:root{--blue:#0f6fc6;--blue2:#0a4fa0;--ink:#17324d;--muted:#63778c;--line:#cfe2f0;--orange:#f59a23;--orange2:#e77c0a;--green:#24a96b;--paper:#f4f9fd;--shadow:0 12px 30px rgba(26,72,112,.12)}
*{box-sizing:border-box}html,body{margin:0;min-height:100%;font-family:Nunito,"Trebuchet MS",Arial,sans-serif;color:var(--ink);background:linear-gradient(180deg,#eef7fc,#f7fbfe)}button,input{font:inherit}.app-shell{min-height:100vh;display:flex;flex-direction:column}.topbar{display:flex;align-items:center;justify-content:space-between;gap:18px;padding:14px 20px;background:linear-gradient(135deg,#0f78cf,#0b55a6);color:#fff;box-shadow:0 5px 14px rgba(7,61,112,.22);z-index:5}.brand-kicker{font-size:.72rem;font-weight:900;letter-spacing:.08em;text-transform:uppercase;opacity:.84}.topbar h1{margin:2px 0 0;font-size:clamp(1.2rem,2.15vw,1.85rem);line-height:1.08}.top-actions{display:flex;gap:8px}.icon-btn{min-height:42px;padding:0 13px;border:1px solid rgba(255,255,255,.24);border-radius:12px;background:rgba(255,255,255,.12);color:#fff;font-weight:900;cursor:pointer}.icon-btn:hover{background:rgba(255,255,255,.2)}
.modebar{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;padding:9px 14px;background:#fff;border-bottom:1px solid #d9e8f3;box-shadow:0 3px 10px rgba(45,84,119,.06);z-index:4}.mode-btn{min-height:44px;border:1px solid #c6dbeb;border-radius:13px;background:linear-gradient(180deg,#fff,#f0f7fc);color:#31536f;font-weight:900;cursor:pointer}.mode-btn.is-active{background:linear-gradient(180deg,#ffa52e,#ef820d);border-color:#e37806;color:#fff;box-shadow:0 6px 12px rgba(235,126,12,.22)}
.workspace{flex:1;display:grid;grid-template-columns:minmax(230px,285px) minmax(0,1fr);gap:14px;padding:14px;min-height:0}.control-panel{display:flex;flex-direction:column;gap:12px}.control-card{padding:14px;border:1px solid var(--line);border-radius:20px;background:#fff;box-shadow:var(--shadow)}.control-label{margin-bottom:10px;color:#0f6fc6;font-size:.78rem;font-weight:950;letter-spacing:.08em;text-transform:uppercase}.number-picker{display:grid;grid-template-columns:52px 1fr 52px;gap:8px;align-items:center}.number-picker input{width:100%;height:66px;border:2px solid #bad8ed;border-radius:16px;text-align:center;font-size:2rem;font-weight:950;color:#18426d;outline:none;background:#fafdff}.number-picker input:focus{border-color:#1681d8;box-shadow:0 0 0 4px rgba(22,129,216,.11)}.step-btn{height:54px;border:0;border-radius:14px;background:linear-gradient(180deg,#21a0ed,#176bcf);color:#fff;font-size:1.7rem;font-weight:900;cursor:pointer;box-shadow:0 7px 13px rgba(23,107,207,.2)}.number-presets{display:grid;grid-template-columns:repeat(4,1fr);gap:6px;margin-top:10px}.number-presets button{height:36px;border:1px solid #d2e4f1;border-radius:10px;background:#f4f9fd;color:#315674;font-weight:900;cursor:pointer}.action-btn{width:100%;min-height:48px;margin-top:8px;border:0;border-radius:14px;color:#fff;font-weight:950;cursor:pointer;box-shadow:0 7px 14px rgba(30,92,143,.14)}.action-btn:disabled{opacity:.38;cursor:not-allowed;box-shadow:none}.bundle{background:linear-gradient(180deg,#2ab778,#168c58)}.explode{background:linear-gradient(180deg,#f5a12d,#e7760a)}.normalize,.next{background:linear-gradient(180deg,#198ee1,#0f65bd)}.tip{margin-top:10px;color:#708397;font-size:.76rem;line-height:1.35}.free-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}.mini-action{min-height:46px;border:1px solid #cbdfea;border-radius:13px;background:#f5faff;color:#214f72;font-weight:900;cursor:pointer}.ten-add{border-color:#9ecfea;background:#eaf7ff}.one-add{border-color:#f3c48e;background:#fff6e9}.ten-remove,.one-remove{background:#f7f8fa}.answer-row{display:grid;grid-template-columns:1fr auto;gap:8px}.answer-row input{min-width:0;height:58px;border:2px solid #c6dfef;border-radius:14px;text-align:center;font-size:1.6rem;font-weight:950;outline:0}.check-btn{padding:0 14px;border:0;border-radius:14px;background:linear-gradient(180deg,#2cb979,#168c58);color:#fff;font-weight:950;cursor:pointer}.feedback{min-height:34px;margin-top:9px;padding:8px 10px;border-radius:10px;font-size:.8rem;font-weight:850;line-height:1.25}.feedback:empty{padding:0}.feedback.ok{background:#e5f8ef;color:#117a4c}.feedback.no{background:#fff0ee;color:#ad3d30}.feedback.warn{background:#fff6df;color:#8a6514}
.board-wrap{min-width:0;display:flex;flex-direction:column;gap:10px}.value-strip{display:grid;grid-template-columns:1fr 1.2fr 1fr;gap:10px}.value-strip.is-hidden,.equation-bar.is-hidden{visibility:hidden}.value-box{min-height:76px;padding:9px 12px;border:1px solid var(--line);border-radius:18px;background:#fff;text-align:center;box-shadow:0 6px 16px rgba(30,76,116,.07)}.value-box span{display:block;color:#708397;font-size:.72rem;font-weight:850}.value-box strong{display:block;margin-top:2px;color:#146fbe;font-size:1.65rem;line-height:1;font-weight:950}.value-box em{display:block;margin-top:5px;color:#61788e;font-size:.78rem;font-style:normal;font-weight:850}.main-number{background:linear-gradient(180deg,#fffaf3,#fff0d9);border-color:#f2c88d}.main-number strong{color:#dc7610;font-size:2rem}
.board{flex:1;display:grid;grid-template-columns:1fr 1fr;gap:12px;min-height:420px}.place-zone{display:flex;flex-direction:column;min-width:0;overflow:hidden;border:2px solid #b9daf0;border-radius:24px;background:#fff;box-shadow:var(--shadow)}.ones-zone{border-color:#f1c58f}.zone-head{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 15px;background:linear-gradient(180deg,#eaf7ff,#dff1fb);border-bottom:1px solid #c3deee}.ones-zone .zone-head{background:linear-gradient(180deg,#fff6e9,#ffedd3);border-bottom-color:#f0d1a8}.zone-kicker{font-size:.68rem;font-weight:950;letter-spacing:.09em;color:#1172bd}.ones-zone .zone-kicker{color:#c66a0c}.zone-head h2{margin:2px 0 0;font-size:1rem}.zone-badge{display:grid;place-items:center;min-width:48px;height:36px;border-radius:12px;background:#1279c8;color:#fff;font-weight:950}.ones-zone .zone-badge{background:#ef8a17}.material-area{flex:1;padding:16px;align-content:start}.rods{display:flex;flex-wrap:wrap;align-items:flex-start;gap:12px}.rod{width:44px;height:224px;padding:4px;display:grid;grid-template-rows:repeat(10,1fr);gap:2px;border:2px solid #0f73bf;border-radius:10px;background:#0f7bd0;box-shadow:0 8px 13px rgba(16,111,187,.18);cursor:default}.rod i{display:block;border-radius:3px;background:linear-gradient(180deg,#6bc4f4,#3ba7e8);border:1px solid rgba(255,255,255,.6)}.units{display:grid;grid-template-columns:repeat(10,minmax(24px,42px));gap:9px;justify-content:start}.unit{aspect-ratio:1;border:2px solid #d97810;border-radius:9px;background:linear-gradient(180deg,#ffc766,#f3a72f);box-shadow:0 5px 9px rgba(202,111,20,.15);cursor:default}.free-controls~* .rod,.free-controls~* .unit{cursor:pointer}.equation-bar{min-height:50px;display:flex;align-items:center;justify-content:center;padding:8px 14px;border-radius:17px;background:linear-gradient(90deg,#eaf6ff,#fff7e9);border:1px solid #d1e4f1;color:#244b6c;font-size:clamp(.9rem,1.4vw,1.12rem);font-weight:950;box-shadow:0 5px 14px rgba(30,76,116,.06)}
.app-footer{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:7px 16px;background:#e8f2f8;color:#60758a;border-top:1px solid #d0e1ec;font-size:.72rem;font-weight:800}.app-footer strong{color:#1c689f}
[hidden]{display:none!important}
@media(max-width:980px){.workspace{grid-template-columns:1fr}.control-panel{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));order:2}.board-wrap{order:1}.control-card{min-height:100%}.board{min-height:390px}.rod{height:190px}.units{grid-template-columns:repeat(10,minmax(22px,1fr))}}
@media(max-width:720px){.topbar{padding:10px 12px}.icon-btn span{display:none}.icon-btn{min-width:42px;padding:0 10px}.modebar{grid-template-columns:1fr 1fr;padding:7px}.mode-btn{min-height:40px;font-size:.78rem}.workspace{padding:8px;gap:8px}.control-panel{grid-template-columns:1fr}.value-strip{grid-template-columns:1fr 1fr}.main-number{grid-column:1/-1;grid-row:1}.board{grid-template-columns:1fr;min-height:auto}.place-zone{min-height:285px}.rod{height:180px;width:38px}.units{grid-template-columns:repeat(10,minmax(21px,1fr));gap:6px}.app-footer{font-size:.62rem}.app-footer span{display:none}}
@media(max-width:420px){.topbar h1{font-size:1rem}.brand-kicker{font-size:.58rem}.mode-btn{font-size:.7rem}.number-picker input{height:56px;font-size:1.7rem}.place-zone{min-height:255px}.material-area{padding:11px}.rod{height:160px;width:34px}.units{grid-template-columns:repeat(8,minmax(22px,1fr))}.value-box{min-height:66px}.value-box strong{font-size:1.45rem}.main-number strong{font-size:1.8rem}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}