/* Direction A — "Poster": black, heavy sans, one signal yellow. System fonts only (no external requests). */
:root{--bg:#0b0b0c;--bg2:#131315;--card:#171719;--ink:#f5f5f4;--mute:#a1a1a8;--line:#2b2b30;--sig:#ffd60a;--sig-ink:#0b0b0c;--warn:#ffd60a;--bad:#ff6b6b}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:72px;color-scheme:dark}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 "Helvetica Neue",Helvetica,Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC","Noto Sans SC",sans-serif;-webkit-font-smoothing:antialiased}
h1,h2,h3,h4{font-weight:800;line-height:1.12;margin:0 0 .5em;letter-spacing:-.02em}
a{color:var(--sig);text-underline-offset:3px}
.wrap{max-width:1120px;margin:0 auto;padding:0 28px}.narrow{max-width:780px}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:12px;background:var(--sig);color:#000;padding:8px 12px;z-index:99}
.nav{position:sticky;top:0;z-index:20;background:rgba(11,11,12,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;gap:28px;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;color:var(--ink);text-decoration:none;letter-spacing:-.01em}
.brand .dim{color:var(--mute);font-weight:600}
.mark{width:14px;height:14px;background:var(--sig);display:inline-block}
.links{display:flex;gap:26px;margin-left:auto}.links a{color:var(--mute);text-decoration:none;font-size:14.5px;font-weight:600}.links a:hover{color:var(--sig)}
.lang{display:flex;border:1px solid #3a3a40;border-radius:6px;overflow:hidden}
.lang button{border:0;background:none;padding:7px 13px;font:700 13px inherit;font-family:inherit;color:var(--mute);cursor:pointer}
.lang button[aria-pressed=true]{background:var(--sig);color:var(--sig-ink)}
.hero{padding:104px 0 84px;border-top:6px solid var(--sig);background:linear-gradient(180deg,#0b0b0c 0,#0b0b0c 60%,#111113 100%)}
.eyebrow{display:inline-block;font-size:13px;letter-spacing:.1em;text-transform:uppercase;color:var(--sig-ink);background:var(--sig);font-weight:800;margin:0 0 26px;padding:5px 10px}
.hero h1{font-size:clamp(34px,5.3vw,68px);font-weight:900;line-height:1.1;letter-spacing:-.03em;margin-bottom:30px;color:var(--ink);text-wrap:balance}
.hero h1 .l2{color:var(--sig);display:inline-block;margin-top:.12em}
.hero h1 .l1,.hero h1 .l2{text-wrap:balance}
.lead{font-size:clamp(17px,2vw,21px);color:#cfcfd4;max-width:40em;margin:0 0 36px}
.cta{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:56px}
.btn{display:inline-block;border-radius:6px;padding:15px 28px;font:800 16px inherit;font-family:inherit;text-decoration:none;cursor:pointer;border:2px solid transparent;transition:transform .12s,background .12s}
.btn.primary{background:var(--sig);color:var(--sig-ink)}.btn.primary:hover{transform:translateY(-2px);background:#ffe047}
.btn.ghost{background:transparent;color:var(--ink);border-color:#4a4a52}.btn.ghost:hover{border-color:var(--sig);color:var(--sig)}
.btn.small{padding:9px 18px;font-size:14px;background:var(--sig);color:var(--sig-ink)}
.stats{display:flex;gap:64px;flex-wrap:wrap;border-top:1px solid var(--line);padding-top:28px}
.stats div{display:flex;flex-direction:column}.stats strong{font-size:64px;line-height:1;font-weight:900;letter-spacing:-.04em;color:var(--ink)}.stats span{color:var(--mute);font-size:14px;margin-top:8px;font-weight:600}
.note{color:var(--mute);font-size:13.5px;margin:20px 0 0}
.sec{padding:96px 0;border-top:1px solid var(--line)}.alt{background:var(--bg2)}
.sec h2{font-size:clamp(30px,4.6vw,52px);font-weight:900;letter-spacing:-.03em}
.sub{color:var(--mute);max-width:44em;margin:0 0 44px;font-size:17px}
.cards{list-style:none;padding:0;margin:0;display:grid;gap:16px}
.demands{grid-template-columns:repeat(auto-fit,minmax(310px,1fr));counter-reset:d}
.demands li{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:28px;counter-increment:d;border-top:3px solid var(--sig)}
.demands li::before{content:"0" counter(d);font-weight:900;font-size:40px;line-height:1;color:var(--sig);display:block;margin-bottom:18px;letter-spacing:-.03em}
.demands h3{font-size:20px}.demands p{margin:0;color:#c3c3c9;font-size:15.5px}
.demo-banner{border:1px dashed var(--sig);color:var(--sig);border-radius:8px;padding:11px 15px;font-size:14px;margin-bottom:26px}
form{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:34px}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:0 22px}
.field{margin-bottom:20px}label{display:block;font-weight:700;font-size:14px;margin-bottom:7px;color:#e6e6e8}
input,select,textarea{width:100%;font:16px inherit;font-family:inherit;padding:12px 14px;border:1px solid #3a3a40;border-radius:6px;background:#0e0e10;color:var(--ink)}
select option{background:#0e0e10}
input[type=month]{color-scheme:dark}
input:focus,select:focus,textarea:focus{outline:2px solid var(--sig);outline-offset:1px;border-color:var(--sig)}
.field.bad input,.field.bad select{border-color:var(--bad)}
.err{color:var(--bad);font-size:13px;margin:6px 0 0}.err:empty{display:none}
.checks{margin:6px 0 24px}.check{display:flex;gap:11px;align-items:flex-start;font-weight:400;margin-bottom:11px;font-size:15px;color:#d6d6da}
.check input{width:19px;height:19px;margin-top:3px;flex:none;accent-color:var(--sig)}
.fine{color:var(--mute);font-size:13.5px;margin:16px 0 0}
.thanks{background:var(--card);border:1px solid var(--line);border-left:5px solid var(--sig);border-radius:12px;padding:30px}
.thanks[hidden]{display:none}
.tag-demo{display:inline-block;font-size:13.5px;color:var(--sig);margin:0 0 20px;font-weight:600}
.cases{grid-template-columns:repeat(auto-fit,minmax(290px,1fr))}
.case{background:var(--card);border:1px dashed #44444b;border-radius:10px;padding:26px;position:relative;display:flex;flex-direction:column}
.badge{position:absolute;top:16px;right:16px;font-size:11.5px;font-weight:800;color:var(--sig-ink);background:var(--sig);padding:3px 9px;border-radius:3px}
.case h3{font-size:18px;padding-right:84px}.case p{color:#c3c3c9;font-size:15px}
.case dl{display:flex;gap:30px;margin:auto 0 0;padding-top:18px;font-size:13.5px}.case dt{color:var(--mute)}.case dd{margin:0;font-weight:700}
.verify{font-size:13.5px;color:var(--mute);margin:-24px 0 26px}
.guide{display:grid;gap:12px}
.acc{background:var(--card);border:1px solid var(--line);border-radius:10px}
.acc>summary{cursor:pointer;padding:22px 26px;font-weight:800;font-size:19px;list-style:none;display:flex;justify-content:space-between;gap:12px;letter-spacing:-.01em}
.acc>summary::-webkit-details-marker,.faq>summary::-webkit-details-marker{display:none}
.acc>summary::after,.faq>summary::after{content:"+";font:400 28px/1 Arial;color:var(--sig);flex:none}
details[open]>summary::after{content:"\2013"}
.acc[open]{border-color:#4a4a52}
.acc .body{padding:20px 26px 26px;border-top:1px solid var(--line)}
.body ol,.body ul{padding-left:22px;margin:0 0 14px}.body li{margin-bottom:9px;font-size:15.5px;color:#d6d6da}
.body h4{font-size:16px;margin:24px 0 8px}
.src{font-size:13.5px;color:var(--mute);margin:12px 0}.ok{color:var(--sig);font-weight:800}
.src.warn{color:var(--sig);background:rgba(255,214,10,.08);border:1px solid rgba(255,214,10,.3);border-radius:6px;padding:9px 13px}
.hint{font-size:14px;color:var(--mute);margin:0 0 9px}
.tpl{font:14px/1.6 ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;resize:vertical}
.row{display:flex;align-items:center;gap:14px;margin-top:12px}.copied{font-size:14px;color:var(--sig);font-weight:700}
.alt-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin:14px 0 8px}
.alt-grid div{border:1px solid var(--line);border-radius:8px;padding:18px;background:#0e0e10}
.alt-grid h4{margin:0 0 6px;font-size:16px}.alt-grid p{margin:0 0 9px;font-size:14px;color:#c3c3c9}.alt-grid a{font-size:14px}
.faq{border-bottom:1px solid var(--line)}.faq>summary{cursor:pointer;list-style:none;padding:22px 0;font-weight:700;font-size:18px;display:flex;justify-content:space-between;gap:12px}
.faq p{margin:0 0 22px;color:#c3c3c9}
.plain{padding-left:20px}.plain li{margin-bottom:9px;color:#d6d6da}
.foot{padding:52px 0 60px;font-size:14px;background:var(--sig);color:#1a1a1a}
.foot strong{color:#000}.foot .dim{opacity:.7}
@media(max-width:820px){.links{display:none}.lang{margin-left:auto}}
@media(max-width:640px){.wrap{padding:0 20px}.hero{padding:60px 0 52px}.sec{padding:64px 0}.grid2{grid-template-columns:1fr}form{padding:22px}.stats{gap:36px}.stats strong{font-size:48px}.btn{width:100%;text-align:center}.cta{flex-direction:column}.btn.small{width:auto}.hero h1{font-size:clamp(30px,8.4vw,44px)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.btn{transition:none}}
.hero h1 .l1{word-break:keep-all}