:root {
  --bg: #0f1115;
  --panel: #1a1d24;
  --panel-2: #22262f;
  --border: #2d313b;
  --text: #e8eaed;
  --text-dim: #9aa1ad;
  --accent: #6d7fff;
  --accent-hover: #5a6ef0;
  --danger: #ff6b6b;
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  font-family: -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
}

/* --- Login --- */
.login-body { display: flex; align-items: center; justify-content: center; }
.login-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px;
  width: 320px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.login-card h1 { margin: 0 0 8px; font-size: 20px; text-align: center; }
.login-card label { display: flex; flex-direction: column; gap: 6px; font-size: 13px; color: var(--text-dim); }
.login-card input {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  color: var(--text);
  font-size: 14px;
}
.login-card button {
  background: var(--accent);
  border: none;
  border-radius: 8px;
  padding: 10px;
  color: white;
  font-size: 14px;
  cursor: pointer;
}
.login-card button:hover { background: var(--accent-hover); }
.error { color: var(--danger); font-size: 13px; margin: 0; }

/* --- App layout --- */
.layout { display: flex; height: 100vh; }

.sidebar {
  width: 260px;
  flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 12px;
}
.new-chat-btn {
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: white;
  padding: 10px;
  font-size: 14px;
  cursor: pointer;
  margin-bottom: 12px;
}
.new-chat-btn:hover { background: var(--accent-hover); }
.session-list { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 4px; }
.session-item {
  padding: 9px 10px;
  border-radius: 8px;
  font-size: 13px;
  color: var(--text-dim);
  cursor: pointer;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.session-item:hover { background: var(--panel-2); }
.session-item.active { background: var(--panel-2); color: var(--text); }
.sidebar-tabs { display: flex; gap: 4px; margin-bottom: 8px; }
.sidebar-tab {
  flex: 1;
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-dim);
  padding: 6px;
  font-size: 12px;
  cursor: pointer;
}
.sidebar-tab.active { background: var(--panel-2); color: var(--text); }

.file-list { flex: 1; overflow-y: auto; font-size: 13px; }
.file-row { padding: 5px 6px; border-radius: 6px; cursor: pointer; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: var(--text-dim); }
.file-row:hover { background: var(--panel-2); color: var(--text); }
.file-children { padding-left: 14px; }

.file-viewer {
  position: fixed;
  inset: 0;
  background: var(--bg);
  z-index: 50;
  display: flex;
  flex-direction: column;
}
.file-viewer-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}
#fileViewerContent {
  flex: 1;
  margin: 0;
  padding: 20px;
  overflow: auto;
  white-space: pre-wrap;
  font-size: 13px;
  line-height: 1.5;
}

.sidebar-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-dim);
}
.sidebar-footer span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.link-btn { background: none; border: none; color: var(--accent); cursor: pointer; font-size: 13px; }

.chat-pane { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.messages { flex: 1; overflow-y: auto; padding: 24px; display: flex; flex-direction: column; gap: 14px; }
.msg { max-width: 720px; padding: 10px 14px; border-radius: 12px; white-space: pre-wrap; line-height: 1.5; font-size: 14.5px; }
.msg-user { align-self: flex-end; background: var(--accent); color: white; }
.msg-assistant { align-self: flex-start; background: var(--panel-2); border: 1px solid var(--border); }

.composer { border-top: 1px solid var(--border); padding: 12px 16px; background: var(--panel); }
.attachment-chips { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 8px; }
.chip {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.chip button { background: none; border: none; color: var(--text-dim); cursor: pointer; font-size: 14px; }

.composer-row {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 8px;
}
#promptInput {
  flex: 1;
  resize: none;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 14.5px;
  font-family: inherit;
  max-height: 200px;
  outline: none;
  padding: 6px 4px;
}
.icon-btn {
  background: none;
  border: none;
  font-size: 18px;
  cursor: pointer;
  padding: 6px;
  border-radius: 8px;
  line-height: 1;
}
.icon-btn:hover { background: var(--border); }
.icon-btn.recording { background: var(--danger); }
.send-btn {
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: white;
  padding: 8px 16px;
  font-size: 14px;
  cursor: pointer;
}
.send-btn:hover { background: var(--accent-hover); }