:root {
  --bg: #0f1115;
  --bg-elev: #1a1d25;
  --bg-elev2: #232733;
  --border: #2d3341;
  --fg: #e6e8ee;
  --fg-dim: #9098a8;
  --accent: #e57248;
  --accent-fg: #0f1115;
  --danger: #e05c5c;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--fg);
  font: 14px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  overflow: hidden;
}

body {
  display: grid;
  grid-template-rows: auto 1fr auto;
  height: 100vh;
  height: 100dvh;
}

/* --- header ---------------------------------------------------------------- */

header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--bg-elev);
  border-bottom: 1px solid var(--border);
}

.brand { font-size: 16px; }

.tabs {
  flex: 1;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.tab {
  padding: 6px 12px;
  background: var(--bg-elev2);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  color: var(--fg-dim);
  white-space: nowrap;
  font-size: 13px;
}

.tab:hover { color: var(--fg); }

.tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-fg);
}

.tab .dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #5bd68a;
  margin-right: 6px;
  vertical-align: middle;
}
.tab .dot.off { background: #555b68; }

.tab .tab-owner {
  color: var(--fg-dim);
  font-style: italic;
  margin-right: 2px;
}
.tab.active .tab-owner { color: var(--accent-fg); opacity: 0.7; }

/* --- main ------------------------------------------------------------------ */

main {
  display: grid;
  grid-template-columns: 1fr 280px;
  min-height: 0;
}

.chat {
  padding: 14px 16px;
  overflow-y: auto;
  font-family: var(--mono);
  font-size: 13px;
  white-space: pre-wrap;
  word-break: break-word;
  background: var(--bg);
  color: var(--fg);
}

.chat-empty {
  color: var(--fg-dim);
  font-family: system-ui, sans-serif;
  text-align: center;
  margin-top: 30vh;
}

.sidebar {
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--border);
  background: var(--bg-elev);
  min-height: 0;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
}
.sidebar-header h3 { margin: 0; font-size: 13px; color: var(--fg-dim); text-transform: uppercase; letter-spacing: 0.5px; }

.file-list {
  list-style: none;
  margin: 0;
  padding: 6px 8px;
  overflow-y: auto;
  flex: 1;
}

.file-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 4px;
  font-size: 13px;
}
.file-list li:hover { background: var(--bg-elev2); }

.file-list .name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.file-list .size { color: var(--fg-dim); font-size: 11px; }

.file-list .fbtn {
  background: none;
  border: none;
  color: var(--fg-dim);
  cursor: pointer;
  padding: 2px 6px;
  font-size: 12px;
}
.file-list .fbtn:hover { color: var(--fg); }
.file-list .fbtn.del:hover { color: var(--danger); }

.sidebar-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 10px 12px;
  border-top: 1px solid var(--border);
}

/* --- footer / input row ---------------------------------------------------- */

footer {
  padding: 10px 12px;
  background: var(--bg-elev);
  border-top: 1px solid var(--border);
}

.input-row {
  display: flex;
  gap: 8px;
  align-items: flex-end;
}

#sidebarToggle { display: none; }

textarea {
  flex: 1;
  background: var(--bg-elev2);
  border: 1px solid var(--border);
  color: var(--fg);
  border-radius: 6px;
  padding: 8px 10px;
  font-family: var(--mono);
  font-size: 13px;
  resize: none;
  min-height: 40px;
  max-height: 160px;
}
textarea:focus { outline: 1px solid var(--accent); }

/* --- buttons --------------------------------------------------------------- */

.btn {
  background: var(--bg-elev2);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 14px;
  cursor: pointer;
  font-size: 13px;
  font-family: inherit;
}
.btn:hover { background: #2c313f; }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-primary {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
  font-weight: 600;
}
.btn-primary:hover { filter: brightness(1.08); background: var(--accent); }

.btn-danger { color: var(--danger); }
.btn-danger:hover { background: rgba(224, 92, 92, 0.12); }

.btn-ghost { background: transparent; }

.btn-small {
  padding: 4px 10px;
  font-size: 12px;
}

/* --- dialog ---------------------------------------------------------------- */

dialog {
  background: var(--bg-elev);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  min-width: 300px;
}
dialog::backdrop { background: rgba(0, 0, 0, 0.6); }
dialog h3 { margin: 0 0 12px 0; }
dialog input {
  width: 100%;
  background: var(--bg-elev2);
  border: 1px solid var(--border);
  color: var(--fg);
  border-radius: 6px;
  padding: 8px 10px;
  font-family: var(--mono);
  margin-bottom: 12px;
}
.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}
.dialog-actions button {
  background: var(--bg-elev2);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 14px;
  cursor: pointer;
}

/* scrollbar polish */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--bg-elev2); border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: #353b4a; }