:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-2: #f1f4fa;
  --border: #d6dde8;
  --brand: #003399;
  --brand-strong: #0044aa;
  --brand-soft: #e6edff;
  --accent: #0e7acf;
  --text: #1b2430;
  --muted: #5b6b84;
  --display: "IBM Plex Sans", sans-serif;
  --mono: "IBM Plex Mono", monospace;
  --shadow: 0 18px 36px rgba(18, 33, 66, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--display);
  color: var(--text);
  background: radial-gradient(circle at 15% 20%, rgba(0, 51, 153, 0.12), transparent 45%),
    radial-gradient(circle at 85% 0%, rgba(14, 122, 207, 0.12), transparent 50%), var(--bg);
}

.topbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.topbar-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.2rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.brand-mark {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
  color: #fff;
  font-weight: 700;
  display: grid;
  place-items: center;
  font-family: var(--mono);
  letter-spacing: 0.04em;
}

.brand-title {
  font-weight: 700;
  font-size: 1.1rem;
}

.brand-sub {
  font-size: 0.85rem;
  color: var(--muted);
}

.topbar-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.meta {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}

.hero {
  padding: 2.5rem 1.5rem 1.5rem;
}

.hero-inner {
  max-width: 900px;
  margin: 0 auto;
}

.hero h1 {
  font-size: clamp(1.9rem, 3vw, 2.8rem);
  margin: 0 0 0.8rem;
}

.hero p {
  color: var(--muted);
  max-width: 600px;
}

.pill {
  display: inline-flex;
  padding: 0.3rem 0.8rem;
  border-radius: 999px;
  background: var(--brand-soft);
  border: 1px solid rgba(0, 51, 153, 0.2);
  color: var(--brand);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.grid {
  max-width: 1100px;
  margin: 2rem auto 4rem;
  padding: 0 1.5rem;
  display: grid;
  gap: 1.5rem;
  grid-template-columns: minmax(0, 1fr);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1.6rem;
  box-shadow: var(--shadow);
}

.card.chat {
  display: flex;
  flex-direction: column;
  min-height: 640px;
}

.card.full {
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.status {
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-size: 0.75rem;
  border: 1px solid var(--border);
  color: var(--muted);
  background: var(--surface-2);
}

.status-row {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 0.75rem;
  justify-content: space-between;
  flex-wrap: wrap;
}

.chat-log {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem;
  flex: 1;
  min-height: 280px;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.chat-msg {
  padding: 0.75rem 0.9rem;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.06);
}

.chat-msg.user {
  border-color: rgba(0, 51, 153, 0.2);
  background: var(--brand-soft);
  align-self: flex-end;
}

.chat-msg.assistant {
  border-color: rgba(14, 122, 207, 0.25);
}

.chat-msg p {
  margin: 0.4rem 0 0;
  color: #1f2a3a;
  font-size: 0.95rem;
  line-height: 1.5;
}

.chat-msg strong {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.chat-msg a {
  color: var(--brand);
  text-decoration: underline;
}

.inline-code {
  font-family: var(--mono);
  font-size: 0.85rem;
  background: rgba(0, 51, 153, 0.08);
  border: 1px solid rgba(0, 51, 153, 0.2);
  padding: 0.1rem 0.3rem;
  border-radius: 6px;
}

.code-block {
  margin: 0.75rem 0 0;
  padding: 0.9rem 1rem;
  background: #0f172a;
  color: #e2e8f0;
  border-radius: 12px;
  border: 1px solid rgba(15, 23, 42, 0.5);
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.88rem;
  line-height: 1.5;
  position: relative;
}

.code-block::before {
  content: attr(data-lang);
  position: absolute;
  top: 0.5rem;
  right: 0.75rem;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(226, 232, 240, 0.6);
}

.code-block code {
  white-space: pre;
  display: block;
}

textarea {
  width: 100%;
  margin-top: 0.8rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 0.9rem;
  background: var(--surface);
  color: var(--text);
  font-family: var(--display);
  font-size: 0.95rem;
  box-shadow: inset 0 1px 3px rgba(17, 24, 39, 0.06);
}

textarea:focus {
  outline: none;
  border-color: rgba(0, 51, 153, 0.4);
  box-shadow: 0 0 0 3px rgba(0, 51, 153, 0.12);
}

.actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 0.9rem;
  flex-wrap: wrap;
}

button {
  padding: 0.6rem 1.2rem;
  border-radius: 10px;
  border: none;
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--display);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

button:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 16px rgba(0, 51, 153, 0.18);
}

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

.suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0 0.4rem;
}

.suggestion-chip {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.4rem 0.7rem;
  border-radius: 999px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease;
  box-shadow: none;
  font-weight: 500;
}

.suggestion-chip:hover {
  border-color: rgba(0, 51, 153, 0.3);
  color: var(--brand);
  background: var(--brand-soft);
  transform: none;
  box-shadow: none;
}

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

footer {
  text-align: center;
  padding: 2rem 1rem 3rem;
  color: var(--muted);
}

.about {
  padding: 0 1.5rem 3rem;
}

.about-inner {
  max-width: 900px;
  margin: 0 auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1.5rem 1.8rem;
  box-shadow: var(--shadow);
}

.about-inner h3 {
  margin: 0 0 0.6rem;
  font-size: 1.1rem;
}

.about-inner p {
  color: var(--muted);
  margin: 0 0 1rem;
  line-height: 1.6;
}

.link-row {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.link-row a {
  color: var(--brand);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  border: 1px solid rgba(0, 51, 153, 0.2);
  background: var(--brand-soft);
}