frontend/src/index.css

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

:root {
  --canvas-bg: #0b0c10;
  --primary-surface: #121318;
  --secondary-surface: #1a1c23;
  --active-state: #242731;
  --muted-text: #8e92a3;
  --glow-warm: #ff6b4a;
  --glow-cool: #3a6dff;
  --btn-gradient: linear-gradient(135deg, #af57ff, #6e85ff);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Inter', sans-serif;
}

body {
  background-color: var(--canvas-bg);
  color: #ffffff;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

/* Ambient Background Glows */
.ambient-glow {
  position: fixed;
  width: 60vw;
  height: 60vw;
  filter: blur(120px);
  opacity: 0.15;
  pointer-events: none;
  z-index: 0;
}

.glow-left {
  top: -10%;
  left: -10%;
  background: var(--glow-warm);
}

.glow-right {
  bottom: -10%;
  right: -10%;
  background: var(--glow-cool);
}

/* Main Layout */
.app-container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 800px;
  height: 90vh;
  display: flex;
  flex-direction: column;
  padding: 20px;
}

/* Chat History */
.chat-window {
  flex: 1;
  overflow-y: auto;
  padding: 20px 10px;
  display: flex;
  flex-direction: column;
  gap: 32px;
  scrollbar-width: none;
}

.chat-window::-webkit-scrollbar { display: none; }

.message {
  max-width: 85%;
  line-height: 1.6;
  font-size: 15px;
}

.user-message {
  align-self: flex-end;
  text-align: right;
  color: #fff;
}

.ai-message {
  align-self: flex-start;
  color: #e2e2e2;
}

/* Interaction Hub (Input Area) */
.interaction-hub {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.input-pill {
  background: var(--primary-surface);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 24px;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.input-pill input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: #fff;
  font-size: 16px;
}

.input-pill input::placeholder {
  color: var(--muted-text);
}

/* Mode Switchers */
.mode-tabs {
  display: flex;
  gap: 8px;
  background: rgba(0, 0, 0, 0.2);
  padding: 4px;
  border-radius: 20px;
}

.tab {
  padding: 6px 14px;
  border-radius: 16px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  color: var(--muted-text);
  transition: all 0.2s ease;
}

.tab.active {
  background: var(--active-state);
  color: #fff;
}

/* Dropdown Menu (Secondary Surface) */
.dropdown-menu {
  background: var(--secondary-surface);
  border-radius: 16px;
  padding: 8px;
  width: 180px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 10px 25px rgba(0,0,0,0.5);
  margin-left: 20px;
  animation: slideUp 0.2s ease-out;
}

.menu-item {
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--muted-text);
  cursor: pointer;
}

.menu-item:hover {
  background: var(--active-state);
  color: #fff;
}

/* Action Buttons */
.send-btn {
  width: 40px;
  height: 40px;
  border-radius: 20px;
  background: var(--btn-gradient);
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: transform 0.2s;
}

.send-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 15px rgba(175, 87, 255, 0.4);
}

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

/* RAG Source styling */
.sources {
  margin-top: 12px;
  display: flex;
  gap: 10px;
  flex-wrap: wrap
}

.source-pill {
  font-size: 11px;
  background: rgba(255,255,255,0.05);
  padding: 4px 10px;
  border-radius: 6px;
  border: 1px solid rgba(255,255,255,0.1);
  color: var(--muted-text);
}
.skeleton-line {
  height: 12px;
  border-radius: 6px;
  background: linear-gradient(90deg, #1e1e2e 25%, #2a2a3e 50%, #1e1e2e 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  margin-bottom: 10px;
}
.skeleton-line.wide   { width: 90%; }
.skeleton-line.medium { width: 65%; }
.skeleton-line.narrow { width: 40%; }

@keyframes shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}
.skeleton-card {
  width: 60%;
  min-width: 300px;
  padding: 8px 0;
}
.meta-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 10px 0 8px;
}

.strategy-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.strategy-bm25         { background: rgba(59,130,246,0.15); color: #60a5fa; }
.strategy-dense        { background: rgba(168,85,247,0.15); color: #c084fc; }
.strategy-hybrid       { background: rgba(20,184,166,0.15); color: #2dd4bf; }
.strategy-hybrid_rerank{ background: rgba(249,115,22,0.15); color: #fb923c; }

.confidence-bar {
  width: 80px;
  height: 4px;
  background: rgba(255,255,255,0.1);
  border-radius: 2px;
  overflow: hidden;
}
.grade-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
}
.grade-relevant   { background: #22c55e; box-shadow: 0 0 6px #22c55e; }
.grade-partial    { background: #eab308; box-shadow: 0 0 6px #eab308; }
.grade-irrelevant { background: #ef4444; box-shadow: 0 0 6px #ef4444; }