/* Canvas plein écran */
#btpmat-snow-canvas {
    image-rendering: auto;
}

/* Faux chapeau de neige en haut des éléments clés */
.header-container,
.footer-container,
.has-snow-cap {
    position: relative;
}

.header-container::before,
.footer-container::before,
.has-snow-cap::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: -4px;
    height: 10px;
    background: radial-gradient(circle at 10% 0, #fff 0, rgba(255,255,255,0) 70%),
                radial-gradient(circle at 30% 0, #fff 0, rgba(255,255,255,0) 70%),
                radial-gradient(circle at 50% 0, #fff 0, rgba(255,255,255,0) 70%),
                radial-gradient(circle at 70% 0, #fff 0, rgba(255,255,255,0) 70%),
                radial-gradient(circle at 90% 0, #fff 0, rgba(255,255,255,0) 70%);
    pointer-events: none;
    opacity: 0;
    transition: opacity 1s ease-in;
}

/* On "fait apparaître" la neige posée après quelques secondes via JS */
body.btpmat-snow-on .header-container::before,
body.btpmat-snow-on .footer-container::before,
body.btpmat-snow-on .has-snow-cap::before {
    opacity: 1;
}