:root {
  --bg: #0f1115;
  --panel: #171a21;
  --text: #e6e6e6;
  --muted: #8b8f98;
  --accent: #5b8cff;
  --ok: #4caf50;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 24px;
  border-bottom: 1px solid #22262e;
}

.logo { font-weight: 700; font-size: 20px; }
.logo span { color: var(--accent); }

nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 18px;
  font-size: 14px;
}
nav a:hover { color: var(--text); }

main { max-width: 960px; margin: 0 auto; padding: 24px; }

.hero h1 { font-size: 32px; margin-bottom: 8px; }
.hero p { color: var(--muted); margin-top: 0; }

.playground {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 20px;
  margin: 32px 0;
}

@media (max-width: 720px) {
  .playground { grid-template-columns: 1fr; }
}

.chat-window {
  background: var(--panel);
  border-radius: 10px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  min-height: 360px;
}

.chat-log { flex: 1; overflow-y: auto; margin-bottom: 12px; }

.msg {
  padding: 8px 12px;
  border-radius: 8px;
  margin: 6px 0;
  max-width: 80%;
  font-size: 14px;
}
.msg.bot { background: #232833; }
.msg.user { background: var(--accent); color: #fff; margin-left: auto; }

.chat-form { display: flex; gap: 8px; }
.chat-form input {
  flex: 1;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid #2a2f3a;
  background: #12151b;
  color: var(--text);
  outline: none;
}
.chat-form button {
  padding: 10px 16px;
  border-radius: 8px;
  border: none;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
}

.side-panel {
  background: var(--panel);
  border-radius: 10px;
  padding: 16px;
  font-size: 14px;
}
.side-panel h3 { margin-top: 0; font-size: 14px; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
.side-panel ul { list-style: none; padding: 0; margin: 0 0 16px; }
.side-panel li { margin: 6px 0; color: var(--muted); }
.side-panel li strong { color: var(--text); }

.about, .status {
  background: var(--panel);
  border-radius: 10px;
  padding: 20px;
  margin: 20px 0;
}
.about h2, .status h2 { margin-top: 0; font-size: 18px; }
.ok { color: var(--ok); font-weight: 600; }

footer {
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  padding: 24px;
  border-top: 1px solid #22262e;
}