:root {
  --paper: #f5f5f1;
  --paper-raised: #ffffff;
  --ink: #1c201f;
  --ink-soft: #55605c;
  --ink-faint: #838d87;
  --accent: #146b5e;
  --accent-soft: #dceae6;
  --gold: #93621f;
  --line: #d9d7cd;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "IBM Plex Sans", "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "IBM Plex Mono", "SF Mono", Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #14171a;
    --paper-raised: #1b1f22;
    --ink: #ecede8;
    --ink-soft: #a7aea9;
    --ink-faint: #7c857f;
    --accent: #5cc4ac;
    --accent-soft: #1e2c29;
    --gold: #dcab5c;
    --line: #2b302d;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

.page {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px 56px;
  display: flex;
  flex-direction: column;
}

.banner {
  border-bottom: 1px solid var(--line);
  padding-block: 14px;
  margin-bottom: 40px;
}

.banner p {
  margin: 0;
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--ink-soft);
}

.banner a {
  color: var(--accent);
}

.eyebrow {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 14px;
}

h1 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.9rem, 5vw, 2.4rem);
  margin: 0 0 10px;
  text-wrap: balance;
}

.sub {
  font-family: var(--serif);
  font-size: 1.1rem;
  line-height: 1.5;
  color: var(--ink-soft);
  max-width: 52ch;
  margin: 0 0 32px;
  text-wrap: balance;
}

.chat-log {
  display: flex;
  flex-direction: column;
  gap: 14px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--paper-raised);
  padding: 20px;
  min-height: 260px;
  max-height: 480px;
  overflow-y: auto;
  margin-bottom: 16px;
}

.msg {
  font-size: 0.95rem;
  line-height: 1.55;
  max-width: 85%;
  padding: 10px 14px;
  border-radius: 4px;
}

.msg-assistant {
  align-self: flex-start;
  background: var(--accent-soft);
  color: var(--ink);
}

.msg-user {
  align-self: flex-end;
  background: var(--paper);
  border: 1px solid var(--line);
  color: var(--ink);
  white-space: pre-wrap;
}

/* Rendered markdown inside assistant replies */
.msg-assistant > :first-child {
  margin-top: 0;
}
.msg-assistant > :last-child {
  margin-bottom: 0;
}
.msg-assistant p {
  margin: 0 0 10px;
}
.msg-assistant ul,
.msg-assistant ol {
  margin: 0 0 10px;
  padding-left: 1.3em;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.msg-assistant li::marker {
  color: var(--accent);
}
.msg-assistant strong {
  font-weight: 600;
}
.msg-assistant a {
  color: var(--accent);
}
.msg-assistant code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--paper-raised);
  border: 1px solid var(--line);
  padding: 0.1em 0.4em;
  border-radius: 3px;
}
.msg-assistant pre {
  margin: 0 0 10px;
  padding: 10px 12px;
  background: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow-x: auto;
}
.msg-assistant pre code {
  background: none;
  border: none;
  padding: 0;
}

.chat-form {
  display: flex;
  gap: 10px;
}

#chat-input {
  flex: 1;
  font-family: var(--sans);
  font-size: 0.95rem;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--paper-raised);
  color: var(--ink);
}

#chat-input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

#send-btn {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 0 20px;
  border: none;
  border-radius: 4px;
  background: var(--accent);
  color: var(--paper-raised);
  cursor: pointer;
}

#send-btn:hover,
#send-btn:focus-visible {
  opacity: 0.9;
}

#send-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.limits {
  font-size: 0.8rem;
  color: var(--ink-faint);
  margin: 10px 0 0;
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}