/* === StudyEng Unified Style === */

:root {
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --text-dark: #2d3748;
  --text-muted: #718096;
  --text-light: #a0aec0;
  --bg-light: #f7fafc;
  --border-light: #e2e8f0;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* Общие стили */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  color: var(--text-dark);
  background-color: #fff;
}

/* Контейнеры */
.container {
  max-width: 1200px;
}

/* Заголовки */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  color: var(--text-dark);
}

h1 { font-size: 32px; }
h2 { font-size: 28px; }
h3 { font-size: 24px; }
h4 { font-size: 22px; }
h5 { font-size: 18px; }

/* Навигация */
.navbar {
  border-radius: 0 0 12px 12px;
  background-color: #fff;
  transition: all 0.3s ease;
}

.navbar-brand {
  font-weight: 700;
  color: var(--text-dark) !important;
}

.nav-link {
  font-weight: 500;
  transition: color 0.3s ease;
}

.nav-link:hover {
  color: #667eea !important;
}

.dropdown-menu {
  border: none;
  border-radius: 12px;
  box-shadow: var(--shadow-md);
}

.dropdown-item {
  font-weight: 500;
  color: var(--text-dark);
  transition: background-color 0.3s ease, color 0.3s ease;
}

.dropdown-item:hover {
  background-color: var(--bg-light);
  color: #667eea;
}

/* Кнопки */
.btn {
  border-radius: 12px;
  font-weight: 600;
  transition: all 0.3s ease;
}

.course-btn {
  background: var(--primary-gradient);
  color: #fff;
  border: none;
  padding: 12px 28px;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.course-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
  color: #fff;
  text-decoration: none;
}

.btn-outline-primary {
  border-color: #667eea;
  color: #667eea;
}

.btn-outline-primary:hover {
  background: var(--primary-gradient);
  color: #fff;
}

/* Карточки */
.card {
  border: none;
  border-radius: 16px;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(102, 126, 234, 0.15);
}

/* Аккордеон */
.accordion-item {
  border: 1px solid var(--border-light);
  border-radius: 12px;
  background-color: #fff;
  transition: all 0.3s ease;
}

.accordion-item:hover {
  box-shadow: var(--shadow-md);
}

.accordion-button {
  background-color: #fff;
  color: var(--text-dark);
  font-weight: 600;
  border-radius: 12px;
  padding: 16px;
}

.accordion-button:not(.collapsed) {
  background: var(--bg-light);
  color: #667eea;
}

.accordion-button:focus {
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* Список */
.list-group-item {
  border: none;
  border-bottom: 1px solid var(--border-light);
  padding: 12px 16px;
  font-size: 14px;
  color: var(--text-dark);
}

.list-group-item a {
  color: #667eea;
  text-decoration: none;
  font-weight: 500;
}

.list-group-item a:hover {
  color: #764ba2;
  text-decoration: underline;
}

/* Alerts */
.alert {
  border-radius: 12px;
  font-size: 14px;
  background-color: var(--bg-light);
  border: 1px solid var(--border-light);
  color: var(--text-dark);
}

/* Карусель */
.carousel-control-prev,
.carousel-control-next {
  width: 5%;
  opacity: 0.8;
  background: none;
}

.carousel-control-prev-icon,
.carousel-control-next-icon {
  background: #fff;
  border: 2px solid #667eea;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  box-shadow: var(--shadow-sm);
}

.carousel-control-prev-icon::before,
.carousel-control-next-icon::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 12px;
  height: 12px;
  border-top: 3px solid var(--text-dark);
  border-right: 3px solid var(--text-dark);
}

.carousel-control-prev-icon::before {
  transform: translate(-50%, -50%) rotate(-135deg);
}

.carousel-control-next-icon::before {
  transform: translate(-50%, -50%) rotate(45deg);
}

.carousel-control-prev:hover,
.carousel-control-next:hover {
  opacity: 1;
}

/* Анимации */
.hover-scale {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hover-scale:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-md);
}

.hover-lift {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hover-lift:hover {
  transform: translateY(-5px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.12);
}

/* Адаптивность */
@media (max-width: 768px) {
  .carousel-control-prev {
    left: -20px;
  }
  .carousel-control-next {
    right: -20px;
  }
  .navbar-nav {
    text-align: center;
  }
  .dropdown-menu {
    text-align: center;
  }
}