/*
  Design tokens: define the small visual system once so colors and spacing can
  be changed without searching through the rest of the stylesheet.
*/
:root {
  --page-background: #ffffff;
  --card-background: #ffffff;
  --primary-text: #12263a;
  --accent: #1677ff;
  --shadow: 0 16px 40px rgb(18 38 58 / 12%);
}

/*
  Remove the browser's default body margin and center the card in the visible
  viewport. min-height lets the layout remain centered on taller screens.
*/
body {
  min-height: 100vh;
  margin: 0;
  display: grid;
  place-items: center;
  background: var(--page-background);
  color: var(--primary-text);
  font-family: Arial, Helvetica, sans-serif;
}

/* The only visual component in this starter app. */
.welcome-card {
  width: min(90%, 42rem);
  box-sizing: border-box;
  padding: 3rem;
  border-top: 0.5rem solid var(--accent);
  border-radius: 1rem;
  background: var(--card-background);
  box-shadow: var(--shadow);
  text-align: center;
}

/* Use a responsive size so the heading fits on small screens. */
h1 {
  margin: 0;
  font-size: clamp(2.25rem, 8vw, 4.5rem);
  line-height: 1.1;
}

/* Keep the name visually subordinate to the main greeting. */
p {
  margin: 1rem 0 0;
  font-size: clamp(1.125rem, 3vw, 1.5rem);
}