:root {
  --bg: #f6f7fb;
  --card: #ffffff;
  --ink: #1b1f2c;
  --muted: #6b7280;
  --line: #e5e7eb;
  --accent: #4f46e5;
  --accent-dark: #4338ca;
  --accent-soft: #eef2ff;
  --ok: #059669;
  --radius: 14px;
  --shadow: 0 4px 18px rgba(16, 24, 40, .06);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }

.container { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; gap: 26px; height: 62px; }
.logo { font-weight: 800; font-size: 20px; color: var(--ink); letter-spacing: .3px; }
.logo:hover { text-decoration: none; }
.logo span { color: var(--accent); }
.nav-links { display: flex; gap: 22px; margin-left: auto; }
.nav-links a { color: var(--ink); font-size: 15px; font-weight: 500; }
.nav-links a:hover, .nav-links a.active { color: var(--accent); text-decoration: none; }

/* ---------- hero ---------- */
.hero { padding: 66px 0 40px; text-align: center; }
.hero h1 { font-size: clamp(28px, 4.5vw, 44px); line-height: 1.25; margin: 0 0 16px; }
.hero h1 em { font-style: normal; color: var(--accent); }
.hero p { color: var(--muted); font-size: 17px; max-width: 640px; margin: 0 auto 26px; }
.cta-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-block; border: 0; cursor: pointer;
  background: var(--accent); color: #fff;
  padding: 11px 22px; border-radius: 10px;
  font-size: 15px; font-weight: 600;
  transition: background .15s;
}
.btn:hover { background: var(--accent-dark); text-decoration: none; }
.btn.ghost { background: var(--accent-soft); color: var(--accent); }
.btn.ghost:hover { background: #e0e7ff; }
.btn.small { padding: 8px 14px; font-size: 14px; border-radius: 8px; }
.btn.block { width: 100%; }

/* ---------- sections ---------- */
.section { padding: 38px 0; }
.section h2 { font-size: 26px; margin: 0 0 8px; }
.section .sub { color: var(--muted); margin: 0 0 24px; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 18px; }
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 20px;
  box-shadow: var(--shadow);
  transition: transform .15s, box-shadow .15s;
  display: block; color: var(--ink);
}
a.card:hover { transform: translateY(-3px); box-shadow: 0 10px 26px rgba(16,24,40,.10); text-decoration: none; }
.card .ico { font-size: 26px; }
.card h3 { margin: 10px 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }

.badge {
  display: inline-block; background: var(--accent-soft); color: var(--accent);
  font-size: 12px; font-weight: 600; padding: 2px 10px; border-radius: 999px;
}

/* ---------- features ---------- */
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 18px; }
.feature { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.feature h3 { margin: 0 0 8px; font-size: 17px; }
.feature p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* ---------- tool page ---------- */
.tool-wrap { max-width: 860px; margin: 0 auto; }
.breadcrumb { font-size: 13.5px; color: var(--muted); margin: 22px 0 10px; }
.breadcrumb a { color: var(--muted); }
.tool-wrap h1 { font-size: clamp(24px, 3.4vw, 32px); margin: 0 0 10px; }
.tool-intro { color: var(--muted); margin: 0 0 22px; font-size: 16px; }

.panel {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow);
}
.panel + .panel { margin-top: 16px; }
label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
textarea, input[type="text"], input[type="number"], input[type="url"], select {
  width: 100%; padding: 11px 13px; font-size: 14.5px;
  border: 1px solid var(--line); border-radius: 10px;
  background: #fbfbfe; color: var(--ink);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  outline: none;
}
textarea:focus, input:focus, select:focus { border-color: var(--accent); background: #fff; }
textarea { resize: vertical; min-height: 150px; }
textarea.code-out { background: #0f1117; color: #d7e0ff; }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 12px; }
.hint { font-size: 13.5px; color: var(--muted); margin-top: 10px; }
.hint.err { color: #dc2626; }
.result-box {
  margin-top: 12px; padding: 14px; border-radius: 10px;
  background: var(--accent-soft); color: var(--ink);
  font-size: 15px; word-break: break-all; min-height: 24px;
}
.pill-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.pill {
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 5px 13px; font-size: 13.5px; cursor: pointer; color: var(--ink);
}
.pill:hover { border-color: var(--accent); color: var(--accent); }
.thumb { max-width: 320px; border-radius: 10px; border: 1px solid var(--line); display: block; margin-top: 12px; }
#qr-out { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; margin-top: 14px; }
#qr-out img, #qr-out canvas { border: 1px solid var(--line); border-radius: 10px; background: #fff; padding: 8px; }

/* ---------- content blocks ---------- */
.prose { max-width: 860px; margin: 0 auto; }
.prose h2 { font-size: 22px; margin: 30px 0 10px; }
.prose ul, .prose ol { padding-left: 22px; color: var(--ink); }
.prose li { margin: 6px 0; }
.prose p { color: #374151; }

/* ---------- ad slot ---------- */
.ad-slot {
  max-width: 1080px; margin: 26px auto; min-height: 96px;
  display: flex; align-items: center; justify-content: center;
  border: 1.5px dashed var(--line); border-radius: var(--radius);
  color: #b6bcc9; font-size: 13.5px; background: #fbfbfd;
}

/* ---------- shop ---------- */
.shop-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 18px; }
.product { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow); display: flex; flex-direction: column; }
.product .tag { font-size: 12.5px; color: var(--accent); font-weight: 700; letter-spacing: .5px; }
.product h3 { margin: 8px 0; font-size: 18px; }
.product p { color: var(--muted); font-size: 14.5px; margin: 0 0 14px; flex: 1; }
.price { font-size: 24px; font-weight: 800; color: var(--ink); margin-bottom: 12px; }
.price small { font-size: 13px; color: var(--muted); font-weight: 500; }

/* ---------- faq ---------- */
.faq { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 6px 22px; }
.faq details { border-bottom: 1px solid var(--line); padding: 14px 0; }
.faq details:last-child { border-bottom: 0; }
.faq summary { cursor: pointer; font-weight: 600; font-size: 15.5px; }
.faq p { color: var(--muted); font-size: 14.5px; margin: 10px 0 0; }

/* ---------- footer ---------- */
.site-footer {
  margin-top: 50px; border-top: 1px solid var(--line);
  background: #fff; padding: 34px 0 40px;
  color: var(--muted); font-size: 14px;
}
.footer-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 26px; }
.footer-cols h4 { color: var(--ink); font-size: 14.5px; margin: 0 0 10px; }
.footer-cols ul { list-style: none; padding: 0; margin: 0; }
.footer-cols li { margin: 7px 0; }
.footer-cols a { color: var(--muted); }
.footer-cols a:hover { color: var(--accent); }
.copyright { margin-top: 26px; padding-top: 18px; border-top: 1px solid var(--line); text-align: center; font-size: 13px; }

/* ---------- toast ---------- */
#toast {
  position: fixed; left: 50%; bottom: 34px; transform: translateX(-50%) translateY(20px);
  background: #111827; color: #fff; padding: 10px 20px; border-radius: 999px;
  font-size: 14px; opacity: 0; pointer-events: none; transition: all .25s; z-index: 99;
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (max-width: 720px) {
  .nav-links { gap: 14px; }
  .nav-links a { font-size: 14px; }
  .hero { padding-top: 44px; }
}