/* ==========================================================================
   Animation and Transition Styles
   ========================================================================== */

/* ==========================================================================
   Keyframe Animations
   ========================================================================== */

/* Grow and Skew Forward */
@keyframes grow_skew_forward {
  0% {
    transform: scale(1) skew(0deg);
  }
  100% {
    transform: scale(1.1) skew(-3deg);
  }
}

/* Fade Animations */
@keyframes fade_in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fade_out {
  from { opacity: 1; }
  to { opacity: 0; }
}

/* Slide Animations */
@keyframes slide_in_right {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@keyframes slide_in_left {
  from {
    transform: translateX(-100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@keyframes slide_in_up {
  from {
    transform: translateY(100%);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

/* Scale Animations */
@keyframes scale_in {
  from {
    transform: scale(0);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

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

/* Rotation Effects */
@keyframes rotate_360 {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes swing {
  20% { transform: rotate(15deg); }
  40% { transform: rotate(-10deg); }
  60% { transform: rotate(5deg); }
  80% { transform: rotate(-5deg); }
  100% { transform: rotate(0deg); }
}

/* ==========================================================================
   Hover Effects
   ========================================================================== */

/* Link Hover States */
.hover-underline {
  position: relative;
}

.hover-underline::after {
  content: '';
  position: absolute;
  width: 100%;
  height: 2px;
  bottom: -2px;
  left: 0;
  background-color: var(--color-primary);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.hover-underline:hover::after {
  transform: scaleX(1);
}

/* Button Interactions */
.btn-hover-grow {
  transition: transform 0.3s ease;
}

.btn-hover-grow:hover {
  transform: scale(1.05);
}

.btn-hover-slide {
  position: relative;
  overflow: hidden;
}

.btn-hover-slide::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.2);
  transition: left 0.3s ease;
}

.btn-hover-slide:hover::before {
  left: 100%;
}

/* Card Hover Animations */
.card-hover-lift {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card-hover-lift:hover {
  transform: translateY(-10px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

/* Image Hover Effects */
.img-hover-zoom {
  overflow: hidden;
}

.img-hover-zoom img {
  transition: transform 0.5s ease;
}

.img-hover-zoom:hover img {
  transform: scale(1.1);
}

/* Menu Item Transitions */
.menu-item-hover {
  transition: color 0.3s ease, padding-left 0.3s ease;
}

.menu-item-hover:hover {
  color: var(--color-primary);
  padding-left: var(--spacing-2);
}

/* ==========================================================================
   Transition Utilities
   ========================================================================== */

/* Common Transition Durations */
.transition-fast {
  transition-duration: 150ms;
}

.transition-normal {
  transition-duration: 300ms;
}

.transition-slow {
  transition-duration: 500ms;
}

/* Easing Functions */
.ease-linear {
  transition-timing-function: linear;
}

.ease-in {
  transition-timing-function: cubic-bezier(0.4, 0, 1, 1);
}

.ease-out {
  transition-timing-function: cubic-bezier(0, 0, 0.2, 1);
}

.ease-in-out {
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

/* Transform Utilities */
.transform-gpu {
  transform: translate3d(0, 0, 0);
  backface-visibility: hidden;
}

.transform-none {
  transform: none;
}

/* Opacity Transitions */
.opacity-transition {
  transition: opacity 0.3s ease;
}

.opacity-0 {
  opacity: 0;
}

.opacity-50 {
  opacity: 0.5;
}

.opacity-100 {
  opacity: 1;
}

/* State Transitions */
.state-transition {
  transition: all 0.3s ease;
}

.state-active {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.state-focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ==========================================================================
   Loading Animations
   ========================================================================== */

/* Spinner Animation */
.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--color-gray-200);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: rotate_360 1s linear infinite;
}

/* Skeleton Loading */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-gray-200) 25%,
    var(--color-gray-300) 37%,
    var(--color-gray-200) 63%
  );
  background-size: 400% 100%;
  animation: skeleton-loading 1.4s ease infinite;
}

@keyframes skeleton-loading {
  0% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0 50%;
  }
}

/* Progress Indicators */
.progress-bar {
  height: 4px;
  background-color: var(--color-gray-200);
  overflow: hidden;
}

.progress-bar__fill {
  height: 100%;
  background-color: var(--color-primary);
  animation: progress-fill 2s ease-in-out infinite;
}

@keyframes progress-fill {
  0% { width: 0; }
  100% { width: 100%; }
}

/* Form Submission Feedback */
.submit-success {
  animation: scale_in 0.3s ease-out;
  color: var(--color-success);
}

.submit-error {
  animation: shake 0.5s ease-in-out;
  color: var(--color-danger);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-10px); }
  75% { transform: translateX(10px); }
}