@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700;800&family=Noto+Sans+KR:wght@400;500;600;700;800&display=swap');:root{--navy:#18243c;--muted:#778197;--blue:#5865e8;--bg:#f5f7fb;--line:#e8ecf3}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--navy);font-family:'DM Sans','Noto Sans KR',sans-serif}.top{height:72px;background:#fff;border-bottom:1px solid #e9edf4;display:flex;align-items:center}.nav{max-width:1000px;width:100%;margin:auto;padding:0 24px;display:flex;align-items:center;justify-content:space-between}.logo{font-weight:800;font-size:22px;letter-spacing:-1px;text-decoration:none;color:var(--navy)}.logo b{color:var(--blue)}.nav-actions{display:flex;align-items:center;gap:18px}.nav-actions a{color:#657088;text-decoration:none;font-size:13px;font-weight:700}.wrap{max-width:1000px;margin:auto;padding:0 24px}.hero{margin:42px auto 22px}.eyebrow{display:inline-flex;align-items:center;color:var(--blue);background:#eef0ff;border-radius:99px;padding:7px 12px;font-size:12px;font-weight:800}.hero h1{font-size:clamp(32px,5vw,46px);letter-spacing:-2px;line-height:1.15;margin:16px 0 10px}.hero p{color:var(--muted);font-size:15px;line-height:1.7;margin:0}.play-card{max-width:620px;margin:0 auto 24px;padding:20px;border:1px solid var(--line);border-radius:20px;background:#fff;box-shadow:0 8px 30px #2334580b}.topline{display:flex;justify-content:space-between;gap:8px;align-items:center;color:var(--muted);font-size:12px;font-weight:700}.topline strong{color:var(--navy)}.difficulty-select{display:flex;gap:8px;margin:14px 0}.mode-btn{flex:1;border:1px solid var(--line);border-radius:11px;background:#fff;color:var(--navy);padding:10px;font:inherit;font-size:13px;font-weight:800;cursor:pointer}.mode-btn.selected{background:#eef0ff;border-color:#b9c0ff;color:#414fce}.mode-btn:disabled{opacity:.55;cursor:not-allowed}.board{display:grid;grid-template-columns:repeat(9,minmax(0,1fr));width:min(100%,450px);aspect-ratio:1;margin:0 auto;border:2px solid #58627a;border-radius:5px;overflow:hidden;background:#fff}.cell{min-width:0;padding:0;border:0;border-right:1px solid #dce1eb;border-bottom:1px solid #dce1eb;background:#fff;color:#31415d;font:700 clamp(13px,3.7vw,21px) 'DM Sans','Noto Sans KR',sans-serif;cursor:pointer;touch-action:manipulation}.cell.box-right{border-right:2px solid #707b92}.cell.box-bottom{border-bottom:2px solid #707b92}.cell.given{font-weight:800;color:#243149}.cell.same-row,.cell.same-col{background:#f4f6fc}.cell.same-number{background:#e5e9ff;color:#3445c1}.cell.selected{background:#cfd5ff!important;box-shadow:inset 0 0 0 2px #5865e8}.cell.conflict,.cell.wrong{background:#ffe5e5!important;color:#a52c37}.cell.hinted{background:#e4f6ec!important;color:#176846}.cell:focus-visible{outline:2px solid #5865e8;outline-offset:-3px;z-index:1}.numberpad{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:7px;margin:14px auto 0;max-width:450px}.numberpad button{min-height:43px;border:1px solid var(--line);border-radius:10px;background:#f9faff;color:#33415e;font:inherit;font-size:15px;font-weight:700;cursor:pointer;touch-action:manipulation}.numberpad button:hover:not(:disabled){background:#eef0ff;border-color:#b8c0ff}.numberpad button.erase{font-size:12px}.numberpad button:disabled{opacity:.5;cursor:not-allowed}.action-row{display:flex;gap:8px;justify-content:center;margin-top:14px}.btn{border:0;border-radius:11px;padding:11px 15px;font:inherit;font-size:13px;font-weight:800;cursor:pointer}.btn.primary{background:var(--blue);color:#fff;box-shadow:0 6px 14px #5865e830}.btn.secondary{background:#eef0ff;color:#414fce}.btn:disabled{opacity:.5;cursor:not-allowed}.btn:focus-visible,.mode-btn:focus-visible,.numberpad button:focus-visible{outline:3px solid #9ca5ff;outline-offset:2px}.meta-row{display:flex;justify-content:center;gap:24px;margin-top:12px;color:var(--muted);font-size:12px}.meta-row strong{color:var(--navy)}.status{margin:12px 0 0;padding:11px 13px;border-radius:12px;background:#f5f6fa;color:#5e6a80;font-size:13px;line-height:1.6;text-align:center}.guide{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:34px 0 56px}.guide-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:20px}.guide-card h2{font-size:16px;margin:0 0 9px}.guide-card p,.guide-card li{font-size:13px;line-height:1.7;color:#67738a}.guide-card p{margin:0}.guide-card ul{margin:0;padding-left:19px}.guide-card li+li{margin-top:5px}.footer{border-top:1px solid #e6eaf1;background:#fff;text-align:center;color:#8992a3;padding:25px;font-size:12px}@media(max-width:650px){.top{height:62px}.nav{padding:0 18px}.nav-actions{gap:12px}.nav-actions a{font-size:12px}.wrap{padding:0 18px}.hero{margin:32px auto 18px}.hero h1{letter-spacing:-1.4px}.play-card{padding:14px;border-radius:16px}.topline{font-size:11px}.board{border-width:2px}.cell{font-size:clamp(12px,4vw,17px)}.numberpad{gap:5px}.numberpad button{min-height:40px}.action-row{display:grid;grid-template-columns:1fr 1fr}.action-row .btn:first-child{grid-column:1/-1}.guide{grid-template-columns:1fr;gap:10px;margin:26px 0 42px}.guide-card{padding:17px}}