>Schema</FieldName>
<FieldValue>OrderItem</FieldValue>
</Record>
<Record>
<FieldName>Item</FieldName>
<FieldValue>1</FieldValue>
</Record>
<Record>
<FieldName>Qty</FieldName>
<FieldValue>10</FieldValue>
</Record>
</Detail>
<Detail>
<Record>
<FieldName>Schema</FieldName>
<FieldValue>OrderItem</FieldValue>
</Record>
<Record>
<FieldName>Item</FieldName>
<FieldValue>2</FieldValue>
</Record>
<Record>
<FieldName>Qty</FieldName>
<FieldValue>20</FieldValue>
</Record>
</Detail>
</SC>
Target XML to be generated:
<SC>
<OrderHeader>
<Order>1234</Order>
</OrderHeader>
<OrderItem>
<Item>1</Item>
<Qty>10</Qty>
</OrderItem>
<OrderItem>
<Item>2</Item>
<Qty>20</Qty>
</OrderItem>
</SC>
XSLT which I tried: I'm not getting the desired output
<xsl:template match="Header">
<xsl:apply-templates select="Record"/>
</xsl:template>
<xsl:template match="Record">
<xsl:if test="FieldName = 'Structure'">
<xsl:element name="{FieldValue}">
<xsl:value-of select="./text()"/>
</xsl:element>
</xsl:if>
<xsl:element name="{FieldName}">
<xsl:value-of select="FieldValue"/>
</xsl:element>
</xsl:template>

Answer 1

Here's another option that is similar to Martin's.
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="Header|Detail">
<xsl:element name="{Record[1]/FieldValue}">
<xsl:apply-templates select="Record[position()>1]"/>
</xsl:element>
</xsl:template>
<xsl:template match="Record">
<xsl:element name="{FieldName}">
<xsl:value-of select="FieldValue"/>
</xsl:element>
</xsl:template>
</xsl:stylesheet>

Answer 2

It seems you want to process the first Record child as a container element and the following siblings are to be transformed as in your description:
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="xs"
version="2.0">
<xsl:output indent="yes"/>
<xsl:template match="SC">
<xsl:copy>
<xsl:apply-templates select="*/Record[1]"/>
</xsl:copy>
</xsl:template>
<xsl:template match="SC/*/Record[1]">
<xsl:element name="{FieldValue}">
<xsl:apply-templates select="following-sibling::Record"/>
</xsl:element>
</xsl:template>
<xsl:template match="SC/*/Record[position() gt 1]">
<xsl:element name="{FieldName}">
<xsl:value-of select="FieldValue"/>
</xsl:element>
</xsl:template>
</xsl:stylesheet>