/* ── Reset & Base ─────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:          #030303;
  --bg-2:        #0c0c0c;
  --bg-3:        #141414;
  --bg-4:        #1e1e1e;
  --border:      #1f1f1f;
  --border-2:    #2a2a2a;
  --border-3:    #383838;
  --text:        #f2f2f2;
  --text-2:      #888888;
  --text-3:      #444444;
  --accent:      #ffffff;
  --accent-dim:  rgba(255,255,255,.06);
  --accent-dim2: rgba(255,255,255,.12);
  --green:       #a3a3a3;
  --green-dim:   rgba(163,163,163,.1);
  --red:         #c0c0c0;
  --red-dim:     rgba(120,120,120,.12);
  --grad:        linear-gradient(135deg, #fff 0%, #666 100%);
  --grad-soft:   linear-gradient(135deg, #e0e0e0 0%, #505050 100%);
  --grad-border: linear-gradient(135deg, #2e2e2e, #111);
  --radius:      14px;
  --radius-sm:   10px;
  --radius-xs:   7px;
  --shadow:      0 8px 40px rgba(0,0,0,.7);
  --shadow-sm:   0 2px 12px rgba(0,0,0,.5);
  --font:        'Inter', system-ui, sans-serif;
  --sidebar-w:   280px;
  --trans:       150ms ease;
}

html { height: 100%; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  height: 100%;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ── Screens ──────────────────────────────────────────────────────────────── */
.screen {
  position: fixed;
  inset: 0;
  transition: opacity .28s ease, transform .28s ease;
}
.screen.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
}

/* ═══════════════════════════════════════════════════════════════════════════
   SCREEN 1 — UPLOAD
═══════════════════════════════════════════════════════════════════════════ */
#screen-upload {
  display: flex;
  flex-direction: column;
  background: var(--bg);
}

/* ── Nav ──────────────────────────────────────────────────────────────────── */
.upload-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 36px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-2);
  flex-shrink: 0;
}

.logo { display: flex; align-items: center; gap: 11px; }
.logo-icon {
  width: 34px; height: 34px;
  border-radius: var(--radius-xs);
  background: var(--grad);
  display: flex; align-items: center; justify-content: center;
  color: #000;
  flex-shrink: 0;
}
.logo-icon.sm { width: 27px; height: 27px; }
.logo-text {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -.4px;
  color: var(--text);
}

.nav-badges { display: flex; gap: 8px; flex-wrap: wrap; }
.nbadge {
  font-size: 11px;
  font-weight: 500;
  padding: 4px 11px;
  border-radius: 20px;
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  color: var(--text-2);
  white-space: nowrap;
}
.nbadge.green {
  background: var(--green-dim);
  border-color: rgba(200,200,200,.15);
  color: #b0b0b0;
}

/* ── Upload main ──────────────────────────────────────────────────────────── */
.upload-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 48px 24px;
  overflow-y: auto;
  gap: 30px;
}

/* Hero */
.upload-hero { text-align: center; }
.hero-title {
  font-size: clamp(30px, 4.5vw, 50px);
  font-weight: 800;
  letter-spacing: -.6px;
  line-height: 1.18;
  color: var(--text);
}
.hero-accent {
  background: var(--grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-sub {
  margin-top: 14px;
  font-size: 15px;
  color: var(--text-2);
  max-width: 440px;
  line-height: 1.65;
  margin-left: auto;
  margin-right: auto;
}

/* Drop zone */
.upload-card {
  width: 100%;
  max-width: 540px;
  background: var(--bg-2);
  border: 1.5px dashed var(--border-2);
  border-radius: var(--radius);
  padding: 48px 36px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--trans), background var(--trans);
  position: relative;
}
.upload-card:hover,
.upload-card.drag-over {
  border-color: var(--border-3);
  background: var(--bg-3);
}
.upload-card.drag-over { border-style: solid; border-color: rgba(255,255,255,.35); }

.drop-icon {
  width: 58px; height: 58px;
  border-radius: var(--radius-sm);
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 18px;
  color: var(--text-2);
}

.drop-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 7px;
}
.drop-sub { font-size: 14px; color: var(--text-2); }
.link-btn {
  background: none;
  border: none;
  color: var(--text);
  cursor: pointer;
  font-size: 14px;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border-3);
  padding: 0;
  transition: text-decoration-color var(--trans);
}
.link-btn:hover { text-decoration-color: #fff; }

.drop-formats {
  margin-top: 16px;
  font-size: 11.5px;
  color: var(--text-3);
  letter-spacing: .8px;
  text-transform: uppercase;
}

/* Progress */
.upload-progress {
  margin-top: 24px;
  text-align: left;
}
.progress-label {
  font-size: 12.5px;
  color: var(--text-2);
  margin-bottom: 9px;
  font-weight: 500;
}
.progress-track {
  height: 3px;
  background: var(--bg-4);
  border-radius: 99px;
  overflow: hidden;
}
.progress-bar {
  height: 100%;
  width: 0%;
  background: var(--grad-soft);
  border-radius: 99px;
  transition: width .4s ease;
}
.upload-error {
  margin-top: 14px;
  font-size: 13px;
  color: #888;
  background: var(--red-dim);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-xs);
  padding: 10px 14px;
  text-align: left;
}

/* Or divider */
.upload-or {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: 540px;
  gap: 14px;
  color: var(--text-3);
  font-size: 12.5px;
}
.upload-or::before,
.upload-or::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* Load saved */
.load-saved-btn {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 11px 24px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--trans), border-color var(--trans), color var(--trans);
}
.load-saved-btn:hover {
  background: var(--bg-4);
  border-color: var(--border-3);
  color: var(--text);
}

/* Feature pills */
.feature-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  max-width: 580px;
}
.fpill {
  font-size: 11.5px;
  font-weight: 500;
  padding: 5px 13px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: 20px;
  color: var(--text-2);
}

/* ═══════════════════════════════════════════════════════════════════════════
   SCREEN 2 — CHAT
═══════════════════════════════════════════════════════════════════════════ */
#screen-chat {
  display: flex;
  background: var(--bg);
}

/* ── Sidebar ──────────────────────────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--bg-2);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

.sidebar-logo {
  padding: 18px 20px 15px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-section {
  padding: 18px 16px 14px;
  border-bottom: 1px solid var(--border);
}
.sidebar-label {
  font-size: 10.5px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .9px;
  color: var(--text-3);
  margin-bottom: 11px;
}

/* Doc card */
.doc-card {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  padding: 11px 13px;
}
.doc-icon { color: var(--text-2); flex-shrink: 0; margin-top: 1px; }
.doc-info { min-width: 0; }
.doc-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 175px;
}
.doc-stats { font-size: 11.5px; color: var(--text-3); margin-top: 3px; }

/* Toggles */
.toggle-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 0;
  gap: 12px;
}
.toggle-info { min-width: 0; flex: 1; }
.toggle-name {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
}
.toggle-desc {
  display: block;
  font-size: 11px;
  color: var(--text-3);
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.toggle {
  position: relative;
  display: inline-block;
  width: 38px; height: 22px;
  flex-shrink: 0;
}
.toggle input { opacity: 0; width: 0; height: 0; }
.slider {
  position: absolute;
  inset: 0;
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  border-radius: 22px;
  cursor: pointer;
  transition: background var(--trans), border-color var(--trans);
}
.slider::before {
  content: '';
  position: absolute;
  width: 16px; height: 16px;
  left: 2px; top: 2px;
  background: var(--text-3);
  border-radius: 50%;
  transition: transform var(--trans), background var(--trans);
}
.toggle input:checked + .slider {
  background: #fff;
  border-color: #fff;
}
.toggle input:checked + .slider::before {
  transform: translateX(16px);
  background: #000;
}

/* New session */
.sidebar-bottom {
  margin-top: auto;
  padding: 16px;
  border-top: 1px solid var(--border);
}
.new-session-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 10px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--trans), border-color var(--trans), color var(--trans);
}
.new-session-btn:hover {
  background: var(--bg-4);
  border-color: var(--border-3);
  color: var(--text);
}

/* ── Chat main ────────────────────────────────────────────────────────────── */
.chat-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100vh;
}

/* Messages */
.messages {
  flex: 1;
  overflow-y: auto;
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  gap: 26px;
  scroll-behavior: smooth;
}
.messages::-webkit-scrollbar { width: 4px; }
.messages::-webkit-scrollbar-track { background: transparent; }
.messages::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 2px; }

/* Empty state */
.empty-state {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 64px 32px;
}
.empty-icon {
  width: 64px; height: 64px;
  border-radius: var(--radius-sm);
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  display: flex; align-items: center; justify-content: center;
  color: var(--text-3);
  margin-bottom: 20px;
}
.empty-title {
  font-size: 19px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
  letter-spacing: -.2px;
}
.empty-sub {
  font-size: 14px;
  color: var(--text-2);
  max-width: 300px;
  line-height: 1.6;
}

/* Messages */
.msg {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-width: 840px;
  width: 100%;
  margin: 0 auto;
}

.msg-user { align-items: flex-end; }
.msg-user .msg-bubble {
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  color: var(--text);
  border-radius: 18px 18px 4px 18px;
}

.msg-assistant { align-items: flex-start; }
.msg-assistant .msg-bubble {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 4px 18px 18px 18px;
}

.msg-bubble {
  padding: 14px 18px;
  font-size: 14.5px;
  line-height: 1.7;
  max-width: 100%;
  word-break: break-word;
}
.msg-bubble p { margin-bottom: 10px; }
.msg-bubble p:last-child { margin-bottom: 0; }
.msg-bubble strong { color: #fff; font-weight: 600; }
.msg-bubble code {
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  padding: 1px 6px;
  border-radius: 4px;
  font-family: ui-monospace, monospace;
  font-size: 13px;
  color: #d0d0d0;
}
.msg-bubble pre {
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  padding: 14px;
  border-radius: var(--radius-xs);
  overflow-x: auto;
  margin: 10px 0;
  font-size: 13px;
}

/* Streaming cursor */
.cursor {
  display: inline-block;
  width: 2px; height: 15px;
  background: var(--text-2);
  border-radius: 2px;
  vertical-align: text-bottom;
  margin-left: 2px;
  animation: blink .7s step-end infinite;
}
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0} }

/* Sources toggle button */
.sources-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  padding: 5px 11px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: 20px;
  color: var(--text-2);
  font-size: 12px;
  font-weight: 500;
  font-family: var(--font);
  cursor: pointer;
  transition: background var(--trans), border-color var(--trans), color var(--trans);
}
.sources-toggle-btn:hover,
.sources-toggle-btn.open {
  background: var(--bg-4);
  border-color: var(--border-3);
  color: var(--text);
}
.sources-count {
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  border-radius: 10px;
  padding: 0 5px;
  font-size: 10.5px;
  color: var(--text-3);
}
.sources-toggle-btn.open .sources-count {
  color: var(--text-2);
}

/* Sources grid */
.sources-grid {
  margin-top: 10px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 8px;
}
.source-card {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 13px 14px;
  cursor: default;
  transition: border-color var(--trans), background var(--trans);
}
.source-card:hover { border-color: var(--border-3); background: var(--bg-3); }
.source-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}
.source-idx {
  font-size: 11px;
  font-weight: 700;
  color: #888;
  background: var(--bg-4);
  width: 22px; height: 22px;
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--border-2);
}
.source-score { font-size: 11px; color: var(--text-3); font-weight: 500; }
.source-fname {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-2);
  margin-bottom: 5px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.source-excerpt {
  font-size: 12px;
  color: var(--text-3);
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Confidence */
.confidence-row {
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: 840px;
  width: 100%;
  margin: 0 auto;
}
.conf-label { font-size: 12px; color: var(--text-3); font-weight: 500; }
.conf-bar-track {
  flex: 1;
  height: 3px;
  background: var(--bg-4);
  border-radius: 99px;
  overflow: hidden;
  max-width: 180px;
}
.conf-bar-fill {
  height: 100%;
  background: var(--grad-soft);
  border-radius: 99px;
}
.conf-pct { font-size: 12px; color: #888; font-weight: 600; }

/* Thinking spinner */
.thinking-row {
  display: flex;
  align-items: center;
  gap: 11px;
  max-width: 840px;
  width: 100%;
  margin: 0 auto;
  padding: 6px 0;
}
.spinner {
  width: 17px; height: 17px;
  border: 2px solid var(--border-2);
  border-top-color: var(--text-2);
  border-radius: 50%;
  animation: spin .75s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.thinking-text { font-size: 13px; color: var(--text-3); }

/* ── Input area ───────────────────────────────────────────────────────────── */
.input-area {
  flex-shrink: 0;
  padding: 16px 28px 22px;
  background: var(--bg);
  border-top: 1px solid var(--border);
}
.input-wrap {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: 11px 11px 11px 18px;
  transition: border-color var(--trans);
}
.input-wrap:focus-within { border-color: var(--border-3); }

.question-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text);
  font-family: var(--font);
  font-size: 14.5px;
  line-height: 1.55;
  resize: none;
  min-height: 24px;
  max-height: 180px;
  overflow-y: auto;
}
.question-input::placeholder { color: var(--text-3); }
.question-input::-webkit-scrollbar { width: 4px; }
.question-input::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 2px; }

.send-btn {
  width: 38px; height: 38px;
  border-radius: var(--radius-xs);
  background: #fff;
  border: none;
  display: flex; align-items: center; justify-content: center;
  color: #000;
  cursor: pointer;
  flex-shrink: 0;
  transition: background var(--trans), opacity var(--trans);
}
.send-btn:hover { background: #d4d4d4; }
.send-btn:disabled { opacity: .25; cursor: not-allowed; }

.input-hint {
  font-size: 11.5px;
  color: var(--text-3);
  text-align: center;
  margin-top: 10px;
}
.input-hint kbd {
  display: inline-block;
  padding: 1px 6px;
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  border-radius: 4px;
  font-size: 10.5px;
  font-family: var(--font);
  color: var(--text-2);
}

/* ── Visualization button ────────────────────────────────────────────────── */
.viz-btn {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 10px 12px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 13px;
  font-weight: 500;
  font-family: var(--font);
  cursor: pointer;
  transition: background var(--trans), border-color var(--trans), color var(--trans);
}
.viz-btn:hover {
  background: var(--bg-4);
  border-color: var(--border-3);
  color: var(--text);
}

/* ── Embedding modal ─────────────────────────────────────────────────────── */
.emb-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.78);
  backdrop-filter: blur(5px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.emb-panel {
  width: min(92vw, 980px);
  height: min(88vh, 720px);
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.emb-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 18px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.emb-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  flex: 1;
  letter-spacing: -.2px;
}
.emb-level-label {
  font-size: 11px;
  color: var(--text-3);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: .6px;
}
.emb-separator {
  width: 1px;
  height: 18px;
  background: var(--border-2);
}

.emb-dim-toggle {
  display: flex;
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-xs);
  padding: 3px;
  gap: 3px;
}
.emb-dim-btn {
  padding: 5px 16px;
  font-size: 12px;
  font-weight: 600;
  font-family: var(--font);
  border: 1px solid transparent;
  border-radius: 5px;
  background: transparent;
  color: var(--text-3);
  cursor: pointer;
  transition: background var(--trans), color var(--trans), border-color var(--trans);
}
.emb-dim-btn.active {
  background: var(--bg-3);
  border-color: var(--border-2);
  color: var(--text);
}

.emb-close {
  width: 30px; height: 30px;
  border-radius: var(--radius-xs);
  background: none;
  border: 1px solid var(--border-2);
  color: var(--text-2);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px;
  line-height: 1;
  transition: background var(--trans), color var(--trans);
}
.emb-close:hover { background: var(--bg-4); color: var(--text); }

.emb-canvas-wrap {
  flex: 1;
  position: relative;
  overflow: hidden;
  background: var(--bg-3);
}
#emb-canvas-2d {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  cursor: grab;
  display: block;
}
#emb-canvas-2d:active { cursor: grabbing; }
#emb-canvas-3d {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
#emb-canvas-3d canvas {
  display: block;
  width: 100% !important;
  height: 100% !important;
}

.emb-tooltip {
  position: absolute;
  background: var(--bg);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-xs);
  padding: 8px 12px;
  font-size: 12px;
  color: var(--text-2);
  max-width: 300px;
  pointer-events: none;
  z-index: 10;
  line-height: 1.55;
  box-shadow: var(--shadow-sm);
  word-break: break-word;
}

.emb-loading {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  color: var(--text-3);
  background: var(--bg-3);
}

.emb-footer {
  flex-shrink: 0;
  padding: 10px 20px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  min-height: 44px;
}
.emb-legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11.5px;
  color: var(--text-2);
}
.emb-legend-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}
.emb-variance {
  margin-left: auto;
  font-size: 11px;
  color: var(--text-3);
  font-variant-numeric: tabular-nums;
}

/* ── Utility ──────────────────────────────────────────────────────────────── */
.hidden { display: none !important; }