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

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(to right, #ff9a9e, #fad0c4);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    position: relative;
}

.container {
    text-align: center;
    z-index: 2;
    padding: 20px;
}

.birthday-card {
    background-color: rgba(255, 255, 255, 0.8);
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    padding: 40px;
    max-width: 500px;
    margin: 0 auto;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(5px);
}

.title {
    font-family: 'Dancing Script', cursive;
    font-size: 3.5rem;
    color: #ff6b8b;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
    animation: glow 2s ease-in-out infinite alternate;
}

.birthday-message {
    font-size: 1.2rem;
    margin-bottom: 30px;
    color: #555;
}

.btn {
    background: linear-gradient(45deg, #ff6b8b, #ff8e53);
    border: none;
    color: white;
    padding: 12px 30px;
    font-size: 1.1rem;
    border-radius: 50px;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 5px 15px rgba(255, 107, 139, 0.4);
    font-weight: 500;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(255, 107, 139, 0.6);
}

/* Collage Effect Styles */
.collage-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 3;
    overflow: hidden;
}

.collage-item {
    position: absolute;
    opacity: 0;
    transform: scale(0.8);
    transition: opacity 1s ease, transform 1s ease;
    filter: drop-shadow(0 0 10px rgba(255, 107, 139, 0.5));
    pointer-events: none;
    z-index: 1;
}

.collage-item.visible {
    opacity: 0.85;
    transform: scale(1);
}

.heart-frame {
    position: relative;
    width: 120px;
    height: 120px;
    -webkit-mask-image: url('assets/images/heart-frame.svg');
    mask-image: url('assets/images/heart-frame.svg');
    -webkit-mask-size: 100% 100%;
    mask-size: 100% 100%;
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    -webkit-mask-position: center;
    mask-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: black;
    padding: 8px;
    overflow: hidden;
    border: 3px solid #ff6b8b;
    box-shadow: 0 0 10px rgba(255, 107, 139, 0.8);
}

.heart-frame::after {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    border: 4px solid #ff6b8b;
    z-index: 3;
    pointer-events: none;
    opacity: 1;
    transition: opacity 0.5s ease;
    -webkit-mask-image: url('assets/images/heart-frame.svg');
    mask-image: url('assets/images/heart-frame.svg');
    -webkit-mask-size: 100% 100%;
    mask-size: 100% 100%;
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    -webkit-mask-position: center;
    mask-position: center;
}

.collage-item.visible .heart-frame::after {
    opacity: 1;
}

.heart-frame img {
    width: 90%;
    height: 90%;
    object-fit: contain;
    transform: scale(1);
    transition: transform 0.5s ease, filter 0.5s ease;
    filter: drop-shadow(0 0 5px rgba(255, 255, 255, 0.3));
}

.heart-frame::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at center, transparent 60%, rgba(255, 107, 139, 0.2) 100%);
    pointer-events: none;
    z-index: 2;
}

.collage-item.visible .heart-frame img {
    transform: scale(1.05);
    filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.5));
}

.heart-glow {
    position: absolute;
    top: -10px;
    left: -10px;
    right: -10px;
    bottom: -10px;
    background: radial-gradient(ellipse at center, rgba(255, 107, 139, 0.4) 0%, rgba(255, 107, 139, 0) 70%);
    border-radius: 50%;
    z-index: -1;
    animation: pulse 3s infinite alternate;
}

/* Ripple effect */
.heart-ripple {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: transparent;
    border: 2px solid rgba(255, 107, 139, 0.5);
    z-index: -1;
    opacity: 0;
    pointer-events: none;
}

.heart-ripple-1 {
    animation: ripple 3s infinite;
}

.heart-ripple-2 {
    animation: ripple 3s infinite 1s;
}

.heart-ripple-3 {
    animation: ripple 3s infinite 2s;
}

@keyframes ripple {
    0% {
        width: 100%;
        height: 100%;
        opacity: 0.7;
    }
    100% {
        width: 300%;
        height: 300%;
        opacity: 0;
    }
}

@keyframes pulse {
    0% {
        opacity: 0.5;
        transform: scale(0.95);
    }
    100% {
        opacity: 0.8;
        transform: scale(1.05);
    }
}

.btn:active {
    transform: translateY(1px);
}

/* Hearts Animation */
.hearts-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}

.heart {
    position: absolute;
    width: 20px;
    height: 20px;
    background: url('assets/images/heart.svg') no-repeat;
    background-size: contain;
    pointer-events: none;
    animation: float 5s ease-in-out infinite;
    opacity: 0.8;
}

/* Audio Controls */
.audio-control {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10;
}

.audio-control button {
    background: rgba(255, 255, 255, 0.7);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s;
}

.audio-control button:hover {
    background: rgba(255, 255, 255, 0.9);
    transform: scale(1.1);
}

.hidden {
    display: none;
}

/* Animations */
@keyframes glow {
    from {
        text-shadow: 0 0 5px #fff, 0 0 10px #fff, 0 0 15px #ff6b8b, 0 0 20px #ff6b8b;
    }
    to {
        text-shadow: 0 0 10px #fff, 0 0 20px #fff, 0 0 30px #ff6b8b, 0 0 40px #ff6b8b;
    }
}

@keyframes float {
    0% {
        transform: translateY(0) rotate(0deg);
        opacity: 0.8;
    }
    50% {
        transform: translateY(-100px) rotate(180deg);
        opacity: 0.4;
    }
    100% {
        transform: translateY(-200px) rotate(360deg);
        opacity: 0;
    }
}

/* Responsive Design */
@media (max-width: 600px) {
    .birthday-card {
        padding: 30px 20px;
    }
    
    .title {
        font-size: 2.5rem;
    }
    
    .birthday-message {
        font-size: 1rem;
    }
    
    .btn {
        padding: 10px 25px;
        font-size: 1rem;
    }
}