/* Animation Definitions */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slideUp {
  from {
    transform: translateY(20px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

@keyframes slideDown {
  from {
    transform: translateY(-20px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

@keyframes shimmer {
  0% {
    background-position: -1000px 0;
  }
  100% {
    background-position: 1000px 0;
  }
}

@keyframes bounce {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* Applied Animations */
.card {
  animation: fadeIn var(--transition-normal);
}

.input-section .card:first-child {
  animation: slideDown var(--transition-normal);
}

.input-section .card:last-child {
  animation: slideDown var(--transition-normal);
  animation-delay: 100ms;
}

.results-section .card {
  animation: slideUp var(--transition-slow);
}

.stat-item {
  transition: transform var(--transition-fast);
}

.stat-item:hover {
  transform: translateY(-3px);
}

.primary-btn:active {
  transform: scale(0.98);
}

.tab-btn {
  position: relative;
}

.tab-btn::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-primary-600);
  transform: scaleX(0);
  transition: transform var(--transition-normal);
}

.tab-btn.active::after {
  transform: scaleX(1);
}

.tab-content {
  animation: fadeIn var(--transition-normal);
}

/* Loading animation for calculate button */
.loading-btn {
  position: relative;
  overflow: hidden;
  pointer-events: none;
}

.loading-btn::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0) 0%,
    rgba(255, 255, 255, 0.2) 20%,
    rgba(255, 255, 255, 0.5) 60%,
    rgba(255, 255, 255, 0) 100%
  );
  animation: shimmer 2s infinite;
}

/* Results row appearance animation */
.appear-row {
  animation: fadeIn 300ms ease-out forwards;
}

/* Chart animations */
.chart-appear {
  opacity: 0;
  transform: scale(0.95);
  transition: opacity 500ms ease-out, transform 500ms ease-out;
}

.chart-appear.visible {
  opacity: 1;
  transform: scale(1);
}

/* Grade emoji animation */
.grade-emoji {
  display: inline-block;
  font-size: 2rem;
  margin-right: 0.5rem;
  animation: bounce 2s ease-in-out infinite;
}

/* Focus states */
button:focus, 
input:focus, 
select:focus, 
textarea:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.3);
}

/* Hover effects for interactive elements */
.grades-table tbody tr {
  transition: background-color var(--transition-fast);
}

.boundary-row {
  transition: transform var(--transition-fast), background-color var(--transition-fast);
}

.boundary-row:hover {
  background-color: var(--color-gray-100);
  transform: translateX(4px);
  border-radius: var(--radius-sm);
}

/* Feedback animations */
.success-flash {
  animation: successFlash 1.5s ease-out;
}

@keyframes successFlash {
  0%, 100% {
    background-color: transparent;
  }
  50% {
    background-color: rgba(34, 197, 94, 0.1);
  }
}