.stroop-card {
  background: var(--glass);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  box-shadow: 0 0 60px 2px color-mix(in srgb, var(--accent) 11%, transparent);
  padding: 50px 20px;
  text-align: center;
  margin-bottom: 16px;
  min-height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, border-color 0.15s;
  position: relative;
  overflow: hidden;
}

.stroop-timer {
  position: absolute;
  top: 0;
  left: 0;
  height: 4px;
  background: var(--accent);
  width: 100%;
  transition: width linear;
}

.stroop-timer.warn { background: var(--warn); }
.stroop-timer.danger { background: var(--bad); }

.stroop-card.good {
  background: rgba(74, 222, 128, 0.15);
  border-color: var(--good);
}

.stroop-card.bad {
  background: rgba(228, 74, 74, 0.15);
  border-color: var(--bad);
}

.stroop-word {
  font-size: 60px;
  font-weight: 900;
  letter-spacing: 4px;
  text-shadow: 0 0 30px currentColor;
}

.color-choices {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.color-btn {
  border: none;
  border-radius: 14px;
  padding: 22px;
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  color: #fff;
  transition: transform 0.1s, opacity 0.1s;
}

.color-btn:active { transform: scale(0.97); }
.color-btn:disabled { opacity: 0.5; }