:root{--ink:#273348;--muted:#8390a3;--blue:#4e83f5;--blue-soft:#eaf1ff;--line:#d9e0ec;--paper:#fff;--bg:#f5f7fb;--danger:#eb6671}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:"DM Sans",system-ui,sans-serif;min-height:100dvh}.app-shell{width:min(1160px,100%);margin:auto;padding:20px 34px 32px}.topbar{height:54px;display:flex;align-items:center;justify-content:space-between}.icon-button,.text-button{border:0;background:transparent;color:var(--ink);font:inherit;cursor:pointer}.menu{width:40px;padding:10px 6px;text-align:left}.menu i{display:block;width:20px;height:2px;background:var(--ink);margin:4px 0;border-radius:9px}.brand{position:absolute;left:50%;transform:translateX(-50%);text-decoration:none;color:var(--ink);font-weight:700;letter-spacing:2.5px;font-size:16px;display:flex;gap:7px;align-items:center}.brand-mark{color:#fff;background:var(--blue);width:22px;height:22px;display:grid;place-items:center;border-radius:6px;letter-spacing:0;font-family:Fraunces;font-size:17px}.top-actions{display:flex;gap:11px;align-items:center}.streak{border:0;background:#fff2db;color:#cc8d21;border-radius:20px;padding:7px 10px;font-weight:700}.avatar{width:34px;height:34px;border-radius:50%;border:0;background:#dce8ff;color:#416ecc;font-weight:700}.game-header{display:flex;justify-content:space-between;align-items:end;margin:31px 0 27px}.eyebrow{color:var(--muted);font-size:11px;font-weight:700;letter-spacing:1.5px;margin:0 0 4px}.game-header h1{margin:0;font-family:Fraunces,serif;font-size:30px;letter-spacing:-1px}.game-header h1 span{color:var(--blue)}.new-game{border:1px solid var(--line);background:#fff;border-radius:9px;padding:10px 13px;color:var(--ink);font:600 13px inherit;cursor:pointer}.game-layout{display:grid;grid-template-columns:112px minmax(410px,550px) 210px;gap:38px;justify-content:center;align-items:center}.left-rail{display:grid;gap:15px}.stat-card{background:#fff;border-radius:11px;padding:15px 13px;box-shadow:0 2px 12px #344b7410}.stat-card small,.mistakes small{color:var(--muted);font-size:10px;font-weight:700;letter-spacing:1px}.stat-card strong{display:block;font-size:18px;margin-top:4px}.board-area{width:100%}.progress-wrap{height:5px;background:#e5eaf3;border-radius:9px;margin-bottom:12px;overflow:hidden}.progress{background:var(--blue);height:100%;width:0;border-radius:inherit;transition:width .25s}.board{aspect-ratio:1;width:100%;display:grid;grid-template-columns:repeat(9,1fr);background:var(--line);gap:1px;border:2px solid var(--ink);border-radius:5px;overflow:hidden;box-shadow:0 11px 30px #31436417}.cell{border:0;background:#fff;color:var(--ink);font:700 clamp(18px,3vw,25px) Fraunces,serif;cursor:pointer;position:relative;min-width:0}.cell:nth-child(3n){border-right:2px solid var(--ink)}.cell:nth-child(9n){border-right:0}.cell:nth-child(n+19):nth-child(-n+27),.cell:nth-child(n+46):nth-child(-n+54){border-bottom:2px solid var(--ink)}.cell.given{color:#273348;cursor:default;background:#fcfdff}.cell.selected{background:#cbdcff}.cell.related{background:var(--blue-soft)}.cell.same{color:#2163e1}.cell.wrong{color:var(--danger);background:#fff0f1}.notes{display:grid;grid-template-columns:repeat(3,1fr);font:600 clamp(7px,1.15vw,10px) "DM Sans";padding:10%;color:#5178bb}.note{display:grid;place-items:center}.helper{text-align:center;color:var(--muted);font-size:12px;margin:12px 0 0}.side-panel{background:#fff;border-radius:14px;padding:18px;box-shadow:0 2px 12px #344b7410}.panel-head{display:flex;align-items:center;justify-content:space-between}.panel-head h2{font:700 15px inherit;margin:0}.text-button{font-size:12px;color:var(--blue);font-weight:700}.mistakes{margin:18px 0;border-radius:9px;background:#fff7f7;display:flex;gap:10px;padding:12px;color:#de6670}.mistakes span{font-size:22px}.mistakes strong{display:block;font-size:13px;color:var(--ink);margin-top:3px}.difficulty-list{border-top:1px solid #edf0f5;padding-top:8px}.difficulty-list button{display:grid;grid-template-columns:14px 1fr auto;align-items:center;gap:7px;width:100%;padding:10px 1px;border:0;background:#fff;color:var(--ink);font:600 12px inherit;text-align:left;cursor:pointer}.difficulty-list button.active{color:var(--blue)}.difficulty-list em{font-size:10px;color:var(--muted);font-style:normal}.level-dot{width:8px;height:8px;border-radius:50%;background:#83d6a8}.level-dot.medium{background:#f5c266}.level-dot.hard{background:#e9818a}.panel-note{color:var(--muted);font-size:11px;line-height:1.5;margin:12px 0 0}.controls{width:min(550px,100%);margin:26px auto 0}.number-pad{display:grid;grid-template-columns:repeat(9,1fr);gap:8px}.number-pad button{aspect-ratio:1;border:0;border-radius:9px;background:#fff;color:var(--ink);font:700 19px Fraunces,serif;box-shadow:0 2px 9px #344b7410;cursor:pointer}.number-pad button.used{opacity:.34}.number-pad button:active,.tool:active{transform:scale(.95)}.tool-row{display:grid;grid-template-columns:repeat(4,1fr);gap:9px;margin-top:14px}.tool{border:0;background:transparent;color:var(--muted);font:600 11px inherit;display:grid;place-items:center;gap:4px;cursor:pointer;position:relative;padding:4px}.tool-icon{width:35px;height:35px;border-radius:10px;background:#fff;color:#61708b;display:grid;place-items:center;font-size:20px;box-shadow:0 2px 9px #344b7410}.tool.active .tool-icon{background:var(--blue);color:#fff}.tool b{position:absolute;top:-5px;right:17%;font:700 9px inherit;background:#e6ebf4;padding:2px 4px;border-radius:5px;color:#69778b}.tool.active b{background:#dbe8ff;color:#4276df}.modal-backdrop{position:fixed;inset:0;background:#1d2a4066;display:grid;place-items:center;padding:20px;z-index:5}.hidden{display:none}.modal{background:#fff;width:min(400px,100%);padding:28px;border-radius:18px;box-shadow:0 22px 70px #101a2e40;position:relative}.modal-close{position:absolute;right:14px;top:10px;border:0;background:transparent;font-size:26px;color:var(--muted);cursor:pointer}.modal h2{font:700 24px Fraunces;margin:0 0 8px}.modal p{color:var(--muted);font-size:13px;line-height:1.5}.history-item{border-top:1px solid #edf0f5;padding:10px 0;font-size:13px;display:flex;justify-content:space-between}.history-item span{color:var(--muted)}.modal button.choice{border:0;background:var(--blue);color:#fff;border-radius:9px;padding:10px 15px;font:700 13px inherit;margin:6px 5px 0 0;cursor:pointer}.toast{position:fixed;bottom:max(20px,env(safe-area-inset-bottom));left:50%;transform:translateX(-50%);background:#283850;color:#fff;padding:11px 16px;border-radius:10px;font-size:13px;z-index:8;box-shadow:0 8px 24px #101a2e44}@media(max-width:760px){.app-shell{padding:calc(10px + env(safe-area-inset-top)) 15px calc(15px + env(safe-area-inset-bottom))}.topbar{height:43px}.game-header{margin:21px 2px 17px}.game-header h1{font-size:26px}.game-layout{display:block}.left-rail{display:flex;grid-template-columns:repeat(3,1fr);gap:8px;margin:0 0 14px}.stat-card{flex:1;padding:9px 10px}.stat-card strong{font-size:16px}.side-panel{display:none}.board-area{width:min(100%,530px);margin:auto}.helper{margin-top:9px}.controls{margin-top:17px}.number-pad{gap:6px}.number-pad button{font-size:18px}.tool-row{margin-top:10px}.tool-icon{width:34px;height:34px}.brand{font-size:14px}.streak{padding:6px 8px}.avatar{width:31px;height:31px}}@media(max-width:390px){.game-header h1{font-size:23px}.new-game{padding:8px 10px}.left-rail{margin-bottom:10px}.stat-card{padding:7px 8px}.stat-card small{font-size:9px}.number-pad button{font-size:16px}.tool-row{gap:4px}}