style.css

:root {
  --line-height: 30px;
  --page-color: #f5f5f4;
  --line-color: #607d8b;
}

* {
  box-sizing: border-box;
}

body {
  background: #fb923c;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  font-family: "Indie Flower", cursive;
  font-weight: bold;
  color: #272727;
}

.container {
  width: 80vw;
  max-width: 500px;
}

.heading {
  background: var(--page-color);
  text-align: center;
  box-shadow: 4px 4px 4px #403f3e;
  border-top-left-radius: 10px;
  border-top-right-radius: 10px;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  border-bottom: 5px double var(--line-color);
}

.top-left-empty {
  grid-column: 1 / 3;
}

.top-left-empty,
.margin {
  border-right: 5px double var(--line-color);
}

.heading-text {
  margin: 0.4em 0;
  grid-column: 3 / 13;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  font-size: 30px;
  letter-spacing: -1px;
}

.page {
  border-top-left-radius: 0;
  border-top-right-radius: 0;
  border-bottom-left-radius: 10px;
  border-bottom-right-radius: 10px;
  box-shadow: 4px 4px 4px #403f3e;
  min-height: calc(var(--line-height) * 10);
  font-size: 20px;
  background: repeating-linear-gradient(
    var(--page-color) 0 calc(var(--line-height) - 2px),
    var(--line-color) calc(var(--line-height) - 2px) var(--line-height)
  );
  line-height: var(--line-height);
  display: grid;
  grid-template-columns: repeat(12, 1fr);
}

.margin {
  grid-column: 1 / 3;
  text-align: center;
}

.text-area {
  grid-column: 3 / 13;
  padding: 0 10px;
}

.button-wrapper {
  display: flex;
  justify-content: center;
}

#btn {
  background: #ff4742;
  border: 1px solid #ff4742;
  border-radius: 6px;
  box-shadow: rgba(0, 0, 0, 0.1) 1px 2px 4px;
  box-sizing: border-box;
  color: #ffffff;
  cursor: pointer;
  font-size: 16px;
  font-weight: 800;
  line-height: 16px;
  margin-top: 16px;
  outline: 0;
  padding: 12px 14px;
  text-align: center;
  user-select: none;
}

#btn:hover {
  background-color: initial;
  background-position: 0 0;
  color: white;
  background-color: #272727;
}