.nav-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    z-index: 9999;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s ease;
}

    .nav-progress.loading {
        opacity: 1;
    }

.nav-progress__bar {
    height: 100%;
    width: 0;
    background: var(--mud-palette-primary, #1976d2);
    box-shadow: 0 0 8px var(--mud-palette-primary, #1976d2), 0 0 4px var(--mud-palette-primary, #1976d2);
    border-radius: 0 2px 2px 0;
}

/* start — szybko do ~90%, potem zwalnia */
.nav-progress.loading .nav-progress__bar {
    animation: nav-progress-grow 8s cubic-bezier(0.2, 0.8, 0.3, 1) forwards;
}

/* finish — dobij do 100% i zniknij */
.nav-progress.finishing .nav-progress__bar {
    animation: none;
    width: 100%;
    transition: width 0.25s ease-out;
}

.nav-progress.finishing {
    opacity: 0;
    transition: opacity 0.3s 0.25s ease;
}

@keyframes nav-progress-grow {
    0% {
        width: 0;
    }

    10% {
        width: 30%;
    }

    30% {
        width: 60%;
    }

    60% {
        width: 80%;
    }

    100% {
        width: 92%;
    }
}