Lace Cardigan with Heart Pattern

How to knit the lace cardigan with heart pattern:
Size: Medium (US 8–10 / UK 10–12).
Materials:
300 g yarn (90% acrylic, 10% metallic, 400 m/100 g; approx. 437 yd/3.5 oz), knitting needles size 6 (US) / 4 mm (UK), crochet hook size C-2 (US) / 3 mm (UK), 6 buttons.

Lace heart pattern:
Work according to the chart, which shows only right-side rows.
On wrong-side rows, purl all stitches and yarn overs.
Work rows 1 through 48 once, then repeat rows 29 through 48 throughout.

Back:
Cast on 75 stitches and work in the lace heart pattern.
At a height of 38 cm (15 in) from the cast-on edge, for armholes bind off 5 stitches on both sides, then in every second row bind off 2 stitches once and 1 stitch once.
Then work straight.
At a height of 58 cm (23 in) from the cast-on edge, bind off all stitches.

Right front:
Cast on 39 stitches and work in the lace heart pattern.
At a height of 38 cm (15 in) from the cast-on edge, for the armhole on the left side bind off 5 stitches, then in every second row bind off 2 stitches once and 1 stitch once.
Then work straight.
At a height of 48 cm (19 in) from the cast-on edge, for the neckline on the right side bind off 10 stitches, then in every second row bind off 3 stitches three times, 2 stitches once, and 1 stitch once.
At a height of 58 cm (23 in) from the cast-on edge, bind off all stitches.

Left front: Work in the same way, but in mirror image.

Sleeves:
Cast on 39 stitches and work in the lace heart pattern.
For sleeve shaping, increase 1 stitch on both sides in every 6th row.
At a height of 40 cm (16 in) from the cast-on edge, for the sleeve cap bind off 5 stitches on both sides, then in every second row bind off 2 stitches three times, 1 stitch twelve times, and 2 stitches four times.
At a height of 56 cm (22 in) from the cast-on edge, bind off all stitches.
Work the second sleeve in the same way.

Finishing:
Sew shoulder seams.
Sew side seams and sleeve seams. Set in the sleeves.
Along the lower edge of the cardigan and the lower edges of the sleeves, work 4 rows of single crochet and 1 row of crab stitch (single crochet worked from left to right).
Work 5 rows of single crochet along the front edges and neckline.
At the same time, while working the button band on the right front, make buttonholes using chain stitches.
Then work a decorative crochet edging (alternately 1 single crochet and 5 double crochet into one base stitch).
Sew buttons onto the left front.