/* ==========================================================================
   062 — Checkbox Burst
   Case à cocher CSS-only : au check, la boîte rebondit (squash & stretch),
   le check se dessine au stroke-dashoffset et 8 étincelles + un anneau
   explosent autour. Basé sur un input caché :checked.
   ========================================================================== */

.checkbox-burst {
  --cb-size: 26px;
  --cb-accent: var(--ml-accent, #7c8cff);
  --cb-spark: var(--ml-accent-2, #2dd4bf);

  display: inline-flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  color: var(--ml-fg, #e8eaf2);
  font-size: 0.95rem;
  user-select: none;
  -webkit-user-select: none;
}

/* input masqué mais focusable (accessibilité clavier) */
.checkbox-burst__input {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  clip-path: inset(50%);
  overflow: hidden;
  white-space: nowrap;
}

/* --- Boîte ------------------------------------------------------------------ */

.checkbox-burst__box {
  position: relative;
  flex: none;
  width: var(--cb-size);
  height: var(--cb-size);
  border-radius: 8px;
  border: 2px solid color-mix(in srgb, var(--ml-muted, #8b91a3) 60%, transparent);
  background-color: transparent;
  transition:
    border-color 0.25s ease,
    background-color 0.25s ease,
    transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.checkbox-burst:hover .checkbox-burst__box {
  border-color: var(--cb-accent);
  transform: scale(1.06);
}

.checkbox-burst__input:focus-visible + .checkbox-burst__box {
  outline: 2px solid var(--cb-accent);
  outline-offset: 3px;
}

.checkbox-burst__input:checked + .checkbox-burst__box {
  border-color: var(--cb-accent);
  background-color: var(--cb-accent);
  background-image: linear-gradient(
    135deg,
    var(--cb-accent),
    color-mix(in srgb, var(--cb-accent) 55%, var(--cb-spark))
  );
  animation: checkbox-burst-pop 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* squash & stretch : creuse, surgit, se pose */
@keyframes checkbox-burst-pop {
  0%   { transform: scale(1); }
  35%  { transform: scale(0.82, 0.78); }
  65%  { transform: scale(1.14, 1.18); }
  100% { transform: scale(1); }
}

/* --- Check dessiné au stroke --------------------------------------------------- */

.checkbox-burst__svg {
  position: absolute;
  inset: 2px;
  display: block;
  width: calc(100% - 4px);
  height: calc(100% - 4px);
  pointer-events: none;
}

.checkbox-burst__check {
  fill: none;
  stroke: var(--ml-bg, #0d1017);
  stroke-width: 3.2;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 1; /* pathLength="1" */
  stroke-dashoffset: 1;
  transition: stroke-dashoffset 0.16s ease; /* décoche : le trait se rétracte vite */
}

.checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__check {
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 0.3s cubic-bezier(0.65, 0, 0.35, 1) 0.14s;
}

/* --- Anneau d'onde --------------------------------------------------------------- */

.checkbox-burst__ring {
  position: absolute;
  inset: -5px;
  border-radius: 50%;
  border: 2px solid var(--cb-spark);
  opacity: 0;
  transform: scale(0.4);
  pointer-events: none;
}

.checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__ring {
  animation: checkbox-burst-ring 0.55s cubic-bezier(0.22, 1, 0.36, 1) 0.08s;
}

@keyframes checkbox-burst-ring {
  0%   { opacity: 0.75; transform: scale(0.4); }
  100% { opacity: 0;    transform: scale(1.9); }
}

/* --- Étincelles -------------------------------------------------------------------- */

.checkbox-burst__spark {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 5px;
  height: 5px;
  margin: -2.5px 0 0 -2.5px;
  border-radius: 50%;
  background: var(--cb-accent);
  opacity: 0;
  pointer-events: none;
}

/* étincelles paires : plus petites, teintées accent-2, en léger différé */
.checkbox-burst__spark--2,
.checkbox-burst__spark--4,
.checkbox-burst__spark--6,
.checkbox-burst__spark--8 {
  width: 4px;
  height: 4px;
  margin: -2px 0 0 -2px;
  background: var(--cb-spark);
}

.checkbox-burst__spark--1 { --cb-a: 0deg;   --cb-d: 27px; }
.checkbox-burst__spark--2 { --cb-a: 45deg;  --cb-d: 21px; }
.checkbox-burst__spark--3 { --cb-a: 90deg;  --cb-d: 26px; }
.checkbox-burst__spark--4 { --cb-a: 135deg; --cb-d: 22px; }
.checkbox-burst__spark--5 { --cb-a: 180deg; --cb-d: 27px; }
.checkbox-burst__spark--6 { --cb-a: 225deg; --cb-d: 21px; }
.checkbox-burst__spark--7 { --cb-a: 270deg; --cb-d: 26px; }
.checkbox-burst__spark--8 { --cb-a: 315deg; --cb-d: 22px; }

.checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__spark {
  animation: checkbox-burst-spark 0.6s cubic-bezier(0.16, 0.84, 0.32, 1) 0.12s;
}

.checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__spark--2,
.checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__spark--4,
.checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__spark--6,
.checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__spark--8 {
  animation-duration: 0.5s;
  animation-delay: 0.18s;
}

@keyframes checkbox-burst-spark {
  0%   { opacity: 0; transform: rotate(var(--cb-a, 0deg)) translateY(-7px) scale(0.4); }
  20%  { opacity: 1; }
  70%  { opacity: 1; transform: rotate(var(--cb-a, 0deg)) translateY(calc(var(--cb-d, 24px) * -0.85)) scale(1); }
  100% { opacity: 0; transform: rotate(var(--cb-a, 0deg)) translateY(calc(var(--cb-d, 24px) * -1)) scale(0.2); }
}

/* --- Libellé + wrapper de démo (galerie) --------------------------------------------- */

.checkbox-burst__text {
  line-height: 1.3;
}

.checkbox-burst-demo {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 18px;
}

/* --- Reduced motion ------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  .checkbox-burst__input:checked + .checkbox-burst__box,
  .checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__spark,
  .checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__ring {
    animation: none;
  }

  .checkbox-burst__box {
    transition: border-color 0.01s ease, background-color 0.01s ease;
  }

  .checkbox-burst:hover .checkbox-burst__box {
    transform: none;
  }

  .checkbox-burst__check,
  .checkbox-burst__input:checked + .checkbox-burst__box .checkbox-burst__check {
    transition-duration: 0.01s;
    transition-delay: 0s;
  }
}