html,
body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: 'Ubuntu', sans-serif;
    color: white;
    overflow: hidden;
}

.background-image {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('danang.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    z-index: -2;
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0) 50%, rgba(0, 0, 0, 0.7) 100%);
    z-index: -1;
}

.content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    text-shadow: 1px 1px 10px rgba(0, 0, 0, 0.7);
}

.content h1 {
    font-size: 4rem;
    margin: 0;
    letter-spacing: 5px;
    line-height: 3.8rem;
    color: white;
    text-shadow: 2px 2px 2px black;
    font-weight: 800;
}

.subtitle {
    font-size: 1.5rem;
    margin-top: 10px;
    font-weight: 800;
    letter-spacing: 3px;
    color: white;
    text-shadow: 2px 2px 2px black;
    line-height: 1.2rem;
    letter-spacing: 9px;
}