* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #f7f7f7;
  color: #111111;
  min-height: 100vh;
}

.page {
  width: min(980px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0;
}

.hero {
  margin-bottom: 28px;
}

.lab-logo {
  width: min(180px, 42vw);
  height: auto;
  display: block;
  margin: 0 0 26px;
}

h1 {
  font-size: clamp(38px, 7vw, 82px);
  line-height: 0.92;
  margin: 0 0 18px;
  letter-spacing: -0.05em;
  color: #111111;
}

.intro {
  max-width: 760px;
  font-size: 20px;
  line-height: 1.45;
  margin: 0 0 14px;
  color: #111111;
}

.notice,
.limit-note {
  max-width: 760px;
  font-size: 14px;
  line-height: 1.45;
  color: #111111;
  margin: 0 0 8px;
}

.chat-shell {
  background: #eeeeee;
  border: 1px solid rgba(0, 0, 0, 0.12);
  border-radius: 24px;
  padding: 22px;
  box-shadow: none;
}

.messages {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-height: 300px;
  max-height: 58vh;
  overflow-y: auto;
  padding: 4px 4px 18px;
}

.message {
  padding: 16px 18px;
  border-radius: 18px;
  line-height: 1.55;
  white-space: pre-wrap;
}

.message p {
  margin: 0;
}

.message.user {
  margin: 0;
  text-align: left;
  max-width: 78%;
  background: #111111;
  color: #ffffff;
}

.message.assistant {
  align-self: flex-start;
  max-width: 86%;
  background: #ffffff;
  color: #111111;
  border: 1px solid rgba(0, 0, 0, 0.09);
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  margin-top: 16px;
}

textarea {
  width: 100%;
  resize: vertical;
  min-height: 88px;
  border-radius: 18px;
  padding: 14px;
  font-size: 16px;
  border: 1px solid #cccccc;
  background: #ffffff;
  color: #111111;
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
}

textarea:focus {
  outline: none;
  border-color: #b7a06a;
  box-shadow: 0 0 0 3px rgba(183, 160, 106, 0.18);
}

button {
  align-self: end;
  border: 0;
  border-radius: 999px;
  padding: 14px 22px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  background: #111111;
  color: #ffffff;
  font-family: Arial, Helvetica, sans-serif;
}

button:hover {
  background: #b7a06a;
  color: #111111;
}

button:disabled {
  opacity: 0.55;
  cursor: wait;
}

a {
  color: #111111;
  font-weight: 700;
}

@media (max-width: 680px) {
  .composer {
    grid-template-columns: 1fr;
  }

  button {
    width: 100%;
  }

  .message.user,
  .message.assistant {
    max-width: 100%;
  }

  .lab-logo {
    margin-left: auto;
    margin-right: auto;
  }

  .hero {
    text-align: center;
  }

  .intro,
  .notice,
  .limit-note {
    margin-left: auto;
    margin-right: auto;
  }
}