:root {
  --sidebar-width: 300px;
  --bg: #f6f7f9;
  --bg-soft: #ffffff;
  --bg-card: #ffffff;
  --bg-elev: #f1f3f6;
  --border: #e3e6ec;
  --border-soft: #ecedf1;
  --fg: #1f2430;
  --fg-dim: #555c6c;
  --fg-mute: #8b90a0;
  --accent: #d69a3c;
  --accent-soft: #b97f20;
  --accent-bg: #fcf3e1;
  --user: #eaf1fb;
  --user-border: #c8d9f1;
  --assistant: #ffffff;
  --assistant-border: #e3e6ec;
  --danger: #d14343;
  --ok: #3aa05f;
  --shadow: 0 1px 2px rgba(20, 25, 40, 0.04), 0 4px 12px rgba(20, 25, 40, 0.04);
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue",
    Helvetica, Arial, "Microsoft YaHei", sans-serif;
  --msg-bg: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(248, 249, 252, 0.94));
  --msg-border: rgba(227, 230, 236, 0.9);
  --msg-shadow: 0 18px 34px rgba(20, 25, 40, 0.04), 0 2px 6px rgba(20, 25, 40, 0.04);
  --user-msg-bg: linear-gradient(180deg, rgba(234, 241, 251, 0.98), rgba(225, 236, 251, 0.92));
  --user-msg-border: rgba(190, 212, 243, 0.95);
  --assistant-msg-bg: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(248, 249, 252, 0.94));
  --assistant-msg-border: rgba(227, 230, 236, 0.95);
  --code-bg: #0f172a;
  --code-toolbar-bg: linear-gradient(180deg, rgba(30, 41, 59, 0.98), rgba(15, 23, 42, 0.96));
  --code-border: rgba(51, 65, 85, 0.95);
  --code-fg: #e5edf7;
  --code-muted: #94a3b8;
  --code-keyword: #c084fc;
  --code-string: #a7f3d0;
  --code-number: #f9a8d4;
  --code-title: #93c5fd;
  --code-attr: #fbbf24;
  --code-comment: #64748b;
  --code-link: #67e8f9;
  --code-variable: #fdba74;
  --file-empty-bg: rgba(255, 255, 255, 0.72);
  --file-empty-border: rgba(138, 148, 168, 0.42);
  --file-empty-fg: #7a8598;
}

body.theme-dark {
  --bg: #0b1220;
  --bg-soft: #0f172a;
  --bg-card: #111c31;
  --bg-elev: #152033;
  --border: #22324d;
  --border-soft: #1c2940;
  --fg: #e6edf7;
  --fg-dim: #c0cad9;
  --fg-mute: #8291a9;
  --accent: #e3ab48;
  --accent-soft: #f0be68;
  --accent-bg: rgba(227, 171, 72, 0.12);
  --user: #16253d;
  --user-border: #2d466d;
  --assistant: #0f172a;
  --assistant-border: #22324d;
  --shadow: 0 18px 34px rgba(0, 0, 0, 0.34), 0 2px 6px rgba(0, 0, 0, 0.24);
  --msg-bg: linear-gradient(180deg, rgba(17, 28, 49, 0.96), rgba(14, 24, 42, 0.94));
  --msg-border: rgba(36, 53, 82, 0.95);
  --msg-shadow: 0 18px 34px rgba(0, 0, 0, 0.3), 0 2px 6px rgba(0, 0, 0, 0.22);
  --user-msg-bg: linear-gradient(180deg, rgba(25, 41, 67, 0.98), rgba(18, 34, 58, 0.94));
  --user-msg-border: rgba(52, 78, 120, 0.92);
  --assistant-msg-bg: linear-gradient(180deg, rgba(16, 24, 39, 0.98), rgba(14, 20, 35, 0.94));
  --assistant-msg-border: rgba(36, 53, 82, 0.95);
  --code-bg: #f8fafc;
  --code-toolbar-bg: linear-gradient(180deg, rgba(241, 245, 249, 0.98), rgba(226, 232, 240, 0.96));
  --code-border: rgba(203, 213, 225, 0.96);
  --code-fg: #172033;
  --code-muted: #64748b;
  --code-keyword: #7c3aed;
  --code-string: #0f766e;
  --code-number: #be185d;
  --code-title: #1d4ed8;
  --code-attr: #b45309;
  --code-comment: #94a3b8;
  --code-link: #0f766e;
  --code-variable: #c2410c;
  --file-empty-bg: rgba(148, 163, 184, 0.14);
  --file-empty-border: rgba(148, 163, 184, 0.38);
  --file-empty-fg: #b8c4d8;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

body {
  display: grid;
  grid-template-columns: var(--sidebar-width) 8px 1fr;
  height: 100vh;
  overflow: hidden;
}

/* ---------- sidebar ---------- */
.sidebar {
  grid-column: 1;
  background: var(--bg-soft);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  transition: margin-left 0.25s ease, opacity 0.2s ease;
}

body.sidebar-collapsed .sidebar {
  margin-left: calc(-1 * var(--sidebar-width));
  opacity: 0;
  pointer-events: none;
}

body.sidebar-collapsed {
  grid-template-columns: 0 0 1fr;
}

.sidebar-resizer {
  grid-column: 2;
  width: 8px;
  cursor: col-resize;
  position: relative;
  background:
    linear-gradient(to right, transparent 0, transparent 2px, rgba(214, 154, 60, 0.2) 2px, rgba(214, 154, 60, 0.2) 3px, transparent 3px);
  transition: background 0.15s ease;
}

.sidebar-resizer:hover {
  background:
    linear-gradient(to right, transparent 0, transparent 1px, rgba(214, 154, 60, 0.45) 1px, rgba(214, 154, 60, 0.45) 4px, transparent 4px);
}

body.sidebar-collapsed .sidebar-resizer {
  display: none;
}

.sidebar-toggle {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  width: 30px;
  height: 30px;
  font-size: 16px;
  line-height: 1;
  color: var(--fg-dim);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
  flex-shrink: 0;
}

.sidebar-toggle:hover {
  background: var(--accent-bg);
  border-color: var(--accent);
  color: var(--accent-soft);
}

.brand {
  padding: 18px 18px 14px;
  border-bottom: 1px solid var(--border-soft);
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid rgba(127, 138, 159, 0.18);
  box-shadow: 0 8px 18px rgba(20, 25, 40, 0.08);
  background: rgba(255, 255, 255, 0.6);
}

.brand-icon {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.brand-copy {
  min-width: 0;
}

.brand-title {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.3px;
  color: var(--accent-soft);
}

.brand-sub {
  margin-top: 4px;
  font-size: 12px;
  color: var(--fg-mute);
  font-family: var(--mono);
}

.side-actions {
  padding: 12px 14px;
  display: flex;
  gap: 8px;
  border-bottom: 1px solid var(--border-soft);
}

.side-section {
  padding: 14px 14px 6px;
  border-bottom: 1px solid var(--border-soft);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-height: 0;
  flex: 1 1 0;
}

.side-section-sessions {
  flex: 0 0 auto;
}

.side-header {
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--fg-mute);
  margin-bottom: 8px;
}

.cmd-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 10px;
}

.chip {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--fg-dim);
  padding: 4px 10px;
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 11px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.chip:hover {
  border-color: var(--accent);
  color: var(--accent-soft);
  background: var(--accent-bg);
}

.session-list {
  list-style: none;
  margin: 0;
  padding: 4px 10px 12px;
  flex: 0 0 auto;
  max-height: min(40vh, 360px);
  overflow-y: auto;
}

.session-date-group {
  font-size: 11px;
  font-weight: 500;
  color: var(--fg-mute);
  padding: 14px 6px 6px;
}

.session-date-group:first-child {
  padding-top: 8px;
}

.session-item {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 8px 10px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.12s ease;
}

.session-item:hover {
  background: var(--bg-elev);
}

.session-item.active {
  background: var(--accent-bg);
}

.session-item-label {
  font-size: 13px;
  color: var(--fg-dim);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.session-item-main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.session-item-id {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--fg-mute);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.session-item.active .session-item-label,
.session-item.active .session-item-id {
  color: var(--accent);
}

.session-item.active .session-item-label {
  font-weight: 500;
}

.session-rename-input {
  width: 100%;
  border: 1px solid var(--accent);
  border-radius: 4px;
  background: #fff;
  color: var(--fg);
  font-size: 13px;
  font-family: var(--sans);
  padding: 1px 4px;
  outline: none;
  box-shadow: 0 0 0 2px rgba(214, 154, 60, 0.15);
}

.session-item-run {
  flex-shrink: 0;
  padding: 2px 6px;
  border-radius: 999px;
  background: rgba(214, 154, 60, 0.12);
  color: var(--accent-soft);
  font-size: 10px;
  line-height: 1.4;
}

.session-item-del {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--fg-mute);
  font-size: 14px;
  line-height: 1;
  cursor: pointer;
  transition: all 0.12s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  visibility: hidden;
}

.session-item:hover .session-item-del {
  visibility: visible;
}

.session-item-del:hover {
  background: #fdecec;
  color: var(--danger);
}

.side-section-files {
  padding: 0;
  flex: 1 1 0;
  min-height: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  border-bottom: none;
}

.side-header-files {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 14px 14px 8px;
  margin-bottom: 0;
  border-bottom: 1px solid var(--border-soft);
}

.side-header-meta {
  font-size: 10px;
  color: var(--fg-mute);
  letter-spacing: 0;
  text-transform: none;
}

.file-groups {
  flex: 1;
  min-height: 0;
  overflow-y: scroll;
  padding: 10px 10px 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  scrollbar-gutter: stable;
}

.file-groups::-webkit-scrollbar {
  width: 10px;
}

.file-groups::-webkit-scrollbar-thumb {
  background: rgba(139, 144, 160, 0.45);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

.file-groups::-webkit-scrollbar-track {
  background: transparent;
}

.file-empty {
  padding: 12px 10px;
  border: 1px dashed var(--file-empty-border);
  border-radius: 10px;
  color: var(--file-empty-fg);
  text-align: center;
  background: var(--file-empty-bg);
}

.file-group {
  flex: 0 0 auto;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-soft);
  overflow: hidden;
}

.file-group.current {
  border-color: rgba(214, 154, 60, 0.45);
  box-shadow: inset 0 0 0 1px rgba(214, 154, 60, 0.08);
}

.file-group-head {
  width: 100%;
  border: none;
  background: transparent;
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-rows: auto auto;
  gap: 1px 10px;
  padding: 10px 12px;
  cursor: pointer;
  text-align: left;
  transition: background 0.15s ease;
}
.file-group-head .file-group-label { grid-column: 1; grid-row: 1; }
.file-group-head .file-group-session { grid-column: 1; grid-row: 2; }
.file-group-head .file-group-count { grid-column: 2; grid-row: 1 / 3; align-self: center; }

.file-group-head:hover {
  background: var(--bg-elev);
}

.file-group-label {
  font-size: 13px;
  color: var(--fg);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
  min-width: 0;
}
.file-group-session {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--fg-mute);
}

.file-group-count {
  flex-shrink: 0;
  font-size: 11px;
  color: var(--fg-mute);
}

.file-group-body {
  padding: 0 8px 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: min(52vh, 520px);
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  scrollbar-gutter: stable;
}

.file-group-body::-webkit-scrollbar {
  width: 10px;
}

.file-group-body::-webkit-scrollbar-thumb {
  background: rgba(139, 144, 160, 0.45);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

.file-group-body::-webkit-scrollbar-track {
  background: transparent;
}

.file-group.collapsed .file-group-body {
  display: none;
}

.file-group-meta {
  padding: 0 4px;
  font-size: 10px;
  color: var(--fg-mute);
}

.file-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 9px;
  border-radius: 8px;
  background: var(--bg-elev);
  border: 1px solid transparent;
  color: var(--fg-dim);
  text-decoration: none;
  -webkit-user-drag: none;
}

.file-row.downloadable {
  cursor: pointer;
}

.file-row.downloadable:hover {
  border-color: rgba(214, 154, 60, 0.35);
  background: var(--accent-bg);
}

.file-row-icon {
  flex-shrink: 0;
  font-size: 16px;
}

.file-row-main {
  min-width: 0;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.file-row-name {
  font-size: 12px;
  color: var(--fg);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-row-path {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--fg-mute);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-row-side {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 3px;
}

.file-row-size {
  font-size: 10px;
  color: var(--fg-mute);
  font-family: var(--mono);
}

.file-row-tag {
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 999px;
  background: rgba(20, 25, 40, 0.06);
  color: var(--fg-dim);
}

.file-row.downloadable .file-row-tag {
  background: rgba(214, 154, 60, 0.18);
  color: var(--accent-soft);
}

.side-footer {
  margin-top: auto;
  padding: 12px 14px;
  border-top: 1px solid var(--border-soft);
  font-size: 11px;
  color: var(--fg-mute);
  font-family: var(--mono);
  background: var(--bg-elev);
  flex-shrink: 0;
}

.meta-row {
  display: flex;
  justify-content: space-between;
  padding: 2px 0;
}

.meta-row span:last-child {
  color: var(--fg);
}

.meta-row.auth-row {
  margin-top: 6px;
  padding-top: 6px;
  border-top: 1px dashed var(--border-soft);
  align-items: center;
}
.meta-row.auth-row #user-email {
  color: var(--fg);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 70%;
}
.btn-logout {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--fg-dim);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 999px;
  cursor: pointer;
}
.btn-logout:hover { background: rgba(220,38,38,0.1); color: #dc2626; border-color: #dc2626; }

/* ---------- main ---------- */
.main {
  grid-column: 3;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  height: 100vh;
  background: var(--bg);
  overflow: hidden;
}

/* ---------- content row ---------- */
.content-row {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  overflow: hidden;
}

.topbar {
  height: 52px;
  padding: 0 22px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-soft);
}

/* ───────── Agent 状态面板（主页显著位置） ───────── */
.agent-status {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 22px;
  border-bottom: 1px solid var(--border);
  background: transparent;
  font-size: 13px;
  transition: background 0.2s ease, border-color 0.2s ease;
  flex: 0 0 auto;
}
.agent-status.hidden { display: none; }
.agent-status-indicator {
  width: 32px;
  height: 32px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  flex-shrink: 0;
}
.agent-status-spinner {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid rgba(120, 120, 120, 0.25);
  border-top-color: #2f7bff;
  display: inline-block;
  animation: agent-status-spin 0.9s linear infinite;
}
@keyframes agent-status-spin { to { transform: rotate(360deg); } }

.agent-status-body {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
  flex: 1 1 auto;
}
.agent-status-title {
  font-weight: 600;
  font-size: 14px;
  color: var(--fg);
  line-height: 1.3;
}
.agent-status-detail {
  color: var(--fg-dim);
  font-size: 12.5px;
  line-height: 1.4;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.agent-status-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}
.agent-status-timer {
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  color: var(--fg-dim);
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
}
.agent-status-timer:empty { display: none; }
.agent-status-close {
  background: transparent;
  border: none;
  font-size: 18px;
  color: var(--fg-dim);
  cursor: pointer;
  padding: 2px 6px;
  line-height: 1;
  border-radius: 4px;
}
.agent-status-close:hover { background: rgba(127,127,127,0.15); }

.agent-status[data-level="idle"] .agent-status-spinner {
  border-color: rgba(120,120,120,0.25);
  border-top-color: #888;
  animation: none;
}

.agent-status[data-level="busy"] .agent-status-spinner,
.agent-status[data-level="streaming"] .agent-status-spinner {
  border-top-color: #2f7bff;
}
.agent-status[data-level="busy"],
.agent-status[data-level="streaming"] {
  background: linear-gradient(90deg, rgba(47,123,255,0.10), transparent);
  border-bottom-color: rgba(47,123,255,0.28);
}

.agent-status[data-level="thinking"] .agent-status-spinner { border-top-color: #8b5cf6; }
.agent-status[data-level="thinking"] {
  background: linear-gradient(90deg, rgba(139,92,246,0.10), transparent);
  border-bottom-color: rgba(139,92,246,0.28);
}

.agent-status[data-level="tool"] .agent-status-spinner { border-top-color: #f59e0b; }
.agent-status[data-level="tool"] {
  background: linear-gradient(90deg, rgba(245,158,11,0.14), transparent);
  border-bottom-color: rgba(245,158,11,0.35);
}

.agent-status[data-level="error"] .agent-status-spinner {
  border-top-color: #dc2626;
  animation: none;
}
.agent-status[data-level="error"] {
  background: linear-gradient(90deg, rgba(220,38,38,0.14), transparent);
  border-bottom-color: rgba(220,38,38,0.4);
}
.agent-status[data-level="error"] .agent-status-title { color: #dc2626; }

.topbar-left {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--fg-dim);
  font-size: 12px;
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ok);
  box-shadow: 0 0 0 3px rgba(58, 160, 95, 0.15);
}

.dot.busy {
  background: var(--accent);
  box-shadow: 0 0 0 3px rgba(214, 154, 60, 0.2);
  animation: pulse 1.2s ease-in-out infinite;
}

.dot.err {
  background: var(--danger);
  box-shadow: 0 0 0 3px rgba(209, 67, 67, 0.18);
}

@keyframes pulse {

  0%,
  100% {
    opacity: 0.55;
  }

  50% {
    opacity: 1;
  }
}

.topbar-right {
  display: flex;
  gap: 8px;
}

.pill {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--fg-dim);
  padding: 4px 10px;
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 11px;
}

.theme-toggle {
  cursor: pointer;
  transition: all 0.16s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 30px;
  padding: 0;
  position: relative;
}

.theme-toggle:hover {
  border-color: rgba(214, 154, 60, 0.45);
  background: var(--accent-bg);
  color: var(--accent-soft);
}

.theme-icon {
  position: absolute;
  font-size: 14px;
  line-height: 1;
  transition: opacity 0.18s ease, transform 0.18s ease;
}

.theme-icon-sun {
  opacity: 0;
  transform: scale(0.72) rotate(-14deg);
}

.theme-icon-moon {
  opacity: 1;
  transform: scale(1) rotate(0deg);
}

body.theme-dark .theme-icon-sun {
  opacity: 1;
  transform: scale(1) rotate(0deg);
}

body.theme-dark .theme-icon-moon {
  opacity: 0;
  transform: scale(0.72) rotate(10deg);
}

.model-pill {
  color: var(--accent-soft);
  background: var(--accent-bg);
  border-color: rgba(214, 154, 60, 0.4);
}

/* ---------- messages ---------- */
.messages-wrapper {
  flex: 1 1 auto;
  min-height: 0;
  position: relative;
  overflow: hidden;
}

.messages {
  height: 100%;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 18px 32px 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 1040px;
  margin: 0 auto;
  width: 100%;
}

.messages.intro-mode {
  overflow-y: hidden;
  overscroll-behavior: none;
}

.msg {
  width: 100%;
  padding: 14px 16px 15px;
  border-radius: 18px;
  line-height: 1.55;
  word-break: break-word;
  border: 1px solid var(--msg-border);
  background: var(--msg-bg);
  box-shadow: var(--msg-shadow);
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(4px);
  }

  to {
    opacity: 1;
    transform: none;
  }
}

.msg.user {
  align-self: flex-end;
  width: min(88%, 900px);
  background: var(--user-msg-bg);
  border-color: var(--user-msg-border);
}

.msg.assistant {
  background: var(--assistant-msg-bg);
  border-color: var(--assistant-msg-border);
}

.msg.system {
  background: transparent;
  border: 1px dashed var(--border);
  color: var(--fg-mute);
  font-family: var(--mono);
  font-size: 11px;
}

.msg-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.msg.user .msg-meta {
  justify-content: flex-end;
}

.msg .role {
  display: inline-flex;
  align-items: center;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--fg-mute);
}

.msg-copy {
  flex-shrink: 0;
  border: 1px solid rgba(31, 36, 48, 0.08);
  background: rgba(255, 255, 255, 0.78);
  color: var(--fg-dim);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 11px;
  line-height: 1.2;
  cursor: pointer;
  transition: all 0.16s ease;
}

.msg-copy:hover:not(:disabled) {
  border-color: rgba(214, 154, 60, 0.45);
  background: var(--accent-bg);
  color: var(--accent-soft);
}

.msg-copy:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.msg-copy.copied {
  border-color: rgba(58, 160, 95, 0.4);
  background: rgba(58, 160, 95, 0.12);
  color: var(--ok);
}

.msg .body code {
  background: rgba(20, 25, 40, 0.06);
  padding: 2px 5px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 12px;
}

/* ---------- rendered markdown ---------- */
.msg .body.rendered {
  white-space: normal;
  line-height: 1.5;
  color: var(--fg);
}

.msg .body.rendered h1,
.msg .body.rendered h2,
.msg .body.rendered h3,
.msg .body.rendered h4,
.msg .body.rendered h5,
.msg .body.rendered h6 {
  margin: 0 0 10px;
  line-height: 1.24;
  color: var(--fg);
}

.msg .body.rendered h1 {
  font-size: 1.26em;
}

.msg .body.rendered h2 {
  font-size: 1.14em;
}

.msg .body.rendered h3 {
  font-size: 1em;
}

.msg .body.rendered p {
  margin: 0 0 12px;
  line-height: 1.72;
}

.msg .body.rendered p:first-child {
  margin-top: 0;
}

.msg .body.rendered> :last-child,
.msg .body.rendered .stream-part> :last-child {
  margin-bottom: 0;
}

.msg .body.rendered ul,
.msg .body.rendered ol {
  margin: 0 0 12px;
  padding-left: 22px;
}

.msg .body.rendered li {
  margin: 0 0 6px;
  line-height: 1.65;
}

.msg .body.rendered li>p {
  margin: 0;
}

.msg .body.rendered blockquote {
  margin: 0 0 12px;
  padding: 10px 12px;
  border-left: 3px solid rgba(214, 154, 60, 0.9);
  background: rgba(214, 154, 60, 0.09);
  color: var(--fg-dim);
  border-radius: 0 10px 10px 0;
}

.msg .body.rendered pre {
  margin: 0 0 12px;
  padding: 12px 14px;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 12px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.5;
  color: var(--code-fg);
}

.code-block {
  margin: 0 0 12px;
  border: 1px solid var(--code-border);
  border-radius: 12px;
  overflow: hidden;
  background: var(--code-bg);
}

.code-block-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 7px 9px;
  border-bottom: 1px solid var(--code-border);
  background: var(--code-toolbar-bg);
}

.code-lang {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.8px;
  color: var(--code-muted);
}

.code-copy {
  border: 1px solid rgba(31, 36, 48, 0.08);
  background: rgba(255, 255, 255, 0.78);
  color: var(--fg-dim);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 11px;
  line-height: 1.2;
  cursor: pointer;
  transition: all 0.16s ease;
}

.code-copy:hover:not(:disabled) {
  border-color: rgba(214, 154, 60, 0.45);
  background: var(--accent-bg);
  color: var(--accent-soft);
}

.code-copy:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.code-copy.copied {
  border-color: rgba(58, 160, 95, 0.4);
  background: rgba(58, 160, 95, 0.12);
  color: var(--ok);
}

.msg .body.rendered pre code {
  background: transparent;
  padding: 0;
  border-radius: 0;
}

.msg .body.rendered .code-block pre {
  margin: 0;
  border: none;
  border-radius: 0;
  background: transparent;
}

.msg .body.rendered .code-block pre code.hljs {
  padding: 14px 16px;
  background: transparent;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--code-fg);
}

.msg .body.rendered .code-block pre code.hljs,
.msg .body.rendered .code-block pre code.hljs * {
  color: inherit;
}

.msg .body.rendered .code-block .hljs-comment,
.msg .body.rendered .code-block .hljs-quote {
  color: var(--code-comment) !important;
}

.msg .body.rendered .code-block .hljs-keyword,
.msg .body.rendered .code-block .hljs-selector-tag,
.msg .body.rendered .code-block .hljs-literal,
.msg .body.rendered .code-block .hljs-name {
  color: var(--code-keyword) !important;
}

.msg .body.rendered .code-block .hljs-string,
.msg .body.rendered .code-block .hljs-doctag,
.msg .body.rendered .code-block .hljs-regexp {
  color: var(--code-string) !important;
}

.msg .body.rendered .code-block .hljs-number,
.msg .body.rendered .code-block .hljs-symbol,
.msg .body.rendered .code-block .hljs-bullet {
  color: var(--code-number) !important;
}

.msg .body.rendered .code-block .hljs-title,
.msg .body.rendered .code-block .hljs-title.class_,
.msg .body.rendered .code-block .hljs-title.function_ {
  color: var(--code-title) !important;
}

.msg .body.rendered .code-block .hljs-attr,
.msg .body.rendered .code-block .hljs-attribute,
.msg .body.rendered .code-block .hljs-property,
.msg .body.rendered .code-block .hljs-params {
  color: var(--code-attr) !important;
}

.msg .body.rendered .code-block .hljs-variable,
.msg .body.rendered .code-block .hljs-template-variable,
.msg .body.rendered .code-block .hljs-type {
  color: var(--code-variable) !important;
}

.msg .body.rendered .code-block .hljs-link,
.msg .body.rendered .code-block .hljs-selector-id,
.msg .body.rendered .code-block .hljs-selector-class {
  color: var(--code-link) !important;
}

.msg .body.rendered table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 12px;
  font-size: 12.5px;
  overflow: hidden;
  border-radius: 12px;
}

.msg .body.rendered th,
.msg .body.rendered td {
  border: 1px solid var(--border);
  padding: 6px 10px;
  text-align: left;
}

.msg .body.rendered th {
  background: #eef2f8;
  font-weight: 600;
  white-space: nowrap;
}

.msg .body.rendered tr:nth-child(even) td {
  background: rgba(0, 0, 0, 0.015);
}

.msg .body.rendered hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 12px 0;
}

.msg .body.rendered a {
  color: var(--accent-soft);
  text-decoration: underline;
}

.msg .body.rendered img {
  max-width: 100%;
  border-radius: 6px;
}

/* ---------- scroll to bottom ---------- */
.scroll-btn {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--fg-dim);
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.10);
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.scroll-btn:hover {
  background: var(--accent-bg);
  border-color: var(--accent);
  color: var(--accent-soft);
}

.scroll-btn.hidden {
  opacity: 0;
  pointer-events: none;
}

/* ---------- streaming ---------- */
.msg.assistant .stream-part {
  display: block;
  white-space: pre-wrap;
  word-wrap: break-word;
}

.msg.assistant .body.rendered .stream-part {
  white-space: normal;
}

.msg.assistant .thinking-group.stream-part {
  white-space: normal;
}

.msg.assistant .stream-part+.stream-part {
  margin-top: 8px;
}

.msg .cursor {
  display: inline-block;
  width: 7px;
  height: 1em;
  vertical-align: text-bottom;
  background: var(--accent);
  margin-left: 2px;
  animation: blink 1s steps(2, start) infinite;
}

@keyframes blink {
  to {
    visibility: hidden;
  }
}

/* ---------- thinking group ---------- */
.thinking-group {
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  background: var(--bg-elev);
}

.thinking-head {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 5px 10px;
  cursor: pointer;
  user-select: none;
  font-size: 12px;
  color: var(--fg-dim);
  transition: background 0.15s ease;
}

.thinking-head:hover {
  background: rgba(0, 0, 0, 0.02);
}

.thinking-icon {
  font-size: 14px;
  color: var(--accent);
}

.thinking-label {
  font-weight: 500;
}

.thinking-count {
  color: var(--fg-mute);
  font-size: 11px;
}

.thinking-head .caret {
  margin-left: auto;
  width: 12px;
  text-align: center;
  color: var(--fg-mute);
  font-size: 13px;
  transition: transform 0.15s ease;
}

.thinking-group.collapsed .caret {
  transform: rotate(-90deg);
}

.thinking-group.collapsed .thinking-body {
  display: none;
}

.thinking-body {
  padding: 2px 6px 4px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.tool-block {
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-elev);
  overflow: hidden;
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.3;
}

.tool-block .tool-head {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 3px 8px;
  background: var(--accent-bg);
  color: var(--accent-soft);
  border-bottom: 1px solid var(--border);
  user-select: none;
}

.tool-block .tool-head .badge {
  background: var(--accent);
  color: #fff;
  border-radius: 3px;
  padding: 1px 6px;
  font-size: 9px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.tool-block .tool-head .tool-name {
  font-weight: 600;
}

.tool-block .tool-head .tool-status {
  margin-left: auto;
  color: var(--fg-mute);
  font-size: 10px;
  font-weight: 400;
}

.reasoning-block {
  background: #fafafa;
  border: 1px dashed var(--border);
  border-radius: 4px;
  padding: 6px 10px;
  margin: 4px 0;
  font-size: 12px;
  color: var(--fg-dim);
  line-height: 1.55;
}

.reasoning-block .reasoning-label {
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 1px;
  color: var(--accent);
  margin-bottom: 3px;
}

.reasoning-block .reasoning-text {
  white-space: pre-wrap;
  word-wrap: break-word;
  font-family: var(--sans);
}

.tool-block .tool-body {
  padding: 3px 8px 4px;
}

.tool-block .tool-body .tool-label {
  font-size: 9px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--fg-mute);
  margin: 0;
}

.tool-block .tool-body pre {
  margin: 1px 0 3px;
  padding: 4px 8px;
  background: #fff;
  border: 1px solid var(--border-soft);
  border-radius: 4px;
  max-height: 200px;
  overflow: auto;
  white-space: pre-wrap;
  word-wrap: break-word;
  color: var(--fg-dim);
  line-height: 1.3;
}

.tool-block .tool-body pre:last-child {
  margin-bottom: 0;
}

.tool-block.error .tool-head {
  background: #fdecec;
  color: var(--danger);
  border-bottom-color: #f5c7c7;
}

.tool-block.error .tool-head .badge {
  background: var(--danger);
}

.turn-divider {
  align-self: stretch;
  text-align: center;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--fg-mute);
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 2px 0;
  opacity: 0.7;
}

.empty {
  width: 100%;
  margin: 0 0 10px;
  padding: 4px 0 10px;
  color: var(--fg-mute);
  flex: 0 0 auto;
  height: calc(100% - 10px);
  min-height: calc(100% - 10px);
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.empty-hero {
  min-height: 190px;
  border-radius: 28px;
  border: 1px solid rgba(214, 154, 60, 0.18);
  background:
    radial-gradient(circle at top left, rgba(214, 154, 60, 0.16), transparent 34%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(246, 248, 252, 0.92));
  box-shadow: 0 18px 42px rgba(18, 24, 36, 0.06), inset 0 1px 0 rgba(255, 255, 255, 0.78);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 22px;
  padding: 28px 30px;
  margin-bottom: 16px;
  flex: 0 0 auto;
}

body.theme-dark .empty-hero {
  background:
    radial-gradient(circle at top left, rgba(214, 154, 60, 0.12), transparent 32%),
    linear-gradient(180deg, rgba(18, 29, 48, 0.96), rgba(11, 18, 30, 0.96));
  border-color: rgba(214, 154, 60, 0.16);
  box-shadow: 0 20px 44px rgba(0, 0, 0, 0.26), inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.empty-welcome {
  text-align: center;
}

.empty-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 5px 12px;
  border-radius: 999px;
  background: var(--accent-bg);
  border: 1px solid rgba(214, 154, 60, 0.28);
  color: var(--accent-soft);
  font-size: 11px;
  letter-spacing: 1.1px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.empty-title {
  font-size: 36px;
  line-height: 1.08;
  color: var(--fg);
  margin-bottom: 12px;
  font-weight: 600;
}

.empty-sub {
  max-width: none;
  margin: 0 auto;
  font-size: clamp(13px, 1.55vw, 15px);
  line-height: 1.7;
  color: var(--fg-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.empty-hero-rail {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.empty-hero-chip {
  padding: 14px 16px;
  border-radius: 18px;
  border: 1px solid rgba(214, 154, 60, 0.16);
  background: rgba(214, 154, 60, 0.08);
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px;
}

.empty-hero-chip span {
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-dim);
}

.empty-hero-chip strong {
  font-family: var(--mono);
  font-size: 24px;
  line-height: 1;
  color: var(--fg);
  font-weight: 600;
}

.empty-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-auto-rows: minmax(0, 1fr);
  gap: 14px;
  align-items: stretch;
  flex: 1 1 auto;
  min-height: 0;
}

.empty-grid.compact-layout {
  align-items: start;
}

.empty-card {
  padding: 18px;
  border-radius: 18px;
  border: 1px solid var(--border);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(246, 248, 252, 0.94));
  box-shadow: 0 20px 44px rgba(20, 25, 40, 0.05), 0 3px 10px rgba(20, 25, 40, 0.04);
  position: relative;
  overflow: hidden;
  min-height: 0;
  height: 100%;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.empty-grid.compact-layout .empty-card {
  height: auto;
  min-height: 0;
  align-self: start;
}

.empty-grid.compact-layout .empty-card:not(.collapsed) .empty-card-body {
  max-height: min(42vh, 520px);
}

body.theme-dark .empty-card {
  background:
    linear-gradient(180deg, rgba(18, 29, 48, 0.96), rgba(14, 22, 36, 0.94));
  border-color: rgba(48, 67, 100, 0.9);
  box-shadow: 0 20px 44px rgba(0, 0, 0, 0.26), 0 3px 10px rgba(0, 0, 0, 0.2);
}

.empty-card::before {
  content: "";
  position: absolute;
  inset: 0 auto auto 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, rgba(214, 154, 60, 0.68), rgba(214, 154, 60, 0), rgba(214, 154, 60, 0.18));
}

.empty-card-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 8px;
}

.empty-card-head-actions {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.empty-card-title {
  font-size: 18px;
  color: var(--fg);
  font-weight: 600;
  letter-spacing: 0.2px;
}

.empty-card-meta {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--fg-mute);
}

.empty-card-sub {
  font-size: 13px;
  color: var(--fg-dim);
  line-height: 1.65;
  margin-bottom: 14px;
}

.empty-card-body {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding-right: 4px;
  scrollbar-gutter: stable;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
}

.empty-card-body::-webkit-scrollbar {
  width: 8px;
}

.empty-card-body::-webkit-scrollbar-thumb {
  background: rgba(139, 144, 160, 0.35);
  border-radius: 999px;
}

.empty-card-body::-webkit-scrollbar-track {
  background: transparent;
}

.empty-card.collapsed .empty-card-sub,
.empty-card.collapsed .empty-card-body {
  display: none;
}

.empty-command-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.empty-tool-grid {
  display: grid;
  gap: 8px;
}

.empty-skill-list {
  display: grid;
  gap: 8px;
}

.empty-item {
  min-width: 0;
  padding: 12px 13px;
  border-radius: 14px;
  background: rgba(20, 25, 40, 0.05);
  border: 1px solid rgba(127, 138, 159, 0.14);
  transition: border-color 0.16s ease, background 0.16s ease, transform 0.16s ease;
}

body.theme-dark .empty-item {
  background: rgba(255, 255, 255, 0.035);
  border-color: rgba(148, 163, 184, 0.14);
}

.empty-item:hover,
.empty-item[open] {
  border-color: rgba(214, 154, 60, 0.26);
  background: rgba(214, 154, 60, 0.08);
}

.empty-item-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  min-width: 0;
  width: 100%;
}

.empty-item-summary::-webkit-details-marker {
  display: none;
}

.empty-item-name {
  flex: 1 1 auto;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--fg);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}

.empty-skill-copy {
  cursor: copy;
}

.empty-skill-copy:hover {
  color: var(--accent-soft);
}

.empty-item-toggle {
  flex: 0 0 auto;
  font-size: 11px;
  color: var(--accent-soft);
  white-space: nowrap;
}

.empty-item[open] .empty-item-toggle::before {
  content: "收起";
}

.empty-item:not([open]) .empty-item-toggle::before {
  content: "展开";
}

.empty-item-body {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed rgba(127, 138, 159, 0.18);
}

.empty-item-desc {
  font-size: 12px;
  line-height: 1.58;
  color: var(--fg-dim);
  margin: 0;
}

.empty-item-action {
  margin-top: 10px;
  border: 1px solid rgba(214, 154, 60, 0.2);
  background: rgba(214, 154, 60, 0.1);
  color: var(--accent-soft);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 11px;
  cursor: pointer;
  transition: all 0.16s ease;
}

.empty-item-action:hover {
  border-color: rgba(214, 154, 60, 0.42);
  background: rgba(214, 154, 60, 0.16);
}

.empty-card-toggle {
  border: 1px solid rgba(214, 154, 60, 0.18);
  background: rgba(214, 154, 60, 0.08);
  color: var(--accent-soft);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 11px;
  cursor: pointer;
  transition: all 0.16s ease;
}

.empty-card-toggle:hover {
  border-color: rgba(214, 154, 60, 0.4);
  background: rgba(214, 154, 60, 0.16);
}

.empty-note {
  font-size: 12px;
  color: var(--fg-mute);
  line-height: 1.5;
}

@media (max-width: 1120px) {
  .empty-hero-rail,
  .empty-grid {
    grid-template-columns: 1fr;
  }

  .empty {
    min-height: auto;
  }
}

@media (max-width: 720px) {
  .empty-title {
    font-size: 28px;
  }

  .empty-card {
    padding: 14px;
  }

  .empty-hero {
    padding: 22px 18px;
  }

  .empty-sub {
    white-space: normal;
  }
}

/* ---------- chat navigator ---------- */
.chat-nav {
  width: 220px;
  flex-shrink: 0;
  border-left: 1px solid var(--border);
  background: var(--bg-soft);
  overflow: visible;
  padding: 0;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: width 0.2s ease, border-color 0.2s ease;
}

.chat-nav.collapsed {
  width: 0;
  border-left-color: transparent;
}

.chat-nav-cmds {
  padding: 12px 12px 8px;
  border-bottom: 1px solid var(--border-soft);
}

.chat-nav.collapsed .chat-nav-cmds {
  display: none;
}

.chat-nav-list {
  overflow-y: auto;
  padding: 10px 10px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.chat-nav.collapsed .chat-nav-list {
  display: none;
}

.nav-toggle {
  position: absolute;
  left: -18px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 11;
  width: 18px;
  height: 48px;
  border: 1px solid var(--border);
  border-right: none;
  border-radius: 6px 0 0 6px;
  background: var(--bg-soft);
  color: var(--fg-mute);
  font-size: 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
  padding: 0;
}

.nav-toggle:hover {
  background: var(--accent-bg);
  color: var(--accent-soft);
}

.chat-nav-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 8px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
  color: var(--fg-dim);
  border: none;
  background: transparent;
  text-align: left;
  line-height: 1.4;
  transition: all 0.12s ease;
  width: 100%;
}

.chat-nav-item:hover {
  background: var(--bg-elev);
}

.chat-nav-item.active {
  color: var(--accent-soft);
  font-weight: 600;
}

.chat-nav-item .nav-text {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chat-nav-item .nav-indicator {
  flex-shrink: 0;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--fg-mute);
  opacity: 0.4;
}

.chat-nav-item.active .nav-indicator {
  background: var(--accent);
  opacity: 1;
}

@media (max-width: 1100px) {
  .chat-nav {
    display: none;
  }
}

/* ---------- composer ---------- */
.composer {
  border-top: 1px solid var(--border);
  padding: 14px 22px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: var(--bg-soft);
}
.composer-row {
  display: flex;
  gap: 10px;
  align-items: flex-end;
}

.composer textarea {
  flex: 1;
  resize: none;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--fg);
  padding: 12px 14px;
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.5;
  max-height: 240px;
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.composer textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(214, 154, 60, 0.15);
}

.btn {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  color: var(--fg-dim);
  padding: 9px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 13px;
  font-family: var(--sans);
  transition: all 0.15s ease;
}

.btn:hover {
  border-color: var(--accent);
  color: var(--fg);
  background: var(--accent-bg);
}

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #ffffff;
  font-weight: 600;
}

.btn.primary:hover {
  background: var(--accent-soft);
  border-color: var(--accent-soft);
  color: #ffffff;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ---------- file upload / attach ---------- */
.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  padding: 0;
  flex-shrink: 0;
  border-radius: 50%;
}
.icon-btn svg {
  width: 18px;
  height: 18px;
}

.file-preview-bar {
  display: none;
  flex-wrap: wrap;
  gap: 8px;
}
.file-preview-bar:not(:empty) {
  display: flex;
}

.file-preview-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 12px;
  color: var(--fg-dim);
  max-width: 200px;
  position: relative;
}
.file-preview-item .fp-icon { font-size: 16px; flex-shrink: 0; }
.file-preview-item .fp-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
  min-width: 0;
}
.file-preview-item .fp-size {
  font-size: 11px;
  color: var(--fg-mute);
  flex-shrink: 0;
}
.file-preview-item .fp-remove {
  position: absolute;
  top: -6px;
  right: -6px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--fg-mute);
  color: #fff;
  border: none;
  font-size: 11px;
  line-height: 18px;
  text-align: center;
  cursor: pointer;
  padding: 0;
  opacity: 0;
  transition: opacity 0.15s;
}
.file-preview-item:hover .fp-remove { opacity: 1; }
.file-preview-item .fp-thumb {
  width: 32px;
  height: 32px;
  border-radius: 4px;
  object-fit: cover;
  flex-shrink: 0;
}

.composer.drag-over {
  border-color: var(--accent);
  background: var(--accent-bg);
}

/* ---------- file download button ---------- */
.file-download {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  margin: 6px 0;
  background: var(--accent-bg);
  border: 1px solid rgba(214, 154, 60, 0.35);
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  color: var(--accent-soft);
  font-size: 13px;
  font-family: var(--sans);
  transition: all 0.15s ease;
}

.file-download:hover {
  background: rgba(214, 154, 60, 0.2);
  border-color: var(--accent);
  color: var(--accent-soft);
  text-decoration: none;
}

.file-download .file-icon {
  font-size: 18px;
  flex-shrink: 0;
}

.file-download .file-info {
  display: flex;
  flex-direction: column;
  gap: 1px;
  min-width: 0;
}

.file-download .file-name {
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-download .file-meta {
  font-size: 11px;
  color: var(--fg-mute);
}

/* ---------- scrollbar ---------- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: #d8dce4;
  border-radius: 8px;
}

::-webkit-scrollbar-thumb:hover {
  background: #c3c8d2;
}

@media (max-width: 760px) {
  body {
    grid-template-columns: 1fr;
  }

  .sidebar {
    display: none;
  }

  .sidebar-resizer {
    display: none;
  }
}