:root {
  color-scheme: light dark;

  --background: #f7f7f8;
  --panel: #ffffff;
  --panel-secondary: #f1f1f3;
  --text: #202123;
  --muted: #6b6c70;
  --border: #d9d9df;
  --button: #202123;
  --button-text: #ffffff;
  --user-message: #dbeafe;
  --assistant-message: #ffffff;
  --danger: #b91c1c;
  --danger-background: #fef2f2;
  --overlay: rgba(0, 0, 0, 0.45);
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #212121;
    --panel: #2f2f2f;
    --panel-secondary: #171717;
    --text: #ececec;
    --muted: #a7a7a7;
    --border: #464646;
    --button: #ececec;
    --button-text: #171717;
    --user-message: #2b4162;
    --assistant-message: #2f2f2f;
    --danger: #fca5a5;
    --danger-background: #450a0a;
    --overlay: rgba(0, 0, 0, 0.7);
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
}

body {
  background: var(--background);
  color: var(--text);
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
}

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

button {
  border: 0;
  border-radius: 10px;
  background: var(--button);
  color: var(--button-text);
  padding: 11px 15px;
  font-weight: 700;
  cursor: pointer;
}

button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

input,
textarea,
select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--panel);
  color: var(--text);
  padding: 11px 12px;
  outline: none;
}

input:focus,
textarea:focus,
select:focus {
  border-color: #60a5fa;
  box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.18);
}

label {
  display: block;
  margin: 15px 0 6px;
  font-weight: 700;
}

.hidden {
  display: none !important;
}

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

.error-message {
  min-height: 20px;
  color: var(--danger);
}

.login-screen {
  min-height: 100%;
  display: grid;
  place-items: center;
  padding: 20px;
}

.login-card {
  width: min(100%, 420px);
  padding: 25px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: 0 20px 55px rgba(0, 0, 0, 0.15);
}

.login-card h1 {
  margin: 0 0 8px;
}

.login-card button {
  width: 100%;
  margin-top: 18px;
}

.app {
  width: 100%;
  height: 100%;
  max-width: 1350px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  background: var(--panel);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
}

.sidebar {
  min-width: 0;
  display: grid;
  grid-template-rows: auto 1fr auto;
  background: var(--panel-secondary);
  border-right: 1px solid var(--border);
}

.sidebar-header {
  padding: 12px;
  border-bottom: 1px solid var(--border);
}

.new-chat-button {
  width: 100%;
}

.chat-list {
  overflow-y: auto;
  padding: 8px;
}

.chat-list-item {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
  padding: 10px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  text-align: left;
}

.chat-list-item:hover {
  background: var(--panel);
}

.chat-list-item.active {
  background: var(--panel);
  border-color: var(--border);
}

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

.chat-menu-button {
  padding: 4px 7px;
  background: transparent;
  color: var(--muted);
}

.sidebar-footer {
  padding: 12px;
  border-top: 1px solid var(--border);
}

.sidebar-footer button {
  width: 100%;
  margin-top: 8px;
}

.secondary-button {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.chat-area {
  min-width: 0;
  height: 100%;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.chat-header {
  min-height: 62px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.menu-button {
  display: none;
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

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

.chat-heading strong {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.chat-heading span {
  margin-top: 2px;
  font-size: 13px;
  color: var(--muted);
}

.messages {
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 20px;
  scroll-behavior: smooth;
}

.empty-state {
  max-width: 440px;
  margin: auto;
  padding: 30px;
  text-align: center;
  color: var(--muted);
}

.message {
  max-width: min(82%, 760px);
  align-self: flex-start;
  padding: 11px 13px;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--assistant-message);
  line-height: 1.48;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.message.user-message {
  align-self: flex-end;
  background: var(--user-message);
}

.message-meta {
  display: flex;
  gap: 8px;
  align-items: baseline;
  margin-bottom: 5px;
  color: var(--muted);
  font-size: 12px;
}

.message-meta strong {
  color: var(--text);
}

.message-form {
  padding: 10px;
  padding-bottom: max(10px, env(safe-area-inset-bottom));
  background: var(--panel);
  border-top: 1px solid var(--border);
}

.name-row,
.message-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
}

.name-row {
  margin-bottom: 8px;
}

.message-row {
  align-items: end;
}

textarea {
  min-height: 50px;
  max-height: 180px;
  resize: none;
}

.typing-status {
  min-height: 20px;
  padding: 6px 3px 0;
  color: var(--muted);
  font-size: 13px;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: 15px;
  background: var(--overlay);
}

.modal {
  width: min(100%, 520px);
  max-height: 92vh;
  overflow-y: auto;
  padding: 20px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 22px 70px rgba(0, 0, 0, 0.35);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.modal-header h2 {
  margin: 0;
}

.close-button {
  padding: 3px 8px;
  background: transparent;
  color: var(--text);
  font-size: 25px;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 18px;
}

.danger-button {
  margin-right: auto;
  background: var(--danger);
  color: #ffffff;
}

.usage-information {
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--panel-secondary);
  color: var(--muted);
}

@media (max-width: 760px) {
  .app {
    display: block;
    border: 0;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 15;
    width: min(85vw, 310px);
    transform: translateX(-105%);
    transition: transform 0.2s ease;
    box-shadow: 8px 0 30px rgba(0, 0, 0, 0.25);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .chat-area {
    width: 100%;
  }

  .menu-button {
    display: inline-block;
  }

  .messages {
    padding: 12px;
  }

  .message {
    max-width: 92%;
  }

  .name-row {
    grid-template-columns: minmax(0, 1fr) auto;
  }
}