:root {
  --bg: #0e1218;
  --panel: #161b22;
  --panel-2: #1d242e;
  --border: #2a323d;
  --text: #e6edf3;
  --muted: #8b949e;
  --accent: #f80000;       /* Oracle red */
  --accent-soft: #ffe5e5;
  --user: #2f6feb;
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", sans-serif;
  font-size: 15px;
}

header {
  padding: 20px 28px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #1b212b 0%, var(--bg) 100%);
}
header h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.2px;
}
header h1::before {
  content: "";
  display: inline-block;
  width: 10px; height: 10px;
  background: var(--accent);
  border-radius: 2px;
  margin-right: 10px;
  transform: translateY(-2px);
}
header .sub { margin: 6px 0 0; color: var(--muted); font-size: 13px; }

main {
  display: grid;
  grid-template-columns: 300px 1fr;
  height: calc(100vh - 82px);
}

aside {
  border-right: 1px solid var(--border);
  padding: 18px;
  overflow-y: auto;
  background: var(--panel);
}
aside h2 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
  margin: 0 0 12px;
}
#docs-list { list-style: none; padding: 0; margin: 0 0 14px; }
#docs-list li {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 8px;
  font-size: 13px;
  background: var(--panel-2);
}
#docs-list .title { font-weight: 500; margin-bottom: 3px; }
#docs-list .meta  { color: var(--muted); font-size: 11px; }
#docs-list .muted { color: var(--muted); }
.lang-tag {
  display: inline-block;
  font-size: 10px;
  padding: 1px 5px;
  border-radius: 3px;
  background: var(--accent-soft);
  color: var(--accent);
  margin-left: 6px;
  vertical-align: 1px;
}

section#chat-pane {
  display: flex;
  flex-direction: column;
  min-width: 0;
}
#messages {
  flex: 1;
  overflow-y: auto;
  padding: 24px 40px;
}
.msg {
  max-width: 780px;
  margin: 0 auto 18px;
  padding: 14px 18px;
  border-radius: 8px;
  line-height: 1.55;
}
.msg.user {
  background: var(--user);
  color: white;
  border-bottom-right-radius: 2px;
  margin-left: auto;
}
.msg.assistant {
  background: var(--panel);
  border: 1px solid var(--border);
}
.msg.assistant .body ul { padding-left: 18px; }
.msg.assistant .sources {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px dashed var(--border);
  font-size: 12px;
  color: var(--muted);
}
.msg.assistant .sources strong { color: var(--text); }
.msg.assistant .sources ol { padding-left: 20px; margin: 4px 0 0; }

form#ask-form {
  display: flex;
  gap: 8px;
  padding: 16px 40px 20px;
  border-top: 1px solid var(--border);
  background: var(--panel);
}
form#ask-form input {
  flex: 1;
  padding: 12px 14px;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
}
form#ask-form input:focus { outline: 2px solid var(--accent); }
button {
  padding: 10px 18px;
  border: none;
  border-radius: 6px;
  background: var(--accent);
  color: white;
  font-weight: 600;
  cursor: pointer;
  font-size: 13px;
}
button:hover { filter: brightness(1.08); }
button:disabled { opacity: .5; cursor: wait; }
button.small { padding: 6px 10px; font-size: 12px; background: var(--panel-2); color: var(--text); border: 1px solid var(--border); }

.loading::after {
  content: "";
  display: inline-block;
  width: 10px; height: 10px;
  border: 2px solid var(--muted);
  border-top-color: transparent;
  border-radius: 50%;
  margin-left: 6px;
  animation: spin .8s linear infinite;
  vertical-align: -2px;
}
@keyframes spin { to { transform: rotate(360deg); } }