/* ==================== COURSE MATERIALS PAGE STYLES ==================== */

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

body {
  font-family: 'Inter', sans-serif;
  background: #f8f9ff;
  color: #0b1c30;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Top App Bar */
.top-app-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid #c3c6d1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 16px;
  height: 60px;
  width: 100%;
}

@media (min-width: 768px) {
  .top-app-bar {
    height: 64px;
    padding: 0 24px;
  }
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  width: 36px;
  height: 36px;
  border-radius: 12px;
  background: #003366;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

@media (min-width: 768px) {
  .logo-icon {
    width: 40px;
    height: 40px;
  }
}

.logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  padding: 6px;
}

.logo-text {
  font-size: 16px;
  font-weight: 800;
  color: #001e40;
}

@media (min-width: 768px) {
  .logo-text {
    font-size: 18px;
  }
}

.icon-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
  color: #001e40;
}

.icon-btn:active {
  transform: scale(0.95);
}

/* Main Content */
.main-content {
  flex: 1;
  padding: 16px;
  padding-bottom: 80px;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

@media (min-width: 768px) {
  .main-content {
    padding: 24px;
  }
}

/* Hero Section */
.hero-section .bg-gradient-to-r {
  background: linear-gradient(135deg, #001e40, #003366);
}

/* Search Input */
.search-input {
  transition: all 0.2s ease;
}

.search-input:focus {
  outline: none;
  border-color: #003366;
  box-shadow: 0 0 0 3px rgba(0, 51, 102, 0.1);
}

/* Filter Section */
.filter-section select {
  cursor: pointer;
  transition: all 0.2s;
}

.filter-section select:focus {
  outline: none;
  border-color: #003366;
}

/* Category Tabs */
.category-tab {
  transition: all 0.2s ease;
  white-space: nowrap;
  cursor: pointer;
}

.category-tab.active {
  background: #003366;
  color: white;
  box-shadow: 0 2px 8px rgba(0, 51, 102, 0.2);
}

.category-tab:active {
  transform: scale(0.96);
}

/* Horizontal Scroll */
.horizontal-scroll {
  overflow-x: auto;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.horizontal-scroll::-webkit-scrollbar {
  height: 4px;
}

.horizontal-scroll::-webkit-scrollbar-track {
  background: #e5eeff;
  border-radius: 10px;
}

.horizontal-scroll::-webkit-scrollbar-thumb {
  background: #003366;
  border-radius: 10px;
}

/* Material Cards */
.material-card {
  flex: 0 0 auto;
  width: 300px;
  transition: all 0.2s ease;
}

@media (max-width: 640px) {
  .material-card {
    width: 260px;
  }
}

.material-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

/* Download Button */
.download-btn {
  transition: all 0.2s ease;
  cursor: pointer;
}

.download-btn:active {
  transform: scale(0.96);
}

/* Bottom Navigation */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: space-around;
  align-items: center;
  height: 60px;
  padding: 0 12px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  z-index: 100;
  border-top: 1px solid #c3c6d1;
  box-shadow: 0 -4px 12px rgba(0, 51, 102, 0.05);
}

@media (min-width: 768px) {
  .bottom-nav {
    height: 64px;
    padding: 0 20px;
  }
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  color: #43474f;
  transition: all 0.2s;
  gap: 2px;
  flex: 1;
  padding: 8px 0;
}

.nav-item.active {
  color: #001e40;
}

.nav-item.active .material-symbols-outlined {
  font-variation-settings: 'FILL' 1;
}

.nav-label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.03em;
}

@media (min-width: 768px) {
  .nav-label {
    font-size: 11px;
  }
}

.nav-item:active {
  transform: scale(0.95);
}

.nav-item .material-symbols-outlined {
  font-size: 22px;
}

@media (min-width: 768px) {
  .nav-item .material-symbols-outlined {
    font-size: 24px;
  }
}

/* Utility Classes */
.hide-scrollbar::-webkit-scrollbar {
  display: none;
}

.hide-scrollbar {
  -ms-overflow-style: none;
  scrollbar-width: none;
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.3s ease-out;
}