:root{--bg:#f5f8ff;--card:#fff;--ink:#0d1117;--muted:#5b6573;--primary:#1f6feb;--primary2:#1272d9;--line:#dce5f2;--soft:#eaf2ff;--max:1120px;--radius:18px}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.68}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}img{max-width:100%;height:auto}button,input,select{font:inherit}
.top,.site-header{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line)}
.nav{max-width:var(--max);margin:auto;padding:12px 20px;display:flex;gap:18px;align-items:center;justify-content:space-between;flex-wrap:wrap}.brand{display:flex;gap:10px;align-items:center;color:var(--ink);font-weight:800;white-space:nowrap}.brand img{width:170px;height:auto;display:block}.navlinks,.site-header .nav{display:flex;gap:16px;flex-wrap:wrap;align-items:center}.navlinks a,.site-header .nav a{font-size:14px;font-weight:600;color:#344054}.site-header .nav .brand{margin-right:auto}
.wrap{max-width:var(--max);margin:auto;padding:46px 20px 70px}.article-wrap{max-width:900px}.crumb,.breadcrumbs{font-size:13px;margin-bottom:18px;color:var(--muted)}.crumb a,.breadcrumbs a{color:var(--muted)}
.hero{background:linear-gradient(135deg,#eaf2ff,#fff);border:1px solid var(--line);border-radius:24px;padding:42px 34px;margin-bottom:28px}.eyebrow,.kicker{font-size:12px;letter-spacing:.09em;text-transform:uppercase;font-weight:800;color:var(--primary);margin-bottom:10px}.hero h1,h1{margin:0 0 14px;font-size:clamp(32px,5vw,56px);line-height:1.08;letter-spacing:-.03em}.hero p,.intro{font-size:18px;color:var(--muted);max-width:850px;margin:0}
.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px}.card h2,.card h3{margin-top:0;line-height:1.25}.card p:last-child{margin-bottom:0}
.prose{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:30px}.prose h2{font-size:28px;margin:34px 0 12px}.prose h3{font-size:21px;margin:26px 0 10px}.prose p{margin:10px 0}.prose ul,.prose ol{padding-left:22px}.toc{background:var(--soft);border:1px solid #c7dbff;border-radius:16px;padding:20px;margin:20px 0}.toc strong{display:block;margin-bottom:7px}.cta,.button{display:inline-block;background:var(--primary);color:#fff!important;font-weight:800;border:0;border-radius:12px;padding:12px 18px;margin-top:20px;cursor:pointer;text-decoration:none}.button.secondary{background:#eef4fb;color:#18304b!important;border:1px solid var(--line)}
.notice{background:#fff8e8;border:1px solid #f2d28a;border-radius:14px;padding:16px 18px;color:#5d4a1c}.updated,.meta{font-size:13px;color:var(--muted)}.article-meta{display:flex;gap:12px;flex-wrap:wrap;color:var(--muted);font-size:14px;margin-bottom:20px}.cover{display:block;width:100%;max-height:500px;object-fit:cover;border-radius:18px;margin:24px 0;border:1px solid var(--line)}
.table-wrap{overflow:auto}.table{width:100%;border-collapse:separate;border-spacing:0;border:1px solid var(--line);border-radius:14px;overflow:hidden;background:#fff}.table th,.table td{padding:12px 14px;text-align:left;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}.table th:last-child,.table td:last-child{border-right:0}.table tr:last-child td{border-bottom:0}.faq details{border-top:1px solid var(--line);padding:16px 0}.faq details:first-child{border-top:0}.faq summary{cursor:pointer;font-weight:800}.source-note{font-size:14px;color:var(--muted)}
.site-header .nav{max-width:1100px;padding:14px 18px}.article-wrap p,.article-wrap li{font-size:17px}.related{display:flex;gap:10px;flex-wrap:wrap}.related a{background:var(--soft);border-radius:999px;padding:8px 12px;font-size:14px;font-weight:700}
.footer{border-top:1px solid var(--line);background:#fff}.footer-inner{max-width:var(--max);margin:auto;padding:34px 20px;display:grid;gap:22px}.footer-links{display:flex;flex-wrap:wrap;gap:14px;font-size:14px}
.tool{background:#fff;border:1px solid var(--line);border-radius:22px;padding:28px;margin:24px 0}.tool-head{display:flex;justify-content:space-between;gap:16px;align-items:flex-start;flex-wrap:wrap}.tool h2{margin:0 0 4px}.field-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.field{display:flex;flex-direction:column;gap:7px}.field label{font-weight:700;font-size:14px}.field input,.field select{width:100%;padding:12px 13px;border:1px solid #cbd5e1;border-radius:11px;background:#fff;color:var(--ink)}.field input:focus,.field select:focus{outline:2px solid rgba(31,111,235,.2);border-color:var(--primary)}.result{margin-top:20px;padding:18px;border:1px solid #c7dbff;background:#f7fbff;border-radius:14px}.result strong{color:#0f55b5}.result-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin-top:14px}.result-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px}.result-card b{display:block;font-size:20px}.tag{display:inline-block;padding:5px 9px;border-radius:999px;background:var(--soft);color:#184a8b;font-weight:700;font-size:12px}.quiz-q{padding:16px 0;border-top:1px solid var(--line)}.quiz-q:first-child{border-top:0}.quiz-q label{display:block;padding:9px 10px;margin:7px 0;background:#f8fafc;border:1px solid var(--line);border-radius:10px}.range-row{display:grid;grid-template-columns:1fr auto;gap:12px;align-items:center}.sound-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.sound-card{padding:18px;border:1px solid var(--line);border-radius:15px;background:#fff}.sound-card button{margin-top:8px}.shop-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.shop-card img{aspect-ratio:16/10;object-fit:cover;border-radius:12px;background:#eef4fb}.shop-card h3{margin:12px 0 6px}.shop-card .price{font-weight:800;color:#143d78}
.small{font-size:14px;color:var(--muted)}.center{text-align:center}.sr-only{position:absolute!important;width:1px!important;height:1px!important;padding:0!important;margin:-1px!important;overflow:hidden!important;clip:rect(0,0,0,0)!important;white-space:nowrap!important;border:0!important}
@media(max-width:850px){.grid-3,.shop-grid,.sound-grid,.result-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.navlinks{gap:11px}}
@media(max-width:640px){.nav{padding:10px 14px}.navlinks,.site-header .nav{gap:9px}.navlinks a,.site-header .nav a{font-size:12px}.brand img{width:150px}.wrap{padding:28px 16px 55px}.hero{padding:28px 22px}.prose,.tool{padding:21px}.grid,.field-grid,.grid-3,.shop-grid,.sound-grid,.result-grid{grid-template-columns:1fr}.hero h1,h1{font-size:34px}.hero p,.intro,.article-wrap p,.article-wrap li{font-size:16px}.cover{border-radius:12px}.button,.cta{width:100%;text-align:center}}