.app-shell{min-height:100vh;padding:1.5rem;display:flex;justify-content:center;align-items:center;background:linear-gradient(140deg,#17356b,#1f7986 45%,#f0b152)}.sudoku-panel{width:min(100%,980px);background:#ffffffed;border-radius:20px;box-shadow:0 20px 48px #0003;display:grid;grid-template-columns:1fr 320px;gap:1.5rem;padding:1.5rem}.board-column{display:flex;justify-content:center;align-items:center}.grid-wrap{border:3px solid #102c46;border-radius:10px;overflow:hidden;background:#102c46}.grid-row{display:flex}.grid-cell{width:3rem;height:3rem;border:1px solid #c7d0dc;background:#fff;text-align:center;font-size:1.25rem;line-height:1;font-weight:700;color:#16557a;outline:none;transition:background-color .2s ease,transform .2s ease}.grid-cell:focus{background:#eef8ff}.cell-block-right{border-right:3px solid #102c46}.cell-block-bottom{border-bottom:3px solid #102c46}.cell-given{background:#e5eaef;color:#2a3138}.cell-filled{background:#f7fcff}.cell-conflict{background:#ffe1e1;color:#ab1a1a}.controls-column{display:flex;flex-direction:column;gap:1rem}.title{margin:0;font-size:2rem;color:#112d4a}.status{margin:.25rem 0 0;color:#415161;font-weight:600}.card{background:#f8fbfd;border:1px solid #dde7ef;border-radius:12px;padding:.85rem}.label{display:block;margin:0 0 .4rem;font-size:.9rem;font-weight:700;color:#213850}.slider{width:100%;accent-color:#1777b7}.meter-row{display:flex;justify-content:space-between;font-size:.75rem;color:#6c7d8f}.stats-row{display:grid;grid-template-columns:repeat(2,1fr);gap:.75rem}.stat-box{background:#edf4fb;border-radius:10px;padding:.65rem;text-align:center}.stat-box strong{display:block;font-size:1.25rem;color:#173f64}.stat-box span{font-size:.78rem;color:#4a6178}.button-stack{display:flex;flex-direction:column;gap:.55rem}.btn{border:0;border-radius:10px;padding:.7rem .9rem;min-height:44px;font-size:.95rem;font-weight:700;cursor:pointer}.btn-primary{background:linear-gradient(135deg,#0d6cab,#0fa3b1);color:#fff}.btn-stop{background:#cc3f3f;color:#fff}.btn-ghost{background:#fff;color:#23425f;border:1px solid #c7d6e3}.sample-row{display:grid;grid-template-columns:repeat(2,1fr);gap:.55rem}.btn-sample{background:#e9f3fb;color:#14507a;border:1px solid #c6dfef}.hint-box{font-size:.82rem;color:#4f6478;background:#f3f7fb;border-radius:10px;padding:.75rem}@media(max-width:860px){.app-shell{align-items:flex-start;padding:.75rem}.sudoku-panel{grid-template-columns:1fr;gap:1rem;padding:1rem;border-radius:14px}.controls-column{gap:.75rem}.title{font-size:1.6rem}.grid-wrap{width:100%;max-width:100%}.grid-row{width:100%}.grid-cell{width:calc((100vw - 2.6rem) / 9);height:calc((100vw - 2.6rem) / 9);max-width:2.9rem;max-height:2.9rem;font-size:1.05rem;padding:0}}@media(max-width:420px){.app-shell{padding:.5rem}.sudoku-panel{padding:.8rem}.grid-cell{width:calc((100vw - 2rem) / 9);height:calc((100vw - 2rem) / 9);font-size:.96rem}.stats-row{gap:.5rem}}