:root {
  color-scheme: light;
  --background: #fbfbfd;
  --surface: rgba(255, 255, 255, 0.86);
  --text: #1d1d1f;
  --muted: #86868b;
  --divider: rgba(0, 0, 0, 0.08);
  --brand: #2563eb;
  --brand-hover: #1d4ed8;
  --focus: rgba(37, 99, 235, 0.22);
  --font: "Lato", -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", sans-serif;
}

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

html {
  min-width: 320px;
  background: var(--background);
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
}

button,
input {
  font: inherit;
}

.site-header {
  position: fixed;
  z-index: 10;
  top: 0;
  right: 0;
  left: 0;
  height: 64px;
  display: flex;
  align-items: center;
  padding: 0 clamp(22px, 5vw, 52px);
  background: rgba(251, 251, 253, 0.82);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  backdrop-filter: saturate(180%) blur(18px);
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  color: var(--text);
  text-decoration: none;
}

.brand img {
  align-self: center;
  width: 30px;
  height: 30px;
  margin-right: 3px;
}

.brand-name {
  font-size: 17px;
  font-weight: 650;
  letter-spacing: -0.025em;
}

.brand-cn {
  color: var(--muted);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

.page-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 118px 22px 64px;
}

.hero {
  width: min(100%, 700px);
  text-align: center;
  transform: translateY(-3vh);
}

h1 {
  display: inline-flex;
  align-items: baseline;
  margin: 0;
  font-size: clamp(52px, 9vw, 88px);
  font-weight: 720;
  line-height: 0.95;
  letter-spacing: -0.065em;
}

h1 .ind {
  color: #60a5fa;
}

.availability {
  margin: 24px 0 0;
  color: var(--text);
  font-size: clamp(20px, 3vw, 26px);
  font-weight: 650;
  letter-spacing: -0.025em;
}

.availability-copy {
  max-width: 560px;
  margin: 12px auto 34px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
  letter-spacing: -0.01em;
}

.assistant {
  width: 100%;
  margin: 0 auto;
  padding: 24px;
  border: 1px solid var(--divider);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.7);
  box-shadow: 0 12px 34px rgba(0, 0, 0, 0.045);
  text-align: left;
}

.assistant-intro {
  margin-bottom: 18px;
}

.assistant-eyebrow {
  margin: 0 0 7px;
  color: var(--brand);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: 0.08em;
}

.assistant h2 {
  margin: 0;
  color: var(--text);
  font-size: 21px;
  font-weight: 680;
  line-height: 1.35;
  letter-spacing: -0.025em;
}

.assistant-description {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.search-capsule {
  width: 100%;
  height: 52px;
  display: flex;
  align-items: center;
  overflow: hidden;
  border: 1px solid rgba(0, 0, 0, 0.09);
  border-radius: 999px;
  background: var(--surface);
  box-shadow: 0 14px 38px rgba(0, 0, 0, 0.07), 0 2px 8px rgba(0, 0, 0, 0.035);
  transition: border-color 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.search-capsule:focus-within {
  border-color: rgba(37, 99, 235, 0.38);
  background: #fff;
  box-shadow: 0 14px 38px rgba(0, 0, 0, 0.07), 0 0 0 4px var(--focus);
}

.search-icon {
  width: 52px;
  height: 52px;
  display: inline-flex;
  flex: 0 0 52px;
  align-items: center;
  justify-content: center;
  color: #6e6e73;
}

.search-icon svg {
  width: 20px;
  height: 20px;
}

.search-capsule input {
  min-width: 0;
  height: 100%;
  flex: 1;
  padding: 0 8px 0 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
  font-size: 16px;
  letter-spacing: -0.01em;
}

.search-capsule input::placeholder {
  color: #9a9a9f;
}

.char-count {
  flex: 0 0 auto;
  margin-right: 8px;
  color: var(--muted);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.send-button {
  width: 38px;
  height: 38px;
  display: inline-grid;
  flex: 0 0 38px;
  place-items: center;
  margin-right: 6px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: var(--brand);
  color: #fff;
  cursor: pointer;
  transition: background 160ms ease, transform 160ms ease, opacity 160ms ease;
}

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

.send-button:active {
  transform: scale(0.94);
}

.send-button:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.send-button:disabled {
  cursor: default;
  opacity: 0.36;
}

.send-arrow {
  font-size: 21px;
  font-weight: 500;
  line-height: 1;
  transform: translateY(-1px);
}

.stop-square {
  display: none;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: currentColor;
}

.is-streaming .send-arrow {
  display: none;
}

.is-streaming .stop-square {
  display: block;
}

.input-status {
  min-height: 18px;
  margin: 5px 12px 0;
  color: #b42318;
  font-size: 12px;
  text-align: left;
}

.assistant-privacy {
  margin: 10px 12px 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.55;
}

.conversation {
  margin-top: 4px;
  text-align: left;
}

.exchange {
  padding: 22px 8px 20px;
  border-bottom: 1px solid var(--divider);
}

.exchange:last-child {
  border-bottom: 0;
}

.question {
  margin: 0 0 11px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 550;
  line-height: 1.55;
  white-space: pre-wrap;
}

.answer {
  margin: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.72;
  letter-spacing: -0.005em;
  overflow-wrap: anywhere;
}

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

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

.answer p {
  margin: 0 0 0.72em;
}

.answer strong {
  font-weight: 680;
}

.answer em {
  font-style: italic;
}

.answer del {
  color: var(--muted);
  text-decoration-thickness: 1px;
}

.answer .md-heading {
  margin: 1.05em 0 0.42em;
  font-size: 16px;
  font-weight: 680;
  line-height: 1.45;
  letter-spacing: -0.012em;
}

.answer .md-heading-1,
.answer .md-heading-2 {
  font-size: 17px;
}

.answer ul,
.answer ol {
  margin: 0.3em 0 0.85em;
  padding-left: 1.45em;
}

.answer li {
  padding-left: 0.16em;
}

.answer li + li {
  margin-top: 0.28em;
}

.answer code {
  padding: 0.13em 0.34em;
  border-radius: 5px;
  background: rgba(0, 0, 0, 0.055);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.88em;
}

.answer pre {
  margin: 0.45em 0 0.9em;
  padding: 13px 15px;
  overflow-x: auto;
  border: 1px solid var(--divider);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.72);
  line-height: 1.55;
  white-space: pre;
}

.answer pre code {
  padding: 0;
  background: transparent;
  font-size: 12.5px;
}

.answer blockquote {
  margin: 0.4em 0 0.85em;
  padding-left: 0.9em;
  border-left: 2px solid rgba(37, 99, 235, 0.36);
  color: #5f6065;
}

.answer hr {
  height: 1px;
  margin: 1em 0;
  border: 0;
  background: var(--divider);
}

.answer a {
  color: var(--brand);
  text-decoration: none;
}

.answer a:hover {
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

.answer.is-pending::after {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-left: 5px;
  border-radius: 50%;
  background: var(--brand);
  animation: breathe 1s ease-in-out infinite alternate;
}

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

@keyframes breathe {
  from { opacity: 0.25; transform: scale(0.8); }
  to { opacity: 1; transform: scale(1); }
}

@media (max-width: 560px) {
  .site-header {
    height: 58px;
    padding-inline: 18px;
  }

  .page-shell {
    align-items: start;
    padding: 112px 16px 48px;
  }

  .hero {
    transform: none;
  }

  .availability {
    margin-top: 20px;
  }

  .availability-copy {
    margin-bottom: 28px;
    font-size: 14px;
  }

  .assistant {
    padding: 20px 16px;
    border-radius: 20px;
  }

  .search-capsule {
    height: 50px;
  }

  .search-icon {
    width: 48px;
    height: 50px;
    flex-basis: 48px;
  }

  .exchange {
    padding-inline: 5px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}