/* ============================================================
   Frostfeed — "How it works" vertical scroll timeline
   The line draws itself as you scroll; each node lights when the
   fill reaches it. Calm, frosted, accessible.
   ============================================================ */

.tl {
  position: relative;
  padding-left: 58px;
  max-width: 60ch;
}

/* the vertical line: faint track + accent progress fill */
.tl__line {
  position: absolute;
  left: 17px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--divider);
  border-radius: 2px;
  overflow: hidden;
}
.tl__fill {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 0;
  background: var(--accent);
  border-radius: 2px;
}

.tl__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: clamp(56px, 9vh, 108px);
}
.tl__step { position: relative; }

/* node sits on the line */
.tl__node {
  position: absolute;
  left: -50px;
  top: 6px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--divider);
  box-shadow: 0 0 0 0 transparent;
  transition:
    background 0.5s var(--ease),
    border-color 0.5s var(--ease),
    box-shadow 0.5s var(--ease);
}

/* content — dimmed until activated */
.tl__num {
  font-family: var(--font-head);
  font-size: 1.5rem;
  color: var(--accent);
  font-feature-settings: "lnum";
  margin-bottom: var(--space-1);
}
.tl__title { font-size: 1.3rem; margin-bottom: 6px; }
.tl__desc { color: var(--ink-2); font-size: 1rem; line-height: 1.55; text-wrap: pretty; max-width: 46ch; }

.tl__num, .tl__title, .tl__desc {
  opacity: 0.25;
  transform: translateY(16px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
.tl__title { transition-delay: 60ms; }
.tl__desc  { transition-delay: 120ms; }

/* activated state */
.tl__step.is-active .tl__node {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 0 6px color-mix(in srgb, var(--accent) 16%, transparent);
}
.tl__step.is-active .tl__num,
.tl__step.is-active .tl__title,
.tl__step.is-active .tl__desc {
  opacity: 1;
  transform: none;
}

/* reduced motion: fully drawn, lit, no transforms */
@media (prefers-reduced-motion: reduce) {
  .tl__node, .tl__num, .tl__title, .tl__desc { transition: none !important; }
  .tl__num, .tl__title, .tl__desc { opacity: 1 !important; transform: none !important; }
  .tl__fill { height: 100% !important; }
  .tl__node {
    background: var(--accent); border-color: var(--accent);
    box-shadow: 0 0 0 6px color-mix(in srgb, var(--accent) 16%, transparent);
  }
}