There are two sealing techniques that seal the Nine Tails.
When the Kyuubi escaped from the control of the masked man, according to the Yondaime's explanation, it was theoretically impossible to seal such a huge amount of chakra. So half of the Kyuubi were sealed by the fourth-generation ghouls. After the Yondaime used the method of sealing away the corpses, his long-lost body became noticeably smaller. Only then would there be room for Kyuubi to move, and only then would there be a scene where Kyuubi's nails penetrated the two of them. What is in Naruto's body is the sealing technique spread from Naruto's mother Kushina's hometown, the Four Symbols Sealing Technique, which is sealed in Naruto's body. According to Kushina, she taught the fourth generation the sealing technique. It is conceivable that the fourth generation can repair the seal.
The first Yondaime used the corpse seal.
Half of the Nine-Tails is in the Yondaime himself
After the corpses were sealed, the Nine-Tails' size became significantly smaller. Look at such a big footprint and now the feet are so small.
The last one used is the Bagua seal, which is actually the same as the Four Symbols seal, but the translation in comics and animation is slightly different.
Play with all hands? I hope you will adopt it