/* =========================================================
   SECTION SCROLLER — mała strzałka na dole/na górze ekranu,
   która płynnie przeskakuje między sekcjami strony głównej.
   Subtelna, dopasowana do reszty serwisu (ciemny glass + czerwień).
   ========================================================= */
.kf-scroller {
    position: fixed;
    left: 50%;
    bottom: 22px;
    transform: translateX(-50%);
    z-index: 900;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    pointer-events: none; /* tylko przyciski łapią klik */
}

.kf-scroller__btn {
    pointer-events: auto;
    width: 42px;
    height: 42px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: rgba(15, 15, 15, 0.7);
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.14);
    color: #fff;
    cursor: pointer;
    font-size: 0.95rem;
    line-height: 1;
    opacity: 0.82;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.45);
    transition: transform 0.28s cubic-bezier(0.2, 0.8, 0.2, 1),
                background 0.25s ease, border-color 0.25s ease,
                opacity 0.35s ease, visibility 0.35s ease;
}

.kf-scroller__btn:hover {
    opacity: 1;
    background: rgba(230, 0, 0, 0.92);
    border-color: rgba(230, 0, 0, 0.9);
    transform: translateY(-3px);
    box-shadow: 0 10px 26px rgba(230, 0, 0, 0.4);
}

.kf-scroller__btn:active {
    transform: translateY(-1px) scale(0.95);
}

.kf-scroller__btn:focus-visible {
    outline: 2px solid #E60000;
    outline-offset: 3px;
}

/* Przycisk "do góry" — mniejszy, pojawia się dopiero po przewinięciu */
.kf-scroller__btn--up {
    width: 35px;
    height: 35px;
    font-size: 0.8rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
}
.kf-scroller.show-up .kf-scroller__btn--up {
    opacity: 0.78;
    visibility: visible;
    transform: translateY(0);
}

/* Na samym dole strony chowamy strzałkę w dół */
.kf-scroller.at-bottom .kf-scroller__btn--down {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(8px);
}

/* Delikatna podpowiedź — bardzo subtelne, powolne bujanie ikony w dół */
.kf-scroller__btn--down i {
    animation: kfBob 2.8s ease-in-out infinite;
}
.kf-scroller__btn--down:hover i {
    animation: none;
}
@keyframes kfBob {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(3px); }
}

@media (prefers-reduced-motion: reduce) {
    .kf-scroller__btn--down i { animation: none; }
    .kf-scroller__btn { transition: opacity 0.2s ease, visibility 0.2s ease; }
}

@media (max-width: 600px) {
    .kf-scroller { bottom: 16px; gap: 7px; }
    .kf-scroller__btn { width: 37px; height: 37px; font-size: 0.85rem; }
    .kf-scroller__btn--up { width: 32px; height: 32px; }
}