:root {
  color-scheme: dark;
  --bg: #0b0e10;
  --panel: #111819;
  --panel-2: #182322;
  --line: #2a3936;
  --text: #f6f2e9;
  --muted: #a9b6ae;
  --green: #42d69b;
  --blue: #74a5ff;
  --amber: #f1be57;
  --coral: #ff7f64;
}

* { box-sizing: border-box; }

html { min-height: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 85% 8%, rgba(255, 127, 100, 0.16), transparent 28%),
    radial-gradient(circle at 14% 18%, rgba(66, 214, 155, 0.15), transparent 34%),
    linear-gradient(135deg, #0b0e10 0%, #111817 48%, #10131a 100%);
  color: var(--text);
}

button,
textarea { font: inherit; }

.shell {
  width: min(1120px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 40px 0;
}

.hero {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: flex-end;
  margin-bottom: 28px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--green);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

h1 {
  margin: 0;
  font-size: clamp(34px, 6vw, 64px);
  line-height: 0.95;
  letter-spacing: 0;
}

.lede {
  max-width: 680px;
  margin: 18px 0 0;
  color: #dce5dc;
  font-size: 18px;
  line-height: 1.55;
}

.demo-link,
.composer button,
.prompts button {
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text);
  background: var(--panel-2);
  text-decoration: none;
  cursor: pointer;
}

.demo-link {
  flex: 0 0 auto;
  padding: 12px 16px;
}

.workspace {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 18px;
  min-height: 620px;
}

.prompts {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.prompts button {
  padding: 14px;
  text-align: left;
  color: #e2eadf;
}

.prompts button:hover,
.demo-link:hover,
.composer button:hover {
  border-color: var(--green);
}

.chat-panel {
  display: grid;
  grid-template-rows: 1fr auto;
  min-height: 620px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(17, 24, 25, 0.9);
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.24);
}

.messages {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 20px;
  overflow: auto;
}

.message {
  max-width: 78%;
  padding: 14px 16px;
  border-radius: 12px;
  line-height: 1.5;
  white-space: pre-wrap;
}

.message.assistant {
  align-self: flex-start;
  background: #172221;
  border: 1px solid var(--line);
}

.message.user {
  align-self: flex-end;
  background: #245f4c;
}

.meta {
  margin-top: 8px;
  color: var(--muted);
  font-size: 12px;
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  padding: 16px;
  border-top: 1px solid var(--line);
  background: #0e1415;
}

textarea {
  width: 100%;
  resize: vertical;
  min-height: 72px;
  max-height: 180px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #0a1010;
  color: var(--text);
  outline: none;
}

textarea:focus { border-color: var(--blue); }

.composer button {
  width: 96px;
  background: var(--green);
  color: #061713;
  font-weight: 800;
}

@media (max-width: 760px) {
  .shell { width: min(100vw - 24px, 1120px); padding: 24px 0; }
  .hero { display: block; }
  .demo-link { display: inline-block; margin-top: 18px; }
  .workspace { grid-template-columns: 1fr; min-height: 0; }
  .prompts { display: grid; grid-template-columns: 1fr; }
  .chat-panel { min-height: 560px; }
  .message { max-width: 92%; }
  .composer { grid-template-columns: 1fr; }
  .composer button { width: 100%; height: 44px; }
}