:root {
  --bg: #f7f7f8;
  --sidebar-bg: #191a1f;
  --sidebar-text: #d7d8dd;
  --sidebar-muted: #8b8d98;
  --accent: #5b5bf6;
  --accent-hover: #4747e0;
  --bubble-user: #5b5bf6;
  --bubble-user-text: #ffffff;
  --bubble-assistant: #ffffff;
  --border: #e6e6ea;
  --text: #1c1c22;
  --muted: #767785;
  --step-bg: #f1f1fb;
  --step-border: #dcdcf7;
  --radius: 14px;
  font-family: "Inter", "Noto Sans Bengali", sans-serif;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
  background: var(--bg);
  color: var(--text);
}

.app {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ---------------- Sidebar ---------------- */
.sidebar {
  width: 268px;
  flex-shrink: 0;
  background: var(--sidebar-bg);
  color: var(--sidebar-text);
  display: flex;
  flex-direction: column;
  padding: 14px;
}

.new-chat-btn {
  width: 100%;
  padding: 11px 14px;
  border-radius: 10px;
  border: 1px solid #33343c;
  background: #232429;
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: background 0.15s;
}
.new-chat-btn:hover { background: #2c2d34; }
.new-chat-btn .icon { color: var(--accent); font-weight: 700; }

.thread-list {
  flex: 1;
  overflow-y: auto;
  margin-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.thread-item {
  padding: 9px 10px;
  border-radius: 8px;
  font-size: 13.5px;
  color: var(--sidebar-muted);
  cursor: pointer;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 6px;
}
.thread-item:hover { background: #232429; color: var(--sidebar-text); }
.thread-item.active { background: #2a2b39; color: #fff; }
.thread-item .del {
  opacity: 0;
  font-size: 12px;
  color: var(--sidebar-muted);
}
.thread-item:hover .del { opacity: 1; }

.sidebar-footer {
  border-top: 1px solid #2b2c33;
  padding-top: 12px;
  margin-top: 8px;
}
.owner-badge { display: flex; align-items: center; gap: 10px; }
.owner-avatar {
  width: 32px; height: 32px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; color: #fff; font-size: 14px;
}
.owner-name { font-size: 13px; font-weight: 600; color: #fff; }
.owner-sub { font-size: 11.5px; color: var(--sidebar-muted); }

/* ---------------- Main ---------------- */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.topbar {
  padding: 14px 24px;
  border-bottom: 1px solid var(--border);
  background: #fff;
}
.topbar-title { font-size: 15px; font-weight: 600; }
.topbar-sub { font-size: 12px; color: var(--muted); margin-top: 2px; }

.chat-scroll {
  flex: 1;
  overflow-y: auto;
  padding: 24px 0 8px;
}

.empty-state {
  max-width: 520px;
  margin: 12vh auto;
  text-align: center;
  color: var(--muted);
}
.empty-icon { font-size: 40px; margin-bottom: 10px; }
.empty-state h2 { font-size: 18px; color: var(--text); margin: 0 0 8px; }
.empty-state p { font-size: 13.5px; line-height: 1.6; }

.messages {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.msg-row { display: flex; }
.msg-row.user { justify-content: flex-end; }
.msg-row.assistant { justify-content: flex-start; }

.bubble {
  max-width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: 14.5px;
  line-height: 1.65;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.msg-row.user .bubble {
  background: var(--bubble-user);
  color: var(--bubble-user-text);
  border-bottom-right-radius: 4px;
}
.msg-row.assistant .bubble-wrap {
  width: 100%;
}
.msg-row.assistant .bubble {
  background: var(--bubble-assistant);
  border: 1px solid var(--border);
  border-bottom-left-radius: 4px;
}

/* ---------------- Steps (Manus-style action timeline) ---------------- */
.steps {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 10px;
}

.step {
  background: var(--step-bg);
  border: 1px solid var(--step-border);
  border-radius: 10px;
  padding: 8px 12px;
  font-size: 13px;
}
.step-head {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}
.step-icon { font-size: 14px; }
.step-label { flex: 1; color: #3b3b6e; font-weight: 500; }
.step-status {
  font-size: 11px;
  color: var(--accent);
}
.step.done .step-status { color: #16a34a; }
.step.done .step-status::before { content: "✓ "; }
.step-detail {
  margin: 8px 0 0;
  padding: 8px 10px;
  background: #ffffff;
  border: 1px solid var(--step-border);
  border-radius: 8px;
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px;
  white-space: pre-wrap;
  word-break: break-word;
  max-height: 220px;
  overflow-y: auto;
  color: #444;
}

/* ---------------- Composer ---------------- */
.composer {
  border-top: 1px solid var(--border);
  background: #fff;
  padding: 12px 20px 18px;
}
.attachment-chip {
  max-width: 760px;
  margin: 0 auto 8px;
  background: var(--step-bg);
  border: 1px solid var(--step-border);
  border-radius: 8px;
  padding: 6px 10px;
  font-size: 12.5px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.attachment-chip button {
  background: none; border: none; cursor: pointer; color: var(--muted);
}

.composer-row {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  align-items: flex-end;
  gap: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 8px 10px;
}
.attach-btn, .send-btn {
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 17px;
  width: 34px; height: 34px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: var(--muted);
  flex-shrink: 0;
}
.attach-btn:hover { background: #ececf3; }
.send-btn { background: var(--accent); color: #fff; }
.send-btn:hover { background: var(--accent-hover); }
.send-btn:disabled { opacity: 0.5; cursor: not-allowed; }

#textInput {
  flex: 1;
  border: none;
  background: transparent;
  resize: none;
  font-size: 14.5px;
  font-family: inherit;
  outline: none;
  max-height: 160px;
  padding: 6px 4px;
  line-height: 1.5;
}

/* Scrollbars */
.thread-list::-webkit-scrollbar, .chat-scroll::-webkit-scrollbar, .step-detail::-webkit-scrollbar {
  width: 6px;
}
.thread-list::-webkit-scrollbar-thumb { background: #33343c; border-radius: 3px; }
.chat-scroll::-webkit-scrollbar-thumb { background: #d7d7dd; border-radius: 3px; }