:root {
    --bg:        #0a0c0f;
    --surface:   #111418;
    --surface2:  #191d24;
    --border:    #2a2f3a;
    --glow:      #00e5ff;
    --glow-dim:  rgba(0,229,255,0.12);
    --glow-mid:  rgba(0,229,255,0.35);
    --amber:     #ffb300;
    --amber-dim: rgba(255,179,0,0.15);
    --text:      #d4dde8;
    --text-dim:  #5a6475;
    --text-mid:  #8896aa;
    --danger:    #ff4d6d;
    --success:   #00e5a0;
    --font-mono: 'Share Tech Mono', monospace;
    --font-display: 'Playfair Display', serif;
    --font-body: 'DM Sans', sans-serif;
    --font-retro: 'VT323', monospace;
    --radius:    6px;
  }

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

  html, body {
    height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 15px;
    line-height: 1.6;
    overflow: hidden;
  }

  /* ── SCANLINE OVERLAY ── */
  body::before {
    content: '';
    position: fixed;
    inset: 0;
    background: repeating-linear-gradient(
      0deg,
      transparent,
      transparent 2px,
      rgba(0,0,0,0.08) 2px,
      rgba(0,0,0,0.08) 4px
    );
    pointer-events: none;
    z-index: 9999;
  }

  /* ── LAYOUT ── */
  .app {
    display: grid;
    grid-template-rows: 56px 1fr;
    height: 100vh;
  }

  /* ── TOPBAR ── */
  .topbar {
    display: flex;
    align-items: center;
    padding: 0 24px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    gap: 16px;
    position: relative;
  }
  .topbar::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--glow), transparent);
    opacity: 0.4;
  }

  .logo {
    font-family: var(--font-retro);
    font-size: 26px;
    color: var(--glow);
    letter-spacing: 2px;
    text-shadow: 0 0 20px var(--glow), 0 0 40px rgba(0,229,255,0.3);
    flex-shrink: 0;
  }
  .logo span { color: var(--amber); text-shadow: 0 0 20px var(--amber); }

  .tagline {
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-dim);
    letter-spacing: 1px;
    text-transform: uppercase;
    flex: 1;
  }

  .topbar-actions { display: flex; gap: 8px; align-items: center; }

  /* ── TABS ── */
  .tabs {
    display: flex;
    gap: 2px;
    background: var(--bg);
    padding: 2px;
    border-radius: var(--radius);
  }
  .tab {
    padding: 5px 14px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 1px;
    text-transform: uppercase;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    background: transparent;
    color: var(--text-dim);
  }
  .tab:hover { color: var(--text); background: var(--surface2); }
  .tab.active {
    background: var(--glow-dim);
    color: var(--glow);
    border: 1px solid rgba(0,229,255,0.2);
  }

  /* ── MAIN AREA ── */
  .main {
    display: grid;
    grid-template-columns: 260px 1fr 220px;
    overflow: hidden;
  }

  /* ── SIDEBAR PANELS ── */
  .panel {
    background: var(--surface);
    border-right: 1px solid var(--border);
    padding: 20px 16px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 20px;
  }
  .panel.right { border-right: none; border-left: 1px solid var(--border); }

  .panel-section { display: flex; flex-direction: column; gap: 10px; }
  .panel-label {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--text-dim);
    padding-bottom: 6px;
    border-bottom: 1px solid var(--border);
  }

  /* ── CONTROLS ── */
  .ctrl-row { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }

  .btn {
    padding: 6px 12px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 1px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface2);
    color: var(--text);
    cursor: pointer;
    transition: all 0.15s;
    text-transform: uppercase;
  }
  .btn:hover { border-color: var(--glow); color: var(--glow); box-shadow: 0 0 8px var(--glow-dim); }
  .btn.primary {
    background: var(--glow-dim);
    border-color: var(--glow);
    color: var(--glow);
  }
  .btn.primary:hover { box-shadow: 0 0 16px var(--glow-mid); }
  .btn.danger { border-color: var(--danger); color: var(--danger); }
  .btn.success { border-color: var(--success); color: var(--success); }
  .btn.sm { padding: 4px 8px; font-size: 10px; }
  .btn:disabled { opacity: 0.35; cursor: not-allowed; }

  .btn-icon {
    width: 30px; height: 30px;
    display: flex; align-items: center; justify-content: center;
    font-family: var(--font-mono);
    font-size: 13px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface2);
    color: var(--text-mid);
    cursor: pointer;
    transition: all 0.15s;
  }
  .btn-icon:hover { border-color: var(--glow); color: var(--glow); }
  .btn-icon.active { border-color: var(--amber); color: var(--amber); background: var(--amber-dim); }

  select, input[type=text], input[type=color] {
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    padding: 5px 8px;
    font-family: var(--font-mono);
    font-size: 11px;
    width: 100%;
    transition: border-color 0.15s;
  }
  select:focus, input:focus { outline: none; border-color: var(--glow); }

  input[type=color] { padding: 2px; height: 30px; cursor: pointer; }

  .color-row { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
  .color-item { display: flex; flex-direction: column; gap: 4px; }
  .color-item label { font-family: var(--font-mono); font-size: 10px; color: var(--text-dim); text-transform: uppercase; letter-spacing: 1px; }

  /* ── MODE TOGGLE ── */
  .mode-toggle {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4px;
    background: var(--bg);
    padding: 3px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
  }
  .mode-btn {
    padding: 7px 6px;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    background: transparent;
    color: var(--text-dim);
    text-align: center;
  }
  .mode-btn.active { background: var(--glow-dim); color: var(--glow); }
  .mode-btn.sim.active { background: var(--amber-dim); color: var(--amber); }

  /* ── STYLE BUTTONS ── */
  .style-row { display: flex; gap: 4px; flex-wrap: wrap; }

  /* ── STATUS INDICATORS ── */
  .status-dot {
    width: 8px; height: 8px;
    border-radius: 50%;
    background: var(--text-dim);
    transition: all 0.3s;
    flex-shrink: 0;
  }
  .status-dot.recording { background: var(--danger); box-shadow: 0 0 8px var(--danger); animation: pulse 1s infinite; }
  .status-dot.playing { background: var(--success); box-shadow: 0 0 8px var(--success); animation: pulse 1s infinite; }

  @keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.4; } }

  .status-row {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 1px;
  }

  /* ── STATS ── */
  .stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
  .stat {
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 8px;
    text-align: center;
  }
  .stat-val {
    font-family: var(--font-retro);
    font-size: 22px;
    color: var(--glow);
    line-height: 1;
  }
  .stat-label {
    font-family: var(--font-mono);
    font-size: 9px;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 2px;
  }

  /* ── CANVAS ── */
  .canvas-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 32px 24px;
    overflow-y: auto;
    background: var(--bg);
    position: relative;
  }

  .canvas-wrap.canvas-theme-c64 {
    background: #8080cc;
  }
  .canvas-wrap.canvas-theme-c64::before { display: none; }

  /* subtle grid bg */
  .canvas-wrap::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
      linear-gradient(rgba(0,229,255,0.03) 1px, transparent 1px),
      linear-gradient(90deg, rgba(0,229,255,0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
  }

  /* ── THE LETTER ── */
  .letter {
    width: 100%;
    max-width: 680px;
    min-height: 480px;
    background: #13161c;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 48px 52px;
    position: relative;
    box-shadow: 0 0 60px rgba(0,0,0,0.5), 0 0 1px var(--glow);
    transition: background 0.3s, color 0.3s;
  }

  /* THEMES */
  .letter.theme-c64 {
    background: #3838a8;
    color: #aaaae6;
    font-family: var(--font-retro);
    font-size: 21px;
    line-height: 1.5;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    border: 32px solid #8080cc;
    border-radius: 2px;
    box-shadow: none;
    outline: none;
  }
  .theme-c64 #editor { text-transform: uppercase; caret-color: #aaaae6; }
  .theme-c64 .letter-meta { color: #8080cc; }
  .theme-c64 .cursor-block { background: #aaaae6; width: 12px; }
  .letter.theme-terminal {
    background: #001a00;
    color: #00ff41;
    font-family: var(--font-mono);
    font-size: 15px;
    border-color: #00ff41;
    box-shadow: 0 0 40px rgba(0,255,65,0.1);
  }
  .letter.theme-modern {
    background: #f8f6f1;
    color: #1a1a1a;
    font-family: var(--font-display);
    font-size: 17px;
    border-color: #e0dbd0;
    box-shadow: 0 8px 60px rgba(0,0,0,0.3);
  }

  /* ── EDITOR ── */
  #editor {
    min-height: 360px;
    outline: none;
    caret-color: var(--glow);
    white-space: pre-wrap;
    word-break: break-word;
  }
  .theme-c64 #editor { caret-color: #928dd6; }
  .theme-terminal #editor { caret-color: #00ff41; }
  .theme-modern #editor { caret-color: #1a1a1a; font-family: var(--font-display); }

  /* ── INLINE STYLES ── */
  .fw-headline { font-size: 1.8em; font-weight: 700; line-height: 1.2; display: block; margin-bottom: 8px; }
  .fw-quote {
    display: block;
    margin: 12px 0;
    padding: 10px 16px;
    border-left: 3px solid var(--glow);
    opacity: 0.85;
    font-style: italic;
  }
  .theme-terminal .fw-quote { border-left-color: #00ff41; }
  .theme-modern .fw-quote { border-left-color: #8b7355; font-family: var(--font-display); }
  .fw-code {
    display: inline;
    font-family: var(--font-mono);
    font-size: 0.85em;
    background: rgba(0,229,255,0.08);
    border: 1px solid rgba(0,229,255,0.15);
    border-radius: 3px;
    padding: 1px 5px;
  }
  .theme-modern .fw-code { background: #e8e4db; border-color: #ccc; color: #333; }
  .fw-bold { font-weight: 700; }
  .fw-italic { font-style: italic; }

  /* color cycling */
  @keyframes cycle1 {
    0%   { color: #ff4d6d; }
    25%  { color: #ffb300; }
    50%  { color: #00e5a0; }
    75%  { color: var(--glow); }
    100% { color: #ff4d6d; }
  }
  .fw-cycle { animation: cycle1 2s linear infinite; }

  /* ── CURSOR BLINK ── */
  .cursor-block {
    display: inline-block;
    width: 10px; height: 1.1em;
    background: var(--glow);
    vertical-align: text-bottom;
    animation: blink 0.8s step-end infinite;
    margin-left: 1px;
  }
  .theme-c64 .cursor-block { background: #aaaae6; width: 12px; }
  .theme-terminal .cursor-block { background: #00ff41; }
  .theme-modern .cursor-block { background: #1a1a1a; }
  @keyframes blink { 50% { opacity: 0; } }

  /* ── PLAYBACK DISPLAY ── */
  #playback-output {
    min-height: 360px;
    white-space: pre-wrap;
    word-break: break-word;
    position: relative;
  }

  /* ── SPEED SLIDER ── */
  .slider-wrap { display: flex; flex-direction: column; gap: 6px; }
  .slider-wrap label { font-family: var(--font-mono); font-size: 10px; color: var(--text-dim); text-transform: uppercase; letter-spacing: 1px; }
  input[type=range] {
    -webkit-appearance: none;
    width: 100%;
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    outline: none;
  }
  input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px; height: 14px;
    background: var(--glow);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 6px var(--glow);
  }

  /* ── SIM STYLES ── */
  .sim-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 4px; }
  .sim-btn {
    padding: 6px 4px;
    font-family: var(--font-mono);
    font-size: 9px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface2);
    color: var(--text-dim);
    cursor: pointer;
    transition: all 0.15s;
    text-align: center;
  }
  .sim-btn:hover { border-color: var(--amber); color: var(--amber); }
  .sim-btn.active { border-color: var(--amber); color: var(--amber); background: var(--amber-dim); }

  /* ── PROGRESS BAR ── */
  .progress-wrap {
    width: 100%;
    height: 3px;
    background: var(--border);
    border-radius: 2px;
    margin-top: 16px;
    overflow: hidden;
  }
  .progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--glow), var(--success));
    border-radius: 2px;
    transition: width 0.1s;
    width: 0%;
  }

  /* ── LETTER HEADER ── */
  .letter-meta {
    position: absolute;
    top: 16px; right: 20px;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-dim);
    letter-spacing: 1px;
  }

  /* ── SCROLLBAR ── */
  ::-webkit-scrollbar { width: 6px; }
  ::-webkit-scrollbar-track { background: var(--bg); }
  ::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
  ::-webkit-scrollbar-thumb:hover { background: var(--text-dim); }

  /* ── HIDDEN ── */
  .hidden { display: none !important; }

  /* ── TOAST ── */
  .toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: var(--surface2);
    border: 1px solid var(--glow);
    color: var(--glow);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 1px;
    padding: 10px 20px;
    border-radius: var(--radius);
    box-shadow: 0 0 20px var(--glow-dim);
    opacity: 0;
    transition: all 0.3s;
    z-index: 1000;
    pointer-events: none;
  }
  .toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

  /* ── SHARE MODAL ── */
  .modal-backdrop {
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.75);
    backdrop-filter: blur(4px);
    z-index: 2000;
    display: flex; align-items: center; justify-content: center;
    opacity: 0; pointer-events: none;
    transition: opacity 0.25s;
  }
  .modal-backdrop.show { opacity: 1; pointer-events: all; }
  .modal {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 32px;
    width: 100%; max-width: 460px;
    box-shadow: 0 0 60px rgba(0,0,0,0.6), 0 0 1px var(--glow);
    transform: translateY(16px);
    transition: transform 0.25s;
    position: relative;
  }
  .modal-backdrop.show .modal { transform: translateY(0); }
  .modal-title {
    font-family: var(--font-retro);
    font-size: 28px;
    color: var(--glow);
    text-shadow: 0 0 16px var(--glow);
    margin-bottom: 6px;
  }
  .modal-sub {
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 24px;
  }
  .modal-close {
    position: absolute; top: 16px; right: 16px;
    background: none; border: none;
    color: var(--text-dim); font-size: 18px; cursor: pointer;
    line-height: 1;
  }
  .modal-close:hover { color: var(--text); }
  .share-url-box {
    display: flex; gap: 8px; margin-bottom: 20px;
  }
  .share-url-box input {
    flex: 1;
    background: var(--bg);
    border: 1px solid var(--glow);
    border-radius: var(--radius);
    color: var(--glow);
    padding: 8px 12px;
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: 1px;
  }
  .share-url-box input:focus { outline: none; }
  .modal-section { margin-bottom: 20px; }
  .modal-label {
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
  }
  .modal-row { display: flex; gap: 8px; margin-bottom: 8px; }
  .modal-row input {
    flex: 1;
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    padding: 7px 10px;
    font-family: var(--font-mono);
    font-size: 12px;
    transition: border-color 0.15s;
  }
  .modal-row input:focus { outline: none; border-color: var(--glow); }
  .expiry-row { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
  .saving-indicator {
    display: flex; align-items: center; gap: 10px;
    font-family: var(--font-mono); font-size: 12px; color: var(--glow);
    margin-bottom: 16px;
  }
  @keyframes spin { to { transform: rotate(360deg); } }
  .spinner {
    width: 16px; height: 16px;
    border: 2px solid var(--glow-dim);
    border-top-color: var(--glow);
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
  }