/* ==========================================================================
   AI Seller Copilot — Marketing site styles
   Plain static CSS. No build step required.
   ========================================================================== */

:root {
  --c-bg: #ffffff;
  --c-bg-soft: #f7f8fc;
  --c-bg-muted: #f1f3fb;
  --c-text: #1e2434;
  --c-text-soft: #4b5366;
  --c-text-mute: #7a8195;
  --c-border: #e6e8f2;
  --c-primary: #4f46e5;
  --c-primary-dk: #4338ca;
  --c-primary-soft: #eef0fe;
  --c-accent: #0ea5a4;
  --c-accent-soft: #e6fbfa;
  --c-warn: #b45309;
  --c-danger: #be123c;
  --c-ok: #047857;
  --shadow-sm: 0 1px 2px rgba(20, 23, 39, .06), 0 1px 3px rgba(20, 23, 39, .04);
  --shadow-md: 0 4px 12px rgba(20, 23, 39, .08), 0 2px 4px rgba(20, 23, 39, .04);
  --shadow-lg: 0 18px 48px rgba(20, 23, 39, .12);
  --radius: 14px;
  --radius-sm: 9px;
  --maxw: 1120px;
  --nav-h: 64px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; display: block; }
a { color: var(--c-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; color: var(--c-text); font-weight: 700; letter-spacing: -.01em; }
h1 { font-size: clamp(2rem, 5vw, 3.1rem); }
h2 { font-size: clamp(1.55rem, 3.2vw, 2.15rem); }
h3 { font-size: 1.25rem; }
p { margin: 0 0 1rem; color: var(--c-text-soft); }
ul, ol { margin: 0 0 1rem; padding-left: 1.25rem; color: var(--c-text-soft); }
li { margin-bottom: .4rem; }
small { color: var(--c-text-mute); }
code, kbd { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; background: var(--c-bg-muted); padding: .12em .4em; border-radius: 5px; font-size: .9em; }
hr { border: 0; border-top: 1px solid var(--c-border); margin: 2rem 0; }

/* ---------- layout ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.section { padding: 64px 0; }
.section.tight { padding: 40px 0; }
.section.soft { background: var(--c-bg-soft); }
.section.muted { background: var(--c-bg-muted); }
.section.dark { background: #0f1326; color: #cdd2e4; }
.section.dark h2, .section.dark h3 { color: #fff; }
.section.dark p, .section.dark li { color: #aab1cc; }
.center { text-align: center; }
.eyebrow { display: inline-block; font-size: .8rem; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--c-primary); background: var(--c-primary-soft); padding: .35em .8em; border-radius: 999px; margin-bottom: 1rem; }
.lead { font-size: 1.15rem; color: var(--c-text-soft); max-width: 60ch; }
.muted { color: var(--c-text-mute) !important; }
.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 880px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }

/* ---------- buttons ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: .5rem; font-weight: 600; font-size: 1rem; padding: .72rem 1.3rem; border-radius: 10px; border: 1px solid transparent; cursor: pointer; transition: transform .08s ease, box-shadow .15s ease, background .15s ease; text-decoration: none; }
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--c-primary); color: #fff; box-shadow: var(--shadow-sm); }
.btn-primary:hover { background: var(--c-primary-dk); color: #fff; }
.btn-ghost { background: #fff; color: var(--c-primary); border-color: var(--c-border); }
.btn-ghost:hover { background: var(--c-primary-soft); border-color: var(--c-primary); }
.btn-white { background: #fff; color: var(--c-primary); }
.btn-white:hover { background: #f3f4fe; }
.btn-lg { padding: .95rem 1.7rem; font-size: 1.05rem; }
.btn-sm { padding: .5rem .9rem; font-size: .9rem; }
.btn[disabled] { opacity: .55; cursor: not-allowed; }
.btn-row { display: flex; flex-wrap: wrap; gap: .8rem; align-items: center; }

/* ---------- header / nav ---------- */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,.85); backdrop-filter: saturate(180%) blur(12px); border-bottom: 1px solid var(--c-border); }
.nav { height: var(--nav-h); display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.brand { display: flex; align-items: center; gap: .55rem; font-weight: 800; color: var(--c-text); font-size: 1.08rem; letter-spacing: -.02em; }
.brand:hover { text-decoration: none; }
.brand .logo { width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center; color: #fff; font-weight: 800; background: linear-gradient(135deg, var(--c-primary), var(--c-accent)); box-shadow: var(--shadow-sm); flex: none; }
.nav-links { display: flex; align-items: center; gap: 1.4rem; }
.nav-links a { color: var(--c-text-soft); font-weight: 500; font-size: .95rem; }
.nav-links a:hover { color: var(--c-primary); text-decoration: none; }
.nav-cta { display: flex; align-items: center; gap: .6rem; }
.nav-toggle { display: none; background: none; border: 1px solid var(--c-border); border-radius: 9px; padding: .4rem .55rem; cursor: pointer; }
@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .nav-links { position: absolute; top: var(--nav-h); left: 0; right: 0; background: #fff; border-bottom: 1px solid var(--c-border); flex-direction: column; align-items: stretch; gap: 0; padding: .4rem 0; display: none; }
  .nav-links.open { display: flex; }
  .nav-links a { padding: .8rem 20px; }
  .nav-cta .btn-ghost { display: none; }
}

/* ---------- hero ---------- */
.hero { position: relative; overflow: hidden; padding: 72px 0 64px; background:
    radial-gradient(1100px 480px at 78% -10%, rgba(79,70,229,.12), transparent 60%),
    radial-gradient(900px 420px at 6% 0%, rgba(14,165,164,.10), transparent 55%),
    var(--c-bg); }
.hero .grid { align-items: center; }
.hero h1 { margin-bottom: .35em; }
.hero .lead { margin-bottom: 1.6rem; }
.hero-eyebrow { margin-bottom: 1.1rem; }
.badges-row { display: flex; flex-wrap: wrap; gap: 1.4rem; margin-top: 1.8rem; color: var(--c-text-mute); font-size: .85rem; }
.badges-row span { display: inline-flex; align-items: center; gap: .4rem; }
.dot { width: 6px; height: 6px; border-radius: 50%; background: var(--c-accent); display: inline-block; }

/* product mock card */
.mock { background: #fff; border: 1px solid var(--c-border); border-radius: var(--radius); box-shadow: var(--shadow-lg); overflow: hidden; }
.mock-bar { display: flex; align-items: center; gap: .35rem; padding: .7rem .9rem; border-bottom: 1px solid var(--c-border); background: var(--c-bg-soft); }
.mock-bar i { width: 11px; height: 11px; border-radius: 50%; background: #d7d9e6; display: inline-block; }
.mock-bar .url { margin-left: .6rem; font-size: .78rem; color: var(--c-text-mute); background: #fff; border: 1px solid var(--c-border); padding: .2rem .6rem; border-radius: 6px; }
.mock-body { padding: 1.1rem; }
.mock-row { display: flex; gap: .8rem; align-items: flex-start; padding: .55rem 0; border-bottom: 1px dashed var(--c-border); }
.mock-row:last-child { border-bottom: 0; }
.mock-row .k { width: 96px; flex: none; font-size: .8rem; color: var(--c-text-mute); }
.mock-row .v { font-size: .9rem; color: var(--c-text); }
.mock-row .v b { color: var(--c-primary); }
.pill { display: inline-block; font-size: .72rem; font-weight: 700; padding: .18rem .55rem; border-radius: 999px; background: var(--c-accent-soft); color: var(--c-accent); }
.pill.warn { background: #fef3c7; color: var(--c-warn); }
.pill.ok { background: #d1fae5; color: var(--c-ok); }

/* ---------- feature cards ---------- */
.card { background: #fff; border: 1px solid var(--c-border); border-radius: var(--radius); padding: 1.5rem; box-shadow: var(--shadow-sm); transition: transform .12s ease, box-shadow .15s ease; }
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.card .ico { width: 44px; height: 44px; border-radius: 11px; display: grid; place-items: center; background: var(--c-primary-soft); color: var(--c-primary); font-size: 1.4rem; margin-bottom: .9rem; }
.card h3 { margin-bottom: .35rem; }
.card p { margin: 0; font-size: .95rem; }
.card ul { margin: .8rem 0 0; font-size: .9rem; }

/* feature detailed list */
.feature-block { display: grid; grid-template-columns: 1fr 1fr; gap: 2.4rem; align-items: center; padding: 2.2rem 0; border-bottom: 1px solid var(--c-border); }
.feature-block:last-child { border-bottom: 0; }
.feature-block .visual { background: var(--c-bg-soft); border: 1px solid var(--c-border); border-radius: var(--radius); padding: 1.4rem; min-height: 220px; }
.feature-block.flip .visual { order: 2; }
@media (max-width: 860px) { .feature-block, .feature-block.flip { grid-template-columns: 1fr; } .feature-block.flip .visual { order: 0; } }
.kvs { list-style: none; padding: 0; margin: .6rem 0 0; }
.kvs li { display: flex; gap: .55rem; align-items: flex-start; margin-bottom: .55rem; color: var(--c-text-soft); }
.kvs li::before { content: "✓"; color: var(--c-accent); font-weight: 800; }

/* ---------- pricing ---------- */
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; align-items: stretch; }
@media (max-width: 860px) { .price-grid { grid-template-columns: 1fr; } }
.price-card { background: #fff; border: 1px solid var(--c-border); border-radius: var(--radius); padding: 1.8rem; box-shadow: var(--shadow-sm); display: flex; flex-direction: column; position: relative; }
.price-card.featured { border: 2px solid var(--c-primary); box-shadow: var(--shadow-lg); }
.price-card .tag { position: absolute; top: -13px; right: 18px; background: var(--c-primary); color: #fff; font-size: .72rem; font-weight: 700; padding: .3rem .7rem; border-radius: 999px; letter-spacing: .04em; }
.price-name { font-weight: 700; font-size: 1.15rem; }
.price-desc { color: var(--c-text-mute); font-size: .9rem; min-height: 2.6em; }
.price-amt { display: flex; align-items: baseline; gap: .25rem; margin: .8rem 0 .2rem; }
.price-amt .cur { font-size: 1.2rem; font-weight: 700; color: var(--c-text); }
.price-amt .num { font-size: 2.6rem; font-weight: 800; color: var(--c-text); line-height: 1; }
.price-amt .per { color: var(--c-text-mute); font-size: .95rem; }
.price-old { color: var(--c-text-mute); text-decoration: line-through; font-size: .9rem; margin-bottom: .4rem; }
.price-feats { list-style: none; padding: 0; margin: 1.2rem 0 0; flex: 1; }
.price-feats li { display: flex; gap: .5rem; align-items: flex-start; margin-bottom: .6rem; font-size: .92rem; color: var(--c-text-soft); }
.price-feats li::before { content: "✓"; color: var(--c-accent); font-weight: 800; }
.price-card .btn { margin-top: 1.2rem; }
.price-note { text-align: center; color: var(--c-text-mute); font-size: .85rem; margin-top: 1.4rem; }

/* ---------- steps ---------- */
.steps { counter-reset: step; display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
@media (max-width: 860px) { .steps { grid-template-columns: 1fr; } }
.step { position: relative; padding: 1.6rem; border: 1px solid var(--c-border); border-radius: var(--radius); background: #fff; }
.step::before { counter-increment: step; content: counter(step); position: absolute; top: -16px; left: 1.4rem; width: 34px; height: 34px; border-radius: 50%; background: var(--c-primary); color: #fff; display: grid; place-items: center; font-weight: 800; box-shadow: var(--shadow-sm); }
.step h3 { margin-top: .2rem; }

/* ---------- stats ---------- */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; text-align: center; }
@media (max-width: 720px) { .stats { grid-template-columns: repeat(2, 1fr); } }
.stat .n { font-size: 2.1rem; font-weight: 800; color: var(--c-primary); }
.stat .l { color: var(--c-text-mute); font-size: .9rem; }

/* ---------- FAQ ---------- */
.faq { max-width: 820px; margin: 0 auto; }
details.faq-item { border: 1px solid var(--c-border); border-radius: var(--radius-sm); background: #fff; margin-bottom: .8rem; box-shadow: var(--shadow-sm); }
details.faq-item > summary { list-style: none; cursor: pointer; padding: 1rem 1.2rem; font-weight: 600; color: var(--c-text); display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
details.faq-item > summary::-webkit-details-marker { display: none; }
details.faq-item > summary::after { content: "+"; font-size: 1.3rem; color: var(--c-primary); flex: none; }
details.faq-item[open] > summary::after { content: "–"; }
details.faq-item .ans { padding: 0 1.2rem 1.1rem; color: var(--c-text-soft); }

/* ---------- legal/prose pages ---------- */
.legal { max-width: 820px; margin: 0 auto; }
.legal h1 { font-size: clamp(1.8rem, 4vw, 2.4rem); }
.legal h2 { margin-top: 2.2rem; font-size: 1.3rem; }
.legal h3 { margin-top: 1.4rem; font-size: 1.05rem; color: var(--c-text); }
.legal p, .legal li { color: var(--c-text-soft); }
.legal .meta { color: var(--c-text-mute); font-size: .9rem; margin-bottom: 2rem; }
.legal .toc { background: var(--c-bg-soft); border: 1px solid var(--c-border); border-radius: var(--radius-sm); padding: 1rem 1.4rem 1rem 2.6rem; margin-bottom: 2rem; }
.legal .toc li { margin-bottom: .3rem; }
.legal table { width: 100%; border-collapse: collapse; margin: 1rem 0; font-size: .92rem; }
.legal th, .legal td { border: 1px solid var(--c-border); padding: .6rem .8rem; text-align: left; }
.legal th { background: var(--c-bg-soft); color: var(--c-text); }
.callout { border-left: 4px solid var(--c-primary); background: var(--c-primary-soft); padding: .9rem 1.1rem; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; margin: 1.2rem 0; }
.callout.warn { border-color: var(--c-warn); background: #fffbeb; }
.callout p { margin: 0; color: var(--c-text); }

/* ---------- contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 2.4rem; align-items: start; }
@media (max-width: 860px) { .contact-grid { grid-template-columns: 1fr; } }
.info-list { list-style: none; padding: 0; }
.info-list li { display: flex; gap: .8rem; align-items: flex-start; padding: .9rem 0; border-bottom: 1px solid var(--c-border); }
.info-list li:last-child { border-bottom: 0; }
.info-list .ico { width: 38px; height: 38px; border-radius: 9px; background: var(--c-primary-soft); color: var(--c-primary); display: grid; place-items: center; flex: none; font-size: 1.05rem; }
.info-list .lbl { font-size: .8rem; color: var(--c-text-mute); text-transform: uppercase; letter-spacing: .08em; }
.info-list .val { font-weight: 600; color: var(--c-text); word-break: break-word; }

/* ---------- CTA band ---------- */
.cta-band { background: linear-gradient(135deg, var(--c-primary), #6d62e6); color: #fff; border-radius: var(--radius); padding: 2.6rem; text-align: center; box-shadow: var(--shadow-lg); }
.cta-band h2 { color: #fff; }
.cta-band p { color: rgba(255,255,255,.85); max-width: 60ch; margin: 0 auto 1.4rem; }
.cta-band .btn-white { color: var(--c-primary); }

/* ---------- footer ---------- */
.site-footer { background: #0f1326; color: #aab1cc; padding: 56px 0 26px; margin-top: 0; }
.site-footer a { color: #cdd2e4; }
.site-footer a:hover { color: #fff; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 2rem; }
@media (max-width: 760px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 460px) { .footer-grid { grid-template-columns: 1fr; } }
.footer-brand { display: flex; align-items: center; gap: .55rem; font-weight: 800; color: #fff; font-size: 1.05rem; margin-bottom: .8rem; }
.footer-brand .logo { width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center; color: #fff; font-weight: 800; background: linear-gradient(135deg, var(--c-primary), var(--c-accent)); }
.site-footer h4 { color: #fff; font-size: .82rem; text-transform: uppercase; letter-spacing: .1em; margin-bottom: .9rem; }
.footer-links { list-style: none; padding: 0; margin: 0; }
.footer-links li { margin-bottom: .55rem; }
.footer-links a { font-size: .92rem; }
.footer-bottom { border-top: 1px solid #252a44; margin-top: 2.4rem; padding-top: 1.2rem; display: flex; justify-content: space-between; flex-wrap: wrap; gap: .6rem; font-size: .85rem; color: #7e85a3; }
.footer-bottom .pay-note { display: flex; align-items: center; gap: .4rem; }

/* utility */
.mt-0 { margin-top: 0; } .mt-1 { margin-top: .5rem; } .mt-2 { margin-top: 1rem; } .mt-3 { margin-top: 1.6rem; }
.mb-0 { margin-bottom: 0; } .mb-2 { margin-bottom: 1rem; } .mb-3 { margin-bottom: 1.6rem; }
.hidden { display: none !important; }
.nowrap { white-space: nowrap; }
.stack > * + * { margin-top: 1rem; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }