:root {
  --abyss: #061018;
  --deep: #0b1c28;
  --panel: rgba(10, 32, 44, 0.72);
  --line: rgba(146, 212, 196, 0.18);
  --foam: #d7f3e8;
  --mist: #9eb8b0;
  --sand: #e6d3ae;
  --kelp: #7dcea0;
  --bio: #5eead4;
  --coral: #e07a5f;
  --glow: rgba(94, 234, 212, 0.35);
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
  --radius: 22px;
  --font-display: "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --font-body: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  font-family: var(--font-body);
  color: var(--foam);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(45, 138, 140, 0.25), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(224, 122, 95, 0.12), transparent 40%),
    linear-gradient(180deg, #0a2230 0%, var(--abyss) 55%, #031015 100%);
  overflow: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: radial-gradient(circle at 50% 30%, black, transparent 80%);
  opacity: 0.35;
}

.app {
  height: 100vh;
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 18px;
  padding: 18px;
  position: relative;
  z-index: 1;
}

.sidebar, .stage, .drawer {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  backdrop-filter: blur(18px);
  box-shadow: var(--shadow);
}

.sidebar {
  display: flex;
  flex-direction: column;
  padding: 22px 20px 16px;
  overflow: hidden;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 18px;
}
.mark {
  width: 46px;
  height: 46px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(160deg, #163b48, #0c2430);
  border: 1px solid rgba(94, 234, 212, 0.35);
  box-shadow: 0 0 24px var(--glow);
  font-size: 22px;
}
.brand h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 28px;
  letter-spacing: 0.04em;
}
.brand p, .muted { margin: 2px 0 0; color: var(--mist); font-size: 13px; }

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border-radius: 999px;
  background: rgba(94, 234, 212, 0.1);
  color: var(--bio);
  font-size: 12px;
  margin-top: 10px;
}

.search {
  margin: 16px 0 12px;
  position: relative;
}
.search input, .composer input, .field input, .field textarea, .field select {
  width: 100%;
  border: 1px solid var(--line);
  background: rgba(4, 16, 22, 0.55);
  color: var(--foam);
  border-radius: 14px;
  padding: 12px 14px;
  font: inherit;
  outline: none;
}
.search input:focus, .composer input:focus, .field input:focus, .field textarea:focus {
  border-color: rgba(94, 234, 212, 0.55);
  box-shadow: 0 0 0 4px rgba(94, 234, 212, 0.08);
}

.chips, .sources { display: flex; flex-wrap: wrap; gap: 8px; }
.chip, .source {
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.03);
  color: var(--foam);
  border-radius: 999px;
  padding: 7px 11px;
  font-size: 12px;
  cursor: pointer;
}
.chip:hover, .source:hover { border-color: var(--bio); color: var(--bio); }

.library {
  margin-top: 16px;
  overflow: auto;
  padding-right: 4px;
  flex: 1;
}
.card {
  padding: 12px 12px 11px;
  border-radius: 16px;
  border: 1px solid transparent;
  cursor: pointer;
  margin-bottom: 8px;
}
.card:hover, .card.active { background: rgba(94, 234, 212, 0.06); border-color: var(--line); }
.card b { display: block; font-size: 14px; }
.card span { color: var(--mist); font-size: 12px; }
.kicker {
  color: var(--sand);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.sidebar-actions { display: flex; gap: 8px; margin-top: 12px; }
button, .btn {
  appearance: none;
  border: 0;
  cursor: pointer;
  font: inherit;
}
.btn {
  border-radius: 12px;
  padding: 10px 12px;
  color: var(--abyss);
  background: var(--bio);
  font-weight: 700;
}
.btn.ghost, .icon-btn {
  background: transparent;
  color: var(--foam);
  border: 1px solid var(--line);
}
.icon-btn { border-radius: 12px; padding: 10px 12px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.stage {
  display: flex;
  flex-direction: column;
  min-width: 0;
  position: relative;
  overflow: hidden;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 22px 0;
}
.sonar {
  display: flex;
  gap: 14px;
  align-items: center;
  color: var(--mist);
  font-size: 13px;
}
.ring {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--kelp);
  box-shadow: 0 0 0 0 rgba(125, 206, 160, 0.6);
  animation: ping 2.2s infinite;
}
@keyframes ping {
  70% { box-shadow: 0 0 0 12px rgba(125, 206, 160, 0); }
}

.thread {
  flex: 1;
  overflow: auto;
  padding: 18px 22px 8px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.bubble {
  max-width: min(760px, 92%);
  padding: 14px 16px;
  border-radius: 18px;
  line-height: 1.75;
  white-space: pre-wrap;
}
.bubble.user {
  align-self: flex-end;
  background: linear-gradient(160deg, #245c66, #16343c);
  border: 1px solid rgba(94, 234, 212, 0.2);
}
.bubble.bot {
  align-self: flex-start;
  background: rgba(6, 18, 24, 0.7);
  border: 1px solid var(--line);
}
.bubble h3 { margin: 0 0 8px; font-family: var(--font-display); font-size: 20px; }
.meta { margin-top: 10px; color: var(--mist); font-size: 12px; }

.empty {
  margin: auto;
  text-align: center;
  max-width: 520px;
}
.empty h2 {
  font-family: var(--font-display);
  font-size: 40px;
  margin: 0 0 8px;
}
.empty p { color: var(--mist); }

.composer {
  display: flex;
  gap: 10px;
  padding: 12px 22px 20px;
}
.composer input { flex: 1; padding: 14px 16px; }

.drawer {
  position: fixed;
  top: 18px;
  right: 18px;
  bottom: 18px;
  width: min(460px, 100vw - 36px);
  z-index: 5;
  padding: 20px;
  overflow: auto;
  transform: translateX(110%);
  transition: transform 0.28s ease;
}
.drawer.open { transform: translateX(0); }
.drawer h2 { font-family: var(--font-display); margin: 0 0 8px; }
.gate {
  position: fixed;
  inset: 0;
  z-index: 8;
  display: none;
  place-items: center;
  background: rgba(4, 12, 16, 0.55);
}
.gate.open { display: grid; }
.gate-card {
  width: min(400px, calc(100vw - 36px));
  padding: 22px;
  border-radius: var(--radius);
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.gate-card h2 { font-family: var(--font-display); margin: 0 0 8px; }
.gate-error { color: var(--coral); font-size: 13px; min-height: 1.2em; }
.field { margin: 12px 0; }
.field label { display: block; margin-bottom: 6px; color: var(--mist); font-size: 13px; }
.field textarea { min-height: 110px; resize: vertical; }
.row { display: flex; gap: 8px; flex-wrap: wrap; }

.waves {
  position: fixed;
  left: 0;
  right: 0;
  bottom: -20px;
  height: 140px;
  pointer-events: none;
  z-index: 0;
  opacity: 0.45;
}

@media (max-width: 900px) {
  body { overflow: auto; }
  .app {
    grid-template-columns: 1fr;
    height: auto;
    min-height: 100vh;
  }
  .sidebar { height: auto; max-height: 42vh; }
  .stage { min-height: 64vh; }
}