:root{--ink:#101315;--muted:#687174;--soft:#f2f5f4;--line:#dfe5e3;--lime:#c8f000;--orange:#ff7a2f;--blue:#d9f1ff;--white:#fff;--shadow:0 28px 80px rgba(12,18,17,.12)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:#fff;color:var(--ink);font-family:Manrope,"Noto Sans SC",system-ui,sans-serif;font-size:16px;line-height:1.7}a{color:inherit;text-decoration:none}button,input{font:inherit}.shell{width:min(1160px,calc(100% - 40px));margin:auto}
.topbar{height:72px;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:12px;font-weight:800;font-size:20px;letter-spacing:-.03em}.mark{width:36px;height:36px;border-radius:12px;background:var(--ink);display:grid;place-items:center;color:var(--lime)}.topnav{display:flex;align-items:center;gap:28px;font-size:14px;font-weight:700}.topnav a:hover{color:#647800}.home-pill{background:var(--ink);color:#fff;padding:10px 16px;border-radius:999px}
.guide-hero{background:#0f1314;color:#fff;padding:70px 0 76px;overflow:hidden;position:relative}.guide-hero::after{content:"";position:absolute;width:560px;height:560px;border-radius:50%;border:1px solid rgba(200,240,0,.22);right:-240px;top:-300px;box-shadow:0 0 0 80px rgba(200,240,0,.025),0 0 0 160px rgba(200,240,0,.015)}.crumbs{display:flex;gap:10px;color:#9ea7a5;font-size:13px}.crumbs a:hover{color:var(--lime)}.hero-grid{position:relative;z-index:1;display:grid;grid-template-columns:1.35fr .65fr;gap:60px;align-items:end;margin-top:54px}.eyebrow{color:var(--lime);font-size:12px;text-transform:uppercase;letter-spacing:.18em;font-weight:800}.guide-hero h1{font-size:clamp(46px,7vw,78px);letter-spacing:-.065em;line-height:1.04;margin:18px 0 24px}.guide-hero p{font-size:18px;color:#c5ccca;max-width:700px;margin:0}.hero-meta{display:grid;gap:12px}.meta-item{border-top:1px solid #343b3c;padding-top:12px}.meta-item span{display:block;color:#8d9795;font-size:12px}.meta-item b{font-size:14px}
.jumpbar{position:sticky;top:0;background:rgba(255,255,255,.94);backdrop-filter:blur(14px);border-bottom:1px solid var(--line);z-index:10}.jumpbar-inner{display:flex;gap:28px;overflow:auto;padding:14px 0;white-space:nowrap;font-size:14px;font-weight:700}.jumpbar a:hover{color:#647800}
main section{padding:80px 0}.section-head{display:grid;grid-template-columns:.8fr 1.2fr;gap:50px;align-items:end;margin-bottom:34px}.kicker{color:#647800;font-size:12px;text-transform:uppercase;letter-spacing:.16em;font-weight:800}.section-head h2{font-size:clamp(34px,4vw,54px);letter-spacing:-.055em;line-height:1.12;margin:10px 0 0}.section-head p{color:var(--muted);max-width:640px;margin:0}
.symptom-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.symptom-card{border:1px solid var(--line);border-radius:18px;padding:22px;min-height:150px}.symptom-card strong{font-size:18px;display:block;margin-bottom:8px}.symptom-card p{color:var(--muted);margin:0;font-size:14px}.symptom-card.good{background:var(--lime);border-color:var(--lime)}.symptom-card.good p{color:#394600}.symptom-card.danger{background:#fff2ec;border-color:#ffd2bd}
.figure-wrap{position:relative;border-radius:28px;overflow:hidden;background:#e9eeee;box-shadow:var(--shadow)}.figure-wrap.dark{background:#0d1012}.figure-wrap img{display:block;width:100%;height:auto}.callout{position:absolute;display:flex;align-items:center;gap:8px;background:rgba(15,19,20,.92);color:#fff;padding:9px 12px;border-radius:12px;font-size:13px;font-weight:700;box-shadow:0 8px 30px rgba(0,0,0,.2)}.callout::before{content:"";width:9px;height:9px;background:var(--lime);border-radius:50%;box-shadow:0 0 0 5px rgba(200,240,0,.2)}.figure-caption{display:flex;justify-content:space-between;gap:20px;padding:18px 4px 0;color:var(--muted);font-size:13px}.figure-caption b{color:var(--ink)}
.tools{display:flex;gap:10px;flex-wrap:wrap;margin-top:22px}.tool{padding:9px 13px;border:1px solid var(--line);border-radius:999px;font-size:13px;font-weight:700;background:#fff}.tool.optional{color:var(--muted);font-weight:600}
.steps-section{background:var(--soft)}.step-list{display:grid;gap:12px}.step-card{background:#fff;border:1px solid var(--line);border-radius:20px;padding:24px;display:grid;grid-template-columns:54px 1fr;gap:18px}.step-num{width:48px;height:48px;border-radius:15px;background:var(--ink);color:var(--lime);display:grid;place-items:center;font-size:18px;font-weight:800}.step-card h3{margin:0 0 7px;font-size:21px}.step-card p{margin:0;color:var(--muted)}.step-card ul{margin:10px 0 0;padding-left:20px;color:#46504e}.step-card li+li{margin-top:5px}.check{margin-top:14px;background:#f7f9f8;border-left:3px solid var(--lime);padding:11px 14px;border-radius:0 10px 10px 0;font-size:14px}.check b{color:#516300}
.logic-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}.logic-card{border:1px solid var(--line);border-radius:20px;padding:24px}.logic-card h3{margin:0 0 14px;font-size:20px}.logic-flow{display:grid;gap:9px}.logic-row{display:grid;grid-template-columns:1fr auto;gap:18px;padding:11px 0;border-top:1px solid var(--line);font-size:14px}.logic-row span:last-child{font-weight:800}.turn-ccw{color:#587000}.turn-cw{color:#a34a20}
.alert{background:#131718;color:#fff;border-radius:24px;padding:30px;display:grid;grid-template-columns:48px 1fr;gap:18px}.alert-icon{width:44px;height:44px;border-radius:50%;background:var(--orange);display:grid;place-items:center;font-weight:800}.alert h3{margin:0 0 8px;font-size:22px}.alert p{margin:0;color:#bdc5c3}.alert ul{margin:12px 0 0;padding-left:20px;color:#e0e5e4}
.source-box{background:var(--blue);border-radius:24px;padding:30px}.source-box h2{margin:0 0 8px;font-size:27px}.source-box p{margin:0 0 18px;color:#526167}.source-links{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.source-link{background:#fff;border-radius:14px;padding:15px 17px;display:flex;justify-content:space-between;gap:16px;font-weight:700}.source-link small{display:block;color:var(--muted);font-weight:500}.source-link:hover{transform:translateY(-2px)}
.next-guides{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.next-guide{border:1px solid var(--line);border-radius:20px;padding:22px;min-height:170px;display:flex;flex-direction:column}.next-guide:hover{border-color:#9bb800;box-shadow:var(--shadow)}.next-guide span{font-size:12px;color:#647800;font-weight:800}.next-guide h3{margin:14px 0 8px;font-size:21px}.next-guide p{margin:0;color:var(--muted);font-size:14px}.next-guide b{margin-top:auto;padding-top:18px}
.noise-controls{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:22px}.noise-btn{border:1px solid var(--line);background:#fff;padding:10px 15px;border-radius:999px;font-weight:700;cursor:pointer}.noise-btn:hover,.noise-btn.active{background:var(--ink);color:#fff;border-color:var(--ink)}.noise-results{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:18px}.noise-result{border:1px solid var(--line);border-radius:16px;padding:18px;background:#fff}.noise-result strong{display:block}.noise-result small{color:var(--muted)}.noise-hotspot{position:absolute;width:30px;height:30px;border:0;border-radius:50%;background:var(--lime);color:var(--ink);font-weight:800;box-shadow:0 0 0 7px rgba(200,240,0,.18);cursor:pointer}.noise-hotspot:hover,.noise-hotspot.active{transform:scale(1.15);box-shadow:0 0 0 10px rgba(200,240,0,.24)}
footer{padding:46px 0;border-top:1px solid var(--line)}.footer-row{display:flex;align-items:center;justify-content:space-between;gap:20px;color:var(--muted);font-size:13px}
@media(max-width:850px){.topnav a:not(.home-pill){display:none}.hero-grid,.section-head{grid-template-columns:1fr}.hero-grid{gap:28px}.symptom-strip,.noise-results{grid-template-columns:1fr}.logic-grid,.source-links{grid-template-columns:1fr}.next-guides{grid-template-columns:1fr}.section-head{gap:18px}.callout{font-size:11px;padding:7px 9px}.figure-caption{flex-direction:column}.hero-meta{grid-template-columns:1fr 1fr}.noise-hotspot{width:26px;height:26px}}
@media(max-width:560px){.shell{width:min(100% - 24px,1160px)}.topbar{height:62px}.guide-hero{padding:46px 0 56px}.hero-grid{margin-top:38px}.hero-meta{grid-template-columns:1fr}.jumpbar-inner{gap:20px}.step-card{grid-template-columns:1fr}.figure-wrap{border-radius:18px}.callout{position:static;margin:8px;display:inline-flex}.figure-caption{padding:14px 2px 0}.noise-hotspot{width:24px;height:24px;font-size:12px}.alert{grid-template-columns:1fr}.footer-row{align-items:flex-start;flex-direction:column}}