body {
  height: 100%;
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background-color: #fff;
  color: #333;
  font-size: 20px;
}

.main-content {
  min-height: 100%;
  position: relative;
  padding-bottom: 60px;
}

header {
  background-color: #ff0000;
  color: #fff;
  text-align: center;
  padding: 20px 0;
}

header h1 {
  margin: 0;
}

header p {
  font-size: 1.2em;
}

main {
  padding: 20px;
}

.introduction,
.features,
.download {
  margin-bottom: 20px;
}

h2 {
  color: #ff0000;
}

.features ul {
  list-style: none;
  padding: 0;
}

.features li::before {
  content: "✓";
  color: #ff0000;
  margin-right: 8px;
}

footer {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 60px;
  background-color: #f2f2f2;
  text-align: center;
  padding: 20px 0;
}

.iphone-display {
  text-align: center;
  padding: 20px 0;
}

.iphone-image {
  width: 375px; /* Width of a typical iPhone */
  height: 812px; /* Height of a typical iPhone */
  max-width: 100%;
  height: auto;
}

.interactive-iphone-display {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 20px;
  padding: 10px;
}

.interactive-iphone-container {
  text-align: center;
}

.counter-controls {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

#increase-btn {
  padding: 10px 20px;
  font-size: 1em;
  cursor: pointer;
}

.current-number {
  display: flex;
  flex-direction: column;
  align-items: center;
}

#current-number-field {
  margin-top: 5px;
  padding: 5px;
  text-align: center;
}