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

.background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1
}

.background img {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0;
    transition: opacity 2s ease-in-out
}

.background img.active {
    opacity: 1
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center
}

.btn {
    background-color: #3b3c3b;
    color: #fff;
    padding: 1em 2em;
    font-size: 1.2em;
    text-decoration: none;
    border-radius: 8px;
    transition: background-color .3s ease, color .3s ease
}

.btn:hover {
    background-color: #fed223;
    color: #000
}

.counter {
    position: fixed;
    bottom: 15px;
    left: 50%;
    transform: translateX(-50%);
    color: #fff;
    font-size: .95em;
    background-color: rgba(0, 0, 0, .4);
    padding: 4px 10px;
    border-radius: 12px;
    z-index: 10;
    user-select: none
}

.countdown {
    position: fixed;
    bottom: 50px;
    left: 50%;
    transform: translateX(-50%);
    color: #fff;
    font-size: 1.1em;
    background-color: rgba(0, 0, 0, .4);
    padding: 6px 12px;
    border-radius: 12px;
    z-index: 10;
    user-select: none
}

.modal {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.modal-content {
    background: #fff;
    padding: 2em;
    border-radius: 10px;
    max-width: 90%;
    width: 400px;
    position: relative;
    text-align: center;
    font-family: Arial, sans-serif;
    box-shadow: 0 0 20px rgba(0,0,0,0.3);
}

.modal-content h2 {
    margin-top: 0;
    font-size: 1.4em;
}

.close-button {
    position: absolute;
    top: 10px; right: 15px;
    font-size: 24px;
    cursor: pointer;
}

.modal-btn {
    display: block;
    background-color: #3b3c3b;
    color: white;
    font-size: 1.2em;
    font-weight: bold;
    padding: 12px 20px;
    border-radius: 6px;
    text-decoration: none;
    text-align: center;
    margin: 20px auto;
    transition: background-color 0.3s ease;
}

.modal-btn:hover {
    background-color: #fed223;
    color: #000;
}