:root {
  color-scheme: dark;
  --ink: #f2eee5;
  --muted: #96958e;
  --line: #30302e;
  --surface: #181817;
  --accent: #d7ff43;
  --heiwa: #9ddcff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px),
    #111110;
  background-size: 100% 42px;
  font-family: Arial, Helvetica, sans-serif;
}

button, input, textarea, select { font: inherit; }

.shell { width: min(1180px, calc(100% - 32px)); margin: 0 auto; padding: 28px 0 64px; }
.masthead, .feed-heading, .composer-footer { display: flex; align-items: center; justify-content: space-between; }
.masthead { border-bottom: 1px solid var(--line); padding-bottom: 20px; }
.eyebrow, .index, label > span, .feed-heading { color: var(--muted); font: 11px/1.2 monospace; letter-spacing: .12em; }
h1 { margin: 4px 0 0; font: 800 clamp(42px, 8vw, 78px)/.85 Arial, sans-serif; letter-spacing: -.06em; }
.presence { display: flex; gap: 9px; align-items: center; color: var(--muted); font-size: 13px; }
.presence-dot { width: 8px; height: 8px; border-radius: 50%; background: #6c6b66; }
.presence-dot.online { background: var(--accent); box-shadow: 0 0 16px var(--accent); }
.intro { padding: clamp(44px, 9vw, 96px) 0; max-width: 720px; }
.intro h2 { font-size: clamp(34px, 6vw, 64px); line-height: .98; letter-spacing: -.045em; margin: 16px 0 20px; }
.intro > p:last-child { color: #b9b7af; font-size: 17px; line-height: 1.55; max-width: 600px; }
.forum { border: 1px solid var(--line); background: rgba(24,24,23,.88); }
.feed-heading { padding: 14px 18px; border-bottom: 1px solid var(--line); }
.feed-actions { display: flex; align-items: center; gap: 14px; }
.quiet-button { color: var(--muted); background: none; border: 0; cursor: pointer; }
.quiet-button:hover { color: var(--ink); }
.latest-button { color: #111; background: var(--accent); border: 0; padding: 7px 10px; cursor: pointer; font: 11px monospace; }
.messages { list-style: none; padding: 0; margin: 0; max-height: min(72vh, 760px); min-height: 220px; overflow-y: auto; scrollbar-gutter: stable; overscroll-behavior: contain; }
.message { display: grid; grid-template-columns: 120px 1fr auto; gap: 18px; padding: 20px 18px; border-bottom: 1px solid var(--line); }
.message:last-child { border-bottom: 0; }
.message-author { font-weight: 700; overflow-wrap: anywhere; }
.message.heiwa .message-author { color: var(--heiwa); }
.message-text { margin: 0; line-height: 1.5; white-space: pre-wrap; overflow-wrap: anywhere; }
.message-time { color: var(--muted); font: 11px/1.4 monospace; }
.empty { color: var(--muted); padding: 42px 18px; margin: 0; text-align: center; }
.composer { margin-top: 16px; border: 1px solid var(--line); background: var(--surface); padding: 18px; }
.composer label { display: block; }
.message-field { margin-top: 18px; }
input, textarea, select { display: block; width: 100%; color: var(--ink); background: transparent; border: 0; border-bottom: 1px solid #444440; border-radius: 0; padding: 10px 0; outline: none; resize: vertical; }
input:focus, textarea:focus, select:focus { border-color: var(--accent); }
select option { color: #111; }
.composer-footer { min-height: 48px; margin-top: 14px; gap: 16px; }
#form-status { color: var(--muted); font-size: 13px; margin: 0; }
.send { border: 0; background: var(--accent); color: #111; padding: 13px 18px; font-weight: 800; cursor: pointer; }
.send:disabled { opacity: .45; cursor: wait; }
.send span { margin-left: 18px; }

.teacher { margin-top: 14px; border: 1px solid #46501f; background: linear-gradient(145deg, rgba(215,255,67,.06), rgba(24,24,23,.96) 35%); padding: 11px 14px; font-size: 13px; }
.teacher-heading, .inspector-heading, .teacher-actions, .batch-footer, .tree-head { display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.teacher > summary { cursor: pointer; list-style: none; }
.teacher > summary::-webkit-details-marker { display: none; }
.teacher > summary::before { content: '＋'; color: var(--accent); font: 16px monospace; }
.teacher[open] > summary::before { content: '−'; }
.trainer-title { display: flex; align-items: baseline; gap: 12px; }
.trainer-meta { display: flex; align-items: center; gap: 10px; margin-left: auto; }
.trainer-state { color: var(--heiwa); font: 11px monospace; }
.teacher h3 { margin: 0; font-size: 16px; letter-spacing: -.01em; }
.trainer-counter { color: var(--accent); border: 1px solid #46501f; padding: 6px 9px; font: 10px monospace; white-space: nowrap; }
.inquiry-card { margin: 14px 0; padding: 10px 12px; border-left: 2px solid var(--heiwa); background: rgba(157,220,255,.055); }
.inquiry-card span, fieldset legend, .teacher label > span { color: var(--muted); font: 9px/1.2 monospace; letter-spacing: .09em; }
.inquiry-card strong { display: block; margin-top: 5px; color: var(--heiwa); font-size: 15px; }
.inquiry-card p { margin: 5px 0 0; color: #b9b7af; font-size: 12px; }
.tutor-journal { margin: 14px 0 0; border: 1px solid #34434a; background: rgba(157,220,255,.035); }
.tutor-journal > summary { display: flex; justify-content: space-between; gap: 12px; padding: 9px 10px; cursor: pointer; color: var(--heiwa); font: 700 10px monospace; letter-spacing: .07em; }
.tutor-journal > summary small { color: var(--muted); font-weight: 400; letter-spacing: 0; text-align: right; }
.tutor-explainer { margin: 0; padding: 0 10px 9px; color: var(--muted); font-size: 11px; line-height: 1.4; }
.tutor-lessons { display: grid; gap: 10px; max-height: 480px; overflow-y: auto; margin: 0; padding: 0 10px 10px; list-style: none; }
.tutor-exchange { display: grid; gap: 7px; border-top: 1px solid var(--line); padding-top: 10px; }
.tutor-exchange:first-child { border-top: 0; padding-top: 0; }
.tutor-turn { width: min(82%, 720px); border: 1px solid var(--line); padding: 9px 11px; background: rgba(255,255,255,.018); }
.tutor-turn > strong { display: block; margin-bottom: 4px; color: var(--muted); font: 9px monospace; letter-spacing: .06em; }
.tutor-turn > p { margin: 0; line-height: 1.45; font-size: 13px; }
.tutor-turn > small { display: block; margin-top: 5px; color: var(--muted); font-size: 10px; line-height: 1.35; }
.heiwa-turn { justify-self: start; border-color: #34434a; }
.heiwa-turn > strong { color: var(--heiwa); }
.qwen-turn { justify-self: end; border-color: #4b532c; }
.qwen-turn > strong { color: var(--accent); }
.memory-turn { justify-self: center; width: min(92%, 800px); border-style: dashed; color: #b9b7af; }
.thinking > p { color: var(--muted); }
.interactive-teaching { display: flex; gap: 12px; margin-top: 10px; padding: 9px 11px; border-left: 2px solid var(--accent); background: rgba(215,255,67,.035); font-size: 11px; line-height: 1.4; }
.interactive-teaching strong { flex: 0 0 auto; color: var(--accent); font: 9px/1.5 monospace; letter-spacing: .08em; }
.interactive-teaching span { color: var(--muted); }
.tutor-details { margin: 0 4%; padding: 7px 9px; border: 1px solid var(--line); color: #b9b7af; }
.tutor-details > summary { cursor: pointer; color: var(--muted); font: 9px monospace; letter-spacing: .06em; }
.tutor-details p { margin: 6px 0; font-size: 11px; line-height: 1.4; }
.tutor-details p strong { color: var(--ink); }
.lesson-guide { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin: 0 0 12px; }
.lesson-guide p { margin: 0; padding: 8px 10px; border: 1px solid var(--line); }
.lesson-guide strong, .lesson-guide span { display: block; }
.lesson-guide strong { color: var(--accent); font: 9px monospace; letter-spacing: .08em; }
.lesson-guide span { margin-top: 4px; color: var(--muted); font-size: 11px; line-height: 1.35; }
.lesson-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 18px; }
.wide-field { grid-column: 1 / -1; }
.teacher input, .teacher textarea, .teacher select { padding: 6px 0; font-size: 13px; line-height: 1.3; }
.subject-field input { font-size: 15px; font-weight: 700; }
.lesson-section { border-top: 1px solid var(--line); padding-top: 9px; }
.lesson-section > summary { display: flex; justify-content: space-between; gap: 12px; cursor: pointer; color: var(--ink); font: 700 10px/1.25 monospace; letter-spacing: .07em; }
.lesson-section > summary span { color: var(--muted); font-weight: 400; letter-spacing: 0; text-align: right; }
.lesson-section[open] > summary { color: var(--accent); }
.lesson-section-body { margin-top: 10px; }
fieldset { min-width: 0; margin: 0; padding: 0; border: 0; }
.repeatable-list { display: grid; gap: 6px; margin-top: 5px; }
.repeatable-item { display: grid; grid-template-columns: 1fr auto; gap: 7px; align-items: start; }
.response-pair { grid-template-columns: minmax(180px, .8fr) minmax(240px, 1.2fr) auto; }
.remove-item { width: 26px; height: 26px; margin-top: 3px; border: 1px solid #4b3535; background: transparent; color: #d89898; cursor: pointer; }
.add-item, .quiet-action { margin-top: 6px; border: 1px solid #444440; background: transparent; color: var(--muted); padding: 6px 9px; cursor: pointer; font: 9px monospace; letter-spacing: .07em; }
.add-item:hover, .quiet-action:hover { color: var(--ink); border-color: var(--accent); }
.suggested-field { border: 1px dashed #4c5820; padding: 10px; }
.teacher-actions { margin-top: 12px; border-top: 1px solid var(--line); padding-top: 10px; }
.teacher-alternatives { display: flex; gap: 8px; flex-wrap: wrap; }
.quiet-action.danger { color: #d89898; }
#lesson-status, #batch-status { color: var(--muted); font-size: 13px; margin: 0; flex: 1; }
.knowledge-inspector { margin-top: 20px; border-top: 1px solid var(--line); padding-top: 16px; }
.knowledge-inspector h4 { margin: 4px 0 0; font-size: 18px; }
.knowledge-search { display: flex; gap: 10px; width: min(460px, 55%); align-items: flex-end; }
.knowledge-search .quiet-action { margin: 0; }
.knowledge-tree { margin-top: 10px; border: 1px solid var(--line); padding: 10px; color: #b9b7af; }
.knowledge-tree details { border-top: 1px solid var(--line); padding: 8px 0; }
.knowledge-tree summary { color: var(--ink); cursor: pointer; font-weight: 700; }
.knowledge-tree ul { margin: 10px 0 0; padding-left: 24px; }
.knowledge-tree li { margin: 7px 0; line-height: 1.45; }
.tree-head { padding-bottom: 14px; }
.tree-head strong { color: var(--heiwa); font-size: 22px; }
.batch-panel { margin-top: 16px; border-top: 1px solid var(--line); padding-top: 12px; }
.batch-panel summary { cursor: pointer; color: var(--accent); font: 10px monospace; letter-spacing: .08em; }
.batch-panel > p { color: var(--muted); }
.batch-lessons { display: grid; gap: 14px; }
.batch-lesson { border: 1px solid var(--line); padding: 10px; background: rgba(255,255,255,.015); }
.batch-lesson-heading { display: flex; align-items: center; justify-content: space-between; color: var(--heiwa); font: 11px monospace; letter-spacing: .09em; }
.batch-lesson-heading .remove-item { margin: 0; }
.batch-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 14px; margin-top: 5px; }
.batch-footer { margin-top: 12px; }
.secondary-send { background: var(--heiwa); }

@media (max-width: 620px) {
  .shell { width: min(100% - 20px, 920px); padding-top: 16px; }
  .message { grid-template-columns: 1fr auto; gap: 8px 12px; }
  .message-text { grid-column: 1 / -1; }
  .intro { padding: 28px 0; }
  .intro h2 { font-size: 34px; }
  .messages { min-height: 320px; max-height: 62svh; }
  .teacher { padding: 10px; margin-top: 10px; }
  .teacher-heading { align-items: flex-start; gap: 8px; }
  .trainer-title { display: block; }
  .teacher h3 { margin-top: 3px; font-size: 14px; }
  .trainer-state { display: block; max-width: 170px; text-align: right; font-size: 10px; }
  .trainer-counter { display: none; }
  .teacher input, .teacher textarea, .teacher select, .composer input, .composer textarea { font-size: 16px; }
  .add-item, .quiet-action, .remove-item { min-height: 40px; }
  .remove-item { width: 40px; }
  .lesson-grid { grid-template-columns: 1fr; }
  .lesson-guide { grid-template-columns: 1fr; }
  .batch-grid { grid-template-columns: 1fr; }
  .wide-field { grid-column: auto; }
  .response-pair { grid-template-columns: 1fr auto; }
  .response-pair textarea { grid-column: 1 / 2; }
  .inspector-heading, .teacher-actions, .batch-footer { align-items: stretch; flex-direction: column; }
  .knowledge-search { width: 100%; }
  .tutor-journal > summary { display: grid; }
  .tutor-journal > summary small { text-align: left; }
  .tutor-turn { width: 94%; }
  .memory-turn { width: 100%; }
  .interactive-teaching { display: grid; }
}

@media (prefers-reduced-motion: no-preference) {
  .message { animation: arrive .25s ease-out; }
  @keyframes arrive { from { opacity: 0; transform: translateY(5px); } }
}