:root {
  --bg: #0f1115;
  --panel: #171a21;
  --panel-2: #1e222b;
  --border: #2a2f3a;
  --text: #e6e9ef;
  --muted: #9aa3b2;
  --accent: #4f8cff;
  --accent-2: #36c08a;
  --danger: #ff6b6b;
  --radius: 12px;
  --maxw: 960px;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 24px 16px 64px; }
header.site {
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
}
header.site .wrap { display: flex; align-items: center; justify-content: space-between; padding-top: 0; padding-bottom: 0; }
.brand { font-weight: 700; font-size: 18px; letter-spacing: .2px; }
.brand .dot { color: var(--accent); }
.langs { display: flex; gap: 6px; flex-wrap: wrap; }
.langs a {
  font-size: 13px; color: var(--muted);
  border: 1px solid var(--border); border-radius: 999px;
  padding: 3px 10px;
}
.langs a[aria-current="true"] { color: var(--text); border-color: var(--accent); }
h1 { font-size: 30px; margin: 28px 0 6px; }
.subtitle { color: var(--muted); margin: 0 0 22px; }
.tool { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.tool label.field { display: block; font-weight: 600; margin: 14px 0 6px; }
textarea {
  width: 100%; min-height: 200px; resize: vertical;
  background: var(--panel-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px;
  padding: 12px; font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 14px; line-height: 1.5;
}
textarea#output { min-height: 200px; }
.options { display: flex; gap: 18px; flex-wrap: wrap; align-items: center; margin: 12px 0; color: var(--muted); font-size: 14px; }
.options input[type="number"] { width: 56px; background: var(--panel-2); color: var(--text); border: 1px solid var(--border); border-radius: 6px; padding: 4px 6px; }
.buttons { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
button {
  background: var(--panel-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 9px;
  padding: 9px 14px; font-size: 14px; cursor: pointer;
  transition: border-color .15s, background .15s;
}
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
button.primary:hover { filter: brightness(1.08); }
.status { margin: 10px 0 0; min-height: 20px; font-size: 14px; }
.status.ok { color: var(--accent-2); }
.status.err { color: var(--danger); }
.faq { margin-top: 40px; }
.faq h2 { font-size: 22px; margin-bottom: 10px; }
.faq details {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 16px; margin-bottom: 10px;
}
.faq summary { cursor: pointer; font-weight: 600; }
.faq p { color: var(--muted); margin: 8px 0 0; }
footer.site { border-top: 1px solid var(--border); margin-top: 48px; padding: 20px 0; color: var(--muted); font-size: 13px; }

/* breadcrumb */
.crumb { font-size: 13px; color: var(--muted); margin: 6px 0 0; }
.crumb a { color: var(--muted); }
.crumb span { margin: 0 4px; }
.brand a { color: inherit; }
.brand a:hover { text-decoration: none; }

/* prose blocks on sub-pages */
.prose { margin-top: 32px; }
.prose h2 { font-size: 20px; margin: 24px 0 10px; }
.prose .intro { color: var(--muted); }
.prose ol.steps, .prose ul.features { color: var(--muted); padding-left: 20px; margin: 0; }
.prose ol.steps li, .prose ul.features li { margin: 6px 0; }

/* tool grid (related / more tools) */
.related { margin-top: 40px; }
.related h2 { font-size: 22px; margin-bottom: 12px; }
.tool-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px; }
.tool-grid a {
  display: block; background: var(--panel); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 14px; color: var(--text); font-weight: 600;
  transition: border-color .15s;
}
.tool-grid a:hover { border-color: var(--accent); text-decoration: none; }
.tool-grid a span { display: block; font-weight: 400; font-size: 13px; color: var(--muted); margin-top: 4px; }

/* ad slots — reserve space to avoid layout shift (CWV friendly) */
.ad-slot { margin: 24px 0; text-align: center; min-height: 100px; overflow: hidden; }
.ad-slot ins { display: block; }

@media (max-width: 600px) {
  h1 { font-size: 24px; }
  .wrap { padding: 16px 12px 48px; }
  .tool-grid { grid-template-columns: 1fr; }
}