:root {
  --ink: #162033;
  --muted: #667085;
  --line: #dfe5ee;
  --paper: #ffffff;
  --wash: #f5f7fb;
  --blue: #2457d6;
  --blue-soft: #eaf0ff;
  --orange: #d86b2f;
  --green: #16715a;
  --shadow: 0 18px 50px rgba(22, 32, 51, .09);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--wash); line-height: 1.65; }
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
.shell { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.topbar { position: sticky; top: 0; z-index: 10; border-bottom: 1px solid rgba(223,229,238,.9); background: rgba(245,247,251,.9); backdrop-filter: blur(14px); }
.topbar-inner { display: flex; align-items: center; justify-content: space-between; min-height: 64px; gap: 20px; }
.brand { color: var(--ink); font-weight: 800; letter-spacing: -.02em; }
.nav { display: flex; align-items: center; gap: 18px; font-size: .92rem; }
.lang-toggle { border: 1px solid var(--line); background: var(--paper); color: var(--ink); border-radius: 999px; padding: 6px 12px; cursor: pointer; }
.hero { padding: 86px 0 58px; }
.eyebrow { color: var(--blue); font-size: .83rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
h1 { max-width: 920px; margin: 12px 0 18px; font-size: clamp(2.2rem, 5vw, 4.7rem); line-height: 1.06; letter-spacing: -.055em; }
.dek { max-width: 790px; color: #445066; font-size: 1.14rem; }
.authors { margin: 18px 0 0; color: var(--muted); }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0 0; }
.button { display: inline-flex; align-items: center; gap: 8px; border-radius: 10px; padding: 10px 15px; border: 1px solid var(--line); background: var(--paper); color: var(--ink); font-weight: 700; }
.button.primary { color: #fff; border-color: var(--blue); background: var(--blue); }
.button:hover { text-decoration: none; transform: translateY(-1px); box-shadow: 0 7px 20px rgba(36,87,214,.15); }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 26px; align-items: end; }
.hero-visual { border: 1px solid var(--line); border-radius: 18px; padding: 12px; background: var(--paper); box-shadow: var(--shadow); }
.hero-visual img { display: block; width: 100%; border-radius: 10px; }
.caption { margin: 10px 4px 0; color: var(--muted); font-size: .82rem; }
section { padding: 62px 0; }
.section-head { display: flex; justify-content: space-between; align-items: end; gap: 20px; margin-bottom: 24px; }
h2 { margin: 0; font-size: clamp(1.65rem, 3vw, 2.55rem); letter-spacing: -.035em; line-height: 1.15; }
.section-head p { max-width: 560px; margin: 0; color: var(--muted); }
.panel { border: 1px solid var(--line); border-radius: 18px; padding: 26px; background: var(--paper); box-shadow: 0 10px 30px rgba(22,32,51,.04); }
.problem { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.problem .panel strong { display: block; margin-bottom: 6px; font-size: 1.08rem; }
.pipeline { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; align-items: stretch; }
.step { position: relative; padding: 17px 14px; border: 1px solid var(--line); border-radius: 14px; background: var(--paper); }
.step:not(:last-child)::after { content: "→"; position: absolute; right: -18px; top: 35%; color: var(--orange); font-size: 1.35rem; font-weight: 800; }
.step b { display: block; color: var(--blue); font-size: .78rem; letter-spacing: .08em; text-transform: uppercase; }
.step span { display: block; margin-top: 8px; font-weight: 700; line-height: 1.35; }
.metrics { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.metric { padding: 23px; border-radius: 16px; border: 1px solid var(--line); background: var(--paper); }
.metric .number { color: var(--blue); font-size: 2.25rem; font-weight: 850; letter-spacing: -.05em; }
.metric p { margin: 5px 0 0; color: var(--muted); font-size: .93rem; }
.comparison { width: 100%; border-collapse: collapse; overflow: hidden; border: 1px solid var(--line); border-radius: 14px; background: var(--paper); }
.comparison th, .comparison td { padding: 13px 15px; border-bottom: 1px solid var(--line); text-align: left; }
.comparison th { color: var(--muted); background: #f8faff; font-size: .84rem; text-transform: uppercase; letter-spacing: .07em; }
.comparison tr:last-child td { border-bottom: 0; }
.tag { display: inline-block; border-radius: 999px; padding: 3px 9px; background: var(--blue-soft); color: var(--blue); font-size: .78rem; font-weight: 800; }
.repro { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
pre { overflow: auto; margin: 0; padding: 18px; border-radius: 12px; background: #111827; color: #e8eefb; font-size: .86rem; }
.note { border-left: 4px solid var(--orange); padding: 9px 0 9px 16px; color: #4e596d; }
.cite { position: relative; }
.copy { position: absolute; right: 12px; top: 12px; border: 1px solid #41506b; background: #202b40; color: #fff; border-radius: 7px; padding: 5px 9px; cursor: pointer; }
footer { padding: 32px 0 52px; color: var(--muted); font-size: .88rem; }
body.lang-zh .en, body.lang-en .zh { display: none; }
@media (max-width: 820px) { .hero-grid, .problem, .repro { grid-template-columns: 1fr; } .pipeline { grid-template-columns: 1fr; } .step:not(:last-child)::after { content: "↓"; right: 50%; top: auto; bottom: -25px; } .metrics { grid-template-columns: 1fr; } .nav a { display: none; } .hero { padding-top: 56px; } }