:root {
  --primary-color: #006A4E;       /* Primary Green */
  --secondary-color: #F42A41;     /* Secondary Red */
  --accent-gold: #D4AF37;         /* Accent Gold */
  --bg-color: #F8F9FA;            /* Soft light background */
  --surface-color: #FFFFFF;       /* Clean white card surface */
  --text-primary: #212529;        /* Primary text */
  --text-secondary: #6C757D;      /* Secondary text */
  --border-color: #E9ECEF;        /* Light clean borders */
  
  /* Alerts and accents */
  --success-bg: #E6F4EA;
  --success-color: #137333;
  --warning-bg: #FEF7E0;
  --warning-color: #B06000;
  --danger-bg: #FCE8E6;
  --danger-color: #C5221F;

  --border-radius-sm: 6px;
  --border-radius-md: 12px;
  --border-radius-lg: 16px;
  
  --box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04), 0 1px 3px rgba(0, 0, 0, 0.02);
  --box-shadow-hover: 0 12px 30px rgba(0, 106, 78, 0.08), 0 4px 10px rgba(0, 0, 0, 0.03);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
  font-family: 'Outfit', 'Hind Siliguri', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 1rem;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Scrollbar Customization */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-color);
}
::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: #94a3b8;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  color: var(--primary-color);
  letter-spacing: -0.02em;
  margin-bottom: 0.5em;
}

.text-white h1, .text-white h2, .text-white h3, .text-white h4, .text-white h5, .text-white h6,
.bg-success h1, .bg-success h2, .bg-success h3, .bg-success h4, .bg-success h5, .bg-success h6,
.bg-primary h1, .bg-primary h2, .bg-primary h3, .bg-primary h4, .bg-primary h5, .bg-primary h6,
.bg-danger h1, .bg-danger h2, .bg-danger h3, .bg-danger h4, .bg-danger h5, .bg-danger h6,
h1.text-white, h2.text-white, h3.text-white, h4.text-white, h5.text-white, h6.text-white {
  color: #ffffff !important;
}

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

/* Top Utility Bar */
.top-bar {
  background-color: #0b1a15;
  color: #e2e8f0;
  font-size: 0.85rem;
  padding: 8px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}
.top-bar a {
  color: #cbd5e1;
  text-decoration: none;
  margin-left: 15px;
  transition: var(--transition);
  font-weight: 500;
}
.top-bar a:hover {
  color: var(--accent-gold);
}
.top-bar span {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

/* Brand Header Area */
.brand-header {
  background-color: var(--surface-color);
  border-bottom: 4px solid var(--primary-color);
  padding: 24px 0;
}
.brand-header .container {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 20px;
}
.brand-title {
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  font-weight: 800;
  margin: 0;
  color: var(--primary-color);
  line-height: 1.2;
}
.brand-subtitle {
  font-size: clamp(0.85rem, 2.5vw, 1.1rem);
  font-weight: 500;
  margin: 4px 0 0 0;
  color: var(--text-secondary);
}

/* Main Navigation Bar */
.main-navbar {
  background-color: var(--primary-color) !important;
  padding: 0;
  box-shadow: var(--box-shadow);
  border-bottom: 3px solid var(--accent-gold);
}
.main-navbar .navbar-toggler {
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 8px 12px;
  border-radius: var(--border-radius-sm);
  transition: var(--transition);
}
.main-navbar .navbar-toggler:focus {
  box-shadow: 0 0 0 3px rgba(212, 175, 55, 0.4);
}
.main-navbar .nav-link {
  color: rgba(255, 255, 255, 0.9) !important;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 16px 20px !important;
  transition: var(--transition);
  border-bottom: 3px solid transparent;
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}
.main-navbar .nav-link:hover,
.main-navbar .nav-item.active .nav-link {
  background-color: rgba(255, 255, 255, 0.08);
  color: #ffffff !important;
  border-bottom-color: var(--accent-gold);
}
.main-navbar .dropdown-menu {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  padding: 8px;
  margin-top: 0;
}
.main-navbar .dropdown-item {
  color: var(--text-primary) !important;
  font-weight: 500;
  padding: 10px 16px;
  border-radius: var(--border-radius-sm);
  transition: var(--transition);
}
.main-navbar .dropdown-item:hover {
  background-color: rgba(0, 106, 78, 0.05);
  color: var(--primary-color) !important;
  transform: translateX(4px);
}

/* Premium Card Layouts */
.card {
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  background-color: var(--surface-color);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}
.card:hover {
  box-shadow: var(--box-shadow-hover);
}

.hover-shadow {
  transition: var(--transition);
}
.hover-shadow:hover {
  transform: translateY(-4px);
  box-shadow: var(--box-shadow-hover);
}

/* Sidebar Styling */
.sidebar-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 24px;
  margin-bottom: 24px;
  box-shadow: var(--box-shadow);
}
.sidebar-title {
  font-size: 1.1rem;
  font-weight: 700;
  border-bottom: 2px solid var(--primary-color);
  padding-bottom: 10px;
  margin-bottom: 18px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--primary-color);
}

/* Table of Contents Redesign */
.section-header {
  border: 1px solid rgba(0, 106, 78, 0.15);
  border-radius: 30px;
  background-color: rgba(0, 106, 78, 0.05);
  padding: 8px 24px;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary-color);
  width: fit-content;
  margin-top: 32px;
  margin-bottom: 18px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.02);
}

.article-toc-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 20px;
  margin-bottom: 16px;
  transition: var(--transition);
  box-shadow: var(--box-shadow);
}
.article-toc-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--box-shadow-hover);
}

.article-toc-cover {
  width: 80px;
  height: 110px;
  object-fit: cover;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  box-shadow: 0 4px 8px rgba(0,0,0,0.06);
}

.article-toc-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 6px;
  line-height: 1.4;
}
.article-toc-title a {
  color: var(--text-primary);
  text-decoration: none;
}
.article-toc-title a:hover {
  color: var(--primary-color);
  text-decoration: underline;
}

.article-toc-author {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-weight: 500;
  margin-bottom: 8px;
}

.article-toc-stats {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 15px;
}
.article-toc-stats i {
  color: var(--primary-color);
}

.article-toc-doi {
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  margin-bottom: 10px;
}

.article-toc-doi-badge {
  background-color: var(--accent-gold);
  color: #000;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.75rem;
  margin-right: 8px;
  text-transform: uppercase;
}

.article-toc-page-range {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary-color);
  background-color: rgba(0, 106, 78, 0.05);
  padding: 4px 12px;
  border-radius: 20px;
}

/* Authentication Cards */
.auth-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.06);
  overflow: hidden;
  max-width: 520px;
  margin: 50px auto;
}
.auth-header {
  background-color: var(--primary-color);
  color: #fff;
  padding: 30px;
  text-align: center;
  border-bottom: 4px solid var(--accent-gold);
}
.auth-body {
  padding: 32px;
}

/* Form Controls & Inputs */
.form-label {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.9rem;
  margin-bottom: 6px;
}
.form-control, .form-select {
  border: 1px solid #cbd5e1;
  padding: 10px 14px;
  border-radius: var(--border-radius-sm);
  font-size: 0.95rem;
  color: var(--text-primary);
  background-color: var(--surface-color);
  transition: var(--transition);
}
.form-control:focus, .form-select:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(0, 106, 78, 0.15);
}

/* Custom Buttons */
.btn {
  padding: 10px 20px;
  font-weight: 600;
  border-radius: var(--border-radius-sm);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}
.btn-sm {
  padding: 6px 14px;
  font-size: 0.85rem;
}
.btn-primary {
  background-color: var(--primary-color);
  border-color: var(--primary-color);
  color: #ffffff;
}
.btn-primary:hover, .btn-primary:focus {
  background-color: #00503a;
  border-color: #00503a;
  color: #ffffff;
  transform: translateY(-1px);
}
.btn-secondary {
  background-color: var(--accent-gold);
  border-color: var(--accent-gold);
  color: #212529;
}
.btn-secondary:hover, .btn-secondary:focus {
  background-color: #c49f31;
  border-color: #c49f31;
  color: #212529;
  transform: translateY(-1px);
}
.btn-outline-primary {
  color: var(--primary-color);
  border-color: var(--primary-color);
}
.btn-outline-primary:hover {
  background-color: var(--primary-color);
  color: #ffffff;
}
.btn-danger {
  background-color: var(--secondary-color);
  border-color: var(--secondary-color);
  color: #ffffff;
}
.btn-danger:hover {
  background-color: #d11d32;
  border-color: #d11d32;
}

/* Audio Player Container */
.audio-player-container {
  background-color: #f1f5f9;
  border-radius: var(--border-radius-md);
  padding: 20px;
  border-left: 4px solid var(--accent-gold);
  margin: 24px 0;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.03);
}

/* Footer Styling */
.main-footer {
  background-color: #08120e;
  color: #94a3b8;
  font-size: 0.9rem;
  padding: 60px 0 30px;
  margin-top: 60px;
  border-top: 5px solid var(--accent-gold);
}
.main-footer h5 {
  color: #ffffff;
  font-weight: 700;
  margin-bottom: 24px;
  font-size: 1.1rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  position: relative;
  padding-bottom: 8px;
}
.main-footer h5::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 40px;
  height: 2px;
  background-color: var(--accent-gold);
}
.main-footer a {
  color: #94a3b8;
  text-decoration: none;
  transition: var(--transition);
}
.main-footer a:hover {
  color: #ffffff;
  padding-left: 4px;
}
.main-footer .text-muted-footer {
  color: #94a3b8 !important;
  line-height: 1.7;
}

/* Responsive Overrides (Mobile-first design) */
@media (max-width: 991.98px) {
  /* Mobile Navigation Slide Down Panel */
  .main-navbar .navbar-collapse {
    background-color: var(--primary-color);
    padding: 15px;
    border-radius: 0 0 var(--border-radius-md) var(--border-radius-md);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
  }
  .main-navbar .nav-link {
    padding: 12px 10px !important;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  .main-navbar .nav-link:hover {
    border-bottom-color: var(--accent-gold);
  }
  .brand-header .container {
    flex-direction: column;
    text-align: center;
    gap: 10px;
  }
  .top-bar .container {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }
  .top-bar a {
    margin: 0 8px;
  }
}

/* Custom Grid Adjustments */
img {
  max-width: 100%;
  height: auto;
}

/* Line clamping for cards */
.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.line-clamp-3 {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Admin Sidebar & Overlays */
.admin-wrapper {
  display: flex;
  min-height: 100vh;
}
.admin-sidebar {
  width: 260px;
  background-color: #0b1e18;
  color: #fff;
  transition: var(--transition);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  flex-shrink: 0;
}
.admin-sidebar::-webkit-scrollbar {
  width: 4px;
}
.admin-sidebar::-webkit-scrollbar-thumb {
  background-color: rgba(255, 255, 255, 0.15);
  border-radius: 4px;
}
.admin-sidebar .sidebar-brand {
  padding: 24px 20px;
  font-size: 1.25rem;
  font-weight: 700;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  background: rgba(0,0,0,0.15);
  color: var(--accent-gold);
}
.admin-sidebar .nav-link {
  color: #94a3b8;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-left: 4px solid transparent;
  transition: var(--transition);
}
.admin-sidebar .nav-link:hover,
.admin-sidebar .nav-link.active {
  background: rgba(255, 255, 255, 0.03);
  color: #ffffff;
  border-left-color: var(--accent-gold);
}
.admin-content {
  flex-grow: 1;
  background-color: #f1f5f9;
  padding: 24px;
  overflow-x: auto;
}
.admin-navbar-top {
  background: #ffffff;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Lightbox Styling */
.modal-content.bg-dark {
  background-color: #090d16 !important;
}

.cursor-pointer {
  cursor: pointer;
}
.hover-opacity-100 {
  opacity: 0;
  transition: var(--transition);
}
.card:hover .hover-opacity-100 {
  opacity: 1;
}

/* Badges */
.badge {
  font-weight: 600;
  padding: 5px 10px;
  border-radius: 4px;
}
.bg-primary-subtle {
  background-color: rgba(0, 106, 78, 0.1) !important;
  color: var(--primary-color) !important;
}

/* Breadcrumbs customization */
.breadcrumb-item a {
  color: var(--primary-color);
  font-weight: 500;
}
.breadcrumb-item.active {
  color: var(--text-secondary);
}