:root {
  color-scheme: light;
  --bg: #e6eef1;
  --ink: #14232c;
  --muted: #5d717c;
  --line: #d2dee4;
  --panel: #f5f8f9;
  --paper: #ffffff;
  --accent: #0c6e73;
  --accent-ink: #f4fffe;
  --soft: #e5f3f3;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.55 "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

button, input { font: inherit; }

.app {
  height: 100%;
  display: grid;
  grid-template-columns: 280px 1fr;
}

.side {
  padding: 22px 18px;
  border-right: 1px solid var(--line);
  background: var(--panel);
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
}

.brand svg {
  width: 36px;
  height: 36px;
  color: var(--accent);
  flex: none;
}

.brand strong { display: block; font-size: 18px; }
.brand p, .top p, .sync { margin: 0; color: var(--muted); font-size: 13px; }

.side h2 {
  margin: 26px 0 8px;
  font-size: 13px;
  font-weight: 650;
  letter-spacing: 0.04em;
}

#docs {
  list-style: none;
  margin: 0;
  padding: 0;
  overflow: auto;
  flex: 1;
}

#docs li {
  padding: 7px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
}

.sync { margin-top: 16px; }
.sync code, .msg code {
  font-family: Consolas, "Sarasa Mono SC", monospace;
  font-size: 12px;
}

.chat {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  background: var(--paper);
}

.top {
  padding: 20px 28px 0;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
}
.top h1 { margin: 0 0 4px; font-size: 22px; font-weight: 650; }

#dev-toggle {
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  border-radius: 999px;
  padding: 8px 14px;
  cursor: pointer;
  flex: none;
}
#dev-toggle[aria-expanded="true"] {
  background: var(--accent);
  color: var(--accent-ink);
  border-color: var(--accent);
}

#developer[hidden],
#dev-editor[hidden],
#gate-form[hidden] { display: none !important; }
#developer {
  display: none;
  gap: 10px;
  margin: 14px 28px 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
}
#developer.open { display: grid; }
#developer label { display: grid; gap: 4px; font-size: 13px; color: var(--muted); }
#developer input, #developer textarea {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  font: inherit;
  color: var(--ink);
  background: var(--paper);
}
#developer textarea { min-height: 68px; resize: vertical; }
.dev-actions { display: flex; flex-wrap: wrap; gap: 8px; }
#learn-submit, #sync-learned {
  border-radius: 999px;
  padding: 8px 12px;
  cursor: pointer;
  border: 1px solid var(--line);
  background: var(--paper);
}
#learn-submit {
  background: var(--accent);
  color: var(--accent-ink);
  border-color: var(--accent);
}
#learn-status { margin: 0; min-height: 1.2em; font-size: 13px; }
#developer h2 { margin: 4px 0 0; font-size: 13px; }
#learned { list-style: none; margin: 0; padding: 0; }
#learned li {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  align-items: center;
  padding: 6px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
}
#learned button {
  border: 0;
  background: transparent;
  color: var(--accent);
  cursor: pointer;
}
.hint { margin: 0; color: var(--muted); font-size: 13px; }

.log {
  flex: 1;
  overflow: auto;
  padding: 18px 28px 12px;
}

.empty p { color: var(--muted); margin: 8px 0 12px; }

.examples { display: flex; flex-wrap: wrap; gap: 8px; }

.examples button, .composer button, #send {
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  border-radius: 999px;
  padding: 8px 12px;
  cursor: pointer;
}

.examples button:hover { border-color: var(--accent); color: var(--accent); }

.msg { max-width: 740px; margin: 0 0 16px; }
.msg.user { margin-left: auto; }
.msg .bubble {
  padding: 10px 14px;
  border-radius: 14px;
  white-space: pre-wrap;
}
.msg.user .bubble { background: var(--accent); color: var(--accent-ink); }
.msg.bot .bubble { background: var(--soft); }
.sources { margin: 6px 0 0; color: var(--muted); font-size: 12px; }

.composer {
  display: flex;
  gap: 8px;
  padding: 12px 28px 18px;
  border-top: 1px solid var(--line);
}

.composer input {
  flex: 1;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 10px 14px;
  background: var(--paper);
  color: var(--ink);
}

.composer input:focus, .examples button:focus-visible, #send:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

#send {
  background: var(--accent);
  color: var(--accent-ink);
  border-color: var(--accent);
}

#send:disabled { opacity: 0.55; cursor: default; }

.sr {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
}

@media (max-width: 800px) {
  .app { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
  .side { border-right: 0; border-bottom: 1px solid var(--line); }
  #docs { display: flex; gap: 12px; overflow: auto; flex: none; }
  #docs li { border: 0; white-space: nowrap; }
  .sync { display: none; }
  .top, .log, .composer { padding-left: 16px; padding-right: 16px; }
  #developer { margin-left: 16px; margin-right: 16px; }
}