:root{
  --paper: oklch(0.958 0.000 89.9);
  --paper-warm: oklch(0.94 0.008 85);
  --ink: oklch(0.248 0.006 0.6);
  --ink-soft: oklch(0.36 0.01 30);
  --orange: oklch(0.620 0.185 36.7);
  --orange-deep: oklch(0.54 0.16 36.7);
  --gold: oklch(0.576 0.100 75.6);
  --green: oklch(0.385 0.063 158.6);
  --green-tint: oklch(0.92 0.03 158);
  --lime: oklch(0.716 0.147 137.1);
  --bg: var(--paper);
  --text: var(--ink);
  --text-muted: oklch(0.42 0.012 50);
  --surface-dark: var(--ink);
  --surface-dark-2: oklch(0.30 0.008 20);
  --on-dark: var(--paper);
  --on-dark-muted: oklch(0.78 0.01 80);
  --accent: var(--orange);
  --accent-strong: var(--orange-deep);
  --hairline: oklch(0.248 0.006 0.6 / 0.14);
  --hairline-strong: oklch(0.248 0.006 0.6 / 0.3);
  --hairline-dark: oklch(0.958 0.000 89.9 / 0.22);
  --font-display: 'Space Grotesk', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;
  --step--1: clamp(0.78rem, 0.75rem + 0.2vw, 0.85rem);
  --step-0: clamp(1rem, 0.96rem + 0.3vw, 1.13rem);
  --step-1: clamp(1.1rem, 1.1rem + 0.9vw, 1.65rem);
  --step-2: clamp(1.6rem, 1.3rem + 1.8vw, 2.4rem);
  --step-3: clamp(2.1rem, 1.6rem + 3vw, 3.6rem);
  --step-4: clamp(2.4rem, 1.7rem + 4.4vw, 4.1rem);
  --space-s: clamp(1.5rem, 3vw, 2.5rem);
  --space-m: clamp(2.5rem, 5vw, 4rem);
  --space-l: clamp(3.5rem, 8vw, 6.5rem);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:0.01ms !important;transition-duration:0.01ms !important}
}
body{
  font-family:var(--font-display);
  font-weight:300;
  font-size:var(--step-0);
  line-height:1.72;
  color:var(--text);
  background:var(--bg);
  -webkit-font-smoothing:antialiased;
}
::selection{background:var(--accent);color:var(--paper)}
p+p{margin-top:1.15em}
strong{font-weight:500}
a{color:var(--accent-strong);text-decoration:underline;text-underline-offset:4px;text-decoration-thickness:1px;transition:opacity .2s ease-out}
a:hover{opacity:.6}
a:focus-visible,button:focus-visible,summary:focus-visible{outline:2px solid var(--accent);outline-offset:3px;text-decoration:none}
.skip-link{position:absolute;left:-9999px;top:0;background:var(--ink);color:var(--paper);padding:.7rem 1.2rem;z-index:30;font-family:var(--font-mono);font-size:var(--step--1)}
.skip-link:focus{left:1rem;top:1rem}
.progress{position:fixed;top:0;left:0;height:2px;width:100%;background:var(--accent);transform-origin:0 50%;transform:scaleX(0);z-index:25}
.nav{position:sticky;top:0;z-index:20;padding:1rem clamp(1rem,4vw,2.5rem) 0}
.nav-pill{
  max-width:1120px;margin:0 auto;display:flex;align-items:center;gap:1.25rem;
  background:var(--ink);color:var(--paper);border-radius:999px;
  padding:.65rem .7rem .65rem 1.4rem;
}
.brand{font-weight:700;letter-spacing:-0.02em;font-size:1.05rem;color:var(--paper);text-decoration:none;white-space:nowrap}
.brand:hover{opacity:1}
.brand .dot{color:var(--orange)}
.nav-links{display:none;gap:1.4rem;margin-left:auto}
.nav-links a{color:var(--paper);text-decoration:none;font-family:var(--font-mono);font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;transition:opacity .2s ease-out}
.nav-links a:hover{opacity:.5}
.nav-cta{
  margin-left:auto;display:inline-flex;align-items:center;gap:.5rem;
  background:var(--accent);color:var(--paper);text-decoration:none;
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;
  padding:.6rem 1.15rem;border-radius:999px;white-space:nowrap;transition:background .2s ease-out,transform .2s ease-out;
}
.nav-links + .nav-cta{margin-left:0}
.nav-cta:hover{background:var(--accent-strong);opacity:1;transform:translateY(-1px)}
.nav-cta svg{width:.8rem;height:.8rem}
@media (min-width:820px){.nav-links{display:flex}}
.wrap{max-width:1120px;margin:0 auto;padding-left:clamp(1.25rem,5vw,3rem);padding-right:clamp(1.25rem,5vw,3rem)}
section{position:relative}
.pad{padding-top:30px;padding-bottom:20px}
.eyebrow{
  font-family:var(--font-mono);font-size:1rem;font-weight:500;letter-spacing:.14em;text-transform:uppercase;
  color:var(--accent-strong);display:flex;align-items:center;gap:.7rem;margin-bottom:1.4rem;
}
.eyebrow::before{content:"";width:2rem;height:2px;background:var(--accent)}
.dark .eyebrow{color:var(--lime)}
.dark .eyebrow::before{background:var(--lime)}
.hero{background:var(--surface-dark);color:var(--on-dark);margin-top:-3.4rem;padding-top:calc(var(--space-l) + 3.4rem);overflow:hidden}
.hero .wrap{display:grid;gap:var(--space-m)}
.hero h1{color:var(--paper);max-width:18ch}
.hero h1 em{font-style:normal;color:var(--orange)}
.standfirst{font-size:var(--step-1);line-height:1.5;font-weight:300;color:var(--on-dark-muted);max-width:56ch;margin-top:1.6rem}
.hero-meta{display:flex;flex-wrap:wrap;gap:.6rem 2rem;margin-top:1rem;font-family:var(--font-mono);font-size:14px;letter-spacing:.08em;text-transform:uppercase;}
.hero-meta span{display:inline-flex;align-items:center;gap:.55rem}
.hero-meta i{width:.45rem;height:.45rem;border-radius:50%;background:var(--orange);display:inline-block}
.hero-figure{margin-top:var(--space-m);border:1px solid var(--hairline-dark);border-radius:1.25rem;padding:clamp(1rem,3vw,2.2rem);background:var(--surface-dark-2)}
.hero-figure svg{width:100%;height:auto;display:block}
figcaption{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.06em;color:var(--on-dark-muted);margin-top:1rem}
.article-lede{font-size:22px;line-height:1.55;font-weight:300;}
.article-lede strong{font-weight:500}
.split{display:grid;gap:var(--space-m);margin-top:var(--space-m)}
@media (min-width:900px){.split{grid-template-columns:7fr 5fr;align-items:start}}
.rule{border:0;border-top:1px solid var(--hairline);max-width:1120px;margin:0 auto}
.crit{display:grid;gap:1.2rem;margin-top:var(--space-s)}
@media (min-width:760px){.crit{grid-template-columns:repeat(3,1fr)}}
.crit-item{border-top:2px solid var(--ink);padding-top:1.3rem}
.crit-item .k{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;color:var(--gold);display:block;margin-bottom:.7rem;text-transform:uppercase}
.crit-item h3{margin:0 0 .7rem;font-size:1.15rem}
.crit-item p{margin:0;font-size:.95rem}
.figure-card{border:1px solid var(--hairline);border-radius:1.25rem;padding:clamp(1.2rem,3vw,2rem);background:var(--paper-warm)}
.figure-card svg{width:100%;height:auto;display:block}
.figure-card figcaption{color:var(--text-muted)}
.cmp h3{margin-top:var(--space-s)}
.table-scroll{overflow-x:auto;margin-top:var(--space-s);border:1px solid var(--hairline-strong);border-radius:1rem;-webkit-overflow-scrolling:touch}
table{border-collapse:collapse;width:100%;min-width:820px;font-size:.95rem;background:var(--paper)}
caption{text-align:left;font-family:var(--font-mono);font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;color:var(--text-muted);padding:1rem 1.2rem .4rem}
th,td{padding:.95rem 1.2rem;text-align:left;vertical-align:top;border-top:1px solid var(--hairline);line-height:1.45}
thead th{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.08em;text-transform:uppercase;font-weight:500;color:var(--paper);background:var(--ink);border-top:0;white-space:nowrap}
tbody th{font-weight:500;white-space:nowrap}
tr.hl th, tr.hl td{background:var(--green-tint);border-top:1px solid var(--green)}
tr.hl th{color:var(--green);font-weight:700}
tr.hl td:first-of-type{border-left:3px solid var(--green)}
td.good{color:var(--green);font-weight:500}
.dark{background:var(--surface-dark);color:var(--on-dark)}
.dark h2,.dark h3{color:var(--paper)}
.dark p{color:var(--on-dark-muted)}
.dark strong{color:var(--paper)}
.adv{display:grid;gap:0;}
.adv-item{border-top:1px solid var(--hairline);padding:1rem 0;display:grid;gap:1rem}
@media (min-width:820px){.adv-item{grid-template-columns:5fr 7fr;gap:3rem}}
.adv-item h3{margin:0}
.adv-item h3 span{color:var(--orange)}
.adv-item p{margin:0}
.choose{border:1px solid var(--hairline);border-radius:1.25rem;padding:clamp(1.5rem,4vw,2.5rem);background:var(--paper-warm);margin-top:var(--space-s)}
.choose p{margin:0}
.choose p+p{margin-top:1.15em}
.trend{display:grid;gap:var(--space-m);margin-top:var(--space-s)}
.trend-item{border-top:1px solid var(--hairline-strong);padding-top:1.6rem;display:grid;gap:1.2rem}
@media (min-width:820px){.trend-item{grid-template-columns:1fr 2fr;gap:3rem}}
.trend-item h3{margin:0}
.trend-item p{margin:.8rem 0 0}
.faq{margin-top:var(--space-s)}
details{border-top:1px solid var(--hairline-strong)}
details:last-child{border-bottom:1px solid var(--hairline-strong)}
summary{
  list-style:none;cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:1.5rem;
  padding:1.4rem .2rem;font-weight:500;font-size:24px;letter-spacing:-0.01em;line-height:1.3;min-height:44px;
}
summary::-webkit-details-marker{display:none}
summary .ic{flex:none;width:1.6rem;height:1.6rem;position:relative}
summary .ic::before,summary .ic::after{content:"";position:absolute;inset:0;margin:auto;background:var(--accent);width:1.1rem;height:2px;transition:transform .2s ease-out}
summary .ic::after{transform:rotate(90deg)}
details[open] summary .ic::after{transform:rotate(0deg)}
details .body{padding:0 .2rem 1.6rem;max-width:68ch}
details .body p{margin:0}
.cta{background:var(--surface-dark);color:var(--on-dark);overflow:hidden}
.cta .wrap{position:relative;padding-top:var(--space-l);padding-bottom:var(--space-l)}
.cta h2{color:var(--paper);max-width:16ch}
.cta h2 em{font-style:normal;color:var(--orange)}
.cta p{color:var(--on-dark-muted);margin-top:1.4rem}
.cta-row{display:flex;flex-wrap:wrap;gap:1.2rem;margin-top:2.4rem;align-items:center}
.btn{
  display:inline-flex;align-items:center;gap:.7rem;border-radius:999px;text-decoration:none;
  font-family:var(--font-mono);font-size:.8rem;letter-spacing:.08em;text-transform:uppercase;
  padding:1rem 1.9rem;min-height:44px;transition:transform .2s ease-out,background .2s ease-out,color .2s ease-out;
}
.btn svg{width:.9rem;height:.9rem;transition:transform .2s ease-out}
.btn:hover svg{transform:translateX(3px)}
.btn-primary{background:var(--accent);color:var(--paper);font-size:16px;}
.btn-primary:hover{background:var(--accent-strong);opacity:1;transform:translateY(-2px)}
.btn-ghost{background:var(--green);color:var(--paper);font-size:16px;}
.btn-ghost:hover{background:var(--green);opacity:1;transform:translateY(-2px)}
.cta-art{position:absolute;right:-14%;bottom:-22%;width:min(46rem,72vw);opacity:.5;pointer-events:none}
.cta-art svg{width:100%;height:auto;display:block}
.section-title {font-size:28px;}