:root {
  --sidebar-width: 17.5rem;
  --column-width: 47.5rem;
  --radius-card: 1.5rem;
  --radius-bubble: 1.25rem;
  --icon-hit: 2.25rem;
  --transition-ui: var(--duration-fast) var(--easing-standard);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  -webkit-text-size-adjust: 100%;
  height: 100%;
}

body {
  margin: 0;
  height: 100%;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--text-body);
  font-weight: var(--weight-regular);
  line-height: 1.55;
  overflow-wrap: break-word;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

#app {
  height: 100%;
}

button,
input,
textarea {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  background: none;
  border: 0;
  padding: 0;
}

button:disabled {
  cursor: default;
}

a {
  color: var(--color-accent-text);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

a:hover {
  color: var(--color-accent-text-hover);
}

:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -4rem;
  z-index: 50;
  padding: var(--space-2) var(--space-4);
  background: var(--color-surface);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  color: var(--color-text);
}

.skip-link:focus {
  top: var(--space-3);
}

.icon {
  width: 1.25rem;
  height: 1.25rem;
  flex: none;
}

.icon--small {
  width: 1rem;
  height: 1rem;
}

.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--icon-hit);
  height: var(--icon-hit);
  flex: none;
  border-radius: var(--radius-pill);
  color: var(--color-text-secondary);
  transition: background var(--transition-ui), color var(--transition-ui);
}

.icon-button:hover {
  background: var(--color-surface-hover);
  color: var(--color-text);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-sans);
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  white-space: nowrap;
}

.brand--large {
  font-size: 2rem;
}

.app {
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  height: 100dvh;
  overflow: hidden;
}

.app.is-collapsed {
  grid-template-columns: 0 minmax(0, 1fr);
}

.app.is-collapsed .sidebar {
  display: none;
}

.scrim {
  display: none;
}

.sidebar {
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
  padding: var(--space-3);
  gap: var(--space-2);
  background: var(--color-surface);
  border-right: var(--border-hairline) solid var(--color-border);
}

.sidebar__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--target-min);
  padding-left: var(--space-2);
}

.sidebar__new {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  min-height: var(--target-min);
  padding: 0 var(--space-3);
  border-radius: var(--radius-md);
  color: var(--color-accent-text);
  font-weight: var(--weight-title);
  text-align: left;
  transition: background var(--transition-ui);
}

.sidebar__new:hover {
  background: var(--color-surface-hover);
}

.sidebar__search {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-height: var(--target-min);
  padding: 0 var(--space-3);
  background: var(--color-input-bg);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  color: var(--color-text-secondary);
}

.sidebar__search:focus-within {
  border-color: var(--color-focus);
  box-shadow: 0 0 0 1px var(--color-focus);
}

.sidebar__search-field {
  flex: 1;
  min-width: 0;
  background: none;
  border: 0;
  outline: none;
  color: var(--color-text);
}

.sidebar__search-field::placeholder {
  color: var(--color-text-secondary);
}

.sidebar__title {
  margin: var(--space-3) 0 0;
  padding: 0 var(--space-3);
  font-size: 0.875rem;
  font-weight: var(--weight-strong);
  color: var(--color-text-secondary);
  letter-spacing: 0.02em;
}

.sidebar__list {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
}

.sidebar__chats {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar__empty {
  margin: var(--space-3);
  color: var(--color-text-secondary);
}

.link-button {
  margin: 0 var(--space-3);
  min-height: var(--target-min);
  color: var(--color-accent-text);
  text-decoration: underline;
}

.chat {
  position: relative;
  display: flex;
  align-items: center;
  border-radius: var(--radius-md);
}

.chat:hover,
.chat.is-active {
  background: var(--color-surface-hover);
}

.chat__open {
  flex: 1;
  min-width: 0;
  min-height: var(--target-min);
  padding: 0 var(--space-3);
  overflow: hidden;
  text-align: left;
  text-overflow: ellipsis;
  white-space: nowrap;
  border-radius: var(--radius-md);
}

.chat.is-active .chat__open {
  font-weight: var(--weight-title);
}

.chat__actions {
  display: none;
  align-items: center;
  padding-right: var(--space-1);
}

.chat:hover .chat__actions,
.chat:focus-within .chat__actions,
.chat.is-active .chat__actions {
  display: flex;
}

.chat--editing {
  padding: 0 var(--space-1);
}

.chat__rename {
  width: 100%;
  min-height: var(--target-min);
  padding: 0 var(--space-3);
  background: var(--color-input-bg);
  border: var(--border-hairline) solid var(--color-focus);
  border-radius: var(--radius-md);
  outline: none;
}

.chat--confirm {
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface-hover);
}

.chat__confirm-actions {
  display: flex;
  gap: var(--space-2);
}

.chat__confirm-yes,
.chat__confirm-no {
  min-height: var(--target-min);
  min-width: 4.5rem;
  padding: 0 var(--space-3);
  border-radius: var(--radius-pill);
  border: var(--border-hairline) solid var(--color-border-strong);
}

.chat__confirm-yes {
  background: var(--color-danger);
  border-color: var(--color-danger);
  color: var(--color-bg);
  font-weight: var(--weight-strong);
}

.sidebar__foot {
  position: relative;
  padding-top: var(--space-2);
  border-top: var(--border-hairline) solid var(--color-border);
}

.account__trigger {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  min-height: 3rem;
  padding: 0 var(--space-2);
  border-radius: var(--radius-md);
  text-align: left;
}

.account__trigger:hover {
  background: var(--color-surface-hover);
}

.account__name {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.account__panel {
  position: absolute;
  left: 0;
  right: 0;
  bottom: calc(100% + var(--space-2));
  z-index: 20;
  padding: var(--space-2);
  background: var(--color-bg);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-radius: var(--radius-dialog);
  box-shadow: var(--search-shadow);
}

.account__heading {
  margin: 0;
  padding: var(--space-1) var(--space-3);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.account__item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  min-height: var(--target-min);
  padding: 0 var(--space-3);
  border-radius: var(--radius-md);
  text-align: left;
}

.account__item:hover {
  background: var(--color-surface-hover);
}

.account__item[aria-checked="true"] {
  font-weight: var(--weight-title);
}

.account__rule {
  margin: var(--space-1) 0;
  border: 0;
  border-top: var(--border-hairline) solid var(--color-border);
}

.avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  flex: none;
  border-radius: 50%;
  background: var(--color-avatar-a);
  color: var(--color-avatar-text);
  font-size: 0.875rem;
  font-weight: var(--weight-strong);
}

.avatar--tone1 { background: var(--color-avatar-b); }
.avatar--tone2 { background: var(--color-avatar-c); }
.avatar--tone3 { background: var(--color-avatar-d); }
.avatar--tone4 { background: var(--color-avatar-e); }
.avatar--tone5 { background: var(--color-avatar-f); }
.avatar--tone6 { background: var(--color-avatar-g); }
.avatar--tone7 { background: var(--color-avatar-h); }

.main {
  position: relative;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  height: 100dvh;
}

.topbar {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: none;
  min-height: 3.5rem;
  padding: 0 var(--space-3);
}

.topbar__toggle {
  display: none;
}

.app.is-collapsed .topbar__toggle {
  display: inline-flex;
}

.app:not(.is-collapsed) .topbar__title {
  visibility: hidden;
}

.topbar__title {
  flex: 1;
  min-width: 0;
  margin: 0;
  overflow: hidden;
  font-size: 1rem;
  font-weight: var(--weight-title);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.launcher {
  position: relative;
  flex: none;
}

.launcher__trigger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: var(--target-min);
  min-height: var(--target-min);
  padding: 0;
  color: var(--color-text-secondary);
  background: transparent;
  border: 0;
  border-radius: var(--radius-pill);
  cursor: pointer;
}

.launcher__trigger:hover {
  background: var(--color-surface-hover);
  color: var(--color-text);
}

.launcher__icon {
  width: 1.5rem;
  height: 1.5rem;
  stroke-width: 4.5;
}

.launcher__menu {
  position: absolute;
  top: 100%;
  margin-top: var(--space-2);
  inset-inline-end: 0;
  z-index: 3;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-1);
  width: min(19rem, calc(100vw - 2rem));
  padding: var(--space-3);
  background: var(--color-bg);
  border: var(--border-hairline) solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--search-shadow);
}

.launcher__menu[hidden] {
  display: none;
}

.launcher__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  min-width: var(--target-min);
  min-height: var(--target-min);
  padding: var(--space-3) var(--space-1);
  border-radius: var(--radius-md);
  color: var(--color-text);
  text-decoration: none;
}

.launcher__tile {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  background: transparent;
  color: var(--color-text);
}

.launcher__glyph {
  width: 1.5rem;
  height: 1.5rem;
}

.launcher__name {
  font-size: var(--text-metadata);
  text-align: center;
}

.launcher__item:hover {
  color: var(--color-text);
  background: var(--color-surface-hover);
}

.topbar .launcher {
  margin-left: auto;
}

.thread {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  scroll-behavior: smooth;
}

.thread__column {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
  width: 100%;
  max-width: var(--column-width);
  margin: 0 auto;
  padding: var(--space-4) var(--space-4) var(--space-5);
}

.dock {
  flex: none;
  width: 100%;
  max-width: calc(var(--column-width) + 2 * var(--space-4));
  margin: 0 auto;
  padding: 0 var(--space-4) calc(var(--space-3) + env(safe-area-inset-bottom));
}

.dock__hint {
  margin: var(--space-2) 0 0;
  text-align: center;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.welcome {
  display: none;
  margin: 0 0 var(--space-5);
  text-align: center;
  font-family: var(--font-sans);
  font-size: clamp(2rem, 5vw, 2.75rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.main.is-empty {
  justify-content: center;
}

.main.is-empty .thread {
  display: none;
}

.main.is-empty .welcome {
  display: block;
}

.main.is-empty .topbar {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
}

.main.is-empty .dock {
  padding-bottom: 0;
}

.jump {
  position: relative;
  z-index: 5;
  display: inline-flex;
  align-items: center;
  align-self: center;
  gap: var(--space-2);
  min-height: var(--target-min);
  margin: -3.75rem 0 var(--space-2);
  padding: 0 var(--space-4);
  background: var(--color-surface);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  box-shadow: var(--search-shadow);
}

.jump:hover {
  background: var(--color-surface-hover);
}

.toast {
  position: absolute;
  left: 50%;
  bottom: 8rem;
  z-index: 30;
  max-width: calc(100% - 2 * var(--space-4));
  margin: 0;
  padding: var(--space-3) var(--space-4);
  transform: translateX(-50%);
  background: var(--color-surface-hover);
  border: var(--border-hairline) solid var(--color-danger);
  border-radius: var(--radius-md);
}

.composer {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) var(--space-3) var(--space-2) var(--space-4);
  background: var(--color-input-bg);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-radius: var(--radius-card);
  box-shadow: var(--search-shadow);
  transition: border-color var(--transition-ui);
}

.composer:focus-within {
  border-color: var(--color-focus);
}

.main.is-empty .composer {
  min-height: 8.5rem;
}

.composer__field {
  display: block;
  width: 100%;
  min-height: 2.75rem;
  max-height: 15rem;
  padding: var(--space-2) 0;
  background: none;
  border: 0;
  outline: none;
  resize: none;
  line-height: 1.5;
}

.composer__field::placeholder {
  color: var(--color-text-secondary);
}

.composer__row {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-2);
  margin-top: auto;
}

.composer__count {
  order: -1;
  margin-right: auto;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.composer__count.is-over {
  color: var(--color-danger);
  font-weight: var(--weight-strong);
}

.composer__send {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--target-min);
  height: var(--target-min);
  flex: none;
  border-radius: 50%;
  background: var(--color-text);
  color: var(--color-bg);
  transition: background var(--transition-ui);
}

.composer__send:hover:not(:disabled) {
  background: var(--color-text-secondary);
}

.composer__send:disabled {
  background: var(--color-surface-hover);
  color: var(--color-disabled);
}

.composer__send.is-stop {
  background: var(--color-text);
  color: var(--color-bg);
}

.composer__send.is-stop .icon {
  fill: currentColor;
}

.tier {
  position: relative;
}

.tier__trigger {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: var(--target-min);
  padding: 0 var(--space-3);
  border-radius: var(--radius-pill);
  color: var(--color-text-secondary);
  transition: background var(--transition-ui);
}

.tier__trigger:hover,
.tier__trigger[aria-expanded="true"] {
  background: var(--color-surface-hover);
  color: var(--color-text);
}

.tier__name {
  font-weight: var(--weight-title);
  color: var(--color-text);
  white-space: nowrap;
}

.tier__desc {
  font-size: 0.875rem;
  white-space: nowrap;
}

.tier__panel {
  position: absolute;
  right: 0;
  bottom: calc(100% + var(--space-2));
  z-index: 20;
  width: 24rem;
  max-width: calc(100vw - 2 * var(--space-4));
  padding: var(--space-2);
  background: var(--color-bg);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-radius: var(--radius-dialog);
  box-shadow: var(--search-shadow);
}

.tier__option {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 1rem;
  column-gap: var(--space-3);
  align-items: center;
  width: 100%;
  min-height: 3.25rem;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  text-align: left;
}

.tier__option:hover {
  background: var(--color-surface-hover);
}

.tier__option-name {
  grid-column: 1;
  font-weight: var(--weight-title);
}

.tier__option-desc {
  grid-column: 1;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.tier__option .icon,
.tier__option-gap {
  grid-column: 2;
  grid-row: 1 / span 2;
  color: var(--color-accent-text);
}

.msg {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.msg--user {
  align-items: flex-end;
}

.msg__bubble {
  max-width: 85%;
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface-hover);
  border-radius: var(--radius-bubble);
  white-space: pre-wrap;
}

.msg__body {
  line-height: 1.7;
}

.msg__meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-height: var(--icon-hit);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.msg__flag {
  padding: 0 var(--space-2);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-radius: var(--radius-pill);
}

.msg__action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--icon-hit);
  height: var(--icon-hit);
  border-radius: var(--radius-pill);
  color: var(--color-text-secondary);
}

.msg__action:hover {
  background: var(--color-surface-hover);
  color: var(--color-text);
}

.md > :first-child {
  margin-top: 0;
}

.md > :last-child {
  margin-bottom: 0;
}

.md-paragraph {
  margin: 0 0 var(--space-3);
}

.md-heading {
  margin: var(--space-4) 0 var(--space-2);
  font-size: 1.125rem;
  line-height: 1.35;
}

.md-list {
  margin: 0 0 var(--space-3);
  padding-left: var(--space-5);
}

.md-code {
  padding: 0.125em 0.4em;
  background: var(--color-surface-hover);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.9em;
}

.md-code-block {
  margin: 0 0 var(--space-3);
  background: var(--color-surface);
  border: var(--border-hairline) solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.md-code-block__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: var(--icon-hit);
  padding: 0 var(--space-2) 0 var(--space-4);
  border-bottom: var(--border-hairline) solid var(--color-border);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.md-code-block__copy {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: var(--icon-hit);
  padding: 0 var(--space-3);
  border-radius: var(--radius-pill);
  color: var(--color-text-secondary);
}

.md-code-block__copy:hover {
  background: var(--color-surface-hover);
  color: var(--color-text);
}

.md-code-block__pre {
  margin: 0;
  padding: var(--space-3) var(--space-4);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
}

.typing {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  min-height: var(--icon-hit);
}

.typing__dot {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: var(--color-text-secondary);
  opacity: 0.45;
  animation: typing-pulse 1.2s var(--easing-standard) infinite;
}

.typing__dot:nth-child(2) {
  animation-delay: 0.15s;
}

.typing__dot:nth-child(3) {
  animation-delay: 0.3s;
}

@keyframes typing-pulse {
  0%,
  80%,
  100% {
    opacity: 0.45;
  }
  40% {
    opacity: 1;
  }
}

.notice {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border: var(--border-hairline) solid var(--color-border-strong);
  border-left: 4px solid var(--color-danger);
  border-radius: var(--radius-md);
}

.notice__text {
  flex: 1 1 14rem;
}

.notice__retry,
.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: var(--target-min);
  padding: 0 var(--space-4);
  background: var(--color-accent);
  border-radius: var(--radius-pill);
  color: var(--color-accent-contrast);
  font-weight: var(--weight-title);
}

.notice__retry:hover:not(:disabled),
.primary-button:hover {
  background: var(--color-accent-hover);
}

.notice__retry:disabled {
  background: var(--color-surface-hover);
  color: var(--color-disabled);
}

.screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  min-height: 100dvh;
  padding: var(--space-5) var(--space-4);
  text-align: center;
}

.screen__title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--text-heading);
  font-weight: var(--weight-regular);
}

.screen__text {
  max-width: 28rem;
  margin: 0;
  color: var(--color-text-secondary);
}

.noscript {
  padding: var(--space-5) var(--space-4);
  text-align: center;
}

@media (hover: none) {
  .chat__actions {
    display: flex;
  }
}

@media (pointer: coarse) {
  :root {
    --icon-hit: 2.75rem;
  }
}

@media (max-width: 767px) {
  .app,
  .app.is-collapsed {
    grid-template-columns: minmax(0, 1fr);
  }

  .sidebar,
  .app.is-collapsed .sidebar {
    display: flex;
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 40;
    width: min(20rem, 86vw);
    padding-top: calc(var(--space-3) + env(safe-area-inset-top));
    transform: translateX(-100%);
    visibility: hidden;
    transition: transform var(--duration-fast) var(--easing-standard), visibility 0s linear var(--duration-fast);
  }

  .app.is-drawer .sidebar {
    transform: none;
    visibility: visible;
    transition: transform var(--duration-fast) var(--easing-standard);
  }

  .app.is-drawer .scrim {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 35;
    background: var(--color-overlay);
  }

  .topbar__toggle,
  .app.is-collapsed .topbar__toggle {
    display: inline-flex;
  }

  :root {
    --icon-hit: 2.75rem;
  }

  .tier__desc,
  .dock__hint {
    display: none;
  }

  .msg__bubble {
    max-width: 92%;
  }

  .main.is-empty .composer {
    min-height: 7.5rem;
  }

  .toast {
    bottom: 6.5rem;
  }
}