/* ============================================================
   FeeTrim · 设计系统 (网站28 · OKX 新手省费站)
   清爽双栏资讯站 · 暖白 + 青柠 lime · 省费剪裁母题
   ============================================================ */

/* ---------- 字体自托管 (拉丁标题 Satoshi / mono Commit Mono / 中文标题 阿里妈妈数黑体子集) ---------- */
@font-face{font-family:"Manrope";src:url("../fonts/Manrope-700.woff2") format("woff2");font-weight:700;font-style:normal;font-display:swap}
@font-face{font-family:"Manrope";src:url("../fonts/Manrope-800.woff2") format("woff2");font-weight:800;font-style:normal;font-display:swap}
@font-face{font-family:"Inconsolata";src:url("../fonts/Inconsolata-400.woff2") format("woff2");font-weight:400;font-style:normal;font-display:swap}
@font-face{font-family:"Inconsolata";src:url("../fonts/Inconsolata-700.woff2") format("woff2");font-weight:700;font-style:normal;font-display:swap}

:root{
  /* 配色 · 暖白亮调 + 墨黑 + 青柠 lime (省费点睛) */
  --paper:#f8f6f0; --paper2:#f1eee5; --paper3:#eae6d9;
  --ink:#17181c; --ink2:#5d5f66; --ink3:#8c8e95;
  --line:#e5e1d6; --line2:#d8d3c6;
  --lime:#8fd814; --lime-d:#3f6406; --lime-bg:rgba(143,216,20,.14);
  --card:#fffdf8; --dark:#1a1c20; --dark2:#22242a;
  --danger:#c8402e; --warn:#c98a1e;

  /* 字体 */
  --font-display:"Manrope",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-title:"Manrope",system-ui,-apple-system,"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;
  --font-body:system-ui,-apple-system,"Segoe UI","PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;
  --font-mono:"Inconsolata",ui-monospace,"SF Mono","Cascadia Code",Consolas,monospace;

  /* 字阶 (clamp 模块化) */
  --fs-hero:clamp(1.9rem,1rem+3.4vw,3.1rem);
  --fs-h2:clamp(1.4rem,1rem+1.6vw,2rem);
  --fs-h3:clamp(1.08rem,1rem+.5vw,1.28rem);
  --fs-body:1rem;
  --fs-sm:.88rem;
  --fs-xs:.74rem;

  /* 间距 8pt · 圆角体系 · 阴影 */
  --sp:8px; --r-sm:8px; --r:12px; --r-lg:16px; --r-xl:20px;
  --sh-card:0 1px 2px rgba(23,24,28,.04);
  --sh-pop:0 12px 30px -14px rgba(0,0,0,.2);
  --maxw:1180px;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--font-body);font-size:var(--fs-body);line-height:1.7;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit}
img{max-width:100%;height:auto}
h1,h2,h3,h4{font-family:var(--font-title);font-weight:800;letter-spacing:-.02em;line-height:1.15;text-wrap:balance}
:focus-visible{outline:2px solid var(--lime-d);outline-offset:2px}
.in{max-width:var(--maxw);margin:0 auto;padding:0 clamp(1rem,4vw,2rem)}
.mono{font-family:var(--font-mono)}
.tnum{font-variant-numeric:tabular-nums}

/* ---------- 通用组件 ---------- */
.btn{display:inline-flex;align-items:center;gap:.4rem;font-weight:600;text-decoration:none;border-radius:var(--r-sm);padding:.6rem 1rem;font-size:var(--fs-sm);cursor:pointer;border:1px solid var(--line)}
.btn-primary{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.btn-lime{background:var(--lime);color:#14200a;border-color:var(--lime)}
.btn-ghost{background:var(--card);color:var(--ink)}
.chip{display:inline-block;font-family:var(--font-mono);font-size:var(--fs-xs);font-weight:700;color:var(--lime-d);background:var(--lime-bg);border-radius:5px;padding:.15rem .45rem}
.sec-k{font-family:var(--font-mono);font-size:var(--fs-xs);color:var(--lime-d);font-weight:700;margin:0 0 .45rem}
.sec-t{font-size:var(--fs-h2);margin:0 0 .4rem}
.sec-lead{font-size:var(--fs-sm);color:var(--ink2);margin:0 0 1.3rem;line-height:1.6;max-width:52ch}
.band{border-bottom:1px solid var(--line)}

/* ---------- header · 居中 logo + 居中下拉导航 ---------- */
header.site{border-bottom:1px solid var(--line);background:var(--paper)}
.brand{display:flex;flex-direction:column;align-items:center;gap:.2rem;padding:1.5rem 0 .3rem}
.brand .logo{font-family:var(--font-display);font-weight:900;font-size:1.9rem;letter-spacing:-.02em;display:flex;align-items:center;gap:.5rem;text-decoration:none;color:var(--ink)}
.brand .logo .s{color:var(--lime-d)}
.brand .tag{font-size:var(--fs-xs);color:var(--ink2);letter-spacing:.04em}
nav.main{display:flex;justify-content:center;flex-wrap:wrap;gap:.4rem;padding:.5rem 0 1.1rem}
nav.main .item{position:relative}
nav.main .item>a{display:inline-flex;align-items:center;gap:.28rem;font-size:.9rem;color:var(--ink);text-decoration:none;padding:.55rem .85rem;border-radius:var(--r-sm);font-weight:600;min-height:44px}
nav.main .item>a:hover,nav.main .item>a:focus-visible{background:var(--paper2)}
nav.main .item .ch{font-size:.6rem;color:var(--ink3)}
nav.main .dd{position:absolute;top:100%;left:50%;transform:translateX(-50%);background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:.5rem;min-width:190px;display:none;z-index:20;box-shadow:var(--sh-pop)}
nav.main .item:hover .dd,nav.main .item:focus-within .dd{display:block}
nav.main .dd a{display:block;font-size:var(--fs-sm);color:var(--ink2);text-decoration:none;padding:.55rem .7rem;border-radius:var(--r-sm);min-height:auto}
nav.main .dd a:hover{background:var(--paper2);color:var(--ink)}
@media(max-width:820px){
  .brand .logo{font-size:1.55rem}
  nav.main{gap:.1rem;overflow-x:auto;flex-wrap:nowrap;justify-content:flex-start;scrollbar-width:none}
  nav.main::-webkit-scrollbar{display:none}
  nav.main .item>a{padding:.5rem .6rem;font-size:.84rem;white-space:nowrap}
  nav.main .dd{display:none!important}
}

/* ---------- 双栏 layout ---------- */
.layout{display:grid;grid-template-columns:minmax(0,1fr) 328px;gap:clamp(1.4rem,3vw,2.6rem);padding:clamp(1.6rem,4vw,2.6rem) 0}
@media(max-width:900px){.layout{grid-template-columns:minmax(0,1fr)}}
main{min-width:0}
section.blk{margin-bottom:clamp(2rem,5vw,3rem)}

/* ---------- hero 大封面 (lime 框深色 + 辉光) ---------- */
.cover{position:relative;border:3px solid var(--lime);border-radius:var(--r-lg);overflow:hidden;background:var(--dark);color:#fff;padding:clamp(1.8rem,4vw,3rem) clamp(1.5rem,3vw,2.4rem);margin-bottom:clamp(1.8rem,4vw,2.6rem)}
.cover::before{content:"";position:absolute;inset:0;background:radial-gradient(120% 90% at 85% 15%,rgba(143,216,20,.22),transparent 55%);pointer-events:none}
.cover>*{position:relative}
.cover .eye{font-size:var(--fs-xs);letter-spacing:.06em;color:var(--lime);margin:0 0 .8rem;font-weight:700}
.cover h1{font-size:var(--fs-hero);line-height:1.08;margin:0 0 .7rem;max-width:16ch;color:#fff}
.cover h1 em{font-style:normal;color:var(--lime);display:inline-block}
.cover p{font-size:1rem;line-height:1.65;color:#d7d8dc;margin:0 0 1.3rem;max-width:42ch}
/* ---------- 教程文章卡 (非对称: feat 上下 / 常规 左右) ---------- */
.tcards{display:flex;flex-direction:column;gap:clamp(.9rem,2vw,1.15rem)}
.tcard{display:grid;grid-template-columns:minmax(0,1fr);background:var(--card);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;text-decoration:none;color:var(--ink);transition:border-color .2s,transform .2s}
.tcard:hover{border-color:var(--line2);transform:translateY(-2px)}
.tcard .tb{padding:1rem 1.15rem 1.05rem;min-width:0}
.tcard .cat{font-family:var(--font-mono);font-size:.66rem;font-weight:700;color:var(--lime-d);display:inline-block;margin:0 0 .45rem}
.tcard h3{margin:0 0 .4rem;font-size:var(--fs-h3);line-height:1.3;font-weight:700}
.tcard p{margin:0;font-size:var(--fs-sm);line-height:1.55;color:var(--ink2)}
.tcard .more{display:inline-block;margin-top:.6rem;font-size:.8rem;font-weight:600;color:var(--lime-d)}
.tcard.feat{grid-template-columns:minmax(0,1fr)}
.tcard.feat .tb{padding:1.2rem 1.3rem 1.35rem}
.tcard.feat h3{font-size:1.35rem;margin-bottom:.5rem}
.tcard.feat p{font-size:.92rem}
.th-reg{background:linear-gradient(135deg,#1a1c20,#22301a)}
.th-kyc{background:linear-gradient(135deg,#243244,#2f4a5a)}
.th-buy{background:linear-gradient(135deg,#3a2a18,#7a4a1e)}
.th-fee{background:linear-gradient(135deg,#2c3a10,#5f7d14)}
.th-trap{background:linear-gradient(135deg,#3a1e1c,#7a2f2b)}
.th-safe{background:linear-gradient(135deg,#1c2a24,#245a44)}
/* ---------- 行情热力图 (实时 OKX API) ---------- */
.heatmap-sec .sec-t{margin-bottom:.3rem}
.heatmap{display:grid;grid-template-columns:repeat(auto-fill,minmax(114px,1fr));gap:8px;margin-top:.4rem;min-height:264px}
.hm-cell{border-radius:12px;padding:.7rem .8rem;color:#fff;min-height:80px;display:flex;flex-direction:column;justify-content:space-between;text-shadow:0 1px 2px rgba(0,0,0,.32)}
.hm-cell .sym{font-family:var(--font-display);font-weight:800;font-size:.98rem;letter-spacing:-.01em}
.hm-cell .px{font-family:var(--font-mono);font-size:.7rem;opacity:.88}
.hm-cell .chg{font-family:var(--font-mono);font-weight:700;font-size:.92rem;font-variant-numeric:tabular-nums}
.hm-note{font-size:.72rem;color:var(--ink3);margin:.8rem 0 0}
.hm-loading{grid-column:1/-1;color:var(--ink3);font-size:.85rem;padding:1.2rem 0}
@media(max-width:560px){.heatmap{min-height:456px}}
.home-head{padding:.4rem 0 .2rem;margin-bottom:.2rem}
.home-head h1{font-size:clamp(1.5rem,1rem+2vw,2.2rem);line-height:1.16;margin:0 0 .5rem;letter-spacing:-.02em}
.home-head h1 em{font-style:normal;color:var(--lime-d)}
.home-head p{font-size:.96rem;color:var(--ink2);margin:0;max-width:62ch;line-height:1.6}

/* ---------- 省费算账 (深色) ---------- */
.calc{background:var(--ink);color:var(--paper);border-radius:var(--r-xl);padding:clamp(1.5rem,3vw,2.2rem)}
.calc .sec-k{color:var(--lime)}
.calc .grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:1.4rem;align-items:center}
.calc .lead{font-size:1rem;line-height:1.65;color:#e6e6e9;margin:0 0 .8rem}
.calc .note{font-size:.74rem;color:#9a9ba1;line-height:1.55;margin:.3rem 0 0}
.ledger{font-family:var(--font-mono);font-size:.86rem}
.ledger .lr{display:flex;justify-content:space-between;padding:.5rem 0;border-bottom:1px solid #2c2d31;color:#c9cace;font-variant-numeric:tabular-nums}
.ledger .lr b{color:#fff}
.ledger .lr.tot{border-bottom:none;padding-top:.8rem}
.ledger .lr.tot .big{color:var(--lime);font-size:1.5rem;font-weight:800}
@media(max-width:520px){.calc .grid{grid-template-columns:minmax(0,1fr)}}

/* ---------- 右侧栏 ---------- */
aside{display:flex;flex-direction:column;gap:1.2rem}
@media(min-width:901px){aside{position:sticky;top:1rem;align-self:start}}
.swrap{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:1.1rem 1.15rem}
.side-h{font-size:var(--fs-xs);color:var(--ink2);font-weight:700;letter-spacing:.04em;margin:0 0 .8rem;text-transform:uppercase}
.side-list{list-style:none;margin:0;padding:0}
.side-list li{border-top:1px solid var(--line)}
.side-list li:first-child{border-top:none}
.side-list li a{display:block;padding:.6rem 0;font-size:var(--fs-sm);color:var(--ink);text-decoration:none;min-height:44px}
.side-tool a{display:flex;align-items:center;justify-content:space-between;padding:.6rem 0;border-top:1px solid var(--line);font-size:var(--fs-sm);text-decoration:none;color:var(--ink);min-height:44px}
.side-tool a:first-of-type{border-top:none}
.side-tool .arrow{color:var(--lime-d)}

/* ---------- 文章页 (prose) ---------- */
.crumb{font-size:var(--fs-xs);color:var(--ink3);padding:.4rem 0 0}
.crumb a{color:var(--ink2);text-decoration:none}
.article-head{margin:.5rem 0 1.5rem}
.article-head h1{font-size:clamp(1.7rem,1rem+2.6vw,2.6rem);line-height:1.12;margin:.4rem 0 .7rem}
.article-meta{font-size:var(--fs-xs);color:var(--ink3);font-family:var(--font-mono);display:flex;gap:1rem;flex-wrap:wrap}
.prose{font-size:1.02rem;line-height:1.8;color:#26272c;max-width:70ch}
.prose>*+*{margin-top:1.1rem}
.prose h2{font-size:var(--fs-h2);margin:2rem 0 .2rem;padding-left:.7rem;border-left:4px solid var(--lime)}
.prose h3{font-size:var(--fs-h3);margin:1.6rem 0 .2rem}
.prose a{color:var(--lime-d);text-decoration:underline;text-underline-offset:2px}
.prose ul,.prose ol{padding-left:1.3rem}
.prose li{margin:.4rem 0}
.prose img{border-radius:var(--r);border:1px solid var(--line)}
.prose table{width:100%;border-collapse:collapse;font-size:var(--fs-sm)}
.prose .table-wrap{overflow-x:auto}
.prose th,.prose td{border:1px solid var(--line);padding:.6rem .7rem;text-align:left}
.prose th{background:var(--paper2);font-weight:700}
.prose blockquote{border-left:3px solid var(--line2);padding-left:1rem;color:var(--ink2);margin-left:0}
.callout-tip{background:var(--lime-bg);border:1px solid var(--lime);border-radius:var(--r);padding:1rem 1.15rem;font-size:var(--fs-sm)}
.callout-warn{background:#fbf1e6;border:1px solid #e7c48a;border-radius:var(--r);padding:1rem 1.15rem;font-size:var(--fs-sm)}
.toc{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:1rem 1.2rem;font-size:var(--fs-sm)}
.toc ol{margin:.3rem 0 0;padding-left:1.2rem}
.toc a{color:var(--ink2);text-decoration:none}
/* 文章内 affiliate CTA 条 */
.aff-cta{background:var(--dark);color:#fff;border-radius:var(--r);padding:1.1rem 1.3rem;display:flex;flex-wrap:wrap;gap:.8rem;align-items:center;justify-content:space-between}
.aff-cta .t{font-weight:700}
.aff-cta .code{font-family:var(--font-mono);color:var(--lime);font-weight:700}
.aff-cta .reg{background:var(--lime);color:#14200a;border-radius:var(--r-sm);padding:.6rem 1rem;font-weight:700;text-decoration:none;min-height:44px;display:inline-flex;align-items:center}
.aff-note{font-size:var(--fs-xs);color:var(--ink3);margin-top:.5rem}
/* FAQ */
.faq details{border-top:1px solid var(--line);padding:.3rem 0}
.faq summary{cursor:pointer;font-weight:700;padding:.7rem 0;list-style:none;font-size:var(--fs-sm);min-height:44px;display:flex;align-items:center;justify-content:space-between}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--lime-d);font-family:var(--font-mono)}
.faq details[open] summary::after{content:"−"}
.faq .fa{padding:0 0 .9rem;color:var(--ink2);font-size:var(--fs-sm);line-height:1.7}

/* ---------- 工具页 ---------- */
.tool-panel{background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);padding:clamp(1.2rem,3vw,1.8rem)}
.tool-panel label{display:block;font-size:var(--fs-sm);font-weight:600;margin:.9rem 0 .35rem}
.tool-panel input,.tool-panel select{width:100%;padding:.65rem .8rem;font-size:1rem;border:1px solid var(--line2);border-radius:var(--r-sm);background:var(--paper);font-family:var(--font-body);min-height:44px}
.tool-panel input:focus,.tool-panel select:focus{outline:2px solid var(--lime-d);outline-offset:1px}
.tool-out{margin-top:1.2rem;background:var(--dark);color:#fff;border-radius:var(--r);padding:1.2rem 1.3rem}
.tool-out .big{font-family:var(--font-mono);font-size:1.8rem;font-weight:800;color:var(--lime);font-variant-numeric:tabular-nums}
.tool-out .row{display:flex;justify-content:space-between;font-size:var(--fs-sm);padding:.35rem 0;color:#c9cace;font-family:var(--font-mono);font-variant-numeric:tabular-nums}

/* ---------- footer ---------- */
footer{background:var(--paper2);border-top:1px solid var(--line);padding:2.6rem 0;font-size:.82rem;color:var(--ink2);margin-top:1rem}
.fdisc{max-width:64ch;line-height:1.7;margin:0 0 1.3rem}
.fdisc b{color:var(--ink)}
.fgrid{display:flex;flex-wrap:wrap;gap:2rem}
.fgrid div b{display:block;color:var(--ink);font-size:var(--fs-xs);margin-bottom:.5rem;font-weight:700}
.fgrid a{display:block;color:var(--ink2);text-decoration:none;padding:.18rem 0}
.fgrid a:hover{color:var(--ink)}
.copyright{margin-top:1.5rem;padding-top:1.2rem;border-top:1px solid var(--line);font-size:var(--fs-xs);color:var(--ink3)}

@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}