export declare function base64ToBytes(b64: string): Uint8Array;
export declare function bytesToBase64(bytes: Uint8Array): string;
/** Decodes quoted-printable encoded text (RFC 2045 §6.7) into bytes. */
export declare function decodeQuotedPrintable(input: string): Uint8Array;
/** Decodes bytes according to a charset. Falls back to latin-1 for unknown charsets. */
export declare function decodeBytes(bytes: Uint8Array, charset?: string): string;
/**
 * Decodes RFC 2047 encoded words (=?charset?B?..?= / =?charset?Q?..?=) in a
 * string, dropping whitespace between adjacent encoded words.
 */
export declare function decodeMimeEncodedWords(input: string): string;