:root{--ink:#1f2022;--paper:#f5f5f3;--white:#fff;--line:#d7d7d3;--muted:#696a6d;--gold:#d99a00;--orange:#d45b22;--red:#a7332c}*{box-sizing:border-box}html{font-size:16px}body{margin:0;background:var(--paper);color:var(--ink);font-family:Pretendard,"Noto Sans KR",Arial,sans-serif}.topbar{height:82px;padding:0 clamp(24px,5vw,72px);background:var(--ink);color:#fff;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;flex-direction:column;gap:4px}.brand strong{font-size:1.15rem}.eyebrow{font-size:.72rem;font-weight:800;letter-spacing:.14em;color:#e6b33d}.status{font-size:.86rem;color:#d7d7d7;display:flex;align-items:center;gap:9px}.status span{width:8px;height:8px;border-radius:50%;background:var(--gold)}main{width:min(1160px,calc(100% - 40px));margin:0 auto;padding:54px 0 48px}.intro{display:grid;grid-template-columns:1.1fr .9fr;align-items:end;gap:64px;margin-bottom:42px}.kicker{margin:0 0 13px;color:var(--orange);font-size:.78rem;font-weight:900;letter-spacing:.18em}.intro h1{font-family:Georgia,"Noto Serif KR",serif;font-size:clamp(2.35rem,5vw,4.7rem);line-height:1.06;letter-spacing:-.055em;margin:0}.summary{margin:0;padding-left:24px;border-left:4px solid var(--gold);font-size:1rem;line-height:1.8;color:#555;max-width:500px}.grade-tabs{display:grid;grid-template-columns:repeat(3,1fr);border:1px solid var(--line);background:var(--white)}.grade-tab{border:0;border-right:1px solid var(--line);background:transparent;padding:22px 24px;color:var(--muted);display:flex;align-items:center;gap:15px;text-align:left;cursor:pointer;font-size:1rem}.grade-tab:last-child{border-right:0}.grade-tab b{font-family:Georgia,serif;font-size:1.55rem;color:#aaa}.grade-tab span{font-weight:800}.grade-tab:hover{background:#f0f0ed}.grade-tab.active{background:var(--ink);color:#fff}.grade-tab.active b{color:var(--gold)}.catalog{background:#fff;border:1px solid var(--line);border-top:0;padding:34px}.catalog-head{display:flex;justify-content:space-between;align-items:end;padding-bottom:23px;border-bottom:2px solid var(--ink)}.catalog-head span{font-size:.75rem;font-weight:900;letter-spacing:.15em;color:var(--gold)}.catalog-head h2{margin:7px 0 0;font-size:1.6rem;letter-spacing:-.04em}.catalog-head p{margin:0;color:var(--muted);font-size:.9rem}.book-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;padding-top:24px}.book-card{min-height:205px;border:1px solid var(--line);padding:24px;display:flex;flex-direction:column;position:relative;transition:.18s ease;background:#fff}.book-card:before{content:"";position:absolute;left:0;top:0;width:5px;height:100%;background:var(--accent,var(--gold))}.book-card:hover{transform:translateY(-3px);border-color:#999;box-shadow:0 12px 24px rgba(0,0,0,.08)}.publisher{font-size:.78rem;font-weight:800;color:var(--accent,var(--gold));margin-bottom:8px}.book-card h3{font-size:1.3rem;margin:0 0 7px}.book-card .lessons{font-family:Georgia,"Noto Serif KR",serif;font-size:1rem;color:#4c4c4c;margin:0}.book-meta{margin-top:18px;font-size:.82rem;color:#777}.open-btn{margin-top:auto;display:flex;align-items:center;justify-content:space-between;color:var(--ink);font-weight:900;text-decoration:none;border-top:1px solid #ecece8;padding-top:15px}.open-btn i{font-style:normal;font-size:1.35rem;color:var(--accent,var(--gold))}.placeholder{grid-column:1/-1;padding:32px;border:1px dashed #aaa;background:#fafafa;color:#666;line-height:1.7}footer{width:min(1160px,calc(100% - 40px));margin:0 auto 40px;padding-top:18px;border-top:1px solid #ccc;display:flex;justify-content:space-between;color:#777;font-size:.78rem}@media(max-width:760px){.topbar{height:72px}.status{display:none}main{width:min(100% - 24px,1160px);padding:32px 0}.intro{grid-template-columns:1fr;gap:24px;margin-bottom:28px}.intro h1{font-size:2.7rem}.summary{padding-left:17px}.grade-tabs{grid-template-columns:1fr}.grade-tab{border-right:0;border-bottom:1px solid var(--line);padding:16px 18px}.grade-tab:last-child{border-bottom:0}.catalog{padding:22px 17px}.catalog-head{align-items:start}.catalog-head p{text-align:right}.book-grid{grid-template-columns:1fr}.book-card{min-height:185px}footer{width:calc(100% - 24px);flex-direction:column;gap:7px}}