body {
    background: linear-gradient(120deg, #232526 0%, #414345 100%);
    min-height: 100vh;
}
.screen-card {
    transition: transform 0.2s, box-shadow 0.2s;
}
.screen-card:hover {
    transform: scale(1.03);
    box-shadow: 0 0 20px #00c6ff33;
}
.loader {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #00c6ff;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    display: block;
    margin: auto;
}
@keyframes spin {
    0% { transform: rotate(0deg);}
    100% { transform: rotate(360deg);}
}
.btn-anim {
    transition: background 0.2s, transform 0.2s;
}
.btn-anim:active {
    transform: scale(0.97);
    background: #00c6ff;
}