:root {
  --bg: #f6f7f9;
  --fg: #1c2024;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-soft: #eff4ff;
  --card: #ffffff;
  --border: #e5e7eb;
  --green: #15803d;
  --amber: #b45309;
  --red: #b91c1c;
  --topbar-h: 52px;
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--fg);
  background: var(--bg);
}

/* ---- login ---- */
.centered { min-height: 100vh; display: grid; place-items: center; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  max-width: 480px;
  width: calc(100% - 2rem);
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}
h1 { margin: 0 0 .25rem; font-size: 1.6rem; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }

.btn {
  display: inline-block;
  padding: .55rem 1rem;
  background: var(--accent);
  color: #fff;
  border: none;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  font-size: .9rem;
  cursor: pointer;
}
.btn:disabled { opacity: .5; cursor: default; }
.btn.ghost { background: transparent; color: var(--muted); border: 1px solid var(--border); }
.btn.block { width: 100%; margin-bottom: .75rem; }

/* ---- topbar ---- */
.topbar {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: var(--topbar-h);
  padding: 0 1.25rem;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
.topbar .spacer { flex: 1; }
.topbar a { text-decoration: none; }
.badge {
  font-size: .72rem;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 999px;
  padding: .15rem .55rem;
}

/* ---- layout ---- */
.layout {
  display: flex;
  height: calc(100vh - var(--topbar-h));
}
.sidebar {
  width: 250px;
  border-right: 1px solid var(--border);
  padding: 1rem .75rem;
  overflow-y: auto;
  background: var(--card);
}
.session-list { display: flex; flex-direction: column; gap: .25rem; }
.session-item {
  text-align: left;
  border: none;
  background: transparent;
  padding: .5rem .6rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: .88rem;
  color: var(--fg);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.session-item:hover { background: var(--bg); }
.session-item.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

/* ---- chat ---- */
.chat { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.transcript {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: .75rem;
}
.empty-state { margin: auto; text-align: center; max-width: 420px; }
.empty-state h2 { margin: 0 0 .25rem; }
.examples { display: flex; flex-wrap: wrap; gap: .5rem; justify-content: center; margin-top: 1rem; }
.example {
  border: 1px solid var(--border);
  background: var(--card);
  border-radius: 999px;
  padding: .4rem .8rem;
  font-size: .82rem;
  cursor: pointer;
  color: var(--fg);
}
.example:hover { border-color: var(--accent); color: var(--accent); }

.msg { display: flex; }
.msg.user { justify-content: flex-end; }
.bubble {
  max-width: 760px;
  padding: .7rem .9rem;
  border-radius: 12px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.msg.user .bubble { background: var(--accent); color: #fff; border-bottom-right-radius: 4px; }
.msg.assistant .bubble { background: var(--card); border: 1px solid var(--border); border-bottom-left-radius: 4px; }
.bubble a { color: inherit; }
.msg.assistant .bubble a { color: var(--accent); }

.thinking { color: var(--muted); font-size: .85rem; font-style: italic; padding-left: .25rem; }
.thinking::after { content: ""; animation: dots 1.2s steps(4,end) infinite; }
@keyframes dots { 0%{content:""} 25%{content:"."} 50%{content:".."} 75%{content:"..."} }

.tool-chip {
  align-self: flex-start;
  font-size: .8rem;
  color: var(--muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: .25rem .7rem;
}
.tool-chip.running { color: var(--accent); border-color: var(--accent); }

/* ---- tool result card ---- */
.tool-card {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--card);
  padding: .7rem .85rem;
  max-width: 760px;
}
.tool-card-head { display: flex; align-items: baseline; gap: .6rem; flex-wrap: wrap; }
.tool-name { font-weight: 600; color: var(--green); }
.tool-sum { color: var(--muted); font-size: .85rem; }
.tool-links { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: .6rem; }
.download {
  font-size: .82rem;
  text-decoration: none;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 6px;
  padding: .35rem .7rem;
  font-weight: 600;
}
.tool-raw { margin-top: .5rem; }
.tool-raw summary { cursor: pointer; color: var(--muted); font-size: .78rem; }
.tool-raw pre {
  max-height: 260px;
  overflow: auto;
  background: #0f172a;
  color: #e2e8f0;
  padding: .6rem;
  border-radius: 6px;
  font-size: .72rem;
  margin: .4rem 0 0;
}

/* ---- approval card ---- */
.approval-card {
  border: 1px solid var(--amber);
  background: #fffbeb;
  border-radius: 10px;
  padding: .8rem .9rem;
  max-width: 760px;
}
.approval-card.resolved { opacity: .7; }
.approval-title { font-weight: 600; color: var(--amber); margin-bottom: .4rem; }
.approval-item { margin: .2rem 0; }
.approval-desc { font-size: .9rem; }
.approval-actions { display: flex; gap: .5rem; margin-top: .6rem; }

.error-note {
  align-self: flex-start;
  color: var(--red);
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: 8px;
  padding: .5rem .75rem;
  font-size: .85rem;
}

/* ---- composer ---- */
.composer {
  display: flex;
  gap: .6rem;
  padding: .9rem 1.25rem;
  border-top: 1px solid var(--border);
  background: var(--card);
  align-items: flex-end;
}
.composer textarea {
  flex: 1;
  resize: none;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: .6rem .8rem;
  font: inherit;
  line-height: 1.4;
  max-height: 180px;
}
.composer textarea:focus { outline: none; border-color: var(--accent); }