.deep-dive{margin-top:24px;border:2px solid var(--ink);border-radius:14px;background:#fff;padding:24px;box-shadow:4px 4px 0 var(--ink)}.deep-dive-head{display:flex;align-items:center;gap:10px;margin-bottom:18px}.deep-dive-head span{display:grid;place-items:center;width:36px;height:36px;border:2px solid var(--ink);border-radius:9px;background:var(--yellow)}.deep-dive-head h3{margin:0;font-size:21px}.deep-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}.deep-item{padding:16px;border-radius:10px;background:#f7f7f7}.deep-item.rule{background:#edf2ff}.deep-item.error{background:#ffecef}.deep-item.practice-tip{background:#e7f8f1}.deep-item b{display:block;margin-bottom:7px}.deep-item p{margin:0;line-height:1.7;font-size:14px}.sentence-breakdown{display:flex;gap:7px;flex-wrap:wrap;margin-top:8px}.sentence-breakdown span{padding:5px 9px;border:1px solid #aaa;border-radius:6px;background:#fff;font-weight:800;font-size:13px}.sound-depth{margin-top:18px;padding:18px;border:2px dashed var(--blue);border-radius:12px;background:#f4f6ff}.sound-depth h4{margin:0 0 10px}.sound-depth-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.sound-depth-grid div{background:#fff;padding:12px;border-radius:8px}.sound-depth-grid b{color:var(--blue);font-size:18px}.sound-depth-grid p{font-size:12px;line-height:1.6;margin:5px 0}.word-depth{max-width:1100px;margin:24px auto 0;background:#fff8d2;border:2px solid var(--ink);border-radius:14px;padding:22px;display:grid;grid-template-columns:1fr 1fr;gap:24px}.word-depth h3{margin:0 0 10px}.word-depth p{line-height:1.7;margin:5px 0}.word-depth .review-steps{display:flex;gap:6px;flex-wrap:wrap}.review-steps span{background:#fff;border:1px solid var(--ink);border-radius:7px;padding:6px 9px;font-size:12px;font-weight:800}@media(max-width:650px){.deep-grid,.sound-depth-grid,.word-depth{grid-template-columns:1fr}.deep-dive{padding:18px}}