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

:root {
  --primary-color: #0c2b4e;      /* Deep Hydrology Navy */
  --primary-light: #16467a;      /* Lighter Navy */
  --accent-color: #0076f7;       /* Wave Blue */
  --accent-hover: #005ec7;       /* Deep Wave Blue */
  --bg-color: #f1f5f9;           /* Soft Slate Blue Background */
  --card-bg: #ffffff;            /* Pure White */
  --text-dark: #0f172a;          /* Slate Dark Text */
  --text-muted: #64748b;         /* Slate Muted Text */
  --border-color: #e2e8f0;       /* Soft Gray Border */
  --cyan-accent: #06b6d4;        /* Cyan Highlight */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 20px -2px rgba(12, 43, 78, 0.08);
  --shadow-lg: 0 10px 30px -5px rgba(12, 43, 78, 0.12);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --font-heading: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-color);
  color: var(--text-dark);
  line-height: 1.6;
  overflow-x: hidden;
}

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

/* Layout structure */
.app-container {
  display: flex;
  min-height: 100vh;
}

/* Sidebar navigation */
.sidebar {
  width: 280px;
  background-color: var(--primary-color);
  color: #ffffff;
  padding: 30px 20px;
  display: flex;
  flex-direction: column;
  position: fixed;
  height: 100vh;
  left: 0;
  top: 0;
  z-index: 100;
  box-shadow: 4px 0 15px rgba(0, 0, 0, 0.1);
}

.logo-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding-bottom: 30px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: 25px;
}

.logo-img {
  width: 140px;
  height: auto;
  margin-bottom: 15px;
  filter: brightness(0) invert(1); /* Force APRH logo white */
}

.logo-title {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.5rem;
  letter-spacing: 1px;
  background: linear-gradient(135deg, #ffffff 60%, #a5f3fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-subtitle {
  font-size: 0.75rem;
  color: #94a3b8;
  margin-top: 5px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.nav-menu {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.nav-item {
  display: flex;
  align-items: center;
  padding: 14px 18px;
  color: #cbd5e1;
  text-decoration: none;
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: 1rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}

.nav-item i {
  margin-right: 12px;
  font-size: 1.15rem;
  width: 20px;
  text-align: center;
}

.nav-item:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.05);
}

.nav-item.active {
  color: #ffffff;
  background-color: var(--accent-color);
  box-shadow: 0 4px 14px rgba(0, 118, 247, 0.3);
}

.sidebar-footer {
  margin-top: auto;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.75rem;
  color: #94a3b8;
  text-align: center;
}

/* Main Content Area */
.main-content {
  flex: 1;
  margin-left: 280px;
  padding: 40px;
  min-height: 100vh;
}

/* Top bar and header */
.header-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  background: var(--card-bg);
  padding: 24px 32px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.page-title-group h1 {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.8rem;
  color: var(--primary-color);
}

.page-title-group p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Tab panes */
.tab-pane {
  display: none;
  animation: fadeIn 0.4s ease;
}

.tab-pane.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- HOME PAGE TAB --- */
.hero-card {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
  color: #ffffff;
  padding: 50px;
  border-radius: var(--radius-lg);
  margin-bottom: 35px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.hero-card::after {
  content: '';
  position: absolute;
  right: -50px;
  bottom: -50px;
  width: 250px;
  height: 250px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 118, 247, 0.2) 0%, rgba(0, 0, 0, 0) 70%);
}

.hero-tag {
  display: inline-block;
  background: rgba(255, 255, 255, 0.1);
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 20px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-card h2 {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 15px;
}

.hero-card p {
  color: #94a3b8;
  max-width: 700px;
  font-size: 1.1rem;
}

.grid-dashboard {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 25px;
  margin-bottom: 35px;
}

.stat-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 30px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  gap: 20px;
  cursor: pointer;
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-color);
}

.stat-icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--bg-color);
  color: var(--accent-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  transition: var(--transition);
}

.stat-card:hover .stat-icon {
  background: var(--accent-color);
  color: #ffffff;
}

.stat-info h3 {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary-color);
}

.stat-info p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.presentation-section {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 40px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.presentation-section h3 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  margin-bottom: 20px;
  color: var(--primary-color);
}

.presentation-section p {
  margin-bottom: 15px;
  color: #334155;
  font-size: 1rem;
  text-align: justify;
}

/* --- ARTICLES PAGE TAB --- */
.controls-bar {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 24px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  margin-bottom: 30px;
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  align-items: center;
}

.search-box {
  flex: 1;
  min-width: 300px;
  position: relative;
}

.search-box i {
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 1.1rem;
}

.search-input {
  width: 100%;
  padding: 14px 18px 14px 48px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: 0.95rem;
  background-color: var(--bg-color);
  color: var(--text-dark);
  transition: var(--transition);
}

.search-input:focus {
  outline: none;
  border-color: var(--accent-color);
  background-color: #ffffff;
  box-shadow: 0 0 0 3px rgba(0, 118, 247, 0.15);
}

.filter-select {
  padding: 14px 20px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: 0.95rem;
  background-color: var(--bg-color);
  color: var(--text-dark);
  cursor: pointer;
  transition: var(--transition);
  min-width: 200px;
}

.filter-select:focus {
  outline: none;
  border-color: var(--accent-color);
  background-color: #ffffff;
}

.clear-btn {
  padding: 14px 24px;
  background-color: #ef4444;
  color: #ffffff;
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-heading);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.clear-btn:hover {
  background-color: #dc2626;
}

.results-info {
  margin-bottom: 20px;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.papers-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* Paper Card design */
.paper-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px 30px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.paper-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 5px;
  background-color: var(--primary-light);
  transition: var(--transition);
}

.paper-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.paper-card:hover::before {
  background-color: var(--accent-color);
}

.paper-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 12px;
  gap: 15px;
}

.paper-id-badge {
  background: var(--bg-color);
  color: var(--primary-color);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-family: var(--font-heading);
  font-size: 0.9rem;
  border: 1px solid var(--border-color);
  white-space: nowrap;
}

.paper-theme-tag {
  font-size: 0.8rem;
  color: var(--accent-color);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  text-align: right;
  max-width: 400px;
}

.paper-title {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 8px;
  line-height: 1.35;
}

.paper-authors {
  font-size: 0.95rem;
  color: #475569;
  font-weight: 500;
  margin-bottom: 20px;
}

.paper-abstract-toggle {
  background: none;
  border: none;
  color: var(--accent-color);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.paper-abstract-toggle:hover {
  color: var(--accent-hover);
}

.paper-abstract-toggle i {
  transition: transform 0.3s ease;
}

.paper-abstract-toggle.expanded i {
  transform: rotate(180deg);
}

.paper-abstract-box {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0, 1, 0, 1);
  background: #f8fafc;
  border-radius: var(--radius-md);
  margin-top: 15px;
  border: 0 solid transparent;
}

.paper-abstract-box.open {
  max-height: 2000px;
  padding: 20px;
  border: 1px dashed var(--border-color);
  transition: max-height 0.4s cubic-bezier(1, 0, 1, 0);
}

.paper-abstract-box h4 {
  font-family: var(--font-heading);
  color: var(--primary-color);
  font-size: 0.95rem;
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.paper-abstract-text {
  font-size: 0.9rem;
  color: #334155;
  text-align: justify;
}

.paper-keywords-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 15px;
}

.paper-keyword-tag {
  background: #e2e8f0;
  color: #334155;
  font-size: 0.75rem;
  padding: 4px 10px;
  border-radius: 12px;
  cursor: pointer;
  transition: var(--transition);
}

.paper-keyword-tag:hover {
  background-color: var(--accent-color);
  color: #ffffff;
}

.paper-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: 15px;
  border-top: 1px solid var(--border-color);
  padding-top: 15px;
}

.pdf-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background-color: var(--accent-color);
  color: #ffffff;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  text-decoration: none;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9rem;
  box-shadow: 0 4px 10px rgba(0, 118, 247, 0.2);
  transition: var(--transition);
  border: none;
  cursor: pointer;
}

.pdf-btn:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 15px rgba(0, 118, 247, 0.35);
}

/* --- AUTHORS TAB --- */
.az-container {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 25px;
}

.az-index {
  display: flex;
  flex-direction: column;
  gap: 5px;
  position: sticky;
  top: 120px;
  height: fit-content;
}

.az-letter {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 45px;
  height: 45px;
  border-radius: 50%;
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--primary-color);
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.az-letter:hover, .az-letter.active {
  background: var(--accent-color);
  color: #ffffff;
  border-color: var(--accent-color);
}

.authors-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.author-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 20px 24px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: var(--transition);
}

.author-card:hover {
  border-color: var(--accent-color);
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

.author-name {
  font-family: var(--font-heading);
  font-weight: 600;
  color: var(--primary-color);
  font-size: 1.05rem;
}

.author-papers-count {
  background: var(--bg-color);
  color: var(--text-muted);
  width: 30px;
  height: 30px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  border: 1px solid var(--border-color);
}

.author-card:hover .author-papers-count {
  background: var(--accent-color);
  color: #ffffff;
  border-color: var(--accent-color);
}

/* --- KEYWORDS TAB --- */
.keywords-container {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 40px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.keyword-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.cloud-tag {
  background: var(--bg-color);
  color: var(--primary-color);
  padding: 8px 16px;
  border-radius: 20px;
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid var(--border-color);
}

.cloud-tag:hover {
  background: var(--accent-color);
  color: #ffffff;
  border-color: var(--accent-color);
  transform: scale(1.05);
}

.cloud-tag.size-sm { font-size: 0.85rem; opacity: 0.8; }
.cloud-tag.size-md { font-size: 1rem; font-weight: 600; }
.cloud-tag.size-lg { font-size: 1.2rem; font-weight: 700; border-width: 2px; }

/* --- INFO TAB --- */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 25px;
}

.info-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 30px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.info-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-color);
}

.info-icon-wrapper {
  width: 50px;
  height: 50px;
  border-radius: 12px;
  background-color: var(--bg-color);
  color: var(--accent-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 20px;
  transition: var(--transition);
}

.info-card:hover .info-icon-wrapper {
  background-color: var(--accent-color);
  color: #ffffff;
}

.info-card h3 {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  color: var(--primary-color);
  margin-bottom: 10px;
}

.info-card p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 20px;
  flex-grow: 1;
}

/* Responsive styles for mobile */
@media (max-width: 1024px) {
  .app-container {
    flex-direction: column;
  }
  
  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
    padding: 20px;
  }
  
  .logo-container {
    padding-bottom: 15px;
    margin-bottom: 15px;
  }
  
  .nav-menu {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: 5px;
  }
  
  .nav-item {
    padding: 10px 14px;
    font-size: 0.9rem;
  }
  
  .main-content {
    margin-left: 0;
    padding: 20px;
  }
  
  .header-bar {
    padding: 20px;
  }
}

@media (max-width: 768px) {
  .hero-card {
    padding: 30px;
  }
  
  .hero-card h2 {
    font-size: 1.8rem;
  }
  
  .az-container {
    grid-template-columns: 1fr;
  }
  
  .az-index {
    flex-direction: row;
    flex-wrap: wrap;
    position: relative;
    top: 0;
    margin-bottom: 20px;
    justify-content: center;
  }
  
  .az-letter {
    width: 35px;
    height: 35px;
    font-size: 0.85rem;
  }
}