styles.css

* {
  box-sizing: border-box;
}

body {
  --main_color: #1c3fbbff;
  --accent_color: #83a4fd;
  --button_text_color: var(--main_color);
  --button-bg-color: var(--accent_color);
  --link-text-color: var(--accent_color);
  --transition: 0.3s;

  padding: 0;
  margin: 0;
  background-color: var(--main_color);
  color: var(--accent_color);
  font-family: "Press Start 2P", cursive;
  transition: var(--transition);
}

body.dark {
  --main_color: #000000;
  --accent_color: #7af9c3;
  --button_text_color: var(--main_color);
  --button-bg-color: var(--accent_color);
  --link-text-color: var(--accent_color);

  background-color: var(--main_color);
  color: var(--accent_color);
}

.page-wrapper {
  max-width: 960px;
  width: 90%;
  margin: 0 auto;
}

.header {
  padding: 1.5rem 0;
}

.options-wrapper {
  display: flex;
  flex-direction: column-reverse;
  align-items: start;
}

.current-date {
  font-size: clamp(0.75rem, 2.5vw, 1rem);
}

.mode-btn {
  font-size: clamp(0.5rem, 2.5vw, 0.75rem);
}

.greeting {
  font-size: clamp(1.1rem, 3vw, 2rem);
}

.main {
  text-align: center;
  padding: 6rem 0;
}

.btns-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.counter {
  font-size: clamp(6rem, 15vw, 10rem);
  margin-bottom: 5rem;
}

.btn {
  font-family: "Press Start 2P", cursive;
  background-color: var(--button-bg-color);
  color: var(--button_text_color);
  border: none;
  padding: 1em;
  cursor: pointer;
}

.author {
  font-size: clamp(0.5rem, 0.75vw, 0.75rem);
  color: var(--link-text-color);
}

@media (min-width: 800px) {
  .options-wrapper {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .main {
    padding: 9rem;
  }
  .btns-wrapper {
    flex-direction: row;
    justify-content: space-evenly;
  }
}