:root {
  --bg: #0f1115;
  --panel: #171a21;
  --panel-2: #1f232c;
  --text: #e7e9ee;
  --muted: #8b90a0;
  --accent: #4c7dff;
  --accent-2: #3a63cc;
  --border: #262b36;
  --danger: #ff5c5c;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  overflow: hidden;
}

.hidden { display: none !important; }
.muted { color: var(--muted); }
.small { font-size: 12px; }
.error { color: var(--danger); font-size: 13px; min-height: 18px; margin-top: 8px; }

/* Авторизация */
.auth {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.auth-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px;
  width: 340px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.auth-card h1 { margin: 0; font-size: 24px; }
.auth-card p { margin: 0 0 8px; }

input, textarea {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  padding: 11px 12px;
  font-size: 14px;
  font-family: inherit;
  outline: none;
  resize: none;
}
input:focus, textarea:focus { border-color: var(--accent); }

button {
  cursor: pointer;
  border: none;
  border-radius: 10px;
  padding: 11px 14px;
  font-size: 14px;
  font-family: inherit;
  transition: background .15s;
}
button.primary { background: var(--accent); color: #fff; }
button.primary:hover { background: var(--accent-2); }
button.ghost { background: transparent; color: var(--muted); border: 1px solid var(--border); }
button.ghost:hover { color: var(--text); }
button.wide { width: 100%; }
button.small { padding: 6px 10px; font-size: 12px; }

/* Основной интерфейс */
.app { display: flex; height: 100vh; }

.sidebar {
  width: 280px;
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 14px;
  gap: 12px;
}
.side-top { display: flex; align-items: center; justify-content: space-between; }
.logo { font-weight: 600; font-size: 16px; }
.badge {
  font-size: 11px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  padding: 3px 9px;
  border-radius: 999px;
  color: var(--muted);
}
.projects { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 4px; }
.project-item {
  padding: 9px 10px;
  border-radius: 9px;
  cursor: pointer;
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.project-item:hover { background: var(--panel-2); color: var(--text); }
.project-item.active { background: var(--panel-2); color: var(--text); }
.side-bottom { display: flex; align-items: center; justify-content: space-between; gap: 8px; }

.chat { flex: 1; display: flex; flex-direction: column; }
.chat-title {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
  color: var(--muted);
}
.messages { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column; gap: 14px; }
.msg { max-width: 760px; padding: 12px 14px; border-radius: 12px; font-size: 14px; line-height: 1.5; white-space: pre-wrap; }
.msg.user { align-self: flex-end; background: var(--accent); color: #fff; }
.msg.assistant { align-self: flex-start; background: var(--panel-2); border: 1px solid var(--border); }
.msg.offtopic { border-color: #5a3a3a; }

.composer {
  display: flex;
  gap: 10px;
  padding: 14px 20px;
  border-top: 1px solid var(--border);
  align-items: flex-end;
}
.composer textarea { flex: 1; max-height: 160px; }