:root{
    --brand:#005CB4;
    --brand-dark:#004A91;
    --navy:#16263B;
    --slate:#3E5C76;
    --cloud:#F3F6F8;
    --paper:#FFFFFF;
    --ink:#182230;
    --muted:#62748B;
    --line:#DCE4EA;
    --amber:#E2A33D;
    --warning:#C5611F;
    --active:#B8392A;
    --recovery:#4A6A8A;
    --radius:14px;
    --sky-top:#CFEAF3;
    --sea-pale:#AEDCDC;
    --sea-mid:#3F93A0;
    --sea-deep:#0E5C68;
    --sun-glow:#FFEBC2;
    --bird-ink:#243B52;
    --font-display:'Big Shoulders Display',sans-serif;
    --font-body:'Source Sans 3',sans-serif;
    --font-mono:'IBM Plex Mono',monospace;
  }
  *{box-sizing:border-box;}
  html,body{margin:0;padding:0;}
  body{
    background:var(--cloud);
    color:var(--ink);
    font-family:var(--font-body);
    -webkit-font-smoothing:antialiased;
    padding-bottom:env(safe-area-inset-bottom);
  }
  .container{max-width:720px;margin:0 auto;}
  a{color:var(--brand);}
  :focus-visible{outline:3px solid #2563EB;outline-offset:2px;}

  /* ---------- Status bar ---------- */
  .status-bar{
    position:sticky;top:0;z-index:50;
    background:var(--brand);color:#fff;
    padding:14px 16px;
    display:flex;align-items:center;gap:12px;
    box-shadow:0 2px 8px rgba(0,0,0,.12);
    transition:background-color .35s ease;
  }
  .status-bar__text{flex:1;min-width:0;}
  .status-bar__label{
    font-family:var(--font-display);font-weight:900;
    text-transform:uppercase;letter-spacing:.02em;
    font-size:clamp(1.05rem,4.2vw,1.35rem);line-height:1.1;
  }
  .status-bar__meta{
    font-family:var(--font-mono);font-size:.7rem;
    opacity:.88;margin-top:2px;
    white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
  }
  .status-bar__btn{
    flex:0 0 auto;
    background:rgba(255,255,255,.16);
    border:1px solid rgba(255,255,255,.55);
    color:#fff;border-radius:8px;
    padding:7px 12px;font-family:var(--font-mono);
    font-size:.68rem;letter-spacing:.06em;text-transform:uppercase;
    cursor:pointer;
  }
  .status-bar__btn:hover{background:rgba(255,255,255,.28);}
  @media (prefers-reduced-motion:no-preference){
    .status-bar.is-active{animation:pulseBg 2.6s ease-in-out infinite;}
  }
  @keyframes pulseBg{0%,100%{filter:brightness(1);}50%{filter:brightness(1.18);}}

  .status-bar.is-loading{background:var(--slate);}
  .status-bar.is-error{background:var(--warning);}

  /* ---------- Header ---------- */
  .app-header{
    position:relative;overflow:hidden;text-align:center;
    margin:0 10px;border-radius:26px;
    padding:36px 18px 26px;
    box-shadow:0 10px 30px rgba(22,38,59,.12);
  }
  .app-header__scene{position:absolute;inset:0;z-index:0;pointer-events:none;}
  .app-header__scene svg{display:block;width:100%;height:100%;}
  .app-header__logo{
    position:relative;z-index:1;
    display:block;width:100%;max-width:380px;height:auto;margin:0 auto 8px;
  }
  .app-header__panel{
    position:relative;z-index:1;
    display:inline-block;margin:8px 0 0;padding:14px 20px 16px;
    max-width:540px;border-radius:18px;
    background:rgba(255,255,255,.64);
    backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
    border:1px solid rgba(255,255,255,.55);
  }
  .app-header__sub{
    font-family:var(--font-mono);font-size:.78rem;
    text-transform:uppercase;letter-spacing:.09em;
    color:var(--muted);margin-top:2px;
  }
  .app-header__desc{
    margin:12px auto 0;font-size:.96rem;line-height:1.5;
    color:var(--ink);max-width:520px;text-align:left;
  }
  .conn{
    display:inline-flex;align-items:center;gap:6px;
    font-family:var(--font-mono);font-size:.7rem;
    color:var(--muted);margin-top:10px;
  }
  .conn__dot{width:8px;height:8px;border-radius:50%;background:var(--brand);}
  .conn.is-offline .conn__dot{background:var(--warning);}

  .app-header__register{
    position:relative;z-index:1;
    display:block;width:100%;max-width:340px;margin:14px auto 0;
    padding:13px 16px;font-size:.92rem;
  }

  .howto{position:relative;z-index:1;margin-top:14px;border:1px solid var(--line);border-radius:10px;background:var(--paper);text-align:left;}
  .howto__label{
    padding:10px 14px;font-weight:600;font-size:.86rem;
    color:var(--muted);border-bottom:1px solid var(--line);
  }
  .howto .howto-body{padding:12px 14px 14px;font-size:.85rem;line-height:1.55;color:var(--slate);}

  /* ---------- Tabs ---------- */
  .tabs{display:flex;gap:8px;padding:18px 16px 4px;}
  .tab{
    flex:1;padding:11px 10px;border:1px solid var(--line);border-radius:10px;
    background:var(--paper);font-family:var(--font-mono);font-size:.72rem;
    text-transform:uppercase;letter-spacing:.06em;font-weight:700;
    color:var(--muted);cursor:pointer;transition:border-color .12s,color .12s,background .12s;
  }
  .tab.is-active{border-color:var(--brand);color:var(--brand);background:#EAF2FB;}
  .tab-badge{
    display:inline-block;margin-left:6px;min-width:16px;padding:1px 5px;
    border-radius:999px;background:var(--active);color:#fff;font-size:.62rem;font-weight:700;
    vertical-align:middle;
  }
  .panel[hidden]{display:none;}
  .panel-intro{padding:14px 16px 0;font-size:.92rem;line-height:1.5;color:var(--slate);}

  /* ---------- Building rail ---------- */
  .building-rail{
    display:flex;gap:10px;overflow-x:auto;
    padding:18px 16px 14px;scroll-snap-type:x mandatory;
    -webkit-overflow-scrolling:touch;
  }
  .building-tile{
    flex:0 0 88px;scroll-snap-align:start;
    background:var(--paper);border:1px solid var(--line);
    border-radius:var(--radius);padding:10px 6px;text-align:center;
    cursor:pointer;transition:transform .12s,border-color .12s,box-shadow .12s;
  }
  .building-tile:hover{transform:translateY(-2px);}
  .building-tile.is-active{border-color:var(--brand);box-shadow:inset 0 0 0 2px var(--brand);}
  .building-tile__num{font-family:var(--font-display);font-weight:900;font-size:1.7rem;color:var(--brand);line-height:1;}
  .building-tile__label{font-family:var(--font-mono);font-size:.6rem;text-transform:uppercase;color:var(--muted);letter-spacing:.06em;margin-top:2px;}
  .building-tile__time{font-size:.66rem;color:var(--muted);margin-top:6px;min-height:13px;}
  .building-tile__badge{
    display:inline-block;margin-top:4px;min-width:16px;
    padding:1px 5px;border-radius:999px;background:var(--amber);
    color:#2A1B00;font-family:var(--font-mono);font-size:.62rem;font-weight:700;
  }

  /* ---------- Feed / cards ---------- */
  .feed{display:flex;flex-direction:column;gap:12px;padding:4px 16px 110px;}
  .qa-list{display:flex;flex-direction:column;gap:12px;padding:14px 16px 110px;}
  .post-card,.qa-card{
    background:var(--paper);border:1px solid var(--line);
    border-radius:var(--radius);padding:14px 16px;
    animation:fadeIn .35s ease;
  }
  @keyframes fadeIn{from{opacity:0;transform:translateY(6px);}to{opacity:1;transform:translateY(0);}}
  .post-card__head,.qa-card__head{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:8px;}
  .post-card__area{
    font-family:var(--font-mono);font-size:.66rem;text-transform:uppercase;
    letter-spacing:.06em;padding:3px 8px;border-radius:6px;
    background:var(--brand);color:#fff;
  }
  .post-card__name{font-weight:700;}
  .post-card__time{margin-left:auto;font-family:var(--font-mono);font-size:.7rem;color:var(--muted);white-space:nowrap;}
  .post-card__message{white-space:pre-wrap;line-height:1.55;font-size:.97rem;}
  .photo-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(92px,1fr));gap:6px;margin-top:10px;}
  .photo-grid img{width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:8px;cursor:zoom-in;display:block;background:var(--cloud);}
  .photo-grid video{width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:8px;display:block;background:#000;}
  .photo-grid__demo{
    display:flex;align-items:center;justify-content:center;
    aspect-ratio:1/1;border-radius:8px;background:var(--cloud);
    border:1px dashed var(--line);font-size:1.3rem;color:var(--muted);
  }

  .empty-state{
    text-align:center;padding:48px 20px;color:var(--muted);
  }
  .empty-state__icon{font-size:2.2rem;}
  .empty-state p{margin:8px 0 0;font-size:.92rem;}

  /* ---------- Q&A specific ---------- */
  .qa-status{
    margin-left:auto;font-family:var(--font-mono);font-size:.64rem;text-transform:uppercase;
    letter-spacing:.05em;padding:3px 8px;border-radius:6px;white-space:nowrap;
  }
  .qa-status.is-open{background:var(--amber);color:#2A1B00;}
  .qa-status.is-answered{background:var(--brand);color:#fff;}
  .qa-card__question{font-size:.97rem;line-height:1.55;white-space:pre-wrap;}
  .qa-answer{
    margin-top:10px;padding:10px 12px;background:var(--cloud);
    border-left:3px solid var(--brand);border-radius:0 8px 8px 0;
  }
  .qa-answer__head{font-size:.8rem;margin-bottom:3px;display:flex;gap:8px;align-items:baseline;}
  .qa-answer__text{font-size:.92rem;line-height:1.5;white-space:pre-wrap;}
  .qa-reply-btn{
    margin-top:10px;background:none;border:1px solid var(--line);border-radius:8px;
    padding:7px 12px;font-size:.78rem;font-weight:700;color:var(--brand);cursor:pointer;
  }
  .qa-reply-btn:hover{border-color:var(--brand);}

  /* ---------- FAB ---------- */
  .fab{
    position:fixed;bottom:calc(20px + env(safe-area-inset-bottom));right:20px;
    width:60px;height:60px;border-radius:50%;
    background:var(--brand);color:#fff;border:none;
    font-size:2rem;line-height:1;
    box-shadow:0 6px 18px rgba(0,0,0,.28);cursor:pointer;
    display:flex;align-items:center;justify-content:center;z-index:40;
  }
  .fab:active{transform:scale(.94);}

  /* ---------- Modal ---------- */
  .modal-overlay{
    position:fixed;inset:0;background:rgba(10,20,30,.55);
    display:flex;align-items:flex-end;justify-content:center;
    z-index:100;opacity:0;pointer-events:none;transition:opacity .2s ease;
  }
  .modal-overlay.is-open{opacity:1;pointer-events:auto;}
  .modal{
    background:var(--paper);width:100%;max-width:520px;
    border-radius:18px 18px 0 0;max-height:92vh;overflow-y:auto;
    padding:20px 20px calc(20px + env(safe-area-inset-bottom));
    transform:translateY(24px);transition:transform .25s ease;
    position:relative;
  }
  .modal-overlay.is-open .modal{transform:translateY(0);}
  @media (min-width:600px){
    .modal-overlay{align-items:center;}
    .modal{border-radius:16px;max-height:88vh;}
  }
  .modal h2{
    font-family:var(--font-display);font-weight:800;text-transform:uppercase;
    letter-spacing:.02em;font-size:1.4rem;margin:0 0 4px;color:var(--brand);
  }
  .modal .modal-sub{font-size:.85rem;color:var(--muted);margin:0 0 16px;}
  .modal .modal-sub.modal-sub--quote{
    background:var(--cloud);border-radius:8px;padding:8px 10px;
    color:var(--ink);font-style:italic;white-space:pre-wrap;
  }
  .field{margin-bottom:14px;}
  .field label{display:block;font-weight:600;font-size:.86rem;margin-bottom:5px;}
  .field .hint{display:block;font-size:.76rem;color:var(--muted);margin-top:4px;}
  .field input,.field select,.field textarea{
    width:100%;padding:11px 12px;border:1px solid var(--line);
    border-radius:9px;font-family:var(--font-body);font-size:1rem;
    background:#fff;color:var(--ink);
  }
  .field textarea{resize:vertical;min-height:90px;}
  .field input:focus,.field select:focus,.field textarea:focus{border-color:var(--brand);}
  .charcount{font-family:var(--font-mono);font-size:.7rem;color:var(--muted);text-align:right;margin-top:3px;}

  .photo-input-btn{
    display:inline-flex;align-items:center;gap:6px;
    padding:10px 14px;border:1px dashed var(--line);border-radius:9px;
    background:var(--cloud);font-size:.88rem;font-weight:600;cursor:pointer;
    color:var(--slate);
  }
  .preview-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(72px,1fr));gap:8px;margin-top:10px;}
  .preview-item{position:relative;}
  .preview-item img,.preview-item video{width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:8px;background:var(--cloud);}
  .preview-item button{
    position:absolute;top:-6px;right:-6px;width:22px;height:22px;border-radius:50%;
    border:none;background:var(--active);color:#fff;font-size:.85rem;line-height:1;cursor:pointer;
  }

  .modal-actions{display:flex;gap:10px;margin-top:6px;}
  .btn{
    flex:1;padding:12px 16px;border-radius:10px;border:1px solid var(--line);
    font-family:var(--font-body);font-weight:700;font-size:.95rem;cursor:pointer;
    background:#fff;color:var(--ink);
  }
  .btn--primary{background:var(--brand);color:#fff;border-color:var(--brand);}
  .btn--primary:hover{background:var(--brand-dark);}
  .btn--primary:disabled{opacity:.6;cursor:default;}
  .btn--ghost{background:transparent;}
  .btn--block{width:100%;flex:none;}

  .modal-close{
    position:absolute;top:12px;right:14px;background:none;border:none;
    font-size:1.4rem;color:var(--muted);cursor:pointer;line-height:1;
  }

  /* ---------- Lightbox ---------- */
  .lightbox{
    position:fixed;inset:0;background:rgba(8,14,22,.92);
    display:flex;align-items:center;justify-content:center;z-index:200;
    opacity:0;pointer-events:none;transition:opacity .2s ease;padding:24px;
  }
  .lightbox.is-open{opacity:1;pointer-events:auto;}
  .lightbox img{max-width:100%;max-height:100%;border-radius:6px;}

  /* ---------- Toast ---------- */
  .toast{
    position:fixed;bottom:calc(92px + env(safe-area-inset-bottom));left:50%;
    transform:translate(-50%,12px);background:var(--navy);color:#fff;
    padding:11px 18px;border-radius:999px;font-size:.86rem;
    box-shadow:0 6px 16px rgba(0,0,0,.25);
    opacity:0;pointer-events:none;transition:opacity .25s,transform .25s;
    z-index:300;max-width:88%;text-align:center;
  }
  .toast.is-open{opacity:1;transform:translate(-50%,0);}

  /* ---------- Setup banner ---------- */
  .setup-banner{
    background:var(--amber);color:#2A1B00;font-size:.85rem;
    padding:10px 16px;text-align:center;line-height:1.5;
  }
  .setup-banner code{background:rgba(0,0,0,.08);padding:1px 5px;border-radius:4px;}

  .footer-note{
    padding:18px 16px 48px;font-size:.78rem;color:var(--muted);
    line-height:1.6;border-top:1px solid var(--line);margin-top:8px;
  }