@font-face {
  font-family: 'Vazir';
  src: url('../assets/fonts/vazir-font-v16.1.0/Vazir.woff2') format('woff2'),
    url('../assets/fonts/vazir-font-v16.1.0/Vazir.woff') format('woff');
  font-weight: normal;
  font-style: normal;
  font-display: swap;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

:root {
  /* Colors */
  --white: #ffffff;
  --bg-dark: #0f172a;

  /* Gradient Colors */
  --color-indigo: #6366f1;
  --color-purple: #8b5cf6;
  --color-pink: #d946ef;
  --color-rose: #ec4899;
  --color-amber: #f59e0b;
  --color-yellow: #fbbf24;

  /* Gradients */
  --primary-gradient: linear-gradient(
    135deg,
    var(--color-indigo) 0%,
    var(--color-purple) 50%,
    var(--color-pink) 100%
  );
  --title-gradient: linear-gradient(
    135deg,
    var(--color-yellow) 0%,
    var(--color-amber) 25%,
    var(--color-rose) 50%,
    #a855f7 75%,
    var(--color-indigo) 100%
  );
  --rainbow-gradient: linear-gradient(
    90deg,
    var(--color-indigo),
    var(--color-purple),
    var(--color-pink),
    var(--color-rose),
    var(--color-amber)
  );

  /* Glass Effect */
  --glass-bg: rgba(255, 255, 255, 0.12);
  --glass-bg-hover: rgba(139, 92, 246, 0.2);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-border-hover: rgba(139, 92, 246, 0.5);

  /* Shadows */
  --shadow-light: 0 10px 40px 0 rgba(0, 0, 0, 0.12);
  --shadow-medium: 0 20px 50px 0 rgba(0, 0, 0, 0.2);
  --shadow-heavy: 0 30px 70px 0 rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 10px 30px rgba(139, 92, 246, 0.3);
  --shadow-glow-hover: 0 15px 45px rgba(139, 92, 246, 0.5);

  /* Spacing */
  --spacing-xs: 10px;
  --spacing-sm: 15px;
  --spacing-md: 20px;
  --spacing-lg: 30px;
  --spacing-xl: 40px;
  --spacing-2xl: 60px;

  /* Border Radius */
  --radius-sm: 25px;
  --radius-md: 30px;
  --radius-lg: 50px;
  --radius-full: 50%;

  /* Typography */
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;

  /* Transitions */
  --transition-fast: 0.15s;
  --transition-normal: 0.2s;
  --transition-slow: 0.25s;
  --transition-ease: cubic-bezier(0.25, 0.8, 0.25, 1);

  /* Opacity */
  --opacity-high: 0.95;
  --opacity-medium: 0.85;
  --opacity-low: 0.7;
  --opacity-very-low: 0.5;
}

body {
  font-family: 'Vazir', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
    'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-dark);
  min-height: 100vh;
  padding: var(--spacing-md);
  direction: rtl;
  position: relative;
  overflow-x: hidden;
}

body::after {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(
      ellipse at top,
      rgba(99, 102, 241, 0.2) 0%,
      transparent 50%
    ),
    radial-gradient(
      ellipse at bottom,
      rgba(217, 70, 239, 0.2) 0%,
      transparent 50%
    );
  pointer-events: none;
  z-index: 0;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

/* Header Styles */
.header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  animation: fadeInDown 0.3s ease;
  position: relative;
}

.main-title {
  padding-top: 2rem;
  font-size: 4rem;
  font-weight: var(--font-weight-extrabold);
  background: var(--title-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--spacing-sm);
  filter: drop-shadow(0 10px 30px rgba(139, 92, 246, 0.4));
  animation: float 3s ease-in-out infinite;
  letter-spacing: -1px;
}

.subtitle {
  font-size: 1.8rem;
  color: rgba(255, 255, 255, var(--opacity-high));
  font-weight: var(--font-weight-light);
  letter-spacing: 0.5px;
}

.logo {
  position: absolute;
  top: -1rem;
  right: -1rem;
  width: 5rem;
  height: auto;
  filter: drop-shadow(0 8px 25px rgba(139, 92, 246, 0.5));
  transition: transform 0.15s ease;
  z-index: 1;
}

.logo:hover {
  transform: scale(1.1);
  filter: drop-shadow(0 12px 35px rgba(139, 92, 246, var(--opacity-low)));
}

.course-title,
.lesson-title {
  font-size: 3rem;
  font-weight: var(--font-weight-bold);
  color: var(--white);
  margin-bottom: var(--spacing-sm);
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  animation: slideInRight 0.3s ease;
}

.course-description {
  font-size: 1.4rem;
  color: rgba(255, 255, 255, 0.9);
  font-weight: var(--font-weight-light);
  margin-top: var(--spacing-xs);
}

/* Back Button */
.back-button {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 14px 32px;
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.3),
    rgba(139, 92, 246, 0.3)
  );
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(139, 92, 246, 0.4);
  color: var(--white);
  text-decoration: none;
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-lg);
  font-weight: var(--font-weight-semibold);
  font-size: 1.1rem;
  transition: all var(--transition-fast) var(--transition-ease);
  box-shadow: var(--shadow-glow);
  position: relative;
  overflow: hidden;
}

.back-button::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.2),
    transparent
  );
  transition: left var(--transition-slow);
}

.back-button:hover::before {
  left: 100%;
}

.back-button:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: var(--shadow-glow-hover);
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, var(--opacity-very-low)),
    rgba(139, 92, 246, var(--opacity-very-low))
  );
  border-color: var(--glass-border-hover);
}

.course-card {
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 50px var(--spacing-xl);
  text-align: center;
  cursor: pointer;
  transition: transform var(--transition-fast) ease,
    box-shadow var(--transition-fast) ease;
  box-shadow: var(--shadow-light);
  text-decoration: none;
  color: var(--white);
  position: relative;
  overflow: hidden;
  animation: fadeInUp 0.3s ease backwards;
}

.course-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1),
    rgba(255, 255, 255, 0.05)
  );
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.course-card:hover::before {
  opacity: 1;
}

.course-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background: var(--rainbow-gradient);
  transform: scaleX(0);
  transition: transform var(--transition-fast) ease;
}

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

.course-card:hover {
  transform: translateY(-10px) scale(1.05);
  box-shadow: 0 20px 50px rgba(139, 92, 246, 0.35);
  background: var(--glass-bg-hover);
  border-color: var(--glass-border-hover);
}

.course-card.coming-soon {
  opacity: var(--opacity-very-low);
  cursor: not-allowed;
  filter: grayscale(var(--opacity-very-low));
}

.course-card.coming-soon:hover {
  transform: none;
}

.course-icon {
  font-size: 6rem;
  margin-bottom: var(--spacing-sm);
  display: block;
  animation: float 3s ease-in-out infinite;
  filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.3));
}

.course-name {
  font-size: 2rem;
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-sm);
  color: var(--white);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.course-desc {
  font-size: 1.2rem;
  color: rgba(255, 255, 255, var(--opacity-medium));
  margin-bottom: var(--spacing-sm);
  font-weight: var(--font-weight-light);
  line-height: 1.6;
}

.course-lessons-count {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: var(--spacing-xs) var(--spacing-md);
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.3),
    rgba(139, 92, 246, 0.3)
  );
  border: 1px solid rgba(139, 92, 246, 0.4);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  color: var(--white);
  font-weight: var(--font-weight-semibold);
  backdrop-filter: blur(10px);
  box-shadow: 0 4px 15px rgba(139, 92, 246, 0.2);
}

/* Category Cards Styles */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--spacing-xl);
  margin-top: var(--spacing-xl);
}

.category-card {
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 40px var(--spacing-xl);
  text-align: center;
  cursor: pointer;
  transition: transform var(--transition-fast) ease,
    box-shadow var(--transition-fast) ease;
  box-shadow: var(--shadow-light);
  text-decoration: none;
  color: var(--white);
  position: relative;
  overflow: hidden;
  animation: fadeInUp 0.3s ease backwards;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1),
    rgba(255, 255, 255, 0.05)
  );
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.category-card:hover::before {
  opacity: 1;
}

.category-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background: var(--rainbow-gradient);
  transform: scaleX(0);
  transition: transform var(--transition-fast) ease;
}

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

.category-card:hover {
  transform: translateY(-10px) scale(1.03);
  box-shadow: 0 20px 50px rgba(139, 92, 246, 0.35);
  background: var(--glass-bg-hover);
  border-color: var(--glass-border-hover);
}

.category-icon {
  font-size: 5rem;
  margin-bottom: var(--spacing-sm);
  display: block;
  animation: float 3s ease-in-out infinite;
  filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.3));
}

.category-name {
  font-size: 1.8rem;
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-md);
  background: var(--title-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.category-courses-list {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--spacing-md) 0;
  width: 100%;
  text-align: right;
}

.category-course-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 10px 15px;
  margin-bottom: 8px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 15px;
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.9);
  transition: background var(--transition-fast);
}

.category-card:hover .category-course-item {
  background: rgba(255, 255, 255, 0.1);
}

.course-bullet {
  font-size: 1.3rem;
}

.category-arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  height: 50px;
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.4),
    rgba(139, 92, 246, 0.4)
  );
  border-radius: var(--radius-full);
  font-size: 1.5rem;
  margin-top: auto;
  transition: transform var(--transition-fast),
    background var(--transition-fast);
}

.category-card:hover .category-arrow {
  transform: translateX(-10px);
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.6),
    rgba(139, 92, 246, 0.6)
  );
}

/* About Us Section */
.about-section {
  margin-top: 80px;
  margin-bottom: var(--spacing-2xl);
  padding: 50px var(--spacing-xl);
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-light);
  animation: fadeInUp 0.3s ease backwards;
  animation-delay: 0.2s;
}

.about-content {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.about-text {
  font-size: 1.3rem;
  color: rgba(255, 255, 255, 0.9);
  line-height: 2;
  margin-bottom: var(--spacing-md);
  font-weight: var(--font-weight-light);
}

.about-text strong {
  background: linear-gradient(
    135deg,
    var(--color-yellow) 0%,
    var(--color-amber) 50%,
    var(--color-rose) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: var(--font-weight-bold);
}

/* Contact Us Section */
.contact-section {
  margin-bottom: var(--spacing-2xl);
  padding: 50px var(--spacing-xl);
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-light);
  animation: fadeInUp 0.3s ease backwards;
  animation-delay: 0.25s;
}

.contact-content {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.contact-text {
  font-size: 1.3rem;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: var(--spacing-lg);
  font-weight: var(--font-weight-light);
  line-height: 1.8;
}

.whatsapp-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  align-items: center;
  margin-top: var(--spacing-lg);
}

.whatsapp-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: 18px var(--spacing-xl);
  background: linear-gradient(
    135deg,
    rgba(37, 211, 102, 0.3),
    rgba(18, 183, 91, 0.3)
  );
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 2px solid rgba(37, 211, 102, 0.6);
  border-radius: var(--radius-lg);
  color: var(--white);
  text-decoration: none;
  font-size: 1.2rem;
  font-weight: var(--font-weight-bold);
  transition: all var(--transition-normal) var(--transition-ease);
  box-shadow: 0 8px 25px rgba(37, 211, 102, 0.4);
  position: relative;
  overflow: hidden;
  min-width: 300px;
  justify-content: center;
}

.whatsapp-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.3),
    transparent
  );
  transition: left var(--transition-slow);
}

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

.whatsapp-btn:hover {
  transform: translateY(-5px) scale(1.03);
  box-shadow: 0 15px 40px rgba(37, 211, 102, 0.5);
  background: linear-gradient(
    135deg,
    rgba(37, 211, 102, 0.4),
    rgba(18, 183, 91, 0.4)
  );
  border-color: rgba(37, 211, 102, 0.8);
}

.whatsapp-icon {
  font-size: 1.8rem;
  color: #25d366;
  filter: drop-shadow(0 2px 8px rgba(37, 211, 102, 0.6));
}

/* Lessons Grid */
.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-sm);
  margin-top: var(--spacing-xl);
}

.lesson-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: var(--spacing-lg) var(--spacing-md);
  text-align: center;
  cursor: pointer;
  transition: transform var(--transition-fast) ease,
    box-shadow var(--transition-fast) ease;
  box-shadow: var(--shadow-light);
  text-decoration: none;
  color: var(--white);
  animation: fadeInUp 0.25s ease backwards;
  position: relative;
  overflow: hidden;
}

.lesson-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--rainbow-gradient);
  transform: scaleX(0);
  transition: transform var(--transition-fast) ease;
}

.lesson-card:hover::before {
  transform: scaleX(1);
}

.lesson-card:hover {
  transform: translateY(-10px) scale(1.05);
  box-shadow: 0 20px 50px rgba(139, 92, 246, 0.35);
  background: var(--glass-bg-hover);
  border-color: var(--glass-border-hover);
}

.lesson-number {
  font-size: 3rem;
  font-weight: var(--font-weight-extrabold);
  background: linear-gradient(135deg, #ffffff 0%, #e0e7ff 50%, #ddd6fe 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--spacing-xs);
  filter: drop-shadow(0 4px 10px rgba(139, 92, 246, 0.4));
}

.lesson-name {
  font-size: 1.1rem;
  font-weight: var(--font-weight-semibold);
  color: var(--white);
  margin-bottom: 8px;
}

.lesson-info {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, var(--opacity-low));
  font-weight: var(--font-weight-light);
}

/* Lesson Content */
.lesson-content {
  margin-top: 40px;
}

.section-title {
  font-size: 2.5rem;
  font-weight: var(--font-weight-bold);
  color: var(--white);
  margin-bottom: 35px;
  text-align: center;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  position: relative;
  display: inline-block;
  width: 100%;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 100px;
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--color-indigo),
    var(--color-purple),
    var(--color-pink)
  );
  border-radius: 2px;
  box-shadow: 0 2px 10px rgba(139, 92, 246, var(--opacity-very-low));
}

.images-section,
.homework-section {
  margin-bottom: var(--spacing-2xl);
}

.images-grid {
  display: grid;
  gap: 35px;
}

.image-card {
  background: var(--glass-bg);
  backdrop-filter: blur(25px);
  -webkit-backdrop-filter: blur(25px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-light);
  transition: all var(--transition-fast) cubic-bezier(0.175, 0.885, 0.32, 1.275);
  animation: fadeIn 0.3s ease backwards;
  position: relative;
  min-height: 200px;
}

/* Skeleton داخل کارت تصویر */
.image-card.loading .image-skeleton-inner {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  min-height: 300px;
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0.05) 0%,
    rgba(255, 255, 255, 0.15) 50%,
    rgba(255, 255, 255, 0.05) 100%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  z-index: 2;
}

.image-card.loading .lesson-image {
  opacity: 0;
}

.image-card.loaded .image-skeleton-inner {
  display: none;
}

.image-card.loaded .lesson-image {
  opacity: 1;
  transition: opacity 0.3s ease;
}

.image-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.1), transparent);
  opacity: 0;
  transition: opacity var(--transition-fast);
  pointer-events: none;
  z-index: 1;
}

.image-card:hover::before {
  opacity: 1;
}

.image-card:hover {
  transform: translateY(-10px) scale(1.02);
  box-shadow: 0 30px 70px rgba(139, 92, 246, 0.4);
  border-color: var(--glass-border-hover);
}

.lesson-image {
  width: 100%;
  height: auto;
  display: block;
}

.footer {
  text-align: center;
  padding: var(--spacing-md) 0;
  color: rgba(255, 255, 255, var(--opacity-low));
  font-size: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: var(--spacing-2xl);
}

/* Lesson Navigation Buttons */
.lesson-navigation {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-md);
  margin: var(--spacing-xl) 0;
  flex-wrap: wrap;
}

.nav-button {
  flex: 0 1 auto;
  min-width: 150px;
  text-align: center;
  display: flex;
  justify-content: center;
  align-items: center;
}

.nav-button:disabled,
.nav-button.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* Lesson Footer with WhatsApp Icons */
.lesson-footer {
  text-align: center;
  padding: var(--spacing-lg) var(--spacing-md);
  margin-top: var(--spacing-2xl);
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-light);
}

.footer-text {
  color: rgba(255, 255, 255, 0.9);
  font-size: 1.1rem;
  margin-bottom: var(--spacing-md);
  font-weight: var(--font-weight-light);
}

.footer-whatsapp {
  display: flex;
  gap: 25px;
  justify-content: center;
  align-items: center;
}

.whatsapp-icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 70px;
  height: 70px;
  background: linear-gradient(
    135deg,
    rgba(37, 211, 102, 0.3),
    rgba(18, 183, 91, 0.3)
  );
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  border: 2px solid rgba(37, 211, 102, 0.6);
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: all var(--transition-normal) var(--transition-ease);
  box-shadow: 0 8px 25px rgba(37, 211, 102, 0.4);
  position: relative;
  overflow: hidden;
}

.whatsapp-icon-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.3),
    transparent
  );
  transition: left var(--transition-slow);
}

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

.whatsapp-icon-btn:hover {
  transform: translateY(-5px) scale(1.1);
  box-shadow: 0 15px 40px rgba(37, 211, 102, 0.5);
  background: linear-gradient(
    135deg,
    rgba(37, 211, 102, 0.4),
    rgba(18, 183, 91, 0.4)
  );
  border-color: rgba(37, 211, 102, 0.8);
}

.wa-icon {
  font-size: 1.8rem;
  color: #ffffff;
  filter: drop-shadow(0 2px 8px rgba(37, 211, 102, 0.6));
}

/* Animations */

@keyframes float {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-20px);
  }
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .main-title {
    font-size: 2.5rem;
  }

  .subtitle {
    font-size: 1.3rem;
  }

  .course-title,
  .lesson-title {
    font-size: 2rem;
  }

  .courses-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }

  .lessons-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--spacing-md);
  }

  .course-card {
    padding: var(--spacing-xl) var(--spacing-lg);
  }

  .course-icon {
    font-size: 4.5rem;
  }

  .course-name {
    font-size: 1.6rem;
  }

  .lesson-number {
    font-size: 2.5rem;
  }

  .section-title {
    font-size: 2rem;
  }

  .about-section,
  .contact-section {
    padding: 35px var(--spacing-sm);
    margin-top: 50px;
  }

  .about-text,
  .contact-text {
    font-size: 1.1rem;
  }

  .whatsapp-btn {
    min-width: 250px;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 1.1rem;
  }

  .whatsapp-links {
    gap: var(--spacing-sm);
  }

  .lesson-footer {
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .footer-text {
    font-size: 1rem;
  }

  .whatsapp-icon-btn {
    width: 60px;
    height: 60px;
  }

  .wa-icon {
    font-size: 1.8rem;
  }
}

@media (max-width: 480px) {
  body {
    padding: var(--spacing-sm);
  }

  .main-title {
    font-size: 2rem;
  }

  .subtitle {
    font-size: 1.1rem;
  }

  .lessons-grid {
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: var(--spacing-sm);
  }

  .back-button {
    padding: 12px 24px;
    font-size: 1rem;
  }

  .course-icon {
    font-size: 3.5rem;
  }

  .lesson-card {
    padding: var(--spacing-md) var(--spacing-sm);
  }

  .lesson-number {
    font-size: 2rem;
  }

  .about-section,
  .contact-section {
    padding: var(--spacing-sm) var(--spacing-md);
    margin-top: var(--spacing-xl);
  }

  .about-text,
  .contact-text {
    font-size: 1rem;
    line-height: 1.8;
  }

  .whatsapp-btn {
    min-width: 100%;
    padding: 14px var(--spacing-sm);
    font-size: 1rem;
  }

  .whatsapp-icon {
    font-size: 1.5rem;
  }

  .lesson-footer {
    padding: var(--spacing-md) var(--spacing-sm);
  }

  .footer-text {
    font-size: 0.95rem;
    margin-bottom: var(--spacing-sm);
  }

  .footer-whatsapp {
    gap: var(--spacing-md);
  }

  .whatsapp-icon-btn {
    width: 55px;
    height: 55px;
  }

  .wa-icon {
    font-size: 1.6rem;
  }

  .lesson-navigation {
    flex-direction: column;
    text-align: center;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
  }

  .nav-button {
    width: 100%;
    max-width: 300px;
  }
}

/* Loading State */
.loading {
  text-align: center;
  padding: 80px;
  color: var(--white);
  font-size: 1.8rem;
  font-weight: var(--font-weight-light);
}

.loading::after {
  content: '';
  display: block;
  margin: var(--spacing-lg) auto;
  width: 50px;
  height: 50px;
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-top-color: var(--white);
  border-radius: var(--radius-full);
  animation: spin 0.5s linear infinite;
}

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

/* ============================================
   SKELETON LOADING STYLES
   ============================================ */

/* Base Skeleton Animation */
@keyframes skeleton-shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

.skeleton {
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0.05) 0%,
    rgba(255, 255, 255, 0.15) 50%,
    rgba(255, 255, 255, 0.05) 100%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

/* Category Card Skeleton */
.category-card-skeleton {
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 40px var(--spacing-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: fadeInUp 0.3s ease backwards;
}

.category-card-skeleton .skeleton-icon {
  width: 80px;
  height: 80px;
  border-radius: var(--radius-full);
  margin-bottom: var(--spacing-sm);
}

.category-card-skeleton .skeleton-title {
  width: 60%;
  height: 28px;
  margin-bottom: var(--spacing-md);
}

.category-card-skeleton .skeleton-list {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.category-card-skeleton .skeleton-list-item {
  width: 100%;
  height: 45px;
  border-radius: 15px;
}

.category-card-skeleton .skeleton-arrow {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-full);
  margin-top: var(--spacing-md);
}

/* Course Card Skeleton */
.course-card-skeleton {
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 50px var(--spacing-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: fadeInUp 0.3s ease backwards;
}

.course-card-skeleton .skeleton-icon {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-full);
  margin-bottom: var(--spacing-sm);
}

.course-card-skeleton .skeleton-title {
  width: 70%;
  height: 32px;
  margin-bottom: var(--spacing-sm);
}

.course-card-skeleton .skeleton-desc {
  width: 90%;
  height: 20px;
  margin-bottom: 8px;
}

.course-card-skeleton .skeleton-desc-short {
  width: 60%;
  height: 20px;
  margin-bottom: var(--spacing-sm);
}

.course-card-skeleton .skeleton-badge {
  width: 120px;
  height: 40px;
  border-radius: var(--radius-sm);
}

/* Lesson Card Skeleton */
.lesson-card-skeleton {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: var(--spacing-lg) var(--spacing-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: fadeInUp 0.25s ease backwards;
}

.lesson-card-skeleton .skeleton-number {
  width: 60px;
  height: 50px;
  border-radius: 10px;
  margin-bottom: var(--spacing-xs);
}

.lesson-card-skeleton .skeleton-name {
  width: 80%;
  height: 18px;
  margin-bottom: 8px;
}

.lesson-card-skeleton .skeleton-info {
  width: 60%;
  height: 14px;
}

/* Image Card Skeleton */
.image-card-skeleton {
  background: var(--glass-bg);
  backdrop-filter: blur(25px);
  -webkit-backdrop-filter: blur(25px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  animation: fadeIn 0.3s ease backwards;
}

.image-card-skeleton .skeleton-image {
  width: 100%;
  height: 300px;
  border-radius: 0;
}

/* Video Card Skeleton */
.video-card-skeleton {
  background: var(--glass-bg);
  backdrop-filter: blur(25px);
  -webkit-backdrop-filter: blur(25px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  animation: fadeIn 0.3s ease backwards;
}

.video-card-skeleton .skeleton-video {
  width: 100%;
  height: 250px;
  border-radius: 0;
}

.video-card-skeleton .skeleton-video-title {
  width: 70%;
  height: 24px;
  margin: var(--spacing-md) auto;
}

/* Audio Card Skeleton */
.audio-card-skeleton {
  background: var(--glass-bg);
  backdrop-filter: blur(25px);
  -webkit-backdrop-filter: blur(25px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: fadeIn 0.3s ease backwards;
}

.audio-card-skeleton .skeleton-audio-icon {
  width: 70px;
  height: 70px;
  border-radius: var(--radius-full);
  margin-bottom: var(--spacing-sm);
}

.audio-card-skeleton .skeleton-audio-title {
  width: 60%;
  height: 22px;
  margin-bottom: var(--spacing-md);
}

.audio-card-skeleton .skeleton-audio-player {
  width: 100%;
  height: 50px;
}

/* Header Skeleton */
.header-skeleton {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  animation: fadeInDown 0.3s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.header-skeleton .skeleton-main-title {
  width: 300px;
  height: 50px;
  margin-bottom: var(--spacing-sm);
}

.header-skeleton .skeleton-subtitle {
  width: 250px;
  height: 28px;
  margin-bottom: 8px;
}

.header-skeleton .skeleton-subtitle-small {
  width: 200px;
  height: 24px;
}

/* About Section Skeleton */
.about-skeleton {
  margin-top: 80px;
  margin-bottom: var(--spacing-2xl);
  padding: 50px var(--spacing-xl);
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: fadeInUp 0.3s ease backwards;
}

.about-skeleton .skeleton-section-title {
  width: 200px;
  height: 40px;
  margin-bottom: var(--spacing-lg);
}

.about-skeleton .skeleton-text {
  width: 90%;
  height: 20px;
  margin-bottom: var(--spacing-sm);
}

.about-skeleton .skeleton-text:nth-child(3) {
  width: 80%;
}

.about-skeleton .skeleton-text:nth-child(4) {
  width: 85%;
}

.about-skeleton .skeleton-text:last-child {
  width: 60%;
}

/* Contact Section Skeleton */
.contact-skeleton {
  margin-bottom: var(--spacing-2xl);
  padding: 50px var(--spacing-xl);
  background: var(--glass-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: fadeInUp 0.3s ease backwards;
}

.contact-skeleton .skeleton-section-title {
  width: 180px;
  height: 40px;
  margin-bottom: var(--spacing-lg);
}

.contact-skeleton .skeleton-contact-text {
  width: 70%;
  height: 20px;
  margin-bottom: var(--spacing-lg);
}

.contact-skeleton .skeleton-whatsapp-btn {
  width: 300px;
  height: 56px;
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-md);
}

/* Section Title Skeleton */
.section-title-skeleton {
  width: 200px;
  height: 40px;
  margin: 0 auto var(--spacing-lg);
}

/* Responsive Skeleton */
@media (max-width: 768px) {
  .category-card-skeleton .skeleton-icon,
  .course-card-skeleton .skeleton-icon {
    width: 70px;
    height: 70px;
  }

  .header-skeleton .skeleton-main-title {
    width: 200px;
    height: 40px;
  }

  .header-skeleton .skeleton-subtitle {
    width: 180px;
    height: 22px;
  }

  .image-card-skeleton .skeleton-image {
    height: 200px;
  }

  .image-card.loading .image-skeleton-inner {
    min-height: 200px;
  }

  .video-card-skeleton .skeleton-video {
    height: 180px;
  }
}

@media (max-width: 480px) {
  .header-skeleton .skeleton-main-title {
    width: 150px;
    height: 32px;
  }

  .image-card-skeleton .skeleton-image {
    height: 150px;
  }

  .image-card.loading .image-skeleton-inner {
    min-height: 150px;
  }

  .contact-skeleton .skeleton-whatsapp-btn {
    width: 100%;
  }
}

/* ============================================
   END SKELETON LOADING STYLES
   ============================================ */

/* Hidden by default */
.homework-section.hidden {
  display: none;
}

/* ============================================
   VIDEO & AUDIO PLAYER STYLES
   ============================================ */

/* Video Section */
.videos-section,
.audios-section {
  margin-bottom: var(--spacing-2xl);
}

.media-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--spacing-lg);
}

/* Video Card */
.video-card {
  background: var(--glass-bg);
  backdrop-filter: blur(25px);
  -webkit-backdrop-filter: blur(25px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-light);
  transition: all var(--transition-fast) cubic-bezier(0.175, 0.885, 0.32, 1.275);
  animation: fadeIn 0.3s ease backwards;
}

.video-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 25px 60px rgba(139, 92, 246, 0.35);
  border-color: var(--glass-border-hover);
}

.video-wrapper {
  position: relative;
  width: 100%;
  background: rgba(0, 0, 0, 0.3);
}

.lesson-video {
  width: 100%;
  height: auto;
  display: block;
  max-height: 400px;
  object-fit: contain;
  background: #000;
}

.video-title {
  padding: var(--spacing-md);
  margin: 0;
  font-size: 1.2rem;
  font-weight: var(--font-weight-semibold);
  color: var(--white);
  text-align: center;
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.2),
    rgba(139, 92, 246, 0.2)
  );
  border-top: 1px solid var(--glass-border);
}

/* Audio Card */
.audio-card {
  background: var(--glass-bg);
  backdrop-filter: blur(25px);
  -webkit-backdrop-filter: blur(25px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-light);
  transition: all var(--transition-fast) cubic-bezier(0.175, 0.885, 0.32, 1.275);
  animation: fadeIn 0.3s ease backwards;
  text-align: center;
}

.audio-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 25px 60px rgba(139, 92, 246, 0.35);
  border-color: var(--glass-border-hover);
}

.audio-icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-sm);
  animation: float 3s ease-in-out infinite;
  filter: drop-shadow(0 8px 20px rgba(139, 92, 246, 0.4));
}

.audio-title {
  font-size: 1.3rem;
  font-weight: var(--font-weight-semibold);
  color: var(--white);
  margin-bottom: var(--spacing-md);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.lesson-audio {
  width: 100%;
  height: 50px;
  border-radius: var(--radius-sm);
  outline: none;
}

/* Custom Audio Styling for Webkit browsers */
.lesson-audio::-webkit-media-controls-panel {
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.3),
    rgba(139, 92, 246, 0.3)
  );
  border-radius: var(--radius-sm);
}

.lesson-audio::-webkit-media-controls-play-button,
.lesson-audio::-webkit-media-controls-mute-button {
  filter: invert(1);
}

.lesson-audio::-webkit-media-controls-current-time-display,
.lesson-audio::-webkit-media-controls-time-remaining-display {
  color: var(--white);
}

/* Responsive Media Grid */
@media (max-width: 768px) {
  .media-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .lesson-video {
    max-height: 300px;
  }

  .video-title {
    font-size: 1rem;
    padding: var(--spacing-sm);
  }

  .audio-icon {
    font-size: 3rem;
  }

  .audio-title {
    font-size: 1.1rem;
  }

  .audio-card {
    padding: var(--spacing-md);
  }
}

@media (max-width: 480px) {
  .media-grid {
    grid-template-columns: 1fr;
  }

  .lesson-video {
    max-height: 250px;
  }

  .video-card:hover,
  .audio-card:hover {
    transform: translateY(-4px) scale(1.01);
  }
}

/* ============================================
   END VIDEO & AUDIO STYLES
   ============================================ */

/* Scroll to Top Button */
.scroll-to-top {
  position: fixed;
  bottom: var(--spacing-lg);
  left: var(--spacing-lg);
  width: 50px;
  height: 50px;
  background: var(--primary-gradient);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: var(--white);
  box-shadow: var(--shadow-medium);
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transform: translateY(100px);
  transition: all var(--transition-normal) ease;
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-to-top:hover {
  transform: translateY(-5px) scale(1.1);
  box-shadow: var(--shadow-heavy);
}

.scroll-to-top:active {
  transform: translateY(-2px) scale(1.05);
}

@media (max-width: 768px) {
  .scroll-to-top {
    bottom: var(--spacing-md);
    left: var(--spacing-md);
    width: 45px;
    height: 45px;
    font-size: 20px;
  }
}