JSFiddle - React, Tailwind, and code Playground

HTML

<header class="header" id="header">
    <div class="container">
      <div class="header__inner">

        <div class="logo">
            <a href=""class="logo__href">
              <img class="logo__img"src="img\logo.png" alt="">
            </a>
        </div>

        <nav class="nav">
          <a href="#" class="enter">войти</a>
          <a href="#" class="reg" data-text="Зарегистрироваться">Зарегистрироваться</a>
        </nav>

      </div>
    </div>
  </header>

CSS

/* Header
  ==========================*/
.header {
  background-color: #fff;
  padding: 21px 0;
}

.header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  padding-right: 20px;
}

.logo__img {
  height: 70px;
}

.nav {
  display: flex;
  align-items: center;

}

.enter {
  padding: 6px 18px;
  margin-right: 21px;
  margin-left: 57px;
  background: #DA1111;
  box-shadow: -2px 4px 4px #FFD0D0;
  border-radius: 10px;
  text-decoration: none;

  font-style: normal;
  font-weight: 600;
  font-size: 15px;
  text-transform: uppercase;
  color: #fff;


}

.enter:hover {
  background-color: #fff;
  border: 1px solid #DA1111;
  color: #DA1111;
  transition: 0, 2s linear;
  box-shadow: none;
}

.reg {
  position: relative;
  font-size: 15px;
  text-transform: uppercase;
  text-decoration: none;
  font-weight: bold;
  color: #DA111100;

}

.reg::after {
  content: attr(data-text);
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: #DA1111;
  font-weight: 400;
}

.reg:hover::after {
  font-weight: bold;
  box-shadow: none;
}