frontend/static/app.css

:root {
  --bg: #ffffff;
  --bar: #f5f5f5;
  --border: #e8e8e8;
  --panel: rgba(255, 255, 255, 0.82);
  --panel-strong: rgba(255, 255, 255, 0.96);
  --hover: #f7f7f7;
  --text: #171717;
  --muted: #747474;
  --accent-start: #1a1a1a;
  --accent-end: #333333;
  --accent-text: #ffffff;
  --glow-rgb: 0, 0, 0;
  --danger: #b42318;
  --ok: #1f7a42;
  --warn: #9a6700;
  --shadow: 0 18px 70px rgba(0, 0, 0, 0.08);
  --surface-shadow: 0 14px 38px rgba(var(--glow-rgb), 0.15), 0 3px 10px rgba(0, 0, 0, 0.08);
}

[data-theme="yellow"] {
  --bg: #faf8f4;
  --bar: #f0ebe1;
  --border: #e5ddd0;
  --panel: rgba(255, 252, 246, 0.84);
  --panel-strong: rgba(255, 252, 246, 0.96);
  --hover: #f0ece4;
  --text: #2f2113;
  --muted: #8a7055;
  --accent-start: #1c1208;
  --accent-end: #3a2410;
  --accent-text: #ffffff;
  --glow-rgb: 180, 128, 40;
}

[data-theme="blue"] {
  --bg: #f3f5f8;
  --bar: #e3e8ef;
  --border: #d3dae3;
  --panel: rgba(248, 251, 255, 0.84);
  --panel-strong: rgba(248, 251, 255, 0.96);
  --hover: #e8eef5;
  --text: #172f4a;
  --muted: #6a8aaa;
  --accent-start: #1a3654;
  --accent-end: #1e4a7a;
  --accent-text: #ffffff;
  --glow-rgb: 38, 88, 155;
}

[data-theme="dark"] {
  --bg: #111110;
  --bar: #1c1c1a;
  --border: #2e2e2b;
  --panel: rgba(28, 28, 26, 0.86);
  --panel-strong: rgba(28, 28, 26, 0.98);
  --hover: #242420;
  --text: #e8e6df;
  --muted: #8a8a80;
  --accent-start: #e8e6df;
  --accent-end: #d0cec7;
  --accent-text: #111110;
  --glow-rgb: 220, 210, 180;
  --danger: #ffb4a9;
  --ok: #9de8b5;
  --warn: #f7d36f;
  --shadow: 0 18px 70px rgba(0, 0, 0, 0.34);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: "IBM Plex Sans", "Aptos", "Segoe UI Variable", "Noto Sans CJK SC", "Microsoft YaHei", "PingFang SC", sans-serif;
  transition: background 0.3s ease, color 0.3s ease;
}

button,
input,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

.chat-shell {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr) auto;
  width: min(980px, 100%);
  height: 100vh;
  height: 100dvh;
  min-height: 0;
  overflow: hidden;
  margin: 0 auto;
  padding: 14px 16px 18px;
}

.chat-shell > * {
  min-height: 0;
}

.topbar,
.workspace-strip,
.composer {
  border: 1px solid var(--border);
  background: var(--panel);
  backdrop-filter: blur(18px);
  box-shadow: var(--shadow);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 8;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-radius: 22px;
  padding: 10px 12px;
  background: var(--panel-strong);
  box-shadow: var(--surface-shadow);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.brand strong {
  display: block;
  letter-spacing: -0.02em;
}

.logo {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  color: var(--accent-text);
  font-size: 0.82rem;
  font-weight: 900;
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 2px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
}

.status.running::before {
  content: "";
  width: 10px;
  height: 10px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.82s linear infinite;
}

.status.running {
  color: var(--warn);
}

.status.done {
  color: var(--ok);
}

.status.error {
  color: var(--danger);
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.plain,
.send-button,
.icon-button,
.model-select {
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--panel-strong);
  color: var(--text);
  font-weight: 850;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.plain {
  padding: 8px 12px;
}

.model-dropdown {
  position: relative;
}

.model-select {
  min-width: 150px;
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 12px;
  text-align: left;
  white-space: nowrap;
}

.model-select-caret {
  width: 7px;
  height: 7px;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: translateY(-2px) rotate(45deg);
  transition: transform 0.18s ease;
}

.model-dropdown.open .model-select-caret {
  transform: translateY(2px) rotate(225deg);
}

.model-options {
  position: fixed;
  top: var(--model-options-top, 64px);
  right: var(--model-options-right, 16px);
  z-index: 80;
  display: grid;
  gap: 4px;
  min-width: 220px;
  padding: 6px;
  border: 1px solid rgba(var(--glow-rgb), 0.18);
  border-radius: 18px;
  background: var(--panel-strong);
  box-shadow: 0 22px 70px rgba(0, 0, 0, 0.16);
  opacity: 0;
  pointer-events: none;
  transform: translateY(-6px) scale(0.98);
  transform-origin: top right;
  transition: opacity 0.16s ease, transform 0.16s ease;
}

.model-options.open {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0) scale(1);
}

.model-option {
  border: 0;
  border-radius: 12px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font: inherit;
  font-weight: 850;
  padding: 9px 12px;
  text-align: left;
  white-space: nowrap;
}

.model-option:hover,
.model-option:focus-visible,
.model-option.selected {
  background: rgba(var(--glow-rgb), 0.1);
}

.model-option.selected::after {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 999px;
  background: currentColor;
  opacity: 0.72;
}

.plain:hover,
.icon-button:hover,
.model-select:hover:not(:disabled),
.model-select:focus-visible {
  border-color: rgba(var(--glow-rgb), 0.38);
  transform: translateY(-1px);
}

.model-select:disabled {
  cursor: not-allowed;
  opacity: 0.58;
}

.workspace-strip {
  position: sticky;
  top: 66px;
  z-index: 8;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 10px;
  border-radius: 18px;
  padding: 9px 12px;
  background: var(--panel-strong);
  box-shadow: var(--surface-shadow);
}

.workspace-strip input {
  display: none;
}

.workspace-strip span {
  display: block;
  min-width: 0;
  color: var(--muted);
  font-size: 0.82rem;
  overflow-wrap: anywhere;
  word-break: break-word;
  white-space: normal;
}

.workspace-strip.empty {
  border-color: rgba(245, 158, 11, 0.34);
  background:
    linear-gradient(135deg, rgba(245, 158, 11, 0.09), transparent 58%),
    var(--panel);
}

.workspace-strip.empty span {
  color: var(--text);
}

.workspace-strip.error {
  border-color: rgba(248, 113, 113, 0.36);
  background:
    linear-gradient(135deg, rgba(248, 113, 113, 0.1), transparent 58%),
    var(--panel);
}

.workspace-strip.error span {
  color: var(--text);
}

.workspace-strip.busy {
  border-color: rgba(var(--glow-rgb), 0.34);
}

.download-workspace {
  flex: 0 0 auto;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--panel-strong);
  color: var(--text);
  font-size: 0.78rem;
  font-weight: 850;
  padding: 7px 11px;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.download-workspace:hover:not(:disabled),
.download-workspace:focus-visible {
  border-color: rgba(var(--glow-rgb), 0.38);
  transform: translateY(-1px);
}

.messages {
  display: flex;
  flex-direction: column;
  flex: 1 1 auto;
  gap: 14px;
  height: 100%;
  min-height: 0;
  min-width: 0;
  max-height: 100%;
  overflow-x: hidden;
  overflow-y: scroll;
  overscroll-behavior: contain;
  padding: 24px 4px 18px;
  scrollbar-gutter: stable;
  -webkit-overflow-scrolling: touch;
}

.messages::-webkit-scrollbar {
  width: 10px;
}

.messages::-webkit-scrollbar-thumb {
  border: 3px solid transparent;
  border-radius: 999px;
  background: rgba(var(--glow-rgb), 0.24);
  background-clip: padding-box;
}

.welcome {
  margin: auto;
  max-width: 650px;
  text-align: center;
}

.welcome h1 {
  margin: 0;
  font-size: clamp(2.2rem, 6vw, 4.7rem);
  line-height: 0.94;
  letter-spacing: -0.055em;
}

.welcome p {
  margin: 18px auto 0;
  max-width: 520px;
  color: var(--muted);
  line-height: 1.6;
}

.message,
.event {
  flex: 0 0 auto;
  border: 1px solid var(--border);
  border-radius: 22px;
  background: var(--panel);
  backdrop-filter: blur(18px);
  box-shadow: 0 10px 34px rgba(0, 0, 0, 0.05);
  overflow: hidden;
}

.message {
  max-width: min(760px, 92%);
}

.event {
  width: min(760px, 92%);
}

.message.user {
  align-self: flex-end;
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  color: var(--accent-text);
}

.message.assistant,
.event {
  align-self: flex-start;
}

.message-body {
  min-width: 0;
  max-width: 100%;
  padding: 14px 16px;
}

.event-body {
  max-height: none;
  overflow: hidden;
  transition: max-height 0.24s ease;
}

.event-body-inner {
  min-width: 0;
  max-width: 100%;
  padding: 14px 16px;
}

.event.collapsed .event-body {
  max-height: 220px;
}

.event.can-collapse.collapsed .event-body-inner {
  position: relative;
  overflow: hidden;
}

.event.can-collapse.collapsed .event-body-inner::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 60px;
  background: linear-gradient(to bottom, transparent, var(--panel-strong));
  pointer-events: none;
}

.event.can-collapse {
  cursor: pointer;
}

.event.latest {
  cursor: default;
}

.event:not(.can-collapse) .event-toggle {
  display: none;
}

.message-body pre,
.event-body pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
  font-size: 0.86rem;
  line-height: 1.5;
}

.markdown-body {
  min-width: 0;
  max-width: 100%;
  overflow-wrap: anywhere;
  line-height: 1.6;
  word-break: break-word;
}

.markdown-body .katex {
  font-size: 1.02em;
}

.markdown-body .katex-display {
  margin: 0.85rem 0;
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 0.1rem;
}

.markdown-body > *:first-child {
  margin-top: 0;
}

.markdown-body > *:last-child {
  margin-bottom: 0;
}

.markdown-body p,
.markdown-body ul,
.markdown-body ol,
.markdown-body blockquote,
.markdown-body table,
.markdown-body pre {
  margin: 0 0 0.8rem;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
  margin: 0 0 0.65rem;
  line-height: 1.2;
}

.markdown-body ul,
.markdown-body ol {
  padding-left: 1.35rem;
}

.markdown-body code {
  padding: 0.1rem 0.28rem;
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.08);
  font-family: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
  font-size: 0.88em;
}

.markdown-body pre {
  padding: 12px;
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.08);
  overflow-x: auto;
}

.markdown-body pre code {
  padding: 0;
  background: transparent;
}

.markdown-body blockquote {
  padding-left: 0.85rem;
  border-left: 3px solid rgba(var(--glow-rgb), 0.35);
  color: var(--muted);
}

.markdown-body a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.markdown-body img {
  display: block;
  width: auto;
  max-width: 100%;
  height: auto;
  margin: 0.65rem 0;
  border-radius: 14px;
  object-fit: contain;
}

.mermaid-chart {
  max-width: 100%;
  margin: 0.85rem 0;
  overflow-x: auto;
}

.mermaid-chart svg {
  max-width: 100%;
  height: auto;
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border-radius: 14px;
}

.markdown-body th,
.markdown-body td {
  padding: 8px 10px;
  border: 1px solid rgba(0, 0, 0, 0.12);
  text-align: left;
  vertical-align: top;
}

.message-images {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}

.message-image {
  max-width: 180px;
  max-height: 180px;
  border-radius: 16px;
  object-fit: cover;
  border: 1px solid rgba(255, 255, 255, 0.24);
}

.event-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
}

.event-title {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-weight: 900;
}

.event-toggle {
  flex: 0 0 auto;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--panel-strong);
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 850;
  padding: 5px 9px;
}

.event.latest .event-toggle {
  display: none;
}

.event:not(.collapsed) .event-toggle::after {
  content: "collapse";
}

.event.collapsed .event-toggle::after {
  content: "expand";
}

.badge {
  border-radius: 999px;
  background: rgba(var(--glow-rgb), 0.11);
  color: var(--text);
  font-size: 0.72rem;
  font-weight: 850;
  padding: 4px 8px;
}

.tool-grid {
  display: grid;
  gap: 10px;
  margin-top: 10px;
}

.tool-call {
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 11px;
  background: color-mix(in srgb, var(--hover), transparent 28%);
}

.tool-name {
  margin-bottom: 8px;
  font-weight: 900;
}

.error-text {
  color: var(--danger);
}

.muted-text {
  color: var(--muted);
}

.composer textarea {
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
}

.composer-wrap {
  position: sticky;
  bottom: 0;
  z-index: 4;
  display: grid;
  gap: 8px;
}

.composer {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  border-radius: 26px;
  padding: 11px;
  background: var(--panel-strong);
  box-shadow: var(--surface-shadow);
}

.composer.dragover {
  border-color: rgba(var(--glow-rgb), 0.44);
  box-shadow: 0 0 0 5px rgba(var(--glow-rgb), 0.09), var(--shadow);
}

.composer textarea {
  flex: 1;
  max-height: 180px;
  min-height: 30px;
  resize: none;
  line-height: 1.5;
  padding: 7px 0;
}

.icon-button,
.send-button {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  height: 38px;
  min-width: 38px;
}

.icon-button {
  font-size: 1.35rem;
  line-height: 1;
}

.send-button {
  padding: 0 16px;
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  color: var(--accent-text);
}

.send-button.is-running {
  display: flex;
  align-items: center;
  justify-content: center;
}

.send-button.is-running::before {
  content: "";
  width: 12px;
  height: 12px;
  margin-right: 8px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.82s linear infinite;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.58;
  transform: none;
}

#imageInput {
  display: none;
}

.image-preview {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0 8px;
}

.image-chip {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 240px;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 5px 10px 5px 5px;
  background: var(--panel);
  color: var(--text);
}

.image-chip img {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  object-fit: cover;
}

.image-chip span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 0.82rem;
}

.composer-hint {
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
  text-align: center;
}

#theme-switcher {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 20;
  display: flex;
  gap: 9px;
  padding: 9px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bar);
  box-shadow: 0 12px 34px rgba(0, 0, 0, 0.12);
}

.theme-dot {
  width: 21px;
  height: 21px;
  border: 1.5px solid transparent;
  border-radius: 50%;
  padding: 0;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.theme-dot[data-theme="white"] {
  background: #ffffff;
  border-color: #c8c8c8;
}

.theme-dot[data-theme="yellow"] {
  background: #e8d5a0;
  border-color: #c4a060;
}

.theme-dot[data-theme="blue"] {
  background: #a8c4e8;
  border-color: #5e8ec8;
}

.theme-dot[data-theme="dark"] {
  background: #2a2a26;
  border-color: #585852;
}

.theme-dot.active {
  box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--border);
  transform: scale(1.08);
}

.space-links {
  position: fixed;
  left: 22px;
  bottom: 22px;
  z-index: 20;
  display: flex;
  gap: 9px;
  padding: 9px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bar);
  box-shadow: 0 12px 34px rgba(0, 0, 0, 0.12);
}

.space-links a {
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  transition: background 0.18s ease, color 0.18s ease, transform 0.18s ease;
}

.space-links a:hover {
  background: rgba(var(--glow-rgb), 0.12);
  color: var(--accent-start);
  transform: translateY(-1px);
}

.space-links svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 720px) {
  .chat-shell {
    padding: 10px;
  }

  .topbar,
  .workspace-strip {
    grid-template-columns: 1fr;
  }

  .topbar {
    align-items: flex-start;
  }

  .workspace-strip {
    align-items: stretch;
    flex-direction: column;
  }

  .workspace-strip span {
    max-width: none;
  }

  .download-workspace {
    width: 100%;
  }

  .message,
  .event {
    max-width: 96%;
  }

  #theme-switcher {
    right: 12px;
    bottom: 12px;
  }

  .space-links {
    left: 12px;
    bottom: 12px;
  }
}