style.css

* {
  box-sizing: border-box;
}

h1 {
  color: #f47c7c;
}

body {
  background-image: linear-gradient(to top, #ef9f9f, #fad4d4, #fff2f2);
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 0;
  min-height: 100vh;
}

.todo-container {
  border: none;
  max-width: 100%;
  width: 400px;
}

#todo-input {
  border: none;
  display: block;
  background-color: #fad4d4;
  font-size: 2rem;
  padding: 0.5rem 2rem 0.5rem 0.5rem;
  width: 100%;
}

#todo-input:active {
  border: 2px solid #f47c7c;
}

#todo-list {
  padding: 0.5rem 2rem 0.5rem 0.5rem;
  background-color: #fff2f2;
  list-style-type: none;
  margin: 0;
  padding: 0;
}

#todo-list li {
  font-size: 1.5rem;
  user-select: none;
}

.complete {
  color: #f47c7c;
  text-decoration: line-through;
}

li button {
  width: 1.5rem;
  height: 1.5rem;
  margin: 0.5rem;
  border: 2px solid #ef9f9f;
  border-radius: 8px;
  cursor: pointer;
}

li button:active {
  border: 2px solid #ef9f9f;
}

.reset-btn-wrapper {
  margin-top: 1rem;
}

.reset-btn-wrapper button {
  color: #ef9f9f;
  font-weight: bold;
  font-size: 1rem;
  width: 120px;
  height: 30px;
  border: 3px solid #fad4d4;
  background-color: #fff2f2;
  font-display: 20px;
  padding: 0.2rem 1rem;
  cursor: pointer;
}

.reset-btn-wrapper:active {
  border: 2px solid #ef9f9f;
}