:root {
    --bg: #0b1120;
    --bg-grad-1: #0b1120;
    --bg-grad-2: #131c34;
    --card-bg: #161f38;
    --card-bg-2: #1c2745;
    --accent: #38bdf8;
    --accent-2: #a78bfa;
    --accent-3: #f472b6;
    --text: #f8fafc;
    --text-muted: #94a3b8;
    --border: #2a3654;
    --success: #22c55e;
    --danger: #f87171;
  }

  * { box-sizing: border-box; margin: 0; padding: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }

  body {
    background: radial-gradient(ellipse at top, var(--bg-grad-2), var(--bg-grad-1) 60%);
    color: var(--text);
    min-height: 100vh;
    padding: 16px;
    display: flex;
    justify-content: center;
  }

  .container { width: 100%; max-width: 880px; display: flex; flex-direction: column; gap: 18px; }

  /* Hero header */
  header.hero {
    text-align: center;
    padding: 28px 16px 8px;
  }
  .site-logo { margin-bottom: 10px; filter: drop-shadow(0 4px 12px rgba(56,189,248,0.25)); }
  header.hero h1 {
    font-size: 1.9rem;
    font-weight: 800;
    background: linear-gradient(90deg, var(--accent), var(--accent-2) 60%, var(--accent-3));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 6px;
    letter-spacing: -0.5px;
  }
  header.hero p { color: var(--text-muted); font-size: 0.9rem; }

  /* Search */
  .search-wrap { position: relative; }
  .search-wrap input {
    width: 100%;
    padding: 13px 16px 13px 42px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 12px;
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.2s;
  }
  .search-wrap input:focus { border-color: var(--accent); }
  .search-wrap::before {
    content: "🔍";
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 0.9rem;
    opacity: 0.6;
  }

  /* Category pills */
  .cat-pills { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 4px; scrollbar-width: none; }
  .cat-pills::-webkit-scrollbar { display: none; }
  .cat-pill {
    flex: 0 0 auto;
    padding: 8px 16px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text-muted);
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s;
  }
  .cat-pill:hover { border-color: var(--accent); color: var(--text); }
  .cat-pill.active {
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
    color: #0b1120;
    border-color: transparent;
  }

  /* Tool grid */
  #tools-grid-section { display: flex; flex-direction: column; gap: 18px; }
  .cat-group-title {
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 10px;
    padding-left: 2px;
  }
  .tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 10px;
  }
  .tool-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 16px 12px;
    cursor: pointer;
    text-align: center;
    transition: transform 0.15s ease, border-color 0.15s ease, background 0.15s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
  }
  .tool-card:hover { transform: translateY(-3px); border-color: var(--accent); background: var(--card-bg-2); }
  .tool-card .icon-badge {
    width: 42px; height: 42px;
    border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.3rem;
  }
  .tool-card .name { font-size: 0.82rem; font-weight: 600; color: var(--text); line-height: 1.25; }

  .icon-txt { background: rgba(56,189,248,0.15); }
  .icon-img { background: rgba(244,114,182,0.15); }
  .icon-calc { background: rgba(167,139,250,0.15); }
  .icon-dev { background: rgba(34,197,94,0.15); }
  .icon-biz { background: rgba(251,191,36,0.15); }

  .no-results { text-align: center; color: var(--text-muted); padding: 30px 0; font-size: 0.9rem; }

  /* Tool panel */
  #panel-section { display: none; }
  .panel-card { background: var(--card-bg); padding: 20px; border-radius: 16px; border: 1px solid var(--border); box-shadow: 0 8px 24px -8px rgba(0,0,0,0.4); }
  .panel-header { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
  .back-btn {
    background: var(--card-bg-2);
    border: 1px solid var(--border);
    color: var(--text);
    width: 36px; height: 36px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1rem;
    flex-shrink: 0;
  }
  .back-btn:hover { border-color: var(--accent); }
  .panel-title h2 { font-size: 1.1rem; color: var(--accent); }
  .panel-title p { font-size: 0.78rem; color: var(--text-muted); margin-top: 2px; }

  .tool-panel { display: none; }

  .drop-zone {
    border: 2px dashed var(--accent);
    border-radius: 10px;
    padding: 25px 15px;
    text-align: center;
    cursor: pointer;
    background: rgba(56, 189, 248, 0.03);
    margin-bottom: 15px;
    transition: background 0.2s;
  }
  .drop-zone:hover { background: rgba(56, 189, 248, 0.08); }
  .drop-zone p { color: var(--text); font-weight: 500; word-break: break-all; }

  .form-group { margin-bottom: 15px; }
  .form-group label { display: block; margin-bottom: 6px; color: var(--text-muted); font-size: 0.85rem; font-weight: 600; }
  .form-group select, .form-group input, .form-group textarea {
    width: 100%;
    padding: 10px 12px;
    background: #0b1120;
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 8px;
    outline: none;
    font-size: 0.9rem;
  }
  .form-group select:focus, .form-group input:focus, .form-group textarea:focus { border-color: var(--accent); }

  .grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
  .grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }

  .btn {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    font-size: 0.95rem;
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
    color: #0b1120;
    transition: opacity 0.2s;
  }
  .btn:hover { opacity: 0.88; }
  .btn.secondary { background: var(--card-bg-2); color: var(--text); border: 1px solid var(--border); }

  .checkbox-row { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; font-size: 0.85rem; color: var(--text-muted); }
  .checkbox-row input { width: auto; }

  .output-section {
    display: none;
    margin-top: 20px;
    background: #0b1120;
    padding: 15px;
    border-radius: 10px;
    border: 1px solid var(--border);
    text-align: center;
  }
  .preview-img { max-width: 100%; max-height: 250px; border-radius: 8px; margin: 10px 0; border: 1px solid var(--border); }
  .stats-box { display: flex; justify-content: space-around; margin-top: 10px; background: #0b1120; padding: 12px; border-radius: 8px; border: 1px solid var(--border); flex-wrap: wrap; gap: 8px; }
  .result-box { background: #0b1120; border: 1px solid var(--border); border-radius: 10px; padding: 16px; margin-top: 12px; text-align: left; }
  .result-row { display: flex; justify-content: space-between; padding: 6px 0; font-size: 0.88rem; border-bottom: 1px solid var(--border); }
  .result-row:last-child { border-bottom: none; }
  .result-row .val { color: var(--accent); font-weight: 700; }
  .result-big { text-align: center; font-size: 1.8rem; font-weight: 800; color: var(--accent); margin: 8px 0; }
  #qrcode-box img { margin: 10px auto; }
  .color-swatch { width: 100%; height: 80px; border-radius: 10px; border: 1px solid var(--border); margin-bottom: 12px; }

  .error-msg { color: var(--danger); font-size: 0.85rem; margin-top: 8px; display: none; text-align: center; }

  .how-to-use { margin-top: 22px; padding-top: 18px; border-top: 1px solid var(--border); }
  .how-to-use h3 { font-size: 0.95rem; color: var(--text); margin-bottom: 10px; }
  .how-to-use ol { padding-left: 20px; margin-bottom: 10px; }
  .how-to-use li { color: var(--text-muted); font-size: 0.85rem; margin-bottom: 6px; line-height: 1.5; }
  .how-to-use p.about-text { color: var(--text-muted); font-size: 0.85rem; line-height: 1.6; }

  /* Ad slot containers — collapse to nothing until a real ad script fills them */
  .ad-slot { min-height: 0; display: flex; justify-content: center; align-items: center; overflow: hidden; }
  .ad-slot:empty { margin: 0; }
  .ad-slot:not(:empty) { margin: 4px 0 14px; }
  .ad-desktop-only { display: block; }
  .ad-mobile-only { display: none; }
  @media (max-width: 767px) {
    .ad-desktop-only { display: none; }
    .ad-mobile-only { display: block; }
  }

  .site-footer { text-align: center; padding: 20px 10px 8px; color: var(--text-muted); font-size: 0.8rem; }
  .footer-links a { color: var(--text-muted); text-decoration: none; margin: 0 4px; }
  .footer-links a:hover { color: var(--accent); }
  .footer-links span { color: var(--border); }
  .footer-copy { margin-top: 8px; opacity: 0.7; }

  /* Static pages: About / Privacy / Contact */
  .static-page { display: none; max-width: 720px; margin: 0 auto; }
  .static-title {
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
    -webkit-background-clip: text; background-clip: text; color: transparent;
    font-size: 1.6rem; margin: 14px 0 6px;
  }
  .static-updated { color: var(--text-muted); font-size: 0.8rem; margin-bottom: 14px; }
  .static-card { background: var(--card-bg); border: 1px solid var(--border); border-radius: 16px; padding: 22px; line-height: 1.7; color: var(--text-muted); }
  .static-card h2 { color: var(--text); font-size: 1.05rem; margin: 16px 0 8px; }
  .static-card h2:first-child { margin-top: 0; }
  .static-card p, .static-card li { margin-bottom: 10px; }
  .static-card ul { padding-left: 20px; margin-bottom: 12px; }
  .static-card a { color: var(--accent); }
  .success-msg { display: none; background: rgba(34,197,94,0.1); border: 1px solid var(--success); color: var(--success); padding: 12px; border-radius: 8px; margin-top: 12px; font-size: 0.85rem; text-align: center; }
  .direct-contact { margin-top: 14px; color: var(--text-muted); font-size: 0.85rem; text-align: center; }

  @media (max-width: 480px) {
    .grid-2 { grid-template-columns: 1fr; }
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .panel-card { padding: 16px; }
    header.hero h1 { font-size: 1.5rem; }
  }