/* bycong.com — 苹果风基线复用自 boyangcong.com,按中文排版调整:
   PingFang 字族提前、正文行高加大、标题不用负字距 */
:root{
  --canvas:#ffffff;
  --alt:#f5f5f7;
  --text:#1d1d1f;
  --text-2:#6e6e73;
  --hairline:#d2d2d7;
  --accent:#0071e3;
  --card:#ffffff;
  --card-shadow:0 4px 24px rgba(0,0,0,.06);
  --nav-bg:rgba(255,255,255,.72);
  --grad-a:#0A84FF;
  --grad-b:#5E5CE6;
  --maxw:980px;
}
@media (prefers-color-scheme:dark){
  :root{
    --canvas:#000000;
    --alt:#1d1d1f;
    --text:#f5f5f7;
    --text-2:#86868b;
    --hairline:#424245;
    --accent:#2997ff;
    --card:#161617;
    --card-shadow:0 4px 24px rgba(0,0,0,.5);
    --nav-bg:rgba(22,22,23,.72);
  }
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"PingFang SC",-apple-system,BlinkMacSystemFont,"Hiragino Sans GB","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  color:var(--text);
  background:var(--canvas);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}

/* ---- animated orbit decoration ---- */
@keyframes orbit{to{transform:rotate(360deg)}}
.orbit-lg{transform-box:view-box;transform-origin:100px 100px;animation:orbit 22s linear infinite}
@media (prefers-reduced-motion:reduce){.orbit-lg{animation:none}}

/* ---- nav ---- */
header.nav{
  position:sticky;top:0;z-index:50;
  backdrop-filter:saturate(180%) blur(20px);
  -webkit-backdrop-filter:saturate(180%) blur(20px);
  background:var(--nav-bg);
  border-bottom:1px solid var(--hairline);
}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:70px}
.brand{display:flex;align-items:center}
.brand img{display:block;height:34px;width:auto}
.nav-links{display:flex;gap:24px;font-size:15px}
.nav-links a{color:var(--text-2)}
.nav-links a:hover{color:var(--text);text-decoration:none}
.nav-links a[aria-current="page"]{color:var(--text)}
@media(max-width:560px){.nav-links{gap:14px;font-size:14px}.brand img{height:28px}}

/* ---- hero ---- */
.hero{padding:104px 0 96px;text-align:center;position:relative;overflow:hidden}
.hero .wrap{position:relative;z-index:1}
.hero-bg{position:absolute;inset:0;z-index:0;pointer-events:none;overflow:hidden}
.blob{position:absolute;border-radius:50%;filter:blur(72px)}
.blob-a{width:420px;height:420px;background:var(--grad-a);opacity:.42;top:-150px;left:-90px}
.blob-b{width:460px;height:460px;background:var(--grad-b);opacity:.38;bottom:-190px;right:-110px}
@media (prefers-color-scheme:dark){.blob-a{opacity:.30}.blob-b{opacity:.28}}
.hero-ring{position:absolute;right:-40px;top:50%;transform:translateY(-50%);width:min(500px,64vw);color:var(--accent);opacity:.13}
@media(max-width:600px){.hero-ring{display:none}}
.eyebrow{font-size:15px;color:var(--text-2);letter-spacing:.06em;margin-bottom:18px}
.hero h1{
  font-size:clamp(34px,6.4vw,60px);
  line-height:1.2;
  font-weight:600;
  letter-spacing:.01em;
  margin-bottom:22px;
}
.grad{
  background:linear-gradient(120deg,var(--grad-a),var(--grad-b));
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
}
.hero p.lede{
  font-size:clamp(17px,2.2vw,21px);
  color:var(--text-2);
  max-width:640px;margin:0 auto;
  line-height:1.9;
}

/* ---- page hero(内页小标题区) ---- */
.page-hero{padding:72px 0 40px;text-align:center}
.page-hero h1{font-size:clamp(28px,4.6vw,44px);font-weight:600;letter-spacing:.01em}
.page-hero p{color:var(--text-2);margin-top:14px;font-size:17px;max-width:640px;margin-left:auto;margin-right:auto}

/* ---- sections ---- */
section{padding:80px 0}
section.alt{background:var(--alt)}
.section-head{text-align:center;margin-bottom:52px}
.section-head h2{font-size:clamp(26px,3.8vw,38px);font-weight:600;letter-spacing:.01em}
.section-head p{color:var(--text-2);margin-top:12px;font-size:17px}

/* ---- pillars ---- */
.pillars{display:grid;grid-template-columns:1fr 1fr;gap:24px}
@media(max-width:720px){.pillars{grid-template-columns:1fr}}
.pillar{
  background:var(--card);border:1px solid var(--hairline);border-radius:18px;
  padding:32px 30px;box-shadow:var(--card-shadow);
}
.pillar h3{font-size:20px;font-weight:600;margin-bottom:14px;display:flex;align-items:center;gap:10px}
.pillar ul{list-style:none;color:var(--text-2);font-size:15.5px}
.pillar li{padding:8px 0;border-bottom:1px solid var(--hairline)}
.pillar li:last-child{border-bottom:0}
.dot{width:9px;height:9px;border-radius:50%;background:linear-gradient(120deg,var(--grad-a),var(--grad-b));display:inline-block;flex:none}

/* ---- products ---- */
.products{display:grid;grid-template-columns:1fr 1fr;gap:24px}
@media(max-width:720px){.products{grid-template-columns:1fr}}
.product{
  position:relative;background:var(--card);border:1px solid var(--hairline);
  border-radius:20px;padding:34px 32px;box-shadow:var(--card-shadow);
  display:flex;flex-direction:column;min-height:220px;
  transition:transform .25s ease,box-shadow .25s ease;
}
.product:hover{transform:translateY(-4px);box-shadow:0 12px 36px rgba(0,0,0,.12)}
.product h3{font-size:23px;font-weight:600}
.product .cat{font-size:13px;color:var(--text-2);margin:4px 0 16px}
.product p{color:var(--text-2);font-size:15.5px;flex:1;line-height:1.9}
.product .cta{margin-top:20px;font-size:15px;font-weight:500}
.badge{
  align-self:flex-start;margin-top:20px;font-size:12.5px;font-weight:600;
  color:var(--accent);border:1px solid var(--accent);border-radius:980px;
  padding:5px 13px;letter-spacing:.04em;
}
/* ---- product media(产品卡片配图) ---- */
.product-media{
  margin:-34px -32px 22px;aspect-ratio:2/1;overflow:hidden;
  border-radius:19px 19px 0 0;background:var(--alt);
  border-bottom:1px solid var(--hairline);
}
.product-media img{width:100%;height:100%;object-fit:cover;display:block}
.media-note{font-size:12px;color:var(--text-2);margin:-14px 0 14px}
.product-head{display:flex;align-items:center;gap:12px}
.product-icon{width:40px;height:40px;border-radius:10px;flex:none;display:block}
.overseas-note{
  margin-top:28px;padding:18px 22px;border:1px solid var(--hairline);border-radius:14px;
  background:var(--alt);color:var(--text-2);font-size:14px;line-height:1.9;
}

/* ---- scope ---- */
.scope{font-size:17px;line-height:2;max-width:760px;margin:0 auto;text-align:center}
.scope-note{text-align:center;color:var(--text-2);font-size:13px;margin-top:22px}

/* ---- CTA banner ---- */
.cta-banner{text-align:center}
.cta-banner p{color:var(--text-2);margin-bottom:26px;font-size:17px}
.btn{
  display:inline-block;background:var(--accent);color:#fff;border-radius:980px;
  padding:12px 30px;font-size:16px;font-weight:500;
}
.btn:hover{text-decoration:none;opacity:.9}

/* ---- prose(条款/说明类正文) ---- */
.prose{max-width:760px;margin:0 auto;padding:56px 0 88px}
.prose h2{font-size:21px;font-weight:600;margin:40px 0 14px}
.prose h2:first-child{margin-top:0}
.prose p{color:var(--text-2);font-size:15.5px;line-height:2;margin-bottom:14px}
.prose ul,.prose ol{color:var(--text-2);font-size:15.5px;line-height:2;padding-left:1.4em;margin-bottom:14px}
.prose li{margin-bottom:6px}
.prose strong{color:var(--text);font-weight:600}
.notice-card{
  background:var(--card);border:1px solid var(--hairline);border-radius:16px;
  padding:26px 28px;box-shadow:var(--card-shadow);margin:22px 0;
}
.notice-card h3{font-size:17px;font-weight:600;margin-bottom:10px}
.notice-card p,.notice-card ul{color:var(--text-2);font-size:14.5px;line-height:1.9}
.notice-card ul{list-style:none;padding-left:0}
.notice-card li{padding:5px 0}
.contact-lines{font-size:17px;line-height:2.2}
.contact-lines strong{font-weight:600}

/* ---- form ---- */
.form-wrap{max-width:640px;margin:0 auto;padding:40px 0 88px}
.field{margin-bottom:22px}
.field label{display:block;font-size:14.5px;font-weight:500;margin-bottom:8px}
.field label .opt{color:var(--text-2);font-weight:400;font-size:13px}
.field input,.field textarea{
  width:100%;font:inherit;font-size:15.5px;color:var(--text);
  background:var(--card);border:1px solid var(--hairline);border-radius:12px;
  padding:12px 14px;outline:none;
}
.field input:focus,.field textarea:focus{border-color:var(--accent)}
.field textarea{min-height:140px;resize:vertical}
.form-hint{font-size:13px;color:var(--text-2);margin-top:6px}
/* honeypot:仅供反滥用,真人不可见不可达 */
.hp-field{position:absolute !important;left:-9999px !important;width:1px;height:1px;overflow:hidden}
.form-actions{margin-top:30px}
.form-msg{margin-top:18px;font-size:15px;display:none}
.form-msg.ok{display:block;color:var(--accent)}
.form-msg.err{display:block;color:#e13e2a}
button.btn{border:0;cursor:pointer;font-family:inherit}
button.btn:disabled{opacity:.5;cursor:default}

/* ---- footer ---- */
footer{background:var(--alt);border-top:1px solid var(--hairline);padding:56px 0;font-size:14px;color:var(--text-2)}
.foot-brand{display:flex;align-items:center;margin-bottom:20px}
.foot-brand img{display:block;height:26px;width:auto}
.foot-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px 40px;max-width:760px}
@media(max-width:560px){.foot-grid{grid-template-columns:1fr}}
.foot-grid dt{color:var(--text);font-weight:500}
.foot-grid dd{color:var(--text-2);margin-top:2px}
.foot-links{margin-top:26px;display:flex;flex-wrap:wrap;gap:8px 22px;font-size:13.5px}
.foot-links a{color:var(--text-2)}
.foot-links a:hover{color:var(--text)}
.beian{margin-top:18px;font-size:13px;display:flex;flex-wrap:wrap;gap:6px 18px;align-items:center}
.beian a{color:var(--text-2)}
.beian img{height:16px;width:auto;vertical-align:-3px;margin-right:4px}
.copyright{margin-top:22px;padding-top:22px;border-top:1px solid var(--hairline);font-size:12.5px}