:root{--brand:#ff6900;--brand-dark:#d95600;--brand-soft:#fff3e8;--text:#212529;--muted:#5f6670;--line:#ebebeb;--bg:#f8f9fa;--radius:12px}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",Roboto,"Helvetica Neue",Arial,sans-serif;color:var(--text);background:#fff;line-height:1.8;font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:var(--brand-dark);text-decoration:none}
a:hover{text-decoration:underline}
.ft-wrap{max-width:1080px;margin:0 auto;padding:0 20px}
.ft-skip{position:absolute;left:-9999px;top:0;background:var(--brand);color:#fff;padding:8px 16px;z-index:100}
.ft-skip:focus{left:0}
/* header */
.ft-site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.96);border-bottom:1px solid var(--line);backdrop-filter:saturate(180%) blur(8px)}
.ft-header-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.ft-logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:18px;color:var(--text)}
.ft-logo:hover{text-decoration:none}
.ft-logo-mark{flex:none}
.ft-logo-text{display:flex;flex-direction:column;line-height:1.2}
.ft-logo-name{font-size:18px;font-weight:700}
.ft-logo-tag{font-size:12px;font-weight:400;color:var(--muted);letter-spacing:.5px;margin-top:2px}
.ft-site-nav ul{list-style:none;margin:0;padding:0;display:flex;gap:4px}
.ft-site-nav a{display:block;padding:8px 12px;border-radius:8px;color:var(--text);font-size:15px}
.ft-site-nav a:hover{background:var(--brand-soft);color:var(--brand-dark);text-decoration:none}
.ft-site-nav a[aria-current=page]{color:var(--brand-dark);font-weight:600}
.ft-nav-toggle{position:absolute;opacity:0;pointer-events:none}
.ft-nav-btn{display:none;cursor:pointer;padding:10px}
.ft-nav-btn span{display:block;width:22px;height:2px;background:var(--text);margin:4px 0;border-radius:2px}
/* hero */
.ft-hero{background:linear-gradient(180deg,var(--brand-soft) 0%,#fff 100%);padding:28px 0 32px}
.ft-hero-home{padding:48px 0 40px}
.ft-hero h1{font-size:34px;line-height:1.35;margin:8px 0 8px;letter-spacing:.5px}
.ft-hero-home h1{font-size:40px}
.ft-lead{font-size:17px;color:#343a40;max-width:860px;margin:12px 0 0}
.ft-meta{color:var(--muted);font-size:14px;margin:0;display:flex;flex-wrap:wrap;gap:4px 16px}
.ft-hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:22px}
.ft-btn{display:inline-block;white-space:nowrap;cursor:pointer;background:var(--brand);color:#fff;padding:12px 26px;border-radius:999px;font-weight:600;font-size:16px;border:2px solid var(--brand);transition:background .2s}
.ft-btn:hover{background:var(--brand-dark);border-color:var(--brand-dark);text-decoration:none}
.ft-btn-ghost{background:#fff;color:var(--brand-dark)}
.ft-btn-ghost:hover{background:var(--brand-soft);color:var(--brand-dark)}
.ft-breadcrumb ol{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;font-size:14px;color:var(--muted)}
.ft-breadcrumb li+li::before{content:"/";margin:0 8px;color:#adb5bd}
.ft-breadcrumb a{color:var(--muted)}
/* banner (home) */
.ft-banner{position:relative;overflow:hidden;padding:56px 0 48px}
.ft-banner-inner{display:grid;gap:36px;align-items:center}
.ft-banner h1{font-size:46px;line-height:1.25;margin:0 0 12px;letter-spacing:.5px}
.ft-banner .ft-lead{font-size:18px}
.ft-banner-art img{width:100%;height:auto}
.ft-banner-chips{list-style:none;padding:0;margin:24px 0 0;display:flex;flex-wrap:wrap;gap:10px}
.ft-banner-chips a{display:inline-block;padding:7px 18px;border-radius:999px;background:#fff;border:1px solid var(--line);color:var(--text);font-size:14px}
.ft-banner-chips a:hover{border-color:var(--brand);color:var(--brand-dark);text-decoration:none}
.ft-side-toc .ft-toc{border:0;padding:0}
/* 结构选项用到的通用样式 */
.ft-strip{padding:22px 0;border-bottom:1px solid var(--line)}
.ft-strip .ft-cards{margin:0}
.ft-hero-grid{display:grid;grid-template-columns:1.15fr 1fr;gap:36px;align-items:center}
.ft-hero-pic{margin:0}
.ft-hero-pic img{border-radius:var(--radius)}
.ft-layout-side{display:grid;grid-template-columns:minmax(0,1fr) 250px;gap:48px;max-width:1180px}
.ft-layout-side.ft-side-left{grid-template-columns:230px minmax(0,1fr)}
.ft-layout-side .ft-content{max-width:none}
.ft-side-toc{position:sticky;top:84px;align-self:start;margin-top:8px;font-size:14px;max-height:calc(100vh - 110px);overflow:auto}
.ft-side-toc .ft-toc ol{columns:1;list-style:none;padding:0;margin:0}
.ft-side-toc .ft-toc li{margin:0 0 8px}
/* content */
.ft-layout{padding:24px 20px 56px}
.ft-content{max-width:860px}
.ft-content h2{font-size:26px;line-height:1.4;margin:44px 0 14px;padding-left:12px;border-left:4px solid var(--brand)}
.ft-content h3{font-size:19px;margin:26px 0 8px}
.ft-content p{margin:0 0 14px}
.ft-content ul,.ft-content ol{padding-left:24px;margin:0 0 16px}
.ft-content li{margin:6px 0}
.ft-summary{background:var(--bg);border:1px solid var(--line);border-radius:var(--radius);padding:18px 22px;margin:8px 0 24px}
.ft-summary-title,.ft-toc-title{font-weight:700;margin:0 0 6px}
.ft-summary ul{margin:0}
.ft-hero-figure{margin:0 0 24px}
.ft-hero-figure img{border-radius:var(--radius);border:1px solid var(--line)}
.ft-hero-figure figcaption{font-size:13px;color:var(--muted);text-align:center;margin-top:8px}
.ft-toc{border:1px solid var(--line);border-radius:var(--radius);padding:16px 22px;margin:0 0 8px}
.ft-toc ol{margin:0;columns:2;column-gap:32px}
.ft-toc li{break-inside:avoid;font-size:15px}
.ft-steps{counter-reset:s;list-style:none;padding-left:0}
.ft-steps>li{counter-increment:s;position:relative;padding-left:42px;margin:12px 0}
.ft-steps>li::before{content:counter(s);position:absolute;left:0;top:2px;width:28px;height:28px;border-radius:50%;background:var(--brand);color:#fff;font-weight:700;font-size:14px;display:flex;align-items:center;justify-content:center}
.ft-table-wrap{overflow-x:auto;margin:0 0 16px;border:1px solid var(--line);border-radius:var(--radius)}
table{width:100%;border-collapse:collapse;font-size:15px;min-width:560px}
caption{text-align:left;font-weight:600;padding:12px 16px;color:var(--muted);font-size:14px}
th,td{padding:12px 16px;border-top:1px solid var(--line);text-align:left;vertical-align:top}
thead th{background:var(--bg);font-weight:600}
.ft-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:0 0 16px}
.ft-card{display:block;border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;color:var(--text);transition:border-color .2s,box-shadow .2s}
.ft-card:hover{border-color:var(--brand);box-shadow:0 4px 14px rgba(255,105,51,.12);text-decoration:none}
.ft-card strong{display:block;font-size:17px;color:var(--brand-dark)}
.ft-card span{font-size:14px;color:var(--muted)}
.ft-note{font-size:14px;color:var(--muted)}
pre{background:#1f2328;color:#f0f3f6;padding:14px 16px;border-radius:10px;overflow-x:auto;font-size:14px;line-height:1.6;margin:8px 0 14px}
code{font-family:Consolas,"SFMono-Regular",Menlo,monospace}
.ft-faq-item{border-bottom:1px solid var(--line);padding:6px 0 4px}
.ft-faq-item h3{margin:14px 0 6px;font-size:18px}
.ft-related{margin-top:48px;background:var(--bg);border-radius:var(--radius);padding:20px 24px}
.ft-related h2{border:0;padding:0;margin:0 0 8px;font-size:20px}
.ft-related ul{margin:0}
/* footer */
.ft-site-footer{background:#1f2328;color:#c9d1d9;padding:40px 0 24px;font-size:14px}
.ft-site-footer a{color:#c9d1d9}
.ft-site-footer a:hover{color:#fff}
.ft-footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:28px}
.ft-footer-logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:16px;color:#fff;margin:0 0 8px}
.ft-footer-title{color:#fff;font-weight:600;margin:0 0 8px}
.ft-site-footer ul{list-style:none;margin:0;padding:0}
.ft-site-footer li{margin:4px 0}
.ft-footer-note{border-top:1px solid #30363d;margin-top:28px;padding-top:16px;color:#8b949e;font-size:13px}
.ft-footer-note p{margin:0 0 6px}
/* responsive */
@media (max-width:960px){
.ft-hero-grid{grid-template-columns:1fr}
.ft-layout-side,.ft-layout-side.ft-side-left{grid-template-columns:minmax(0,1fr);gap:0}
.ft-side-toc{display:none}
.ft-nav-btn{display:block}
.ft-site-nav{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 8px 16px rgba(0,0,0,.06)}
.ft-site-nav ul{flex-direction:column;padding:8px 12px}
.ft-nav-toggle:checked~.ft-site-nav{display:block}
}
@media (max-width:640px){
.ft-banner h1{font-size:30px}
.ft-banner .ft-lead{font-size:16px}
.ft-banner{padding:36px 0 28px}
.ft-hero h1,.ft-hero-home h1{font-size:26px}
.ft-lead{font-size:16px}
.ft-content h2{font-size:22px}
.ft-toc ol{columns:1}
.ft-cards{grid-template-columns:1fr 1fr}
.ft-footer-grid{grid-template-columns:1fr 1fr}
.ft-footer-about{grid-column:1/-1}
}

/* 骨架 ticker：白色页头 + 深灰实心“标签页”导航、深炭灰行情网格横幅（左文右图、底部橙色细线）、
   子页深色条带首屏、顶边加粗的紧凑行情卡片、深色标题栏编号目录、短橙线下划 H2、
   数据感细线表格（深色顶线、斑马纹）、方块编号步骤、Q 标问答、深灰四栏页脚 */
:root{--ink:#22252b;--ink-2:#2d3038;--line:#e3e5e9;--muted:#626873;--bg:#f6f7f9;--radius:3px}
body{color:#1f2228;font-size:15.5px;line-height:1.78}
a{color:var(--brand-dark)}
/* 页头：白底，导航为贴底的方角标签，当前页实心深灰 */
.ft-site-header{background:#fff;border-bottom:1px solid var(--line);backdrop-filter:none}
.ft-header-inner{height:58px}
.ft-logo-name{font-size:17px;letter-spacing:.2px}
.ft-logo-tag{font-size:12px;color:#7a808a}
.ft-site-nav ul{gap:0;height:58px;align-items:stretch}
.ft-site-nav li{display:flex}
.ft-site-nav a{display:flex;flex:1;align-items:center;border-radius:0;padding:0 14px;font-size:14.5px;color:#3a3e46;border-bottom:2px solid transparent}
.ft-site-nav a:hover{background:var(--bg);color:var(--ink);text-decoration:none}
.ft-site-nav a[aria-current=page]{background:var(--ink);color:#fff;font-weight:600;border-bottom-color:var(--brand)}
.ft-nav-btn span{background:var(--ink)}
/* 按钮：小方角，橙色实心；次按钮为深色描边 */
.ft-btn{border-radius:var(--radius);padding:11px 24px;font-size:15px;font-weight:600;letter-spacing:.3px;border-width:1px}
.ft-btn-ghost{background:#fff;color:var(--ink);border-color:#c9ccd2}
.ft-btn-ghost:hover{background:var(--bg);color:var(--ink);border-color:var(--ink)}
/* 首页横幅：深炭灰底 + 行情网格线，左文右图，底边橙线 */
.ft-banner{background-color:#1b1e24;background-image:linear-gradient(rgba(255,255,255,.045) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.045) 1px,transparent 1px),linear-gradient(180deg,#1b1e24 0%,#23272e 100%);background-size:44px 44px,44px 44px,100% 100%;color:#fff;padding:60px 0 52px;border-bottom:4px solid var(--brand)}
.ft-banner-inner{grid-template-columns:minmax(0,1.08fr) minmax(0,.92fr);gap:40px}
.ft-banner h1{font-size:46px;font-weight:700;letter-spacing:0;line-height:1.2;margin-bottom:14px}
.ft-banner h1::before{content:"";display:block;width:56px;height:4px;background:var(--brand);margin-bottom:18px}
.ft-banner .ft-meta{color:#9aa0aa}
.ft-banner .ft-lead{color:#cfd3da;font-size:17px}
.ft-banner .ft-lead strong{color:#fff}
.ft-banner .ft-btn-ghost,.ft-hero .ft-btn-ghost{background:transparent;color:#fff;border-color:rgba(255,255,255,.4)}
.ft-banner .ft-btn-ghost:hover,.ft-hero .ft-btn-ghost:hover{background:rgba(255,255,255,.08);border-color:#fff}
.ft-banner-art{padding:8px;background:rgba(255,255,255,.03);border:1px solid rgba(255,255,255,.08)}
/* 子页首屏：深色条带，右侧配图带细框 */
.ft-hero{background:#23262d;color:#fff;padding:30px 0 34px;border-bottom:3px solid var(--brand)}
.ft-hero h1{font-size:32px;font-weight:700;line-height:1.3;margin:10px 0 8px}
.ft-hero .ft-lead{color:#cdd1d8;font-size:16px}
.ft-hero .ft-lead a,.ft-banner .ft-lead a{color:#ffb27a}
.ft-hero .ft-meta{color:#9aa0aa}
.ft-hero .ft-breadcrumb ol,.ft-hero .ft-breadcrumb a{color:#a5abb4}
.ft-hero .ft-breadcrumb li+li::before{color:#5c616b}
.ft-hero-pic img{border-radius:2px;border:1px solid rgba(255,255,255,.12)}
/* 正文布局 */
.ft-layout{padding:30px 20px 60px}
@media (min-width:961px){.ft-layout-side{grid-template-columns:minmax(0,1fr) 240px;gap:44px}}
.ft-content h2{font-size:23px;font-weight:700;line-height:1.4;margin:46px 0 16px;padding:0 0 10px;border-left:0;border-bottom:1px solid var(--line);background:linear-gradient(var(--brand),var(--brand)) left bottom/44px 3px no-repeat}
.ft-content h3{font-size:17.5px;margin:24px 0 8px;color:var(--ink)}
.ft-content code{background:var(--bg);border:1px solid var(--line);padding:1px 6px;border-radius:2px;font-size:13.5px}
/* 右侧目录：深色标题栏 + 两位编号 */
.ft-side-toc{top:78px}
.ft-side-toc .ft-toc{border:1px solid var(--line);border-radius:0;padding:0;background:#fff}
.ft-side-toc .ft-toc-title{margin:0;padding:9px 14px;background:var(--ink);color:#fff;font-size:13.5px;letter-spacing:1px;border-bottom:2px solid var(--brand)}
.ft-side-toc .ft-toc ol{counter-reset:t;padding:8px 0}
.ft-side-toc .ft-toc li{counter-increment:t;margin:0;font-size:13.5px}
.ft-side-toc .ft-toc a{display:flex;gap:10px;padding:6px 14px;color:#3a3e46;line-height:1.5}
.ft-side-toc .ft-toc a::before{content:counter(t,decimal-leading-zero);font-family:Consolas,Menlo,monospace;color:var(--brand-dark);font-size:12.5px;padding-top:1px}
.ft-side-toc .ft-toc a:hover{background:var(--bg);text-decoration:none;color:var(--ink)}
/* 平台卡片：紧凑行情块，深色顶边，悬停变橙 */
#platforms h2{margin-top:6px}
.ft-cards{grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.ft-card{position:relative;border:1px solid var(--line);border-top:3px solid var(--ink);border-radius:2px;padding:12px 14px 12px;background:#fff;transition:border-color .15s}
.ft-card:hover{border-color:var(--line);border-top-color:var(--brand);box-shadow:none;background:#fffaf5}
.ft-card strong{font-size:15.5px;color:var(--ink);padding-right:18px}
.ft-card strong::after{content:"›";position:absolute;right:14px;top:9px;font-size:20px;color:var(--brand);font-weight:400}
.ft-card span{font-size:13px;line-height:1.55;display:block;margin-top:2px}
/* 要点速览：细框 + 橙色小标签 + 方块项目符号 */
.ft-summary{background:#fff;border:1px solid var(--line);border-left:0;border-right:0;border-top:2px solid var(--ink);border-radius:0;padding:14px 4px 10px}
.ft-summary-title{display:inline-block;background:var(--brand);color:#fff;font-size:13px;padding:1px 10px;letter-spacing:1px;border-radius:2px}
.ft-summary ul{list-style:none;padding:0;margin:8px 0 0}
.ft-summary li{position:relative;padding-left:18px;margin:6px 0}
.ft-summary li::before{content:"";position:absolute;left:2px;top:.72em;width:7px;height:7px;background:var(--brand)}
/* 表格：深色顶线、细线行、斑马纹、紧凑 */
.ft-table-wrap{border:0;border-top:2px solid var(--ink);border-bottom:1px solid var(--line);border-radius:0}
table{font-size:14.5px;font-variant-numeric:tabular-nums}
caption{padding:10px 2px 8px;color:var(--ink);font-size:13.5px}
caption::before{content:"";display:inline-block;width:8px;height:8px;background:var(--brand);margin-right:8px;vertical-align:1px}
th,td{padding:9px 12px;border-top:1px solid var(--line)}
thead th{background:#f1f2f4;color:#4a4f58;font-size:13.5px;letter-spacing:.3px;border-top:1px solid var(--line)}
tbody tr:nth-child(even) td{background:#fafbfc}
tbody tr:hover td{background:#fff6ee}
/* 步骤：方块编号 */
.ft-steps>li{padding-left:40px}
.ft-steps>li::before{border-radius:2px;width:26px;height:26px;background:var(--ink);font-family:Consolas,Menlo,monospace;font-size:13px;top:3px;box-shadow:inset 0 -2px 0 var(--brand)}
/* 配图 */
.ft-hero-figure img{border-radius:2px}
/* 问答：Q 标 */
.ft-faq{border-top:2px solid var(--ink)}
.ft-faq-item{padding:4px 0 6px}
.ft-faq-item h3{position:relative;padding-left:34px;font-size:16.5px}
.ft-faq-item h3::before{content:"Q";position:absolute;left:0;top:1px;width:22px;height:22px;line-height:22px;text-align:center;background:var(--brand);color:#fff;font-size:13px;border-radius:2px;font-family:Consolas,Menlo,monospace}
.ft-faq-item p{padding-left:34px;color:#3d4149}
/* 延伸阅读 */
.ft-related{background:none;border-top:2px solid var(--ink);border-radius:0;padding:16px 0 0}
.ft-related h2{font-size:17px}
.ft-related ul{list-style:none;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 24px}
.ft-related li{margin:3px 0}
.ft-related li a::before{content:"→ ";color:var(--brand)}
/* 页脚：深灰四栏，橙色栏目标题 */
.ft-site-footer{background:#191b20;color:#b4b9c2;padding:44px 0 22px;border-top:3px solid var(--ink-2)}
.ft-site-footer a{color:#c9ced6}
.ft-site-footer a:hover{color:#ffb27a;text-decoration:none}
.ft-footer-grid{grid-template-columns:2.2fr 1fr 1fr 1fr}
.ft-footer-title{color:var(--brand);font-size:13px;letter-spacing:1.5px;border-bottom:1px solid #2e3138;padding-bottom:6px;margin-bottom:10px}
.ft-footer-note{border-top-color:#2e3138;color:#868c96;font-size:12.5px}
@media (max-width:960px){
.ft-banner-inner{grid-template-columns:minmax(0,1fr)}
.ft-banner-art{max-width:620px}
.ft-site-nav ul{height:auto}
.ft-site-nav a{padding:11px 14px;border-bottom:0;border-left:3px solid transparent}
.ft-site-nav a[aria-current=page]{border-left-color:var(--brand)}
.ft-site-nav{top:58px}
}
@media (max-width:640px){
.ft-banner{padding:38px 0 34px}
.ft-banner h1{font-size:30px}
.ft-banner h1::before{width:40px;margin-bottom:12px}
.ft-hero h1{font-size:25px}
.ft-content h2{font-size:20px}
.ft-cards{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
.ft-related ul{grid-template-columns:minmax(0,1fr)}
.ft-footer-grid{grid-template-columns:1fr 1fr}
}