/* ============================================================
   黑牛工具 · Shared Design System  v4
   完整採用 PrimeStride AI 的設計語言：
   · paper #f3f4f6 / ink #0e1116 / line #e3e6eb
   · iris #3d2ce0 / iris-bright #6b5bff / iris-tint #eeebff
   · Bricolage Grotesque（標題）+ IBM Plex Sans（內文）
     + IBM Plex Mono（標籤）+ Noto Sans TC（中文）
   每頁只需要：
     <link rel="stylesheet" href="/assets/base.css">  (或 ../assets/base.css)
   ============================================================ */

:root{
  /* canvas — PrimeStride paper */
  --bg:#F3F4F6;
  --bg-soft:#FAFAFC;
  --surface:#FFFFFF;
  --surface2:#F1F0FA;
  --line:#E3E6EB;
  --line2:#D5D9E0;

  /* ink */
  --ink:#0E1116;
  --ink-soft:#171B24;
  --ink2:#5B6472;
  --muted:#9AA1AF;

  /* brand — iris */
  --hi:#3D2CE0;
  --hi-strong:#2F22B8;
  --hi-bright:#6B5BFF;
  --hi-ink:#FFFFFF;
  --hi-soft:#EEEBFF;
  --fix:#3D2CE0;
  --fix-ink:#FFFFFF;
  --good:#0D8A63;
  --danger:#E8552B;

  /* dark contrast section */
  --dark:#12141D;
  --dark2:#0F1117;
  --dark-card:#181B26;
  --dark-line:rgba(255,255,255,.09);
  --dark-ink:#F2F4F8;
  --dark-ink2:#A7ADBA;
  --dark-acc:#8B7FFF;

  /* shape */
  --r:12px;
  --r-lg:16px;
  --r-md:12px;
  --r-sm:10px;

  /* type — PrimeStride stack */
  --display:"Bricolage Grotesque","Noto Sans TC",sans-serif;
  --cjk:"IBM Plex Sans","Noto Sans TC","PingFang TC","Microsoft JhengHei",system-ui,sans-serif;
  --num:"Bricolage Grotesque","IBM Plex Sans","Noto Sans TC",system-ui,sans-serif;
  --mono:"IBM Plex Mono","SF Mono","JetBrains Mono",ui-monospace,monospace;

  --shadow:0 1px 2px rgba(14,17,22,.04),0 12px 32px rgba(14,17,22,.05);
  --wrap:1080px;
}

*{margin:0;padding:0;box-sizing:border-box;-webkit-tap-highlight-color:transparent;}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;}

body{
  background:var(--bg);
  color:var(--ink);
  font-family:var(--cjk);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  min-height:100vh;
  overflow-x:hidden;
  overflow-wrap:break-word;
}

::selection{background:var(--hi);color:#fff;}
a{color:inherit;}
a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible,select:focus-visible{
  outline:2px solid var(--hi);outline-offset:3px;border-radius:4px;
}
.num{font-family:var(--num);font-variant-numeric:tabular-nums;font-feature-settings:"tnum" 1;}

.wrap{max-width:var(--wrap);margin:0 auto;padding:0 24px;}
.wrap-narrow{max-width:640px;margin:0 auto;padding:0 24px;}

/* ---------------- 導覽列 ---------------- */
.site-nav{
  position:sticky;top:0;z-index:50;
  backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  background:rgba(243,244,246,.82);
  border-bottom:1px solid var(--line);
}
.site-nav .wrap{display:flex;align-items:center;gap:20px;height:64px;}
.brandmark{display:flex;align-items:center;gap:11px;text-decoration:none;flex:none;}
.brandmark svg{width:30px;height:30px;display:block;}
.brandmark .bt{line-height:1.2;}
.brandmark .bt .n{font-size:16.5px;font-weight:900;letter-spacing:.02em;color:var(--ink);}
.brandmark .bt .n b{color:var(--hi);font-weight:900;}
.brandmark .bt .s{font-size:10.5px;color:var(--muted);font-weight:700;letter-spacing:.14em;font-family:var(--mono);}
.nav-links{display:flex;align-items:center;gap:4px;margin-left:auto;}
.nav-links a{
  text-decoration:none;color:var(--ink2);font-size:13.5px;font-weight:600;
  padding:8px 12px;border-radius:999px;transition:color .15s,background .15s;
}
.nav-links a:hover{color:var(--ink);background:rgba(14,17,22,.05);}
.nav-links a.cta{
  background:var(--hi);color:#fff;margin-left:8px;font-weight:600;
  box-shadow:0 6px 18px -6px rgba(61,44,224,.55);
}
.nav-links a.cta:hover{background:var(--hi-bright);color:#fff;}
@media (max-width:640px){
  .nav-links a:not(.cta){display:none;}
}

/* ---------------- 共用文字系統 ---------------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:9px;
  font-family:var(--mono);font-size:11.8px;font-weight:500;
  letter-spacing:.2em;text-transform:uppercase;color:var(--hi);
}
.eyebrow::before{content:"";width:22px;height:2px;background:var(--hi);}

.h-display{
  font-family:var(--display);
  font-size:clamp(2.4rem,4.9vw,4.1rem);
  font-weight:800;line-height:1.12;letter-spacing:-.02em;
}
.h-display .acc{color:var(--hi);}

.h-sec{
  font-family:var(--display);
  font-size:clamp(2rem,4vw,3rem);
  font-weight:800;line-height:1.16;letter-spacing:-.02em;
}

.lede{color:var(--ink2);font-size:1.05rem;max-width:56ch;}
.lede b{color:var(--ink);}

.mono-note{font-family:var(--mono);font-size:12px;color:var(--muted);letter-spacing:.04em;}
.mono-note b{color:var(--hi);font-weight:600;}

/* ---------------- 按鈕 ---------------- */
.btn{
  appearance:none;border:1px solid transparent;cursor:pointer;font-family:inherit;
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  font-weight:600;font-size:.95rem;border-radius:var(--r);padding:.78rem 1.35rem;
  text-decoration:none;transition:transform .18s,background .18s,border-color .18s,color .18s,box-shadow .18s;
}
.btn:active{transform:translateY(0);}
.btn svg{width:16px;height:16px;transition:transform .18s;}
.btn:hover svg{transform:translateX(3px);}
.btn-hi{background:var(--hi);color:#fff;box-shadow:0 6px 18px -6px rgba(61,44,224,.55);}
.btn-hi:hover{background:var(--hi-bright);transform:translateY(-2px);}
.btn-fix{background:var(--hi);color:#fff;box-shadow:0 6px 18px -6px rgba(61,44,224,.55);}
.btn-fix:hover{background:var(--hi-bright);transform:translateY(-2px);}
.btn-ghost{background:transparent;color:var(--ink);border-color:var(--line2);}
.btn-ghost:hover{border-color:var(--hi);color:var(--hi);}

/* ---------------- 卡片 ---------------- */
.card{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  box-shadow:var(--shadow);
}
.tagpill{
  display:inline-block;font-size:11px;font-weight:700;letter-spacing:.05em;
  padding:3px 10px;border-radius:999px;background:var(--hi-soft);color:var(--hi);
}
.tagpill.y{background:var(--ink);color:#fff;}
.tagpill.ghost{background:transparent;color:var(--muted);border:1px solid var(--line2);}

/* ---------------- 頁尾 ---------------- */
.site-foot{border-top:1px solid var(--line);margin-top:96px;}
.site-foot .wrap{
  padding-top:44px;padding-bottom:44px;
  display:flex;flex-wrap:wrap;gap:26px;align-items:flex-start;justify-content:space-between;
}
.site-foot .who{font-weight:800;font-size:15.5px;}
.site-foot .who b{color:var(--hi);}
.site-foot .desc{color:var(--ink2);font-size:13px;margin-top:6px;max-width:46ch;line-height:1.7;}
.site-foot .links{display:flex;gap:8px;flex-wrap:wrap;}
.site-foot .links a{
  color:var(--ink2);text-decoration:none;font-weight:600;font-size:13px;
  border:1px solid var(--line2);border-radius:999px;padding:8px 16px;background:transparent;
  transition:border-color .15s,color .15s;
}
.site-foot .links a:hover{border-color:var(--hi);color:var(--hi);}
.site-foot .fine{
  border-top:1px solid var(--line);padding:18px 24px 26px;
  text-align:center;color:var(--muted);font-size:12px;font-family:var(--mono);letter-spacing:.03em;
}

/* ---------------- 動效（節制） ---------------- */
@keyframes rise{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
.rise{animation:rise .5s cubic-bezier(.2,.7,.2,1) both;}
@media (prefers-reduced-motion: reduce){
  *{animation:none!important;transition:none!important;scroll-behavior:auto!important;}
}