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

body {
    font-family: 'Montserrat', sans-serif;
    background: linear-gradient(135deg, #ff9a9e 0%, #fad0c4 100%);
    min-height: 100vh;
    color: #333;
    position: relative;
    overflow-x: hidden;
}

/* Hiệu ứng sparkles */
.sparkles {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    pointer-events: none;
}

.sparkles::before,
.sparkles::after {
    content: '';
    position: absolute;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 0 10px #fff;
    animation: sparkle 2s linear infinite;
}

.sparkles::before {
    top: 20%;
    left: 20%;
    animation-delay: 0s;
}

.sparkles::after {
    top: 60%;
    left: 80%;
    animation-delay: 1s;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Màn hình chào */
.welcome-screen {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    background: linear-gradient(135deg, #ff9a9e 0%, #fad0c4 100%);
    position: relative;
    overflow: hidden;
}

.welcome-screen h1 {
    font-family: 'Great Vibes', cursive;
    font-size: 5rem;
    color: #ff4b6e;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    background: linear-gradient(45deg, #ff4b6e, #ff9a9e);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
}

.welcome-screen h2 {
    font-family: 'Playfair Display', serif;
    font-size: 3rem;
    color: #666;
    margin-bottom: 40px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

#startBtn {
    padding: 15px 30px;
    font-size: 1.2rem;
    background: linear-gradient(45deg, #ff4b6e, #ff9a9e);
    color: white;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(255, 75, 110, 0.3);
    position: relative;
    overflow: hidden;
}

#startBtn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: 0.5s;
}

#startBtn:hover::before {
    left: 100%;
}

#startBtn:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(255, 75, 110, 0.4);
}

/* Banner */
.banner {
    text-align: center;
    padding: 50px 0;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 40px;
}

.banner-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
}

.banner h1 {
    font-family: 'Great Vibes', cursive;
    font-size: 4rem;
    background: linear-gradient(45deg, #ff4b6e, #ff9a9e);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
    z-index: 2;
    margin-bottom: 20px;
}

.banner h2 {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem;
    color: #666;
    position: relative;
    z-index: 2;
}

/* Bánh kem */
.cake-container {
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.cake {
    width: 100%;
    height: auto;
    aspect-ratio: 1;
    position: relative;
    transform-style: preserve-3d;
    perspective: 1000px;
}

.cake-layers {
    position: relative;
    width: 100%;
    height: 100%;
}

.layer {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    background: linear-gradient(to right, #ff9a9e, #fad0c4);
    transition: all 0.3s ease;
}

.layer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0) 50%);
    border-radius: 15px;
}

.layer1 {
    bottom: 0;
    width: 90%;
    height: 25%;
}

.layer2 {
    bottom: 25%;
    width: 80%;
    height: 25%;
}

.layer3 {
    bottom: 50%;
    width: 70%;
    height: 25%;
}

.candles {
    position: absolute;
    bottom: 70%;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8%;
    width: 60%;
    justify-content: center;
}

.candle {
    position: relative;
    width: 8%;
    height: 15%;
    background: linear-gradient(to right, #fff, #f8f8f8);
    border-radius: 6px;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

.candle::before {
    content: '';
    position: absolute;
    top: -5px;
    left: 50%;
    transform: translateX(-50%);
    width: 8px;
    height: 8px;
    background: #ff4b6e;
    border-radius: 50%;
    box-shadow: 0 0 10px #ff4b6e;
}

.flame {
    position: absolute;
    top: -8%;
    left: 50%;
    transform: translateX(-50%);
    width: 8px;
    height: 12px;
    background: linear-gradient(to top, #ff4b6e, #ff9a9e);
    border-radius: 50% 50% 20% 20%;
    opacity: 0;
    transition: opacity 0.3s ease;
    filter: blur(1px);
}

.flame.active {
    opacity: 1;
    animation: flicker 1s ease-in-out infinite;
}

@keyframes flicker {
    0%, 100% {
        transform: translateX(-50%) scale(1);
        box-shadow: 0 0 20px #ff4b6e;
    }
    50% {
        transform: translateX(-50%) scale(1.1);
        box-shadow: 0 0 30px #ff4b6e;
    }
}

/* Thêm hiệu ứng cho bánh kem */
.cake::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0) 70%);
    pointer-events: none;
}

.layer::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0) 50%);
    border-radius: 15px;
}

/* Hiệu ứng khi countdown kết thúc */
.cake.celebrate .layer {
    animation: celebrate 1s ease-in-out;
}

@keyframes celebrate {
    0% {
        transform: translateX(-50%) scale(1);
    }
    50% {
        transform: translateX(-50%) scale(1.1);
    }
    100% {
        transform: translateX(-50%) scale(1);
    }
}

/* Lời chúc */
.wishes {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    padding: 50px 0;
}

.wish-card {
    background: rgba(255, 255, 255, 0.9);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.card-decoration {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, #ff4b6e, #ff9a9e);
}

.wish-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.wish-card h3 {
    font-family: 'Playfair Display', serif;
    color: #ff4b6e;
    margin-bottom: 15px;
    font-size: 1.8rem;
}

.wish-card p {
    font-family: 'Montserrat', sans-serif;
    color: #666;
    line-height: 1.8;
    font-size: 1.1rem;
}

/* Gallery */
.gallery {
    padding: 50px 0;
    text-align: center;
}

.gallery h3 {
    font-family: 'Playfair Display', serif;
    color: #ff4b6e;
    margin-bottom: 30px;
    font-size: 2.5rem;
}

.photo-grid {
    display: flex;
    justify-content: center;
    gap: 20px;
    padding: 0 20px;
    flex-wrap: nowrap;
}

.photo-item {
    flex: 1;
    max-width: 300px;
    min-width: 200px;
    overflow: hidden;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    position: relative;
}

.photo-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(255, 75, 110, 0.2), rgba(255, 154, 158, 0.2));
    opacity: 0;
    transition: 0.3s ease;
}

.photo-item:hover::before {
    opacity: 1;
}

.photo-item:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.photo-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.3s ease;
}

/* Countdown */
.countdown {
    text-align: center;
    padding: 50px 0;
}

.countdown h3 {
    font-family: 'Playfair Display', serif;
    color: #ff4b6e;
    margin-bottom: 30px;
    font-size: 2.5rem;
}

.countdown-timer {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.time-block {
    background: rgba(255, 255, 255, 0.9);
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    min-width: 120px;
    transition: all 0.3s ease;
}

.time-block:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.time-block span {
    display: block;
}

.time-block span:first-child {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem;
    color: #ff4b6e;
    font-weight: bold;
}

.time-block .label {
    font-family: 'Montserrat', sans-serif;
    color: #666;
    font-size: 1rem;
    margin-top: 5px;
}

/* Gift section */
.gift-section h3 {
    font-family: 'Playfair Display', serif;
    color: #ff4b6e;
    margin-bottom: 30px;
    font-size: 2.5rem;
}

.gift-message h4 {
    font-family: 'Great Vibes', cursive;
    color: #ff4b6e;
    font-size: 2rem;
    margin-bottom: 20px;
}

/* Phần quà tặng */
.gift-section {
    text-align: center;
    padding: 50px 0;
}

.gift-box {
    width: 200px;
    height: 200px;
    margin: 0 auto;
    position: relative;
    cursor: pointer;
    transform-style: preserve-3d;
    transition: all 0.5s ease;
}

.gift-box:hover {
    transform: scale(1.05);
}

.gift-box.disappear {
    transform: scale(0);
    opacity: 0;
}

.gift-body {
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, #ff4b6e, #ff9a9e);
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    position: relative;
}

.gift-lid {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 120%;
    height: 40px;
    background: linear-gradient(45deg, #ff4b6e, #ff9a9e);
    border-radius: 10px;
    transition: transform 0.5s ease;
}

.gift-bow {
    position: absolute;
    top: -30px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 60px;
}

.gift-bow::before,
.gift-bow::after {
    content: '';
    position: absolute;
    width: 30px;
    height: 50px;
    background: #ff4b6e;
    border-radius: 50% 50% 0 0;
}

.gift-bow::before {
    left: 0;
    transform: rotate(-30deg);
}

.gift-bow::after {
    right: 0;
    transform: rotate(30deg);
}

.gift-box.open .gift-lid {
    transform: translateX(-50%) rotateX(180deg);
}

.gift-message {
    margin-top: 30px;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.5s ease;
}

.gift-message.show {
    opacity: 1;
    transform: translateY(0);
}

.gift-image {
    max-width: 400px;
    margin: 0 auto;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.gift-image img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.3s ease;
}

.gift-image img:hover {
    transform: scale(1.05);
}

/* Thêm hiệu ứng cho quà */
.gift-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0) 50%);
    border-radius: 10px;
    pointer-events: none;
}

.gift-box::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 90%;
    height: 90%;
    border: 2px solid rgba(255,255,255,0.2);
    border-radius: 8px;
    pointer-events: none;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .container {
        padding: 15px;
    }

    .welcome-screen h1 {
        font-size: 4.5rem;
    }

    .welcome-screen h2 {
        font-size: 2.8rem;
    }

    .banner {
        padding: 40px 0;
        gap: 30px;
    }

    .banner-content {
        margin-bottom: 30px;
    }

    .cake-container {
        max-width: 250px;
    }

    .banner h1 {
        font-size: 3.5rem;
    }

    .banner h2 {
        font-size: 2.2rem;
    }

    .photo-grid {
        gap: 15px;
    }

    .photo-item {
        max-width: 250px;
        min-width: 180px;
    }

    .photo-item img {
        height: 180px;
    }
}

@media (max-width: 992px) {
    .welcome-screen h1 {
        font-size: 4rem;
    }

    .welcome-screen h2 {
        font-size: 2.5rem;
    }

    .wish-card h3 {
        font-size: 1.6rem;
    }

    .wish-card p {
        font-size: 1rem;
    }

    .gallery h3,
    .countdown h3,
    .gift-section h3 {
        font-size: 2.2rem;
    }

    .time-block {
        min-width: 100px;
        padding: 15px;
    }

    .time-block span:first-child {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .welcome-screen h1 {
        font-size: 3.5rem;
    }

    .welcome-screen h2 {
        font-size: 2rem;
    }

    .banner {
        padding: 30px 0;
        gap: 25px;
    }

    .banner-content {
        margin-bottom: 25px;
    }

    .cake-container {
        max-width: 200px;
    }

    .candles {
        bottom: 180px;
        gap: 15px;
    }

    .candle {
        width: 8px;
        height: 25px;
    }

    .wishes {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .countdown-timer {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .time-block {
        min-width: 90px;
        padding: 12px;
    }

    .time-block span:first-child {
        font-size: 1.8rem;
    }

    .gift-box {
        width: 150px;
        height: 150px;
    }

    .gift-image {
        max-width: 300px;
    }

    .photo-grid {
        gap: 10px;
    }

    .photo-item {
        max-width: 200px;
        min-width: 150px;
    }

    .photo-item img {
        height: 150px;
    }
}

@media (max-width: 576px) {
    .welcome-screen h1 {
        font-size: 3rem;
    }

    .welcome-screen h2 {
        font-size: 1.8rem;
    }

    .banner {
        padding: 25px 0;
        gap: 20px;
    }

    .banner-content {
        margin-bottom: 20px;
    }

    .cake-container {
        max-width: 180px;
    }

    .candles {
        bottom: 160px;
        gap: 12px;
    }

    .candle {
        width: 7px;
        height: 22px;
    }

    .wish-card {
        padding: 20px;
    }

    .wish-card h3 {
        font-size: 1.4rem;
    }

    .wish-card p {
        font-size: 0.9rem;
    }

    .gallery h3,
    .countdown h3,
    .gift-section h3 {
        font-size: 2rem;
    }

    .countdown-timer {
        gap: 10px;
    }

    .time-block {
        min-width: 80px;
        padding: 10px;
    }

    .time-block span:first-child {
        font-size: 1.6rem;
    }

    .time-block .label {
        font-size: 0.9rem;
    }

    .gift-box {
        width: 120px;
        height: 120px;
    }

    .gift-image {
        max-width: 250px;
    }

    .gift-message h4 {
        font-size: 1.8rem;
    }

    .photo-grid {
        gap: 8px;
    }

    .photo-item {
        max-width: 150px;
        min-width: 120px;
    }

    .photo-item img {
        height: 120px;
    }
}

@media (max-width: 400px) {
    .welcome-screen h1 {
        font-size: 2.5rem;
    }

    .welcome-screen h2 {
        font-size: 1.5rem;
    }

    .banner {
        padding: 20px 0;
        gap: 15px;
    }

    .banner-content {
        margin-bottom: 15px;
    }

    .cake-container {
        max-width: 150px;
    }

    .candles {
        bottom: 140px;
        gap: 10px;
    }

    .candle {
        width: 6px;
        height: 20px;
    }

    .wish-card h3 {
        font-size: 1.3rem;
    }

    .wish-card p {
        font-size: 0.85rem;
    }

    .gallery h3,
    .countdown h3,
    .gift-section h3 {
        font-size: 1.8rem;
    }

    .time-block {
        min-width: 70px;
        padding: 8px;
    }

    .time-block span:first-child {
        font-size: 1.4rem;
    }

    .time-block .label {
        font-size: 0.8rem;
    }

    .gift-box {
        width: 100px;
        height: 100px;
    }

    .gift-image {
        max-width: 200px;
    }

    .gift-message h4 {
        font-size: 1.6rem;
    }

    .photo-grid {
        gap: 5px;
    }

    .photo-item {
        max-width: 120px;
        min-width: 100px;
    }

    .photo-item img {
        height: 100px;
    }
}

/* Fix cho các thiết bị có chiều cao màn hình nhỏ */
@media (max-height: 600px) {
    .welcome-screen {
        height: auto;
        min-height: 100vh;
        padding: 40px 0;
    }

    .welcome-screen h1 {
        font-size: 2.5rem;
        margin-bottom: 15px;
    }

    .welcome-screen h2 {
        font-size: 1.8rem;
        margin-bottom: 30px;
    }

    .banner {
        padding: 15px 0;
    }

    .banner-content {
        margin-bottom: 10px;
    }

    .cake {
        margin-top: 10px;
    }

    .banner h1 {
        font-size: 2.5rem;
        margin-bottom: 5px;
    }

    .banner h2 {
        font-size: 1.8rem;
        margin-bottom: 10px;
    }

    .cake {
        width: 150px;
        height: 150px;
        margin: 5px auto;
    }
}

/* Fix cho các thiết bị có tỷ lệ màn hình khác thường */
@media (aspect-ratio: 1/1) {
    .welcome-screen h1 {
        font-size: 3rem;
    }

    .welcome-screen h2 {
        font-size: 2rem;
    }

    .banner h1 {
        font-size: 2.8rem;
    }

    .banner h2 {
        font-size: 1.8rem;
    }
}

/* Fix cho các thiết bị có màn hình rộng */
@media (min-width: 1400px) {
    .container {
        max-width: 1400px;
    }

    .welcome-screen h1 {
        font-size: 5.5rem;
    }

    .welcome-screen h2 {
        font-size: 3.5rem;
    }

    .banner h1 {
        font-size: 4.5rem;
    }

    .banner h2 {
        font-size: 3rem;
    }

    .cake {
        width: 350px;
        height: 350px;
    }
}

/* Fix cho các thiết bị có pixel ratio cao */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    .welcome-screen h1,
    .banner h1,
    .wish-card h3,
    .gallery h3,
    .countdown h3,
    .gift-section h3 {
        -webkit-font-smoothing: antialiased;
        -moz-osx-font-smoothing: grayscale;
    }
}

/* Fix cho các thiết bị có màn hình cảm ứng */
@media (hover: none) {
    .wish-card:hover,
    .photo-item:hover,
    .time-block:hover,
    .gift-box:hover {
        transform: none;
    }

    .photo-item:active,
    .gift-box:active {
        transform: scale(0.98);
    }
}

/* Fix cho các thiết bị có dark mode */
@media (prefers-color-scheme: dark) {
    body {
        background: linear-gradient(135deg, #2c3e50 0%, #4a69bd 100%);
        color: #fff;
    }

    .wish-card,
    .time-block {
        background: rgba(255, 255, 255, 0.1);
    }

    .wish-card p,
    .time-block .label {
        color: #fff;
    }
}