:root {
  --bg-gradient: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
  --glass-bg: rgba(16, 18, 27, 0.4);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-hover: rgba(255, 255, 255, 0.15);
  --accent-glow: 0 0 20px rgba(255, 0, 128, 0.6);
  --accent-color: #ff0080;
  --accent-color-hover: #ff4d94;
  --text-main: #ffffff;
  --text-muted: #a0a5b1;
  --panel-radius: 20px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background: var(--bg-gradient);
  background-size: 400% 400%;
  animation: gradientBG 15s ease infinite;
  color: var(--text-main);
  height: 100vh;
  display: flex;
  overflow: hidden;
}

@keyframes gradientBG {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* Glassmorphism Classes */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--panel-radius);
}

/* Layout */
#app {
  display: flex;
  width: 100%;
  height: 100%;
  padding: 20px;
  gap: 20px;
}

/* Sidebar */
aside {
  width: 320px;
  display: flex;
  flex-direction: column;
  padding: 24px;
  gap: 24px;
}

.logo-container {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-container h1 {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(90deg, #a8c0ff 0%, #3f2b96 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.upload-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.file-drop-area {
  border: 2px dashed var(--glass-border);
  border-radius: 12px;
  padding: 30px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
}

.file-drop-area:hover {
  border-color: var(--accent-color);
  background: var(--glass-hover);
}

.btn {
  background: var(--accent-color);
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn:hover {
  background: var(--accent-color-hover);
  box-shadow: var(--accent-glow);
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

/* Papers List */
.papers-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  overflow-y: auto;
  flex-grow: 1;
}

.paper-item {
  padding: 12px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: 8px;
  border-left: 3px solid var(--accent-color);
  font-size: 0.9rem;
}

/* Main Content */
main {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  padding: 24px;
  position: relative;
  overflow: hidden;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--glass-border);
  padding-bottom: 10px;
}

.tab {
  background: transparent;
  color: var(--text-muted);
  border: none;
  padding: 10px 20px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border-radius: 8px;
  transition: all 0.3s ease;
}

.tab:hover {
  color: var(--text-main);
  background: var(--glass-hover);
}

.tab.active {
  color: #fff;
  background: var(--glass-bg);
  box-shadow: inset 0 -2px 0 var(--accent-color);
}

.tab-content {
  display: none;
  flex-grow: 1;
  flex-direction: column;
  animation: fadeIn 0.4s ease forwards;
  overflow-y: auto;
}

.tab-content.active {
  display: flex;
}

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

/* Chat Tab */
.chat-window {
  flex-grow: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-right: 10px;
  margin-bottom: 20px;
}

.message {
  max-width: 80%;
  padding: 16px;
  border-radius: 12px;
  line-height: 1.5;
  font-size: 0.95rem;
}

.message.user {
  align-self: flex-end;
  background: var(--accent-color);
  border-bottom-right-radius: 2px;
}

.message.assistant {
  align-self: flex-start;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-bottom-left-radius: 2px;
}

.chat-input-container {
  display: flex;
  gap: 12px;
  flex-shrink: 0;
}

.chat-input-container input {
  flex-grow: 1;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: var(--text-main);
  padding: 16px;
  border-radius: 12px;
  font-size: 1rem;
  outline: none;
  transition: border-color 0.3s ease;
}

.chat-input-container input:focus {
  border-color: var(--accent-color);
}

/* Intelligence Dashboard */
.grid-dashboard {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.action-card {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  text-align: center;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: all 0.3s ease;
}

.action-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-color);
  background: var(--glass-hover);
}

.action-card i {
  font-size: 2rem;
  color: var(--accent-color);
}

/* Dynamic Content Areas */
.dynamic-result {
  margin-top: 24px;
  padding: 24px;
  line-height: 1.6;
  overflow-y: auto;
  max-height: 60vh;
}

.dynamic-result h3 {
  margin-bottom: 16px;
  color: #fff;
}

/* Loading Overlay */
#loader {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(4px);
  display: none;
  justify-content: center;
  align-items: center;
  border-radius: var(--panel-radius);
  z-index: 100;
  flex-direction: column;
  gap: 16px;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--glass-border);
  border-top-color: var(--accent-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  100% { transform: rotate(360deg); }
}

/* Citation Highlighting */
.citation {
  background-color: rgba(108, 92, 231, 0.2);
  color: #a8c0ff;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85em;
  cursor: help;
}

/* Summaries Tab */
.summary-selector {
  width: 100%;
  padding: 12px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: var(--text-main);
  border-radius: 8px;
  margin-bottom: 16px;
  font-size: 1rem;
}
.summary-selector option {
  background: var(--bg-gradient);
  color: var(--text-main);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  body {
    height: auto;
    overflow: auto;
  }
  
  #app {
    flex-direction: column;
    height: auto;
    padding: 10px;
  }
  
  aside {
    width: 100%;
  }
  
  main {
    height: auto;
    overflow: visible;
  }
  
  .tab-content {
    overflow-y: visible;
  }
  
  .grid-dashboard {
    grid-template-columns: 1fr;
  }
  
  .tabs {
    flex-wrap: wrap;
  }
}