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

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #ff6b9d, #c44569, #f8b500);
    background-size: 400% 400%;
    animation: gradientShift 8s ease infinite;
    min-height: 100vh;
    overflow-x: hidden;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    position: relative;
}

.heart-container {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    z-index: 10;
}

#heartCanvas {
    cursor: crosshair;
    background: transparent;
}

.instruction {
    margin-top: 20px;
    font-size: 1.2rem;
    color: white;
    text-align: center;
    font-weight: bold;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.05); opacity: 0.8; }
}

.love-message {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
    font-size: 2rem;
    opacity: 0;
    visibility: hidden;
    transition: all 1s ease;
    z-index: 100;
    text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.7);
}

.love-message.show {
    opacity: 1;
    visibility: visible;
    animation: loveMessageAnimation 3s ease;
}

@keyframes loveMessageAnimation {
    0% { transform: translate(-50%, -50%) scale(0.5); opacity: 0; }
    50% { transform: translate(-50%, -50%) scale(1.2); opacity: 1; }
    100% { transform: translate(-50%, -50%) scale(1); opacity: 1; }
}

.heart-rain {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 50;
}

.falling-heart {
    position: absolute;
    font-size: 20px;
    color: #ff6b9d;
    animation: fall linear infinite;
    opacity: 0.8;
}

@keyframes fall {
    0% {
        transform: translateY(-100px) rotate(0deg);
        opacity: 1;
    }
    100% {
        transform: translateY(100vh) rotate(360deg);
        opacity: 0;
    }
}

.heart-shake {
    animation: heartShake 0.5s infinite;
}

@keyframes heartShake {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    25% { transform: translate(-2px, -2px) rotate(-1deg); }
    50% { transform: translate(2px, -2px) rotate(1deg); }
    75% { transform: translate(-2px, 2px) rotate(-1deg); }
}

.heart-explode {
    animation: heartExplode 1s ease-out forwards;
}

@keyframes heartExplode {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.5); opacity: 0.8; }
    100% { transform: scale(3); opacity: 0; }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    #heartCanvas {
        max-width: 90vw;
        max-height: 60vh;
    }
    
    .instruction {
        font-size: 1rem;
        margin-top: 15px;
    }
    
    .love-message {
        font-size: 1.5rem;
        padding: 0 20px;
    }
    
    .falling-heart {
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .love-message {
        font-size: 1.2rem;
    }
    
    .instruction {
        font-size: 0.9rem;
    }
    
    .falling-heart {
        font-size: 14px;
    }
}

@media (max-height: 600px) {
    #heartCanvas {
        max-height: 50vh;
    }
    
    .container {
        padding: 5px;
    }
}