* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: #ffffff;
  color: #111827;
  transition: background-color 180ms ease, color 180ms ease;
}

body.dark-mode {
  background-color: #0b1020;
  color: #e5e7eb;
}

.container {
  width: min(90vw, 540px);
  padding: 24px;
  border-radius: 12px;
  background-color: #f3f4f6;
  text-align: center;
  transition: background-color 180ms ease;
}

body.dark-mode .container {
  background-color: #172036;
}

h1 {
  margin-top: 0;
}

#theme-toggle {
  border: 0;
  padding: 10px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  background-color: #111827;
  color: #f9fafb;
}

body.dark-mode #theme-toggle {
  background-color: #e5e7eb;
  color: #111827;
}