:root {
  color-scheme: light;
  --bg: #eef3f1;
  --ink: #17211d;
  --muted: #66746e;
  --panel: #ffffff;
  --line: #d9e2dd;
  --brand: #0f766e;
  --brand-strong: #0b5f59;
  --bot: #f3f7f5;
  --user: #dff3ed;
  --danger: #9f1239;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: Arial, "Tahoma", sans-serif;
}

button,
textarea {
  font: inherit;
}

.shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.chat {
  width: min(720px, 100%);
  height: min(760px, calc(100vh - 48px));
  min-height: 520px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 18px 48px rgb(23 33 29 / 12%);
}

.chat__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--muted);
  direction: ltr;
  text-align: right;
  font-size: 13px;
}

h1 {
  margin: 0;
  font-size: 22px;
  line-height: 1.25;
}

.icon-button {
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--brand);
  cursor: pointer;
  font-size: 22px;
}

.icon-button:hover {
  border-color: var(--brand);
}

.messages {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 18px;
  overflow-y: auto;
}

.message {
  width: fit-content;
  max-width: min(82%, 560px);
  padding: 10px 12px;
  border-radius: 8px;
  line-height: 1.55;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.message--bot {
  align-self: flex-start;
  background: var(--bot);
  border: 1px solid var(--line);
}

.message--user {
  align-self: flex-end;
  background: var(--user);
  border: 1px solid #bee6dc;
}

.message--error {
  color: var(--danger);
  background: #fff1f2;
  border-color: #fecdd3;
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  padding: 14px;
  border-top: 1px solid var(--line);
  background: #fbfdfc;
}

textarea {
  width: 100%;
  min-height: 44px;
  max-height: 130px;
  resize: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  outline: none;
}

textarea:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgb(15 118 110 / 12%);
}

.composer button {
  min-width: 88px;
  height: 44px;
  border: 0;
  border-radius: 8px;
  background: var(--brand);
  color: #fff;
  cursor: pointer;
  font-weight: 700;
}

.composer button:hover {
  background: var(--brand-strong);
}

.composer button:disabled {
  cursor: wait;
  opacity: 0.65;
}

@media (max-width: 560px) {
  .shell {
    padding: 0;
  }

  .chat {
    min-height: 100vh;
    height: 100vh;
    border: 0;
    border-radius: 0;
  }

  .composer {
    grid-template-columns: 1fr;
  }

  .composer button {
    width: 100%;
  }
}