style.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  font-size: 62.5%;
}

body {
  font-size: 1.6rem;
  background-color: #09090A;
}

header {
  display: flex;
  /* margin: 10rem 0 4.8rem; */
  padding: 9.9rem 12rem 4.8rem;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  position: fixed;
  background-color: #09090A;
}

button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.2rem;

  padding: 1.6rem 2.4rem;
  border: 1px solid #8B5CF6;
  border-radius: .8rem;
  background: transparent;

  font-family: 'Inter', sans-serif;
  font-weight: 600;
  font-size: 1.6rem;
  color: white;

  transition: all 300ms;
  cursor: pointer;
}

button:hover {
  background-color: #8B5CF6;
}

button:hover svg path {
  stroke: white;
}

form {
  display: flex;
  gap: 3.2rem;
  /* margin: 0 12rem; */
  padding: 23.5rem 9rem 4.8rem;
  width: fit-content;
}

.habits {
  display: flex;
  flex-direction: column;
  
  gap: 2.4rem;
  margin-top: 6.5rem;
}

.habit {
  width: 6.4rem;
  height: 6.4rem;
  font-size: 3.2rem;
  line-height: 6.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.days {
  display: flex;
  gap: 4.8rem;
}

.day {
  display: flex;
  flex-direction: column;
  gap: 2.4rem;

  font-family: 'Roboto Mono', sans-serif;
  font-weight: 700;
  font-size: 2rem;
  line-height: 125%;
  color: #A1A1AA;
}

.day div {
  padding: .8rem 0;
  text-align: center;
}

input {
  appearance: none;
  -webkit-appearance: none;

  width: 64px;
  height: 64px;

  border: 2px solid #27272A;
  border-radius: 8px;
  background: #18181B;

  cursor: pointer;
}

input:checked {
  background: #8B5CF6;
  border: 2px solid #A78BFA;
}

@media (max-width: 650px) {
  button div{
    display: none;
  }
}