/* =======================================
   Переменные (CSS Variables)
   ======================================= */
:root {
  --primary: #3b82f6; /* Яркий синий для акцентов */
  --primary-dark: #1e40af; /* Тёмный синий для градиентов */
  --accent: #f1f5f9; /* Светлый текст (dark theme) */
  --bg: #0f172a; /* Тёмный фон */
  --card-bg: rgba(15, 23, 42, 0.8); /* Полупрозрачные карточки (dark) */
  --border: rgba(255, 255, 255, 0.15); /* Мягкие границы (dark) */
  --text: #ffffff; /* Белый текст */
  --subtext: rgba(255, 255, 255, 0.7); /* Светлый подтекст */
  --input-bg: rgba(255, 255, 255, 0.05); /* Фон инпутов (dark) */
  --shadow: 0 8px 32px rgba(31, 38, 135, 0.37);
  --radius: 16px;
  --transition: 0.3s ease;
  --font: 'Roboto', system-ui, -apple-system, sans-serif;
}

/* Light theme overrides */
body.light-theme {
  --accent: #0f172a; /* Тёмный текст (light theme) */
  --bg: #f1f5f9; /* Светлый фон */
  --card-bg: rgba(255, 255, 255, 0.8); /* Полупрозрачные карточки (light) */
  --border: rgba(0, 0, 0, 0.15); /* Мягкие границы (light) */
  --text: #0f172a; /* Тёмный текст */
  --subtext: rgba(0, 0, 0, 0.7); /* Тёмный подтекст */
  --input-bg: rgba(0, 0, 0, 0.05); /* Фон инпутов (light) */
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

/* =======================================
   Глобальные стили (Body и базовые)
   ======================================= */
html, body {
  overflow-x: hidden; /* Убирает горизонтальный скролл */
  width: 100%;
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

* {
  box-sizing: inherit;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--accent);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-size: cover;
  background-position: center;
  transition: background-color var(--transition), color var(--transition);
}

/* =======================================
   Шапка (Header)
   ======================================= */
.header {
  background: var(--bg);
  position: sticky;
  top: 0;
  width: 100%;
  z-index: 1000;
  padding: 16px 0;
  transition: background-color var(--transition), color var(--transition);
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: inherit;
}

.logo, .nav-link {
  transition: color var(--transition);
}


/* =======================================
   Основной контейнер (Main Container)
   ======================================= */
.main-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 64px 32px;
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* =======================================
   Контейнер загрузки (Download Container)
   ======================================= */
.download-container {
  margin-top: 10px;
  text-align: center;
}

.download-container a {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.9rem;
  color: var(--primary);
  text-decoration: none;
}

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

/* =======================================
   Карточки и секции (Card & Section)
   ======================================= */
.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 40px;
  margin-bottom: 48px;
  width: 100%;
  max-width: 480px;
  display: none;
  flex-direction: column;
  gap: 24px;
  backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  transition: background var(--transition), border var(--transition);
}

.section.active {
  display: flex;
}

/* =======================================
   Заголовки и формы (Headings & Forms)
   ======================================= */
h2 {
  margin: 0;
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
  text-align: center;
}

.input, select {
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  background: var(--input-bg);
  color: var(--text);
  transition: var(--transition);
  width: 100%;
  box-sizing: border-box;
}

.input:focus, select:focus {
  border-color: var(--primary);
  background: rgba(59, 130, 246, 0.1); /* Slight tint for focus */
}

.button {
  background: linear-gradient(to right, var(--primary), var(--primary-dark));
  color: #ffffff;
  border: none;
  border-radius: var(--radius);
  padding: 16px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.button:hover {
  transform: scale(1.02);
  opacity: 0.95;
}

.form-link {
  font-size: 1rem;
  color: var(--subtext);
  text-align: center;
}

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

.form-link a:hover {
  color: var(--text);
}

.label {
  font-size: 1rem;
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
}

/* =======================================
   Специальные элементы (Select, Preview, History, Code Inputs)
   ======================================= */
select {
  color: var(--text);
  background: var(--input-bg);
}

select option {
  background: var(--bg);
  color: var(--text);
  padding: 10px;
}

select option:hover {
  background: var(--primary);
}

.barcode-preview {
  margin-top: 24px;
  min-height: 80px;
  background: var(--input-bg);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text);
  transition: var(--transition);
  width: fit-content;
  max-width: 100%;
  height: auto;
  padding: 10px;
  box-sizing: border-box;
  margin-left: auto;
  margin-right: auto;
}

.barcode-preview img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
}

.history-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.history-card {
  background: var(--input-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  transition: var(--transition);
}

.history-card:hover {
  transform: scale(1.03);
}

.barcode-img {
  width: 100px;
  height: 50px;
  margin-bottom: 16px;
}

.history-info {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.history-date {
  font-size: 0.9rem;
  color: var(--subtext);
}

.code-inputs {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin: 20px 0;
}

.digit-input {
  width: 50px;
  height: 60px;
  text-align: center;
  font-size: 24px;
  border: 2px solid var(--primary);
  border-radius: 10px;
  background-color: var(--input-bg);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
  outline: none;
  color: var(--text);
}

.digit-input:focus {
  border-color: var(--primary-dark);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.5);
  transform: scale(1.05);
}

.digit-input:invalid {
  border-color: #ef4444;
}

#confirm p {
  text-align: center;
  margin: 0 auto;
  max-width: 80%;
  font-size: 1.1rem;
  color: var(--accent);
}

/* =======================================
   Футер (Footer)
   ======================================= */
.footer {
  position: relative;
  width: 100%;
  background: transparent;
  color: var(--subtext);
  padding: 32px 0;
  text-align: center;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  font-size: 0.9rem;
}

/* Theme toggle button */
#theme-toggle {
  position: absolute;
  bottom: 20px;
  right: 20px;
  background: transparent;
  color: var(--text);
  border-radius: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  z-index: 1000;
}

#theme-toggle:hover {
  transform: scale(1.1);
}

/* SVG иконки адаптируются по цвету через currentColor */
#theme-toggle svg {
  stroke: currentColor;
  width: 28px;
  height: 28px;
}

/* =======================================
   Медиа-запросы (Responsive Design)
   ======================================= */
@media (max-width: 768px) {
  .main-container {
    padding: 32px 16px;
    width: 100%;
    overflow: hidden;
  }
  .card {
    padding: 32px;
    max-width: 100%;
    box-sizing: border-box;
  }
  .history-list {
    grid-template-columns: 1fr;
    width: 100%;
  }
  .barcode-preview {
    max-width: 100%;
    overflow: hidden;
  }
  #theme-toggle {
    bottom: 10px;
    right: 10px;
    width: 40px;
    height: 40px;
  }
  #theme-toggle svg {
    width: 24px;
    height: 24px;
  }
  .footer {
    padding: 32px 16px;
    min-width: 100%;
  }
}