:root {
  --bg: #f5f0eb;
  --surface: #faf7f2;
  --ink: #2c2c2c;
  --ink-light: #6b6560;
  --ink-faint: #a8a099;
  --accent: #8b7355;
  --moss: #7a8b6f;
  --clay: #b8805a;
  --stone: #d4cdc4;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: "Noto Sans JP", -apple-system, sans-serif;
  font-weight: 400;
  line-height: 1.7;
  color: var(--ink);
  background: var(--bg);
  overflow: hidden;
  height: 100vh;
}

header {
  padding: 1.5rem 2rem 0.5rem;
}

h1 {
  font-weight: 300;
  font-size: 1.3rem;
  letter-spacing: 0.04em;
}

main {
  display: flex;
  height: calc(100vh - 4rem);
  position: relative;
  z-index: 1;
}

/* Chat panel */
#chat-panel {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  padding: 1rem 1.5rem;
  overflow: hidden;
}

#messages {
  flex: 1;
  overflow-y: auto;
  padding-bottom: 1rem;
}

.msg { margin-bottom: 1.2rem; max-width: 100%; }
.msg-user { color: var(--ink); font-weight: 400; }
.msg-user::before { content: "› "; color: var(--accent); }

.msg-assistant {
  color: var(--ink-light);
  white-space: pre-wrap;
  word-wrap: break-word;
}

.msg-assistant code {
  background: var(--surface);
  padding: 0.1em 0.35em;
  border-radius: 2px;
  font-size: 0.88em;
  color: var(--moss);
}

.msg-assistant pre {
  background: var(--surface);
  padding: 0.8rem 1rem;
  margin: 0.5rem 0;
  overflow-x: auto;
  border-left: 2px solid var(--stone);
  line-height: 1.5;
}

.msg-assistant pre code { background: none; padding: 0; color: var(--ink); }

#chat-form {
  border-top: 1px solid var(--stone);
  padding-top: 1rem;
  background: var(--bg);
}

#chat-input {
  width: 100%;
  border: none;
  border-bottom: 1px solid var(--stone);
  background: transparent;
  font-family: inherit;
  font-size: 1rem;
  color: var(--ink);
  padding: 0.5rem 0;
  outline: none;
}

#chat-input::placeholder { color: var(--ink-faint); }
#chat-input:focus { border-bottom-color: var(--accent); }

/* Loading dots */
.loading span {
  display: inline-block;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--ink-faint);
  margin-right: 4px;
  animation: pulse 1.4s ease-in-out infinite;
}
.loading span:nth-child(2) { animation-delay: 0.2s; }
.loading span:nth-child(3) { animation-delay: 0.4s; }

@keyframes pulse {
  0%, 80%, 100% { opacity: 0.3; }
  40% { opacity: 1; }
}

/* Graph panel */
#graph-panel {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--stone);
  position: relative;
}

#graph-container { flex: 1; min-height: 0; }

.graph-empty {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  color: var(--ink-faint);
  font-size: 0.95rem;
}

.legend {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 0.8rem 1rem;
  font-size: 0.8rem;
  color: var(--ink-light);
}

.dot {
  display: inline-block;
  width: 8px; height: 8px;
  border-radius: 50%;
  margin-right: 3px;
  vertical-align: middle;
}

.legend-note { color: var(--ink-faint); }

/* Scenery */
body::before {
  content: "";
  position: fixed;
  bottom: 0; left: 0; right: 0;
  height: 18vh;
  background:
    linear-gradient(135deg, transparent 40%, var(--stone) 40%, var(--stone) 41%, transparent 41%),
    linear-gradient(160deg, transparent 55%, var(--stone) 55%),
    linear-gradient(200deg, transparent 50%, var(--stone) 50%);
  opacity: 0.12;
  pointer-events: none;
  z-index: 0;
}

body::after {
  content: "";
  position: fixed;
  top: 2rem; right: 4rem;
  width: 60px; height: 60px;
  border-radius: 50%;
  background: var(--stone);
  opacity: 0.15;
  pointer-events: none;
  z-index: 0;
}

.bamboo {
  position: fixed;
  bottom: 0;
  width: 2px;
  height: 35vh;
  background: var(--moss);
  opacity: 0.12;
  pointer-events: none;
  z-index: 0;
  transform-origin: bottom center;
  animation: sway 8s ease-in-out infinite;
}
.bamboo.b2 { height: 28vh; animation-delay: -2s; }
.bamboo.b3 { height: 22vh; animation-delay: -5s; }

@keyframes sway {
  0%, 100% { transform: rotate(0deg); }
  50% { transform: rotate(1.5deg); }
}

.msg-assistant blockquote {
  font-style: italic;
  color: var(--ink-faint);
  border-left: 2px solid var(--stone);
  padding-left: 0.8rem;
  margin: 0.3rem 0;
}

/* Markdown inline */
.msg-assistant strong { color: var(--ink); font-weight: 400; }
.msg-assistant em { font-style: italic; }

/* Viz toggle bar */
.viz-toggle {
  display: flex;
  gap: 0;
  padding: 0.5rem 1rem;
  border-bottom: 1px solid var(--stone);
}

.viz-toggle__btn {
  flex: 1;
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--stone);
  border-right: none;
  background: var(--surface);
  color: var(--ink-light);
  font-family: inherit;
  font-size: 0.8rem;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.viz-toggle__btn:last-child { border-right: 1px solid var(--stone); border-radius: 0 3px 3px 0; }
.viz-toggle__btn:first-child { border-radius: 3px 0 0 3px; }
.viz-toggle__btn--active { background: var(--bg); color: var(--ink); }
.viz-toggle__btn:hover:not(.viz-toggle__btn--active) { background: var(--bg); }

/* D3 SVG */
#viz-svg { width: 100%; height: 100%; }

.bloom-arc { cursor: pointer; transition: opacity 0.2s; }
.bloom-arc:hover { opacity: 0.8; }
.bloom-label { font-size: 0.7rem; fill: var(--ink-light); pointer-events: none; font-family: inherit; }

.dendrite-link { fill: none; }
.dendrite-node { cursor: pointer; }
.dendrite-label { font-size: 0.7rem; fill: var(--ink-light); pointer-events: none; font-family: inherit; }
.dendrite-gap-link { stroke-dasharray: 4 3; }

.ribbon-arc { fill: none; opacity: 0.5; }
.ribbon-arc:hover { opacity: 1; }
.ribbon-arc--gap { stroke-dasharray: 5 3; }
.ribbon-node { cursor: pointer; }
.ribbon-label { font-size: 0.7rem; fill: var(--ink-light); text-anchor: middle; pointer-events: none; font-family: inherit; }

.viz-tooltip {
  position: absolute;
  padding: 0.4rem 0.6rem;
  background: var(--surface);
  border: 1px solid var(--stone);
  border-radius: 3px;
  font-size: 0.75rem;
  color: var(--ink);
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.15s;
  z-index: 10;
  font-family: inherit;
}
.viz-tooltip--visible { opacity: 1; }