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

body {
    background: #fff;
}

.cloud-door {
    position: fixed;
    top: 0;
    width: 50vw;
    height: 100vh;
    transition: transform 4s ease-in-out;
    z-index: 9999;
    background-size: 200% 100%;
    background-repeat: no-repeat;
    background-position: center;
}

.left-door {
    left: 0;
    transform: translateX(0);
    background-image: url("https://w.ladicdn.com/675faed0e377b9028f9ce15b/4b64f6c76e0ef5477840ead5a6961b54-20250512044609-q-vtt.jpg");
    background-size: 200% 100%;
    /* Phóng to để mỗi cửa chiếm 1 nửa */
    background-position: left center;
}

.right-door {
    right: 0;
    transform: translateX(0);
    background-image: url("https://w.ladicdn.com/675faed0e377b9028f9ce15b/4b64f6c76e0ef5477840ead5a6961b54-20250512044609-q-vtt.jpg");
    background-size: 200% 100%;
    background-position: right center;
}

.open .left-door {
    transform: translateX(-100%);
}

.open .right-door {
    transform: translateX(100%);
}

.content {
    position: relative;
    z-index: 10;
    text-align: center;
    font-size: 24px;
    font-weight: bold;
    padding-top: 50vh;
    opacity: 0;
    transition: opacity 2s ease-in-out 4s;
}

.open .content {
    opacity: 1;
}

@media(min-width: 768px) {
    .left-door {
        background-image: url("https://w.ladicdn.com/5c728619c417ab07e5194baa/z6587626478947_d7b503e4ce70ca497f8f07a3a196b6dd-20250510080856-_acyw.jpg");
    }

    .right-door {
        background-image: url("https://w.ladicdn.com/5c728619c417ab07e5194baa/z6587626478947_d7b503e4ce70ca497f8f07a3a196b6dd-20250510080856-_acyw.jpg");
    }
}

#music-toggle {
    position: fixed;
    bottom: 15px;
    left: 15px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #fff;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

#music-toggle:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

#music-toggle img {
    width: 25px;
    height: 25px;
    pointer-events: none;
}

/* Hiệu ứng rung, xoay và phát sáng đỏ đậm */
.vibrating {
    animation: pulse 1.2s infinite, rotate 4s linear infinite, glow 2s ease-in-out infinite;
    box-shadow: 0 0 15px rgba(139, 0, 0, 0.6), 0 0 25px rgba(139, 0, 0, 0.4);
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05) rotate(1deg);
    }

    100% {
        transform: scale(1) rotate(-1deg);
    }
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

@keyframes glow {
    0% {
        box-shadow: 0 0 10px rgba(139, 0, 0, 0.2), 0 0 20px rgba(139, 0, 0, 0.2);
    }

    50% {
        box-shadow: 0 0 20px rgba(139, 0, 0, 0.6), 0 0 30px rgba(139, 0, 0, 0.5);
    }

    100% {
        box-shadow: 0 0 10px rgba(139, 0, 0, 0.2), 0 0 20px rgba(139, 0, 0, 0.2);
    }
}

@-webkit-keyframes fadeInUp {
    0% {
        opacity: 0;
        -webkit-transform: translateY(20px);
        transform: translateY(20px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateY(0);
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    0% {
        opacity: 0;
        -webkit-transform: translateY(20px);
        -ms-transform: translateY(20px);
        transform: translateY(20px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateY(0);
        -ms-transform: translateY(0);
        transform: translateY(0);
    }
}

@-webkit-keyframes fadeInRight {
    0% {
        opacity: 0;
        -webkit-transform: translateX(20px);
        transform: translateX(20px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateX(0);
        transform: translateX(0);
    }
}

@keyframes fadeInRight {
    0% {
        opacity: 0;
        -webkit-transform: translateX(40px);
        -ms-transform: translateX(40px);
        transform: translateX(40px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateX(0);
        -ms-transform: translateX(0);
        transform: translateX(0);
    }
}

@-webkit-keyframes pulse {
    0% {
        -webkit-transform: scale(1);
        transform: scale(1);
    }

    50% {
        -webkit-transform: scale(1.1);
        transform: scale(1.1);
    }

    100% {
        -webkit-transform: scale(1);
        transform: scale(1);
    }
}

@keyframes pulse {
    0% {
        -webkit-transform: scale(1);
        -ms-transform: scale(1);
        transform: scale(1);
    }

    50% {
        -webkit-transform: scale(1.1);
        -ms-transform: scale(1.1);
        transform: scale(1.1);
    }

    100% {
        -webkit-transform: scale(1);
        -ms-transform: scale(1);
        transform: scale(1);
    }
}

@-webkit-keyframes bounce {

    0%,
    20%,
    50%,
    80%,
    100% {
        -webkit-transform: translateY(0);
        transform: translateY(0);
    }

    40% {
        -webkit-transform: translateY(-30px);
        transform: translateY(-30px);
    }

    60% {
        -webkit-transform: translateY(-15px);
        transform: translateY(-15px);
    }
}

@keyframes bounce {

    0%,
    100%,
    20%,
    50%,
    80% {
        -webkit-transform: translateY(0);
        -ms-transform: translateY(0);
        transform: translateY(0);
    }

    40% {
        -webkit-transform: translateY(-30px);
        -ms-transform: translateY(-30px);
        transform: translateY(-30px);
    }

    60% {
        -webkit-transform: translateY(-15px);
        -ms-transform: translateY(-15px);
        transform: translateY(-15px);
    }
}

@-webkit-keyframes fadeInDown {
    0% {
        opacity: 0;
        -webkit-transform: translateY(-20px);
        transform: translateY(-20px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateY(0);
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    0% {
        opacity: 0;
        -webkit-transform: translateY(-20px);
        -ms-transform: translateY(-20px);
        transform: translateY(-20px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateY(0);
        -ms-transform: translateY(0);
        transform: translateY(0);
    }
}

@-webkit-keyframes fadeInLeft {
    0% {
        opacity: 0;
        -webkit-transform: translateX(-20px);
        transform: translateX(-20px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateX(0);
        transform: translateX(0);
    }
}

@keyframes fadeInLeft {
    0% {
        opacity: 0;
        -webkit-transform: translateX(-20px);
        -ms-transform: translateX(-20px);
        transform: translateX(-20px);
    }

    100% {
        opacity: 1;
        -webkit-transform: translateX(0);
        -ms-transform: translateX(0);
        transform: translateX(0);
    }
}

@-webkit-keyframes shake {

    0%,
    100% {
        -webkit-transform: translateX(0);
        transform: translateX(0);
    }

    10%,
    30%,
    50%,
    70%,
    90% {
        -webkit-transform: translateX(-10px);
        transform: translateX(-10px);
    }

    20%,
    40%,
    60%,
    80% {
        -webkit-transform: translateX(10px);
        transform: translateX(10px);
    }
}

@keyframes shake {

    0%,
    100% {
        -webkit-transform: translateX(0);
        -ms-transform: translateX(0);
        transform: translateX(0);
    }

    10%,
    30%,
    50%,
    70%,
    90% {
        -webkit-transform: translateX(-10px);
        -ms-transform: translateX(-10px);
        transform: translateX(-10px);
    }

    20%,
    40%,
    60%,
    80% {
        -webkit-transform: translateX(10px);
        -ms-transform: translateX(10px);
        transform: translateX(10px);
    }
}

@-webkit-keyframes snowflakes-fall {
    0% {
        top: -10%;
    }

    100% {
        top: 100%;
    }
}

@-webkit-keyframes snowflakes-shake {

    0%,
    100% {
        -webkit-transform: translateX(0);
        transform: translateX(0);
    }

    50% {
        -webkit-transform: translateX(80px);
        transform: translateX(80px);
    }
}

@keyframes snowflakes-fall {
    0% {
        top: -10%;
    }

    100% {
        top: 100%;
    }
}

@keyframes snowflakes-shake {

    0%,
    100% {
        transform: translateX(0);
    }

    50% {
        transform: translateX(80px);
    }
}

.snowflake {
    color: #fff;
    font-size: 1em;
    font-family: Arial, sans-serif;
    text-shadow: 0 0 5px #000;
    position: fixed;
    top: -10%;
    z-index: 9999;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    cursor: default;
    -webkit-animation-name: snowflakes-fall, snowflakes-shake;
    -webkit-animation-duration: 10s, 3s;
    -webkit-animation-timing-function: linear, ease-in-out;
    -webkit-animation-iteration-count: infinite, infinite;
    -webkit-animation-play-state: running, running;
    animation-name: snowflakes-fall, snowflakes-shake;
    animation-duration: 10s, 3s;
    animation-timing-function: linear, ease-in-out;
    animation-iteration-count: infinite, infinite;
    animation-play-state: running, running;
}

.snowflake:nth-of-type(0) {
    left: 1%;
    -webkit-animation-delay: 0s, 0s;
    animation-delay: 0s, 0s;
}

.snowflake:nth-of-type(1) {
    left: 10%;
    -webkit-animation-delay: 1s, 1s;
    animation-delay: 1s, 1s;
}

.snowflake:nth-of-type(2) {
    left: 20%;
    -webkit-animation-delay: 6s, 0.5s;
    animation-delay: 6s, 0.5s;
}

.snowflake:nth-of-type(3) {
    left: 30%;
    -webkit-animation-delay: 4s, 2s;
    animation-delay: 4s, 2s;
}

.snowflake:nth-of-type(4) {
    left: 40%;
    -webkit-animation-delay: 2s, 2s;
    animation-delay: 2s, 2s;
}

.snowflake:nth-of-type(5) {
    left: 50%;
    -webkit-animation-delay: 8s, 3s;
    animation-delay: 8s, 3s;
}

.snowflake:nth-of-type(6) {
    left: 60%;
    -webkit-animation-delay: 6s, 2s;
    animation-delay: 6s, 2s;
}

.snowflake:nth-of-type(7) {
    left: 70%;
    -webkit-animation-delay: 2.5s, 1s;
    animation-delay: 2.5s, 1s;
}

.snowflake:nth-of-type(8) {
    left: 80%;
    -webkit-animation-delay: 1s, 0s;
    animation-delay: 1s, 0s;
}

.snowflake:nth-of-type(9) {
    left: 90%;
    -webkit-animation-delay: 3s, 1.5s;
    animation-delay: 3s, 1.5s;
}

.snowflake:nth-of-type(10) {
    left: 25%;
    -webkit-animation-delay: 2s, 0s;
    animation-delay: 2s, 0s;
}

.snowflake:nth-of-type(11) {
    left: 65%;
    -webkit-animation-delay: 4s, 2.5s;
    animation-delay: 4s, 2.5s;
}