:root {
  --base-font-size: calc(1rem + 0.1618vw);
  --ratio: 1.618;
  --s-2: calc(var(--s-1) / var(--ratio));
  --s-1: calc(var(--s0) / var(--ratio));
  --s0: var(--base-font-size);
  --s1: calc(var(--s0) * var(--ratio));
  --s2: calc(var(--s1) * var(--ratio));
  --s3: calc(var(--s2) * var(--ratio));

  --font-sans: system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, monospace;

  --color-black: #1d1f21;
  --color-blue: #4271ae;
  --color-brown: #a3685a;
  --color-cyan: #3e999f;
  --color-gray0: #efefef;
  --color-gray1: #e0e0e0;
  --color-gray2: #d6d6d6;
  --color-gray3: #8e908c;
  --color-gray4: #969896;
  --color-gray5: #4d4d4c;
  --color-gray6: #282a2e;
  --color-green: #718c00;
  --color-orange: #f5871f;
  --color-purple: #8959a8;
  --color-red: #c82829;
  --color-yellow: #eab700;

  --color-bg: var(--color-gray0);
  --color-surface: white;
  --color-text: var(--color-black);
  --color-text-muted: var(--color-gray3);
  --color-border: var(--color-black);
  --color-border-light: var(--color-gray2);
  --color-primary: var(--color-blue);
  --color-primary-hover: var(--color-cyan);
  --color-recording: var(--color-red);
  --color-error: var(--color-yellow);

  --measure: 80ch;
  --radius: 0.375rem;
  --icon-size: 1.25rem;
  --action-icon-size: 0.875rem;
  --border-width: 2px;
  --textarea-line-height: 1.5rem;
}

/* ==================== */
/* Reset                */
/* ==================== */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
}

/* ==================== */
/* Base                 */
/* ==================== */

html {
  font-size: 100%;
  font-family: var(--font-sans);
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-bg);
}

body {
  overflow: hidden;
  min-height: 100dvh;
}

/* ==================== */
/* Layout               */
/* ==================== */

.container {
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
  height: 100dvh;
  max-width: calc(var(--measure) + var(--s3) * 2);
  margin-inline: auto;
  padding: var(--s0);
  padding-bottom: 0;
}

/* ==================== */
/* Chat                 */
/* ==================== */

.chat {
  flex: 1 1 0;
  min-height: 0;
  overflow-y: auto;
  padding: var(--s1);
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
}

.chat > * + * {
  margin-top: var(--s0);
}

/* ==================== */
/* Collapsible          */
/* ==================== */

.collapsible {
  border: 1px dashed var(--color-border-light);
  border-radius: var(--radius);
}

.collapsible[open] .collapsible__summary::before {
  transform: rotate(90deg);
}

.collapsible:last-of-type:has(~ .message__actions:empty) {
  border-bottom: none;
}

.collapsible__content {
  padding: var(--s-2) var(--s-1);
  border-top: 1px dashed var(--color-border-light);
}

.collapsible__content > pre {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--s-1);
  white-space: pre-wrap;
  word-break: break-word;
}

.collapsible__label {
  font-size: var(--s-1);
  color: var(--color-text-muted);
}

.collapsible__pre {
  margin: 0;
  padding: var(--s-2);
  font-family: var(--font-mono);
  font-size: var(--s-1);
  background: var(--color-bg);
  border-radius: var(--radius);
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

.collapsible__section {
  margin-bottom: var(--s-2);
}

.collapsible__section:last-child {
  margin-bottom: 0;
}

.collapsible__section-label {
  font-size: var(--s-2);
  font-weight: 500;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.collapsible__summary {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  padding: var(--s-2) var(--s-1);
  cursor: pointer;
  user-select: none;
  list-style: none;
}

.collapsible__summary::-webkit-details-marker {
  display: none;
}

.collapsible__summary::before {
  content: "▶";
  font-size: 0.625em;
  color: var(--color-text-muted);
  transition: transform 0.15s ease;
}

.collapsible__summary .icon {
  width: var(--icon-size);
  height: var(--icon-size);
  color: var(--color-text-muted);
}

.collapsible--reasoning .collapsible__summary .icon {
  color: var(--color-purple);
}

.collapsible--reasoning:has(+ .collapsible--tool) {
  margin-bottom: 0;
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.collapsible--reasoning + .collapsible--tool {
  margin-top: 0;
  border-top: none;
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

.collapsible--tool .collapsible__summary .icon {
  color: var(--color-orange);
}

/* ==================== */
/* Compose              */
/* ==================== */

.compose {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: var(--s0);
}

.compose__action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.25rem;
  background: transparent;
  border: none;
  border-radius: 0.25rem;
  color: var(--color-text-muted);
  cursor: pointer;
  transition:
    color 0.15s ease,
    background-color 0.15s ease;
}

@media (hover: hover) {
  .compose__action-btn:hover {
    color: var(--color-text);
  }
}

.compose__action-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 1px;
}

.compose__action-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.compose__action-btn .icon {
  width: var(--action-icon-size);
  height: var(--action-icon-size);
}

.compose__action-btn--record.recording {
  color: white;
  background: var(--color-recording);
  animation: pulse 1s ease-in-out infinite;
}

.compose__action-btn--send.loading {
  position: relative;
  color: transparent;
  pointer-events: none;
}

.compose__action-btn--send.loading::after {
  content: "";
  position: absolute;
  width: 0.75rem;
  height: 0.75rem;
  border: 2px solid var(--color-gray2);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.compose__actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.125rem var(--s-2);
  border-top: 1px dotted var(--color-border-light);
}

.compose__actions-right {
  display: flex;
  align-items: center;
  gap: 0.125rem;
}

.compose__attachment {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.125rem 0.375rem;
  font-size: var(--s-1);
  background: var(--color-gray1);
  border-radius: var(--radius);
  color: var(--color-text);
}

.compose__attachment-name {
  max-width: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.compose__attachment-remove {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  background: none;
  border: none;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: color 0.15s ease;
}

@media (hover: hover) {
  .compose__attachment-remove:hover {
    color: var(--color-red);
  }
}

.compose__attachment-remove .icon {
  width: 0.875rem;
  height: 0.875rem;
}

.compose__attachments {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2);
  padding: var(--s-2) var(--s-1);
  border-top: 1px dotted var(--color-border-light);
}

.compose__attachments:empty {
  display: none;
}

.compose__textarea {
  display: block;
  width: 100%;
  height: auto;
  min-height: calc(var(--textarea-line-height) + var(--s-1) * 2);
  max-height: calc(var(--textarea-line-height) * 5 + var(--s-1) * 2);
  padding: var(--s-1);
  font-family: inherit;
  font-size: var(--s0);
  line-height: var(--textarea-line-height);
  color: var(--color-text);
  background: var(--color-surface);
  border: none;
  resize: none;
  overflow-y: auto;
  field-sizing: content;
}

.compose__textarea:focus {
  outline: none;
}

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

/* ==================== */
/* Footer               */
/* ==================== */

.footer {
  margin-top: var(--s0);
  background: var(--color-bg);
}

.footer__select {
  height: 2rem;
  padding: 0 var(--s-1);
  font-family: inherit;
  font-size: var(--s-1);
  line-height: 2rem;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  cursor: pointer;
  max-width: 150px;
}

.footer__select:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.footer__toolbar {
  border-inline: none;
  border-bottom: none;
  display: flex;
  align-items: center;
  gap: var(--s-2);
  padding: var(--s-2);
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
}

.footer__toolbar-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 2rem;
  width: 2rem;
  padding: 0;
  background: transparent;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all 0.15s ease;
}

@media (hover: hover) {
  .footer__toolbar-btn:hover {
    color: var(--color-text);
    border-color: var(--color-text-muted);
  }
}

.footer__toolbar-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.footer__toolbar-btn .icon {
  width: 1rem;
  height: 1rem;
}

.footer__toolbar-btn--muted {
  color: var(--color-red);
  border-color: var(--color-red);
}

@media (hover: hover) {
  .footer__toolbar-btn--muted:hover {
    color: var(--color-red);
    border-color: var(--color-red);
  }
}

.footer__toolbar-spacer {
  flex: 1;
}

/* ==================== */
/* Message              */
/* ==================== */

.message {
  display: flex;
  max-width: 100%;
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.message--assistant .message__icon {
  color: var(--color-primary);
}

.message--debug-open .message__debug {
  display: block;
}

.message--error {
  border-color: var(--color-error);
}

.message--error .message__icon {
  border-color: var(--color-error);
}

.message--user .message__icon {
  color: var(--color-green);
}

.message__action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.125rem;
  background: transparent;
  border: none;
  border-radius: 0.125rem;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: color 0.15s ease;
}

@media (hover: hover) {
  .message__action-btn:hover {
    color: var(--color-text);
  }
}

.message__action-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 1px;
}

.message__action-btn svg {
  width: var(--action-icon-size);
  height: var(--action-icon-size);
}

.message__action-btn--success {
  color: var(--color-primary);
}

.message__actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.125rem;
  padding: 0.125rem 0.25rem;
  border-top: 1px dotted var(--color-border-light);
  background: var(--color-surface);
}

.message__actions:empty {
  display: none;
}

.message__body {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.message__content {
  padding: var(--s-2) var(--s-1);
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.message__content img {
  display: block;
  max-width: 100%;
  height: auto;
  margin-block: var(--s-1);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
}

.message__debug {
  display: none;
  padding: var(--s-2) var(--s-1);
  border-top: 1px dotted var(--color-border-light);
  background: var(--color-surface);
}

.message__debug-list {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.125rem 1rem;
  margin: 0;
  font-size: var(--s-1);
}

.message__debug-list dt,
.message__debug-list dd {
  margin: 0;
  text-align: left;
  color: var(--color-text);
}

.message__debug-list dt {
  white-space: nowrap;
}

.message__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--s-2);
  border-right: var(--border-width) solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text-muted);
}

.message__icon svg {
  width: var(--icon-size);
  height: var(--icon-size);
}

/* ==================== */
/* Animations           */
/* ==================== */

@keyframes pulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

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

/* ==================== */
/* Media: Mobile        */
/* ==================== */

@media (max-width: 639px) {
  .container {
    padding: 0;
    padding-top: var(--s-1);
  }

  .chat {
    border-radius: 0;
    border-inline: none;
  }

  .footer {
    margin-top: var(--s-1);
    padding-bottom: 0;
  }

  .compose {
    border-radius: 0;
    border-inline: none;
    margin-bottom: var(--s-1);
  }

  .compose__action-btn {
    min-width: 44px;
    min-height: 44px;
    padding: var(--s-1);
  }

  .compose__action-btn .icon {
    width: var(--icon-size);
    height: var(--icon-size);
  }

  .footer__toolbar {
    border-inline: none;
    border-bottom: none;
    border-radius: 0;
    margin-top: 0;
  }

  .footer__toolbar-btn {
    height: 1.75rem;
    width: 1.75rem;
  }

  .footer__select {
    height: 1.75rem;
    line-height: 1.75rem;
    max-width: 128px;
    font-size: var(--s-1);
  }
}