/* ── Design tokens (default: dark, warm teal accent) ─── */
    :root {
      color-scheme: dark;
      --ink:       #e8edf5;
      --paper:     #0f1419;
      --cream:     #151c26;
      --surface:   #1a2330;
      --accent:    #14b8a6;
      --accent2:   #2dd4bf;
      --muted:     #94a3b8;
      --border:    #334155;
      --placeholder: #64748b;
      --warn:      #fb923c;
      --success:   #34d399;
      --qr-bg:     #ffffff;
      --shadow:    rgba(0, 0, 0, 0.35);
      --shadow-strong: rgba(0, 0, 0, 0.5);
      --radius:    8px;
      --font-head: 'Playfair Display', Georgia, serif;
      --font-body: 'DM Mono', 'Courier New', monospace;
    }


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

    html { scroll-behavior: smooth; }

    body {
      background: var(--paper);
      color: var(--ink);
      font-family: var(--font-body);
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 0 1rem 4rem;
      position: relative;
      overflow-x: hidden;
    }

    /* ── Grain overlay ──────────────────────────────────── */
    body::before {
      content: '';
      position: fixed;
      inset: 0;
      background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.04'/%3E%3C/svg%3E");
      pointer-events: none;
      z-index: 100;
      opacity: 0.22;
    }

    /* ── Header ─────────────────────────────────────────── */
    header {
      width: 100%;
      max-width: 900px;
      display: flex;
      align-items: baseline;
      justify-content: space-between;
      padding: 2rem 0 1.2rem;
      border-bottom: 2px solid var(--ink);
      margin-bottom: 0;
    }

    .top-nav {
      display: flex;
      gap: 0.7rem;
      align-items: center;
      margin-left: auto;
      margin-right: 1rem;
    }

    .top-nav a {
      font-size: 0.6rem;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--muted);
      text-decoration: none;
      border: 1px solid var(--border);
      background: var(--surface);
      padding: 0.32rem 0.62rem;
      margin: 0.08rem 0;
      border-radius: 999px;
      box-shadow: 1px 1px 0 rgba(0, 0, 0, 0.2);
      transition: color 0.15s, border-color 0.15s, background 0.15s, transform 0.15s;
    }

    .top-nav a:hover,
    .top-nav a:focus-visible {
      color: var(--ink);
      border-color: var(--accent);
      background: color-mix(in srgb, var(--surface) 65%, var(--accent) 35%);
      transform: translateY(-1px);
      outline: none;
    }

    .logo {
      font-family: var(--font-head);
      font-size: clamp(1.6rem, 5vw, 2.4rem);
      font-weight: 900;
      letter-spacing: -0.02em;
      line-height: 1;
      color: var(--ink);
    }
    .logo span {
      color: var(--accent);
      font-style: italic;
    }

    .tagline {
      font-size: 0.68rem;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--muted);
      font-weight: 300;
    }

    header h2 {
      font-size: 0.75rem;
      font-weight: 500;
      color: var(--muted);
      letter-spacing: 0.06em;
      text-transform: uppercase;
      margin: 0;
      font-family: var(--font-body);
      line-height: 1.2;
    }

    .top-nav a[aria-current="page"] {
      color: var(--ink);
      border-color: var(--accent);
      background: color-mix(in srgb, var(--surface) 65%, var(--accent) 35%);
    }

    /* ── Main card ──────────────────────────────────────── */
    main {
      width: 100%;
      max-width: 900px;
      display: flex;
      flex-direction: column;
      gap: 0;
    }

    /* ── QR display section ─────────────────────────────── */
    .qr-section {
      background: var(--cream);
      border: 2px solid var(--ink);
      border-bottom: none;
      padding: 2.5rem 2rem 2rem;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 1.5rem;
      position: relative;
      overflow: hidden;
      min-height: 340px;
      transition: background 0.3s;
    }

    /* decorative corner marks */
    .qr-section::before,
    .qr-section::after {
      content: '';
      position: absolute;
      width: 24px;
      height: 24px;
      border-color: var(--accent);
      border-style: solid;
    }
    .qr-section::before { top: 12px; left: 12px; border-width: 2px 0 0 2px; }
    .qr-section::after  { top: 12px; right: 12px; border-width: 2px 2px 0 0; }

    .qr-label {
      font-size: 0.62rem;
      letter-spacing: 0.18em;
      text-transform: uppercase;
      color: var(--muted);
      align-self: flex-start;
    }

    /* placeholder state */
    .qr-placeholder {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 1rem;
      padding: 2rem;
      animation: fadeIn 0.4s ease;
    }

    .qr-placeholder-visual {
      background: var(--qr-bg);
      padding: 16px;
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      box-shadow: 4px 4px 0 var(--shadow);
    }

    .qr-placeholder-visual img {
      display: block;
      width: 240px;
      height: auto;
    }

    .qr-placeholder p {
      font-size: 0.75rem;
      color: var(--muted);
      letter-spacing: 0.08em;
      text-align: center;
    }

    /* actual QR code */
    #qr-output {
      display: none;
      flex-direction: column;
      align-items: center;
      gap: 1.2rem;
      animation: popIn 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
    }

    #qr-output.visible { display: flex; }

    #qr-canvas {
      background: var(--qr-bg);
      padding: 16px;
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      box-shadow: 4px 4px 0 var(--shadow);
    }
    #qr-canvas canvas, #qr-canvas img { display: block; }

    .pdf-fields {
      width: 100%;
      max-width: 320px;
      display: flex;
      flex-direction: column;
      gap: 0.45rem;
      align-self: center;
    }
    .pdf-fields label {
      font-size: 0.58rem;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--muted);
    }
    .pdf-fields input {
      font-family: var(--font-body);
      font-size: 0.78rem;
      width: 100%;
      background: var(--paper);
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      padding: 0.45rem 0.55rem;
      color: var(--ink);
      outline: none;
    }
    .pdf-fields input:focus {
      border-color: var(--accent);
      box-shadow: 0 0 0 2px rgba(20, 184, 166, 0.22);
    }

    /* ── Actions bar ────────────────────────────────────── */
    .qr-actions {
      display: flex;
      gap: 0.6rem;
      flex-wrap: wrap;
      justify-content: center;
    }

    .btn {
      font-family: var(--font-body);
      font-size: 0.68rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      padding: 0.45rem 1rem;
      border: 1.5px solid var(--ink);
      background: transparent;
      color: var(--ink);
      cursor: pointer;
      border-radius: var(--radius);
      transition: background 0.15s, color 0.15s, transform 0.1s;
      white-space: nowrap;
    }
    .btn:hover { background: var(--ink); color: var(--surface); }
    .btn:active { transform: scale(0.97); }

    .btn-primary {
      background: var(--accent);
      color: var(--surface);
      border-color: var(--accent);
    }
    .btn-primary:hover { background: var(--accent2); border-color: var(--accent2); color: var(--surface); }

    /* copy success flash */
    .btn.copied {
      background: var(--success);
      border-color: var(--success);
      color: var(--surface);
    }

    /* ── Divider strip ──────────────────────────────────── */
    .divider-strip {
      background: linear-gradient(90deg, var(--accent) 0%, #0d9488 55%, #115e59 100%);
      color: var(--surface);
      font-size: 0.58rem;
      letter-spacing: 0.22em;
      text-transform: uppercase;
      padding: 0.4rem 1.5rem;
      text-align: center;
    }

    /* ── Input section ──────────────────────────────────── */
    .input-section {
      background: var(--surface);
      border: 2px solid var(--ink);
      border-top: none;
      padding: 1.8rem 2rem 2rem;
      display: flex;
      flex-direction: column;
      gap: 1rem;
    }

    .input-header {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
    }

    .input-label {
      font-size: 0.62rem;
      letter-spacing: 0.18em;
      text-transform: uppercase;
      color: var(--muted);
    }

    .char-count {
      font-size: 0.62rem;
      color: var(--muted);
      letter-spacing: 0.05em;
    }
    .char-count.warn { color: var(--warn); }

    .input-status {
      font-size: 0.62rem;
      color: var(--muted);
      letter-spacing: 0.06em;
      line-height: 1.5;
      min-height: 1.5em;
    }
    .input-status.warn { color: var(--warn); }
    .input-status.ok { color: var(--success); }

    .privacy-note {
      font-size: 0.58rem;
      color: var(--muted);
      letter-spacing: 0.04em;
      line-height: 1.45;
      margin-top: 0.25rem;
    }

    details.advanced-options {
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      background: var(--paper);
      padding: 0.65rem 0.85rem;
    }
    details.advanced-options summary {
      font-size: 0.62rem;
      letter-spacing: 0.14em;
      text-transform: uppercase;
      color: var(--ink);
      cursor: pointer;
      list-style: none;
      user-select: none;
    }
    details.advanced-options summary::-webkit-details-marker { display: none; }
    details.advanced-options summary::after {
      content: ' ▾';
      font-size: 0.55rem;
      color: var(--muted);
    }
    details.advanced-options[open] summary::after { content: ' ▴'; }
    .advanced-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
      gap: 0.85rem 1rem;
      margin-top: 0.85rem;
      padding-top: 0.75rem;
      border-top: 1px solid var(--border);
    }
    .advanced-field label {
      display: block;
      font-size: 0.58rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--muted);
      margin-bottom: 0.35rem;
    }
    .advanced-field input[type="color"] {
      width: 100%;
      height: 36px;
      padding: 2px;
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      cursor: pointer;
      background: var(--surface);
    }
    .advanced-field select {
      font-family: var(--font-body);
      font-size: 0.68rem;
      width: 100%;
      background: var(--surface);
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      padding: 0.4rem 0.5rem;
      color: var(--ink);
      cursor: pointer;
    }

    textarea {
      font-family: var(--font-body);
      font-size: 0.95rem;
      color: var(--ink);
      background: var(--paper);
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      padding: 1rem 1.1rem;
      width: 100%;
      resize: vertical;
      min-height: 130px;
      line-height: 1.65;
      outline: none;
      transition: border-color 0.2s, box-shadow 0.2s;
      letter-spacing: 0.01em;
    }
    textarea::placeholder { color: var(--placeholder); }
    textarea:focus {
      border-color: var(--accent);
      box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.28);
    }

    .input-actions {
      display: flex;
      gap: 0.6rem;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }

    .size-selector {
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .size-selector label {
      font-size: 0.62rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--muted);
    }
    .size-selector select {
      font-family: var(--font-body);
      font-size: 0.7rem;
      background: var(--paper);
      border: 1.5px solid var(--border);
      border-radius: var(--radius);
      padding: 0.3rem 0.5rem;
      color: var(--ink);
      cursor: pointer;
      outline: none;
    }
    .size-selector select:focus { border-color: var(--ink); }

    /* ── Popular site cards ───────────────────────────────── */
    .popular-section {
      width: 100%;
      margin-top: 2.5rem;
      padding-top: 1.5rem;
      border-top: 2px solid var(--ink);
    }

    .quick-answer {
      margin-top: 1rem;
      border: 2px solid var(--ink);
      background: var(--cream);
      padding: 1.1rem 1.1rem 1rem;
      display: grid;
      gap: 0.65rem;
    }
    .quick-answer h2 {
      font-family: var(--font-head);
      font-size: clamp(1.05rem, 2.2vw, 1.35rem);
      line-height: 1.2;
    }
    .quick-answer h3 {
      font-size: 0.62rem;
      letter-spacing: 0.14em;
      text-transform: uppercase;
      color: var(--muted);
      margin-bottom: 0.22rem;
    }
    .quick-answer p,
    .quick-answer li {
      font-size: 0.74rem;
      line-height: 1.55;
      color: var(--ink);
    }
    .quick-answer ul,
    .quick-answer ol {
      margin-left: 1.05rem;
      display: grid;
      gap: 0.25rem;
    }

    .popular-heading {
      font-family: var(--font-head);
      font-size: 1.1rem;
      font-weight: 700;
      letter-spacing: -0.02em;
      margin-bottom: 0.35rem;
      color: var(--ink);
    }

    .popular-sub {
      font-size: 0.65rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--muted);
      margin-bottom: 1.25rem;
    }

    .site-cards {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
      gap: 1rem;
    }

    .site-card {
      background: var(--cream);
      border: 1.5px solid var(--ink);
      border-radius: var(--radius);
      padding: 1rem 0.85rem;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 0.65rem;
      box-shadow: 3px 3px 0 var(--shadow);
      transition: transform 0.12s ease, box-shadow 0.12s ease;
    }

    .site-card:hover {
      transform: translateY(-2px);
      box-shadow: 4px 5px 0 var(--shadow-strong);
    }

    .site-card-qr {
      background: var(--qr-bg);
      padding: 8px;
      border: 1px solid var(--border);
      border-radius: var(--radius);
      line-height: 0;
    }

    .site-card-qr canvas,
    .site-card-qr img {
      display: block;
      width: 88px !important;
      height: 88px !important;
    }

    .site-card-title {
      font-size: 0.72rem;
      font-weight: 500;
      letter-spacing: 0.06em;
      text-align: center;
      color: var(--ink);
    }

    .site-card-link {
      font-size: 0.58rem;
      color: var(--accent);
      text-decoration: none;
      text-align: center;
      word-break: break-all;
      line-height: 1.35;
      max-width: 100%;
    }

    .site-card-link:hover { text-decoration: underline; }

    /* ── Footer ─────────────────────────────────────────── */
    footer {
      width: 100%;
      max-width: 900px;
      margin-top: 2rem;
      padding-top: 1rem;
      border-top: 1px solid var(--border);
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 0.5rem;
    }

    footer p {
      font-size: 0.62rem;
      color: var(--muted);
      letter-spacing: 0.08em;
    }

    .footer-nav {
      display: inline-flex;
      align-items: center;
      gap: 0.45rem;
    }

    .footer-nav a {
      color: var(--accent);
      text-decoration: none;
      border-bottom: 1px dashed transparent;
      transition: border-color 0.15s;
    }

    .footer-nav a:hover,
    .footer-nav a:focus-visible {
      border-color: var(--accent);
      outline: none;
    }

    .footer-keywords {
      flex: 1 1 100%;
      margin-top: 0.35rem;
      padding-top: 0.65rem;
      border-top: 1px solid var(--border);
      font-size: 0.58rem;
      line-height: 1.5;
      letter-spacing: 0.04em;
      max-width: 100%;
    }

    /* ── Animations ─────────────────────────────────────── */
    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(6px); }
      to   { opacity: 1; transform: translateY(0); }
    }

    @keyframes popIn {
      from { opacity: 0; transform: scale(0.88); }
      to   { opacity: 1; transform: scale(1); }
    }

    /* ── Responsive ─────────────────────────────────────── */
    @media (max-width: 480px) {
      body {
        padding: 0 0 2.5rem;
      }
      header,
      main,
      footer {
        max-width: none;
      }
      header {
        padding: 1.2rem 1rem 1rem;
        display: grid;
        grid-template-columns: 1fr;
        align-items: start;
        justify-items: start;
        gap: 0.45rem;
      }
      header h2 {
        font-size: 0.75rem;
        font-weight: 500;
        color: var(--muted);
        letter-spacing: 0.06em;
        text-transform: uppercase;
      }
      .top-nav {
        margin: 0;
        width: 100%;
        justify-content: flex-start;
        flex-wrap: wrap;
      }
      .tagline {
        margin-top: 0.2rem;
      }
      .qr-section, .input-section { padding: 1.5rem 1.2rem; }
      .input-actions { flex-direction: column; align-items: flex-start; }
      .popular-section { display: none; }
      .qr-actions {
        gap: 0.75rem;
        flex-direction: column;
        width: 100%;
        max-width: 280px;
      }
      .qr-actions .btn {
        min-height: 44px;
        display: flex;
        align-items: center;
        justify-content: center;
        width: 100%;
        padding: 0.55rem 1rem;
        font-size: 0.65rem;
      }
    }