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

body, html {
    height: 100%;
    font-family: Arial, sans-serif;
    color: #fff;
    background-color: #001f3f;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
}

/* Background Container */
.background {
    position: relative;
    width: 100%;
    height: 100vh;
    background: url('PC/BR_2.jpg') no-repeat center center;
    background-size: cover;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    overflow: hidden;
    animation: fadeIn 1s ease-in-out;
}

/* Fade-in Animation */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* 2 ảnh trang trí 2 bên */
.side-image {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    max-width: 100%;
    height: auto;
    z-index: 1;
    animation: float 3s ease-in-out infinite;
}

.side-image.left {
    left: 0;
    animation-delay: 0s;
}

.side-image.right {
    right: 0;
    animation-delay: 1.5s;
}

/* Floating Animation */
@keyframes float {
    0% { transform: translateY(-50%) translateX(0px); }
    50% { transform: translateY(-48%) translateX(10px); }
    100% { transform: translateY(-50%) translateX(0px); }
}

/* Overlay (optional) */
.overlay {
    background: rgba(0, 0, 0, 0.5);
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

/* Logo */
header {
    margin-top: 20px;
    animation: fadeIn 1.5s ease-in-out;
}

header .logo {
    max-width: 200px;
    height: auto;
    margin-bottom: 20px;
}

/* Promo Banner */
.promo-banner {
    text-align: center;
    margin-top: 160px;
    z-index: 2;
    animation: slideUp 1s ease-out;
}

.promo-banner img {
    max-width: 100%;
    height: auto;
    transition: transform 0.3s;
}

.promo-banner img:hover {
    transform: scale(1.05);
}

/* CTA Buttons */
.cta-buttons {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 260px;
    z-index: 2;
    animation: slideUp 1.2s ease-out;
}

.cta-buttons img {
    max-width: 100%;
    margin: 10px 0;
    cursor: pointer;
    transition: transform 0.3s;
}

.cta-buttons img:hover {
    transform: scale(1.05);
}

.cta-btn {
    background: #FF9900;
    color: #fff;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
    transition: background 0.3s, transform 0.3s;
    margin-top: 20px;
}

.cta-btn:hover {
    background: #FFB84D;
    transform: scale(1.05);
}

/* Slide-up Animation */
@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Mobile background and extra animation */
@media (max-width: 768px) {
    .background {
        background: url('MOBILE/BR_2.jpg') no-repeat center center;
        background-size: cover;
    }

    /* Ẩn side images trên mobile */
    .side-image {
        display: none;
    }

    .promo-banner {
        margin-top: 120px;
    }

    .cta-buttons {
        margin-top: 10px;
        display: flex;
        flex-direction: column;
        align-items: center;
        text-align: center;
        animation: mobileSlideUp 1.2s ease-out;
    }

    .cta-buttons img {
        max-width: 80%;
        height: auto;
        margin: 10px 0;
        animation: mobileFloat 3s ease-in-out infinite;
    }

    .cta-btn {
        font-size: 16px;
        padding: 12px 24px;
        animation: mobileSlideUp 1.2s ease-out, mobileFloat 3s ease-in-out infinite;
    }
}
/* Nhấp nháy và zoom-in-zoom-out cho nút đăng ký */
.promo-banner a img {
    animation: blinkZoom 1.5s infinite;
}

/* Animation cho nút đăng ký */
@keyframes blinkZoom {
    0% {
        transform: scale(1);
        opacity: 1;
    }
    25% {
        transform: scale(1.1);
        opacity: 0.8;
    }
    50% {
        transform: scale(1);
        opacity: 1;
    }
    75% {
        transform: scale(1.1);
        opacity: 0.8;
    }
    100% {
        transform: scale(1);
        opacity: 1;
    }
}

/* Mobile Slide Up Animation */
@keyframes mobileSlideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Mobile Float Animation */
@keyframes mobileFloat {
    0% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-5px);
    }
    100% {
        transform: translateY(0px);
    }
}