body {
    margin: 0;
    height: 100vh;
    background: linear-gradient(to bottom, #0f2027, #203a43, #2c5364);
    overflow: hidden;
}

.snow-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 2;
    perspective: 1000px;
}

.snow {
    position: absolute;
    width: 10px;
    height: 10px;
    background: white;
    border-radius: 50%;
    filter: blur(1px);
    animation: snowfall linear forwards;
}

@keyframes snowfall {
    from {
        transform: translateY(-10px) rotate(0deg);
    }
    to {
        transform: translateY(100vh) rotate(360deg);
    }
}

.christmas-content {
    position: absolute;
    top: 60%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    width: 100%;
}

.christmas-title {
    position: relative;
    transform: none;
    margin-bottom: 20px;
    font-family: "Mountains of Christmas", cursive;
    font-size: 3rem;
    color: #fff;
    text-shadow: 0 0 10px #ff0000, 0 0 20px #ff0000;
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from {
        text-shadow: 0 0 10px #ff0000, 0 0 20px #ff0000;
    }
    to {
        text-shadow: 0 0 20px #ff0000, 0 0 30px #ff0000, 0 0 40px #ff0000;
    }
}

.music-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 15px;
    font-size: 30px;
    background: rgba(0, 0, 0, 0.3);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    transition: transform 0.3s;
    z-index: 1000;
}

.music-toggle:hover {
    transform: scale(1.1);
    background: rgba(0, 0, 0, 0.5);
}

.christmas-tree {
    position: relative;
    bottom: auto;
    left: auto;
    transform: none;
}

.tree {
    right: 1%;
    position: relative;
    width: 300px;
    height: 400px;
    margin: 0 auto;
    display: flex;
    justify-content: center;
}

.pine-tree-img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.star-top {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 40px;
    color: gold;
    animation: starGlow 2s infinite alternate;
    z-index: 2;
}

.bells-container {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.ornament {
    position: absolute;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    animation: twinkle 1.5s infinite alternate;
}

.bell {
    position: absolute;
    width: 20px;
    height: 20px;
    background: gold;
    border-radius: 50% 50% 45% 45%;
    animation: bellRing 2s infinite;
}

.bell::after {
    content: "";
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%);
    width: 6px;
    height: 6px;
    background: #444;
    border-radius: 50%;
}

@keyframes bellRing {
    0%,
    100% {
        transform: rotate(0);
    }
    25% {
        transform: rotate(15deg);
    }
    75% {
        transform: rotate(-15deg);
    }
}

@keyframes starGlow {
    from {
        filter: drop-shadow(0 0 2px gold);
    }
    to {
        filter: drop-shadow(0 0 10px gold);
    }
}

.red {
    background: #ff4444;
}
.gold {
    background: #ffdd44;
}
.silver {
    background: #dddddd;
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: white;
    border-radius: 50%;
    animation: twinkle 1s infinite alternate;
}

@keyframes twinkle {
    from {
        opacity: 0.2;
    }
    to {
        opacity: 1;
    }
}

.gift {
    position: fixed;
    width: 50px;
    height: 50px;
    background: url("https://firebasestorage.googleapis.com/v0/b/webai-54992.appspot.com/o/Gift_Flat_Icon_Vector.svg?alt=media&token=8bb72a2d-183c-462b-a1b8-e42af9bf52e0")
        no-repeat;
    background-size: contain;
    cursor: pointer;
    transition: transform 0.3s;
    z-index: 100;
}

.gift:hover {
    transform: scale(1.2) rotate(10deg);
}

.gift-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(255, 255, 255, 0.95);
    padding: 20px 30px;
    border-radius: 15px;
    box-shadow: 0 0 30px rgba(255, 0, 0, 0.3);
    font-size: 1.2em;
    color: #333;
    display: none;
    z-index: 2000;
    animation: popup 0.5s ease-out;
    text-align: center;
}

@keyframes popup {
    from {
        transform: translate(-50%, -50%) scale(0);
    }
    to {
        transform: translate(-50%, -50%) scale(1);
    }
}

@keyframes fall {
    0% {
        transform: translateY(-10px) translateZ(0) rotate(0deg);
    }
    100% {
        transform: translateY(100vh) translateZ(500px) rotate(360deg);
    }
}

.light {
    position: absolute;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    animation: blink 1s infinite alternate;
}

@keyframes blink {
    from {
        opacity: 0.3;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1.2);
    }
}

/* Hiệu ứng mây */
.clouds {
    position: fixed;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.cloud {
    position: absolute;
    width: 100px;
    height: auto;
    opacity: 0.6;
    filter: brightness(0.8);
}

@keyframes float {
    from {
        left: -150px;
    }
    to {
        left: 100%;
    }
}

/* Hiệu ứng pháo hoa */
.fireworks-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1000;
    overflow: hidden;
}

.firework-particle {
    position: absolute;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    pointer-events: none;
    opacity: 1;
    animation: fadeOut 1s forwards;
}

@keyframes fadeOut {
    to {
        opacity: 0;
    }
}

/* Hiệu ứng particle chuột */
.mouse-particle {
    position: fixed;
    width: 10px;
    height: 10px;
    background: #1fa800;
    border-radius: 50%;
    pointer-events: none;
    animation: sparkle 1s linear forwards;
}

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

/* Hiệu ứng cây thông */
.tree {
    transition: transform 0.3s;
}

.tree.shake {
    animation: shakeTree 0.5s ease-in-out;
}

@keyframes shakeTree {
    0%,
    100% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-5px) rotate(-5deg);
    }
    75% {
        transform: translateX(5px) rotate(5deg);
    }
}

.star-top {
    position: absolute;
    top: -3%;
    left: 53%;
    transform: translateX(-50%);
    font-size: 24px;
    animation: starTwinkle 1.5s infinite alternate;
}

@keyframes starTwinkle {
    from {
        opacity: 0.5;
        transform: translateX(-50%) scale(0.8);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) scale(1.2);
    }
}

/* Hiệu ứng ánh sáng ông già Noel */
.santa-container {
    position: fixed;
    top: 20%;
    left: -200px;
    animation: flyAcross 15s linear infinite;
    z-index: 1000;
    display: flex;
    align-items: center;
}

.santa {
    width: 200px;
    height: auto;
    margin-right: -30px;
    z-index: 1;
}

@keyframes flyAcross {
    0% {
        transform: translateX(0) translateY(0);
    }
    25% {
        transform: translateX(calc(25vw)) translateY(-30px);
    }
    50% {
        transform: translateX(calc(50vw)) translateY(0);
    }
    75% {
        transform: translateX(calc(75vw)) translateY(-30px);
    }
    100% {
        transform: translateX(calc(100vw + 400px)) translateY(0);
    }
}

/* Hiệu ứng countdown */
.countdown {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0, 0, 0, 0.5);
    padding: 10px 20px;
    border-radius: 20px;
    color: white;
    font-size: 1.2em;
    z-index: 1000;
}

.countdown span {
    color: #ff4444;
    font-weight: bold;
    margin: 0 5px;
}

/* Media Queries cho responsive */
@media screen and (max-width: 768px) {
    .christmas-title {
        font-size: 3rem; /* Giảm kích thước chữ trên mobile */
    }

    .countdown {
        font-size: 1em;
        padding: 8px 15px;
        width: 90%;
        text-align: center;
    }

    .tree {
        width: 200px;
        height: 300px;
        right: 3%;
    }

    .star-top {
        font-size: 30px;
        top: -15px;
    }

    .santa {
        width: 300px;
    }

    .music-toggle {
        padding: 10px;
        font-size: 24px;
    }

    .cloud {
        width: 60px;
    }

    .fireworks-container {
        width: 100vw;
        height: 50vh;
    }

    .christmas-content {
        width: 90%;
    }
}

@media screen and (max-width: 480px) {
    .christmas-title {
        font-size: 2rem;
    }

    .countdown {
        font-size: 0.9em;
    }

    .tree {
        width: 150px;
        height: 250px;
        right: 3%;
    }

    .star-top {
        font-size: 24px;
        top: -12px;
    }

    .santa {
        width: 300px;
    }

    .cloud {
        width: 40px;
    }

    .gift-popup {
        width: 80%;
        font-size: 1em;
        padding: 15px;
    }
}

.tiktok-logo {
    position: fixed;
    bottom: 15px;
    left: 15px;
    z-index: 1000;
}

.tiktok-logo img {
    width: 35px;
    height: auto;
}
/* ... (giữ nguyên phần code CSS cũ) ... */

/* === CSS NỀN GIẤY TRẮNG VÀ NÚT ĐÓNG CHO POPUP === */
.gift-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: #ffffff; /* Nền giấy trắng */
    padding: 40px 30px 30px; /* Thêm padding trên để chừa chỗ cho nút đóng */
    border-radius: 15px;
    box-shadow: 0 0 30px rgba(255, 0, 0, 0.5); /* Shadow đậm hơn */
    font-size: 1.2em;
    color: #333;
    display: none;
    z-index: 2000;
    animation: popup 0.5s ease-out;
    text-align: center;
    max-width: 400px; /* Giới hạn chiều rộng thư */
    border: 1px solid #ccc;
    font-family: "Times New Roman", serif; /* Font chữ trang trọng hơn */
    position: relative; /* Quan trọng cho nút đóng */
}

.popup-close-btn {
    position: absolute;
    top: 10px;
    right: 15px;
    background: none;
    border: none;
    font-size: 20px;
    font-weight: bold;
    cursor: pointer;
    color: #555;
    transition: color 0.2s;
}

.popup-close-btn:hover {
    color: #ff0000;
}

/* Đảm bảo phần chữ trong popup dễ đọc */
.gift-popup p {
    line-height: 1.6;
    margin: 10px 0;
    white-space: pre-wrap; /* Giữ định dạng xuống dòng trong JS */
    text-align: left;
}

/* === CSS NỀN GIẤY TRẮNG VÀ NÚT ĐÓNG CHO POPUP === */
.gift-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: #ffffff; /* Nền giấy trắng */
    padding: 40px 30px 30px; /* Thêm padding trên để chừa chỗ cho nút đóng */
    border-radius: 15px;
    box-shadow: 0 0 30px rgba(255, 0, 0, 0.5); /* Shadow đậm hơn */
    font-size: 1.2em;
    color: #333;
    display: none;
    z-index: 2000;
    animation: popup 0.5s ease-out;
    text-align: center;
    max-width: 400px; /* Giới hạn chiều rộng thư */
    border: 1px solid #ccc;
    font-family: "Times New Roman", serif; /* Font chữ trang trọng hơn */
    position: relative; /* Quan trọng cho nút đóng */
}

.popup-close-btn {
    position: absolute;
    top: 10px;
    right: 15px;
    background: none;
    border: none;
    font-size: 20px;
    font-weight: bold;
    cursor: pointer;
    color: #555;
    transition: color 0.2s;
}

.popup-close-btn:hover {
    color: #ff0000;
}

/* Đảm bảo phần chữ trong popup dễ đọc */
.gift-popup p {
    line-height: 1.6;
    margin: 10px 0;
    white-space: pre-wrap; /* Giữ định dạng xuống dòng trong JS */
    text-align: left;
}
/* Thêm vào style.css */
/* === CSS NỀN GIẤY TRẮNG VÀ NÚT ĐÓNG CHO POPUP === */
.gift-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: #ffffff;
    padding: 40px 30px 30px;
    border-radius: 15px;
    box-shadow: 0 0 30px rgba(255, 0, 0, 0.5);
    font-size: 1.2em;
    color: #333;
    display: none;
    z-index: 2000;
    animation: popup 0.5s ease-out;
    text-align: center;
    max-width: 400px;
    border: 1px solid #ccc;
    font-family: "Times New Roman", serif;
    position: relative;
}

.popup-close-btn {
    position: absolute;
    top: 10px;
    right: 15px;
    background: none;
    border: none;
    font-size: 20px;
    font-weight: bold;
    cursor: pointer;
    color: #555;
    transition: color 0.2s;
}

.popup-close-btn:hover {
    color: #ff0000;
}

.gift-popup p {
    line-height: 1.6;
    margin: 10px 0;
    white-space: pre-wrap;
    text-align: left;
}
.gift-popup p {
    font-family: "Mali", sans-serif;
    font-size: 20px;
    line-height: 1.7;
    text-align: left;
}
@font-face {
    font-family: "Mali";
    src: url("./font/Mali.ttf") format("truetype");
    font-weight: normal;
    font-style: normal;
}
/* ===== PERFORMANCE ===== */
.snow,
.gift,
.firework-particle,
.santa-container {
    will-change: transform;
}

/* ===== iOS SAFARI FIX ===== */
@supports (-webkit-touch-callout: none) {
    .popupLayer {
        backdrop-filter: none !important;
        background: rgba(0, 0, 0, 0.45);
    }
}

/* ===== SNOW ===== */
.snow {
    position: fixed;
    background: white;
    border-radius: 50%;
    pointer-events: none;
}

/* ===== FIREWORK ===== */
.firework-particle {
    position: fixed;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: yellow;
}

/* ===== GIFT ===== */
.gift {
    position: fixed;
    background-size: contain;
    background-repeat: no-repeat;
    cursor: pointer;
}