style.css

@import url('https://fonts.googleapis.com/css?family=Roboto:400,700,900&display=swap&subset=latin-ext');

* {
  box-sizing: border-box;
}

html {
  font-family: 'Roboto', sans-serif;
  font-size: 15px;
}

body {
  background-color: #f0efe9;
}

.todo {
  background-color: white;
  color: #777;
  max-width: 20rem;
  margin: 4rem auto;
  padding-bottom: 1rem;
  border-radius: 5px;
  box-shadow: 0 0 5px lightgray;
}

.todo__header {
  padding: 2rem;
}

.date {
  display: flex;
  align-items: center;
}

.date__daynum {
  flex: 0;
  font-size: 2.5rem;
  font-weight: 900;
}

.date__monthyear {
  flex: 1;
  margin-left: 0.25rem;
}

.date__month {
  font-weight: bold;
  line-height: 1.1rem;
}

.date__year {
  line-height: 1.1rem;
}

.date__dayname {
  flex: 0;
}

.todo__new {
  display: flex;
  align-items: center;
  padding: 0 2rem;
}

.btn-add {
  width: 3rem;
  height: 3rem;
  background-color: #50e3a4;
  border: none;
  outline: none;
  border-radius: 1.5rem;

  font-size: 1.25rem;
  margin-left: -3.5rem;
}

.new-task {
  flex: 1;
  height: 2rem;
  border: 1px solid lightgray;
  border-radius: 1rem;
  line-height: 2rem;
  margin-left: 0.5rem;
  padding: 0 0.75rem;
  outline: none;
}

.task {
  padding: 1rem 2rem;
}