body {
  margin: 0;
  padding: 20px;
  background: linear-gradient(to top right, #ffe4e1, #fff0f5);
  font-family: 'Poppins', sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 100vh;
  overflow: hidden;
  position: relative;
  box-sizing: border-box;
}

.navbar {
  width: calc(100% - 40px);
  background-color: rgba(255, 255, 255, 0.7);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 40px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.05);
  position: fixed;
  top: 20px;
  left: 20px;
  right: 20px;
  border-radius: 12px;
  z-index: 100;
  box-sizing: border-box;
}

.navbar h2 {
  color: #ff4d6d;
  font-weight: bold;
  margin: 0;
}

.navbar ul {
  list-style: none;
  display: flex;
  gap: 20px;
  margin: 0;
  padding: 0;
}

.navbar ul li a {
  text-decoration: none;
  color: #333;
  font-weight: bold;
  padding: 8px 16px;
  border-radius: 10px;
  transition: all 0.3s ease;
  background-color: #ffe9ee;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.navbar ul li a:hover {
  background-color: #ffccd5;
  color: #b3003c;
  transform: translateY(-1px);
}

.letter {
  background: white;
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  max-width: 600px;
  max-height: 70vh;
  overflow-y: auto;
  margin-top: 120px;
  text-align: center;
  line-height: 1.6;
  position: relative;
  z-index: 10;
  box-sizing: border-box;
}

.letter h1 {
  font-family: 'Poppins', sans-serif;
  color: #ff4d6d;
  margin-bottom: 20px;
}

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

.letter ul li {
  margin-bottom: 10px;
}

.letter ul li a {
  display: inline-block;
  padding: 10px 20px;
  background-color: #ffe9ee;
  color: #333;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 500;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
}

.letter ul li a:hover {
  background-color: #ffccd5;
  color: #b3003c;
  transform: translateY(-1px);
}

#letterContent {
  white-space: pre-wrap;
}

.heart {
  position: absolute;
  width: 20px;
  height: 20px;
  background: red;
  transform: rotate(45deg);
  animation: float 6s ease-in-out infinite;
}

.heart::before,
.heart::after {
  content: "";
  width: 20px;
  height: 20px;
  background: red;
  border-radius: 50%;
  position: absolute;
}

.heart::before {
  top: -10px;
  left: 0;
}

.heart::after {
  left: -10px;
  top: 0;
}

@keyframes float {
  0% {
    transform: translateY(0) rotate(45deg);
    opacity: 1;
  }
  100% {
    transform: translateY(-800px) rotate(45deg);
    opacity: 0;
  }
}

.heart:nth-child(1) { left: 10%; animation-delay: 0s; }
.heart:nth-child(2) { left: 30%; animation-delay: 2s; }
.heart:nth-child(3) { left: 60%; animation-delay: 4s; }
.heart:nth-child(4) { left: 80%; animation-delay: 1s; }
.heart:nth-child(5) { left: 50%; animation-delay: 3s; }