/**
 * Loading States & Skeleton Screens System
 * پیاده‌سازی سیستم جامع Loading States برای بهبود تجربه کاربری
 */

/* ======================
   1. Skeleton Base Styles
   ====================== */

.skeleton {
  background: linear-gradient(90deg,
    #f0f0f0 0%,
    #f0f0f0 40%,
    #e0e0e0 50%,
    #e0e0e0 55%,
    #f0f0f0 65%,
    #f0f0f0 100%
  );
  background-size: 400% 100%;
  animation: skeleton-loading 1.8s ease-in-out infinite;
  border-radius: 4px;
  position: relative;
  overflow: hidden;
}

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

/* ======================
   2. Skeleton Components
   ====================== */

/* Skeleton Line */
.skeleton-line {
  height: 16px;
  margin-bottom: 12px;
  border-radius: 4px;
}

.skeleton-line--short {
  width: 60%;
}

.skeleton-line--medium {
  width: 80%;
}

.skeleton-line--long {
  width: 100%;
}

/* Skeleton Header */
.skeleton-header {
  height: 32px;
  width: 50%;
  margin-bottom: 20px;
  border-radius: 6px;
}

/* Skeleton Card */
.skeleton-card {
  padding: 20px;
  background: white;
  border-radius: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  margin-bottom: 16px;
}

/* Skeleton Circle (for avatars/icons) */
.skeleton-circle {
  width: 48px;
  height: 48px;
  border-radius: 50%;
}

/* Skeleton Rectangle */
.skeleton-rect {
  height: 200px;
  border-radius: 8px;
}

/* ======================
   3. Loading Overlay System
   ====================== */

.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  opacity: 1;
  transition: opacity 0.3s ease-out;
}

.loading-overlay.fade-out {
  opacity: 0;
  pointer-events: none;
}

.loading-overlay__content {
  text-align: center;
  max-width: 400px;
  padding: 0 20px;
}

/* ======================
   4. Spinner Animations
   ====================== */

/* Modern Spinner */
.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid #f3f4f6;
  border-top-color: #0ea5e9;
  border-radius: 50%;
  animation: spinner-rotate 0.8s linear infinite;
  margin: 0 auto 24px;
}

@keyframes spinner-rotate {
  to {
    transform: rotate(360deg);
  }
}

/* Dots Spinner */
.spinner-dots {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin: 0 auto 24px;
}

.spinner-dots__dot {
  width: 12px;
  height: 12px;
  background: #0ea5e9;
  border-radius: 50%;
  animation: spinner-dots-bounce 1.4s infinite ease-in-out both;
}

.spinner-dots__dot:nth-child(1) {
  animation-delay: -0.32s;
}

.spinner-dots__dot:nth-child(2) {
  animation-delay: -0.16s;
}

@keyframes spinner-dots-bounce {
  0%, 80%, 100% {
    transform: scale(0.6);
    opacity: 0.5;
  }
  40% {
    transform: scale(1);
    opacity: 1;
  }
}

/* Wave Spinner */
.spinner-wave {
  display: flex;
  gap: 4px;
  justify-content: center;
  margin: 0 auto 24px;
}

.spinner-wave__bar {
  width: 6px;
  height: 40px;
  background: #0ea5e9;
  border-radius: 3px;
  animation: spinner-wave 1.2s ease-in-out infinite;
}

.spinner-wave__bar:nth-child(1) { animation-delay: 0s; }
.spinner-wave__bar:nth-child(2) { animation-delay: 0.1s; }
.spinner-wave__bar:nth-child(3) { animation-delay: 0.2s; }
.spinner-wave__bar:nth-child(4) { animation-delay: 0.3s; }
.spinner-wave__bar:nth-child(5) { animation-delay: 0.4s; }

@keyframes spinner-wave {
  0%, 40%, 100% {
    transform: scaleY(0.4);
  }
  20% {
    transform: scaleY(1);
  }
}

/* ======================
   5. Loading Messages
   ====================== */

.loading-message {
  font-size: 18px;
  font-weight: 600;
  color: #1e293b;
  margin-bottom: 12px;
  animation: fade-in 0.3s ease-in;
}

.loading-submessage {
  font-size: 14px;
  color: #64748b;
  line-height: 1.6;
  animation: fade-in 0.3s ease-in 0.1s both;
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ======================
   6. Progress Indicators
   ====================== */

.loading-progress {
  width: 280px;
  height: 4px;
  background: #e2e8f0;
  border-radius: 2px;
  overflow: hidden;
  margin: 20px auto 0;
}

.loading-progress__bar {
  height: 100%;
  background: linear-gradient(90deg, #0ea5e9, #06b6d4);
  border-radius: 2px;
  animation: progress-loading 2s ease-in-out infinite;
}

@keyframes progress-loading {
  0% {
    width: 0%;
    margin-left: 0%;
  }
  50% {
    width: 70%;
    margin-left: 15%;
  }
  100% {
    width: 0%;
    margin-left: 100%;
  }
}

/* Determinate Progress */
.loading-progress__bar--determinate {
  animation: none;
  transition: width 0.3s ease-out;
}

/* ======================
   7. Component-Level Skeletons
   ====================== */

/* CLD Diagram Skeleton */
.skeleton-cld-diagram {
  width: 100%;
  min-height: 500px;
  background: linear-gradient(90deg, #f8fafc 0%, #f1f5f9 50%, #f8fafc 100%);
  background-size: 400% 100%;
  animation: skeleton-loading 2s ease-in-out infinite;
  border-radius: 12px;
  border: 2px dashed #cbd5e1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.skeleton-cld-diagram__content {
  text-align: center;
  color: #94a3b8;
}

/* Chart Skeleton */
.skeleton-chart {
  width: 100%;
  height: 300px;
  position: relative;
  background: #f8fafc;
  border-radius: 8px;
  overflow: hidden;
}

.skeleton-chart__bars {
  display: flex;
  align-items: flex-end;
  justify-content: space-around;
  height: 100%;
  padding: 20px;
}

.skeleton-chart__bar {
  width: 40px;
  background: linear-gradient(180deg, #e2e8f0, #cbd5e1);
  border-radius: 4px 4px 0 0;
  animation: skeleton-loading 1.8s ease-in-out infinite;
}

.skeleton-chart__bar:nth-child(1) { height: 60%; animation-delay: 0s; }
.skeleton-chart__bar:nth-child(2) { height: 85%; animation-delay: 0.2s; }
.skeleton-chart__bar:nth-child(3) { height: 70%; animation-delay: 0.4s; }
.skeleton-chart__bar:nth-child(4) { height: 95%; animation-delay: 0.6s; }
.skeleton-chart__bar:nth-child(5) { height: 55%; animation-delay: 0.8s; }

/* Table Skeleton */
.skeleton-table {
  width: 100%;
  border-collapse: collapse;
}

.skeleton-table__row {
  border-bottom: 1px solid #e2e8f0;
}

.skeleton-table__cell {
  padding: 12px;
}

.skeleton-table__cell-content {
  height: 14px;
  background: linear-gradient(90deg, #f0f0f0 40%, #e0e0e0 50%, #f0f0f0 60%);
  background-size: 400% 100%;
  animation: skeleton-loading 1.8s ease-in-out infinite;
  border-radius: 4px;
}

/* ======================
   8. Utility Classes
   ====================== */

.loading-hide {
  display: none !important;
}

.loading-blur {
  filter: blur(4px);
  pointer-events: none;
  user-select: none;
}

/* Pulse Animation for Icons */
.loading-pulse {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

/* ======================
   9. Responsive Design
   ====================== */

@media (max-width: 768px) {
  .loading-overlay__content {
    padding: 0 16px;
  }

  .loading-message {
    font-size: 16px;
  }

  .loading-submessage {
    font-size: 13px;
  }

  .spinner {
    width: 40px;
    height: 40px;
  }

  .loading-progress {
    width: 240px;
  }
}

/* ======================
   10. Dark Mode Support
   ====================== */

@media (prefers-color-scheme: dark) {
  .skeleton {
    background: linear-gradient(90deg,
      #1e293b 0%,
      #1e293b 40%,
      #334155 50%,
      #334155 55%,
      #1e293b 65%,
      #1e293b 100%
    );
  }

  .loading-overlay {
    background: rgba(15, 23, 42, 0.95);
  }

  .skeleton-card {
    background: #1e293b;
  }

  .loading-message {
    color: #f1f5f9;
  }

  .loading-submessage {
    color: #94a3b8;
  }

  .skeleton-cld-diagram {
    background: linear-gradient(90deg, #1e293b 0%, #334155 50%, #1e293b 100%);
    border-color: #475569;
  }

  .skeleton-cld-diagram__content {
    color: #64748b;
  }
}

/* ======================
   11. Accessibility
   ====================== */

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  .skeleton,
  .spinner,
  .spinner-dots__dot,
  .spinner-wave__bar,
  .loading-progress__bar {
    animation-duration: 3s;
  }

  .loading-message,
  .loading-submessage {
    animation: none;
  }
}

/* Screen reader only content */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}