body {
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #ffb6c1, #ff69b4, #ff1493);
    font-family: 'Poppins', sans-serif;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    overflow: hidden;
}

h1 {
    color: white;
    font-size: 2em;
    margin-bottom: 30px;
    text-shadow: 0 0 10px rgba(255,255,255,0.8);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.envelope {
    position: relative;
    width: 300px;
    height: 150px;
    background: #ff4d6d;
    border-radius: 10px;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(0,0,0,0.3);
    transition: transform 0.4s ease;
}

.envelope:hover {
    transform: scale(1.05);
}

.flap {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #ff758f;
    clip-path: polygon(0 0, 50% 50%, 100% 0);
    transform-origin: top;
    transition: transform 1s ease;
    z-index: 2;
}

.letter {
    position: absolute;
    top: 100%;
    left: 5%;
    width: 100%;
    height: 310px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    text-align: center;
    padding: 15px 20px;
    transform: translateY(0);
    transition: transform 1s ease;
    opacity: 0;
    box-sizing: border-box;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.message {
    font-size: 1em;
    color: #ff1493;
    opacity: 0;
    transition: opacity 1s ease;
    line-height: 1.5em;
    margin: 0;
    padding: 0 5px;
}

.open .flap {
    transform: rotateX(180deg);
}

.open .letter {
    transform: translateY(-160px);
    opacity: 1;
}

.show-message .message {
    opacity: 1;
}

/* Corações flutuando */
.heart {
    position: absolute;
    color: #fff;
    font-size: 24px;
    animation: float 6s linear infinite;
    opacity: 0.8;
}

@keyframes float {
    0% {
        transform: translateY(0) scale(1);
        opacity: 0.8;
    }
    100% {
        transform: translateY(-100vh) scale(1.5);
        opacity: 0;
    }
}