/* =============================================
   TECHROBOT — главный файл стилей
   Дипломный проект: Информационный сайт о технологиях и робототехнике
   Автор: студент группы
   ============================================= */

/* === Импорт шрифтов === */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Montserrat:wght@700;800;900&display=swap');

/* =============================================
   CSS-переменные (дизайн-токены)
   ============================================= */
:root {
  /* Основные цвета */
  --primary: #00d4ff;
  --primary-dark: #00a8cc;
  --primary-glow: rgba(0, 212, 255, 0.2);
  --secondary: #7b2fff;
  --secondary-glow: rgba(123, 47, 255, 0.2);

  /* Градиенты */
  --gradient-primary: linear-gradient(135deg, #00d4ff, #7b2fff);
  --gradient-hero: linear-gradient(135deg, rgba(0, 212, 255, 0.1) 0%, rgba(123, 47, 255, 0.1) 100%);
  --gradient-card: linear-gradient(180deg, transparent 40%, rgba(0, 0, 0, 0.8) 100%);

  /* Фоновые цвета */
  --bg-dark: #0a0a0f;
  --bg-dark2: #0d0d15;
  --bg-card: #12121c;
  --bg-card-hover: #1a1a28;
  --bg-input: #16161f;

  /* Цвета текста */
  --text-primary: #f0f0ff;
  --text-secondary: #9090b0;
  --text-muted: #5a5a7a;

  /* Границы и разделители */
  --border: #2a2a40;
  --border-hover: #404060;

  /* Тени */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 30px rgba(0, 212, 255, 0.15);

  /* Типография */
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-heading: 'Montserrat', 'Inter', sans-serif;

  /* Размеры */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --container: 1280px;

  /* Анимации */
  --transition: 0.25s ease;
  --transition-slow: 0.4s ease;

  /* Категории — цвета */
  --cat-ai: #00d4ff;
  --cat-robotics: #7b2fff;
  --cat-iot: #00ff88;
  --cat-vrar: #ff6b35;
  --cat-biotech: #ff2d78;
  --cat-drones: #ffcc00;
}

/* =============================================
   Сброс стилей и базовые настройки
   ============================================= */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  /* Кастомный скроллбар */
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

/* Кастомный скроллбар для Webkit */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

/* =============================================
   Базовые типографические стили
   ============================================= */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.5rem); }
h4 { font-size: 1.1rem; }

p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--primary-dark);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.4rem;
  color: var(--text-secondary);
}

/* =============================================
   Утилитарные классы
   ============================================= */

/* Контейнер */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Секция */
.section {
  padding: 5rem 0;
}

.section--sm {
  padding: 3rem 0;
}

/* Заголовок секции */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-family: var(--font-heading);
  position: relative;
  padding-bottom: 0.75rem;
}

/* Декоративная линия под заголовком секции */
.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--gradient-primary);
  border-radius: 2px;
}

/* Текстовые утилиты */
.text-primary { color: var(--primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Флекс-утилиты */
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }

/* Отображение */
.hidden { display: none !important; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* =============================================
   Кнопки
   ============================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-md);
  font-family: var(--font-main);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  white-space: nowrap;
  text-decoration: none;
  line-height: 1;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Основная кнопка */
.btn-primary {
  background: var(--gradient-primary);
  color: #fff;
  box-shadow: 0 4px 20px rgba(0, 212, 255, 0.25);
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(0, 212, 255, 0.4);
  color: #fff;
}

/* Вторичная кнопка */
.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--primary-glow);
  transform: translateY(-1px);
  color: var(--primary);
}

/* Призрачная кнопка */
.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1.5px solid var(--border);
}

.btn-ghost:hover:not(:disabled) {
  border-color: var(--primary);
  color: var(--primary);
}

/* Кнопка-иконка */
.btn-icon {
  padding: 0.6rem;
  border-radius: var(--radius-sm);
  width: 40px;
  height: 40px;
}

/* Размеры кнопок */
.btn-sm {
  padding: 0.5rem 1.25rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 1rem 2.5rem;
  font-size: 1.05rem;
}

/* =============================================
   Бейджи и теги
   ============================================= */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.8rem;
  border-radius: 100px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

/* Категории */
.badge-ai { background: rgba(0, 212, 255, 0.15); color: var(--cat-ai); }
.badge-robotics { background: rgba(123, 47, 255, 0.15); color: var(--cat-robotics); }
.badge-iot { background: rgba(0, 255, 136, 0.15); color: var(--cat-iot); }
.badge-vrar { background: rgba(255, 107, 53, 0.15); color: var(--cat-vrar); }
.badge-biotech { background: rgba(255, 45, 120, 0.15); color: var(--cat-biotech); }
.badge-drones { background: rgba(255, 204, 0, 0.15); color: var(--cat-drones); }
.badge-primary { background: var(--primary-glow); color: var(--primary); }

/* Тег */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.7rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  transition: all var(--transition);
}

.tag:hover {
  border-color: var(--primary);
  color: var(--primary);
  cursor: pointer;
}

/* =============================================
   Карточки
   ============================================= */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition);
}

.card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

/* Изображение карточки с плейсхолдером */
.card-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: linear-gradient(135deg, #1a1a28 0%, #12121c 100%);
}

/* Плейсхолдер изображения (если картинка не загрузилась) */
.card-image-placeholder {
  width: 100%;
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  background: linear-gradient(135deg, var(--bg-card) 0%, #1e1e30 100%);
}

.card-body {
  padding: 1.5rem;
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.card-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  line-height: 1.4;
  color: var(--text-primary);
  transition: color var(--transition);
}

.card-title:hover {
  color: var(--primary);
}

.card-preview {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border);
}

/* =============================================
   Сетки карточек
   ============================================= */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

/* =============================================
   Формы
   ============================================= */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  background: var(--bg-input);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-main);
  font-size: 0.95rem;
  transition: all var(--transition);
  appearance: none;
  outline: none;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--text-muted);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-select {
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%239090b0' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

/* Ошибка поля формы */
.form-error {
  display: none;
  font-size: 0.82rem;
  color: #ff4d6d;
  margin-top: 0.35rem;
}

.form-group.has-error .form-input,
.form-group.has-error .form-textarea {
  border-color: #ff4d6d;
  box-shadow: 0 0 0 3px rgba(255, 77, 109, 0.15);
}

.form-group.has-error .form-error {
  display: block;
}

/* =============================================
   Поиск
   ============================================= */
.search-wrapper {
  position: relative;
}

.search-input {
  padding-left: 2.75rem;
}

.search-icon {
  position: absolute;
  left: 0.9rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
  width: 18px;
  height: 18px;
}

/* =============================================
   Пагинация
   ============================================= */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 2rem 0;
}

.pagination-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  border: 1.5px solid var(--border);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
}

.pagination-btn:hover,
.pagination-btn.active {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-glow);
}

.pagination-btn.active {
  font-weight: 700;
}

/* =============================================
   Уведомления (toast)
   ============================================= */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 10000;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.toast {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 280px;
  max-width: 400px;
  animation: toastIn 0.35s ease;
}

.toast.toast-success { border-color: #00ff88; }
.toast.toast-error   { border-color: #ff4d6d; }
.toast.toast-info    { border-color: var(--primary); }

.toast-icon { font-size: 1.2rem; flex-shrink: 0; }
.toast-text { font-size: 0.9rem; color: var(--text-primary); }

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

/* =============================================
   Модальное окно
   ============================================= */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(6px);
  z-index: 9000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-slow);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  width: 100%;
  max-width: 480px;
  transform: translateY(20px);
  transition: transform var(--transition-slow);
}

.modal-overlay.active .modal {
  transform: translateY(0);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

.modal-title {
  font-size: 1.4rem;
  font-weight: 700;
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1.5rem;
  padding: 0.25rem;
  transition: color var(--transition);
  line-height: 1;
}

.modal-close:hover {
  color: var(--text-primary);
}

/* =============================================
   Загрузчик (спиннер)
   ============================================= */
.spinner {
  display: inline-block;
  width: 24px;
  height: 24px;
  border: 2.5px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

.spinner-lg {
  width: 48px;
  height: 48px;
  border-width: 4px;
}

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

/* Блок загрузки */
.loading-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 5rem 2rem;
  color: var(--text-secondary);
}

/* =============================================
   Пустое состояние
   ============================================= */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 5rem 2rem;
  text-align: center;
}

.empty-state-icon {
  font-size: 3.5rem;
  opacity: 0.3;
}

.empty-state-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.empty-state-text {
  font-size: 0.9rem;
  color: var(--text-muted);
  max-width: 300px;
}

/* =============================================
   Скелетон (загрузочные плейсхолдеры)
   ============================================= */
.skeleton {
  background: linear-gradient(90deg, var(--bg-card) 25%, #1e1e2e 50%, var(--bg-card) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-md);
}

@keyframes shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* =============================================
   Анимации появления при скролле
   ============================================= */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }

/* =============================================
   Разделитель
   ============================================= */
.divider {
  height: 1px;
  background: var(--border);
  margin: 2rem 0;
}

/* =============================================
   Подсветка совпадений при поиске
   ============================================= */
mark.highlight {
  background: rgba(0, 212, 255, 0.3);
  color: var(--primary);
  border-radius: 2px;
  padding: 0 2px;
}

/* =============================================
   Хлебные крошки (навигация)
   ============================================= */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--text-muted);
  transition: color var(--transition);
}

.breadcrumb a:hover {
  color: var(--primary);
}

.breadcrumb-sep {
  color: var(--border);
}

/* =============================================
   Адаптивность — планшет (≤ 1024px)
   ============================================= */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .section {
    padding: 3.5rem 0;
  }
}

/* =============================================
   Адаптивность — мобильные (≤ 768px)
   ============================================= */
@media (max-width: 768px) {
  :root {
    --container: 100%;
  }

  .container {
    padding: 0 1rem;
  }

  .grid-4,
  .grid-3,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 2.5rem 0;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .btn-lg {
    padding: 0.875rem 2rem;
    font-size: 1rem;
  }

  .modal {
    padding: 1.75rem;
    border-radius: var(--radius-lg);
  }

  .toast-container {
    bottom: 1rem;
    right: 1rem;
    left: 1rem;
  }

  .toast {
    min-width: auto;
    width: 100%;
  }
}