/* Shared styles for the public tool pages (/whatsapp, /utm, /qr, /en/…). Dark-first; light via OS or saved lnk_theme. */
  :root{
    color-scheme:dark;
    --bg:#0f1115; --card:#171a21; --card-border:#262b36; --ink:#e6e8ee; --muted:#9aa3b2;
    --accent:#7aa2ff; --accent-2:#3f6fe0; --accent-hover:#2f5fd0; --input-bg:#0d0f14; --inset:#0d0f14;
    --wa:#25d366; --wa-on:#04210f; --chip-bg:#1c2a4a; --chip-ink:#aac2ff; --ok-bg:#0f2a1e; --ok-ink:#a9f0cf; --warn:#ffb454; --danger:#ff6b6b;
  }
  @media (prefers-color-scheme: light){:root:not([data-theme="dark"]){
    color-scheme:light;
    --bg:#f3f5f9; --card:#ffffff; --card-border:#d8dee9; --ink:#171a21; --muted:#5e6878;
    --accent:#2f5fd0; --accent-2:#3b6fe0; --accent-hover:#2f5fd0; --input-bg:#ffffff; --inset:#f3f5f9;
    --wa:#128c4a; --wa-on:#ffffff; --chip-bg:#e6edfc; --chip-ink:#2f5fd0; --ok-bg:#e4f5ec; --ok-ink:#1e6b45; --warn:#8a5a0a; --danger:#d6454a;
  }}
  :root[data-theme="light"]{
    color-scheme:light;
    --bg:#f3f5f9; --card:#ffffff; --card-border:#d8dee9; --ink:#171a21; --muted:#5e6878;
    --accent:#2f5fd0; --accent-2:#3b6fe0; --accent-hover:#2f5fd0; --input-bg:#ffffff; --inset:#f3f5f9;
    --wa:#128c4a; --wa-on:#ffffff; --chip-bg:#e6edfc; --chip-ink:#2f5fd0; --ok-bg:#e4f5ec; --ok-ink:#1e6b45; --warn:#8a5a0a; --danger:#d6454a;
  }
  *{box-sizing:border-box}
  body{margin:0;font-family:system-ui,-apple-system,"PingFang HK","Microsoft JhengHei","Noto Sans TC",sans-serif;background:var(--bg);color:var(--ink);line-height:1.7}
  a{color:var(--accent)}
  .wrap{max-width:880px;margin:0 auto;padding:22px 20px 60px}
  header{display:flex;justify-content:space-between;align-items:center;gap:12px;padding-bottom:16px;border-bottom:1px solid var(--card-border)}
  .logo{font-size:23px;font-weight:800;letter-spacing:-.5px;text-decoration:none;color:var(--ink)}.logo span{color:var(--accent)}
  header nav{display:flex;gap:16px;font-size:14px}
  header nav a{text-decoration:none;color:var(--muted)}header nav a:hover{color:var(--ink)}
  .crumb{font-size:12.5px;color:var(--muted);margin:22px 0 0}
  .crumb a{color:var(--muted)}
  h1{font-size:clamp(28px,4.6vw,40px);line-height:1.25;letter-spacing:-.8px;margin:6px 0 8px;text-wrap:balance}
  .lede{color:var(--muted);font-size:16px;max-width:620px;margin:0}
  .chips{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0 0;padding:0;list-style:none}
  .chips li{font-size:12px;font-weight:600;padding:3px 10px;border-radius:99px;background:var(--chip-bg);color:var(--chip-ink)}
  .tool{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);gap:18px;margin:26px 0 8px;align-items:start}
  .card{background:var(--card);border:1px solid var(--card-border);border-radius:16px;padding:22px}
  label{display:block;font-size:13px;color:var(--muted);margin:0 0 6px}
  .field{margin:0 0 16px}
  input,select,textarea{width:100%;background:var(--input-bg);border:1px solid var(--card-border);color:var(--ink);border-radius:10px;padding:11px 12px;font-size:16px;font-family:inherit;min-height:46px}
  textarea{min-height:96px;resize:vertical;line-height:1.6}
  input:focus,select:focus,textarea:focus{outline:0;border-color:var(--accent)}
  .phone{display:grid;grid-template-columns:132px minmax(0,1fr);gap:8px}
  .hint{font-size:12.5px;color:var(--muted);margin:6px 0 0}
  .hint.warn{color:var(--warn)}
  .count{float:right;font-variant-numeric:tabular-nums}
  .presets{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px}
  .presets button{font:inherit;font-size:12.5px;padding:5px 10px;border-radius:99px;border:1px solid var(--card-border);background:transparent;color:var(--ink);cursor:pointer}
  .presets button:hover{background:var(--inset)}
  .out{display:grid;gap:14px;align-content:start}
  .out h2{font-size:15px;margin:0;color:var(--muted);font-weight:600}
  .link-box{background:var(--inset);border:1px solid var(--card-border);border-radius:10px;padding:12px;font-family:ui-monospace,Menlo,Consolas,monospace;font-size:13.5px;overflow-wrap:anywhere;color:var(--accent);min-height:48px}
  .link-box.empty{color:var(--muted);font-family:inherit}
  .row{display:flex;gap:8px;flex-wrap:wrap}
  .btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;background:var(--accent-2);color:#fff;border:0;border-radius:10px;padding:10px 16px;font-size:14px;font-weight:600;cursor:pointer;min-height:44px;text-decoration:none;font-family:inherit}
  .btn:hover{background:var(--accent-hover)}
  .btn.ghost{background:transparent;border:1px solid var(--card-border);color:var(--ink)}
  .btn.ghost:hover{background:var(--inset)}
  .btn.wa{background:var(--wa);color:var(--wa-on)}
  .btn[aria-disabled="true"],.btn:disabled{opacity:.45;pointer-events:none}
  .qr{display:grid;grid-template-columns:136px minmax(0,1fr);gap:14px;align-items:center}
  .qr-frame{width:136px;height:136px;border-radius:12px;background:#fff;display:grid;place-items:center;border:1px solid var(--card-border)}
  .qr-frame img{width:128px;height:128px;display:block}
  .qr-frame span{font-size:12px;color:#5e6878;text-align:center;padding:10px}
  .qr p{margin:0 0 8px;font-size:13px;color:var(--muted)}
  .upsell{border:1px solid var(--accent);border-radius:14px;padding:16px;background:var(--card)}
  .upsell strong{display:block;font-size:15px;margin-bottom:4px}
  .upsell p{margin:0 0 12px;font-size:13.5px;color:var(--muted)}
  #toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:var(--ink);color:var(--bg);padding:9px 16px;border-radius:99px;font-size:14px;opacity:0;transition:opacity .2s;pointer-events:none}
  #toast.show{opacity:1}
  section.content{margin-top:40px}
  section.content h2{font-size:21px;margin:0 0 10px;letter-spacing:-.3px}
  section.content p,section.content li{font-size:15px}
  section.content p{max-width:68ch}
  .steps{padding-left:22px}
  .steps li{margin:6px 0}
  .uses{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;padding:0;list-style:none}
  .uses li{background:var(--card);border:1px solid var(--card-border);border-radius:12px;padding:14px 16px;font-size:14px}
  .uses b{display:block;margin-bottom:2px}
  .uses span{color:var(--muted)}
  code{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:13px;background:var(--inset);border:1px solid var(--card-border);padding:1px 6px;border-radius:6px;overflow-wrap:anywhere}
  .faq details{border-top:1px solid var(--card-border)}
  .faq details:last-child{border-bottom:1px solid var(--card-border)}
  .faq summary{cursor:pointer;list-style:none;display:flex;justify-content:space-between;gap:12px;padding:14px 0;align-items:center}
  .faq summary::-webkit-details-marker{display:none}
  .faq summary::after{content:"+";color:var(--muted);font-size:20px;line-height:1}
  .faq details[open] summary::after{content:"−"}
  .faq h3{font-size:15px;margin:0;font-weight:600}
  .faq p{margin:0 0 14px;color:var(--muted)}
  .note{font-size:12.5px;color:var(--muted);margin-top:34px}
  footer{margin-top:18px;padding-top:16px;border-top:1px solid var(--card-border);font-size:13px;color:var(--muted);display:flex;gap:10px;flex-wrap:wrap}
  a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
  @media(max-width:720px){
    .tool{grid-template-columns:1fr}
    .uses{grid-template-columns:1fr}
    header nav a.hide-sm{display:none}
  }
  @media(max-width:380px){.phone{grid-template-columns:112px minmax(0,1fr)}.qr{grid-template-columns:1fr}}
  @media(prefers-reduced-motion:reduce){#toast{transition:none}}
.ptable{width:100%;border-collapse:collapse;font-size:14px;margin:6px 0 4px}
.ptable th,.ptable td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--card-border);vertical-align:top}
.ptable th{font-size:12px;color:var(--muted);font-weight:600}
.ptable code{white-space:nowrap}
.tbl-wrap{overflow-x:auto;background:var(--card);border:1px solid var(--card-border);border-radius:12px}
.grid2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
@media(max-width:560px){.grid2{grid-template-columns:1fr}}
.req{color:var(--warn);font-weight:700}
.fix{font:inherit;font-size:12.5px;padding:3px 10px;border-radius:99px;border:1px solid var(--warn);background:transparent;color:var(--warn);cursor:pointer;margin-left:6px}
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin:0 0 16px}
.tabs button{font:inherit;font-size:13.5px;font-weight:600;padding:8px 14px;border-radius:99px;border:1px solid var(--card-border);background:transparent;color:var(--muted);cursor:pointer;min-height:38px}
.tabs button[aria-selected="true"]{background:var(--chip-bg);color:var(--chip-ink);border-color:transparent}
.pane[hidden]{display:none}
.opts{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin-top:6px}
.opts input[type=color]{padding:4px;height:46px;cursor:pointer}
@media(max-width:560px){.opts{grid-template-columns:1fr 1fr}}
.qr-big{display:grid;place-items:center;background:#fff;border-radius:14px;border:1px solid var(--card-border);padding:14px;min-height:240px}
.qr-big canvas{max-width:100%;height:auto;image-rendering:pixelated}
.qr-big span{color:#5e6878;font-size:13px;text-align:center}
.callout{border:1px solid var(--warn);border-radius:14px;padding:14px 16px;background:var(--card)}
.callout strong{display:block;margin-bottom:4px}
.callout p{margin:0 0 10px;font-size:13.5px;color:var(--muted)}
.check{display:flex;align-items:center;gap:8px;font-size:14px;color:var(--ink);margin:4px 0 0}
.check input{width:auto;min-height:0}
.ptable tbody th{font-size:14px;color:var(--ink);font-weight:600}