.letter-window{background:var(--white);border:1px solid var(--border);border-radius:var(--r-xl);box-shadow:var(--sh-4);padding:30px;position:relative}.letter-window .illus-tag{background:var(--ink);color:#fff;font-family:var(--font-mono), monospace;border-radius:var(--r-pill);letter-spacing:.04em;padding:5px 12px;font-size:10px;position:absolute;top:-11px;left:24px}.letter-block{margin-bottom:14px}.letter-block:last-child{margin-bottom:0}.letter-line{background:var(--border);border-radius:3px;height:6px;margin-bottom:6px}.letter-label{font-family:var(--font-mono), monospace;letter-spacing:.07em;color:var(--grey-soft);text-transform:uppercase;margin-bottom:6px;font-size:9px}.letter-preview{background:var(--white);border:1px solid var(--border);border-radius:var(--r-lg);box-shadow:var(--sh-2);padding:22px}.flag-txt{color:var(--ink-soft);background:#fdebc8;border-radius:4px;margin-bottom:10px;padding:8px 10px;font-size:13px;position:relative}.flag-txt:last-child{margin-bottom:0}.flag-txt:after{content:"";border:1.5px dashed var(--amber);border-radius:6px;position:absolute;inset:-2px}.flag-tag{color:#946b0c;margin-top:4px;font-size:10px;font-weight:700;display:block}.flag-list .flag-card:nth-child(3){border-left-color:var(--violet)}.step-card ul{color:var(--grey-soft);margin:0;padding:0;font-size:12px;list-style:none}.step-card li{padding:2px 0}.step-span2{grid-column:span 2}@media (max-width:560px){.step-span2{grid-column:span 1}}.match-demo{grid-template-columns:1fr auto 1fr auto 1fr;align-items:center;gap:8px;margin-top:10px;display:grid}@media (max-width:560px){.match-demo{grid-template-columns:1fr}}.match-col{background:var(--canvas);border:1px solid var(--border);border-radius:var(--r-sm);color:var(--ink-soft);padding:8px 10px;font-size:10.5px}.match-col .mlbl{font-family:var(--font-mono), monospace;color:var(--grey-soft);text-transform:uppercase;margin-bottom:4px;font-size:8.5px;display:block}.match-col.result{color:var(--violet-deep);background:#f5f3ff;border-color:#6e56f859;font-weight:600}.match-arrow{color:var(--grey-soft);text-align:center;font-size:13px}@media (max-width:560px){.match-arrow{transform:rotate(90deg)}}.structure-list{flex-direction:column;gap:10px;max-width:640px;margin:0 auto;display:flex}.structure-item{background:var(--white);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--sh-1);align-items:flex-start;gap:14px;padding:16px 18px;display:flex}.structure-num{background:var(--violet);color:#fff;width:26px;height:26px;font-family:var(--font-sora), sans-serif;border-radius:50%;flex:none;justify-content:center;align-items:center;font-size:12px;font-weight:800;display:flex}.structure-item h3{margin-bottom:3px;font-size:14.5px}.structure-item p{color:var(--grey);margin:0;font-size:13px}