@font-face {
    font-family: 'ByteBounce';
    src: url('./fonts/ByteBounce.ttf') format('truetype');
}
body {
    margin: 0;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #0a0a0a;
    font-family: 'ByteBounce', monospace;
    flex-direction: column;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.back-btn {
    position: absolute;
    top: 20px;
    left: 20px;
    background: rgba(0,0,0,0.5);
    color: #fff;
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 1rem;
    text-decoration: none;
    transition: background 0.3s, transform 0.2s;
    z-index: 10;
}
.back-btn:hover {
    background: rgba(255,255,255,0.2);
    transform: scale(1.05);
}
.spotlight {
    position: absolute;
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, rgba(255,255,255,0.18) 0%, rgba(0,0,0,0) 70%);
    border-radius: 50%;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 0;
    pointer-events: none;
}
.mask-container {
    position: relative;
    z-index: 1;
}
.mask-container img {
    width: 200px;
    max-width: 50vw;
    display: block;
    position: relative;
    z-index: 1;
    filter: drop-shadow(0 0 2px rgba(255,255,255,0.1))
            drop-shadow(0 0 4px rgba(255,255,255,0.05));
}
.mask-text {
    margin-top: 2rem;
    font-size: 2rem;
    cursor: pointer;
    display: inline-block;
    letter-spacing: 0.1em;
    position: relative;
    color: #fff;
    text-decoration: underline;
    text-decoration-thickness: 2px;
}
.mask-text .numbers {
    display: inline-block;
    transition: opacity 0.3s ease;
}
.mask-text .hover-text {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    text-decoration: underline;
    text-decoration-thickness: 2px;
    color: #fff;
    opacity: 0;
    transition: opacity 0.3s ease;
}
.mask-text:hover .numbers,
.mask-text:active .numbers {
    opacity: 0;
}
.mask-text:hover .hover-text,
.mask-text:active .hover-text {
    opacity: 1;
}
.mask-text .numbers::after,
.mask-text .hover-text::after {
    content: "_";
    margin-left: 0.1em;
    animation: blink 1s infinite;
}
@keyframes blink {
    0%, 50%, 100% { opacity: 1; }
    25%, 75% { opacity: 0; }
}
.mask-text .numbers,
.mask-text .hover-text {
    text-shadow: 0 0 1px #fff;
}
@media (max-width: 600px) {
    .mask-container img { width: 150px; }
    .mask-text { font-size: 1.5rem; }
    .back-btn { font-size: 0.9rem; padding: 6px 10px; }
}