/* ===============================
         Stacked Card (FLOW SAFE)
=============================== */

.stacked-card {
  position: relative;
  isolation: isolate;
  display: block;

  /* IoC variables */
  --card-size: 14px;
  --card-offset: -8px;
  --card-radius: 20px;
  --card-bg: #abd45b;
  --card-shadow: 0 8px 16px rgba(14, 76, 55, 0.12);
  --front-push-x: 0px;
  --front-push-y: 0px;

  /* ⭐ 關鍵：為向上突出預留空間 */
  --band-overhang: clamp(0px, calc(-1 * var(--card-offset)), 999px);
  --front-overhang: clamp(0px, calc(-1 * var(--front-push-y)), 999px);
  margin-top: calc(var(--band-overhang) + var(--front-overhang));
}

/* band layer */
.stacked-card::before {
  content: "";
  position: absolute;
  z-index: 0;
  background: var(--card-bg);
  box-shadow: var(--card-shadow);
  pointer-events: none;
}

/* top band */
.stacked-card.is-top::before {
  left: 0;
  right: 0;
  top: var(--card-offset);
  height: var(--card-size);
  border-radius: var(--card-radius) var(--card-radius) 0 0;
}

/* front card */
.stacked-card__front {
  position: relative;
  z-index: 1;
  transform: translate(var(--front-push-x), var(--front-push-y));
  background: #fff;
  border-radius: var(--card-radius);
  box-shadow: 0 12px 24px rgba(14, 76, 55, 0.12);
}

.stack-overlap > .stacked-card + .stacked-card {
  margin-top: var(--overlap, -20px);
}
/* Floating icon box */
.icon-float-box {
  position: relative;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100px;
  height: 100px;
  background: #ebffe8;
  border-radius: 12px;
  box-shadow:
    -8px 8px 0 #008d79,
    0 6px 14px rgba(14, 76, 55, 0.18);
  transform: translate(0, 5px);
  flex-shrink: 0;
}

.tabs-shell {
  background: #eef4f2;
  border-radius: 20px;
  padding: 10px;
  box-shadow: 0 10px 18px rgba(14, 76, 55, 0.1);
  justify-self: center;
  gap: 10px;
  margin: 0 18px 0 10px;
}

.tab-btn {
  border: 0;
  cursor: pointer;
  padding: 22px 34px;
  border-radius: 20px;
  background: transparent;
  color: #111;
  font-weight: 800;
  font-size: 22px;
  width: 280px;
  height: -webkit-fill-available;
}
.tab-btn.is-active {
  background: #056154;
  color: #fff;
}

@media (max-width: 1340px) {
  .powerup.hstack {
    flex-direction: column;
  }
}

@media (max-width: 768px) {
  .icon-float-box {
    align-self: center;
  }
}

@media (max-width: 1024px) {
  .tabs-shell {
    gap: 0px;
    width: 95%;
  }

  .tab-btn {
    width: 100%;
    padding: 16px 5px;
    font-size: 20px;
  }
}