.message-audio {
      width: min(62vw, 286px);
      height: 38px;
      margin-top: 7px;
      display: block;
      color-scheme: light;
    }
    .bubble.system {
      align-self: center;
      max-width: 92%;
      padding: 7px 12px;
      border-radius: 999px;
      color: var(--mist);
      background: rgba(255, 255, 252, .38);
      font-size: 12px;
      text-align: center;
    }
    .qr-login-card {
      padding: 22px;
      border-radius: 26px;
      color: var(--ink);
      background: rgba(255, 255, 252, .68);
      box-shadow: var(--shadow);
    }
    .qr-login-card canvas,
    .qr-login-card .wechat-login-qr-image {
      width: 220px;
      height: 220px;
      max-width: 100%;
      margin: 6px auto 12px;
      display: block;
      background: #fff;
      border: 10px solid #fff;
    }
    .qr-title { color: var(--ink); font-size: 16px; font-weight: 700; line-height: 1.35; }
    .qr-note { margin-top: 6px; color: var(--mist); font-size: 13px; line-height: 1.45; }
    .wechat-link-preview {
      width: 100%; min-height: 58px; margin-top: 10px; padding: 9px 11px;
      border: 1px solid var(--hairline); border-radius: 14px; color: var(--ink-soft);
      background: rgba(255, 255, 252, .7); font-size: 12px; line-height: 1.4; resize: none;
    }
    .wechat-copy-button {
      margin-top: 10px; min-height: 42px; padding: 0 16px; border: 0; border-radius: 999px;
      color: white; background: var(--aura-deep); font-weight: 650;
    }
    .wechat-copy-button.secondary {
      margin-left: 8px; color: var(--ink-soft); background: rgba(255, 255, 252, .72);
      border: 1px solid var(--hairline);
    }
    .composer {
      position: relative;
      z-index: 30;
      margin: 0 12px max(10px, env(safe-area-inset-bottom));
      padding: 6px 6px 6px 17px;
      display: grid;
      grid-template-columns: 44px 44px 44px 44px minmax(0, 1fr) 62px;
      align-items: end;
      gap: 7px;
      border: 1px solid rgba(31, 51, 46, .12);
      border-radius: 29px;
      background: rgba(255, 255, 252, .78);
      box-shadow: 0 16px 44px rgba(25, 37, 34, .10);
      backdrop-filter: blur(22px) saturate(1.08);
    }
    .composer-tool {
      width: 44px;
      height: 44px;
      margin-bottom: 3px;
      display: inline-grid;
      place-items: center;
      border: 0;
      border-radius: 50%;
      color: var(--ink-soft);
      background: transparent;
      cursor: pointer;
    }
    .composer-tool:hover { color: var(--ink); background: var(--aura-wash); }
    .composer-tool svg { width: 20px; height: 20px; display: block; }
    .composer-tool.recording { color: #a14444; background: rgba(161,68,68,.09); }
    .live-voice-button.recording { color: #fff; background: var(--aura-deep); }
    .live-voice-button.connecting { color: var(--aura-deep); background: var(--aura-wash); }
    .composer-tool:disabled { opacity: .38; cursor: default; }
    .voice-mode-button {
      width: 44px;
      min-width: 44px;
      padding: 0;
      font-size: 14px;
      font-weight: 650;
    }
    .voice-mode-button svg { width: 19px; height: 19px; }
    .attachment-input { position: absolute; width: 1px; height: 1px; overflow: hidden; opacity: 0; pointer-events: none; }
    .attachment-strip {
      grid-column: 1 / -1;
      min-width: 0;
      display: flex;
      gap: 8px;
      overflow-x: auto;
    }
    .attachment-strip:empty { display: none; }
    .attachment-chip {
      min-width: 0;
      max-width: 210px;
      height: 42px;
      padding: 4px 9px 4px 5px;
      display: flex;
      align-items: center;
      gap: 8px;
      border: 1px solid var(--hairline);
      border-radius: 13px;
      color: var(--ink-soft);
      background: rgba(255,255,252,.60);
      font-size: 11px;
    }
    .attachment-chip img { width: 32px; height: 32px; flex: 0 0 32px; border-radius: 9px; object-fit: cover; }
    .attachment-chip span { min-width: 0; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
    .attachment-chip button { width: 24px; height: 24px; flex: 0 0 24px; border: 0; border-radius: 50%; color: var(--mist); background: transparent; }
    .composer-status { grid-column: 1 / -1; min-height: 0; color: var(--mist); font-size: 10.5px; }
    .composer-status:empty { display: none; }
    .learning-sheet {
      position: fixed; z-index: 82; inset: 0; overflow: auto; color: var(--ink);
      background:
        radial-gradient(circle at 86% 6%, rgba(107,104,180,.12), transparent 29%),
        linear-gradient(145deg, #fbfaf6, #f1f2f0 72%);
    }
    .learning-sheet[hidden] { display: none; }
    .learning-head {
      min-height: 70px; padding: max(12px, env(safe-area-inset-top)) 18px 8px 22px;
      display: flex; align-items: center; justify-content: space-between;
      border-bottom: 1px solid var(--hairline);
    }
    .learning-head-copy { display: grid; gap: 3px; }
    .learning-head-copy strong { font-size: 18px; font-weight: 620; letter-spacing: -.02em; }
    .learning-head-copy span { color: var(--mist); font-size: 11px; }
    .learning-body { width: min(100%, 980px); margin: 0 auto; padding: 30px 20px 90px; }
    .learning-intro { max-width: 620px; }
    .learning-kicker { margin: 0 0 11px; color: var(--aura); font-size: 10px; letter-spacing: .18em; }
    .learning-intro h2 { margin: 0; font-size: clamp(30px, 7vw, 52px); font-weight: 400; line-height: 1.1; letter-spacing: -.05em; }
    .learning-intro p:last-child { margin: 16px 0 0; color: var(--ink-soft); font-size: 14px; line-height: 1.75; }
    .course-grid { margin-top: 34px; display: grid; gap: 14px; }
    .course-card {
      display: grid; gap: 20px; min-height: 190px; padding: 22px; border: 1px solid var(--hairline);
      border-radius: 25px; background: rgba(255,255,252,.62); box-shadow: 0 20px 50px rgba(28,28,38,.045);
    }
    .course-meta { display: flex; align-items: center; justify-content: space-between; gap: 14px; }
    .course-level { color: var(--aura); font-size: 10px; letter-spacing: .13em; }
    .course-state { color: var(--mist); font-size: 11px; }
    .course-card h3 { margin: 0; font-size: 24px; font-weight: 500; letter-spacing: -.035em; }
    .course-card p { margin: 8px 0 0; color: var(--ink-soft); font-size: 13px; line-height: 1.65; }
    .classroom-roster { display: flex; flex-wrap: wrap; gap: 8px; }
    .roster-chip { padding: 7px 10px; border: 1px solid var(--hairline); border-radius: 999px; color: var(--ink-soft); background: rgba(255,255,255,.58); font-size: 11px; }
    .classroom-controls { display: flex; align-items: center; gap: 9px; }
    .classroom-primary, .classroom-secondary {
      min-height: 42px; border-radius: 21px; padding: 0 17px; font: inherit; font-size: 12px; font-weight: 650; cursor: pointer;
    }
    .classroom-primary { border: 0; color: #fff; background: var(--aura-deep); }
    .classroom-secondary { border: 1px solid var(--hairline); color: var(--ink); background: transparent; }
    .classroom-primary:disabled, .classroom-secondary:disabled { opacity: .38; cursor: default; }
    .classroom-runtime { min-height: 18px; color: var(--mist); font-size: 11px; }
    .mention-panel {
      position: fixed;
      z-index: 50;
      left: max(12px, env(safe-area-inset-left));
      right: max(12px, env(safe-area-inset-right));
      bottom: var(--baize-mention-panel-bottom);
      max-height: min(248px, 42vh);
      overflow: auto;
      border: 1px solid var(--hairline);
      border-radius: 20px;
      background: rgba(249, 249, 246, .96);
      box-shadow: var(--shadow);
      backdrop-filter: blur(22px);
    }
    .mention-panel[hidden] { display: none; }
    .mention-option {
      width: 100%; min-height: 48px; border: 0; padding: 9px 12px; display: flex;
      align-items: center; gap: 11px; background: transparent; color: var(--ink); text-align: left;
    }
    .mention-option:hover { background: var(--aura-wash); }
    .mention-avatar { flex: 0 0 auto; }
    .mention-main { min-width: 0; display: grid; gap: 2px; }
    .mention-label { font-size: 14px; font-weight: 650; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .mention-note { color: var(--mist); font-size: 11px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    textarea {
      width: 100%; min-height: 46px; max-height: 132px; resize: none; border: 0; padding: 12px 0 9px;
      color: var(--ink); background: transparent; font-size: 16px; line-height: 1.45; outline: none;
    }
    textarea::placeholder { color: #8c9491; }
    .send {
      width: 62px; height: 44px; min-height: 44px; margin-bottom: 2px; border: 0; border-radius: 22px;
      color: #f8faf7; background: var(--aura-deep); cursor: pointer;
    }
    .send-label {
      display: block; font-size: 12px; font-weight: 650; letter-spacing: .08em;
    }
    .send:disabled { color: #8a9290; background: rgba(34, 48, 45, .09); cursor: default; }
    .error { color: var(--danger); }
    button:focus-visible,
    textarea:focus-visible {
      outline: 2px solid rgba(107, 104, 180, .58);
      outline-offset: 3px;
    }
    .world-scrim {
      position: fixed; z-index: 70; inset: 0; background: rgba(20, 27, 25, .18);
      backdrop-filter: blur(6px); opacity: 1;
    }
    .world-scrim[hidden] { display: none; }
    .world-sheet {
      position: fixed; z-index: 80; inset: 0; overflow: auto; color: var(--ink);
      background:
        radial-gradient(circle at 82% 10%, rgba(125, 126, 190, .12), transparent 30%),
        linear-gradient(145deg, #faf8f1, #f1f3f0 72%);
    }
    .world-sheet[hidden] { display: none; }
    .world-head {
      min-height: 68px; padding: max(12px, env(safe-area-inset-top)) 15px 8px 20px;
      display: flex; align-items: center; justify-content: space-between;
    }
    .world-head span { color: var(--mist); font-size: 11px; letter-spacing: .18em; }
    .world-story { width: min(100%, 1180px); margin: 0 auto; padding: 4px 20px 80px; }
    .world-hero { position: relative; min-height: 440px; display: grid; align-items: end; overflow: hidden; }
    .world-hero-art {
      position: absolute; inset: 0 -32% 0 0; width: 132%; height: 100%; object-fit: cover; object-position: 58% 36%;
      mix-blend-mode: multiply; filter: saturate(.34) contrast(.96);
      -webkit-mask-image: radial-gradient(ellipse 82% 92% at 62% 42%, #000 0, #000 30%, rgba(0,0,0,.88) 40%, rgba(0,0,0,.44) 52%, rgba(0,0,0,.10) 64%, transparent 74%);
      mask-image: radial-gradient(ellipse 82% 92% at 62% 42%, #000 0, #000 30%, rgba(0,0,0,.88) 40%, rgba(0,0,0,.44) 52%, rgba(0,0,0,.10) 64%, transparent 74%);
    }
    .world-hero-copy { position: relative; z-index: 2; max-width: 620px; padding: 48px 0 58px; }
    .world-eyebrow { margin: 0 0 13px; color: var(--aura); font-size: 11px; letter-spacing: .18em; }
    .world-hero h2 {
      margin: 0; max-width: 560px; font-size: clamp(32px, 8.2vw, 68px); font-weight: 390;
      letter-spacing: -.055em; line-height: 1.08;
    }
    .world-lead { margin: 22px 0 0; max-width: 520px; color: var(--ink-soft); font-size: 15px; line-height: 1.8; }
    .world-draft { margin: 14px 0 0; color: var(--mist); font-size: 11px; line-height: 1.6; }
    .world-section { padding: 64px 0 0; border-top: 1px solid var(--hairline); }
    .world-section + .world-section { margin-top: 64px; }
    .world-section-mark { color: var(--aura); font-size: 10px; letter-spacing: .2em; }
    .world-section h3 { margin: 18px 0 0; max-width: 720px; font-size: clamp(27px, 5vw, 42px); font-weight: 420; letter-spacing: -.04em; }
    .world-section p { max-width: 700px; margin: 18px 0 0; color: var(--ink-soft); font-size: 15px; line-height: 1.9; }
    .world-origin-grid { margin-top: 30px; display: grid; gap: 18px; }
    .world-origin-grid article { padding-top: 18px; border-top: 1px solid var(--hairline); }
    .world-origin-grid strong { display: block; font-size: 15px; font-weight: 620; }
    .world-origin-grid p { margin-top: 8px; font-size: 13px; line-height: 1.7; }
    @media (min-width: 760px) {
      .app { width: min(100%, 1040px); margin: 0 auto; }
      .topbar { padding-left: 24px; padding-right: 24px; }
      .messages { width: min(calc(100% - 48px), 900px); margin: 0 auto; padding: 18px 0 32px; }
      .composer { width: min(calc(100% - 48px), 820px); margin-left: auto; margin-right: auto; }
      .presence-stage { grid-template-columns: minmax(300px, 1fr) minmax(320px, .9fr); align-items: center; justify-items: stretch; }
      .presence-art { grid-column: 2; grid-row: 1; width: 100%; height: min(48vh, 470px); margin: 0; }
      .presence-copy { grid-column: 1; grid-row: 1; max-width: 520px; padding: 0 0 0 30px; text-align: left; }
      .presence-copy h1 { font-size: clamp(38px, 5vw, 52px); }
      .presence-copy p:last-child { margin-left: 0; }
      .world-sheet { inset: 10px 10px 10px auto; width: min(86vw, 980px); border-radius: 28px; box-shadow: var(--shadow); }
      .world-story { padding-left: 48px; padding-right: 48px; }
      .world-hero { min-height: 520px; }
      .world-hero-art { inset: 0 -8% 0 28%; width: 80%; }
      .world-origin-grid { grid-template-columns: repeat(3, 1fr); }
      .learning-sheet { inset: 10px 10px 10px auto; width: min(86vw, 980px); border-radius: 28px; box-shadow: var(--shadow); }
      .learning-body { padding-left: 48px; padding-right: 48px; }
      .course-grid { grid-template-columns: minmax(0, 1fr); }
    }
    @media (max-width: 430px) {
      .composer {
        grid-template-columns: 44px 44px 44px 44px minmax(0, 1fr) 58px;
        gap: 2px;
        padding-left: 6px;
        padding-right: 6px;
      }
      .composer-tool, .voice-mode-button {
        width: 44px;
        min-width: 44px;
        height: 44px;
        margin-bottom: 2px;
      }
      textarea::placeholder { font-size: 15px; }
      .send { width: 58px; height: 44px; min-height: 44px; margin-bottom: 2px; }
    }
    @media (min-width: 1120px) {
      .app { width: min(100%, 1180px); }
      .presence-copy { padding-left: 64px; }
      .world-sheet { inset: 14px 14px 14px auto; width: min(78vw, 1120px); }
      .world-story { padding-left: 72px; padding-right: 72px; }
    }
    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after { scroll-behavior: auto !important; transition-duration: 0s !important; animation-duration: 0s !important; }
    }