/* بارگذاری فونت دلخواه */
@font-face {
  font-family: 'Avenir Next Ultra Light';
  src: url('fonts/avenir-next-ultra-light.ttf') format('truetype');
  font-weight: normal;
  font-style: normal;
}

/* تنظیمات پایه */
body {
  font-family: 'Avenir Next Ultra Light', sans-serif;
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  color: white;
  direction: ltr;
  overflow: hidden;
  background-color: #000;
}

.container {
  display: flex;
  min-height: 100vh;
  position: relative;
  align-items: flex-start;
}

/* پس‌زمینه اسلایدر */
.background-slider {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
}

.background-slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  opacity: 0;
  transition: opacity 2s ease-in-out;
}

.background-slide.active {
  opacity: 1;
}

/* لایه کنترل اسلایدر */
.slider-controller {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 5;
  cursor: pointer;
}

/* سایدبار */
.sidebar {
  width: 250px;
  padding: 1em;
  text-align: left;
  z-index: 1;
}

.sidebar h1 {
  margin-bottom: 0.5em;
  cursor: pointer;
}

.sidebar nav ul {
  list-style: none;
  padding: 0;
}

.sidebar nav ul li {
  margin-bottom: 0.2em;
}

.sidebar nav ul li a {
  color: white;
  text-decoration: none;
  display: block;
  padding: 0.3em;
  border-radius: 4px;
  transition: background-color 0.3s ease;
  cursor: pointer;
}

.sidebar nav ul li a:hover {
  background-color: rgba(255, 255, 255, 0.2);
}

/* محتوای اصلی */
.content {
  flex: 1;
  padding: 2em;
  z-index: 1;
  text-align: left;
}

/* مخفی‌سازی اولیه بخش‌ها */
.hidden {
  display: none;
}

#introduction,
#contact {
  max-width: 800px;
  margin: 0 auto 2em auto;
  padding: 1em;
  border-radius: 8px;
  background-color: transparent;
}

/* واکنش‌گرایی برای موبایل */
@media (max-width: 768px) {
  .container {
    flex-direction: column;
    align-items: stretch;
  }

  .sidebar {
    order: 1;
    width: 100%;
    padding: 1em;
    text-align: center;
  }

  .background-slider {
    order: 2;
    height: 60vh;
    margin-top: 120px;
  }

  .sidebar h1 {
    font-size: 2em;
    margin-bottom: 10px;
  }

  .sidebar nav ul {
    display: flex;
    justify-content: center;
    list-style: none;
    padding: 0;
  }

  .sidebar nav ul li {
    margin: 0 10px;
  }

  .sidebar nav ul li a {
    color: white;
    text-decoration: none;
    padding: 5px 10px;
    border-radius: 4px;
    transition: background-color 0.3s ease;
    cursor: pointer;
  }

  .sidebar nav ul li a:hover {
    background-color: rgba(255, 255, 255, 0.2);
  }

  .content {
    display: none;
  }
}