:root {
  --bg: #0d0b1a;
  --bg-panel: #16132a;
  --bg-elev: #1e1a38;
  --border: #2c2750;
  --text: #e8e6f5;
  --muted: #9a95c0;
  --accent: #b06cff;
  --accent2: #35d0c9;
  --user: #2a2350;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: radial-gradient(1200px 600px at 80% -10%, #241a4d 0%, var(--bg) 55%);
  color: var(--text);
  min-height: 100vh;
}

.topbar {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; flex-wrap: wrap;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(13, 11, 26, 0.7);
  backdrop-filter: blur(8px);
}
.brand { display: flex; align-items: center; gap: .8rem; }
.logo { font-size: 2rem; filter: drop-shadow(0 0 10px var(--accent)); }
.topbar h1 { font-size: 1.15rem; margin: 0; letter-spacing: .3px; }
.tagline { margin: .15rem 0 0; font-size: .8rem; color: var(--muted); }
.topbar-right { display: flex; align-items: center; gap: 1.2rem; flex-wrap: wrap; }
.stats { display: flex; gap: 1rem; font-size: .85rem; color: var(--muted); }
.stats b { color: var(--accent2); }
.auth { font-size: .85rem; display: flex; align-items: center; gap: .6rem; }
.auth a.login-btn { text-decoration: none; color: #fff; background: linear-gradient(135deg, var(--accent), #7d4bd6); padding: .45rem .9rem; border-radius: 9px; font-weight: 600; }
.auth .user-name { color: var(--accent2); font-weight: 600; }
.auth a.logout { color: var(--muted); text-decoration: none; }

main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  padding: 1rem 1.5rem;
  max-width: 1500px; margin: 0 auto;
}
@media (max-width: 900px) { main { grid-template-columns: 1fr; } }

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  display: flex; flex-direction: column;
  overflow: hidden;
}

/* Chat */
.chat-panel { min-height: 70vh; }
.messages { flex: 1; overflow-y: auto; padding: 1rem; display: flex; flex-direction: column; gap: .8rem; }
.msg { padding: .8rem 1rem; border-radius: 12px; line-height: 1.5; font-size: .95rem; max-width: 92%; }
.msg.bot { background: var(--bg-elev); border: 1px solid var(--border); align-self: flex-start; }
.msg.user { background: var(--user); align-self: flex-end; }
.msg p { margin: 0 0 .5rem; }
.msg p:last-child { margin: 0; }
.sources { margin-top: .6rem; font-size: .8rem; color: var(--muted); border-top: 1px dashed var(--border); padding-top: .5rem; }
.sources a { color: var(--accent2); text-decoration: none; }
.sources li { margin: .2rem 0; }
.thinking { color: var(--muted); font-style: italic; }

.chat-form { display: flex; gap: .5rem; padding: .8rem; border-top: 1px solid var(--border); }
.chat-form input { flex: 1; padding: .7rem .9rem; border-radius: 10px; border: 1px solid var(--border); background: var(--bg); color: var(--text); font-size: .95rem; }
.chat-form input:focus { outline: none; border-color: var(--accent); }
button { cursor: pointer; border: none; border-radius: 10px; padding: .7rem 1.1rem; font-weight: 600; color: #fff; background: linear-gradient(135deg, var(--accent), #7d4bd6); }
button:disabled { opacity: .5; cursor: default; }
button.ghost { background: transparent; border: 1px solid var(--border); color: var(--muted); padding: .4rem .8rem; font-weight: 500; }

/* Grafo */
.graph-panel { min-height: 70vh; }
.graph-header { display: flex; align-items: center; justify-content: space-between; padding: .8rem 1rem; border-bottom: 1px solid var(--border); }
.graph-header h2 { font-size: 1rem; margin: 0; }
#cy { flex: 1; min-height: 400px; background: radial-gradient(600px 400px at 50% 30%, #1a1636 0%, var(--bg-panel) 70%); }
.legend { display: flex; flex-wrap: wrap; gap: .5rem .9rem; padding: .7rem 1rem; border-top: 1px solid var(--border); font-size: .75rem; color: var(--muted); }
.legend .dot { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-right: .35rem; vertical-align: middle; }

/* Admin */
.admin { max-width: 1500px; margin: 0 auto 2rem; padding: 0 1.5rem; }
.admin summary { cursor: pointer; color: var(--muted); padding: .6rem 0; }
.admin-body { display: flex; flex-direction: column; gap: .7rem; max-width: 480px; background: var(--bg-panel); border: 1px solid var(--border); border-radius: 12px; padding: 1rem; }
.admin-body label { display: flex; flex-direction: column; gap: .3rem; font-size: .85rem; color: var(--muted); }
.admin-body input { padding: .55rem .7rem; border-radius: 8px; border: 1px solid var(--border); background: var(--bg); color: var(--text); }
.upload-status { font-size: .85rem; margin: 0; color: var(--accent2); }