*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: #f0f2f5;
  color: #1a1a2e;
}

#app {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 20px;
}

#screen-initial {
  text-align: center;
  width: 100%;
  max-width: 720px;
}

#screen-congrats {
  text-align: center;
  width: 100%;
  max-width: 720px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.6s ease, visibility 0.6s ease;
}

#screen-congrats.visible {
  opacity: 1;
  visibility: visible;
}

.congrats-text {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.5;
  max-width: 640px;
  margin: 0 auto 2.5rem;
  color: #1a1a2e;
}

button {
  font-family: inherit;
  font-size: 1.35rem;
  font-weight: 600;
  padding: 18px 48px;
  border: none;
  border-radius: 16px;
  cursor: pointer;
  background-color: #e63946;
  color: #fff;
  box-shadow: 0 4px 15px rgba(230, 57, 70, 0.3);
  transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
  letter-spacing: 0.02em;
}

button:hover {
  background-color: #c1121f;
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(230, 57, 70, 0.4);
}

button:active {
  transform: translateY(0);
  box-shadow: 0 2px 10px rgba(230, 57, 70, 0.3);
}

@media (max-width: 480px) {
  .congrats-text {
    font-size: 1.35rem;
  }

  button {
    font-size: 1.1rem;
    padding: 16px 36px;
    border-radius: 14px;
  }
}