/* ================================================================
   CRIS LANDING — BACK TO TOP (scroll-progress ring + gradient core)
   Rules: no inline styles, no !important, no media queries.
          State: data-visible="true|false", data-progress="0..20"
          (5% steps); JS only updates those values.
          Responsive value set per range in responsive.css under
          ".plx-back-top": --btt-bottom
   ================================================================ */

.plx-back-top {

  align-items: center;
  bottom: var(--sp-185);
  cursor: pointer;
  display: flex;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  position: fixed;
  right: var(--pos-30);
  transform: translateY(14px) scale(.88);
  transition: opacity var(--t-medium) cubic-bezier(0.4,0,0.2,1), transform var(--t-medium) cubic-bezier(0.4,0,0.2,1);
  z-index: var(--z-9500);
}
.plx-back-top[data-visible="true"] {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0) scale(1);
}

/* Ring (rotated so the arc starts at the top) */
.plx-btt-ring {
  height: var(--size-56);
  position: absolute;
  transform: rotate(-90deg);
  width: var(--size-56);
}
.plx-btt-track { fill: none; stroke: var(--border-md); stroke-width: 2.5; }
.plx-btt-fill {
  fill: none;
  stroke: var(--lime);
  stroke-dasharray: 157.08;
  stroke-dashoffset: calc(157.08 * (1 - var(--btt-p, 0)));
  stroke-linecap: round;
  stroke-width: 2.5;
  transition: stroke-dashoffset var(--t-fast) linear;
}

/* Progress steps (--btt-p = share of the ring that is filled) */
.plx-back-top[data-progress="0"]  { --btt-p: 0; }
.plx-back-top[data-progress="1"]  { --btt-p: .05; }
.plx-back-top[data-progress="2"]  { --btt-p: .1; }
.plx-back-top[data-progress="3"]  { --btt-p: .15; }
.plx-back-top[data-progress="4"]  { --btt-p: .2; }
.plx-back-top[data-progress="5"]  { --btt-p: .25; }
.plx-back-top[data-progress="6"]  { --btt-p: .3; }
.plx-back-top[data-progress="7"]  { --btt-p: .35; }
.plx-back-top[data-progress="8"]  { --btt-p: .4; }
.plx-back-top[data-progress="9"]  { --btt-p: .45; }
.plx-back-top[data-progress="10"] { --btt-p: .5; }
.plx-back-top[data-progress="11"] { --btt-p: .55; }
.plx-back-top[data-progress="12"] { --btt-p: .6; }
.plx-back-top[data-progress="13"] { --btt-p: .65; }
.plx-back-top[data-progress="14"] { --btt-p: .7; }
.plx-back-top[data-progress="15"] { --btt-p: .75; }
.plx-back-top[data-progress="16"] { --btt-p: .8; }
.plx-back-top[data-progress="17"] { --btt-p: .85; }
.plx-back-top[data-progress="18"] { --btt-p: .9; }
.plx-back-top[data-progress="19"] { --btt-p: .95; }
.plx-back-top[data-progress="20"] { --btt-p: 1; }

/* Gradient core */
.plx-btt-inner {
  align-items: center;
  background: linear-gradient(135deg,var(--lime) 0%,var(--green) 55%,var(--green) 100%);
  border-radius: 50%;
  box-shadow: 0 4px 20px var(--black-a50);
  color: var(--bg);
  display: flex;
  height: var(--size-42);
  justify-content: center;
  position: relative;
  transition: transform var(--t-default) cubic-bezier(0.4,0,0.2,1), filter var(--t-default), box-shadow var(--t-default);
  width: var(--size-42);
  z-index: var(--z-1);
}
.plx-back-top:hover .plx-btt-inner { box-shadow: 0 0 30px var(--green-a85), 0 4px 20px var(--black-a50); filter: brightness(1.1); }
.plx-back-top:active .plx-btt-inner { transform: scale(.94); }
.plx-btt-arrow { display: block; height: var(--size-18); width: var(--size-18); }
.plx-back-top:focus-visible .plx-btt-inner { outline: 2px solid var(--lime); outline-offset: 4px; }