:root{--bg:#ffffff;--ink:#0b1220;--muted:#475569;--brand:#2563eb;--border:#e2e8f0;--card:#ffffff;--shadow:0 10px 24px rgba(2,6,23,.07)}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--ink);font:16px/1.65 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Ubuntu,"Helvetica Neue",Arial}
a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
.header{position:sticky;top:0;z-index:20;background:#fff;border-bottom:1px solid var(--border)}
.header .wrap{max-width:1200px;margin:0 auto;padding:14px 24px;display:flex;justify-content:space-between;align-items:center}
.logo{font-weight:900;font-size:1.25rem;letter-spacing:.2px}.logo .dot{color:var(--brand)}
.nav{display:flex;gap:18px;flex-wrap:wrap}.nav a{color:#334155}
.layout{display:grid;grid-template-columns:260px 1fr;gap:20px;max-width:1200px;margin:0 auto;padding:16px 24px}
.sidebar{position:sticky;top:70px;align-self:start;max-height:calc(100vh - 86px);overflow:auto;background:#fff;border:1px solid var(--border);border-radius:14px;box-shadow:var(--shadow);padding:12px}
.sidebar-title{font-weight:800;color:#0b1220;font-size:15px;padding:6px 8px 10px;border-bottom:1px solid #eef2f7;margin-bottom:8px}
.side-list a{display:block;padding:10px;border-radius:10px;color:#334155}.side-list a:hover{background:#f5f8ff}
.side-list a.active{background:#e9f1ff;color:#0b1220;font-weight:700;border:1px solid #d9e7ff}
.content>.container{padding-top:0}
.hero{background:linear-gradient(180deg,#fff 0%,#f7f9ff 100%);border:1px solid var(--border);border-radius:16px;padding:28px;box-shadow:var(--shadow)}
.section-title{margin:24px 0 10px;font-size:22px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px}
.card{display:block;background:var(--card);border:1px solid var(--border);border-radius:16px;padding:16px;box-shadow:var(--shadow);transition:transform .15s ease}
.card:hover{transform:translateY(-2px)}.card-title{font-weight:800}.card-desc{color:#64748b;font-size:14px}
main h1{margin:10px 0 8px}
.tool-desc{margin:0 0 8px;color:#475569}
.tool{display:grid;grid-template-columns:1fr 1fr;gap:16px;max-width:920px;margin:6px 0;padding:16px;border:1px solid var(--border);border-radius:16px;background:#fff;box-shadow:var(--shadow)}
.pane h3{margin:0 0 6px}
.input, select{width:100%;padding:12px;border:1px solid var(--border);border-radius:12px;margin:6px 0;min-height:44px}
.result{border:1px dashed var(--border);border-radius:12px;padding:12px;min-height:64px;font-weight:700}
.note{font-size:14px;color:#64748b}
.ad{min-height:240px;border:1px dashed var(--border);border-radius:14px;margin:18px 0;display:flex;align-items:center;justify-content:center;color:#94a3b8;background:#fff}
.footer{margin-top:28px;border-top:1px solid var(--border);padding:28px 24px;color:#64748b}
ul.clean{padding-left:18px}
.blog-wrap{max-width:820px;margin:0 auto;padding:24px}
.blog-item{display:block;background:#fff;border:1px solid var(--border);border-radius:16px;padding:18px;margin:14px 0;box-shadow:var(--shadow);text-decoration:none}
.blog-item .title{font-weight:800;font-size:20px;color:#0b1220;margin:0 0 6px}
.blog-item .desc{color:#475569;margin:0}
.blog-empty{color:#94a3b8;border:1px dashed var(--border);border-radius:14px;padding:28px;text-align:center}
.accordion{max-width:900px;margin:16px 0}.acc-item{border:1px solid var(--border);border-radius:14px;background:#fff;margin-bottom:12px;box-shadow:var(--shadow)}
.acc-btn{width:100%;text-align:left;padding:14px 18px;background:#fff;border:0;font-weight:700;font-size:16px;color:var(--ink);cursor:pointer;display:flex;justify-content:space-between;align-items:center}
.acc-panel{padding:0 18px 16px;color:#475569}.caret::before{content:"▸";transition:transform .2s ease;display:inline-block}
.acc-btn[aria-expanded="true"] .caret::before{transform:rotate(90deg)}
@media(max-width:1000px){.layout{grid-template-columns:1fr;padding:12px 16px}.sidebar{display:none}}